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Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Develop baseline computational model for proactive welding stress  

Broader source: Energy.gov (indexed) [DOE]

Develop baseline computational model for proactive welding stress Develop baseline computational model for proactive welding stress management to suppress helium induced cracking during weld repair Develop baseline computational model for proactive welding stress management to suppress helium induced cracking during weld repair There are over 100 nuclear power plants operating in the U.S., which generate approximately 20% of the nation's electricity. These plants range from 15 to 40 years old. Extending the service lives of the current fleet of nuclear power plants beyond 60 years is imperative to allow for the environmentally-sustainable energy infrastructure being developed and matured. Welding repair of irradiated nuclear reactor materials (such as austenitic stainless steels) is especially challenging because of the

2

Residual stress patterns in steel welds  

SciTech Connect (OSTI)

Neutron strain scanning of residual stress is a valuable nondestructive tool for evaluation of residual stress in welds. The penetrating characteristic of neutrons permits mapping of strain patterns with a spatial resolution approaching 1mm at depths of 20mm in steels. While the overall patterns of the residual stress tensor in a weld are understood, the detailed patterns depend on welding process parameters and the effects of solid state transformation. The residual strain profiles in two multi-pass austenitic welds and a ferritic steel weld are presented. The stress-free lattice parameters within the fusion zone and the adjacent heat affected zone in the two austenitic welds show that the interpretation of residual stress from strains are affected by welding parameters. An interpretation of the residual strain pattern in the ferritic steel plate can be made using the strain measurements of a Gleeble test bar which has undergone the solid state austenite decomposition.

Spooner, S.; Hubbard, C.R.; Wang, X.L.; David, S.A.; Holden, T.M. [Oak Ridge National Lab., TN (United States); Root, J.H.; Swainson, I. [Atomic Energy of Canada Ltd., Chalk River, ON (Canada)

1994-12-31T23:59:59.000Z

3

An investigation of residual stress in welded joints  

E-Print Network [OSTI]

not extended beyond eight days time~ therefore the curve does not show com- plete relaxation of stress v!ith age of weld. However the figures "or the longitudinal stress compare favorably with that calculated by Houlton and iiartin (1) of 55, 000 psi... are bolted or doweled to a heavy cast iron or steel frame as shown which is of sufficient rigidity that all of the strain takes place in the specimen. The weld and the strain gage are separated sufficiently and the area between may be water cooled so II...

Moffat, William Hugh

1951-01-01T23:59:59.000Z

4

Insights Gained from Ultrasonic Testing of Piping Welds Subjected to the Mechanical Stress Improvement Process  

SciTech Connect (OSTI)

Pacific Northwest National Laboratory (PNNL) is assisting the United States Nuclear Regulatory Commission (NRC) in developing a position on the management of primary water stress corrosion cracking (PWSCC) in leak-before-break piping systems. Part of this involves determining whether inspections alone, or inspections plus mitigation, are needed. This work addresses the reliability of ultrasonic testing (UT) of cracks that have been mitigated by the mechanical stress improvement process (MSIP). The MSIP has been approved by the NRC (NUREG-0313) since 1986 and modifies residual stresses remaining after welding with compressive, or neutral, stresses near the inner diameter surface of the pipe. This compressive stress is thought to arrest existing cracks and inhibit new crack formation. To evaluate the effectiveness of the MSIP and the reliability of ultrasonic inspections, flaws were evaluated both before and after MSIP application. An initial investigation was based on data acquired from cracked areas in 325-mm-diameter piping at the Ignalina Nuclear Power Plant (INPP) in Lithuania. In a follow-on exercise, PNNL acquired and evaluated similar UT data from a dissimilar metal weld (DMW) specimen containing implanted thermal fatigue cracks. The DMW specimen is a carbon steel nozzle-to-safe end-to-stainless steel pipe section that simulates a pressurizer surge nozzle. The flaws were implanted in the nozzle-to-safe end Alloy 82/182 butter region. Results are presented on the effects of MSIP on specimen surfaces, and on UT flaw responses.

Anderson, Michael T.; Cinson, Anthony D.; Crawford, Susan L.; Diaz, Aaron A.; Moran, Traci L.

2010-12-01T23:59:59.000Z

5

Ultrasonic inspection of austenitic stainless steel welds with artificially produced stress corrosion cracks  

SciTech Connect (OSTI)

Austenitic stainless steel welds and nickel alloy welds, which are widely used in nuclear power plants, present major challenges for ultrasonic inspection due to the grain structure in the weld. Large grains in combination with the elastic anisotropy of the material lead to increased scattering and affect sound wave propagation in the weld. This results in a reduced signal-to-noise ratio, and complicates the interpretation of signals and the localization of defects. Mechanized ultrasonic inspection was applied to study austenitic stainless steel test blocks with different types of flaws, including inter-granular stress corrosion cracks (IGSCC). The results show that cracks located in the heat affected zone of the weld are easily detected when inspection from both sides of the weld is possible. In cases of limited accessibility, when ultrasonic inspection can be carried out only from one side of a weld, it may be difficult to distinguish between signals from scattering in the weld and signals from cracks.

Dugan, Sandra; Wagner, Sabine [Materials Testing Institute University of Stuttgart (MPA), Pfaffenwaldring 32, 70569 Stuttgart (Germany)

2014-02-18T23:59:59.000Z

6

Repair welding influence on offshore pipelines residual stress fields: An experimental study  

Science Journals Connector (OSTI)

Abstract Repair welds, are frequently used in steel structures either to remedy initial fabrication defects, or to rectify in-service degradations of the components. Some previous investigations indicated that repair welding is likely to pose adverse effects on the long-term integrity of the structure exposed to high pressure and temperature actions. It is believed that high residual stresses, associated with the repair process, most probably play an important role in many of subsequent failures. Repair welds might aggravate the size, magnitude and distribution of the tensile residual stresses in the weldments. These adversely affect the component structural integrity and remaining life. So far, no generally accepted guideline is available to provide reliable evaluations on the possible side effects from the repair welding in offshore oil/gas pipelines. This paper reports the result of residual stress measurement on single/double and partial/full repair welds in offshore pipelines. The semi destructive blind hole drilling and destructive sectioning methods have been employed to measure the residual stress fields in each case. In general, the results of the two measurement methods are in reasonable agreement. Residual stresses which are caused by full and partial repairs in the studied samples slightly increased the residual stress distribution when compared to the as-welded condition. Repetition of repair welding in same area influenced the residual stresses' magnitude and distribution especially in areas close to the weld centre line.

M. Zeinoddini; S. Arnavaz; A.P. Zandi; Y. Alizadeh Vaghasloo

2013-01-01T23:59:59.000Z

7

Effects of thermal aging on Stress Corrosion Cracking and mechanical properties of stainless steel weld metals  

E-Print Network [OSTI]

Stress Corrosion Cracking (SCC) in and around primary loop piping welds in Boiling Water Reactors has been observed worldwide as plants continue to operate at temperatures and pressures near 2880C (5500F) and 6.9 MPa (1000 ...

Hixon, Jeff

2006-01-01T23:59:59.000Z

8

The Effect of Weld Residual Stress on Life of Used Nuclear Fuel Dry Storage Canisters  

SciTech Connect (OSTI)

With the elimination of Yucca Mountain as the long-term storage facility for spent nuclear fuel in the United States, a number of other storage options are being explored. Currently, used fuel is stored in dry-storage cask systems constructed of steel and concrete. It is likely that used fuel will continue to be stored at existing open-air storage sites for up to 100 years. This raises the possibility that the storage casks will be exposed to a salt-containing environment for the duration of their time in interim storage. Austenitic stainless steels, which are used to construct the canisters, are susceptible to stress corrosion cracking (SCC) in chloride-containing environments if a continuous aqueous film can be maintained on the surface and the material is under stress. Because steel sensitization in the canister welds is typically avoided by avoiding post-weld heat treatments, high residual stresses are present in the welds. While the environment history will play a key role in establishing the chemical conditions for cracking, weld residual stresses will have a strong influence on both crack initiation and propagation. It is often assumed for modeling purposes that weld residual stresses are tensile, high and constant through the weld. However, due to the strong dependence of crack growth rate on stress, this assumption may be overly conservative. In particular, the residual stresses become negative (compressive) at certain points in the weld. The ultimate goal of this research project is to develop a probabilistic model with quantified uncertainties for SCC failure in the dry storage casks. In this paper, the results of a study of the residual stresses, and their postulated effects on SCC behavior, in actual canister welds are presented. Progress on the development of the model is reported.

Ronald G. Ballinger; Sara E. Ferry; Bradley P. Black; Sebastien P. Teysseyre

2013-08-01T23:59:59.000Z

9

Residual Stress Determination for A Ferritic Steel Weld Plate  

SciTech Connect (OSTI)

The primary objective of this experiment is to demonstrate the capability of neutron diffraction technique to reproducibly map residual strains in a ferritic steel weld. The objective includes the identification of corrections for variations in metal composition due to the welding process which produces changes in lattice parameter that are not due to mechanical effects. The second objective is to develop and demonstrate a best practice for neutron diffraction strain mapping of steel welds. The appropriate coordinate system for the measurement of a weld, which is strongly distorted from planar geometry, has to be defined. The coordinate system is important in determining the procedures for mounting and positioning of the weld so that mapping details, especially in regions of high gradients, can be conveniently inter-compared between laboratories.

Wang, D.-Q.; Hubbard, C.R.; Spooner, S.

1999-10-01T23:59:59.000Z

10

EFFECT OF UNBROKEN LIGAMENTS ON STRESS CORROSION CRACKING BEHAVIOR OF ALLOY 82H WELDS  

SciTech Connect (OSTI)

Previously reported stress corrosion cracking (SCC) rates for Alloy 82H gas-tungsten-arc welds tested in 360 C water showed tremendous variability. The excessive data scatter was attributed to the variations in microstructure, mechanical properties and residual stresses that are common in welds. In the current study, however, re-evaluation of the SCC data revealed that the large data scatter was an anomaly due to erroneous crack growth rates inferred from crack mouth opening displacement (CMOD) measurements. Apparently, CMOD measurements provided reasonably accurate SCC rates for some specimens, but grossly overestimated rates in others. The overprediction was associated with large unbroken ligaments that often form in welds in the wake of advancing crack fronts. When ligaments were particularly large, they prevented crack mouth deflection, so apparent crack incubation times (i.e. period of time before crack advance commences) based on CMOD measurements were unrealistically long. During the final states of testing, ligaments began to separate allowing the crack mouth to open rather quickly. This behavior was interpreted as a rapid crack advance, but it actually reflects the ligament separation rate, not the SCC rate. Revised crack growth rates obtained in this study exhibit substantially less scatter than that previously reported. The effects of crack orientation and fatigue flutter loading on SCC rates in 82H welds are also discussed.

Mills, W.J. and Brown, C.M.

2003-02-20T23:59:59.000Z

11

Stress Corrosion Cracking and Non-Destructive Examination of Dissimilar Metal Welds and Alloy 600  

SciTech Connect (OSTI)

The United States Nuclear Regulatory Commission (USNRC) has conducted research since 1977 in the areas of environmentally assisted cracking and assessment and reliability of non-destructive examination (NDE). Recent occurrences of cracking in Alloy 82/182 welds and Alloy 600 base metal at several domestic and overseas plants have raised several issues relating to both of these areas of NRC research. The occurrences of cracking were identified by the discovery of boric acid deposits resulting from through-wall cracking in the primary system pressure boundary. Analyses indicate that the cracking has occurred due to primary water stress corrosion cracking (PWSCC) in Alloy 82/182 welds. This cracking has occurred in two different locations: in hot leg nozzle-to-safe end welds and in control rod drive mechanism (CRDM) nozzle welds. The cracking associated with safe-end welds is important due to the potential for a large loss of reactor coolant inventory, and the cracking of CRDM nozzle base metal and welds, particularly circumferential cracking of CRDM nozzle base metal, is important due to the potential for a control rod to eject resulting in a loss of coolant accident. The industry response in the U.S. to this cracking is being coordinated through the Electric Power Research Institute's Materials Reliability Project (EPRI-MRP) in a comprehensive, multifaceted effort. Although the industry program is addressing many of the issues raised by these cracking occurrences, confirmatory research is necessary for the staff to evaluate the work conducted by industry groups. Several issues requiring additional consideration regarding the generic implications of these isolated events have been identified. This paper will discuss the recent events of significant cracking in domestic and foreign plants, discuss the limitations of NDE in detecting SCC, identify deficiencies in information available in this area, discuss the USNRC approach to address these issues, and discuss the development of an international cooperative effort. (authors)

Jackson, Deborah A. [U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001 (United States)

2002-07-01T23:59:59.000Z

12

MANAGING JOB LOSS and FINANCIAL STRESS  

E-Print Network [OSTI]

-hunting strategy. Put time and energy into planning actions that will lead to your next job such as preparingMANAGING JOB LOSS and FINANCIAL STRESS a Personal and Family Guide CENTER ON THE FAMILY #12;2 Managing Job Loss and Financial Stress The issues associated with losing one's job or having hours cut

13

Significance of changes in residual stresses and mechanical properties due to SMAW repair of girth welds in linepipe  

SciTech Connect (OSTI)

This program assessed the effects of SMAW repair welding on changes in surface residual stress distribution, fracture toughness and hardness around girth weld joints in linepipe. The following types of repair welds were studied: a part wall repair, a multiple part wall repair and full wall repair. The results were compared with a non-repaired weld sample. It was found that for the weld samples studied in this program, the full wall repair produced the most severe residual stress distribution followed by the multiple and single part wall repairs. The single repair only slightly increased the residual stress distribution when compared to the as-welded condition. Dramatic reductions in toughness were found in the multiple and full repairs due to coarse-grained regions produced during the repair operations. The single part wall repair exhibited an increase in toughness as a result of the addition of a cosmetic capping pass which resulted in greater grain refinement. This suggests that repair procedures utilizing a stringer or temper bead technique may reduce the effect of weld repairs on toughness.

McGaughy, T.; Boyles, L.

1990-10-31T23:59:59.000Z

14

Neutron and x-ray scattering studies of the metallurgical condition and residual stresses in Weldalite welds  

SciTech Connect (OSTI)

Weldalite is a lithium-containing aluminum alloy which is being considered for aerospace applications because its favorable strength-to-weight ratio. Successful welding of this alloy depends on the control of the metallurgical condition and residual stresses in the heat affected zone. Neutron and x-ray scattering methods of residual stress measurement were applied to plasma arc welds made in aluminum-lithium alloy test panels as part of an evaluation of materials for use in welded structures. In the course of these studies discrepancies between x-ray and neutron results from the heat affected zone (HAZ) of the weld were found. Texture changes and recovery from the cold work, indicated in peak widths, were found in the HAZ as well. The consideration of x-ray and neutron results leads to the conclusion that there is a change in solute composition which modifies the d-spacings in the HAZ which affects the neutron diffraction determination of residual stresses. The composition changes give the appearance of significant compressive strains in the HAZ. This effect and sharp gradients in the texture give severe anomalies in the neutron measurement of residual stress. The use of combined x-ray and neutron techniques and the solution to the minimizing of the neutron diffraction anomalies are discussed.

Spooner, S. [Oak Ridge National Lab., TN (United States); Pardue, E.B.S. [Technology for Energy Corp., Knoxville, TN (United States)

1995-12-31T23:59:59.000Z

15

On-Line Weld NDE with IR Thermography  

Broader source: Energy.gov (indexed) [DOE]

Weld cracks - Weld porosity Most critical Excessive indentation Stuck weld (insufficient fusion) Less critical Cracks Porosity 10 Managed by UT-Battelle for the Department of...

16

AN ULTRASONIC PHASED ARRAY EVALUATION OF INTERGRANULAR STRESS CORROSION CRACK (IGSCC) DETECTION IN AUSTENITIC STAINLESS STEEL PIPING WELDS  

SciTech Connect (OSTI)

Research is being conducted for the U.S. Nuclear Regulatory Commission at the Pacific Northwest National Laboratory to assess the effectiveness and reliability of advanced nondestructive examination (NDE) methods for the inspection of light water reactor (LWR) components and challenging material/component configurations. This study assessed the effectiveness of far-side inspections on wrought stainless steel piping with austenitic welds, as found in thin-walled, boiling water reactor (BWR) component configurations, for the detection and characterization of intergranular stress corrosion cracks (IGSCC).

Diaz, Aaron A.; Anderson, Michael T.; Cinson, Anthony D.; Crawford, Susan L.; Cumblidge, Stephen E.

2010-07-22T23:59:59.000Z

17

Sulfide stress cracking of a pipeline weld in sour gas service  

SciTech Connect (OSTI)

A replacement girth weld in a wet, sour gas gathering pipeline failed within 72 hours of start of operation. This paper describes the investigation of this unusual failure, indicates probable causes, and outlines potential changes in repair/replacement practices for wet, sour gas lines.

Szklarz, K.E.

1999-07-01T23:59:59.000Z

18

Ultrasonic measurement of the residual stresses in patch welded steel plates  

E-Print Network [OSTI]

, the simple and accurate method developed to measure the radiation patterns from these transducers also is presented. Differences in the ultrasonic travel times of the LCR wave were obtained in a stress relieved and a non-stress relieved 13 mm (1/2 in.) thick...

Junghans, Paul Gerard

2012-06-07T23:59:59.000Z

19

Neutron diffraction measurements of residual stresses in welds fabricated from highly anisotropic materials  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

neutron diffraction to neutron diffraction to engineering problems T.M. Holden Northern Stress Technologies Deep River, Ontario, Canada Oak Ridge National Laboratory, 13 nd June 2011 Reference material * "Introduction to the characterization of residual stress by neutron diffraction". M.T. Hutchings, P.J. Withers, T.M. Holden and T. Lorentzen, (Taylor and Francis: Boca Raton) 2005 * "Introduction to diffraction in Materials Science and Engineering", A.D. Krawitz (John Wiley and Sons ,Inc.: New York) 2001 * "Non-destructive testing-Standard Test Method for

20

ABSTRACT. The stress-relief cracking (SRC) susceptibility of single-pass welds  

E-Print Network [OSTI]

steel, HCM2S, has been evaluated and compared to 2.25Cr-1Mo steel using Gleeble thermal simulation and pressure vessels for chemical and fossil power plants. Many components in these power plants oper- ate techniques. HCM2S was found to be more susceptible to stress-relief cracking than 2.25Cr-1Mo steel. Simulated

DuPont, John N.

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Measurement and finite element analysis of temperature distribution in arc welding process  

Science Journals Connector (OSTI)

This presentation describes both the experimental measurement and finite element analysis used to study the temperature distribution during a metal inert gas (MIG) welding process, including the cooling down period. Welding was carried out on ... Keywords: FEA, MIG welding, arc welding, cracking, finite element analysis, metal inert gas welding, residual stress, simulation, temperature distribution, weldment temperature

C. K. Lee; J. Candy; C. P. H. Tan

2004-12-01T23:59:59.000Z

22

Weld Monitor  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Monitoring of Laser Beam Welding Monitoring of Laser Beam Welding Using Infrared Weld Emissions P. G. Sanders, J. S. Keske, G. Kornecki, and K. H. Leong Technology Development Division Argonne National Laboratory Argonne, IL 60439 USA The submitted manuscript has been authorized by a contractor of the U. S. Government under contract No. W-31-109-ENG-38. Accordingly, the U. S. Government retains a non-exclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U. S. Government purposes. Abstract A non-obtrusive, pre-aligned, solid-state device has been developed to monitor the primary infrared emissions during laser welding. The weld monitor output is a 100-1000 mV signal that depends on the beam power and weld characteristics. The DC level of this signal is related to weld

23

Remote sensing for site-specific management of biotic and abiotic stress in cotton  

E-Print Network [OSTI]

This study evaluated the applicability of remote sensing instrumentation for site- specific management of abiotic and biotic stress on cotton grown under a center pivot. Three different irrigation regimes (100%, 75%, and 50% ETc) were imposed on a...

Falkenberg, Nyland Ray

2004-09-30T23:59:59.000Z

24

On-Line Weld NDE with IR Thermography  

Broader source: Energy.gov (indexed) [DOE]

with gaps 17 Managed by UT-Battelle for the Department of Energy no weld Destructive measurement Post-weld signature Accomplishment: Actual Auto Body Parts 2T auto body structures...

25

WELDING RESEARCH -s55WELDING JOURNAL  

E-Print Network [OSTI]

WELDING RESEARCH -s55WELDING JOURNAL ABSTRACT. Dissimilar metal weld (DMW) failures between carbon corrosion conditions that require the use of austenitic stainless steels. A dissimi- lar metal weld (DMW to understand the mechanism of DMW failures in such applications. In the as-welded condition, a compo- sition

DuPont, John N.

26

Stress-wave energy management through material anisotropy Alireza V. Amirkhizi, Aref Tehranian, Sia Nemat-Nasser  

E-Print Network [OSTI]

Stress-wave energy management through material anisotropy Alireza V. Amirkhizi, Aref Tehranian, Sia that if this axis initially coincides with the stress-wave vector, then the energy of the plane waves would closely the required anisotropy, and to experimentally demonstrate the management of stress-wave energy in a desired

Nemat-Nasser, Sia

27

Influence of wet underwater welding on fracture values  

SciTech Connect (OSTI)

The fracture behavior of welds is influenced by residual stresses. The influence of residual stresses on fracture parameters is investigated through the comparison of wet underwater welds, dry welds and welds without residual stresses. The fracture parameters for a sharp, stationary crack on the surface of a bead on plate weld under bending are determined by the finite element method. The geometric influence of weld on fracture parameters is investigated. The stress intensity factor for linear elastic fracture mechanics, the J-integral and the crack tip opening displacement for plastic fracture mechanics are calculated. The material behavior is assumed as linear elastic or linear elastic/ideal plastic or elastic plastic with multilinear isotropic hardening. The numerical data are compared with the experiments.

Lindhorst, L.; Hamann, R.; Mahrenholtz, O. [Technical Univ. of Hamburg-Harburg, Hamburg (Germany). Offshore Engineering Section 2; Kocak, M. [GKSS Research Center, Geesthacht (Germany). Inst. of Material Research

1995-12-31T23:59:59.000Z

28

Laser Welding of Metals [Laser Applications Laboratory] - Nuclear  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Laser Welding of Metals Laser Welding of Metals Capabilities Engineering Experimentation Reactor Safety Experimentation Aerosol Experiments System Components Laser Applications Overview Laser Oil & Gas Well Drilling Laser Heat Treatment Laser Welding of Metals On-line Monitoring Laser Beam Delivery Laser Glazing of Railroad Rails High Power Laser Beam Delivery Decontamination and Decommissioning Refractory Alloy Welding Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Laser Applications Laboratory Laser Welding of Metals Project description: High-speed laser welding of metals. Category: Project with industrial partner (Delphi Energy and Engine Management Systems) Bookmark and Share

29

Management of Forests under Nutrient and Water Stress  

Science Journals Connector (OSTI)

Management of forest nutrition through fertilization and other forestry practices has, undoubtedly, helped to increase the productivity of forests. Relatively little attention has been given to the potential f...

E. K. Sadanandan Nambiar

1990-01-01T23:59:59.000Z

30

Management of forests under nutrient and water stress  

Science Journals Connector (OSTI)

Management of forest nutrition through fertilization and other forestry practices has, undoubtedly, helped to increase the productivity of forests. Relatively little attention has been given to the potential f...

E. K. Sadanandan Nambiar

31

WELDING RESEARCH -s51WELDING JOURNAL  

E-Print Network [OSTI]

mixed zone (PMZ) of dissimilar welds. Introduction Ferritic-to-austenitic dissimilar metal welds). Nickel-based filler metals are often used to prolong the life of austenitic-to- ferritic dissimilar welds to examine the gradient of alloying elements across the weld inter- face of austenitic/ferritic dissimilar

DuPont, John N.

32

WELDING RESEARCH -S125WELDING JOURNAL  

E-Print Network [OSTI]

cracking susceptibility of dissimilar metal welds between AL- 6XN super austenitic stainless steel and two and independent of weld metal dilution level, while the cracking suscepti- bility of welds produced with IN625 resistance of the weld metal. Previous research has shown that the depleted dendrite cores are susceptible

DuPont, John N.

33

Narrow gap laser welding  

DOE Patents [OSTI]

A laser welding process including: (a) using optical ray tracing to make a model of a laser beam and the geometry of a joint to be welded; (b) adjusting variables in the model to choose variables for use in making a laser weld; and (c) laser welding the joint to be welded using the chosen variables. 34 figs.

Milewski, J.O.; Sklar, E.

1998-06-02T23:59:59.000Z

34

Narrow gap laser welding  

DOE Patents [OSTI]

A laser welding process including: (a) using optical ray tracing to make a model of a laser beam and the geometry of a joint to be welded; (b) adjusting variables in the model to choose variables for use in making a laser weld; and (c) laser welding the joint to be welded using the chosen variables.

Milewski, John O. (Santa Fe, NM); Sklar, Edward (Santa Fe, NM)

1998-01-01T23:59:59.000Z

35

Examination of dissimilar metal welds in BWR and PWR piping  

SciTech Connect (OSTI)

This paper addresses dissimilar metal weld examinations at PWRS. Surveys were conducted to document the dissimilar metal weld configurations at PWR plants and to update the information known about dissimilar metal weld configurations at BWR plants. The experiences which BWR utilities have had with dissimilar metal weld examinations are documented and include: correct identification of IGSCC, indications thought to be IGSCC but were actually fabrication flaws, and difficulties encountered with the examination of dissimilar metal welds after stress improvement. An experimental program was conducted which verified that the longitudinal wave procedures developed for BWRs are also applicable to PWR designs.

MacDonald, D.E. [Electric Power Research Inst., Charlotte, NC (United States). NDE Center

1994-12-31T23:59:59.000Z

36

Design and fabrication of a stress-managed Nb3Sn wind and react dipole  

E-Print Network [OSTI]

A new approach to high-field dipole design is being developed at Texas A&M University. The goal of the development is to facilitate the use of high-field conductors (Nb3 and Bi-2212) and to manage Lorentz stress and magnetization so that field...

Noyes, Patrick Daniel

2007-09-17T23:59:59.000Z

37

WELDING RESEARCH -s77WELDING JOURNAL  

E-Print Network [OSTI]

to the changing microstructure from base metal to the weld zone, there are corresponding changes in hardness been performed on similar and dissimilar welds of aluminum alloys of the 1xxx, 2xxx, 5xxx, 6xxx, and 7- genic gas generated in arc welding by evaporation from the liquid pool and molten metal droplets (in

DuPont, John N.

38

Stress Management as an Enabling Technology for High-Field Superconducting Dipole Magnets  

E-Print Network [OSTI]

-Pounds HD High field Dipole HGQ High Gradient Quadrupole HQ High field Quadrupole HT Heat Treatment IC Critical Current IFCC Inter-Filament Coupling Currents ITER International Thermonuclear Experimental Reactor vi LARP LHC Accelerator... pressure impregnation (VPI) vessel using NbTi conductor [1, 2]. TAMU2 verified the heat treatment equipment and tested the stress management technology at low field using low Jc Nb3Sn conductor from the International Thermonuclear Experimental Reactor...

Holik, Eddie Frank

2014-06-03T23:59:59.000Z

39

WeldingFabr&MetalForm  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Welding, Welding, Fabrication, and Metal Forming Manufacturing Technologies The department consists of three trades: weld- ing; fabrication and assembly; and precision metal forming. These interrelated groups use similar equipment and rely on each other's skills. One stop will get you the service of three reliable trades. The team manufactures and assembles proto- type hardware and has the in-house capability of producing hardware with sizes ranging from thumbnail to rail-car. Expertise includes aircraft quality sheet metal construction, certified weld- ing, and assembly. The staff has experience managing a variety of activities: design modifi- cation assistance; in-house fabrication; and project management and can work with your engineers to transform sketches and ideas into working prototypes.

40

Fusion welding process  

DOE Patents [OSTI]

A process for the fusion welding of nickel alloy steel members wherein a ferrite containing pellet is inserted into a cavity in one member and melted by a welding torch. The resulting weld nugget, a fusion of the nickel containing alloy from the members to be welded and the pellet, has a composition which is sufficiently low in nickel content such that ferrite phases occur within the weld nugget, resulting in improved weld properties. The steel alloys encompassed also include alloys containing carbon and manganese, considered nickel equivalents.

Thomas, Kenneth C. (Export, PA); Jones, Eric D. (Salem, PA); McBride, Marvin A. (Hempfield Township, Westmoreland County, PA)

1983-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Test Results of a Nb3Sn Wind/React"Stress-Managed" Block Dipole  

SciTech Connect (OSTI)

A second phase of a high field dipole technology development has been tested. A Nb{sub 3}Sn block-coil model dipole was fabricated, using magnetic mirror geometry and wind/react coil technology. The primary objective of this phase was to make a first experimental test of the stress-management strategy pioneered at Texas A&M. In this strategy a high-strength support matrix is integrated with the windings to intercept Lorentz stress from the inner winding so that it does not accumulate in the outer winding. The magnet attained a field that was consistent with short sample limit on the first quench; there was no training. The decoupling of Lorentz stress between inner and outer windings was validated. In ramp rate studies the magnet exhibited a remarkable robustness in rapid ramping operation. It reached 85% of short sample(ss) current even while ramping 2-3 T/s. This robustness is attributed to the orientation of the Rutherford cables parallel to the field in the windings, instead of the transverse orientation that characterizes common dipole designs. Test results are presented and the next development phase plans are discussed.

McInturff, A.; Blackburn, R.; Diaczenko, N.; Elliott, T.; Henchel, W.; Jaisle, A.; McIntyre, P.; Noyes, P.; Sattarov, A.; Lietzke, A.; Hafalia Jr., R.; Lau, W.; Nyman, M.; Bish, P.

2007-06-01T23:59:59.000Z

42

WELDING RESEARCH -S249WELDING JOURNAL  

E-Print Network [OSTI]

thick that the reduction in the number of passes is dramatic, the time needed for additional positioning agent on the work- piece surface during gas tungsten arc welding to modify the flow in the weld pool mixtures of inorganic powders suspended in a volatile medium, for different materials. This method, re

Zhang, YuMing

43

Increasing Productivity of Welding  

E-Print Network [OSTI]

trend toward the continuous electrode wire pro e s cesses and away from shielded metal-arc welding dr stick welding as it is commonly called. The con tinuous electrode wire process include gas metal arc welding "GMAW", f lux-cored arc welding... versus the s shielded becomes more complex. However, for hi er strength materials, the gas shielded version is preferred, primarily because it can be used to the low alloy, high strength steels and will pr deposited weld metal closely approaching...

Uhrig, J. J.

1983-01-01T23:59:59.000Z

44

Method for welding beryllium  

DOE Patents [OSTI]

A method is provided for joining beryllium pieces which comprises: depositing aluminum alloy on at least one beryllium surface; contacting that beryllium surface with at least one other beryllium surface; and welding the aluminum alloy coated beryllium surfaces together. The aluminum alloy may be deposited on the beryllium using gas metal arc welding. The aluminum alloy coated beryllium surfaces may be subjected to elevated temperatures and pressures to reduce porosity before welding the pieces together. The aluminum alloy coated beryllium surfaces may be machined into a desired welding joint configuration before welding. The beryllium may be an alloy of beryllium or a beryllium compound. The aluminum alloy may comprise aluminum and silicon.

Dixon, Raymond D. (Los Alamos, NM); Smith, Frank M. (Espanola, NM); O'Leary, Richard F. (Los Alamos, NM)

1997-01-01T23:59:59.000Z

45

Caustic stress corrosion cracking of E-Brite and Carpenter 7-MO stainless steels welded to Nickel 200 and Inconel 600  

E-Print Network [OSTI]

CAUSTIC STRESS CORROSION CRACKING OF E-BRITE AND CARPENTER 7 MO STAINLESS STEELS NELDED TO NIC~~ 200 AND INCONEL 600 A Thesis STEVEN MILES STOCKt1AN Approved as to style and content by: Dr R, R? Griffin (ME) (Chairman of the Committee) Dr..., LE R. Cornwell (ME) (Committee Member) Dr? AD %olfe den (ME) (Committee Member) Dr T, CD Poll ck (EDG) (Committee Member) Dr, G? H Hopld. ns ( (Head of epartment) December 1962 ABSTRACT Caustic Stress Corrosion Cracking of E...

Stockman, Steven Miles

2012-06-07T23:59:59.000Z

46

Stress testing on silicon carbide electronic devices for prognostics and health management.  

SciTech Connect (OSTI)

Power conversion systems for energy storage and other distributed energy resource applications are among the drivers of the important role that power electronics plays in providing reliable electricity. Wide band gap semiconductors such as silicon carbide (SiC) and gallium nitride (GaN) will help increase the performance and efficiency of power electronic equipment while condition monitoring (CM) and prognostics and health management (PHM) will increase the operational availability of the equipment and thereby make it more cost effective. Voltage and/or temperature stress testing were performed on a number of SiC devices in order to accelerate failure modes and to identify measureable shifts in electrical characteristics which may provide early indication of those failures. Those shifts can be interpreted and modeled to provide prognostic signatures for use in CM and/or PHM. Such experiments will also lead to a deeper understanding of basic device physics and the degradation mechanisms behind failure.

Kaplar, Robert James; Brock, Reinhard C.; Marinella, Matthew; King, Michael Patrick; Smith, Mark A.; Atcitty, Stanley

2011-01-01T23:59:59.000Z

47

Test Results of a Nb3Sn Wind/React 'Stress-Managed' BlockDipole  

SciTech Connect (OSTI)

A second phase of a highfield dipole technology developmenthas been tested. A Nb3Sn block-coil model dipole was fabricated, usingmagnetic mirror geometry and wind/react coil technology. The primaryobjective of this phase was to make a first experimental test of thestress-management strategy pioneered at Texas A&M. In this strategy ahigh-strength support matrix is integrated with the windings to interceptLorentz stress from the inner winding so that it does not accumulate inthe outer winding. The magnet attained a field that was consistent withshort sample limit on the first quench; there was no training. Thedecoupling of Lorentz stress between inner and outer windings wasvalidated. In ramp rate studies the magnet exhibited a remarkablerobustness in rapid ramping operation. It reached 85 percent of shortsample(ss) current even while ramping 2-3 T/s. This robustness isattributed to the orientation of the Rutherford cables parallel to thefield in the windings, instead of the transverse orientation thatcharacterizes common dipole designs. Test results are presented and thenext development phase plans are discussed.

McInturff, A.; Bish, P.; Blackburn, R.; Diaczenko, N.; Elliott,T.; Hafalia Jr., R.; Henchel, W.; Jaisle, A.; Lau, W.; Lietzke, A.; McIntyre, P.; Noyes, P.; Nyman, M.; Sattarov, A.; Sattarov, A.

2006-08-25T23:59:59.000Z

48

On-Line Weld NDE with IR Thermography  

Broader source: Energy.gov (indexed) [DOE]

advisory committee in the order of importance (high to low) - Weld with no or minimal fusion - Cold or stuck weld - Weld nugget size - Weld expulsion and indentation - Weld...

49

L3 Milestone Use Computational Model to Design and Optimize Welding Conditions to Suppress Helium  

Broader source: Energy.gov (indexed) [DOE]

L3 Milestone L3 Milestone Use Computational Model to Design and Optimize Welding Conditions to Suppress Helium Cracking during Welding June 2012 Wei Zhang and Zhili Feng, ORNL Eric Willis, EPRI Background and Objectives Today, welding is widely used for repair, maintenance and upgrade of nuclear reactor components. As a critical technology to extend the service life of nuclear power plants beyond 60 years, weld technology must be further developed to meet new challenges associated with the aging of the plants, such as control and mitigation of the detrimental effects of weld residual stresses and repair of highly irradiated materials. To meet this goal, fundamental understanding of the "welding" effect is necessary for development of new and improved welding technologies.

50

Marangoni effects in welding  

Science Journals Connector (OSTI)

...problem of it variable weld penetration or cast-to-cast variation...etration in HS casts and reduced penetration in LS casts. Although this...travel speed (Sw) affects the rate of heat input to the weld...energy resulted in increased penetration for HS and MS casts but have...

1998-01-01T23:59:59.000Z

51

CHARACTERIZATION OF DEFECTS IN ALLOY 152, 52 AND 52M WELDS  

SciTech Connect (OSTI)

Defect distributions have been documented by optical metallography, scanning electron microscopy and electron backscatter diffraction in alloy 152 and 52 mockups welds, alloy 52 and 52M overlay mockups and an alloy 52M inlay. Primary defects were small cracks at grain boundaries except for more extensive cracking in the dilution zone of an alloy 52 overlay on 304SS. Detailed characterizations of the dilution zone cracks were performed by analytical transmission electron microscopy identifying grain boundary titanium-nitride precipitation associated with the intergranular separations. I. INTRODUCTION Weldments continue to be a primary location of stress-corrosion cracking (SCC) in light-water reactor systems. While problems related to heat-affected-zone (HAZ) sensitization and intergranular (IG) SCC of austenitic stainless alloys in boiling-water reactors (BWRs) have been significantly reduced, SCC has now been observed in HAZs of non-sensitized materials and in dissimilar metal welds where Ni-base alloy weld metals are used. IGSCC in weld metals has been observed in both BWRs and pressurized water reactors (PWRs) with recent examples for PWR pressure vessel penetrations producing the most concern. This has led to the replacement of alloy 600/182/82 welds with higher Cr, more corrosion-resistant replacement materials (alloy 690/152/52/52M). Complicating this issue has been a known susceptibility to cracking during welding [1-7] of these weld metals. There is a critical need for an improved understanding of the weld metal metallurgy and defect formation in Ni-base alloy welds to effectively assess long-term performance. A series of macroscopic to microscopic examinations were performed on available mockup welds made with alloy 52 or alloy 152 plus selected overlay and inlay mockups. The intent was to expand our understanding of weld metal structures in simulated LWR service components with a focus on as-welded defects. Microstructural features, defect distributions, defect characteristics and weld residual strains were examined by optical metallography, scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy. Industry-supplied mock-up welds were characterized including alloy 52 and 152 weldments, alloy 52M overlay and inlay welds, and an alloy 52 overlay. II. WELDMENTS II.A. Alloy 52 and 152 Weld Mockups The alloy 52 and 152 weld mockups were fabricated by MHI for the Kewaunee reactor and were obtained from the EPRI NDE Center. The mockups were U-groove welds joining two plates of 304SS as shown in Figure 1. Alloy 152 butter (heat 307380) was placed on the U-groove surface for both mockups by shielded metal arc welding (SMAW). For the alloy 152 weld mockup, the alloy 152 fill (heat 307380) was also applied using SMAW while for the alloy 52 weld mockup, the alloy 52 fill (heat NX2686JK) was applied using gas tungsten arc welding (GTAW). Welding parameters for the fill materials were substantially different with the alloy 152 SMAW having a deposition speed of 4-25 cm/min with a current of 95-145 A and the alloy 52 GTAW having a deposition speed of 4-10 cm/min with a current of 150-300 A. One prominent feature in these mockup welds is the presence of a crack starting at the 304SS butt joint at the bottom of the U-groove and extending up into the weld. It appears that the 304SS plate on either side of the butt joint acted as an anchor for the weld resulting in a stress rise across the slit that drove crack formation and extension up into the fill weld. As will be shown in the next section, the extent of the cracking around this stress riser was much greater in the MHI 52 weld mockup.

Bruemmer, Stephen M.; Toloczko, Mychailo B.; Olszta, Matthew J.; Seffens, Rob J.; Efsing, Pal G.

2009-08-27T23:59:59.000Z

52

Prediction of Weld Penetration in FCAW of HSLA steel using Artificial Neural Networks  

SciTech Connect (OSTI)

Flux-cored arc welding (FCAW) is a semiautomatic or automatic arc welding process that requires a continuously-fed consumable tubular electrode containing a flux. The main FCAW process parameters affecting the depth of penetration are welding current, arc voltage, nozzle-to-work distance, torch angle and welding speed. Shallow depth of penetration may contribute to failure of a welded structure since penetration determines the stress-carrying capacity of a welded joint. To avoid such occurrences; the welding process parameters influencing the weld penetration must be properly selected to obtain an acceptable weld penetration and hence a high quality joint. Artificial neural networks (ANN), also called neural networks (NN), are computational models used to express complex non-linear relationships between input and output data. In this paper, artificial neural network (ANN) method is used to predict the effects of welding current, arc voltage, nozzle-to-work distance, torch angle and welding speed on weld penetration depth in gas shielded FCAW of a grade of high strength low alloy steel. 32 experimental runs were carried out using the bead-on-plate welding technique. Weld penetrations were measured and on the basis of these 32 sets of experimental data, a feed-forward back-propagation neural network was created. 28 sets of the experiments were used as the training data and the remaining 4 sets were used for the testing phase of the network. The ANN has one hidden layer with eight neurons and is trained after 840 iterations. The comparison between the experimental results and ANN results showed that the trained network could predict the effects of the FCAW process parameters on weld penetration adequately.

Asl, Y. Dadgar; Mostafa, N. B.; Panahizadeh, V. R. [Department of Mechanical Engineering, Shahid Rajaee Teacher Training University, Tehran (Iran, Islamic Republic of); Seyedkashi, S. M. H. [Department of Mechanical Engineering, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

2011-01-17T23:59:59.000Z

53

A comparison of LBW and GTAW processes in miniature closure welds  

SciTech Connect (OSTI)

When small electronic components with glass-to-metal seals are closure welded, residual stresses developed in the glass are of concern. If these stresses exceed allowable tensile levels` the resulting weld-induced seal failure may cause the entire component to be scrapped or reworked at substantial cost. Conventional wisdom says the best welding process for these applications is that which provides the least heat input, and that Laser Beam Welding (LBW) provides less heat input than Gas Tungsten Arc Welding. (GTAW); however, other concerns such as weld fit-up, part variability, and material weldability can modify the final choice of a welding process. In this paper we compare the characteristic levels of heat input and the residual stresses generated in the glass seals for the two processes (as calculated by 3D Finite Element Analysis) as a function of heat input and travel speed, and contrast some of the other manufacturing decisions that must be made to choose a production process. The geometry chosen is a standing edge corner weld in a cylindrical container about 20 mm diameter by 35 mm tall. Four metal pins are glassed into the part lid. The stresses calculated to result from continuous wave C0{sub 2} LBW are compared with those that result from GTAW. The total energy required by the laser weld is significantly less than for the equivalent size GTA weld. The energy input required for a given size weld is inversely proportional to the travel speed, but approaches a saturation level as the travel speed increases. LBW travel speeds ranging from 10 mm/sec to 50 mm/sec were examined.

Knorovsky, G.A.; Fuerschbach, P.W.; Gianoulakis, S.E.; Burchett, S.N.

1995-07-01T23:59:59.000Z

54

Friction stir welding tool  

DOE Patents [OSTI]

A friction stir welding tool is described and which includes a shank portion; a shoulder portion which is releasably engageable with the shank portion; and a pin which is releasably engageable with the shoulder portion.

Tolle, Charles R. (Idaho Falls, ID); Clark, Denis E. (Idaho Falls, ID); Barnes, Timothy A. (Ammon, ID)

2008-04-15T23:59:59.000Z

55

Implications of changes in the post-weld heat treatment requirements on properties of steels and welds for offshore structures  

SciTech Connect (OSTI)

The reductions in the post-weld heat treatment temperatures and hold times proposed in revisions to pressure vessel (BS5500) and offshore steel (EN 10225) codes are considered in relation to their effects on resistance to fracture initiation. A review of the effects of the proposed changes on the mechanical properties and residual stresses in medium strength C-Mn steels and welds is described. It is concluded that the proposed reductions in temperature and hold time will, in general, minimize the changes in mechanical properties which would occur under current PWHT procedures. However, the levels of residual stresses will be significantly higher, and this will reduce the margin against fracture initiation.

Pisarski, H.G. [TWI, Cambridge (United Kingdom). Structural Integrity Dept.

1996-12-01T23:59:59.000Z

56

Corrosion Resistant Cladding by YAG Laser Welding in Underwater Environment  

SciTech Connect (OSTI)

It is known that stress-corrosion cracking (SCC) will occur in nickel-base alloys used in Reactor Pressure Vessel (RPV) and Internals of nuclear power plants. A SCC sensitivity has been evaluated by IHI in each part of RPV and Internals. There are several water level instrumentation nozzles installed in domestic BWR RPV. In water level instrumentation nozzles, 182 type nickel-base alloys were used for the welding joint to RPV. It is estimated the SCC potential is high in this joint because of a higher residual stress than the yield strength (about 400 MPa). This report will describe a preventive maintenance method to these nozzles Heat Affected Zone (HAZ) and welds by a corrosion resistant cladding (CRC) by YAG Laser in underwater environment (without draining a reactor water). There are many kinds of countermeasures for SCC, for example, Induction Heating Stress Improvement (IHSI), Mechanical Stress Improvement Process (MSIP) and so on. A YAG laser CRC is one of them. In this technology a laser beam is used for heat source and irradiated through an optical fiber to a base metal and SCC resistant material is used for welding wires. After cladding the HAZ and welds are coated by the corrosion resistant materials so their surfaces are improved. A CRC by gas tungsten arc welding (GTAW) in an air environment had been developed and already applied to a couple of operating plants (16 Nozzles). This method was of course good but it spent much time to perform because of an installation of some water-proof working boxes to make a TIG-weldability environment. CRC by YAG laser welding in underwater environment has superior features comparing to this conventional TIG method as follows. At the viewpoint of underwater environment, (1) an outage term reduction (no drainage water). (2) a radioactive exposure dose reduction for personnel. At that of YAG laser welding, (1) A narrower HAZ. (2) A smaller distortion. (3) A few cladding layers. A YAG laser CRC test in underwater environment was carried out in the different welding position, horizontal, vertical upward and downward. The soundness of cladding layers (about 3 mm) is confirmed in visual and penetration test, and cross section observation. In the application to the actual plants, it is preferable to reduce the start and end point numbers of beads with which a defect is easy to cause. Therefore a special welding equipment for a YAG laser CRC that could weld continuously was developed. (authors)

Tsutomi Kochi; Toshio Kojima; Suemi Hirata; Ichiro Morita; Katsura Ohwaki [Ishikawajima-Harima Heavy Industries Company Ltd., 1 Shin-Nakaharacho, Isogoku, Yokohama 235-8501 (Japan)

2002-07-01T23:59:59.000Z

57

Concurrent ultrasonic weld evaluation system  

DOE Patents [OSTI]

A system for concurrent, non-destructive evaluation of partially completed welds for use in conjunction with an automated welder is disclosed. The system utilizes real time, automated ultrasonic inspection of a welding operation as the welds are being made by providing a transducer which follows a short distance behind the welding head. Reflected ultrasonic signals are analyzed utilizing computer based digital pattern recognition techniques to discriminate between good and flawed welds on a pass by pass basis. The system also distinguishes between types of weld flaws. 5 figs.

Hood, D.W.; Johnson, J.A.; Smartt, H.B.

1987-12-15T23:59:59.000Z

58

Fracture mechanics analysis on the resistance of welded details under variable amplitude long life loading  

E-Print Network [OSTI]

Fracture mechanics approach has been used to analyze the behavior of fatigue resistance of welded details existing in highway steel bridges under variable amplitude long life loading which means most of the stress ranges will be below constant...

Zhou, Minjian

1993-01-01T23:59:59.000Z

59

Certification of a weld produced by friction stir welding  

DOE Patents [OSTI]

Methods, devices, and systems for providing certification of friction stir welds are disclosed. A sensor is used to collect information related to a friction stir weld. Data from the sensor is compared to threshold values provided by an extrinsic standard setting organizations using a certification engine. The certification engine subsequently produces a report on the certification status of the weld.

Obaditch, Chris; Grant, Glenn J

2013-10-01T23:59:59.000Z

60

Robotic Welding and Inspection System  

SciTech Connect (OSTI)

This paper presents a robotic system for GTA welding of lids on cylindrical vessels. The system consists of an articulated robot arm, a rotating positioner, end effectors for welding, grinding, ultrasonic and eddy current inspection. Features include weld viewing cameras, modular software, and text-based procedural files for process and motion trajectories.

H. B. Smartt; D. P. Pace; E. D. Larsen; T. R. McJunkin; C. I. Nichol; D. E. Clark; K. L. Skinner; M. L. Clark; T. G. Kaser; C. R. Tolle

2008-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Dissimilar-weld failure analysis and development program. Volume 1. Executive summary. Final report  

SciTech Connect (OSTI)

Failure of dissimilar metal welds is a major cause of forced outage in fossil boilers. A research project was carried out to: Develop a clearer understanding of the underlying causes of dissimilar weld failures; develop a methodology for estimating the residual life of service welds; develop a critical discriminatory test to predict the relative performance of welds; and develop guidelines for improved-performance dissimilar welds. The research methodology included review of prior experience as well as evaluation of a large number of failed and unfailed welds obtained from boiler superheaters or reheaters. The evaluations included metallography, mechanical testing and boiler inspections; in many cases, tube loading histories at the dissimilar weld locations were estimated. This work resulted in a clearer understanding of the root cause of weld failures. Furthermore, a quantitative relationship was derived between failure susceptibility and weld metal ''system'' loads, cycles, and temperatures (all critical parameters in weld performance). Accelerated discriminatory tests, including a number of geometries and modes of stressing and thermal cycling, were examined. The shortest time to failure, good reproducibility, and the capability to control loads and monitor cracking were achieved in a test which involved applying four-point bending loads to internally pressurized full-size tubular specimens. Tests at 593/sup 0/C (1100/sup 0/F), which involved temperature cycling, had failure times of only 400 h for stainless-steel fillers and 1500 h for nickel-base fillers. Guidelines for improved welds were derived from all the program results. They include and offer guidance on the considerations of weld-filler selection, weld geometry, heat treatment, etc., in relation to expected service conditions and on locating DMWs to optimize service performance. 7 refs., 18 figs., 3 tabs.

Not Available

1985-11-01T23:59:59.000Z

62

Friction stir welding tool and process for welding dissimilar materials  

DOE Patents [OSTI]

A friction stir welding tool and process for lap welding dissimilar materials are detailed. The invention includes a cutter scribe that penetrates and extrudes a first material of a lap weld stack to a preselected depth and further cuts a second material to provide a beneficial geometry defined by a plurality of mechanically interlocking features. The tool backfills the interlocking features generating a lap weld across the length of the interface between the dissimilar materials that enhances the shear strength of the lap weld.

Hovanski, Yuri; Grant, Glenn J; Jana, Saumyadeep; Mattlin, Karl F

2013-05-07T23:59:59.000Z

63

Weld seam tracking and lap weld penetration monitoring using the optical spectrum of the weld plume  

SciTech Connect (OSTI)

Joining of dissimilar materials is a long standing problem in manufacturing, with many tricks and special techniques developed to successfully join specific pairs of materials. Often, these special techniques impose stringent requirements on the process such as precise control of process parameters to achieve the desired joint characteristics. Laser welding is one of the techniques which has had some success in welding dissimilar metal alloys, and appears to be a viable process for these materials. Minimal heat input limits differential thermal expansion, and the small weld pool allows precise control of alloy mixing in the fusion zone. Obtaining optimal weld performance requires accurate monitoring and control of absorbed laser power and weld focus position. In order to monitor the laser welding process, the authors have used a small computer controlled optical spectrometer to observe the emission from the weld plume. Absorbed laser power can be related to the temperature of the weld pool surface and the plume above the weld. Focus position relative to the joint can easily be seen by the proportion of elements from each material existing in the plume. This monitor has been used to observe and optimize the performance of butt and lap welds between dissimilar alloys, where each alloy contains at least one element not found in the other alloy. Results will be presented for a copper-steel butt joint and a lap weld between stainless and low alloy steels.

Mueller, R.E. [Univ. of Waterloo, Ontario (Canada); Hopkins, J.A.; Semak, V.V.; McCay, M.H. [Univ. of Tennessee, Tullahoma, TN (United States)

1996-12-31T23:59:59.000Z

64

MAIN APPLICATIONS Spot welding  

E-Print Network [OSTI]

IRB 6400 MAIN APPLICATIONS Spot welding Press tending Material handling Machine tending Palletizing with high material strength. The arms are mechanically balanced and equipped with double bearings. Advanced DATA, IRB 6400 INDUSTRIAL ROBOT WORKING RANGE AND LOAD DIAGRAM IRB 6400PE IRB 6400R IRB 6400S PR10036EN

De Luca, Alessandro

65

3013 DE INNER CONTAINER CLOSURE WELD CORROSION EVALUATION  

SciTech Connect (OSTI)

Destructive evaluation (DE) of 3013 containers is one part of the U. S. Department of Energy Integrated Surveillance Program. During standard DE of 3013 containers, visual examinations for pitting and stress corrosion cracking (SCC) are performed on the accessible surfaces of the outer, inner, and convenience containers, which make up the 3013 container. As a result of 3013 DE additional analysis, the area near the inner container closure weld has been identified as being a region of increased corrosion susceptibility, which may provide a pathway for corrosive gases to the outer container. This area has a higher residual stress, an altered microstructure, and less corrosion resistant weld oxides as a result of the welding process as well as a lower temperature than other areas of the container, which may increase the absorption of moisture on the surface. The deposition of moisture in this stressed region could lead to pitting and stress corrosion cracking. During FY2013, the inner container closure weld area was more closely evaluated on several archived samples from DE containers. These containers included FY09 DE2, FY12 DE4, FY12 DE6 and FY12 DE7 and the Hanford High Moisture Container. The additional examinations included visual observations with a stereomicroscope, scanning electron microscopy along with energy dispersive spectroscopy for chemical analysis, and serial metallography of the sidewall and lid that are part of the inner container closure weld region. Pitting was observed in all the samples taken from the closure weld regions of the examined inner containers. This pitting was generally less 20 μm with most less than 5m. These pits were similar in depth to those observed in the vapor exposed surfaces of teardrops in the shelf life corrosion testing. Cracking was not observed on either the vapor-exposed surfaces of the teardrop coupons or the inner container closure weld region. Further testing is necessary to determine if the conditions in the welded inner container could support SCC during the 50 year life time for the 3013 container.

Mickalonis, J.

2013-09-30T23:59:59.000Z

66

A comparative evaluation of low-cycle fatigue behavior of type 316LN base metal, 316 weld metal, and 316LN/316 weld joint  

SciTech Connect (OSTI)

A comparative evaluation of the low-cycle fatigue (LCF) behavior of type 316LN base metal, carried out at 773 and 873 K. Total strain-controlled LCF tests were conducted at a constant strain rate of 3 {times} 10{sup {minus}3} s{sup {minus}1} with strain amplitudes in the range {+-}0.20 to {+-}1.0 pct. Weld pads with single V and double V configuration were prepared by the shielded metal-arc welding (SMAW) process using 316 electrodes for weld-metal and weld-joint specimens. Optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) of the untested and tested samples were carried out to elucidate the deformation and the fracture behavior. The cyclic stress response of the base metal shows a very rapid hardening to a maximum stress followed by a saturated stress response. Weld metal undergoes a relatively short initial hardening followed by a gradual softening regime. Weld joints exhibit an initial hardening and a subsequent softening regime at all strain amplitudes, except at low strain amplitudes where a saturation regime is noticed. The initial hardening observed in base metal has been attributed to interaction between dislocations and solute atoms/complexes and cyclic saturation to saturation in the number density of slip bands. The 18-8 group of austenitic stainless steels, such as AISI type 316, 304, and their modified grades, finds applications as structural material for various components of the liquid-metal-cooled fast breeder reactor (LMFBR).

Valsan, M.; Sundararaman, D.; Sankara Rao, K.B.; Mannan, S.L. [Indira Gandhi Centre for Atomic Research, Tamil Nadu (India)

1995-05-01T23:59:59.000Z

67

Modeling of the moving induction heating used as secondary heat source in weld-based additive manufacturing  

Science Journals Connector (OSTI)

To combat thermal-induced problems such as residual stress, deformation, and crack, induction heating is introduced into weld-based additive manufacturing process as a controlled thermal intervention. To ... nume...

Xingwang Bai; Haiou Zhang; Guilan Wang

2014-10-01T23:59:59.000Z

68

New findings in welding of structural steels  

Science Journals Connector (OSTI)

Gas shielded arc welding is the most widely applied welding process in industry. H2 (1.0425) structural steel chosen can be welded very cost-effectively with VAC 60 welding wires in CO2 shielding gas. With only the replacement of a highly oxidising gas, i.e. CO2, with a less oxidising gas mixture, i.e. Ar+18% CO2, a nicer appearance of the weld face and a higher weld quality may be obtained. Still higher quality of welds may be accomplished by employing pulsed arc welding of structural steels. In the study and development of the existing welding process, special attention was paid to the metal transfer. In pulsed arc welding with VAC 60 wire in the protective gas mixture of Ar+18% CO2, the metal transfer is very smooth and uniform in a very wide range of welding parameters. Because of the low oxidising capability of the Ar+18% CO2 gas mixture and the very short time of droplet formation, however, in pulsed arc welding major chemical processes in the droplet will occur only in welding with a higher average welding current (281 A). Less alloyed surfacing welds with silicon and manganese will provide higher quality only because of the surfacing weld dilution resulting from the parent-metal fusion, i.e. penetration. In pulsed arc welding, a pulse shape and energy and base current may efficiently affect the degree of penetration.

Uros Kejzar; Rajko Kejzar; Janez Grum; Damjan Klobcar

2007-01-01T23:59:59.000Z

69

Narrow groove welding gas diffuser assembly and welding torch  

DOE Patents [OSTI]

A diffuser assembly is provided for narrow groove welding using an automatic gas tungsten arc welding torch. The diffuser assembly includes a manifold adapted for adjustable mounting on the welding torch which is received in a central opening in the manifold. Laterally extending manifold sections communicate with a shield gas inlet such that shield gas supplied to the inlet passes to gas passages of the manifold sections. First and second tapered diffusers are respectively connected to the manifold sections in fluid communication with the gas passages thereof. The diffusers extend downwardly along the torch electrode on opposite sides thereof so as to release shield gas along the length of the electrode and at the distal tip of the electrode. The diffusers are of a transverse width which is on the order of the thickness of the electrode so that the diffusers can, in use, be inserted into a narrow welding groove before and after the electrode in the direction of the weld operation.

Rooney, Stephen J. (East Berne, NY)

2001-01-01T23:59:59.000Z

70

Resistance Spot Welding of Galvanized Steel: Part II. Mechanisms of Spot Weld Nugget Formation  

E-Print Network [OSTI]

of material variations and weld process parameter modifications on resistance spot welding of coated( l Resistance Spot Welding of Galvanized Steel: Part II. Mechanisms of Spot Weld Nugget Formation S. A. GEDEON and T. W. EAGAR Dynamic inspection monitoring of the weld current, voltage, resistance

Eagar, Thomas W.

71

Dissimilar-weld failure analysis and development. Comparative behavior of similar and dissimilar welds. Final report. [Welds of 2-1/4Cr-1Mo to 2-1/4Cr-1Mo using 2-1/4Cr-1Mo filler material; and austenitic to ferritic steel welds made by fusion welding alloy-800H to 2-1/4Cr-1Mo using nickel base filler metal ERNiCr-3  

SciTech Connect (OSTI)

The 593/sup 0/C (1100/sup 0/F) stress rupture behavior of similar metal welds (SMWs) and dissimilar metal welds (DMWs) was investigated under cyclic load and cyclic temperature conditions to provide insight into the question, ''Why do DMWs fail sooner than SMWs in the fossil fuel boilers.'' The weld joints of interest were an all ferritic steel SMW made by fusion welding 2-1/4Cr-1Mo to 2-1/4Cr-1Mo using 2-1/4Cr-1Mo filler metal and an austenitic to ferritic steel DMW made by fusion welding Alloy-800H to 2-1/4Cr-1Mo using a nickel base filler metal ERNiCr-3. The stress rupture behavior obtained on cross weld specimens was similar for both types of welds with only a 20% reduction in rupture life for the DMW. For rupture times less than 1500 hours, failures occurred in the 2-1/4Cr-1Mo base metal whereas, for rupture times greater than 1500 hours, failures occurred in the 2-1/4Cr-1Mo heat affected zone (HAZ). The HAZ failures exhibited a more brittle appearance than the base metal failures for both types of welds and it appears that the life of both joints was limited by the stress rupture properties of the HAZ. These results support the hypothesis that increased residual stresses due to abrupt changes in hardness (strength) of metals involved are the major contributors to the reduction in life of DMWs as compared to SMWs. 10 refs., 15 figs., 7 tabs.

Busboom, H.; Ring, P.J.

1986-07-01T23:59:59.000Z

72

Laser Welding of Aluminum and Aluminum Alloys  

E-Print Network [OSTI]

.. ) Laser Welding of Aluminum and Aluminum Alloys Welds made with sharp bevel-groove weld aluminum and by aluminum alloy 5456 have been studied. The results indicate that initial absorption varies of the most dramatic illustrations of the differences in beam characteristics occurs when welding aluminum

Eagar, Thomas W.

73

Residual Stresses in Weldments by Neutron Diffraction  

E-Print Network [OSTI]

Residual Stresses in Weldments by Neutron Diffraction Shanmukha Rao M, Jon James, Shirley Northover :- The neutron diffraction is determined from Bragg's law. When neutron propagate through crystal sample, Coherent, Incoherent and Absorption Scattering phenomena take place Weld MaterialsPlate materials Stress

Bandara, Arosha

74

Assisting manual welding with robot  

Science Journals Connector (OSTI)

This paper presents a first attempt to assist manual welding with a physically interactive robot. An interactive control scheme is developed to suppress the vibrations of torch during the welding of novice welders. The torch is attached to the end-effector of a haptic-robot. Human and robot act together on the welding torch: the human controls the direction and speed; the robot suppresses the sudden and abrupt motions. The control scheme is developed by experimenting with an air-paint-brush. The painting process emulates the actual welding. Such an emulating environment is useful to surmount the difficulties of experimentation with actual welding. The impedance parameters of the control scheme are investigated. A damping value is determined for an effective vibration suppression and minimum human effort. A variable impedance control scheme is applied to ease the manipulation of the torch while not welding. The results of real welding of novice welders with and without robot assistance are presented. There is a considerable improvement in the performance of the welders when they are assisted with the robot.

Mustafa Suphi Erden; Bobby Mari?

2011-01-01T23:59:59.000Z

75

Pulse shaping effects on weld porosity in laser beam spot welds : contrast of long- & short- pulse welds.  

SciTech Connect (OSTI)

Weld porosity is being investigated for long-pulse spot welds produced by high power continuous output lasers. Short-pulse spot welds (made with a pulsed laser system) are also being studied but to a much small extent. Given that weld area of a spot weld is commensurate with weld strength, the loss of weld area due to an undefined or unexpected pore results in undefined or unexpected loss in strength. For this reason, a better understanding of spot weld porosity is sought. Long-pulse spot welds are defined and limited by the slow shutter speed of most high output power continuous lasers. Continuous lasers typically ramp up to a simmer power before reaching the high power needed to produce the desired weld. A post-pulse ramp down time is usually present as well. The result is a pulse length tenths of a second long as oppose to the typical millisecond regime of the short-pulse pulsed laser. This study will employ a Lumonics JK802 Nd:YAG laser with Super Modulation pulse shaping capability and a Lasag SLS C16 40 W pulsed Nd:YAG laser. Pulse shaping will include square wave modulation of various peak powers for long-pulse welds and square (or top hat) and constant ramp down pulses for short-pulse welds. Characterization of weld porosity will be performed for both pulse welding methods.

Ellison, Chad M. (Honeywell FM& T, Kansas City, MO); Perricone, Matthew J. (R.J. Lee Group, Inc., Monroeville, PA); Faraone, Kevin M. (BWX Technologies, Inc., Lynchburg, VA); Norris, Jerome T.

2007-10-01T23:59:59.000Z

76

ADVANCED INTEGRATION OF MULTI-SCALE MECHANICS AND WELDING PROCESS SIMULATION IN WELD INTEGRITY ASSESSMENT  

SciTech Connect (OSTI)

The potential to save trillions of BTUs in energy usage and billions of dollars in cost on an annual basis based on use of higher strength steel in major oil and gas transmission pipeline construction is a compelling opportunity recognized by both the US Department of Energy (DOE). The use of high-strength steels (X100) is expected to result in energy savings across the spectrum, from manufacturing the pipe to transportation and fabrication, including welding of line pipe. Elementary examples of energy savings include more the 25 trillion BTUs saved annually based on lower energy costs to produce the thinner-walled high-strength steel pipe, with the potential for the US part of the Alaskan pipeline alone saving more than 7 trillion BTU in production and much more in transportation and assembling. Annual production, maintenance and installation of just US domestic transmission pipeline is likely to save 5 to 10 times this amount based on current planned and anticipated expansions of oil and gas lines in North America. Among the most important conclusions from these studies were: While computational weld models to predict residual stress and distortions are well-established and accurate, related microstructure models need improvement. Fracture Initiation Transition Temperature (FITT) Master Curve properly predicts surface-cracked pipe brittle-to-ductile initiation temperature. It has value in developing Codes and Standards to better correlate full-scale behavior from either CTOD or Charpy test results with the proper temperature shifts from the FITT master curve method. For stress-based flaw evaluation criteria, the new circumferentially cracked pipe limit-load solution in the 2007 API 1104 Appendix A approach is overly conservative by a factor of 4/?, which has additional implications. . For strain-based design of girth weld defects, the hoop stress effect is the most significant parameter impacting CTOD-driving force and can increase the crack-driving force by a factor of 2 depending on strain-hardening, pressure level as a % of SMYS, and flaw size. From years of experience in circumferential fracture analyses and experimentation, there has not been sufficient integration of work performed for other industries into analogous problems facing the oil and gas pipeline markets. Some very basic concepts and problems solved previously in these fields could have circumvented inconsistencies seen in the stress-based and strain-based analysis efforts. For example, in nuclear utility piping work, more detailed elastic-plastic fracture analyses were always validated in their ability to predict loads and displacements (stresses and strains). The eventual implementation of these methodologies will result in acceleration of the industry adoption of higher-strength line-pipe steels.

Wilkowski, Gery M.; Rudland, David L.; Shim, Do-Jun; Brust, Frederick W.; Babu, Sundarsanam

2008-06-30T23:59:59.000Z

77

Method for enhanced control of welding processes  

DOE Patents [OSTI]

Method and system for producing high quality welds in welding processes, in general, and gas tungsten arc (GTA) welding, in particular by controlling weld penetration. Light emitted from a weld pool is collected from the backside of a workpiece by optical means during welding and transmitted to a digital video camera for further processing, after the emitted light is first passed through a short wavelength pass filter to remove infrared radiation. By filtering out the infrared component of the light emitted from the backside weld pool image, the present invention provides for the accurate determination of the weld pool boundary. Data from the digital camera is fed to an imaging board which focuses on a 100.times.100 pixel portion of the image. The board performs a thresholding operation and provides this information to a digital signal processor to compute the backside weld pool dimensions and area. This information is used by a control system, in a dynamic feedback mode, to automatically adjust appropriate parameters of a welding system, such as the welding current, to control weld penetration and thus, create a uniform weld bead and high quality weld.

Sheaffer, Donald A. (Livermore, CA); Renzi, Ronald F. (Tracy, CA); Tung, David M. (Livermore, CA); Schroder, Kevin (Pleasanton, CA)

2000-01-01T23:59:59.000Z

78

Tensile Fracture of Welded Polymer Interfaces: Miscibility, Entanglements and Crazing  

E-Print Network [OSTI]

Large-scale molecular simulations are performed to investigate tensile failure of polymer interfaces as a function of welding time $t$. Changes in the tensile stress, mode of failure and interfacial fracture energy $G_I$ are correlated to changes in the interfacial entanglements as determined from Primitive Path Analysis. Bulk polymers fail through craze formation, followed by craze breakdown through chain scission. At small $t$ welded interfaces are not strong enough to support craze formation and fail at small strains through chain pullout at the interface. Once chains have formed an average of about one entanglement across the interface, a stable craze is formed throughout the sample. The failure stress of the craze rises with welding time and the mode of craze breakdown changes from chain pullout to chain scission as the interface approaches bulk strength. The interfacial fracture energy $G_I$ is calculated by coupling the simulation results to a continuum fracture mechanics model. As in experiment, $G_I$ increases as $t^{1/2}$ before saturating at the average bulk fracture energy $G_b$. As in previous simulations of shear strength, saturation coincides with the recovery of the bulk entanglement density. Before saturation, $G_I$ is proportional to the areal density of interfacial entanglements. Immiscibiltiy limits interdiffusion and thus suppresses entanglements at the interface. Even small degrees of immisciblity reduce interfacial entanglements enough that failure occurs by chain pullout and $G_I \\ll G_b$.

Ting Ge; Gary S. Grest; Mark O. Robbins

2014-10-07T23:59:59.000Z

79

E-Print Network 3.0 - alloy welded joints Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

arc welding is a unique arc welding process for deep Summary: welding (GTAW) in terms of penetration depth, joint preparation and thermal distortion (Ref. 2). Although... welding...

80

Automatic monitoring of vibration welding equipment  

DOE Patents [OSTI]

A vibration welding system includes vibration welding equipment having a welding horn and anvil, a host device, a check station, and a robot. The robot moves the horn and anvil via an arm to the check station. Sensors, e.g., temperature sensors, are positioned with respect to the welding equipment. Additional sensors are positioned with respect to the check station, including a pressure-sensitive array. The host device, which monitors a condition of the welding equipment, measures signals via the sensors positioned with respect to the welding equipment when the horn is actively forming a weld. The robot moves the horn and anvil to the check station, activates the check station sensors at the check station, and determines a condition of the welding equipment by processing the received signals. Acoustic, force, temperature, displacement, amplitude, and/or attitude/gyroscopic sensors may be used.

Spicer, John Patrick; Chakraborty, Debejyo; Wincek, Michael Anthony; Wang, Hui; Abell, Jeffrey A; Bracey, Jennifer; Cai, Wayne W

2014-10-14T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Dissimilar-welded failure analysis and development: Volume 6, Weld condition and remaining life assessment manual: Final report  

SciTech Connect (OSTI)

Step-by-step guidelines contained in a new engineering manual explain how to evaluate dissimilar metal weld loadings, assess the current state of damage, and predict remaining weld life. Suggested plant and operational modifications will help utility personnel identify root causes and avoid additional failures in a given boiler. Failure of dissimilar metal welds (DMWs) between the austenitic and ferritic steel tubing used in superheaters and reheaters constitutes a major cause of forced outages in fossil boilers. EPRI has undertaken a study of DMWs, reported in volumes 1-6 of this nine-volume series, to provide utilities with a systematic approach for identifying root causes, remedying identified problems, and estimating remaining DMW useful life. This manual follows the three-phase approach outlined in the EPRI guidelines for life extension (report CS-4778). The investigators subjected the samples to detailed metallurgical examination and established correlations among operating conditions, system stresses, and the extent of observed DMW cracking. These correlations were quantified in the PODIS computer code (prediction of damage in service code; EPRI report CS-4252, volume 7). The investigators documented this information in a manual explaining how to carry out life assessment of DMWs. These guidelines describe an analytic procedure that computes the current level of DMW damage based on operating temperature, the number and nature of cycles, and system stresses. They explain a procedure for supplementary destructive examinations to verify the analytic predictions. 10 refs., 20 figs., 2 tabs.

Not Available

1988-08-01T23:59:59.000Z

82

WELDING RESEARCH OCTOBER 2005-s156  

E-Print Network [OSTI]

of the welding fume reveals that gas metal arc welding (GMAW) fume consists pre- dominately of particle of the chemicals present in the in- haled particles. Particles or agglomerates between 0.1 and 1 µm can be exhaled with different size range capabilities to measure the particle size of gas metal arc welding (GMAW) fume

Eagar, Thomas W.

83

Contamination and solid state welds.  

SciTech Connect (OSTI)

Since sensitivity to contamination is one of the verities of solid state joining, there is a need for assessing contamination of the part(s) to be joined, preferably nondestructively while it can be remedied. As the surfaces that are joined in pinch welds are inaccessible and thus provide a greater challenge, most of the discussion is of the search for the origin and effect of contamination on pinch welding and ways to detect and mitigate it. An example of contamination and the investigation and remediation of such a system is presented. Suggestions are made for techniques for nondestructive evaluation of contamination of surfaces for other solid state welds as well as for pinch welds. Surfaces that have good visual access are amenable to inspection by diffuse reflection infrared Fourier transform (DRIFT) spectroscopy. Although other techniques are useful for specific classes of contaminants (such as hydrocarbons), DRIFT can be used most classes of contaminants. Surfaces such as the interior of open tubes or stems that are to be pinch welded can be inspected using infrared reflection spectroscopy. It must be demonstrated whether or not this tool can detect graphite based contamination, which has been seen in stems. For tubes with one closed end, the technique that should be investigated is emission infrared spectroscopy.

Mills, Bernice E.

2007-05-01T23:59:59.000Z

84

Fracture toughness of thick section dissimilar electron beam weld joints  

SciTech Connect (OSTI)

Microstructural investigations as well as crack tip opening displacement (CTOD) fracture toughness test based on elastic-plastic fracture mechanics were performed on single pass, full penetration similar and dissimilar electron beam (EB) welds of 40 mm thick 316L type austenitic steel and high alloyed fine tempered martensitic 9Cr 1Mo Nb V (P91 -ASTM A213) steel. The latter modified steel has been developed to fill up the gap between 12Cr steel and austenitic stainless steels with respect to the high temperature properties and better weldability. Furthermore, it shows a small thermal expansion coefficient and is not susceptible to stress corrosion cracking like the austenitic steel. The weldment properties were evaluated by microstructural analysis, microhardness, Charpy V- notch impact, and by newly developed flat microtensile specimens (0.5 mm thick). The dissimilar EB weld metal and HAZ of P91 steel has been shown to be microstructurally and mechanically distinct from both austenitic and martenistic parent metals. The use of microsized rectangular tensile specimens provides unique solution to the problem of the mechanical property determination of the narrow EB weld joint. The HAZ of the 9Cr1Mo steel exhibits extremely poor CTOD toughness properties in as-welded condition at room temperature. The CTOD values obtained were believed to be represent the intrinsic property of this zone, since the distance of the crack tip to the austenitic steel part was too large to receive a stress relaxation effect from low strength side on the crack tip (by accommodating the applied strains in the high toughness, lower strength 316L plate).

Kocak, M.; Junghans, E.

1994-12-31T23:59:59.000Z

85

Intraluminal tissue welding for anastomosis  

DOE Patents [OSTI]

A method and device are provided for performing intraluminal tissue welding for anastomosis of a hollow organ. A retractable catheter assembly is delivered through the hollow organ and consists of a catheter connected to an optical fiber, an inflatable balloon, and a biocompatible patch mounted on the balloon. The disconnected ends of the hollow organ are brought together on the catheter assembly, and upon inflation of the balloon, the free ends are held together on the balloon to form a continuous channel while the patch is deployed against the inner wall of the hollow organ. The ends are joined or "welded" using laser radiation transmitted through the optical fiber to the patch. A thin layer of a light-absorbing dye on the patch can provide a target for welding. The patch may also contain a bonding agent to strengthen the bond. The laser radiation delivered has a pulse profile to minimize tissue damage.

Glinsky, Michael (Livermore, CA); London, Richard (Orinda, CA); Zimmerman, George (Lafayette, CA); Jacques, Steven (Portland, OR)

1998-10-27T23:59:59.000Z

86

Intraluminal tissue welding for anastomosis  

DOE Patents [OSTI]

A method and device are provided for performing intraluminal tissue welding for anastomosis of a hollow organ. A retractable catheter assembly is delivered through the hollow organ and consists of a catheter connected to an optical fiber, an inflatable balloon, and a biocompatible patch mounted on the balloon. The disconnected ends of the hollow organ are brought together on the catheter assembly, and upon inflation of the balloon, the free ends are held together on the balloon to form a continuous channel while the patch is deployed against the inner wall of the hollow organ. The ends are joined or ``welded`` using laser radiation transmitted through the optical fiber to the patch. A thin layer of a light-absorbing dye on the patch can provide a target for welding. The patch may also contain a bonding agent to strengthen the bond. The laser radiation delivered has a pulse profile to minimize tissue damage. 8 figs.

Glinsky, M.; London, R.; Zimmerman, G.; Jacques, S.

1998-10-27T23:59:59.000Z

87

Laser Welding and Post Weld Treatment of Modified 9Cr-1MoVNb Steel [Laser  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Laser Welding of Metals > Laser Welding of Metals > Laser Welding and Post Weld Treatment of Modified 9Cr-1MoVNb Steel Capabilities Engineering Experimentation Reactor Safety Experimentation Aerosol Experiments System Components Laser Applications Overview Laser Oil & Gas Well Drilling Laser Heat Treatment Laser Welding of Metals On-line Monitoring Laser Beam Delivery Laser Glazing of Railroad Rails High Power Laser Beam Delivery Decontamination and Decommissioning Refractory Alloy Welding Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Laser Applications Laboratory Laser Welding of Metals Laser Welding and Post Weld Treatment of Modified 9Cr-1MoVNb Steel Zhiyue Xu Nuclear Engineering Division of Argonne National Laboratory

88

Refractory Alloy Welding [Laser Applications Laboratory] - Nuclear  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Refractory Alloy Welding Refractory Alloy Welding Capabilities Engineering Experimentation Reactor Safety Experimentation Aerosol Experiments System Components Laser Applications Overview Laser Oil & Gas Well Drilling Laser Heat Treatment Laser Welding of Metals On-line Monitoring Laser Beam Delivery Laser Glazing of Railroad Rails High Power Laser Beam Delivery Decontamination and Decommissioning Refractory Alloy Welding Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Laser Applications Laboratory Refractory Alloy Welding Project description: Welding of refractory metals such as vanadium alloys. Category: internal R&D project Bookmark and Share Butt weld of two 4 mm thick V-4Cr-4Ti plates made by a pulsed Nd:YAG laser

89

Identification of the selective corrosion existing at the seam weld of electric resistance-welded pipes  

Science Journals Connector (OSTI)

Abstract The selective corrosion existing at the seam weld of high frequency electric resistance welded pipes of carbon steel with low sulfur content in electrolyte solutions is revealed by localized electrochemical measurements. The seam weld, mainly consisted of ferrite, has more negative open circuit potential and higher anodic dissolution current density than the base metal consisting ferrite and pearlite. Between the seam weld and the base metal, there is a galvanic coupling effect accelerating the dissolution kinetics of the seam weld such that V-shaped corrosion groove preferentially occurs at the seam weld.

S.J. Luo; R. Wang

2014-01-01T23:59:59.000Z

90

Inspection of Nickel Alloy Welds: Results from Five Year International Program  

SciTech Connect (OSTI)

The U.S. Nuclear Regulatory Commission established and coordinated the international Program for the Inspection of Nickel alloy Components (PINC). The goal of PINC was to evaluate the capabilities of various nondestructive examination (NDE) techniques to detect and characterize primary water stress corrosion cracking (PWSCC) in dissimilar metal welds. Round-robin results showed that a combination of conventional and phased-array ultrasound provide the highest performance for flaw detection and depth sizing in dissimilar metal piping welds. The effective detection of flaws in bottom-mounted instrumentation penetrations by eddy current and ultrasound shows that it may be possible to reliably inspect these components in the field.

Prokofiev, Iouri; Cumblidge, Stephen E.; Doctor, Steven R.

2011-06-23T23:59:59.000Z

91

In-service repair of main pipelines by welding  

Science Journals Connector (OSTI)

A new approach to the repair of main pipelines by welding without removing them from service ... failure risk; safety of welding works on pipeline under pressure; use of different variants of repair by welding; s...

V. I. Makhnenko; V. S. But; O. I. Oleinik

2009-09-01T23:59:59.000Z

92

Method and device for frictional welding  

DOE Patents [OSTI]

A method for friction welding that produces a seal having essentially no gas porosity, comprises two rotationally symmetric, generally cylindrical members, spaced apart and coaxially aligned, that are rotated with respect to each other and brought together under high pressure. One member is preferably a generally cylindrical cannister that stores uranium within its hollow walls. The other member is preferably a generally cylindrical, hollow weld ring. An annular channel formed in the weld ring functions as an internal flash trap and is uniquely designed so that substantially all of the welding flash generated from the friction welding is directed into the channel`s recessed bottom. Also, the channel design limits distortion of the two members during the friction welding, process, further contributing to the complete seal that is obtained.

Peacock, H.B.

1991-01-01T23:59:59.000Z

93

Method and device for frictional welding  

DOE Patents [OSTI]

A method for friction welding that produces a seal having essentially no gas porosity, comprises two rotationally symmetric, generally cylindrical members, spaced apart and coaxially aligned, that are rotated with respect to each other and brought together under high pressure. One member is preferably a generally cylindrical cannister that stores uranium within its hollow walls. The other member is preferably a generally cylindrical, hollow weld ring. An annular channel formed in the weld ring functions as an internal flash trap and is uniquely designed so that substantially all of the welding flash generated from the friction welding is directed into the channel's recessed bottom. Also, the channel design limits distortion of the two members during the friction welding process, further contributing to the complete seal that is obtained.

Peacock, Harold B. (867 N. Belair Rd., Evans, GA 30809)

1992-01-01T23:59:59.000Z

94

Visible Light Emissions during Gas Tungsten Arc Welding and Its Application to Weld  

E-Print Network [OSTI]

\\ Visible Light Emissions during Gas Tungsten· Arc Welding and Its Application to Weld Image. EAGAR ABSTRACT. An experimental study was carried out to map the light emissions from a gas tungsten arc. The emissions were found to be dramat- ically different with different shielding gases, welding current and base

Eagar, Thomas W.

95

Neutron Diffraction Residual Strain Tensor Measurements Within The Phase IA Weld Mock-up Plate P-5  

SciTech Connect (OSTI)

Oak Ridge National Laboratory (ORNL) has worked with NRC and EPRI to apply neutron and X-ray diffraction methods to characterize the residual stresses in a number of dissimilar metal weld mockups and samples. The design of the Phase IA specimens aimed to enable stress measurements by several methods and computational modeling of the weld residual stresses. The partial groove in the 304L stainless steel plate was filled with weld beads of Alloy 82. A summary of the weld conditions for each plate is provided in Table 1. The plates were constrained along the long edges during and after welding by bolts with spring-loaded washers attached to the 1-inch thick Al backing plate. The purpose was to avoid stress relief due to bending of the welded stainless steel plate. The neutron diffraction method was one of the methods selected by EPRI for non-destructive through thickness strain and stress measurement. Four different plates (P-3 to P-6) were studied by neutron diffraction strain mapping, representing four different welding conditions. Through thickness neutron diffraction strain mappings at NRSF2 for the four plates and associated strain-free d-zero specimens involved measurement along seven lines across the weld and at six to seven depths. The mountings of each plate for neutron diffraction measurements were such that the diffraction vector was parallel to each of the three primary orthogonal directions of the plate: two in-plane directions, longitudinal and transverse, and the direction normal to the plate (shown in left figure within Table 1). From the three orthogonal strains for each location, the residual stresses along the three plate directions were calculated. The principal axes of the strain and stress tensors, however, need not necessarily align with the plate coordinate system. To explore this, plate P-5 was selected for examination of the possibility that the principal axes of strain are not along the sample coordinate system axes. If adequate data could be collected the goal would be to determine the strain tensor's orientation and magnitude of strain along each principle axis direction.

Hubbard, Camden R [ORNL

2011-09-01T23:59:59.000Z

96

Feasibility of underwater welding of highly irradiated in-vessel components of boiling-water reactors: A literature review  

SciTech Connect (OSTI)

In February 1997, the U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research (RES), initiated a literature review to assess the state of underwater welding technology. In particular, the objective of this literature review was to evaluate the viability of underwater welding in-vessel components of boiling water reactor (BWR) in-vessel components, especially those components fabricated from stainless steels that are subjected to high neutron fluences. This assessment was requested because of the recent increased level of activity in the commercial nuclear industry to address generic issues concerning the reactor vessel and internals, especially those issues related to repair options. This literature review revealed a preponderance of general information about underwater welding technology, as a result of the active research in this field sponsored by the U.S. Navy and offshore oil and gas industry concerns. However, the literature search yielded only a limited amount of information about underwater welding of components in low-fluence areas of BWR in-vessel environments, and no information at all concerning underwater welding experiences in high-fluence environments. Research reported by the staff of the U.S. Department of Energy (DOE) Savannah River Site and researchers from the DOE fusion reactor program proved more fruitful. This research documented relevant experience concerning welding of stainless steel materials in air environments exposed to high neutron fluences. It also addressed problems with welding highly irradiated materials, and primarily attributed those problems to helium-induced cracking in the material. (Helium is produced from the neutron irradiation of boron, an impurity, and nickel.) The researchers found that the amount of helium-induced cracking could be controlled, or even eliminated, by reducing the heat input into the weld and applying a compressive stress perpendicular to the weld path.

Lund, A.L.

1997-11-01T23:59:59.000Z

97

Nd:YAG laser welding aluminum alloys  

SciTech Connect (OSTI)

Autogenous Nd:YAG laser welding wrought 4047, 1100, 3003, 2219, 5052, 5086, 5456, and 6061 and cast A356 aluminum alloys to cast A356 aluminum alloy in restrained annular weld joints was investigated. The welds were 12.7 mm (0.375 in.) and 9.5 mm (0.375 in.) diameter with approximately 0.30 mm (0.012 in.) penetration. This investigation determined 4047 aluminum alloy to be the optimum alloy for autogenous Nd:YAG laser welding to cast A356 aluminum alloy. This report describes the investigation and its results.

Jimenez, E. Jr.

1992-02-01T23:59:59.000Z

98

Sensing the gas metal arc welding process  

SciTech Connect (OSTI)

Control of gas metal arc welding (GMAW) requires real-time sensing of the process. Three sensing techniques for GMAW are being developed at the Idaho National Engineering Laboratory (INEL). These are (1) noncontacting ultrasonic sensing using a laser/EMAT (electromagnetic acoustic transducer) to detect defects in the solidified weld on a pass-bypass basis, (2) integrated optical sensing using a CCD camera and a laser stripe to obtain cooling rate and weld bead geometry information, and (3) monitoring fluctuations in digitized welding voltage data to detect the mode of metal droplet transfer and assure that the desired mass input is achieved.

Carlson, N.M.; Johnson, J.A.; Smartt, H.B.; Watkins, A.D.; Larsen, E.D.; Taylor, P.L. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Waddoups, M.A. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

1992-10-01T23:59:59.000Z

99

Sensing the gas metal arc welding process  

SciTech Connect (OSTI)

Control of gas metal arc welding (GMAW) requires real-time sensing of the process. Three sensing techniques for GMAW are being developed at the Idaho National Engineering Laboratory (INEL). These are (1) noncontacting ultrasonic sensing using a laser/EMAT (electromagnetic acoustic transducer) to detect defects in the solidified weld on a pass-bypass basis, (2) integrated optical sensing using a CCD camera and a laser stripe to obtain cooling rate and weld bead geometry information, and (3) monitoring fluctuations in digitized welding voltage data to detect the mode of metal droplet transfer and assure that the desired mass input is achieved.

Carlson, N.M.; Johnson, J.A.; Smartt, H.B.; Watkins, A.D.; Larsen, E.D.; Taylor, P.L. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Waddoups, M.A. (Idaho National Engineering Lab., Idaho Falls, ID (United States))

1992-01-01T23:59:59.000Z

100

Welding shield for coupling heaters  

DOE Patents [OSTI]

Systems for coupling end portions of two elongated heater portions and methods of using such systems to treat a subsurface formation are described herein. A system may include a holding system configured to hold end portions of the two elongated heater portions so that the end portions are abutted together or located near each other; a shield for enclosing the end portions, and one or more inert gas inlets configured to provide at least one inert gas to flush the system with inert gas during welding of the end portions. The shield may be configured to inhibit oxidation during welding that joins the end portions together. The shield may include a hinged door that, when closed, is configured to at least partially isolate the interior of the shield from the atmosphere. The hinged door, when open, is configured to allow access to the interior of the shield.

Menotti, James Louis (Dickinson, TX)

2010-03-09T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Multi-mode ultrasonic welding control and optimization  

DOE Patents [OSTI]

A system and method for providing multi-mode control of an ultrasonic welding system. In one embodiment, the control modes include the energy of the weld, the time of the welding process and the compression displacement of the parts being welded during the welding process. The method includes providing thresholds for each of the modes, and terminating the welding process after the threshold for each mode has been reached, the threshold for more than one mode has been reached or the threshold for one of the modes has been reached. The welding control can be either open-loop or closed-loop, where the open-loop process provides the mode thresholds and once one or more of those thresholds is reached the welding process is terminated. The closed-loop control provides feedback of the weld energy and/or the compression displacement so that the weld power and/or weld pressure can be increased or decreased accordingly.

Tang, Jason C.H.; Cai, Wayne W

2013-05-28T23:59:59.000Z

102

management  

National Nuclear Security Administration (NNSA)

5%2A en Management and Budget http:nnsa.energy.govaboutusouroperationsmanagementandbudget

P...

103

Seal welded cast iron nuclear waste container  

DOE Patents [OSTI]

This invention identifies methods and articles designed to circumvent metallurgical problems associated with hermetically closing an all cast iron nuclear waste package by welding. It involves welding nickel-carbon alloy inserts which are bonded to the mating plug and main body components of the package. The welding inserts might be bonded in place during casting of the package components. When the waste package closure weld is made, the most severe thermal effects of the process are restricted to the nickel-carbon insert material which is far better able to accommodate them than is cast iron. Use of nickel-carbon weld inserts should eliminate any need for pre-weld and post-weld heat treatments which are a problem to apply to nuclear waste packages. Although the waste package closure weld approach described results in a dissimilar metal combination, the relative surface area of nickel-to-iron, their electrochemical relationship, and the presence of graphite in both materials will act to prevent any galvanic corrosion problem.

Filippi, Arthur M. (Pittsburgh, PA); Sprecace, Richard P. (Murrysville, PA)

1987-01-01T23:59:59.000Z

104

The robustness of dynamic vehicle performance to spot weld failures  

Science Journals Connector (OSTI)

Spot welds are the dominant joining method in the vehicle assembly process. As the automated assembly process is not perfect, some spot welds may be absent when the vehicle leaves the assembly line. Furthermore, spot welds are highly susceptible to fatigue, ... Keywords: Failure, Fatigue, Finite element analysis, Robustness, Spot welds, Structural dynamics

S. Donders; M. Brughmans; L. Hermans; C. Liefooghe; H. Van der Auweraer; W. Desmet

2006-05-01T23:59:59.000Z

105

Dilution and microsegregation in dissimilar metal welds between super austenitic  

E-Print Network [OSTI]

Dilution and microsegregation in dissimilar metal welds between super austenitic stainless steel the weld will also signi® cantly affect the corrosion resistance. Dissimilar metal welds between a super dissimilar weld. The dilution level was found to decrease as the ratio of volumetric ® ller metal feedrate

DuPont, John N.

106

Stress intensity factors for small fatigue cracks in tubular joints  

SciTech Connect (OSTI)

Some simple fracture mechanics models are presented for estimating stress intensity factors for small surface fatigue cracks in welded tubular joints. Model predictions are compared with large-scale experimental results for the cases of in-plane and out-of-plane bending in multi-brace tubular nodes. It is demonstrated that reasonably accurate predictions of the stress intensity factor are possible using a modified flat plate solution if the effects of weld geometry, load shedding and crack shape are adequately accounted for.

Monahan, C.C. [Memorial Univ. of Newfoundland, St. Johns, Newfoundland (Canada). Centre for Cold Ocean Resources Engineering; Dover, W.D. [University College, London (United Kingdom)

1995-12-31T23:59:59.000Z

107

Welding Hot Cracking of Side Shell of Drilling-Well Oil Storage Ship  

Science Journals Connector (OSTI)

...Cracks were found in the weld metal (WM) of weld-section of side shell of drilling-well oil storage ship when performing post weld radiographic...

Zhi-wei Yu; Xiao-lei Xu

2014-11-01T23:59:59.000Z

108

Influence of welding passes on grain orientation -the example of a multi-pass V-weld.  

E-Print Network [OSTI]

Evaluation (CANDE), derived from a dissimilar metal weld (DMW) with buttering. Comparisons are made using

Paris-Sud XI, Université de

109

Technical Letter Report - Analysis of Ultrasonic Data on Piping Cracks at Ignalina Nuclear Power Plant Before and After Applying a Mechanical Stress Improvement Process, JCN-N6319, Task 2  

SciTech Connect (OSTI)

Pacific Northwest National Laboratory (PNNL) is assisting the United States Nuclear Regulatory Commission (NRC) in developing a position on the management of primary water stress corrosion cracking (PWSCC) in piping systems previously analyzed for leak-before-break (LBB). Part of this work involves determining whether inspections alone are sufficient or if inspections plus mitigation techniques are needed. The work described in this report addresses the reliability of ultrasonic phased-array (PA) examinations for inspection of cracks that have been subjected to the mitigation method of mechanical stress improvement process (MSIP). It is believed that stresses imparted during MSIP may make ultrasonic crack responses in piping welds more difficult to detect and accurately characterize. To explore this issue, data were acquired, both before and after applying MSIP, and analyzed from cracked areas in piping at the Ignalina Nuclear Power Plant (INPP) in Lithuania. This work was performed under NRC Project JCN-N6319, PWSCC in Leak-Before-Break Systems.

Anderson, Michael T.; Cumblidge, Stephen E.; Crawford, Susan L.

2008-02-26T23:59:59.000Z

110

Characteristics of the weld interface in dissimilar austenitic-pearlitic steel welds  

SciTech Connect (OSTI)

The weld interface in dissimilar alloy welds between austenitic and pearlitic steels was observed directly by using scanning and transmission electron microscopy, and energy-dispersive x-ray spectrometry. Two types of weld interface were found in the joints. One was the austenite/martensite-like interface that formed the boundary between the mixed weld metal zone and the partially mixed transitional zone. The other is the martensite-like/ferrite interface that is the true liquid-solid boundary of the joint. These interfaces can exist independently in different joints and can also coexist in one joint, depending on the Cr and Ni contents of the filler metals and alloy in the base metals. The formation mechanism of the weld interface and its effect on the mechanical properties of the welded joint are discussed.

Pan, C.; Zhang, Z. (Wuhan Transportation Univ. (China). Dept. of Marine Mechanical Engineering)

1994-09-01T23:59:59.000Z

111

Automated generation of weld path trajectories.  

SciTech Connect (OSTI)

AUTOmated GENeration of Control Programs for Robotic Welding of Ship Structure (AUTOGEN) is software that automates the planning and compiling of control programs for robotic welding of ship structure. The software works by evaluating computer representations of the ship design and the manufacturing plan. Based on this evaluation, AUTOGEN internally identifies and appropriately characterizes each weld. Then it constructs the robot motions necessary to accomplish the welds and determines for each the correct assignment of process control values. AUTOGEN generates these robot control programs completely without manual intervention or edits except to correct wrong or missing input data. Most ship structure assemblies are unique or at best manufactured only a few times. Accordingly, the high cost inherent in all previous methods of preparing complex control programs has made robot welding of ship structures economically unattractive to the U.S. shipbuilding industry. AUTOGEN eliminates the cost of creating robot control programs. With programming costs eliminated, capitalization of robots to weld ship structures becomes economically viable. Robot welding of ship structures will result in reduced ship costs, uniform product quality, and enhanced worker safety. Sandia National Laboratories and Northrop Grumman Ship Systems worked with the National Shipbuilding Research Program to develop a means of automated path and process generation for robotic welding. This effort resulted in the AUTOGEN program, which has successfully demonstrated automated path generation and robot control. Although the current implementation of AUTOGEN is optimized for welding applications, the path and process planning capability has applicability to a number of industrial applications, including painting, riveting, and adhesive delivery.

Sizemore, John M. (Northrop Grumman Ship Systems); Hinman-Sweeney, Elaine Marie; Ames, Arlo Leroy

2003-06-01T23:59:59.000Z

112

Welding of uranium and uranium alloys  

SciTech Connect (OSTI)

The major reported work on joining uranium comes from the USA, Great Britain, France and the USSR. The driving force for producing this technology base stems from the uses of uranium as a nuclear fuel for energy production, compact structures requiring high density, projectiles, radiation shielding, and nuclear weapons. This review examines the state-of-the-art of this technology and presents current welding process and parameter information. The welding metallurgy of uranium and the influence of microstructure on mechanical properties is developed for a number of the more commonly used welding processes.

Mara, G.L.; Murphy, J.L.

1982-03-26T23:59:59.000Z

113

Development of steel plate and welding material with superior preferential corrosion resistance in welded joint  

SciTech Connect (OSTI)

The effects of chemical composition and microstructure on preferential corrosion of YP 420MPa steel were investigated. The test results indicated that the Ni addition prevented preferential corrosion in weld metal and heat affected zone (HAZ). The high contents of C and Cy accelerated preferential corrosion in HAZ. Inhibition of the creation of M-A constituents was effective in preventing the localized corrosion in HAZ. The localized corrosion in the welded joint was prevented by increasing the rest potential of weld metal by adding of Cr or Ni to the weld metal.

Kimura, Mitsuo; Miyata, Yukio; Saito, Yoshiyuki; Nakano, Yoshifumi [Kawasaki Steel Corp., Chiba (Japan)

1994-12-31T23:59:59.000Z

114

Welding of HSLA-100 steel using ultra low carbon bainitic weld metal to eliminate preheating  

SciTech Connect (OSTI)

Advanced high strength steels such as the Navy`s HSLA-100 and HSLA-80 contain sufficiently low carbon levels to be weldable without preheating. Unfortunately, commercial filler metals specifically designed to weld these steels without costly preheating have not yet been developed. The objective of this paper is to show that the Navy`s advanced steels can be welded by gas metal-arc (GMAW) and gas tungsten-arc welding (GTAW) without preheating by using filler metal compositions that produce weld metal with an ultra-low carbon bainitic (ULCB) microstructure. Filler metals were fabricated from vacuum induction melted (VIM) ingots containing ultra-low levels of C, O and N. HSLA-100 plate and plate from the VIM ingots were welded by both GMAW and GTAW with Ar-5% CO{sub 2} shielding gas using welding conditions to achieve cooling times from 800 to 500 C (t{sub 8-5}) from 35 to 14 sec. Weld metal tensile, hardness and CVN impact toughness testing as well as microstructural studies using transmission electron microscopy were conducted. The ULCB weld metal was relatively insensitive to cooling rate, resulting in good strength and toughness values over a wide range of t{sub 8-5} cooling times. Filler metal compositions which met the mechanical property requirements for HSLA-100, HSLA-80 and HSLA-65 weld metal were developed.

Devletian, J.H.; Singh, D.; Wood, W.E. [Oregon Graduate Inst. of Science and Technology, Portland, OR (United States)

1996-12-31T23:59:59.000Z

115

Fatique Resistant, Energy Efficient Welding Program, Final Technical Report  

SciTech Connect (OSTI)

The program scope was to affect the heat input and the resultant weld bead geometry by synchronizing robotic weave cycles with desired pulsed waveform shapes to develop process parameters relationships and optimized pulsed gas metal arc welding processes for welding fatique-critical structures of steel, high strength steel, and aluminum. Quality would be addressed by developing intelligent methods of weld measurement that accurately predict weld bead geometry from process information. This program was severely underfunded, and eventually terminated. The scope was redirected to investigate tandem narrow groove welding of steel butt joints during the one year of partial funding. A torch was designed and configured to perform a design of experiments of steel butt weld joints that validated the feasability of the process. An initial cost model estimated a 60% cost savings over conventional groove welding by eliminating the joint preparation and reducing the weld volume needed.

Egland, Keith; Ludewig, Howard

2006-05-25T23:59:59.000Z

116

Pulsed Magnetic Welding for Advanced Core and Cladding Steel  

SciTech Connect (OSTI)

To investigate a solid-state joining method, pulsed magnetic welding (PMW), for welding the advanced core and cladding steels to be used in Generation IV systems, with a specific application for fuel pin end-plug welding. As another alternative solid state welding technique, pulsed magnetic welding (PMW) has not been extensively explored on the advanced steels. The resultant weld can be free from microstructure defects (pores, non-matallic inclusions, segregation of alloying elements). More specifically, the following objectives are to be achieved, 1) To design a suitable welding apparatus fixture, and optimize welding parameters for repeatable and acceptable joining of the fuel pin end-plug. The welding will be evaluated using tensile tests for lap joint weldments and helium leak tests for the fuel pin end-plug. 2) investigate the microstructural and mechanical properties changes in PMW weldments of proposed advanced core and cladding alloys. 3) Simulate the irradiation effects on the PWM weldments using ion irradiation.

Cao, Guoping; Yang, Yong

2013-12-19T23:59:59.000Z

117

Method and apparatus for real time weld monitoring  

DOE Patents [OSTI]

An improved method and apparatus are provided for real time weld monitoring. An infrared signature emitted by a hot weld surface during welding is detected and this signature is compared with an infrared signature emitted by the weld surface during steady state conditions. The result is correlated with weld penetration. The signal processing is simpler than for either UV or acoustic techniques. Changes in the weld process, such as changes in the transmitted laser beam power, quality or positioning of the laser beam, change the resulting weld surface features and temperature of the weld surface, thereby resulting in a change in the direction and amount of infrared emissions. This change in emissions is monitored by an IR sensitive detecting apparatus that is sensitive to the appropriate wavelength region for the hot weld surface.

Leong, Keng H. (Lemont, IL); Hunter, Boyd V. (Bolingbrook, IL)

1997-01-01T23:59:59.000Z

118

Analysis of a Defected Dissimilar Metal Weld in a PWR Power Plant  

SciTech Connect (OSTI)

During the refueling outage 2000, inspections of the RC-loops of one of the Ringhals PWR-units, Ringhals 4, indicated surface breaking defects in the axial direction of the piping in a dissimilar weld between the Low alloy steel nozzle and the stainless safe end in the hot leg. In addition some indications were found that there were embedded defects in the weld material. These defects were judged as being insignificant to the structural integrity. The welds were inspected in 1993 with the result that no significant indications were found. The weld it self is a double U weld, where the thickness of the material is ideally 79,5 mm. Its is constructed by Inconel 182 weld material. At the nozzle a buttering was applied, also by Inconel 182. The In-service inspection, ISI, of the object indicated four axial defects, 9-16 mm deep. During fabrication, the areas where the defects are found were repaired at least three times, onto a maximum depth of 32 mm. To evaluate the defects, 6 boat samples from the four axial defects were cut from the perimeter and shipped to the hot-cell laboratory for further examination. This examination revealed that the two deep defects had been under sized by the ISI outside the requirement set by the inspection tolerances, while the two shallow defects were over sized, but within the tolerances of the detection system. When studying the safety case it became evident that there were several missing elements in the way this problems is handled with respect to the Swedish safety evaluation code. Among these the most notable at the beginning was the absence of reliable fracture mechanical data such as crack growth laws and fracture toughness at elevated temperature. Both these questions were handled by the project. The fracture mechanical evaluation has focused on a fit for service principal. Thus defects both in the unaffected zones and the disturbed zones, boat sample cutouts, of the weld have been analyzed. With reference to the Swedish safety evaluation system in accordance to the regulatory demands, a safety evaluation was performed using the R6-method. The failure assessment diagram is modified by the addition of the ASME XI safety factors both for limit load analysis and fracture assessment. This results in a very high conservatism since the secondary stresses such as residual stresses are high in the area. In order to quantify this effect an analysis in accordance to ASME IWB-3640, App. C was performed. This analysis provides the decision-makers with a sensitivity study; important to have to value the real risk of any missed defects in the area. (authors)

Efsing, P. [Barseback Kraft AB, P.O. Box 524, Loddekopinge SE-246 25 (Sweden); Lagerstrom, J. [Vattenfall AB, Ringhals, 430 22 Vaeroebacka (Sweden)

2002-07-01T23:59:59.000Z

119

Current Issues and Problems in Welding Science  

Science Journals Connector (OSTI)

...and properties. Rapid heating, cooling...thermomechanical simulation, and welding of...recent advances in rapid so-lidification...prevalent during rapid solidification...microstruc-tural modeling within the HAZ and...progressively replaced by automated systems to achieve...

S. A. David; T. DebRoy

1992-07-24T23:59:59.000Z

120

Vibration welding system with thin film sensor  

DOE Patents [OSTI]

A vibration welding system includes an anvil, a welding horn, a thin film sensor, and a process controller. The anvil and horn include working surfaces that contact a work piece during the welding process. The sensor measures a control value at the working surface. The measured control value is transmitted to the controller, which controls the system in part using the measured control value. The thin film sensor may include a plurality of thermopiles and thermocouples which collectively measure temperature and heat flux at the working surface. A method includes providing a welder device with a slot adjacent to a working surface of the welder device, inserting the thin film sensor into the slot, and using the sensor to measure a control value at the working surface. A process controller then controls the vibration welding system in part using the measured control value.

Cai, Wayne W; Abell, Jeffrey A; Li, Xiaochun; Choi, Hongseok; Zhao, Jingzhou

2014-03-18T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Wet welding qualification trials at 35 MSW  

SciTech Connect (OSTI)

Wet welding is gaining increased attention and attraction for application on marine buildings and offshore structures all over the world because of its versatility, flexibility and mobility in combination with low investment costs. In a common research and development project between PETROBRAS/CENPES, Rio de Janeiro, Brazil and GKSS Research Centre, Geesthacht, Germany wet welding qualification trials have been performed in different water depths up to 35 msw. The tests have been performed with newly developed electrodes in two different wet welding procedures. The experiments have been carried out on SS- as well as on 5F-specimens acc. ANSI/AWS D 3.6-89. Results will be presented in respect to the performance of the two welding procedures especially with regard to the avoidance of hydrogen induced cold cracking and high hardness values.

Dos Santos, V.R.; Teixeira, C.J. [Petrobras/CENPES, Rio de Janeiro (Brazil); Szelagowski, P.J.F. [GKSS Research Center, Geesthacht (Germany)

1993-12-31T23:59:59.000Z

122

The 'world's largest' Inconel waterwall weld overlay  

SciTech Connect (OSTI)

An 11,000 square foot Inconel 655 weld repaired severe wastage caused by low NOx firing with coal/petcoke at the Belledune generating station in New Brunswick, Canada. 1 ref., 1 fig., 3 photos.

MacLean, K.; Fournier, E.; Gomez-Grande, J.; Scandroli, T. [New Brunswick Power Generation (United States)

2009-11-15T23:59:59.000Z

123

Utilization of a finite element model to verify spent nuclear fuel storage rack welds  

SciTech Connect (OSTI)

Elastic and plastic finite element analyses were performed for the inner tie block assembly of a 25 port fuel rack designed for installation at the Idaho National Engineering and Environmental Laboratory (INEEL) Idaho Chemical Processing Plant (ICPP). The model was specifically developed to verify the adequacy of certain welds joining components of the fuel storage rack assembly. The work scope for this task was limited to an investigation of the stress levels in the inner tie welds when the rack was subjected to seismic loads. Structural acceptance criteria used for the elastic calculations performed were as defined by the rack`s designer. Structural acceptance criteria used for the plastic calculations performed as part of this effort were as defined in Subsection NF and Appendix F of Section III of the ASME Boiler and Pressure Vessel Code. The results confirm that the welds joining the inner tie block to the surrounding rack structure meet the acceptance criteria. The analysis results verified that the inner tie block welds should be capable of transferring the expected seismic load without structural failure.

Nitzel, M.E.

1998-07-01T23:59:59.000Z

124

Laser welding dissimilar reflective alloys  

SciTech Connect (OSTI)

This project, jointly sponsored by Rocketdyne and CSTAR, involves the development of laser joining of materials which have heretofore been impractical to bond. Of particular interest are joints between stainless steel and copper and also aluminum 6061 to aluminum 2219. CSTAR has a unique opportunity in this area since both the process and development and diagnostics are of interest to industry. Initial results using the pulse tailored laser welding technique developed in CLA for joining crack sensitive materials have proven promising for the aluminum joints based upon metallurgical and electronic microprobe analysis. A declaration of success requires additional mechanical testing. A CW technique has been applied to the stainless-copper joining with some preliminary success. These joints are of significant interest for aeronautics and rocket propulsion applications and the project is expected to continue.

Mccay, M.H.; Gopinathan, S.; Kahlen, F.; Speigel, L.

1993-01-01T23:59:59.000Z

125

Design consideration for wet welded joints  

SciTech Connect (OSTI)

Wet welding has become a joining technique that under certain circumstances can provide results which cannot be distinguished between wet or dry production and the achievable mechanical quality is comparable to dry atmospheric welds. Wet welding is not a process which can be applied easily and which can be properly handled by untrained diver welders. Wet welding is more than any other kind of welding process or procedure a joining technique that requires the full job-concentration and -knowledge of an excellent trained and skilled diver welder throughout the whole production time, who is 100% identifying himself with his task. Furthermore he must be fully aware of the production requirements and possible metallurgical/environmental reactions and outcomes. He must be able to be fully concentrated on the process performance throughout his total work shift. In short: he must be an outstanding expert in his field. The following paper will highlight these subjects and show the necessity of their exact observation to achieve excellent quality in wet welding.

Szelagowski, P.; Osthus, V. [GKSS Research Center, Geesthacht (Germany); Petershagen, H.; Pohl, R. [Univ. Hamburg (Germany). Inst. fuer Schiffbau; Lafaye, G. [Stolt Comex Seaway S.A., Marseille (France)

1996-12-01T23:59:59.000Z

126

Advanced tests of wet welded joints  

SciTech Connect (OSTI)

Wet Welding has in former times only been applied to secondary structural components. Nowadays wet welding has become an upcoming repair process due to high process flexibility, its low investment costs and its high versatility. Even the quality of the wet welded joints has been improved remarkably due to intensive and concentrated development activities. However, especially in the North Sea regions owners of offshore structures and classifying authorities still hesitate to recognize the process as a reliable alternative to dry hyperbaric welding repair methods. It therefore requires further activities especially in the field of data development for life prediction of such repaired components. Advanced testing methods are necessary, additional design criteria are to be developed and achievable weldment quality data are to be included in acknowledged and approved standards and recommendations to improve the credibility of the process and to solve the problem of quality assurance for wet welded joints. A comprehensive project, sponsored by the European Community under the Thermie Programme, is in progress to develop new testing procedures to generate the required data and design criteria for the future application of the wet welding process to main components of offshore structures. It is the aim of the project to establish additional fitness for purpose data for this process.

Pachniuk, I. [Stolt Comex Seaway S.A., Marseille (France); Petershagen, H.; Pohl, R. [Univ. Hamburg (Germany); Szelagowski, P.; Drews, O. [GKSS Research Centre, Geesthacht (Germany)

1994-12-31T23:59:59.000Z

127

Intelligent Control of Modular Robotic Welding Cell  

SciTech Connect (OSTI)

Although robotic machines are routinely used for welding, such machines do not normally incorporate intelligent capabilities. We are studying the general problem of formulating usable levels of intelligence into welding machines. From our perspective, an intelligent machine should: incorporate knowledge of the welding process, know if the process is operating correctly, know if the weld it is making is good or bad, have the ability to learn from its experience to perform welds, and be able to optimize its own performance. To this end, we are researching machine architecture, methods of knowledge representation, decision making and conflict resolution algorithms, methods of learning and optimization, human/machine interfaces, and various sensors. This paper presents work on the machine architecture and the human/machine interface specifically for a robotic, gas metal arc welding cell. Although the machine control problem is normally approached from the perspective of having a central body of control in the machine, we present a design using distributed agents. A prime goal of this work is to develop an architecture for an intelligent machine that will support a modular, plug and play standard. A secondary goal of this work is to formulate a human/machine interface that treats the human as an active agent in the modular structure.

Smartt, Herschel Bernard; Kenney, Kevin Louis; Tolle, Charles Robert

2002-04-01T23:59:59.000Z

128

Towards Real Time Diagnostics of Hybrid Welding Laser/GMAW  

SciTech Connect (OSTI)

Methods are currently being developed towards a more robust system real time feedback in the high throughput process combining laser welding with gas metal arc welding. A combination of ultrasonic, eddy current, electronic monitoring, and visual techniques are being applied to the welding process. Initial simulation and bench top evaluation of proposed real time techniques on weld samples are presented along with the concepts to apply the techniques concurrently to the weld process. Consideration for the eventual code acceptance of the methods and system are also being researched as a component of this project. The goal is to detect defects or precursors to defects and correct when possible during the weld process.

Timothy Mcjunkin; Dennis C. Kunerth; Corrie Nichol; Evgueni Todorov; Steve Levesque; Feng Yu; Robert Danna Couch

2013-07-01T23:59:59.000Z

129

Effects of xenon cover gas in CO/sub 2/ laser welding  

SciTech Connect (OSTI)

Weld spatter in CO/sub 2/ laser welding is detrimental to miniature components. The effects of using xenon gas as an inert laser welding atmosphere to reduce weld spatter are discussed. The laser plume characteristics, weld penetration, and weld spatter are evaluated.

Hendrix, T.L.

1980-07-01T23:59:59.000Z

130

Evaluation of Manual Ultrasonic Examinations Applied to Detect Flaws in Primary System Dissimilar Metal Welds at North Anna Power Station  

SciTech Connect (OSTI)

During a recent inservice inspection (ISI) of a dissimilar metal weld (DMW) in an inlet (hot leg) steam generator nozzle at North Anna Power Station Unit 1, several axially oriented flaws went undetected by the licensee's manual ultrasonic testing (UT) technique. The flaws were subsequently detected as a result of outside diameter (OD) surface machining in preparation for a full structural weld overlay. The machining operation uncovered the existence of two through-wall flaws, based on the observance of primary water leaking from the DMW. Further ultrasonic tests were then performed, and a total of five axially oriented flaws, classified as primary water stress corrosion cracking (PWSCC), were detected in varied locations around the weld circumference.

Anderson, Michael T.; Diaz, Aaron A.; Doctor, Steven R.

2012-06-01T23:59:59.000Z

131

Full scale experimental analysis of stress states in sleeve repairs of gas pipelines  

Science Journals Connector (OSTI)

This study discusses the experimental determination of stress states in sleeve repairs of underground gas pipelines. Work was done to define the effects of the reduction of pressure during welding, the load and place of positioning clamps, the length of the repair sleeve, and the use of O'ring-based devices to prevent gas leakage. Tests were carried out in reinforcements, welded with internal pressure equal to 60, 80 and 100% of the service pressure. High stresses were generated in tests carried out with short sleeves and O'rings, and occurred once the sleeve was fully welded and the pipeline pressure re-established. Maximum stresses, up to 270MPa, were generated after about 1min following closing of venting valves, on tests with artificial gas leaks. From the results of these experimental studies, it is concluded that several operative aspects could be optimised, to minimise the stresses in the reinforcements and to reduce the risk of failures.

M.D Chapetti; J.L Otegui; C Manfredi; C.F Martins

2001-01-01T23:59:59.000Z

132

Waterside Stress Assisted Corrosion (SAC) of Boiler Tubes  

E-Print Network [OSTI]

Waterside Stress Assisted Corrosion (SAC) of Boiler Tubes School of Materials Science Boiler Areas Susceptible to SAC · Generally SAC initiates near weld joints on cold side of tubes · SAC cracks are difficult to detect inaccessibility · Failures Detected at Various Locations in Boilers

Das, Suman

133

A Glove Box Enclosed Gas-Tungsten Arc Welding System  

SciTech Connect (OSTI)

This report describes an inert atmosphere enclosed gas-tungsten arc welding system which has been assembled in support of the MC2730, MC2730A and MC 3500 Radioisotope Thermoelectric Generator (RTG) Enhanced Surveillance Program. One goal of this program is to fabricate welds with microstructures and impurity levels which are similar to production heat source welds previously produced at Los Alamos National Laboratory and the Mound Facility. These welds will subsequently be used for high temperature creep testing as part of the overall component lifetime assessment. In order to maximize the utility of the welding system, means for local control of the arc atmosphere have been incorporated and a wide range of welding environments can easily be evaluated. The gas-tungsten arc welding system used in the assembly is computer controlled, includes two-axis and rotary motion, and can be operated in either continuous or pulsed modes. The system can therefore be used for detailed research studies of welding impurity effects, development of prototype weld schedules, or to mimic a significant range of production-like welding conditions. Fixturing for fabrication of high temperature creep test samples have been designed and constructed, and weld schedules for grip-tab and test welds have been developed. The microstructure of these welds have been evaluated and are consistent with those used during RTG production.

Reevr, E, M; Robino, C.V.

1999-07-01T23:59:59.000Z

134

Apparatus for maintaining aligment of a shrinking weld joint in an electron-beam welding operation  

DOE Patents [OSTI]

The invention is directed to an apparatus for automatically maintaining a shrinking weld joint in alignement with an electron beam during an electron-beam multipass-welding operation. The apparatus utilizes a bias means for continually urging a workpiece-supporting face plate away from a carriage mounted base that rotatably supports the face plate. The extent of displacement of the face plate away from the base in indicative of the shrinkage occuring in the weld joint area. This displacement is measured and is used to move the base on the carriage a distance equal to one-half the displacement for aligning the weld joint with the electron beam during each welding pass.

Trent, J.B.; Murphy, J.L.

1980-01-03T23:59:59.000Z

135

Surge Nozzle NDE Specimen Mechanical Stress Improvement Analysis  

SciTech Connect (OSTI)

The purpose of this project was to perform a finite element analysis of a pressurized water reactor pressurizer surge nozzle mock-up to predict both the weld residual stresses created in its construction and the final stress state after the application of the Mechanical Stress Improvement Process (MSIP). Strain gages were applied to the inner diameter of the mock-up to record strain changes during the MSIP. These strain readings were used in an attempt to calculate the final stress state of the mock-up as well.

Fredette, Lee F.

2011-07-14T23:59:59.000Z

136

Simple test for dissimilar-metal welds  

SciTech Connect (OSTI)

A simplified accelerated test procedure has been developed for testing dissimilar-metal welds between austenitic stainless steels and low-alloy ferritic steels. The failure of these welded joints in operating steam generators of fossil-fired power plants has become an increasing problem for the utility industry. The proposed test is a three-point loading, bent-beam test that uses sheet specimens taken from a dissimilar-metal weldment. Tests were conducted in a simple test fixture where the specimens are loaded with a set-screw. To determine whether the test produces the same type of failure as those produced in a power plant, tests were conducted on specimens taken from a weld between Type 316 stainless steel and 2 1/4 Cr-1 Mo steel plates using Type 309 stainless steel filler metal. The specimens were loaded in the test fixture at room temperature and then thermally cycled between room temperature and 593/sup 0/C (1099/sup 0/F) by placing the test apparatus in a box furnace (thermal cycling during power plant operation plays a major role in the weld failure during service). The specimens were kept in the furnace for 20 to 70 hours (h), cooled to room temperature, and then the cycle was repeated. Metallographic examination of specimens cycled as few as 64 times with a total of 2300 h at 593/sup 0/C revealed that the specimens contained cracks similar to the cracks observed on dissimilar-metal welds cut from steam tubes after long-time elevated-temperature service racks similar to the cracks observed on dissimilar-metal welds cut from steam tubes after longtime elevated-temperature service in a fossil-fired steam generator. All indications are that this simple accelerated test could be used as a screening procedure to compare the relative behavior of ''improved'' welds in future research and development programs.

Klueh, R.L.; King, J.F.; Griffith, J.L.

1983-06-01T23:59:59.000Z

137

Training Program EHS ~ 244: Resistance Spot Welding Safety Training  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

4: Resistance Spot Welding Safety Training 4: Resistance Spot Welding Safety Training Course Syllabus Subject Category: Resistance Spot Welding Course Prerequisite: None Course Length: 25 minutes Medical Approval: No Delivery Mode: Web-Based Course Goal: Participants will be introduced to resistance spot welding processes, hazards, and safe work practices. Course Objectives: By the end of this course, you will be able to: * Identify resistance spot welding processes * Identify hazards, safe work practices, and personal protective equipment associated with resistance spot welding * Recognize the purpose of resistance spot welding schedules * Locate resistance spot welding schedule Subject Matter Expert: Joe Dionne x 7586 Training Compliance: 29 CFR 1910 Subparts O & Z, 29 CFR 1926 Subparts J & Z

138

FINITE ELEMENT ANALYSIS OF STEEL WELDED COVERPLATE INCLUDING COMPOSITE DOUBLERS  

E-Print Network [OSTI]

With the increasing focus on welded bridge members resulting in crack initiation and propagation, there is a large demand for creative solutions. One of these solutions includes the application of composite doublers over the critical weld. In order...

Petri, Brad

2008-05-15T23:59:59.000Z

139

Ultrasonic Flaw Detection of Cracks and Machined Flaws as Observed Through Austenitic Stainless Steel Piping Welds  

SciTech Connect (OSTI)

Piping welds in the pressure boundary of light water reactors (LWRs) are subject to a volumetric examination based on Section XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. Due to access limitations and high background radiation levels, the technique used is primarily ultrasonic rather than radiographic. Many of the austenitic welds in safety-related piping systems provide limited access to both sides of the weld, so a far-side examination is necessary. Historically, far-side inspections have performed poorly because of the coarse and elongated grains that make up the microstructures of austenitic weldments. The large grains cause the ultrasound to be scattered, attenuated, and redirected. Additionally, grain boundaries or weld geometry may reflect coherent ultrasonic echoes, making flaw detection and discrimination a more challenging endeavor. Previous studies conducted at the Pacific Northwest National Laboratory (PNNL) on ultrasonic far-side examinations in austenitic piping welds involved the application of conventional transducers, use of low-frequency Synthetic Aperture Focusing Techniques (SAFT), and ultrasonic phased-array (PA) methods on specimens containing implanted thermal fatigue cracks and machined reflectors [1-2]. From these studies, PA inspection provided the best results, detecting nearly all of the flaws from the far side. These results were presented at the Fifth International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurised Components in 2006. This led to an invitation to examine field-removed specimens containing service-induced intergranular stress corrosion cracks (IGSCC) at the Electric Power Research Institutes (EPRI) Nondestructive Evaluation (NDE) Center, in Charlotte, North Carolina. Results from this activity are presented.

Anderson, Michael T.; Cinson, Anthony D.; Crawford, Susan L.; Cumblidge, Stephen E.; Diaz, Aaron A.

2009-07-01T23:59:59.000Z

140

Plutonium metal and oxide container weld development and qualification  

SciTech Connect (OSTI)

Welds were qualified for a container system to be used for long-term storage of plutonium metal and oxide. Inner and outer containers are formed of standard tubing with stamped end pieces gas-tungsten-arc (GTA) welded onto both ends. The weld qualification identified GTA parameters to produce a robust weld that meets the requirements of the Department of Energy standard DOE-STD-3013-94, ``Criteria for the Safe Storage of Plutonium Metals and Oxides.``

Fernandez, R.; Horrell, D.R.; Hoth, C.W.; Pierce, S.W.; Rink, N.A.; Rivera, Y.M.; Sandoval, V.D.

1996-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Advanced Testing Techniques to Measure the PWSCC Resistance of Alloy 690 and its Weld Metals  

SciTech Connect (OSTI)

Wrought Alloy 600 and its weld metals (Alloy 182 and Alloy 82) were originally used in pressurized water reactors (PWRs) due to the material's inherent resistance to general corrosion in a number of aggressive environments and because of a coefficient of thermal expansion that is very close to that of low alloy and carbon steel. Over the last thirty years, stress corrosion cracking in PWR primary water (PWSCC) has been observed in numerous Alloy 600 component items and associated welds, sometimes after relatively long incubation times. The occurrence of PWSCC has been responsible for significant downtime and replacement power costs. As part of an ongoing, comprehensive program involving utilities, reactor vendors and engineering/research organizations, this report will help to ensure that corrosion degradation of nickel-base alloys does not limit service life and that full benefit can be obtained from improved designs for both replacement components and new reactors.

P.Andreson

2004-10-01T23:59:59.000Z

142

Effect of Post-Weld Heat Treatment on Creep Rupture Properties of Grade 91 Steel Heavy Section Welds  

SciTech Connect (OSTI)

This project will conduct a systematic metallurgical study on the effect of post-weld heat treatment (PWHT) on the creep rupture properties of P91 heavy section welds. The objective is to develop a technical guide for selecting PWHT parameters, and to predict expected creep-rupture life based on the selection of heat treatment parameters. The project consists of four interdependent tasks: Experimentally and numerically characterize the temperature fields of typical post-weld heat treatment procedures for various weld and joint configurations to be used in Gen IV systems. Characterize the microstructure of various regions, including the weld fusion zone, coarse-grain heat-affected zone, and fine-grain heat affected zone, in the welds that underwent the various welding and PWHT thermal histories. Conduct creep and creep-rupture testing of coupons extracted from actual and physically simulated welds. Establish the relationship among PWHT parameters, thermal histories, microstructure, creep, and creep-rupture properties.

Leijun Li

2012-11-02T23:59:59.000Z

143

Apparatus for the concurrent inspection of partially completed welds  

DOE Patents [OSTI]

An apparatus for the concurrent inspection of partially completed welds is described in which is utilized in combination with a moveable welder for forming a partially completed weld, and an ultrasonic generator mounted on a moveable welder in which is reciprocally moveable along a path of travel which is laterally disposed relative to the partially completed weld.

Smartt, Herschel B. (Idaho Falls, ID); Johnson, John A. (Idaho Falls, ID); Larsen, Eric D. (Idaho Falls, ID); Bitsoi, Rodney J. (Ririe, ID); Perrenoud, Ben C. (Rigby, ID); Miller, Karen S. (Idaho Falls, ID); Pace, David P. (Idaho Falls, ID)

2002-01-01T23:59:59.000Z

144

Electrochemical Testing of Gas Tungsten ARC Welded and Reduced Pressure Electron Beam Welded Alloy 22  

SciTech Connect (OSTI)

Alloy 22 (N06022) is the material selected for the fabrication of the outer shell of the nuclear waste containers for the Yucca Mountain high-level nuclear waste repository site. A key technical issue in the waste package program has been the integrity of the container weld joints. The currently selected welding process for fabricating and sealing the containers is the traditional gas tungsten arc welding (GTAW) or TIC method. An appealing faster alternative technique is reduced pressure electron beam (RPEB) welding. It was of interest to compare the corrosion properties of specimens prepared using both types of welding techniques. Standard electrochemical tests were carried on GTAW and RPEB welds as well as on base metal (non-welded) to determine their relative corrosion behavior in simulated concentrated water (SCW) at 90 C (alkaline), 1 M HCI at 60 C (acidic) and 1 M NaCl at 90 C (neutral) solutions. Results show that for all practical purposes, the three tested materials had the same electrochemical behavior in the three tested electrolytes.

S. Daniel Day; Frank M.G. Wong; Steven R. Gordon; Lana L. Wong; Raul B. Rebak

2006-05-08T23:59:59.000Z

145

Method and apparatus for welding precipitation hardenable materials  

DOE Patents [OSTI]

A method for welding together members consisting of precipitation age hardened materials includes the steps of selecting a weld filler material that has substantially the same composition as the materials being joined, and an age hardening characteristic temperature age threshold below that of the aging kinetic temperature range of the materials being joined, whereby after welding the members together, the resulting weld and heat affected zone (HAZ) are heat treated at a temperature below that of the kinetic temperature range of the materials joined, for obtaining substantially the same mechanical characteristics for the weld and HAZ, as for the parent material of the members joined. 5 figures.

Murray, H. Jr.; Harris, I.D.; Ratka, J.O.; Spiegelberg, W.D.

1994-06-28T23:59:59.000Z

146

Method and apparatus for welding precipitation hardenable materials  

DOE Patents [OSTI]

A method for welding together members consisting of precipitation age hardened materials includes the steps of selecting a weld filler material that has substantially the same composition as the materials being joined, and an age hardening characteristic temperature age threshold below that of the aging kinetic temperature range of the materials being joined, whereby after welding the members together, the resulting weld and heat affected zone (HAZ) are heat treated at a temperature below that of the kinetic temperature range of the materials joined, for obtaining substantially the same mechanical characteristics for the weld and HAZ, as for the parent material of the members joined.

Murray, Jr., Holt (Hopewell, NJ); Harris, Ian D. (Dublin, OH); Ratka, John O. (Cleveland Heights, OH); Spiegelberg, William D. (Parma, OH)

1994-01-01T23:59:59.000Z

147

Effect of soft root weld layer on fracture toughness of under-matched weld joints on Q+T steel  

SciTech Connect (OSTI)

Welding of quenched and tempered (Q+T) high strength low alloyed steels can cause weld strength undermatching to satisfy the toughness requirements for the weld deposit. Cost of pre-heating of these steels can be saved if one can prove that use of soft electrodes for root passes do not endanger the overall quality of the joint. By welding of 40 mm thick Q+T structural steel (grade HT 80), over-matched condition had appeared in the root area of the X-groove weld despite of welding consumable which would give entire weld under-matched properties. This is the effect of weld metal alloying by elements from base material. So, the weld joint is not protected against cold cracking especially in the root region, therefore, a high preheating should be used to reduce the possibility of this phenomenon. In this work soft (lower strength) filler metal was used for first two and four root passes of X-joint. In this case root area was also alloyed by elements from base material and obtained mis-matching factor M was higher than it was expected. So, one homogeneous and two non homogeneous weld joints (with two and four soft passes) were considered. Mechanical properties of weld joints were measured by round tensile bars taken from different parts of the weld. The under-matching factor of weld joint with two and four soft root passes was around 0.80--0.90 in the soft root layer. It was expected that uneven strength distribution along the fatigue crack tip line would affect fracture initiation behavior of all three different weld joints. The metallographical post-test sectioning has revealed the initiation points mainly at the lowest weld metal strength.

Rak, I.; Gliha, V.; Praunseis, Z. [Univ. of Maribor (Slovenia). Faculty of Mechanical Engineering; Kocak, M. [GKSS Research Center, Geesthacht (Germany). Inst. of Material Research

1996-12-01T23:59:59.000Z

148

Fluor Hanford Nuclear Material Stabilization Project Welding Manual  

SciTech Connect (OSTI)

The purpose of this section of the welding manual is to: (1) Provide a general description of the major responsibilities of the organizations involved with welding. (2) Provide general guidance concerning the application of codes related to welding. This manual contains requirements for welding for all Fluor Hanford (FH) welding operators working on the W460 Project, in the Plutonium Finishing Plant (PFP) at the U. S. Department of Energy (DOE) Hanford facilities. These procedures and any additional requirements for these joining processes can be used by all FH welding operators that are qualified. The Welding Procedure Specifications (WPS) found in this document were established from Procedure Qualification Records (PQR) qualified by FH specifically for the W460 Project. PQRs are permanent records of the initial testing and qualification program and are used to backup, and support, the WPS. The identification numbers of the supporting PQR(s) are recorded on each WPS. All PQRs are permanently stored under the supervision of the Fluor Hanford Welding Engineer (FHWE). New PQRs and WPSs will continue to be developed as necessary. The qualification of welders, welding operators and welding procedures will be performed for FH under supervision and concurrent of the FHWE. All new welding procedures to be entered in this manual or welder personnel to be added to the welder qualification database, shall be approved by the FHWE.

BERKEY, J.R.

2000-10-20T23:59:59.000Z

149

Welding and Weldability of Thorium-Doped Iridium Alloys  

SciTech Connect (OSTI)

Ir-0.3%W alloys doped with thorium are currently used as post-impact containment material for radioactive fuel in thermoelectric generators that provide stable electrical power for a variety of outer planetary space exploration missions. Welding and weldability of a series of alloys was investigated using arc and laser welding processes. Some of these alloys are prone to severe hot-cracking during welding. Weldability of these alloys was characterized using Sigmajig weldability test. Hot-cracking is influenced to a great extent by the fusion zone microstructure and composition. Thorium content and welding atmosphere were found to be very critical. The weld cracking behavior in these alloys can be controlled by modifying the fusion zone microstructure. Fusion zone microstructure was found to be controlled by welding process, process parameters, and the weld pool shape.

David, S.A.; Ohriner, E.K.; King, J.F.

2000-03-12T23:59:59.000Z

150

Method for the concurrent ultrasonic inspection of partially completed welds  

DOE Patents [OSTI]

A method for the concurrent ultrasonic inspection of partially completed welds is disclosed and which includes providing a pair of transducers which are individually positioned on the opposite sides of a partially completed weld to be inspected; moving the transducers along the length of and laterally inwardly and outwardly relative to the partially completed weld; pulsing the respective transducers to produce an ultrasonic signal which passes through or is reflected from the partially completed weld; receiving from the respective transducers ultrasonic signals which pass through or are reflected from the partially completed welds; and analyzing the ultrasonic signal which has passed through or is reflected from the partially completed weld to determine the presence of any weld defects.

Johnson, John A. (Idaho Falls, ID); Larsen, Eric D. (Idaho Falls, ID); Miller, Karen S. (Idaho Falls, ID); Smartt, Herschel B. (Idaho Falls, ID); McJunkin, Timothy R. (Idaho Falls, ID)

2002-01-01T23:59:59.000Z

151

Causal Factors of Weld Porosity in Gas Tungsten Arc Welding of Powder Metallurgy Produced Titanium Alloys  

SciTech Connect (OSTI)

ORNL undertook an investigation using gas tungsten arc (GTA) welding on consolidated powder metallurgy (PM) titanium (Ti) plate, to identify the causal factors behind observed porosity in fusion welding. Tramp element compounds of sodium and magnesium, residual from the metallothermic reduction of titanium chloride used to produce the titanium, were remnant in the starting powder and were identified as gas forming species. PM-titanium made from revert scrap where sodium and magnesium were absent, showed fusion weld porosity, although to a lesser degree. We show that porosity was attributable to hydrogen from adsorbed water on the surface of the powders prior to consolidation. The removal / minimization of both adsorbed water on the surface of titanium powder and the residues from the reduction process prior to consolidation of titanium powders, are critical to achieve equivalent fusion welding success similar to that seen in wrought titanium produced via the Kroll process.

Muth, Thomas R [ORNL; Yamamoto, Yukinori [ORNL; Frederick, David Alan [ORNL; Contescu, Cristian I [ORNL; Chen, Wei [ORNL; Lim, Yong Chae [ORNL; Peter, William H [ORNL; Feng, Zhili [ORNL

2013-01-01T23:59:59.000Z

152

Gas metal arc welding of duplex stainless steel using flux cored wire  

SciTech Connect (OSTI)

The effect of chemical compositions and welding parameters on pitting corrosion resistance and notch toughness of duplex stainless steel weld metals by FCAW was investigated. And the effect of welding parameters on hot cracking susceptibility of the FCAW weld metals was also studied. Pitting corrosion resistance was improved with the increase of Cr, Mo and N content in the weld metal, and it was also proved that the corrosion resistance was greatly affected by welding heat input. Hot cracking susceptibility of the weld metal was increased with the increase of welding current and welding speed.

Maruyama, T.; Ogawa, T.; Nishiyama, S.; Ushijima, A.; Yamashita, K. [Kobe Steel, Ltd., Fujisawa (Japan)

1994-12-31T23:59:59.000Z

153

Evaluation of weld porosity in laser beam seam welds: optimizing continuous wave and square wave modulated processes.  

SciTech Connect (OSTI)

Nd:YAG laser joining is a high energy density (HED) process that can produce high-speed, low-heat input welds with a high depth-to-width aspect ratio. This is optimized by formation of a ''keyhole'' in the weld pool resulting from high vapor pressures associated with laser interaction with the metallic substrate. It is generally accepted that pores form in HED welds due to the instability and frequent collapse of the keyhole. In order to maintain an open keyhole, weld pool forces must be balanced such that vapor pressure and weld pool inertia forces are in equilibrium. Travel speed and laser beam power largely control the way these forces are balanced, as well as welding mode (Continuous Wave or Square Wave) and shielding gas type. A study into the phenomenon of weld pool porosity in 304L stainless steel was conducted to better understand and predict how welding parameters impact the weld pool dynamics that lead to pore formation. This work is intended to aid in development and verification of a finite element computer model of weld pool fluid flow dynamics being developed in parallel efforts and assist in weld development activities for the W76 and future RRW programs.

Ellison, Chad M. (Honeywell FM& T, Kansas City, MO); Perricone, Matthew; Faraone, Kevin M. (Honeywell FM& T, Kansas City, MO); Roach, Robert Allen; Norris, Jerome T.

2007-02-01T23:59:59.000Z

154

Optimization of Weld Bead Penetration in Pulsed Gas Metal Arc Welding using Genetic Algorithm  

E-Print Network [OSTI]

Abstract The weld quality is highly influenced by various process parameters involved in the process. This can be achieved by meeting quality requirements of bead geometry. Inadequate depth of penetration will contribute to failure of the welded structure. This paper presents the development of genetic algorithm model for the optimization of depth of penetration of weld bead geometry in pulsed gas metal arc welding process. The model is based on experimental data. The thickness of the plate, pulse frequency, wire feed rate, wire feed rate/travel speed ratio, and peak current have been considered as the process parameters to maximize the bead penetration depth. Optimization of process parameters was done using GA. The developed model is then compared with experimental results and it is found that the results obtained from genetic algorithm model are accurate. The optimal process parameters gave a value of 5.314 for depth of penetration which demonstrates an accuracy of 1.33 % and thus the effectiveness of the model presented. The obtained results help in selecting quickly the process parameters to achieve the desired quality. KeywordsGenetic algorithm, Pulsed GMA welding, Welding parameters, Depth of penetration, Regression mode I.

K. Manikya Kanti; P. Srinivasa Rao; G. Ranga Janardhana

155

Carbide Precipitation in Steel Weld Metals  

E-Print Network [OSTI]

Carbide Precipitation in Steel Weld Metals www.msm.cam.ac.uk/phase-trans #12 diffusion into austenite Carbon diffusion into austenite and carbide precipitation in ferrite Carbide precipitation from austenite CASE 2: elimination of carbides #12;#12;#12;0.110.090.070.050.03 0.2 0.4 0.6 0.8 1

Cambridge, University of

156

CRAD, Welding, Cutting and Brazing Assessment Plan  

Broader source: Energy.gov [DOE]

This assessment is to verify hot work requirements associated with welding, cutting, burning, brazing, grinding and other spark- or flame-producing operations have been implemented. Verify that the requirements implemented are appropriate for preventing loss of life and property from fire, and personal injury from contact with or exposure to molten metals, vapors, radiant energy, injurious rays and sparks.

157

Oxygen and Nitrogen Contamination During Arc Welding  

E-Print Network [OSTI]

) ) : ,- Oxygen and Nitrogen Contamination During Arc Welding T. W. Eagar Department of }faterials, mechanisms, and expected levels of oxygen and nitrogen contamination during gas tungsten arc, gas metal arc indicating the importance of dec9mposition of SiOz into silicon monoxide and oxygen are presented, indicating

Eagar, Thomas W.

158

Grain boundary defects initiation at the outer surface of dissimilar welds: Corrosion mechanism studies  

SciTech Connect (OSTI)

Dissimilar welds located on the primary coolant system of the French PWR plants exhibit grain boundary defects in the true austenitic zones of the first buttering layer. If grain boundaries reach the interface, they can extend to the martensitic band. Those defects are filled with compact oxides. In addition, the ferritic base metal presents some pits along the interface. Nowadays, three mechanisms are proposed to explain the initiation of those defects: stress corrosion cracking, intergranular corrosion and high temperature intergranular oxidation. This paper is dealing with the study of the mechanisms involved in the corrosion phenomenon. Intergranular corrosion tests performed on different materials show that only the first buttering layer, even with some {delta} ferrite, is sensitized. The results of stress corrosion cracking tests in water solutions show that intergranular cracking is possible on a bulk material representative of the first buttering layer. It is unlikely on actual dissimilar welds where the ferritic base metal protects the first austenitic layer by galvanic coupling. Therefore, the stress corrosion cracking assumption cannot explain the initiation of the defects in aqueous environment. The results of the investigations and of the corrosion studies led to the conclusion that the atmosphere could be the only possible aggressive environment. This conclusion is based on natural atmospheric exposure and accelerated corrosion tests carried out with SO{sub 2} additions in controlled atmosphere. They both induce a severe intergranular corrosion on true sensitized austenitic materials.

Bouvier, O. De; Yrieix, B. [Electricite De France, Moret Sur Loing (France). Research and Development Division

1995-12-31T23:59:59.000Z

159

Low cycle fatigue crack initiation life assessment of HY-100 undermatched weld  

SciTech Connect (OSTI)

An evaluation is conducted of several approaches to the prediction of low cycle fatigue crack initiation in HY-100 welds of an undermatched weldment. FEM analyses and experiments using various types of low cycle fatigue specimens were conducted and their results were compared with the results of such theoretical algorithms as Neuber's rule. A two-surface cyclic plasticity algorithm was implanted in a FEM code's user subroutine in order to simulate the material's cyclic stress-strain behavior under cyclic loading conditions; fatigue tests ranging from small, standard smooth specimens to notched cylindrical specimens with notch constraint were conducted for HY-100. 11 refs.

Wang, K.; Shah, R.; Yuan, D.; Kleinosky, M.J.

1993-01-01T23:59:59.000Z

160

Localized weld metal corrosion in stainless steel water tanks  

SciTech Connect (OSTI)

The rapidly developed leaks within the TFC and TFD tanks (LLNL groundwater treatment facilities) were caused by localized corrosion within the resolidified weld metal. The corrosion was initiated by the severe oxidation of the backsides of the welds which left the exposed surfaces in a condition highly susceptible to aqueous corrosion. The propagation of surface corrosion through the thickness of the welds occurred by localized corrosive attack. This localized attack was promoted by the presence of shielded aqueous environments provided by crevices at the root of the partial penetration welds. In addition to rapid corrosion of oxidized surfaces, calcium carbonate precipitation provided an additional source of physical shielding from the bulk tank environment. Qualification testing of alternate weld procedures showed that corrosion damage can be prevented in 304L stainless steel GTA welds by welding from both sides while preventing oxidation of the tank interior through the use of an inert backing gas such as argon. Corrosion resistance was also satisfactory in GMA welds in which oxidized surfaces were postweld cleaned by wire brushing and chemically passivated in nitric acid. Further improvements in corrosion resistance are expected from a Mo-containing grade of stainless steel such as type 316L, although test results were similar for type 304L sheet welded with type 308L filler metal and type 316L sheet welded with type 316L filler metal.

Strum, M.J.

1995-05-25T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

E-Print Network 3.0 - alloys laser welded Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

laser welded Search Powered by Explorit Topic List Advanced Search Sample search results for: alloys laser welded Page: << < 1 2 3 4 5 > >> 1 The influence of laser welding...

162

Development of New Ultrasonic Inspection Technique for Spot Welds with Matrix Arrayed Probe and SAFT  

Science Journals Connector (OSTI)

A portable type of 3D ultrasonic inspection system, named Matrixeye, was applied to the spot welds, in which a matrix-arrayed probe was used as a sensing unit, and the welding zone in the spot welds was visuali...

T. Ikeda; H. Karasawa; S. Matsumoto; S. Satonaka; C. Iwamoto

2006-05-01T23:59:59.000Z

163

Process-control in laser welding utilising optical signal oscillations  

SciTech Connect (OSTI)

The authors describe an optical sensor for process monitoring of Nd:YAG laser welding. This sensor detects the broadband radiation produced by the welding process, dividing it into broad spectral bands (designated as UV/visible and IR). Fourier analysis is used to investigate an oscillatory intensity modulation of the optical signals, believed to arise from a combination of keyhole and weld pool oscillations. The spectral content of the oscillations may be used to detect a fully open welding keyhole, and determine work-piece thickness in this welding regime. These oscillations have also been utilized in the construction of a seam tracking system which allows the authors to follow the seam of a lap-weld. Additional signal processing also allows optimum positioning of the laser spot.

Haran, F.M.; Hand, D.P.; Jones, J.D.C. [Heriot-Watt Univ., Edinburgh (United Kingdom)] [and others

1996-12-31T23:59:59.000Z

164

Industry standards catch up with in-service welding  

SciTech Connect (OSTI)

Welding onto a pipeline after it has been put into service, a practice commonly referred to as hot tap welding, is frequently required for several reasons. Repair sleeves are installed to reinforce areas of corrosion or mechanical damage, and branch connections are made for system modifications. There are often significant economic incentives to perform this welding without removing the system from service. Operations are maintained during welding and the pipe's contents are not vented into the atmosphere. Due to technological advances in in-service welding, industry needed an update to standards and recommended practices. This year, the American Petroleum Institute (API) hopes to meet that need. The 19th edition of API Standard 1104--Welding of Pipelines and Related Facilities, includes a new appendix that pertains to in-service welding. Appendix B, In-Service Welding, is intended to eventually replace API Recommended Practice 1107--Pipeline Maintenance Welding Practices. API 1107, which was introduced in 1966 and updated in 1987 and 1991, is intended to provide recommended practices for pipeline maintenance welding. The current third edition approached its mandatory five-year review in 1996 by the API-AGA Joint Committee on Oil and Gas Pipeline Field Welding Practices, which also maintains API 1104. The committee saw 11078 needed to reflect the updates that had been made to 1104 as well as the technological advances for in-service welding. To alleviate redundancy between the two documents, and to alleviate lag time between updates, the committee approved a proposal to update and incorporate requirements of API 1107 into an appendix of API 1104. In the meantime, the third edition of API 1107 was reapproved for another five-year review cycle.

Bruce, W.A.

1999-11-01T23:59:59.000Z

165

E-Print Network 3.0 - automatic welding Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Centre de mathmatiques Collection: Mathematics 34 Automated system for welding-based rapid prototyping Summary: Automated system for welding-based rapid prototyping Yu Ming...

166

Weld monitor and failure detector for nuclear reactor system  

DOE Patents [OSTI]

Critical but inaccessible welds in a nuclear reactor system are monitored throughout the life of the reactor by providing small aperture means projecting completely through the reactor vessel wall and also through the weld or welds to be monitored. The aperture means is normally sealed from the atmosphere within the reactor. Any incipient failure or cracking of the weld will cause the environment contained within the reactor to pass into the aperture means and thence to the outer surface of the reactor vessel where its presence is readily detected.

Sutton, Jr., Harry G. (Mt. Lebanon, PA)

1987-01-01T23:59:59.000Z

167

Fracture of welded aluminum thin-walled structures  

E-Print Network [OSTI]

A comprehensive methodology was developed in the thesis for damage prediction of welded aluminum thin-walled structures, which includes material modeling, calibration, numerical simulation and experimental verification. ...

Zheng, Li, Ph. D. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

168

Friction Stir Spot Welding of Advanced High Strength Steels II...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

II Friction Stir Spot Welding of Advanced High Strength Steels II 2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation...

169

SF 2001-WLD;CONTRACTOR WELDING, CUTTING AND BRAZING  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

closet, manhole sewer, confined space and activity. Example: Bldg 890 mechanical room steam line piping that runs thru ceiling space requires overhead welding: SF 2001-WLD...

170

Stress-corrosion cracking in BWR and PWR piping  

SciTech Connect (OSTI)

Intergranular stress-corrosion cracking of weld-sensitized wrought stainless steel piping has been an increasingly ubiquitous and expensive problem in boiling-water reactors over the last decade. In recent months, numerous cracks have been found, even in large-diameter lines. A number of potential remedies have been developed. These are directed at providing more resistant materials, reducing weld-induced stresses, or improving the water chemistry. The potential remedies are discussed, along with the capabilities of ultrasonic testing to find and size the cracks and related safety issues. The problem has been much less severe to date in pressurized-water reactors, reflecting the use of different materials and much lower coolant oxygen levels.

Weeks, R.W.

1983-07-01T23:59:59.000Z

171

Review of Dissimilar Metal Welding for the NGNP Helical-Coil Steam Generator  

SciTech Connect (OSTI)

The U.S. Department of Energy (DOE) is currently funding research and development of a new high temperature gas cooled reactor (HTGR) that is capable of providing high temperature process heat for industry. The steam generator of the HTGR will consist of an evaporator economizer section in the lower portion and a finishing superheater section in the upper portion. Alloy 800H is expected to be used for the superheater section, and 2.25Cr 1Mo steel is expected to be used for the evaporator economizer section. Dissimilar metal welds (DMW) will be needed to join these two materials. It is well known that failure of DMWs can occur well below the expected creep life of either base metal and well below the design life of the plant. The failure time depends on a wide range of factors related to service conditions, welding parameters, and alloys involved in the DMW. The overall objective of this report is to review factors associated with premature failure of DMWs operating at elevated temperatures and identify methods for extending the life of the 2.25Cr 1Mo steel to alloy 800H welds required in the new HTGR. Information is provided on a variety of topics pertinent to DMW failures, including microstructural evolution, failure mechanisms, creep rupture properties, aging behavior, remaining life estimation techniques, effect of environment on creep rupture properties, best practices, and research in progress to improve DMW performance. The microstructure of DMWs in the as welded condition consists of a sharp chemical concentration gradient across the fusion line that separates the ferritic and austenitic alloys. Upon cooling from the weld thermal cycle, a band of martensite forms within this concentration gradient due to high hardenability and the relatively rapid cooling rates associated with welding. Upon aging, during post weld heat treatment (PWHT), and/or during high temperature service, C diffuses down the chemical potential gradient from the ferritic 2.25Cr 1Mo steel toward the austenitic alloy. This can lead to formation of a soft C denuded zone near the interface on the ferritic steel, and nucleation and growth of carbides on the austenitic side that are associated with very high hardness. These large differences in microstructure and hardness occur over very short distances across the fusion line (~ 50 100 ?m). A band of carbides also forms along the fusion line in the ferritic side of the joint. The difference in hardness across the fusion line increases with increasing aging time due to nucleation and growth of the interfacial carbides. Premature failure of DMWs is generally attributed to several primary factors, including: the sharp change in microstructure and mechanical properties across the fusion line, the large difference in coefficient of thermal expansion (CTE) between the ferritic and austenitic alloys, formation of interfacial carbides that lead to creep cavity formation, and preferential oxidation of the ferritic steel near the fusion line. In general, the large gradient in mechanical properties and CTE serve to significantly concentrate the stress along the fusion where a creep susceptible microstructure has evolved during aging. Presence of an oxide notch can concentrate the stress even further. Details of the failure mechanism and the relative importance of each factor varies.

John N. DuPont

2010-03-01T23:59:59.000Z

172

Spot welding of steel and aluminum using insert sheet  

SciTech Connect (OSTI)

Automobile industries have been increasingly interested in the use of aluminum and thus joining of steel and aluminum becomes of importance. The joining of the two types of metal raises a problem of brittle welds caused by the formation of intermetallic compounds. The authors solved the problem by using an insert sheet. This paper deals with the resistance spot welding of steel and aluminum sheets using insert sheets. The insert sheet used in the present development was a steel/aluminum clad sheet of the 0.8 mm thickness with 50% steel and 50% aluminum. The clad sheet was produced by warm rolling of steel and aluminum with a direct resistance heating process. Steel to be warm rolled was of EDDQ of the 0.4 mm thickness and aluminum was of JIS A1050 of 0.6 mm thickness. The mechanical properties of the insert clad sheets were in between those of the steel sheets and the aluminum sheets, while the clad sheets showed much better formability than the aluminum sheets. Resistance spot welding was conducted for 0.8 mm thick EDDQ steel sheets and 1.0 mm thick aluminum alloy (AL-5.5%Mg) sheets under the welding force of 1.96 kN, welding current ranging between 4.2 and 20.1 kA, and welding time from 0.5 to 10 cycles. The steel was spot welded to the steel side of the insert sheet while the aluminum was welded to the aluminum side. What the authors investigated were the applicable welding current range, nugget diameter, tensile shear strength, U-tension strength, and macro- and microstructures. In conclusion, steel sheets can be spot welded to aluminum sheets without difficulty by using clad sheets as insert materials while the strength level of the dissimilar metal spot welds is close to that of aluminum joints.

Oikawa, H.; Saito, T.; Yoshimura, T. [and others

1994-12-31T23:59:59.000Z

173

WELDING RESEARCH JUNE 2007, VOL. 86-s170  

E-Print Network [OSTI]

resistance, Fe-Al weld cladding is susceptible to cracking due to hydrogen embrittlement at elevated aluminum cracking of FeAl and Fe3Al intermetallics is due to hydrogen embrittlement. In that work, the room investigated the effect of chromium on the hydrogen cracking susceptibility of Fe-Al weld cladding. The results

DuPont, John N.

174

NDE and DE of PWSCC Found in the J-Groove Weld of a Removed-From-Service Control Rod Drive Mechanism  

SciTech Connect (OSTI)

Studies conducted at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington focused on assessing the effectiveness of nondestructive examination (NDE) techniques for inspecting control rod drive mechanism (CRDM) nozzles and J-groove weldments. The primary objective of this work is to provide information to the United States Nuclear Regulatory Commission (US NRC) on the effectiveness of NDE methods as related to the in-service inspection of CRDM nozzles and J-groove weldments, and to enhance the knowledge base of primary water stress corrosion cracking (PWSCC) through destructive characterization of the CRDM assemblies. Two CRDM assemblies were removed from service, decontaminated, and then used in a series of laboratory NDE and DE measurements; this report addresses the following questions: 1) What did each NDE technique detect?, 2) What did each NDE technique miss?, 3) How accurately did each NDE technique characterize the detected flaws?, and finally 4) What were the basis for the NDE techniques performance? Two CRDM assemblies including the CRDM nozzle, the J-groove weld, buttering, and a portion of the ferritic head material were selected for this study. This paper focuses on a CRDM assembly that contained suspected PWSCC, based on in-service inspection data and through-wall leakage. The laboratory NDE measurements used to examine the CRDM assembly followed standard industry techniques for conducting in-service inspections of CRDM nozzles and the crown of the J-groove welds and buttering. These techniques included eddy current testing, time of flight diffraction ultrasound, and penetrant testing. In addition, other laboratory-based NDE methods were employed to conduct inspections of the CRDM assembly with particular emphasis on inspecting the J-groove weld and buttering. These techniques included volumetric ultrasonic inspection of the J-groove weld metal, visual testing via replicant material of the J-groove weld and high resolution photography of the J-groove weld crown and buttering. The results from these NDE studies were used to guide the development of the destructive characterization plan. The NDE studies found several crack-like indications. The NDE and DE studies determined that one of these was a through-weld radially-oriented PWSCC crack in the wetted surface of the J-groove weld, located at the transition point between the weld and the buttering. The crack was 6 mm long on the surface and quickly grew to 25 mm long at a depth of 8 mm, covering the length of the weld between the penetration tube and the carbon steel. The NDE studies found that only ET was able to detect the through-weld crack. The crack was oriented poorly for the ultrasonic testing, and was too tight for accurate PT or VT. The ET voltage response of the flaw was 30% that of a deep EDM notch. The DE performed on the crack consisted of slicing the crack into thin sections, polishing the sections, and then using optical and scanning electron microscopy (SEM) to characterize the crack. DE shows the crack was PWSCC and that it initiated on the wetted surface, grew and expanded through the weld metal, and exited into the annulus. The SEM examinations showed the crack followed the weld grain boundaries as it progressed through the weld. The crack was branched and discontinuous along its length.

Cumblidge, Stephen E.; Doctor, Steven R.; Schuster, George J.; Harris, Rob; Crawford, Susan L.; Seffens, Rob J.; Toloczko, Mychailo B.; Bruemmer, Stephen M.

2008-01-01T23:59:59.000Z

175

CRAD, Welding, Cutting and Brazing Assessment Plan | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Welding, Cutting and Brazing Assessment Plan Welding, Cutting and Brazing Assessment Plan CRAD, Welding, Cutting and Brazing Assessment Plan Performance Objective: This assessment is to verify hot work requirements associated with welding, cutting, burning, brazing, grinding and other spark- or flame-producing operations have been implemented. Verify that the requirements implemented are appropriate for preventing loss of life and property from fire, and personal injury from contact with or exposure to molten metals, vapors, radiant energy, injurious rays and sparks. Criteria: Establish designated area in which routine and repetitive welding, cutting, and other spark- or flame producing operations are conducted [1910.252(a)(2)(iv),1910.252(a)(2)(vi)(A), 1910.252(a)(2)(xv), General Requirements].

176

Pressure Resistance Welding of High Temperature Metallic Materials  

SciTech Connect (OSTI)

Engineers from the Idaho National Laboratory (INL) have demonstrated an innovative method for seal or pinch welding stainless steel tubing. Sometimes a tube has fuel or contamination that must be contained, or the tube needs to be shortened or cut for handling, and the tube needs to have a guaranteed sealed weld that is both quick and easy. This technique was demonstrated in a laboratory using a resistance welding system with specially designed electrodes to ensure a tube end is seal welded or if a long tube is to be shortened, the severed ends are seal welded. The unique electrodes design is integral to achieving the sealed ends. This process could readily be adapted for robotic--remote handling or for contact handling in a glovebox or hood.

Larry Zirker; Craig Tyler

2010-08-01T23:59:59.000Z

177

F i W ldi PFusion Welding -Processes ME 6222: Manufacturing Processes and Systems  

E-Print Network [OSTI]

Overview · Types of fusion welding ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 3 #12Summary · Types of fusion welding ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 25 #12.S. Colton © GIT 2009 1 #12;Fusion weldingFusion welding · Intimate interfacial contact by using a liquid

Colton, Jonathan S.

178

17 The Intelligent Welding Gun: Augmented Reality for Experimental Vehicle Construction  

E-Print Network [OSTI]

17 The Intelligent Welding Gun: Augmented Reality for Experimental Vehicle Construction Florian presents the prototypical design and implementation of an Intelligent Welding Gun to help welders is the Intelligent Welding Gun ­ a regular welding gun with a display attachment, a few buttons for user in

Bruegge, Bernd

179

Numerical simulations of welds of thick steel pieces of interest for the thermonuclear fusion ITER machine  

E-Print Network [OSTI]

Numerical simulations of welds of thick steel pieces of interest for the thermonuclear fusion ITER machine

Carmignani, B

2005-01-01T23:59:59.000Z

180

The effect of iron dilution on strength of nickel/steel and Monel/steel welds  

SciTech Connect (OSTI)

The weld strength, as a function of iron content, for nickel/steel and Monel/steel welds was determined. Samples were prepared using a Gas Metal Arc (GMAW) automatic process to weld steel plate together with nickel or Monel to produce a range of iron contents typical of weld compositions. Tensile specimens of each iron content were tested to obtain strength and ductility measurements for that weld composition. Data indicate that at iron contents of less than 20% iron in a nickel/steel weld, the weld fails at the weld interface, due to a lack of fusion. Between 20% and 35% iron, the highest iron dilution that could be achieved in a nickel weld, the welds were stronger than the steel base metal. This indicates that a minimum amount of iron dilution (20%) is necessary for good fusion and optimum strength. On the other hand for Monel/steel welds, test results showed that the welds had good strength and integrity between 10% and 27% iron in the weld. Above 35% iron, the welds have less strength and are more brittle. The 35% iron content also corresponds to the iron dilution in Monel welds that has been shown to produce an increase in corrosion rate. This indicates that the iron dilution in Monel welds should be kept below 35% iron to maximize both the strength and corrosion resistance. 2 refs., 6 figs., 3 tabs.

Fout, S.L.; Wamsley, S.D.

1983-03-28T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Quiz # 7, STAT 383, Prof. Suman Sanyal, April 8, 2009 (Q2, Page 354) To decide whether the pipe welds in a nuclear power plant meet  

E-Print Network [OSTI]

welds in a nuclear power plant meet specifications, a random sample of welds is to be selected : µ nuclear power plants is to determine if welds

Sanyal, Suman

182

Initial Development in Joining of ODS Alloys Using Friction Stir Welding  

SciTech Connect (OSTI)

Solid-state welding of oxide-dispersion-strengthened (ODS) alloy MA956 sheets using friction stir welding (FSW) was investigated. Butt weld was successfully produced. The weld and base metals were characterized using optical microscopy, scanning electronic microscopy, transmission electronic microscopy, and energy dispersion x-ray spectrum. Microhardness mapping was also conducted over the weld region. Analyses indicate that the distribution of the strengthening oxides was preserved in the weld. Decrease in microhardness of the weld was observed but was insignificant. The preliminary results seem to confirm the envisioned feasibility of FSW application to ODS alloy joining. For application to Gen IV nuclear reactor heat exchanger, further investigation is suggested.

Ren, Weiju [ORNL; Feng, Zhili [ORNL

2007-08-01T23:59:59.000Z

183

Influence of Aluminum Content on Grain Refinement and Strength of AZ31 Magnesium GTA Weld Metal  

SciTech Connect (OSTI)

The goal is to characterize the effect of Al content on AZ31 weld metal, the grain size and strength, and examine role of Al on grain refinement. The approach is to systematically vary the aluminum content of AZ31 weld metal, Measure average grain size in weld metal, and Measure cross-weld tensile properties and hardness. Conclusions are that: (1) increased Al content in AZ31 weld metal results in grain refinement Reason: higher undercooling during solidification; (2) weld metal grain refinement resulted in increased strength & hardness Reason: grain boundary strengthening; and (3) weld metal strength can be raised to wrought base metal levels.

Babu, N. Kishore [Singapore Institute of Manufacturing Technology; Cross, Carl E. [Los Alamos National Laboratory

2012-06-28T23:59:59.000Z

184

S&TR | March/April 2008: Standardizing the Art of Electron-Beam Welding  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Standardizing the Art of Electron-Beam Welding. Standardizing the Art of Electron-Beam Welding. WELDED materials are an integral part of everyday life. Appliances, cars, and bridges are all made by welding materials together. But not all welds are created equal. Welding methods vary in complexity, time, and cost, depending on a product's requirements and purpose. In electron-beam (EBeam) welding, an electron beam generated in a vacuum creates a fusing heat source that can unite almost any metals. This method produces deep welds without adding excessive heat that can adversely affect the properties of the surrounding metal. In the nuclear energy and aerospace industries, electron-beam welding is preferred for manufacturing high-value welds-those in which defects cannot be tolerated. The Department of Energy's (DOE's) nuclear weapons

185

Friction stir welding and processing of oxide dispersion strengthened (ODS) alloys  

DOE Patents [OSTI]

A method of welding including forming a filler material of a first oxide dispersoid metal, the first oxide dispersoid material having first strengthening particles that compensate for decreases in weld strength of friction stir welded oxide dispersoid metals; positioning the filler material between a first metal structure and a second metal structure each being comprised of at least a second oxide dispersoid metal; and friction welding the filler material, the first metal structure and the second metal structure to provide a weld.

Ren, Weiju

2014-11-11T23:59:59.000Z

186

FITNESS-FOR-SERVICE ASSESSMENT FOR A RADIOACTIVE WASTE TANK THAT CONTAINS STRESS CORROSION CRACKS  

SciTech Connect (OSTI)

Radioactive wastes are confined in 49 underground storage tanks at the Savannah River Site. The tanks are examined by ultrasonic (UT) methods for thinning, pitting, and stress corrosion cracking in order to assess fitness-for-service. During an inspection in 2002, ten cracks were identified on one of the tanks. Given the location of the cracks (i.e., adjacent to welds, weld attachments, and weld repairs), fabrication details (e.g., this tank was not stress-relieved), and the service history the degradation mechanism was stress corrosion cracking. Crack instability calculations utilizing API-579 guidance were performed to show that the combination of expected future service condition hydrostatic and weld residual stresses do not drive any of the identified cracks to instability. The cracks were re-inspected in 2007 to determine if crack growth had occurred. During this re-examination, one indication that was initially reported as a 'possible perpendicular crack <25% through wall' in 2002, was clearly shown not to be a crack. Additionally, examination of a new area immediately adjacent to other cracks along a vertical weld revealed three new cracks. It is not known when these new cracks formed as they could very well have been present in 2002 as well. Therefore, a total of twelve cracks were evaluated during the re-examination. Comparison of the crack lengths measured in 2002 and 2007 revealed that crack growth had occurred in four of the nine previously measured cracks. The crack length extension ranged from 0.25 to 1.8 inches. However, in all cases the cracks still remained within the residual stress zone (i.e., within two to three inches of the weld). The impact of the cracks that grew on the future service of Tank 15 was re-assessed. API-579 crack instability calculations were again performed, based on expected future service conditions and trended crack growth rates for the future tank service cycle. The analysis showed that the combined hydrostatic and weld residual stresses do not drive the identified cracks to instability. This tank expected to be decommissioned in the near future. However, if these plans are delayed, it was recommended that a third examination of selected cracks in the tank be performed in 2014.

Wiersma, B; James Elder, J; Rodney Vandekamp, R; Charles Mckeel, C

2009-04-23T23:59:59.000Z

187

POTENTIAL FOR STRESS CORROSION CRACKING OF A537 CARBON STEEL NUCLEAR WASTE TANKS CONTAINING HIGHLY CAUSTIC SOLUTIONS  

SciTech Connect (OSTI)

The evaporator recycle streams of nuclear waste tanks may contain waste in a chemistry and temperature regime that exceeds the current corrosion control program, which imposes temperature limits to mitigate caustic stress corrosion cracking (CSCC). A review of the recent service history found that two of these A537 carbon steel tanks were operated in highly concentrated hydroxide solution at high temperature. Visual inspections, experimental testing, and a review of the tank service history have shown that CSCC has occurred in uncooled/un-stress relieved tanks of similar construction. Therefore, it appears that the efficacy of stress relief of welding residual stress is the primary corrosion-limiting mechanism. The objective of this experimental program is to test A537 carbon steel small scale welded U-bend specimens and large welded plates (30.48 x 30.38 x 2.54 cm) in a caustic solution with upper bound chemistry (12 M hydroxide and 1 M each of nitrate, nitrite, and aluminate) and temperature (125 C). These conditions simulate worst-case situations in these nuclear waste tanks. Both as-welded and stress-relieved specimens have been tested. No evidence of stress corrosion cracking was found in the U-bend specimens after 21 days of testing. The large plate test was completed after 12 weeks of immersion in a similar solution at 125 C except that the aluminate concentration was reduced to 0.3 M. Visual inspection of the plate revealed that stress corrosion cracking had not initiated from the machined crack tips in the weld or in the heat affected zone. NDE ultrasonic testing also confirmed subsurface cracking did not occur. Based on these results, it can be concluded that the environmental condition of these tests was unable to develop stress corrosion cracking within the test periods for the small welded U-bends and for the large plates, which were welded with an identical procedure as used in the construction of the actual nuclear waste tanks in the 1960s. The absence of evidence of stress corrosion cracking and general corrosion in the laboratory-scaled specimens indicate that this type of nuclear waste tank is not susceptible to highly caustic solutions up to 12 M hydroxide at 125 C when sufficient nitrite inhibitor is present.

Lam, P.; Stripling, C.; Fisher, D.; Elder, J.

2010-04-26T23:59:59.000Z

188

Reduce Stress!  

Broader source: Energy.gov (indexed) [DOE]

Stress! Stress! x Take a break every hour. Do some relaxation or stretching exercises or talk with someone about topics unrelated to work. Give your body and mind a rest. x Massage your hands and forearms several times a day with a vitamin E lotion. The massage will improve circulation and break up adhesions. Since you can't touch a keyboard until the lotion is absorbed, it also enforces a good break. x Massage the muscles in your neck working your way down from the skull to the shoulders, applying more force to the larger muscles as you go down. x Periodically evaluate your environment for ways to reduce stress. Try to keep your desk uncluttered so you can always find things. Make sure programs are set up correctly on the computer, and see if you can use a macro program to reduce

189

Mechanical and metallurgical properties of MMC friction welds  

SciTech Connect (OSTI)

The mechanical and metallurgical properties of similar and dissimilar welds involving aluminum-based metal matrix composite (MMC) base material were investigated using factorial experimentation. The test materials comprised aluminum-based alloy 6061/Al{sub 2}O{sub 3} (W6A.10A-T6), aluminum Alloy 6061-T6 and AISI 304 stainless steel. Notch tensile strength increased when high friction pressures were employed during MMC/MMC, MMC/Alloy 6061, MMC/AISI 304 stainless steel and Alloy 6061/Alloy 6061 friction welding. In MMC/Alloy 6061 welds, notch tensile strength also increased when high forging pressures were employed. Applied oxide films on both the MMC and AISI stainless steel substrates had a markedly detrimental effect on dissimilar weld mechanical properties. The optimum notch tensile strength properties were produced when high friction pressure values were applied during dissimilar MMC/AISI 304 stainless steel welding. High friction pressure had two beneficial effects, i.e., it decreased the thickness of the FeAl{sub 3} intermetallic film and it promoted disruption and dispersal of oxide films at the joint interface. In direct contrast, the presence of thick anodized oxide films on the MMC substrate surface prior to friction welding had no observable influence on MMC/MMC weld mechanical properties.

Li, Z.; Maldonado, C.; North, T.H. [Univ. of Toronto, Ontario (Canada). Dept. of Metallurgy and Materials Science; Altshuller, B. [Alcan R and D Labs., Kingston, Ontario (Canada)

1997-09-01T23:59:59.000Z

190

Thermal and molecular investigation of laser tissue welding  

SciTech Connect (OSTI)

Despite the growing number of successful animal and human trials, the exact mechanisms of laser tissue welding remain unknown. Furthermore, the effects of laser heating on tissue on the molecular scale are not fully understood. To address these issues, a multi-front attack oil both extrinsic (solder/patch mediated) and intrinsic (laser only) tissue welding was launched using two-color infrared thermometry, computer modeling, weld strength assessment, biochemical assays, and vibrational spectroscopy. The coupling of experimentally measured surface temperatures with the predictive numerical simulations provided insight into the sub-surface dynamics of the laser tissue welding process. Quantification of the acute strength of the welds following the welding procedure enabled comparison among trials during an experiment, with previous experiments, and with other studies in the literature. The acute weld integrity also provided an indication of tile probability of long-term success. Molecular effects induced In the tissue by laser irradiation were investigated by measuring tile concentrations of specific collagen covalent crosslinks and characterizing the Fourier-Transform infrared (FTIR) spectra before and after the laser exposure.

Small, W., IV

1998-06-01T23:59:59.000Z

191

New development activities in the field of wet welding  

SciTech Connect (OSTI)

The Wet Welding process has now become an interesting alternative repair process due to its high flexibility, its low investment costs and its high versatility. However, due to the prior bad reputation of the in former times achievable low weldment quality, due to extremely high hardness, high porosity, high hydrogen contamination and in combination with this high cracking susceptibility the wet welding process nowadays requires further activities to improve its reputation and credibility. New acceptance criteria, more detailed information on the achievable weldment quality and especially the development of life prediction data for wet welded components are now required. Advanced testing methods are necessary, additional design criteria are to be developed and achievable weldment quality data are to be included in acknowledged and approved standards and recommendations. Only by the provision of such data the credibility of the process and the problem of quality assurance for wet welded joints can be improved. In two comprehensive projects, sponsored by the European Community under the Thermie Programme, process development and new testing procedures have bene procured and are still under progress to generate the required data and new design criteria for the future application of the wet welding process to main components of offshore structures. The water depths in the range of 50 to 100 msw have been selected for the application of the wet welding process to structural components, as these depths include that range of application in which this process can become competitive to the hyperbaric dry welding process. The international trend to mechanize and automate the hyperbaric welding processes in dry environments can even be completed by the application of a semiautomatic wet welding process, which has already shown very promising results. This process is applicable to mechanized systems (e.g. to a wet robot system).

Szelagowski, P.; Osthus, V. [GKSS Research Center, Geesthacht (Germany); Petershagen, H.; Pohl, R. [Univ. Hamburg (Germany). Inst. fuer Schiffbau; Lafaye, G. [Stolt Comex Seaway, S.A., Marseille (France)

1995-12-31T23:59:59.000Z

192

Dissimilar friction welding of titanium alloys to alloy 718  

SciTech Connect (OSTI)

The design of advanced, high-performance gas-turbine engines will require the utilization of elevated-temperature titanium-based materials, including conventional alloys, titanium aluminides, and titanium metal-matrix composites. The most efficient utilization of these materials in the engine compressor section would be achieved by directly joining these materials to existing nickel-base superalloys, such as Alloy 718. To date, the dissimilar welding of titanium alloys to nickel-based alloys has not been common practice because intermetallic compounds form in the weld and cause embrittlement. Special welding techniques must be developed to inhibit this compound formation and to provide high strength welds. In this investigation, a friction welding process was developed for joining titanium alloys (Ti-6Al-2Sn-4Zr-2Mo and Ti-6Al-4V) to nickel-based superalloy Alloy 718. An interlayer system comprised of copper and niobium sheet layers was employed as a diffusion barrier and weld deformation enhancer. A postweld heat treatment (PWHT, 700{degrees}C for 20 min in vacuum) under axial pressure (Ksi) was used to improve the joint strength consistency. The following conclusions can be drawn from this investigation: (1) A friction welding technique has been developed for joining titanium alloys (Ti-6Al-2Sn-4Zr-2Mo and Ti-6Al-4V) to Alloy 718 using an interlayer system of niobium and copper. Joint strengths averaging approximately 50 Ksi were achieved. (2) Deformation was concentrated in the interlayers, especially the copper interlayer, during friction welding. Increased reduction in length (RIL) during friction welding resulted in a decrease in the interlayer thicknesses. (3) The EDS results showed that the niobium and copper interlayers prevent interdiffusion between the two parent metals, producing formation of detrimental phases.

Kuo, M.; Albright, C.E.; Baeslack, W.A. III

1994-12-31T23:59:59.000Z

193

Local mechanical properties of Alloy 82/182 dissimilar weld joint between SA508 Gr.1a and F316 SS at RT and 320C  

SciTech Connect (OSTI)

This paper presents the variations of local mechanical and microstructural properties in dissimilar metal weld joints consisting of the SA508 Gr.1a ferritic steel, Alloy 82/182 filler metal, and F316 austenitic stainless steel. Flat or round tensile specimens and transmission electron microscopy disks were taken from the base metals, welds, and heat-affected zones (HAZ) of the joints and tested at room temperature (RT) and/or at 320 C. The tensile test results indicated that the mechanical property was relatively uniform within each material zone, but varied considerably between different zones. Further, significant variations were observed both in the austenitic HAZ of F316 SS and in the ferritic HAZ of SA508 Gr.1a. The yield stress (YS) of the weld metal was under-matched with respect to the HAZs of SA508 Gr.1a and F316 SS by 0.78 to 0.92, although the YS was over-matched with respect to both base metals. The minimum ductility occurred in the HAZ of SA508 Gr.1 at both test temperatures. The plastic instability stress also varied considerably in the weld joints, with minimum values occurring in the SA508 Gr.1a base metal at RT and in the HAZ of F316 SS at 320 C, suggesting that the probability of ductile failure caused by a unstable deformation at the Alloy 82/182 buttering layer is low. Within the HAZ of SA508 Gr.1a, the gradient of the YS and ultimate tensile strength (UTS) was significant, primarily because of the different microstructures produced by the phase transformation during the welding process. The increment of YS was unexpectedly high in the HAZ of F316 SS, which was explained by the strain hardening induced by a strain mismatch between the weldment and the base metal. This was confirmed by the transmission electron micrographs showing high dislocation density in the HAZ.

Byun, Thak Sang [ORNL; Kim, Jin Weon [ORNL

2009-01-01T23:59:59.000Z

194

Welding fixture for nuclear fuel pin cladding assemblies  

DOE Patents [OSTI]

A welding fixture for locating a driver sleeve about the open end of a nuclear fuel pin cladding. The welding fixture includes a holder provided with an open cavity having shoulders for properly positioning the driver sleeve, the end cap, and a soft, high temperature resistant plastic protective sleeve that surrounds a portion of the end cap stem. Ejected contaminant particles spewed forth by closure of the cladding by pulsed magnetic welding techniques are captured within a contamination trap formed in the holder for ultimate removal and disposal of contaminating particles along with the holder.

Oakley, David J. (Richland, WA); Feld, Sam H. (West Richland, WA)

1986-01-01T23:59:59.000Z

195

OPTIMIZATION STUDY FOR FILL STEM MANUFACTURINGAND PINCH WELD PROCESSING  

SciTech Connect (OSTI)

A statistically designed experiment was conducted as part of a six sigma project for Fill Stem Manufacturing and Pinch Weld Processing. This multi-year/multi-site project has successfully completed a screening study and used those results as inputs to this optimization study. Eleven welds were made using fairly tight current and cycle range. The welds demonstrate increased burst strength, longer closure length, more net displacement, and improved bond rating with increased current. However, excessive melting remains a concern from a processing viewpoint and may cause adverse metallurgical interactions. Therefore, the highest current levels specified cannot be utilized. A Validation Study is proposed for the Defense Programs Inert Facility.

Korinko, P; Karl Arnold, K

2006-09-06T23:59:59.000Z

196

Welding for testability: An approach aimed at improving the ultrasonic testing of thick-walled austenitic and dissimilar metal welds  

SciTech Connect (OSTI)

Austenitic and dissimilar welds in thick walled components show a coarse grained, dendritic microstructure. Therefore, ultrasonic testing has to deal with beam refraction, scattering and mode conversion effects. As a result, the testing techniques typically applied for isotropic materials yield dissatisfying results. Most approaches for improvement of ultrasonic testing have been based on modeling and improved knowledge of the complex wave propagation phenomena. In this paper, we discuss an alternative approach: is it possible to use a modified welding technology which eliminates the cause of the UT complications, i.e. the large-grained structure of the weld seams? Various modification parameters were tested, including: TIG current pulsing, additional DC and AC magnetic fields, and also additional external vibrations during welding. For all welds produced under different conditions, the grain structure of the weld seam was characterized by optical and GIUM microstructure visualizations on cross sections, wave field propagation measurements, and ultrasonic tests of correct detectability of flaws. The mechanical properties of the welds were also tested.

Wagner, Sabine; Dugan, Sandra [Materials Testing Institute University of Stuttgart (MPA), Pfaffenwaldring 32, 70569 Stuttgart (Germany); Barth, Martin; Schubert, Frank; Khler, Bernd [Fraunhofer Institute for Nondestructive Testing, Dresden Branch (IZFP-D), Maria-Reiche-Str. 2, 01109 Dresden (Germany)

2014-02-18T23:59:59.000Z

197

Weld-Windsor 115-kV Transmission Line Project, Weld County, Colorado  

SciTech Connect (OSTI)

The Western Area Power Administration is proposing to rebuild a 3.0 mile segment of the existing Flatiron-Weld 115-kV transmission line in Weld County. The line would be reconductored with new conductor on new wood pole double circuit structures. The new structures would support a double circuit transmission line configuration. The first circuit would be owned by Western and the second by Public Service Company of Colorado (PSCO). Alternatives considered included no action, constructing PSCO`s circuit on new right-of-way, and reconductoring Western`s existing line on the same structures. The proposed action was selected because it provided an opportunity to share structures with PSCO and, overall, would minimize costs and environmental impacts. The environmental assessment identifies minor effects on existing natural or human resources and minor benefits for agricultural operations.

NONE

1996-05-01T23:59:59.000Z

198

Friction Stir Spot Welding of Advanced High Strength Steels ...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. lm14grant.pdf More Documents & Publications Friction Stir Spot Welding of Advanced High...

199

Microstructural study of high energy density dissimilar metal welds  

SciTech Connect (OSTI)

Electron microscopy analysis of two different CO/sub 2/ laser welded dissimilar metal combinations revealed the presence of minor constituents which could be attributed to terminal solidification events. In the case of the 15-5 PH/HP 9-4-20 welds, a NbC/austenite eutectic-type constituent was identified, which accounted for the observed fusion-zone hot cracks in these welds. The identity of the interdendritic constituent first observed optically by Patterson and Milewski/sup 9/ in 304L/625 GTA welds has been confirmed as Laves phase. It was further determined that this phase is enriched in Mo and Nb relative to the austenite matrix.

Cieslak, M.J.; Hills, C.R.; Headley, T.J.

1986-01-01T23:59:59.000Z

200

Friction Stir Spot Welding of Advanced High Strength Steels ...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Steels (AHSS) Friction Stir Spot Welding of Advanced High Strength Steels (AHSS) Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review 2008 on February...

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

SAFT Imaging of Transverse Cracks in Austenitic and Dissimilar Welds  

Science Journals Connector (OSTI)

Up to now there is no sufficient technique to detect transverse cracks in austenitic and dissimilar welds which recently are of increasing interest in the integrity surveillance of nuclear power plants as well as...

Christian Hhne; Sanjeevareddy Kolkoori

2013-03-01T23:59:59.000Z

202

Weld solidification cracking in 304 to 304L stainless steel  

SciTech Connect (OSTI)

A series of annulus welds were made between 304 and 304L stainless steel coaxial tubes using both pulsed laser beam welding (LBW) and pulsed gas tungsten arc welding (GTAW). In this application, a change in process from pulsed LBW to pulsed gas tungsten arc welding was proposed to limit the possibility of weld solidification cracking since weldability diagrams developed for GTAW display a greater range of compositions that are not crack susceptible relative to those developed for pulsed LBW. Contrary to the predictions of the GTAW weldability diagram, cracking was found. This result was rationalized in terms of the more rapid solidification rate of the pulsed gas tungsten arc welds. In addition, for the pulsed LBW conditions, the material compositions were predicted to be, by themselves, 'weldable' according to the pulsed LBW weldability diagram. However, the composition range along the tie line connecting the two compositions passed through the crack susceptible range. Microstructurally, the primary solidification mode (PSM) of the material processed with higher power LBW was determined to be austenite (A), while solidification mode of the materials processed with lower power LBW apparently exhibited a dual PSM of both austenite (A) and ferrite-austenite (FA) within the same weld. The materials processed by pulsed GT A W showed mostly primary austenite solidification, with some regions of either primary austenite-second phase ferrite (AF) solidification or primary ferrite-second phase austenite (FA) solidification. This work demonstrates that variations in crack susceptibility may be realized when welding different heats of 'weldable' materials together, and that slight variations in processing can also contribute to crack susceptibility.

Hochanadel, Patrick W [Los Alamos National Laboratory; Lienert, Thomas J [Los Alamos National Laboratory; Martinez, Jesse N [Los Alamos National Laboratory; Martinez, Raymond J [Los Alamos National Laboratory; Johnson, Matthew Q [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

203

Dissimilar-metal weld failures in boiler tubing  

SciTech Connect (OSTI)

Both ferritic heat-resisting steels and austenitic stainless steels are used for fossil-fired boilers for central power stations. The use of these two different types of materials within the system leads to the need for a dissimilar-metal weld transition joint. Increased cyclic operation of boilers has led to a rash of failures in welds between dissimilar metals; studies have identified the causes, and improved nondestructive testing techniques permit early identification of problem areas.

Klueh, R.L.

1984-02-01T23:59:59.000Z

204

Weld solidification cracking in 304 to 204L stainless steel  

SciTech Connect (OSTI)

A series of annulus welds were made between 304 and 304L stainless steel coaxial tubes using both pulsed laser beam welding (LBW) and pulsed gas tungsten arc welding (GTAW). In this application, a change in process from pulsed LBW to pulsed gas tungsten arc welding was proposed to limit the possibility of weld solidification cracking since weldability diagrams developed for GTAW display a greater range of compositions that are not crack susceptible relative to those developed for pulsed LBW. Contrary to the predictions of the GTAW weldability diagram, cracking was found.This result was rationalized in terms of the more rapid solidification rate of the pulsed gas tungsten arc welds. In addition, for the pulsed LBW conditions, the material compositions were predicted to be, by themselves, 'weldable' according to the pulsed LBW weldability diagram. However, the composition range along the tie line connecting the two compositions passed through the crack susceptible range. Microstructurally, the primary solidification mode (PSM) of the material processed with higher power LBW was determined to be austenite (A), while solidification mode of the materials processed with lower power LBW apparently exhibited a dual PSM of both austenite (A) and ferrite-austenite (FA) within the same weld. The materials processed by pulsed GTAW showed mostly primary austenite solidification, with some regions of either primary austenite-second phase ferrite (AF) solidification or primary ferrite-second phase austenite (FA) solidification. This work demonstrates that variations in crack susceptibility may be realized when welding different heats of 'weldable' materials together, and that slight variations in processing can also contribute to crack susceptibility.

Hochanadel, Patrick W [Los Alamos National Laboratory; Lienert, Thomas J [Los Alamos National Laboratory; Martinez, Jesse N [Los Alamos National Laboratory; Johnson, Matthew Q [Los Alamos National Laboratory

2010-09-15T23:59:59.000Z

205

Effects of Post-Weld Heat Treatment on the Mechanical Properties of Similar- and Dissimilar-Alloy Friction Stir Welded Blanks  

SciTech Connect (OSTI)

Friction stir welding is a solid state joining process with relatively low welding temperatures. Nevertheless, the mechanical properties of friction stir welded blanks are degraded after welding. Indeed, both strength and ductility of the welds are decreased after welding. Often, the resulting friction stir welded blanks need to be formed to their final structural shape. Therefore, the formability of friction stir welded blanks is of primary importance in the manufacturing of structural parts. This paper studies how the mechanical properties and particularly formability of friction stir welded blanks can be improved by applying a post weld heat treatment. Two aluminum alloys from 2000 and 7000 series, namely 2024-T3 and 7075-T6, are selected for the study. The sheet thickness of both materials is 2,0 mm. The selected alloys are welded in three configurations: 2024-T3 and 2024-T3, 7075-T6 and 7075-T6, and 2024-T3 and 7075-T6. The resulting welds are naturally aged for a few months. Three sets of standard dog bone shape tensile test specimens are then machined from the welds. The first set of the specimens is tested without any heat treatment. The second set of the specimens is solution heat treated and quenched before testing. The third set of the specimens is solution heat treated, quenched, and naturally aged for a week before testing. The mechanical properties of the three different sets of specimens are compared with each other. It is shown that careful selection of post weld heat-treatment can greatly improve the formability of friction stir welded blanks.

Zadpoor, Amir Abbas [Materials Innovation Institute (M2i), Mekelweg 2, Delft 2628CD (Netherlands); Faculty of Aerospace Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2629HS (Netherlands); Sinke, Jos [Faculty of Aerospace Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2629HS (Netherlands)

2011-01-17T23:59:59.000Z

206

Accurate modelling of anisotropic effects in austenitic stainless steel welds  

SciTech Connect (OSTI)

The ultrasonic inspection of austenitic steel welds is challenging due to the formation of highly anisotropic and heterogeneous structures post-welding. This is due to the intrinsic crystallographic structure of austenitic steel, driving the formation of dendritic grain structures on cooling. The anisotropy is manifested as both a steering of the ultrasonic beam and the back-scatter of energy due to the macroscopic granular structure of the weld. However, the quantitative effects and relative impacts of these phenomena are not well-understood. A semi-analytical simulation framework has been developed to allow the study of anisotropic effects in austenitic stainless steel welds. Frequency-dependent scatterers are allocated to a weld-region to approximate the coarse grain-structures observed within austenitic welds and imaged using a simulated array. The simulated A-scans are compared against an equivalent experimental setup demonstrating excellent agreement of the Signal to Noise (S/N) ratio. Comparison of images of the simulated and experimental data generated using the Total Focusing Method (TFM) indicate a prominent layered effect in the simulated data. A superior grain allocation routine is required to improve upon this.

Nowers, O. D.; Duxbury, D. J. [NDE Research, Support and Development, Rolls-Royce Marine, Derby, PO BOX 2000, DE21 7XX (United Kingdom); Drinkwater, B. W. [Department of Mechanical Engineering, University Walk, University of Bristol, Bristol BS8 1TR (United Kingdom)

2014-02-18T23:59:59.000Z

207

Set up an Arc Welding Code with Enthalpy Method in Upwind Scheme  

SciTech Connect (OSTI)

In this study, a numerical code with enthalpy method in upwind scheme is proposed to estimate the distribution of thermal stress in the molten pool, which is primarily determined by the type of the input power and travel speed of heating source. To predict the cracker deficit inside the workpiece, a simulated program satisfying the diagonal domination and Scarborough criterion provides a stable iteration. Meantime, an experimental performance, operated by robot arm 'DR-400' to provide a steady and continuous arc welding, was also conducted to verify the simulated result. By surveying the consistence of molten pool bounded by contrast shade and simulated melting contour on the surface of workpiece, the validity of model proposed to predict the thermal cracker has been successfully identified.

Ho, J.-E. [Department of Mechanical Engineering, National Ilan University, Ilan, Taiwan (China)

2010-05-21T23:59:59.000Z

208

Microstructural issues in a friction-stir-welded aluminum alloy  

SciTech Connect (OSTI)

Recent observations of microstructures associated with friction-stir welding (FSW) in a number of aluminum alloys have consistently demonstrated the actual weld zone to consist of a (dynamically) recrystallized grain structure resulting from the extreme, solid-state, plastic deformation characterizing the process. Because of solubilities associated with the various precipitates in 7075 and 6061 aluminum alloys, and the fact that the precipitates were either homogeneously distributed throughout both the original (unwelded) work-piece plates and the well zones (or formed varying densities of Widmanstaetten patterns within the original and recrystallized grains), it has been difficult to follow the stirring of stable, second-phase particles from the base metal (work-piece) into the weld zone. In the present investigation, a compositionally modified 1100 aluminum alloy (nominally 99.2% Al, 0.5% Fe, 0.15% Cu, 0.12% Si, 0.05 Mn, 0.04 Ti, balance in weight percent of Be and Mg), forming a stable microdendritic (second-phase), equiaxed, cell structure was friction-stir welded. These thermally stable, geometrically specific, precipitates in the base metal were compared with their disposition within the friction-stir-weld zone. In addition, as-cast plates of this alloy were cold-rolled 50% and friction-stir-welded in order to compare these two schedules (as-cast and 50% cold-rolled) in terms of residual hardness variations and related microstructural issues as well as the effect of prior deformation on the friction-stir welding process.

Flores, O.V.; Kennedy, C.; Murr, L.E.; Brown, D.; Pappu, S.; Nowak, B.M.; McClure, J.C. [Univ. of Texas, El Paso, TX (United States)] [Univ. of Texas, El Paso, TX (United States)

1998-02-03T23:59:59.000Z

209

A 2D finite element with through the thickness parabolic temperature distribution for heat transfer simulations including welding  

Science Journals Connector (OSTI)

Abstract The arc welding process involves thermal cycles that cause the appearance of undesirable residual stresses. The determination of this thermal cycle is the first step to a thermomechanical analysis that allows the numerical calculation of residual stresses. This study describes the formulation of a 2D finite element with through the thickness parabolic temperature distribution, including an element estabilization procedure. The 2D element described in this paper can be used to perform thermal analysis more economically than 3D elements, especially in plates, because the number of degrees of freedom through the thickness will always be three. A numerical model of a tungsten arc welding (GTAW) setup was made based on published experimental results. Size and distribution of the heat source input, thermal properties dependent on temperature, surface heat losses by convection and latent heat during phase change were considered. In parallel the same setup was modeled using ANSYS software with 3D elements (SOLID70) to compare against 2D numerical results. The results obtained by 2D model, 3D model and experimental data showed good agreement.

Darlesson Alves do Carmo; Alfredo Rocha de Faria

2015-01-01T23:59:59.000Z

210

Applications and case studies of laser hybrid welding in the automotive industry  

Science Journals Connector (OSTI)

In joining technology, the high welding speed on the one and the good gap bridging ability on the other hand play a significant part. It is no doubt that the laser beam welding and the GMA welding have been established in the welding technology for very long, and that both processes allow a wide field of application in the joining technology. New possibilities and synergetic effects, however, are based on the combination of both processes. The laser radiation causes a very narrow thermally affected zone with a high ratio between welding depth and seam width. In the case of the laser welding process, the gap bridging ability is very low due to the small focus diameter, however very high welding speeds can be achieved. The GMA or Tandem welding process features a significantly lower energy density has a larger focused spot on the material surface and is characterised by its good gap bridging ability.

H. Staufer

2010-01-01T23:59:59.000Z

211

E-Print Network 3.0 - adaptive robotic welding Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

welding Page: << < 1 2 3 4 5 > >> 1 ORIGINAL ARTICLE Development of a mobile welding robot for double-hull structures Summary: , the CPU board recalculates the path of the...

212

Vehicle Technologies Office Merit Review 2014: On-Line Weld NDE...  

Broader source: Energy.gov (indexed) [DOE]

On-Line Weld NDE with IR Thermography Vehicle Technologies Office Merit Review 2014: On-Line Weld NDE with IR Thermography Presentation given by Oak Ridge National Laboratory at...

213

Electron beam welding of ceramic to metal using fore-vacuum plasma electron source  

Science Journals Connector (OSTI)

The possibility of creating ceramic-metal joints by electron beam welding is considered. The welding of ... range (520 Pa) using a plasma electron source. The structure and composition of the ceramic ... breakin...

A. K. Goreev; V. A. Burdovitsin; A. S. Klimov

2012-09-01T23:59:59.000Z

214

Effect of Microstructure on Mechanical Properties of High Strength Steel Weld Metals  

E-Print Network [OSTI]

using for example gas tungsten arc welding (GTAW). However as strength levels increase it becomes more difficult to fulfil impact toughness requirements with flexible and productive welding methods such as shielded metal arc welding (SMAW), flux cored... . Little effects are seen on the cross sectional area of each weld bead deposited with increase in interpass temperature but the proportion of recrystallised area increases [12]. By eliminating the columnar microstructure, hardness becomes more uniform...

Keehan, Enda

2004-01-01T23:59:59.000Z

215

Welding of cast A359/SiC/10p metal matrix composites  

E-Print Network [OSTI]

arc welding GTAW Gas tungsten arc welding HAZ Heat affected zone HF High frequency MMC Metal matrix composite MMCs Metal matrix composites NDE Non-destructive examination SAW Submerged arc welding SMAW Shielded metal arc... limited their applications. Further, the use of composite materials requires us to stay from the established processes and areas of practice that were relevant to more conventional engineering materials. Except for gas tungsten arc welding (GTAW...

Kothari, Mitul Arvind

2005-11-01T23:59:59.000Z

216

Integrated thermal-microstructure model to predict the property gradients in resistance spot steel welds  

SciTech Connect (OSTI)

An integrated model approach was proposed for relating resistance welding parameters to weldment properties. An existing microstructure model was used to determine the microstructural and property gradients in resistance spot welds of plain carbon steel. The effect of these gradients on the weld integrity was evaluated with finite element analysis. Further modifications to this integrated thermal-microstructure model are discussed.

Babu, S.S.; Riemer, B.W.; Santella, M.L. [Oak Ridge National Lab., TN (United States); Feng, Z. [Edison Welding Inst., Columbus, OH (United States)

1998-11-01T23:59:59.000Z

217

Management Plan Management Plan  

E-Print Network [OSTI]

; and 5) consistency with the Endangered Species Act and Clean Water Act. In addition, the management plan Plan, Management Plan Page MP­ 1 #12;Management Plan water quality standards, instream flows, privateManagement Plan Management Plan "Management and restoration programs for native salmonids have

218

Experimental program to assess the effect of residual stresses on fracture behavior  

SciTech Connect (OSTI)

A series of ``model material`` tests were previously undertaken on aluminium alloy tensile loaded plate specimens containing a central through-thickness crack to investigate the effect of in-plane self-balancing residual stresses on ductile tearing behavior in the context of the R6 methodology. Residual stresses were generated by an electron-beam welding method and this resulted in stress levels of the order of 1/3 yield stress in the test specimens. Provisional results of these tests were presented at the 1993 ASME PVP conference. The value of 1/3 yield is commonly considered as the level of residual stress for fracture assessments of structural components which have been stress relieved. For non stress relieved components, higher values of residual stress need to be considered. A new design of test specimen has therefore been developed. Further ductile tearing experiments have been undertaken on this new design of specimen. The results obtained from these, and the previous tests, have quantitatively demonstrated the influence of residual stress on fracture behavior in terms of both the level of residual stress and the region under consideration on the R6 failure assessment diagram. The general conservatism of the current R6 method for dealing with residual stresses has been confirmed for the type of geometry, loading and residual stress field under consideration.

Sharples, J.K.; Sanderson, D.J.; Bowdler, B.R.; Wightman, A.P. [AEA Technology, Risley (United Kingdom). Technical Services Division; Ainsworth, R.A. [Nuclear Electric plc, Berkeley (United Kingdom)

1995-11-01T23:59:59.000Z

219

Dissimilar-weld failure analysis and development program  

SciTech Connect (OSTI)

As a result of the work performed under RP 1874-1, the factors influencing the performance of dissimilar metal welds (DMWs) in elevated temperature power plant boiler service have been defined. Details of the results are given in other volumes of this report series. In this volume, design and procedure guidelines for improving DMW performance are provided. DMW life can be extended by: locating DMWs such that service conditions are conducive to long life; such locations may be identified by the use of the computerized analytical program PODIS, developed under RP 1874; using preferred weld filler metals; and using specific weld configurations. Details of each of these approaches are described herein. 5 figs., 2 tabs.

Roberts, D.I.; Ryder, R.H.; Grunloh, H.J.; Thurgood, B.E. (General Atomics, San Diego, CA (USA))

1989-11-01T23:59:59.000Z

220

Microstructural, mechanical and weldability assessments of the dissimilar welds between ??- and ??-strengthened nickel-base superalloys  

SciTech Connect (OSTI)

Dissimilar welding of ??- and ??-strengthened nickel-base superalloys has been investigated to identify the relationship between the microstructure of the welds and the resultant mechanical and weldability characteristics. ??-Strengthened nickel-base Alloy 500 and ??-strengthened nickel-base Alloy 718 were used for dissimilar welding. Gas tungsten arc welding operations were utilized for performing the autogenous dissimilar welding. Alloy 500 and Alloy 718 base metals showed various types of phases, carbides, intermetallics and eutectics in their microstructure. The results for Alloy 500 weld metal showed severe segregation of titanium to the interdendritic regions. The Alloy 718 weld metal compositional analysis confirmed the substantial role of Nb in the formation of low-melting eutectic-type morphologies which can reduce the weldability. The microstructure of dissimilar weld metal with dilution level of 65% wt.% displayed semi-developed dendritic structure. The less segregation and less formation of low-melting eutectic structures caused to less susceptibility of the dissimilar weld metal to the solidification cracking. This result was confirmed by analytic modeling achievements. Dissolution of ??-Ni{sub 3}Nb precipitations took place in the Alloy 718 heat-affected zone leading to sharp decline of the microhardness in this region. Remelted and resolidified regions were observed in the partially-melted zone of Alloy 500 and Alloy 718. Nevertheless, no solidification and liquation cracking happened in the dissimilar welds. Finally, this was concluded that dissimilar welding of ??- and ??-strengthened nickel-base superalloys can successfully be performed. - Highlights: Dissimilar welding of ??- and ??-strengthened nickel-base superalloys is studied. Microstructural, mechanical and weldability aspects of the welds are assessed. Microstructure of welds, bases and heat-affected zones is characterized in detail. The type, morphology and distribution of the phases are thoroughly investigated. Dissimilar welding is successfully performed without occurrence of any hot cracks.

Naffakh Moosavy, Homam, E-mail: homam_naffakh@iust.ac.ir [School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Tehran 16846-13114 (Iran, Islamic Republic of); Aboutalebi, Mohammad-Reza; Seyedein, Seyed Hossein [School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Tehran 16846-13114 (Iran, Islamic Republic of); Mapelli, Carlo [Dipartimento di Meccanica, Politecnico di Milano, Via La Massa 34, Milan 20156 (Italy)

2013-08-15T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

3612--VOLUME 27A, NOVEMBER 1996 METALLURGICAL AND MATERIALS TRANSACTIONS A Solidification of an Alloy 625 Weld Overlay  

E-Print Network [OSTI]

steel by gas metal arc welding was investigated by light and electron optical microscopy, electron to that produced in dissimilar welds between Alloy 625 and Cr- Mo steels in weld overlay applications of an Alloy 625 Weld Overlay J.N. DuPONT The solidification behavior (microsegregation, secondary phase

DuPont, John N.

222

Simulation of Distortion and Residual Stress Development During Heat Treatment of Steel Castings  

SciTech Connect (OSTI)

Heat treatment and associated processing, such as quenching, are critical during high strength steel casting production. These processes must be managed closely to prevent thermal and residual stresses that may result in distortion, cracking (particularly after machining), re-work, and weld repair. The risk of casting distortion limits aggressive quenching that can be beneficial to the process and yield an improved outcome. As a result of these distortions, adjustments must be made to the casting or pattern design, or tie bars must be added. Straightening castings after heat treatments can be both time-consuming and expensive. Residual stresses may reduce a casting???¢????????s overall service performance, possibly resulting in catastrophic failure. Stress relieving may help, but expends additional energy in the process. Casting software is very limited in predicting distortions during heat treatment, so corrective measures most often involve a tedious trial-and-error procedure. An extensive review of existing heat treatment residual stress and distortion modeling revealed that it is vital to predict the phase transformations and microstructure of the steel along with the thermal stress development during heat treatment. After reviewing the state-of-the-art in heat treatment residual stress and distortion modeling, an existing commercial code was selected because of its advanced capabilities in predicting phase transformations, the evolving microstructure and related properties along with thermal stress development during heat treatment. However, this software was developed for small parts created from forgings or machined stock, and not for steel castings. Therefore, its predictive capabilities for heat treatment of steel castings were investigated. Available experimental steel casting heat treatment data was determined to be of insufficient detail and breadth, and so new heat treatment experiments were designed and performed, casting and heat treating modified versions of the Navy-C ring (a classical test shape for heat treatment experiments) for several carbon and low alloy steels in order to generate data necessary to validate the code. The predicted distortions were in reasonable agreement with the experimentally measured values. However, the final distortions in the castings were small, making it difficult to determine how accurate the predictions truly are. It is recommended that further validation of the software be performed with the aid of additional experiments with large production steel castings that experience significant heat treatment distortions. It is apparent from this research that the mechanical properties of the bonded sand used for cores and sand molds are key in producing accurate stress simulation results. Because of this, experiments were performed to determine the temperature-dependent elastic modulus of a resin-bonded sand commonly utilized in the steel casting industry. The elastic modulus was seen to vary significantly with heating and cooling rates. Also, the retained room temperature elastic modulus after heating was seen to degrade significantly when the sand was heated above 125???????°C. The elastic modulus curves developed in this work can readily be utilized in casting simulation software. Additional experiments with higher heating rates are recommended to determine the behavior of the elastic modulus in the sand close to the mold-metal interface. The commercial heat treatment residual stress and distortion code, once fully validated, is expected to result in an estimated energy savings of 2.15 trillion BTU???¢????????s/year. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology.

Christoph Beckermann; Kent Carlson

2011-07-22T23:59:59.000Z

223

Use of Aria to simulate laser weld pool dynamics for neutron generator production.  

SciTech Connect (OSTI)

This report documents the results for the FY07 ASC Integrated Codes Level 2 Milestone number 2354. The description for this milestone is, 'Demonstrate level set free surface tracking capabilities in ARIA to simulate the dynamics of the formation and time evolution of a weld pool in laser welding applications for neutron generator production'. The specialized boundary conditions and material properties for the laser welding application were implemented and verified by comparison with existing, two-dimensional applications. Analyses of stationary spot welds and traveling line welds were performed and the accuracy of the three-dimensional (3D) level set algorithm is assessed by comparison with 3D moving mesh calculations.

Noble, David R.; Notz, Patrick K.; Martinez, Mario J.; Kraynik, Andrew Michael

2007-09-01T23:59:59.000Z

224

Closed-loop focus control system for laser welding  

SciTech Connect (OSTI)

In this paper the authors describe a focus control system for Nd:YAG laser welding based on an optical sensor incorporated into the fibre delivery system to detect light generated by the process. This broadband light is separated into two wavelength bands, and simple electronic processing gives a signal proportional to focal error, as a result of chromatic aberrations in the optical delivery system. Focus control is demonstrated for bead-on-plate welds in different thicknesses of titanium alloy, aluminum alloy, mild steel and stainless steel. The control system works for both pulsed and continuous laser radiation.

Haran, F.M.; Hand, D.P.; Jones, J.D.C. [Heriot-Watt Univ., Edinburgh (United Kingdom); Peters, C. [Lumonics Ltd., Rugby (United Kingdom)

1996-12-31T23:59:59.000Z

225

Vinyl chloride monomer and other contaminants in PVC welding fumes  

SciTech Connect (OSTI)

An investigation into the nature of fumes produced during thermal welding of plasticized PVC sheeting has been carried out with the objective of determining if the known carcinogen vinyl chloride monomer (VCM) is formed and to assess the level of exposure to the operator. The results show that the atmospheric concentrations of VCM are well below accepted occupational exposure limits. This finding is consistent with reports in the technical literature which suggest that VCM is produced during thermal degradation of PVC only at temperatures considerably higher than those encountered during plastic welding.

Williamson, J.; Kavanagh, B.

1987-05-01T23:59:59.000Z

226

Apparatus and process for ultrasonic seam welding stainless steel foils  

DOE Patents [OSTI]

An ultrasonic seam welding apparatus having a head which is rotated to form contact, preferably rolling contact, between a metallurgically inert coated surface of the head and an outside foil of a plurality of layered foils or work materials. The head is vibrated at an ultrasonic frequency, preferably along a longitudinal axis of the head. The head is constructed to transmit vibration through a contacting surface of the head into each of the layered foils. The contacting surface of the head is preferably coated with aluminum oxide to prevent the head from becoming welded to layered stainless steel foils.

Leigh, Richard W. (New York, NY)

1992-01-01T23:59:59.000Z

227

Fracture behavior of surface cracked wide plates of high strength steel containing overmatched repair welds  

SciTech Connect (OSTI)

This paper presents the experimental results of tests conducted using surface cracked wide plates containing overmatched repair weld joints. The deformation and fracture characteristics of the repair welded wideplates notched at the original weld deposit, repair weld and HAZ regions are discussed. The aim of this work was to investigate the effects of strength mis-match and notch position on the fracture performance of such complex weldments. Furthermore, the predictions of crack driving force using the Engineering Treatment Model for mis-matched welds (ETM-MM) procedure was compared with the results of the wide plates containing semielliptical surface cracks. For this study, 1/2K weld joints were prepared on 30 nm thick pipeline steel X65 plates by using a SAW process, resulting in 50% overmatching. Repair was performed at the cap side of the original joint up to half depth of plate thickness with a GMA welding process under hyperbaric conditions, leading to 41% yield strength overmatching. In order to assess the fracture behavior of these welds, surface cracked (semielliptic defects) wide plates containing original and repair welds were tested in tension at {minus}10 C. The surface cracked wide plate tests results have confirmed that overmatched repair weld metal can exert a significant effect on the deformation and fracture behavior of the wide plates. Wide plates containing root cracks clearly showed a shielding effect of the overmatched repair weld since it prevented development of through thickness ligament yielding.

Junghans, E.; Kocak, M.; Schwalbe, K.H. [GKSS Research Center, Geesthacht (Germany). Inst. of Materials Research

1996-12-01T23:59:59.000Z

228

Gas and RRR distribution in high purity Niobium EB welded in Ultra-High Vacuum  

SciTech Connect (OSTI)

Electron beam (EB) welding in UHV (ultra-high vacuum, 10-5 divide 10-8 mbar) is applied in the standard fabrication of high gradient niobium superconducting radio frequency (SRF) cavities of TESLA design. The quality of EB welding is critical for cavity performance. Experimental data of gas content (H2, O2, N2) and RRR (residual resistivity ratio) measurements in niobium (Nb) welding seams are presented. EB welding in UHV conditions allow to preserve low gas content (1 divide 3 wt. ppm hydrogen and 5 divide 7 ppm oxygen and nitrogen), essential for high values of RRR - 350 divide 400 units. Gas content redistribution in the electron beam welded and heat affected region take place in the welding process. Correlation between gas solubility parameters, RRR and thermal conductivity are presented. Mechanisms of gas solubility in EB welding process are discussed.

Anakhov, S.; Singer, X.; Singer, W.; Wen, H. [RSVPU, Yekaterinburg (Russian Federation); DESY, Hamburg (Germany); IEE CAS, Beijing (China)

2006-05-24T23:59:59.000Z

229

Characterization of Defocused Electron Beams and Welds in Stainless Steel and Refractory Metals using the Enhanced Modified Faraday Cup Diagnostic  

SciTech Connect (OSTI)

As the first part of a project to compare new generation, continuous wave, laser welding technology to traditional electron beam welding technology, electron beam welds were made on commercially pure vanadium refractory metal and 21-6-9 austenitic stainless steel. The electron beam welds were made while employing EB diagnostics to fully characterize the beams so that direct comparisons could be made between electron beam and laser beams and the welds that each process produces.

Elmer, J W

2009-01-23T23:59:59.000Z

230

ASSESSMENT OF RESIDUAL STRESSES IN SRS AND HANFORD 3013 INNER AND CONVENIENCE CANS  

SciTech Connect (OSTI)

Chloride stress corrosion cracking (SCC) is a plausible corrosion mechanism for the stainless steel 3013 containers during their lifetime for plutonium material storage if sufficient electrolyte is present within the container. Contributing factors for SCC, such as fabrication and welding residual stresses, are present in the 3013 cans. Convenience and inner cans from both Hanford and SRS are made by a flow form process, which cold works the stainless steel during fabrication. Additionally, the inner cans also are sealed at the can top with a closure weld to the sealing plug. Only SRS and Hanford were tested since moisture levels were significant for SCC. As part of the 3013 corrosion plan for FY09, testing in a boiling magnesium chloride solution was performed on actual 3013 convenience and inner cans to determine if the residual stresses were sufficient for the initiation and propagation of SCC. Additional testing in a 40% calcium chloride solution was also performed on 304L stainless steel SCC coupons, i.e. stressed teardrop-shaped samples (teardrops), and an inner can welded top to provide comparative results and to assess the effect of residual stresses in a less aggressive environment. The testing performed under this task consisted of 3013 inner and convenience cans and 304L teardrops exposed to a boiling magnesium chloride solutions per ASTM G36 and a 40% calcium chloride solution at 100 C following the guidance of ASTM G123. Cracking occurred in all can types including the inner can bottom and welded top and the bottoms of the SRS and Hanford convenience cans when exposed to the boiling magnesium chloride solution at 155 C. Cracking occurred at different times indicative of the residual stress levels in the cans. 304L teardrops cracked in the shortest time interval and therefore provide a conservative estimate for can performance. Testing in a 40% calcium chloride solution at 100 C demonstrated that cracking occurs in a less aggressive environment but at significantly longer times than in the boiling magnesium chloride. Vapor space cracking was also found to occur in the inner can welded top exposed over the boiling magnesium chloride solution and on 304L teardrops exposed over a hot calcium chloride solution.

Mickalonis, J.

2009-03-01T23:59:59.000Z

231

75th Diamond anniversary American Welding Society annual meeting  

SciTech Connect (OSTI)

Detailed summaries are given for 85 technical sessions papers, 16 brazing and soldering conference papers, 11 education program papers, 15 thermal spray symposium papres, 9 industrial technology sessions papers 2, invited lectures, and 8 posters presented at the 75th annual convention of the American Welding Society. Also included are the names and addresses of all authors, speakers, and presiding officers.

NONE

1994-12-31T23:59:59.000Z

232

Experimental validation of finite element codes for welding deformations  

E-Print Network [OSTI]

Institute for Energy Technology, N-2027 Kjeller, Norway. Abstract A single pass Metal Inert Gas welding. Hamidec , H. G. Fjærd , A. Moa , M. Belletc a SINTEF Materials Technology, N-0314 Oslo, Norway. b University of Oslo, N-0316 Oslo, Norway. c CEMEF Ecole des Mines de Paris, Sophia Antipolis, France. d

Boyer, Edmond

233

.Heat Generation Patterns and Temperature Profiles in_ Electroslag Welding  

E-Print Network [OSTI]

l .Heat Generation Patterns and Temperature Profiles in_ Electroslag Welding ) · T. DEBROY, J process parameters such as the voltage profiles, heat generation patterns and temperature profiles with equivalent slag, electrode and other geometrical variable; Calcu- 0 lations show that the heat generation

Eagar, Thomas W.

234

Pacific Northwest National Laboratory Investigation of the Stress Corrosion Cracking in Nickel-Base Alloys, Volume 2  

SciTech Connect (OSTI)

The objective of this program is to evaluate the primary water stress corrosion cracking (PWSCC) susceptibility of high chromium alloy 690 and its weld metals, establish quantitative measurements of crack-growth rates and determine relationships among cracking susceptibility, environmental conditions and metallurgical characteristics. Stress-corrosion, crack-growth rates have been determined for 12 alloy 690 specimens, 11 alloy 152/52/52M weld metal specimens, 4 alloy 52M/182 overlay specimens and 2 alloy 52M/82 inlay specimens in simulated PWR primary water environments. The alloy 690 test materials included three different heats of extruded control-rod-drive mechanism (CRDM) tubing with variations in the initial material condition and degree of cold work for one heat. Two cold-rolled (CR) alloy 690 plate heats were also obtained and evaluated enabling comparisons to the CR CRDM materials. Weld metal, overlay and inlay specimens were machined from industry mock ups to provide plant-representative materials for testing. Specimens have been tested for one alloy 152 weld, two alloy 52 welds and three alloy 52M welds. The overlay and inlay specimens were prepared to propagate stress-corrosion cracks from the alloy 182 or 82 material into the more resistant alloy 52M. In all cases, crack extension was monitored in situ by direct current potential drop (DCPD) with length resolution of about +1 m making it possible to measure extremely low growth rates approaching 5x10-10 mm/s. Most SCC tests were performed at 325-360C with hydrogen concentrations from 11-29 cc/kg; however, environmental conditions were modified during a few experiments to evaluate the influence of temperature, water chemistry or electrochemical potential on propagation rates. In addition, low-temperature (~50C) cracking behavior was examined for selected alloy 690 and weld metal specimens. Extensive characterizations have been performed on material microstructures and stress-corrosion cracks by optical and electron microscopy techniques and linked to crack-growth test results to help define material and environmental parameters controlling SCC susceptibility.

Bruemmer, Stephen M.; Toloczko, Mychailo B.; Olszta, Matthew J.

2012-03-01T23:59:59.000Z

235

The Stress Corrosion Crack Growth Rate of Alloy 600 Heat Affected Zones Exposed to High Purity Water  

SciTech Connect (OSTI)

Grain boundary chromium carbides improve the resistance of nickel based alloys to primary water stress corrosion cracking (PWSCC). However, in weld heat affected zones (HAZ's), thermal cycles from fusion welding can solutionize beneficial grain boundary carbides, produce locally high residual stresses and strains, and promote PWSCC. The present research investigates the crack growth rate of an A600 HAZ as a function of test temperature. The A600 HAZ was fabricated by building up a gas-tungsten-arc-weld deposit of EN82H filler metal onto a mill-annealed A600 plate. Fracture mechanics based, stress corrosion crack growth rate testing was performed in high purity water between 600 F and 680 F at an initial stress intensity factor of 40 ksi {radical}in and at a constant electrochemical potential. The HAZ samples exhibited significant SCC, entirely within the HAZ at all temperatures tested. While the HAZ samples showed the same temperature dependence for SCC as the base material (HAZ: 29.8 {+-} 11.2{sub 95%} kcal/mol vs A600 Base: 35.3 {+-} 2.58{sub 95%} kcal/mol), the crack growth rates were {approx} 30X faster than the A600 base material tested at the same conditions. The increased crack growth rates of the HAZ is attributed to fewer intergranular chromium rich carbides and to increased plastic strain in the HAZ as compared to the unaffected base material.

George A. Young; Nathan Lewis

2003-04-05T23:59:59.000Z

236

Hospitality Management Hospitality Management  

E-Print Network [OSTI]

of the global hospitality industry. Academic Offerings HOSPITALITY AND FOOD SERVICE MANAGEMENT MINOR HOSPITALITY AND FOOD SERVICE MANAGEMENT MINOR Students pursuing programs in other areas of study may choose a minor Lodging Management 3 HPM 309 Sports Arena Management 3 HPM 312* Cost Control in Food Services (Prereq

McConnell, Terry

237

Microsoft Word - FEAA064O_ORNL_Welding Single Cystal_Factsheet_Rev01.doc  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Welding and Weld Repair of Single Crystal Gas Turbine Alloys Welding and Weld Repair of Single Crystal Gas Turbine Alloys (Oak Ridge National Laboratory) FACT SHEET I. PROJECT PARTICIPANTS A. Prime Participant: Oak Ridge National Laboratory (ORNL) B. Project Partners (no project funds to these partners): General Electric Corporation Siemens-Westinghouse Corporation Electric Power Research Institute (EPRI) PCC Airfoils Honeywell Aerospace Services Pratt and Whitney Corporation South Carolina Institute for Energy Studies II. PROJECT DESCRIPTION A. Objective It is the purpose of this project to investigate the potential for weld refurbishment and repair of single crystal gas turbine engine components and to determine processes, process conditions, and alloy compositions that will make such weld processing possible.

238

Corrosion-fatigue crack growth behavior of surface crack on AH36 TMCP steel weld in seawater  

SciTech Connect (OSTI)

Fatigue crack growth behavior in seawater of surface crack on the weld was studied with a structural steel, AH36, manufactured by the thermo-mechanical control process (TMCP). Crack growth rate was measured for the surface cracks located in different regions of weld, such as the heat affected zone, the weld metal and the base metal. Influence of the welding condition was investigated with the variation of heat inputs of 80, 120 and 180 kJ/cm. Electrochemical analysis of each region of the weld was also performed to investigate the corrosion behavior between the weld and the base metal.

Kweon, Y.G.; Jeong, H.D.; Chang, R.W. [Research Inst. of Industrial Science and Technology, Pohang (Korea, Republic of). Welding Research Center

1995-12-31T23:59:59.000Z

239

Experimental determination of residual stress by neutron diffraction in a boiling water reactor core shroud  

SciTech Connect (OSTI)

Residual strains in a 51 mm (2-inch) thick 304L stainless steel plate have been measured by neutron diffraction and interpreted in terms of residual stress. The plate, measuring (300 mm) in area, was removed from a 6m (20-ft.) diameter unirradiated boiling water reactor core shroud, and included a multiple-pass horizontal weld which joined two of the cylindrical shells which comprise the core shroud. Residual stress mapping was undertaken in the heat affected zone, concentrating on the outside half of the plate thickness. Variations in residual stresses with location appeared consistent with trends expected from finite element calculations, considering that a large fraction of the residual hoop stress was released upon removal of the plate from the core shroud cylinder.

Payzant, A.; Spooner, S.; Zhu, Xiaojing; Hubbard, C.R. [and others

1996-06-01T23:59:59.000Z

240

In-process acoustic emission monitoring of dissimilar metal welding: Final report  

SciTech Connect (OSTI)

A system to provide real-time, in-process acoustic emission monitoring to detect and locate flaws in bimetallic welds has been demonstrated. This system could provide reliable inspection of critical welds in cases where conventional NDE would be costly or impossible to apply. Tests were completed on four sample welds to determine the sensitivity of the system. Artificial flaws were introduced into two test samples and the acoustic emission results were verified by radiography and visual inspection techniques.

Not Available

1989-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Surface preparation effects on GTA weld shape in JBK-75 stainless steel  

SciTech Connect (OSTI)

The results of a study are reported here on the effects of surface preparation on the shape of autogenous gas tungsten arc (GTA) welds in JBK-75, an austenitic precipitation hardenable stainless steel similar to A286. Minor changes in surface preparation produced substantial changes in the fusion zone shape and welding behavior of this alloy. Increased and more consistent depth of fusion (higher d/w ratios) along with improved arc stability and less arc wander resulted from wire brushing and other abrasive surface preparations, although chemical and machining methods did not produce any increase in depth of fusion. Abrasive treatments roughen the surface, increase the surface area, increase the surface oxide thickness, and entrap oxide. The increased weld d/w ratio is attributed to oxygen added to the weld pool from the surface oxide on the base metal. The added oxygen alters the surface-tension-driven fluid flow pattern in the weld pool. Increased depth of fusion in wire-fed U-groove weld joints also resulted when welding wire with a greater surface oxide thickness was used. Increasing the amount of wire brushing produced even deeper welds. However, a maximum in depth of fusion was observed with further wire brushing, beyond which weld fusion depth decreased.

Campbell, R.D.; Robertson, A.M. (AWS Precision Joining Center, Wheat Ridge, CO (United States)); Heiple, C.R. (EG and G Rocky Flats Plant, Golden (Colombia)); Sturgill, P.L.; Jamsay, R.

1993-02-01T23:59:59.000Z

242

E-Print Network 3.0 - advance revolutionary weld Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and Restoration Technologies 3 ORIGINAL ARTICLE Development of a mobile welding robot for double-hull structures Summary: . Bostelman R, Jacoff A, Bunch R (1999) Delivery...

243

Resistance mash welding for joining of copper conductors for electric motors  

Science Journals Connector (OSTI)

Abstract The automotive industry is developing designs and manufacturing processes for a new generation of electric motors intended for use in hybrid and electric vehicles. This paper is focused on using solid-state welding to join rectangular wires in the fabrication of motor stators. Resistance welding has not typically been applied to copper due to its very high electrical conductivity; however through optimization of the current and pressure profiles, excellent quality copper-to-copper joints have been demonstrated with a technique known as resistance mash welding. A better understanding of resistance mash welding characteristics will help advancements in its application for stators. The limitations of this application will be discussed.

John S. Agapiou; Thomas A. Perry

2013-01-01T23:59:59.000Z

244

Effect of strength mismatch on fracture toughness of HSLA steel weld joints  

SciTech Connect (OSTI)

The purpose of this experimental work is to present the results of measured toughness and strength on mismatched weld joints made on HSLA steel grade HT 80. In the determined over and undermatched weld joints the local mismatching in the through thickness direction was found by hardness measurement. It seems that local mismatch because of WM low toughness has controlled the fracture behavior of weld metal and HAZ in both cases instead of the global one. Direct local CTOD({delta}{sub 5}) technique is found to be particular useful for the determination of fracture toughness values on mismatched weld joints.

Rak, I.; Gliha, V.; Gubeljak, N.; Praunseis, Z. [Univ. of Maribor (Slovenia). Faculty of Mechanical Engineering; Kocak, M. [GKSS Research Center, Geesthacht (Germany). Inst. of Material Research

1995-12-31T23:59:59.000Z

245

Resistance Spot Welding of Aluminum Alloy to Steel with Transition Material - From Process to Performance  

SciTech Connect (OSTI)

This paper summarizes work to date on resistance spot welding (RSW) of aluminum alloy to mild steel from process development to performance evaluation. A cold-rolled strip material is introduced as a transition material to aid the resistance welding process. The optimal welding parameters and electrode selections were established using a combination of experimental and analytical approaches. The mechanical behaviors of welded samples was evaluated using static and dynamic strength tests and cyclic fatigue tests. A statistical analysis was also performed to analyze the effect of different failure modes on the sample's peak load and energy absorption.

Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.; Shao, H; Kimchi, Menachem; Menachem Kimchi and Wanda Newman

2004-05-11T23:59:59.000Z

246

UT of bimetallic welds by shear horizontal waves and electromagnetic ultrasonic (EMUS) probes  

SciTech Connect (OSTI)

Bimetallic transition welds include in most cases besides the austenitic weldment an austenitic buttering. Their inspection by ultrasound is strongly complicated by a high degree of elastic anisotropy. The elastic anisotropy results in phase and group velocities of the elastic wave-modes, which are functions of the propagation direction inside the weld metal and which cause skewing of the sound beams. The coarse grain structure leads to enhanced scattering. Furthermore, there exists a mismatch of the acoustical impedances between the weld metal and the base metal, which depends on the angle of incidence at the interface base metal/weld metal and weld metal/buttering. Due to these facts up to now using standard UT-techniques only the HAZ`s are inspected from both sides. In many cases dissimilar metal welds are only accessible from one side. Therefore, US-techniques are necessary which are capable to inspect the whole weld even if there is only access from one side. By improvement of the technology of the EMUS-probes and of the EMUS-instrumentation for the US-transduction of SH-waves a reliable technique for the ISI of dissimilar metal welds and also of austenitic welds is available. The contribution will shortly introduce into the physical basis of the SH-wave technique and present the results of test specimen measurements. The main part of the paper will report about the experiences and the results of field applications in different nuclear power plants.

Huebschen, G.; Salzburger, H.J.; Kroening, M. [Fraunhofer-Inst. fuer Zerstoerungsfreie Pruefverfahren, Saarbruecken (Germany)

1994-12-31T23:59:59.000Z

247

Effect of multiple repairs in girth welds of pipelines on the mechanical properties  

SciTech Connect (OSTI)

This work presents the results of multiple weld repairs in the same area in seamless API X-52 microalloyed steel pipe. Four conditions of shielded metal arc welding repairs and one as-welded specimen of the girth weld were characterized to determine changes in the microstructure, grain size in the heat affected zone, and to evaluate their effect on the mechanical properties of the weld joints. The mechanical properties by means of tension tests, Charpy-V impact resistance and Vickers hardness of the welds were analyzed. The results indicate that significant changes are not generated in the microstructural constituents of the heat affected zone. Grain growth in the heat affected zone at the specimen mid-thickness with the number of repairs was observed. Tensile strength of the weld joints meets the requirement of the API 1104 standard even after the fourth weld repair. Significant reduction in Charpy-V impact resistance with the number of weld repairs was found when the notch location was in the intersection of the fusion line with the specimen mid-thickness. A significant increase in the Vickers hardness of the heat affected zone occurred after the first repair and a gradual decrease in the Vickers hardness occurred as the number of repairs increases.

Vega, O.E.; Hallen, J.M. [Departamento de Ingenieria Metalurgica, ESIQIE-IPN, Laboratorios Pesados de Metalurgia, UPALM, Zacatenco, C.P. 07738, Mexico D.F. (Mexico); Villagomez, A. [Construcciones Maritimas Mexicanas, CMM-PROTEXA, Av. Periferica s/n, Fracc. Lomas de Holche, C.P. 24120, Cd. del Carmen, Campeche (Mexico); Contreras, A. [Instituto Mexicano del Petroleo, Investigacion en Ductos, Corrosion y Materiales, Eje Central Lazaro Cardenas Norte 152 Col. San Bartolo Atepehuacan, C.P. 07730, Mexico D.F. (Mexico)], E-mail: acontrer@imp.mx

2008-10-15T23:59:59.000Z

248

E-Print Network 3.0 - american welding society Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

to Industry Radiography Cameras, Summary: , an inspection company that performs pipeline weld inspections, such as All American Inspections, must... (American Society of...

249

E-Print Network 3.0 - arc welding dynamic Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

a system IO board; arc sensor interface board for weld seam tracking... inverter power source renders possible ... Source: Ang Jr.,, Marcelo H. - Department of Mechanical...

250

Optimising Friction Stir Welding parameters to maximise tensile strength of AA6061 aluminium alloy joints  

Science Journals Connector (OSTI)

AA6061 aluminium alloy (Al-Mg-Si) has widely accepted in the fabrication of light weight structures. Friction Stir Welding (FSW) process is an emerging solid-state joining process which offers several advantages over other fusion welding processes. The welding parameters such as tool rotational speed, welding speed, axial force and tool pin profile play a major role in deciding the joint strength. An attempt has been made to develop a mathematical model to predict tensile strength. Response surface method (RSM) has been used to develop the model and it is optimised using Hooke and Jeeves search technique to attain maximum tensile strength.

K. Elangovan; V. Balasubramanian; S. Babu; M. Balasubramanian

2008-01-01T23:59:59.000Z

251

Weld County, Colorado: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

Weld County, Colorado: Energy Resources Weld County, Colorado: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 40.5265766°, -104.4723301° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":40.5265766,"lon":-104.4723301,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

252

Probabilistic fracture toughness of welded joint for offshore structures  

SciTech Connect (OSTI)

The paper investigated the probabilistic properties for fracture toughness of offshore steel welded joint at 26 C, 0 C, {minus}20 C, {minus}40 C and {minus}60 C by experiment. On the basis of experimental data, it can be proved by statistical method that probabilistic critical CTOD (Crack Tip Opening Displacement) of A131 steel welded joint under different temperatures can be represented approximately by Weibull distribution, and their distribution parameters are also obtained. The P-T-{delta}{sub C} curve is established, which is used to describe the relationship among three parameters: CTOD, temperature and probability. These results are very useful for fracture reliability analysis and defect assessment of offshore structures.

Chen Guoming; Xu Fayan; Fang Huacan [Univ. of Petroleum, Shandong, Dongying (China); Yang Xiaogang [China Offshore Oil Engineering Design Corp., Tianjin (China)

1996-12-01T23:59:59.000Z

253

Development of a nozzle for underwater laser beam welds  

SciTech Connect (OSTI)

The present study describes the work carried out to develop a nozzle for the welding or treatment of surfaces of components underwater. Two different types of nozzles have been investigated: contactless and sealed. With the former a dry working zone could only be achieved at very high gas flow and at a maximum extension of 2--3mm. The nozzles based on the labyrinth sealing concept were capable of producing and maintaining a dry working zone with acceptable gas flow and an extension range of 4mm. In the development of this nozzle the following factors have been considered: number of rubber layers, included angle of the sealing, quantity, position and diameter of the gas outlets and the extension range. The underwater nozzle developed in the course of this work has been successfully tested in a simulated patch welding repair of a stainless steel pipe at 3m water depth.

Habenicht, I.; Santos, J.F. dos; Szelagowski, P. [GKSS Forschungszentrum Geesthacht GmbH (Germany); Franz, T. [Bremen Inst. for Applied Beam Technology (Germany)

1996-12-01T23:59:59.000Z

254

Post weld heat treatment of offshore structures -- A fabricators viewpoint  

SciTech Connect (OSTI)

The operation involving post weld heat treatment (PWHT) of certain components during the fabrication of offshore structures has been a contentious issue since its inception. It has been driven by parent material property requirements, inadequacy of early welding consumables, lack of fundamental performance data and, as a result, over conservative engineering. It inherited procedures generally derived from the pressure vessel industry and until relatively recently did not receive specialized attention. The history of the route by which the current regulations or guidelines have been derived is clearly explained in other dissertations. This paper attempts to explain the ramifications of the current situation as seen by a fabricator. At first sight it may appear a relatively simple exercise which does not create fundamental problems. Unfortunately this is not the situation.

Lochhead, J.C.

1996-12-01T23:59:59.000Z

255

(Quality control and nondestructive test procedures for welded products)  

SciTech Connect (OSTI)

The International Institute of Welding is composed of some 600 technical experts from 36 countries. These individuals are divided by talent and personal interest into fifteen separate groups called Commissions, each with its own charter and goals. The title, and by inference the charter, of Commission V is : Quality Control and Quality Assurance of Welded Products. In pursuit of its charter Commission V has several subcommissions engaged in the development of drafts, procedures, and standards. Those documents subsequently considered suitable may be submitted to the International Organization for Standards (ISO), an organization similar to the American Society for Testing Materials, for acceptance as international standards. All ISO Procedures and standards which have been in effect for five years must undergo review by the initiating body. The results from review of five-year-old standards and procedures and the discussion of other documents proposed for international publication are presented.

Childress, C.E.

1990-11-09T23:59:59.000Z

256

Video Game Device Haptic Interface for Robotic Arc Welding  

SciTech Connect (OSTI)

Recent advances in technology for video games have made a broad array of haptic feedback devices available at low cost. This paper presents a bi-manual haptic system to enable an operator to weld remotely using the a commercially available haptic feedback video game device for the user interface. The system showed good performance in initial tests, demonstrating the utility of low cost input devices for remote haptic operations.

Corrie I. Nichol; Milos Manic

2009-05-01T23:59:59.000Z

257

Modeling of the Thermal Field in Dissimilar Alloy Ultrasonic Welding  

E-Print Network [OSTI]

, which may, therefore, be assumed to be constant and stationary. The energy delivered to the sample depends on the machine settings for power input and impedance. The latter was optimized for every material combination, in order to maximize energy... Effect, 16 Interna- tional Conference on Structural Mechanics in Reactor Technology, (Washington, DC), 2001 6. S. Bozzi, A.L. Helbert-Etter, T. Baudin, B. Criqui, and J.G. Kerbiguet, Intermetallic Compounds in Al 6016/IF-Steel Friction Stir Spot Welds...

Jedrasiak, P.; Shercliff, H. R.; Chen, Y. C.; Wang, L.; Prangnell, P.; Robson, J.

2014-12-10T23:59:59.000Z

258

Welding/sealing glass-enclosed space in a vacuum  

DOE Patents [OSTI]

A method of welding and sealing the edges of two juxtaposed glass sheets together to seal a vacuum space between the sheets comprises the steps of positioning a radiation absorbant material, such as FeO, VO.sub.2, or NiO, between the radiation transmissive glass sheets adjacent the edges and then irradiating the absorbant material, preferably with a laser beam, through at least one of the glass sheets. Heat produced by the absorbed radiation in the absorbant material melts glass in the portions of both glass sheets that are adjacent the absorbant material, and the melted glass from both sheets flows together to create the weld when the melted glass cools and hardens. The absorbant material can be dissolved and diffused into the melted glass to the extent that it no longer absorbs enough energy to keep the glass melted, thus, with appropriate proportioning of absorbant material to source energy power and welding heat needed, the process can be made self-stopping.

Tracy, C. Edwin (Golden, CO); Benson, David K. (Golden, CO)

1996-01-01T23:59:59.000Z

259

Steam generator conceptual design for the modular HTGR - Dissimilar metal weld considerations  

SciTech Connect (OSTI)

The steam generator for the current Modular High Temperature Gas-Cooled Reactor (MHTGR) has evolved from a technology basis developed in U.S. and European gas-cooled reactor programs. The MHTGR steam generator is a vertically-oriented, counterflow, shell-and-tube, once-through, non-reheat, helical heat exchanger with helium on the shell side and water/steam in the tubes. In the MHTGR applications, the normal operating temperatures of the steam generator tubes can be as high as 638/sup 0/C (1180/sup 0/F). Concerns such as cost, creep strength, steam side scaling and stress corrosion cracking often lead to a design decision to use two different tube materials, one for the evaporating portion and another for the superheating portion of the steam generator. The current MHTGR steam generator design utilizes 2 1/4 CR - 1 Mo material for the economizer/evaporator/initial superheater tube section and Alloy 800H material for the finishing superheat tube section. Therefore, a dissimilar metal weld (DMW) is incorporated in each tube circuit. This feature of the design imposes certain important constraints on the steam generator designer. This paper presents an overview of the MHTGR steam generator conceptual design, and then focuses on the DMW considerations and how these have influenced the design configuration.

Spring, A.H.; Basol, M.

1987-01-01T23:59:59.000Z

260

Capabilities of Ultrasonic Techniques for the Far-Side Examination of Austenitic Stainless Steel Piping Welds.  

SciTech Connect (OSTI)

A study was conducted to assess the ability of advanced ultrasonic techniques to detect and accurately determine the size of flaws from the far-side of wrought austenitic piping welds. Far-side inspections of nuclear system piping welds are currently performed on a best effort basis and do not conform to ASME Code Section XI Appendix VIII performance demonstration requirements. For this study, four circumferential welds in 610mm diameter, 36mm thick ASTM A-358, Grade 304 vintage austenitic stainless steel pipe were examined. The welds were fabricated with varied welding parameters; both horizontal and vertical pipe orientations were used, with air and water backing, to simulate field welding conditions. A series of saw cuts, electro-discharge machined (EDM) notches, and implanted fatigue cracks were placed into the heat affected zones of the welds. The saw cuts and notches ranged in depth from 7.5% to 28.4% through-wall. The implanted cracks ranged in depth from 5% through-wall to 64% through-wall. The welds were examined with phased array technology at 2.0 MHz, and with low-frequency/Synthetic Aperture Focusing Technique (SAFT) methods in the 250-400 kHz regime. These results were compared to conventional ultrasonic techniques as a baseline. The examinations showed that both phased-array and low-frequency/SAFT were able to detect and accurately length-size, but not depth size, the notches and flaws through the welds. The ultrasonic results were insensitive to the different welding techniques used in each weld.

Anderson, Michael T.; Diaz, Aaron A.; Cumblidge, Stephen E.; Doctor, Steven R.

2006-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Refractory metal welding using a 3.3 kW diode pumped Nd:YAG laser.  

SciTech Connect (OSTI)

Recent developments in multi-kilowatt continuous wave lasers allow fiber optic delivery to high-purity controlled atmosphere chambers and challenge electron beam welding with improvements in cost, complexity, beam quality and flexibility. Questions remain with respect to the performance of these lasers for refractory alloy welding regarding damaging back reflections, laser-plume interactions, and sufficiency of beam intensity and coupled energy. System performance for the welding of various refractory metal alloys and comparisons to electron beam welds will be presented.

Carpenter, R. W. (Robert W.); Piltch, M. S. (Martin S.); Nemec, R. B. (Ronald B.); Milewski, J. O. (John O.)

2001-01-01T23:59:59.000Z

262

The influence of position in overlap joints of Mg and Al alloys on microstructure and hardness of laser welds.  

E-Print Network [OSTI]

assembly. Therefore, the dissimilar-metal welding process has been identified as top priority for materials and resistance of this combination, and lead to the formation of intermetallic compounds in the welded metal. Keywords: laser welding, dissimilar materials, AZ31 magnesium alloy, A5754 aluminum alloy, microstructure

Paris-Sud XI, Université de

263

MECHANICAL PROPERTIES AND MICROSTRUCTURAL CHARACTERIZATION OF A MULTILAYERED MULTIPASS FRICTION STIR WELD IN STEEL  

SciTech Connect (OSTI)

Multilayered multipass friction stir welding (MM-FSW) makes it possible to use FSW to fabricate thick-section structures. In this work, MM-FSW was demonstrated on a high strength low alloy steel; ASTM A572 Grade 50. Three steel plates with thicknesses of 0.18", 0.18", 0.24" respectively were stacked and friction stir welded together to form a 0.6" thick welded structure. The welded plate was sectioned into rectangular bars transverse to the weld direction for tensile testing to evaluate mechanical properties. Digital image correlation (DIC) was employed to map the local strain fields during tensile testing. The initial failure was found to occur simultaneously at the bottom and middle layers away from the weld zone. The top layer failed last in the base metal. The failure locations were consistent among different samples tested. Also, Charpy V-notch impact tests were conducted for weld metal, heat affected zone, and the base metal at each layer as a function of temperature. The weld microstructures were characterized using optical and electron microscopy and micro-hardness mapping.

Lim, Yong Chae [ORNL; Sanderson, Samuel [MegaStir Technologies LLC; Mahoney, Murray [Consultant; Qiao, Dongxiao [ORNL; Wang, Yanli [ORNL; Zhang, Wei [ORNL; Feng, Zhili [ORNL

2013-01-01T23:59:59.000Z

264

Integration of Laser-Welded Ag Nanowire Transparent Conducting Layers on Photovoltaic Devices (DMR-0819860)  

E-Print Network [OSTI]

Integration of Laser-Welded Ag Nanowire Transparent Conducting Layers on Photovoltaic Devices (DMR conducting layers in applications ranging from organic flexible electronics to rigid photovoltaics. However of a hybrid organic photovoltaic device [1]. The NWs are dispersed on the device and the network is welded

Petta, Jason

265

Convection in Arc Weld Pools Electromagnetic and surface tension forces are shown to  

E-Print Network [OSTI]

Convection in Arc Weld Pools Electromagnetic and surface tension forces are shown to dominate flow tension forces. It is shown that the electromag- netic and surface tension forces domi- nate the flow by experimental measurements of segrega- tion in the weld pool. It is also shown that the surface tension driven

Eagar, Thomas W.

266

Hydrogen-induced cracking along the fusion boundary of dissimilar metal welds  

SciTech Connect (OSTI)

Presented here are the results from a series of experiments in which dissimilar metals welds were made using the gas tungsten arc welding process with pure argon or argon-6% hydrogen shielding gas. The objective was to determine if cracking near the fusion boundary of dissimilar metal welds could be caused by hydrogen absorbed during welding and to characterize the microstructures in which cracking occurred. Welds consisted of ER308 and ER309LSi austenitic stainless steel and ERNiCr-3-nickel-based filler metals deposited on A36 steel base metal. Cracking was observed in welds made with all three filler metals. A ferrofluid color metallography technique revealed that cracking was confined to regions in the weld metal containing martensite. Microhardness indentations indicated that martensitic regions in which cracking occurred had hardness values from 400 to 550 HV. Cracks did not extend into bulk weld metal with hardness less than 350 HV. Martensite formed near the fusion boundary in all three filler metals due to regions of locally increased base metal dilution.

Rowe, M.D.; Nelson, T.W.; Lippold, J.C. [Ohio State Univ., Columbus, OH (United States)

1999-02-01T23:59:59.000Z

267

CO{sub 2} laser beam welding of magnesium-based alloys  

SciTech Connect (OSTI)

Magnesium has gained increased attention in recent years as a structural metal--especially in the automotive industry--necessitating the development of welding techniques qualified for this new application. Lasers are known to be an excellent tool for joining metals. This paper presents results of recent investigations on the weldability of several cast and wrought magnesium-based alloys. Plates with a thickness of 2.5--8 mm were butt joint welded with and without filler metal using a 2.5-kW CO{sub 2} laser. The investigations showed that magnesium alloys can be easily laser welded in similar and dissimilar joints. The beam characteristics of the laser leads to small welds and a deep penetration depth. Crackfree welds exhibiting low porosity and good surface finish can be achieved with appropriate process parameters. Generally, the laser welding leads to either no change or a small increase in hardness in the fusion zone (FZ) and in the heat-affected zone (HAZ) relative to the base metal. Less promising results were obtained for the cast alloy QE22, in which cracking in the age-hardened condition and a significant decrease in hardness occurred. Laser welded die cast alloys showed an extremely high level of porosity in the weld.

Weisheit, A.; Galun, R.; Mordike, B.L. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Werkstoffkunde und Werkstofftechnik

1998-04-01T23:59:59.000Z

268

ORIGINAL ARTICLE Strength and microstructure of laser fusion-welded TiSS  

E-Print Network [OSTI]

ORIGINAL ARTICLE Strength and microstructure of laser fusion-welded Ti­SS dissimilar material pair robust and reliable dissimilar metal joints has the potential to enable new func- tionalities and reduce the manufacturing costs of medical devices. The need for dissimilar material welds in the med- ical device industry

Yao, Y. Lawrence

269

Joint strength in high speed friction stir spot welded DP 980 steel  

SciTech Connect (OSTI)

High speed friction stir spot welding was applied to 1.2 mm thick DP 980 steel sheets under different welding conditions, using PCBN tools. The range of vertical feed rates used during welding was 2.5 mm 102 mm per minute, while the range of spindle speeds was 2500 6000 rpm. Extended testing was carried out for five different sets of welding conditions, until tool failure. These welding conditions resulted in vertical welding loads of 3.6 8.2 kN and lap shear tension failure loads of 8.9 11.1 kN. PCBN tools were shown, in the best case, to provide lap shear tension fracture loads at or above 9 kN for 900 spot welds, after which tool failure caused a rapid drop in joint strength. Joint strength was shown to be strongly correlated to bond area, which was measured from weld cross sections. Failure modes of the tested joints were a function of bond area and softening that occurred in the heat-affected zone.

Saunders, Nathan; Miles, Michael; Hartman, Trent; Hovanski, Yuri; Hong, Sung Tae; Steel, Russell

2014-05-01T23:59:59.000Z

270

Reliability of Laser Welding Process for ZE41A-T5 Magnesium Alloy Sand Castings  

E-Print Network [OSTI]

Reliability of Laser Welding Process for ZE41A-T5 Magnesium Alloy Sand Castings Haider Al-Kazzaz1 for magnesium alloys. The process reliability of 2-mm ZE41A-T5 butt joints welded by a 4 kW Nd:YAG laser, reproducibility, Weibull distribution 1. Introduction The applications of magnesium alloys are expanding rapidly

Medraj, Mamoun

271

Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D  

E-Print Network [OSTI]

Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D W. Zhou*, T. Z. Long and C. K ductility, and the HAZ was found to be the `weakest link'. Keywords: Magnesium alloy, AZ91D, TIG welding, Hot cracking, Liquation, Fracture Introduction Magnesium alloys have high strength/weight ratio

Zhou, Wei

272

Computational Analysis of Material Flow During Friction Stir Welding of AA5059 Aluminum Alloys  

E-Print Network [OSTI]

Computational Analysis of Material Flow During Friction Stir Welding of AA5059 Aluminum Alloys M, solid-solution strengthened and strain-hardened aluminum alloy) is represented using a modified version using FSW, the industrial interest has been primary in the welding of aluminum alloys. For a wide

Grujicic, Mica

273

Special Nuclear Materials: EM Manages Plutonium, Highly Enriched Uranium  

Broader source: Energy.gov (indexed) [DOE]

Nuclear Materials & Waste » Nuclear Materials & Waste » Special Nuclear Materials: EM Manages Plutonium, Highly Enriched Uranium and Uranium-233 Special Nuclear Materials: EM Manages Plutonium, Highly Enriched Uranium and Uranium-233 105-K building houses the K-Area Material Storage (KAMS) facility, designated for the consolidated storage of surplus plutonium at Savannah River Site pending disposition. The plutonium shipped to KAMS is sealed inside a welded 3013 containers that are nested in 9975 shipping containers. 105-K building houses the K-Area Material Storage (KAMS) facility, designated for the consolidated storage of surplus plutonium at Savannah River Site pending disposition. The plutonium shipped to KAMS is sealed inside a welded 3013 containers that are nested in 9975 shipping

274

Apparent Welding Textures In Altered Pumice-Rich Rocks | Open Energy  

Open Energy Info (EERE)

Apparent Welding Textures In Altered Pumice-Rich Rocks Apparent Welding Textures In Altered Pumice-Rich Rocks Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Apparent Welding Textures In Altered Pumice-Rich Rocks Details Activities (0) Areas (0) Regions (0) Abstract: Fiamme and eutaxitic texture are common in ancient non-welded, pumice breccias. The fiamme are phyllosilicate-rich lenses that define a bedding-parallel foliation resembling eutaxitic texture in welded ignimbrites. Pumice breccias in the Cambrian Mount Read Volcanics (Australia) are composed of tube pumice clasts, bubble-wall shards, plagioclase crystal fragments and volcanic lithic clasts, and contain dark green fiamme and stylolites. These sericite or chlorite+sericite fiamme are aligned roughly parallel to regional bedding, and are enclosed in pale pink

275

Characterization of Service Induced Flaws on the Far Side of Austenitic Welds Using Phased Array Technology  

SciTech Connect (OSTI)

Conventional ultrasonic testing methods continue to exhibit problems for applications involving coarse-grained structures. Pacific Northwest National Laboratory is evaluating the capabilities and limitations of phased array (PA) technology to detect service-type flaws in these coarse-grained materials. The work is being sponsored by the U.S. Nuclear Regulatory Commission, Office of Research. Work to determine detection capabilities through welds with varied grain structures is being explored to provide a better understanding of the acoustic properties of these welded structures. Piping specimens with welds fabricated in vertical and horizontal positions to simulate field conditions have been studied. The insights gained from the austenitic piping will be applied to dissimilar metal weld configurations, corrosion resistant clad piping and cast stainless steels. This paper presents results for using PA ultrasonic technology to determine the effectiveness of detecting and accurately characterizing flaws on the far-side of austenitic piping welds.

Anderson, Michael T.; Cumblidge, Stephen E.

2004-01-01T23:59:59.000Z

276

Influence of Alloy and Solidification Parameters on Grain Refinement in Aluminum Weld Metal due to Inoculation  

SciTech Connect (OSTI)

The goals are: (1) Establish how much Ti/B grain refiner is need to completely refine aluminum weld metal for different alloys and different welding conditions; (2) Characterize how alloy composition and solidification parameters affect weld metal grain refinement; and (3) Apply relevant theory to understand observed behavior. Conclusions are: (1) additions of Ti/B grain refiner to weld metal in Alloys 1050, 5083, and 6082 resulted in significant grain refinement; (2) grain refinement was more effective in GTAW than LBW, resulting in finer grains at lower Ti content - reason is limited time available for equiaxed grain growth in LBW (inability to occlude columnar grain growth); (3) welding travel speed did not markedly affect grain size within GTAW and LBW clusters; and (4) application of Hunt CET analysis showed experimental G to be on the order of the critical G{sub CET}; G{sub CET} was consistently higher for GTAW than for LBW.

Schempp, Philipp [BAM, Germany; Tang, Z. [BIAS, Germany; Cross, Carl E. [Los Alamos National Laboratory; Seefeld, T. [BIAS, Germany; Pittner, A. [BAM, Germany; Rethmeier, M. [BAM, Germany

2012-06-28T23:59:59.000Z

277

The influence of laser welding parameters on the microstructure and mechanical property of the as-jointed NiTi alloy wires  

E-Print Network [OSTI]

The influence of laser welding parameters on the microstructure and mechanical property of the as September 2007; accepted 27 November 2007 Available online 4 December 2007 Abstract The Nd:YAG laser welding width and welding current. The aim was to assess the influence of the laser-welding process

Zheng, Yufeng

278

Thin plate gap bridging study for Nd:YAG pulsed laser lap welds.  

SciTech Connect (OSTI)

In an on going study of gap bridging for thin plate Nd:YAG laser lap welds, empirical data, high speed imaging, and computer modeling were utilized to better understand surface physics attributed to the formation and solidification of a weld pool. Experimental data indicates better gap bridging can be achieved through optimized laser parameters such as pulse length, duration, and energy. Long pulse durations at low energies generating low peak powers were found to create the highest percent of gap bridging ability. At constant peak power, gap-bridging ability was further improved by using a smaller spot diameter resulting in higher irradiances. Hence, welding in focus is preferable for bridging gaps. Gas shielding was also found to greatly impact gap-bridging ability. Gapped lap welds that could not be bridged with UHP Argon gas shielding, were easily bridged when left unshielded and exposed to only air. Incident weld angle and joint offset were also investigated for their ability to improve gap bridging. Optical filters and brightlight surface illumination enabled high-speed imaging to capture the fluid dynamics of a forming and solidifying weld pool. The effects of various laser parameters and the weld pool's interaction with the laser beam could also be observed utilizing the high-speed imaging. The work described is used to develop and validate a computer model with improved weld pool physics. Finite element models have been used to derive insight into the physics of gap bridging. The dynamics of the fluid motion within the weld pool in conjunction with the free surface physics have been the primary focus of the modeling efforts. Surface tension has been found to be a more significant factor in determining final weld pool shape than expected.

Roach, Robert Allen; Fuerschbach, Phillip William; Bernal, John E.; Norris, Jerome T.

2006-01-01T23:59:59.000Z

279

Diffusion-Welded Microchannel Heat Exchanger for Industrial Processes  

SciTech Connect (OSTI)

The goal of next generation reactors is to increase energy ef?ciency in the production of electricity and provide high-temperature heat for industrial processes. The ef?cient transfer of energy for industrial applications depends on the ability to incorporate effective heat exchangers between the nuclear heat transport system and the industrial process. The need for ef?ciency, compactness, and safety challenge the boundaries of existing heat exchanger technology. Various studies have been performed in attempts to update the secondary heat exchanger that is downstream of the primary heat exchanger, mostly because its performance is strongly tied to the ability to employ more ef?cient industrial processes. Modern compact heat exchangers can provide high compactness, a measure of the ratio of surface area-to-volume of a heat exchange. The microchannel heat exchanger studied here is a plate-type, robust heat exchanger that combines compactness, low pressure drop, high effectiveness, and the ability to operate with a very large pressure differential between hot and cold sides. The plates are etched and thereafter joined by diffusion welding, resulting in extremely strong all-metal heat exchanger cores. After bonding, any number of core blocks can be welded together to provide the required ?ow capacity. This study explores the microchannel heat exchanger and draws conclusions about diffusion welding/bonding for joining heat exchanger plates, with both experimental and computational modeling, along with existing challenges and gaps. Also, presented is a thermal design method for determining overall design speci?cations for a microchannel printed circuit heat exchanger for both supercritical (24 MPa) and subcritical (17 MPa) Rankine power cycles.

Piyush Sabharwall; Denis E. Clark; Michael V. Glazoff; Michael G. McKellar; Ronald E. Mizia

2013-03-01T23:59:59.000Z

280

G-tunnel welded tuff mining experiment preparations  

SciTech Connect (OSTI)

Designers and analysts of radioactive waste repositories must be able to predict the mechanical behavior of the host rock. Sandia National Laboratories elected to conduct a mine-by in welded tuff so that predictive-type information could be obtained regarding the response of the rock to a drill and blast excavation process, where smooth blasting techniques were used. Included in the study were evaluations of and recommendations for various measurement systems that might be used in future mine-by efforts. This report summarizes the preparations leading to the recording of data. 17 refs., 27 figs., 5 tabs.

Zimmerman, R.M. [Sandia National Labs., Albuquerque, NM (USA); Bellman, R.A. Jr.; Mann, K.L. [Science Applications International Corp., Las Vegas, NV (USA); Zerga, D.P. [Parsons, Brinckerhoff, Quade and Douglas, Inc., San Francisco, CA (USA)

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Additive manufacturing with friction welding and friction deposition processes  

Science Journals Connector (OSTI)

Most of the commercially available additive manufacturing processes that are meant for fabrication of fully dense metallic parts involve melting and solidification. Consequently, these processes suffer from a variety of metallurgical problems. Processes that can facilitate material addition in solid-state are therefore ideally suited for additive manufacturing. In this work, we explore two new solid-state processes, viz. friction welding and friction deposition, for additive manufacturing. Stainless steel samples produced using these processes showed excellent layer bonding and Z-direction tensile properties. The authors believe that these processes are uniquely capable and can offer significant benefits over existing commercial additive manufacturing processes.

J.J.S. Dilip; G.D. Janaki Ram; B.E. Stucker

2012-01-01T23:59:59.000Z

282

Fabrication Flaws in Reactor Pressure Vessel Repair Welds  

SciTech Connect (OSTI)

This paper describes the fabrication flaw distribution and characterization in the repair weld metal of reactor pressure vessels. This work indicates that the large flaws occur in these repairs. These results show that repair flaws are complex in composition and sometimes include cracks on the repair ends. Parametric analysis using an exponential fit is performed on the data. A description of repair flaw morphology is provided. Fabrication flaws in repairs are characterized using high sensitivity nondestructive ultrasonic testing, validation by other nondestructive evaluation (NDE) techniques, and complemented by destructive testing.

Schuster, George J.; Doctor, Steven R.

2007-12-01T23:59:59.000Z

283

Technical Letter Report Assessment of Ultrasonic Phased Array Inspection Method for Welds in Cast Austenitic Stainless Steel Pressurizer Surge Line Piping JCN N6398, Task 1B  

SciTech Connect (OSTI)

Research is being conducted for the U.S. Nuclear Regulatory Commission (NRC) at the Pacific Northwest National Laboratory (PNNL) to assess the effectiveness and reliability of advanced nondestructive examination (NDE) methods for the inspection of light water reactor components. The scope of this research encompasses primary system pressure boundary materials including cast austenitic stainless steels (CASS); dissimilar metal welds; piping with corrosion-resistant cladding; weld overlays, inlays and onlays; and far-side examinations of austenitic piping welds. A primary objective of this work is to evaluate various NDE methods to assess their ability to detect, localize, and size cracks in coarse-grained steel components. In this effort, PNNL supports cooperation with Commissariat lEnergie Atomique (CEA) to assess reliable inspection of CASS materials. The NRC Project Manager has established a cooperative effort with the Institut de Radioprotection et de Surete Nucleaire (IRSN). CEA, under funding from IRSN, are supporting collaborative efforts with the NRC and PNNL. Regarding its work on the NDE of materials, CEA is providing its modeling software (CIVA) in exchange for PNNL offering expertise and data related to phased-array detection and sizing, acoustic attenuation, and back scattering on CASS materials. This collaboration benefits the NRC because CEA performs research and development on CASS for lectricit de France (EdF). This technical letter report provides a summary of a technical evaluation aimed at assessing the capabilities of phased-array (PA) ultrasonic testing (UT) methods as applied to the inspection of welds in CASS pressurizer (PZR) surge line nuclear reactor piping. A set of thermal fatigue cracks (TFCs) was implanted into three CASS PZR surge-line specimens (pipe-to-elbow welds) that were fabricated using vintage CASS materials formed in the 1970s, and flaw responses from these cracks were used to evaluate detection and sizing performance of the PA-UT methods applied. This effort was comprised of multiple elements that included use of microstructural knowledge (dimensional analysis, grain orientation, and grain type) as well as sound field modeling to more effectively modify inspection parameters and enhance the inspection outcomes. Advanced probe design and sound field simulations were employed to enhance detection and characterization of circumferentially oriented flaws, and an assessment of lateral (circumferential) flaw localization capability and performance was also conducted. An evaluation of flaw detection, length sizing, depth sizing, and signal-to-noise ratio was performed for all flaws in the subject specimens, as a function of various inspection parameters, and finally, measurements were made to quantify and assess the baseline CASS material noise and its potential impact on flaw detection.

Diaz, Aaron A.; Cinson, Anthony D.; Crawford, Susan L.; Mathews, Royce; Moran, Traci L.; Anderson, Michael T.

2009-07-28T23:59:59.000Z

284

Surface preparation effects on GTA (gas tungsten arc) weld penetration in JBK-75 stainless steel  

SciTech Connect (OSTI)

The results of a study are reported here on the effects of surface preparation on the shape of GTA welds on JBK-75, an austenitic precipitation hardenable stainless steel similar to A286. Minor changes in surface (weld groove) preparation produced substantial changes in the penetration characteristics and welding behavior of this alloy. Increased and more consistent weld penetration (higher d/w ratios) along with improved arc stability and less arc wander result from wire brushing and other abrasive surface preparations, although chemical and machining methods did not produce any improvement in penetration. Abrasive treatments roughen the surface, increase the surface area, and increase the surface oxide thickness. The increased weld d/w ratio is attributed to oxygen added to the weld pool from the surface oxide on the base metal. The added oxygen alters the surface-tension driven fluid flow pattern in the weld pool. Similar results were observed with changes in filler wire surface oxide thickness, caused by changes in wire production conditions. 15 refs., 14 figs., 4 tabs.

Campbell, R.D.; Heiple, C.R.; Sturgill, P.L.; Robertson, A.M.; Jamsay, R.

1989-01-01T23:59:59.000Z

285

The problems of weld metal or heat affected zone toughness in offshore structural steels  

SciTech Connect (OSTI)

An extensive set of fracture toughness results for welded offshore structural steels, gathered from nine separate sponsoring companies, has been entered into a specially constructed database. With over eleven thousand Charpy results and over two thousand CTOD results available, it has been possible to analyze the occurrence of low toughness results with respect to variables such as thickness, PWHT, steel production route etc., even though the individual test programs were not specifically structured to do this. This paper concentrates on the toughness of the weld metal. The data demonstrates that the likelihood of a low toughness result from a CTOD test in weld metal at {minus}10 C is comparable with that from the HAZ region for welded offshore structural steels, and PWHT of the joint is beneficial in reducing the occurrence of low toughness values in the weld metal. It is therefore important that when the HAZ performance is assessed, either through weld procedure tests or plate prequalification procedures, adequate attention is also paid to the weld metal toughness.

Hancock, P.; Spurrier, J.; Chubb, J.P. [Cranfield Univ. (United Kingdom). School of Industrial and Manufacturing Science

1996-12-01T23:59:59.000Z

286

Nondestructive, in-process inspection of inertia friction welding : an investigation into a new sensing technique.  

SciTech Connect (OSTI)

This paper investigates the capabilities of a new sensor for in-process monitoring of quality during friction welding. The non-contact sensor is composed of microphones that are mounted in an aluminum ring which surrounds the weld joint. The sensor collects the acoustical energy (in the form of sound pressure) that is emitted during the plastic deformation and phase transformations (if applicable) in friction welding processes. The focus in this preliminary investigation is to search for and identify features within the acoustical emission that are indicative of bond quality. Bar-to-bar inertia friction welding (one form of friction welding) of copper to 304L stainless steel is used in this proof-of-concept study. This material combination exhibits only marginal weldability and is ideally suited for validating the capabilities of this new sensing technique. A probabilistic neural network is employed in this work to analyze the acoustical emission's frequency spectrum in an attempt to classify acceptable, conditional, and unacceptable welds. Our preliminary findings indicate that quality-based process features do exist within the frequency spectrum of the acoustical signature. The results from this analysis are presented. Future work in improving the sensing and interpretation of the data is discussed in an effort to develop a robust method of quality-based, in-process monitoring of friction welds.

Hartman, D. A. (Daniel A.); Cola, M. J. (Mark J.); Dave, V. R. (Vivek R.); Dozhier, N. G. (Nathan G.); Carpenter, R. W. (Robert W.)

2002-01-01T23:59:59.000Z

287

Microstructure/property relationships in dissimilar welds between duplex stainless steels and carbon steels  

SciTech Connect (OSTI)

The metallurgical characteristics, toughness and corrosion resistance of dissimilar welds between duplex stainless steel Alloy 2205 and carbon steel A36 have been evaluated. Both duplex stainless steel ER2209 and Ni-based Alloy 625 filler metals were used to join this combination using a multipass, gas tungsten arc welding (GTAW) process. Defect-free welds were made with each filler metal. The toughness of both the 625 and 2209 deposits were acceptable, regardless of heat input. A narrow martensitic region with high hardness was observed along the A36/2209 fusion boundary. A similar region was not observed in welds made with the 625 filler metal. The corrosion resistance of the welds made with 2209 filler metal improved with increasing heat input, probably due to higher levels of austenite and reduced chromium nitride precipitation. Welds made with 625 exhibited severe attack in the root pass, while the bulk of the weld was resistant. This investigation has shown that both filler metals can be used to joint carbon steel to duplex stainless steels, but that special precautions may be necessary in corrosive environments.

Barnhouse, E.J. [Weirton Steel Corp., WV (United States); Lippold, J.C. [Ohio State Univ., Columbus, OH (United States)

1998-12-01T23:59:59.000Z

288

Friction Stir Spot Welding (FSSW) of Advanced High Strength Steel (AHSS)  

SciTech Connect (OSTI)

Friction stir spot welding (FSSW) is applied to join advanced high strength steels (AHSS): galvannealed dual phase 780 MPa steel (DP780GA), transformation induced plasticity 780 MPa steel (TRIP780), and hot-stamped boron steel (HSBS). A low-cost Si3N4 ceramic tool was developed and used for making welds in this study instead of polycrystalline cubic boron nitride (PCBN) material used in earlier studies. FSSW has the advantages of solid-state, low-temperature process, and the ability of joining dissimilar grade of steels and thicknesses. Two different tool shoulder geometries, concave with smooth surface and convex with spiral pattern, were used in the study. Welds were made by a 2-step displacement control process with weld time of 4, 6, and 10 seconds. Static tensile lap-shear strength achieved 16.4 kN for DP780GA-HSBS and 13.2kN for TRIP780-HSBS, above the spot weld strength requirements by AWS. Nugget pull-out was the failure mode of the joint. The joining mechanism was illustrated from the cross-section micrographs. Microhardness measurement showed hardening in the upper sheet steel (DP780GA or TRIP780) in the weld, but softening of HSBS in the heat-affect zone (HAZ). The study demonstrated the feasibility of making high-strength AHSS spot welds with low-cost tools.

Santella, M. L.; Hovanski, Yuri; Pan, Tsung-Yu

2012-04-16T23:59:59.000Z

289

Multiple pass and multiple layer friction stir welding and material enhancement processes  

DOE Patents [OSTI]

Processes for friction stir welding, typically for comparatively thick plate materials using multiple passes and multiple layers of a friction stir welding tool. In some embodiments a first portion of a fabrication preform and a second portion of the fabrication preform are placed adjacent to each other to form a joint, and there may be a groove adjacent the joint. The joint is welded and then, where a groove exists, a filler may be disposed in the groove, and the seams between the filler and the first and second portions of the fabrication preform may be friction stir welded. In some embodiments two portions of a fabrication preform are abutted to form a joint, where the joint may, for example, be a lap joint, a bevel joint or a butt joint. In some embodiments a plurality of passes of a friction stir welding tool may be used, with some passes welding from one side of a fabrication preform and other passes welding from the other side of the fabrication preform.

Feng, Zhili (Knoxville, TN) [Knoxville, TN; David, Stan A. (Knoxville, TN) [Knoxville, TN; Frederick, David Alan (Harriman, TN) [Harriman, TN

2010-07-27T23:59:59.000Z

290

Artificial neural network modelling for evaluating austenitic stainless steel and Zircaloy-2 welds  

Science Journals Connector (OSTI)

Ferrite content in austenitic stainless steel welds is a measure of resistance to solidification cracking. Accurate estimation of ferrite content in austenitic stainless steel welds is important to ensure crack free welds. An artificial neural network (ANN) model has been developed to predict ferrite number with an improved accuracy. Eddy current (EC) testing is attractive due to high sensitivity and versatility for the detection of harmful surface defects. Artificial neural network modelling has been used to process the eddy current data for evaluating the defect depth so that on-line eddy current testing is possible in austenitic stainless steel welds. There is a necessity to develop on-line monitoring methods for evaluation the quality of spacer pad welds in cladding tubes made of Zircaloy-2 used in pressurized heavy water reactors (PHWR). Shear strength values of the individual coins is the measure of the quality of the welds. Prediction of shear strength values of the individual coins ensures their integrity. Artificial neural network model has been developed for prediction of shear strength of spacer pad welds of Zircaloy-2.

M. Vasudevan; B.P.C. Rao; B. Venkatraman; T. Jayakumar; Baldev Raj

2005-01-01T23:59:59.000Z

291

Ultrasonic Evaluation of Two Dissimilar Metal Weld Overlay Specimens  

SciTech Connect (OSTI)

Two dissimilar metal weld (DMW) pipe-to-nozzle specimens were implanted with thermal fatigue cracks in the 13% to 90% through-wall depth range. The specimens were ultrasonically evaluated with phased-array probes having center frequencies of 0.8, 1.0, 1.5, and 2.0 megahertz (MHz). An Alloy 82/182 weld overlay (WOL) was applied and the specimens were ultrasonically re-evaluated for flaw detection and characterization. The Post-WOL flaw depths were approximately 10% to 56% through-wall. This study has shown the effectiveness of ultrasonic examinations of Alloy 82/182 overlaid DMW specimens. Phased-array probes with center frequency in the 0.8- to 1.0-MHz range provide a strong coherent signal but the greater ultrasonic wavelength and larger beam spot size prevent the reliable detection of small flaws. These small flaws had nominal through-wall depths of less than 15% and length in the 50-60 mm (2-2.4 in.) range. Flaws in the 19% and greater through-wall depth range were readily detected with all four probes. At the higher frequencies, the reflected signals are less coherent but still provide adequate signal for flaw detection and characterization. A single inspection at 2.0 MHz could provide adequate detection and sizing information but a supplemental inspection at 1.0 or 1.5 MHz is recommended.

Crawford, Susan L.; Cinson, Anthony D.; Prowant, Matthew S.; Moran, Traci L.; Anderson, Michael T.

2012-06-30T23:59:59.000Z

292

Stainless steel submerged arc weld fusion line toughness  

SciTech Connect (OSTI)

This effort evaluated the fracture toughness of austenitic steel submerged-arc weld (SAW) fusion lines. The incentive was to explain why cracks grow into the fusion line in many pipe tests conducted with cracks initially centered in SAWS. The concern was that the fusion line may have a lower toughness than the SAW. It was found that the fusion line, Ji. was greater than the SAW toughness but much less than the base metal. Of greater importance may be that the crack growth resistance (JD-R) of the fusion line appeared to reach a steady-state value, while the SAW had a continually increasing JD-R curve. This explains why the cracks eventually turn to the fusion line in the pipe experiments. A method of incorporating these results would be to use the weld metal J-R curve up to the fusion-line steady-state J value. These results may be more important to LBB analyses than the ASME flaw evaluation procedures, since there is more crack growth with through-wall cracks in LBB analyses than for surface cracks in pipe flaw evaluations.

Rosenfield, A.R.; Held, P.R.; Wilkowski, G.M. [Battelle, Columbus, OH (United States)

1995-04-01T23:59:59.000Z

293

Microstructural characterization in dissimilar friction stir welding between 304 stainless steel and st37 steel  

SciTech Connect (OSTI)

In the present study, 3 mm-thick plates of 304 stainless steel and st37 steel were welded together by friction stir welding at a welding speed of 50 mm/min and tool rotational speed of 400 and 800 rpm. X-ray diffraction test was carried out to study the phases which might be formed in the welds. Metallographic examinations, and tensile and microhardness tests were used to analyze the microstructure and mechanical properties of the joint. Four different zones were found in the weld area except the base metals. In the stir zone of the 304 stainless steel, a refined grain structure with some features of dynamic recrystallization was evidenced. A thermomechanically-affected zone was characterized on the 304 steel side with features of dynamic recovery. In the other side of the stir zone, the hot deformation of the st37 steel in the austenite region produced small austenite grains and these grains transformed to fine ferrite and pearlite and some products of displacive transformations such as Widmanstatten ferrite and martensite by cooling the material after friction stir welding. The heat-affected zone in the st37 steel side showed partially and fully refined microstructures like fusion welding processes. The recrystallization in the 304 steel and the transformations in the st37 steel enhanced the hardness of the weld area and therefore, improved the tensile properties of the joint. - Highlights: Black-Right-Pointing-Pointer FSW produced sound welds between st37 low carbon steel and 304 stainless steel. Black-Right-Pointing-Pointer The SZ of the st37 steel contained some products of allotropic transformation. Black-Right-Pointing-Pointer The material in the SZ of the 304 steel showed features of dynamic recrystallization. Black-Right-Pointing-Pointer The finer microstructure in the SZ increased the hardness and tensile strength.

Jafarzadegan, M. [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of) [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Feng, A.H. [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China)] [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Abdollah-zadeh, A., E-mail: zadeh@modares.ac.ir [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); Saeid, T. [Advanced Materials Research Center, Sahand University of Technology, P.O. Box: 51335-1996, Tabriz (Iran, Islamic Republic of)] [Advanced Materials Research Center, Sahand University of Technology, P.O. Box: 51335-1996, Tabriz (Iran, Islamic Republic of); Shen, J. [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China)] [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Assadi, H. [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of)] [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of)

2012-12-15T23:59:59.000Z

294

Technical Letter Report, An Evaluation of Ultrasonic Phased Array Testing for Reactor Piping System Components Containing Dissimilar Metal Welds, JCN N6398, Task 2A  

SciTech Connect (OSTI)

Research is being conducted for the U.S. Nuclear Regulatory Commission at the Pacific Northwest National Laboratory to assess the effectiveness and reliability of advanced nondestructive examination (NDE) methods for the inspection of light-water reactor components. The scope of this research encompasses primary system pressure boundary materials including dissimilar metal welds (DMWs), cast austenitic stainless steels (CASS), piping with corrosion-resistant cladding, weld overlays, inlays and onlays, and far-side examinations of austenitic piping welds. A primary objective of this work is to evaluate various NDE methods to assess their ability to detect, localize, and size cracks in steel components that challenge standard and/or conventional inspection methodologies. This interim technical letter report provides a summary of a technical evaluation aimed at assessing the capabilities of phased-array (PA) ultrasonic testing (UT) methods as applied to the inspection of small-bore DMW components that exist in the reactor coolant systems (RCS) of pressurized water reactors (PWRs). Operating experience and events such as the circumferential cracking in the reactor vessel nozzle-to-RCS hot leg pipe at V.C. Summer nuclear power station, identified in 2000, show that in PWRs where primary coolant water (or steam) are present under normal operation, Alloy 82/182 materials are susceptible to pressurized water stress corrosion cracking. The extent and number of occurrences of DMW cracking in nuclear power plants (domestically and internationally) indicate the necessity for reliable and effective inspection techniques. The work described herein was performed to provide insights for evaluating the utility of advanced NDE approaches for the inspection of DMW components such as a pressurizer surge nozzle DMW, a shutdown cooling pipe DMW, and a ferritic (low-alloy carbon steel)-to-CASS pipe DMW configuration.

Diaz, Aaron A.; Cinson, Anthony D.; Crawford, Susan L.; Anderson, Michael T.

2009-11-30T23:59:59.000Z

295

Influence of nondestructive test procedures on detection of stress-corrosion cracks  

SciTech Connect (OSTI)

A weld T joint from a scrapped carbon-steel digester level tank was used to test the efficacy of the nondestructive liquid-penetrant and magnetic-particle test methods commonly used for field detection of stress-corrosion cracks. The tests were conducted using three methods of surface preparation--wire brushing, light grinding, and sandblasting. Light grinding of the surface greatly increased the sensitivity of both the liquid-penetrant and magnetic-particle test methods. The most successful combination was light surface grinding followed by inspection with a fluorescent liquid.

Reid, J.C. (Industrial Nondestructive Testing Ltd., Burnaby, British Columbia (Canada)); Reid, D.C. (MacMillan Bloedel Ltd., Burnaby, British Columbia (Canada))

1993-08-01T23:59:59.000Z

296

Inertia welding for assembly of copper squirrel cages for electric motors  

Science Journals Connector (OSTI)

Abstract The automotive industry is developing designs and manufacturing processes for new generations of electric motors intended for use in hybrid and electric vehicles. There is interest in replacing the aluminum traditionally used in induction motor rotors with copper to improve motor capability. This paper focuses on solid-state welding to join copper end rings to copper spokes in the fabrication of copper rotors. Inertia friction welding was explored to examine weldability of these copper components. A better understanding of inertia welding characteristics will help the advancements in its application for induction rotors. The limitations of this application are discussed.

John S. Agapiou

2014-01-01T23:59:59.000Z

297

Fracture Behavior of a Laser Beam Welded High-strength Al-Zn Alloy  

Science Journals Connector (OSTI)

Abstract Laser beam welding of butt joints made of the newly developed high-strength Al-Zn alloy PA734 is conducted. A new approach of the Helmholtz-Zentrum Geesthacht is used to solve the problems of weldability and softening. The results of the fatigue, fatigue crack propagation and fracture toughness tests are discussed relating to the microstructural characteristics and the mechanical properties of the laser welded joints and compared to the base material. The obtained data can be used for the assessment of the damage tolerance behaviour of the laser welded integral aircraft structures made of Al-Zn alloys.

J. Enz; H. Iwan; S. Riekehr; V. Ventzke; N. Kashaev

2014-01-01T23:59:59.000Z

298

FUNDAMENTAL STUDY OF MICRO-DEFECTS IN ELECTROPOLISHED EB-WELDED AND HYDROFORMED SRF ACCELERATING STRUCTURES  

SciTech Connect (OSTI)

In the area of niobium elecroploshing fundamentals, we focused on undersanding the influence of the surface topology, and geometry (with effects from gravity included. The formation of a viscous film is essential for the electropolishing process to take place. The exact nature and composition of the film formed on niobium is still unknown because of its solubility in the electrolyte. Extensive pitting may take place at surface where a stable film cannot form. This has to be taken into consideration while determining the speed with which the SRF cavities are rotated while EP. Hydrodynamic aspects must be taken into consideration while optimizing the polishing parameters. There is improvement in surface finish with polishing time. There is a huge change in surface quality when the EP time is increased from 2 hours to 4 hours but not much change takes place when the time is further increased to 6 hours. So keeping the economic points in view, about 100 um defect layer removal may be sufficient to get the desired performance. In the area of Electropolishing of untreated and treated niobium with Weld Joints we studied untreated and treated Nb, especially for the heat affected areas next to welded bumps, electropolished for different durations. The electropolishing of the untreated Nb caused the formation of pits on the surface at about 15 min but they disappeared when the electropolishing duration was more than 15 min. Electropolishing for 120 min smoothened the surface of untreated Nb by levelling the surface, but the severe formation of pits on the whole surface was found after 240 min. The treatment of Nb significantly changed the Nb surface morphology which was covered by grains of different size that looked light or dark in the optical microscope. The treated Nb was susceptible to pitting during the entire electropolishing starting from 15 min and the dark grains had more susceptibility to pitting than the light grains. In addition, electropolishing for 240 min again resulted in severe pit formation. In the area of Bulge test and microstructure studies, we worked to create a useful constitutive relationship for the complex stress state that accompanies SRF cavity formation. To do so, bulge tests were performed on Cu and Nb tube samples that exhibited the greatest degrees of uniaxial elongation after HT. The data from the bulge tests and an accompanying set of tensile tests provided input to a finite-element model that recreated the bulge tests numerically. As expected the model based on the bulge test results fit the experimental data well at least at low stress levels safely below the bursting pressure. Not so for that based on the tensile results. The results of the study emphasize the importance of for bulge testing rather than tensile testing when deriving the constitutional relationships eventually needed for modelling the hydroforming of Nb SRF cavities.

Sumption, Mike

2014-08-29T23:59:59.000Z

299

Weldability and weld performance of a special grade Hastelloy-X modified for high-temperature gas-cooled reactors  

SciTech Connect (OSTI)

The characteristics of weld defects in the electron beam (EB) welding and the tungsten inert gas (TIG) arc welding for Hastelloy-XR, a modified version of Hastelloy-X, are clarified through the bead-on-plate test and the Trans-Varestraint test. Based on the results, weldabilities on EB and TIG weldings for Hastelloy-XR are discussed and found to be almost the same as Hastelloy-X. The creep rupture behaviors of the welded joints are evaluated by employing data on creep properties of the base and the weld metals. According to the evaluation, the creep rupture strength of the EB-welded joint may be superior to that of the TIG-welded joint. The corrosion test in helium containing certain impurities is conducted for the weld metals. There is no significant difference of such corrosion characteristics as weight gain, internal oxidation, depleted zone, and so on between the base and the weld metals. Those are superior to Hastelloy-X.

Shimizu, S.; Mutoh, Y.

1984-07-01T23:59:59.000Z

300

Stress Test | Open Energy Information  

Open Energy Info (EERE)

Stress Test Stress Test Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Stress Test Details Activities (1) Areas (1) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Testing Techniques Parent Exploration Technique: Well Testing Techniques Information Provided by Technique Lithology: Stratigraphic/Structural: Fracture distribution and ambient tectonic stresses Hydrological: Fluid flow direction Thermal: Dictionary.png Stress Test: A geologic stress analysis based on images of a borehole wall and hydraulic fracturing tests to characterize fracture orientations and stress magnitudes in order to identify stress planes and zones of potential permeability. Other definitions:Wikipedia Reegle

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

A Submarine Welded Ignimbrite-Crystal-Rich Sandstone Facies Association In  

Open Energy Info (EERE)

Submarine Welded Ignimbrite-Crystal-Rich Sandstone Facies Association In Submarine Welded Ignimbrite-Crystal-Rich Sandstone Facies Association In The Cambrian Tyndall Group, Western Tasmania, Australia Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Submarine Welded Ignimbrite-Crystal-Rich Sandstone Facies Association In The Cambrian Tyndall Group, Western Tasmania, Australia Details Activities (0) Areas (0) Regions (0) Abstract: Three occurrences of rhyolitic welded ignimbrite are intercalated within a submarine, below-storm-wave-base sedimentary succession in the Cambrian Tyndall Group, Mount Read Volcanics, western Tasmania. These occurrences are closely associated with very thick crystal-rich sandstone facies that is present at this stratigraphic level throughout the Tyndall Group. This facies is interpreted to comprise deposits from syn-eruptive,

302

E-Print Network 3.0 - aluminum alloy welds Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

991999 PII: S0957-0233(04)74770-0 Summary: in aluminum alloys Weld. J. 72 49-51 8 Wikle H C, Kottilingam S, Zee R H and Chin B A 2001 Infrared sensing... ) 991-999 PII:...

303

E-Print Network 3.0 - arc welding robot Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

robot Search Powered by Explorit Topic List Advanced Search Sample search results for: arc welding robot Page: << < 1 2 3 4 5 > >> 1 ORIGINAL ARTICLE Development of a mobile...

304

Cracked lifting lug welds on ten-ton UF{sub 6} cylinders  

SciTech Connect (OSTI)

Ten-ton, Type 48X, UF{sub 6} cylinders are used at the Portsmouth Gaseous Diffusion Plant to withdraw enriched uranium hexafluoride from the cascade, transfer enriched uranium hexafluoride to customer cylinders, and feed enriched product to the cascade. To accomplish these activities, the cylinders are lifted by cranes and straddle carriers which engage the cylinder lifting lugs. In August of 1988, weld cracks on two lifting lugs were discovered during preparation to lift a cylinder. The cylinder was rejected and tagged out, and an investigating committee formed to determine the cause of cracking and recommend remedial actions. Further investigation revealed the problem may be general to this class of cylinder in this use cycle. This paper discusses the actions taken at the Portsmouth site to deal with the cracked lifting lug weld problem. The actions include inspection activities, interim corrective actions, metallurgical evaluation of cracked welds, weld repairs, and current monitoring/inspection program.

Dorning, R.E. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States)

1991-12-31T23:59:59.000Z

305

Vehicle Technologies Office Merit Review 2014: On-Line Weld NDE with IR Thermography  

Broader source: Energy.gov [DOE]

Presentation given by Oak Ridge National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about on-line weld...

306

Test to Determine Margin-to-Failure for Hy-100 Steel with Undermatched Welds  

SciTech Connect (OSTI)

This test program was undertaken to determine the flaw tolerance and to quantify the strength margin-to-failure of high yield strength steel fillet welded specimens. The tests demonstrate adequate margin-to-failure for HY-100 specimens fabricated with matched welding systems. In the use of high yield (HY) steel materials in designs required to accommodate rapidly applied dynamic loads, the concern was raised where the possibility of decreased flaw tolerance and premature failure by unstable ductile tearing could limit their use. Tests were developed and conducted to demonstrate adequate margin-to-failure in HY-100 fillet and partial penetration welded structures. In addition, inelastic analytical predictions were performed to assess the accuracy of such predictive tools compared to actual test data. Results showed that adequate margin-to-failure exists when using matched welding systems.

K.R. Arpin; T.F. Trimble

2003-04-01T23:59:59.000Z

307

Welding of dissimilar alloys for high temperature heat exchangers for SOFC  

SciTech Connect (OSTI)

Reduction in the cost of balance of plant applications is one of the top priority focus areas for the successful implementation of solid oxide fuel cell technology. High temperature heat exchangers are employed to heat cathode air utilizing either hot gases coming from the anode side of the stack or other hot gases generated by external processes. In order to reduce the cost of heat exchangers, it may be necessary to apply several different materials, each in a different temperature zone, for the construction of the heat exchanger. This technique would require the joining of dissimilar materials in the construction. In this work, welding of commercial candidate dissimilar materials is explored. Filler materials were identified using equilibrium phase diagrams and thermodynamic simulation software. Autogenous welding was performed and the welding defects were characterized. Finally, experimental weld microstructures were compared to phases predicted by the simulations.

Wilson, R.D.; Hatem, J.; Dogan, O.N.; King, P.E.

2006-10-01T23:59:59.000Z

308

Wear resistance of laser cladding and plasma spray welding layer on stainless steel surface  

Science Journals Connector (OSTI)

The effect of coatings, which are formed with laser cladding and plasma spray welding on 1Cr18Ni9Ti base metal, on wear resistance is studied, A 5-kW transverse flowing CO2 laser...

Wang, Xinlin; Shi, Shihong; Zheng, Qiguang

2004-01-01T23:59:59.000Z

309

Vehicle Technologies Office Merit Review 2014: Collision Welding of Dissimilar Materials by Vaporizing Foil Actuator  

Broader source: Energy.gov [DOE]

Presentation given by The Ohio State University at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about collision welding...

310

Study on Sub-sea Pipelines Hyperbaric Welding Repair under High Air Pressures  

Science Journals Connector (OSTI)

Most Chinese sub-sea pipelines are buried in Bohai Sea less than ... are widely used For the application of offshore pipelines repair, the hyperbaric TIG welding process under high...

Canfeng Zhou; Xiangdong Jiao; Long Xue

2011-01-01T23:59:59.000Z

311

Improvement of resistance to hydrogen induced cracking in electric resistance welded pipes fabricated with slit coils  

Science Journals Connector (OSTI)

The optimization of electric resistance welding (ERW) conditions was studied to improve the resistance to hydrogen induced cracking (HIC) at ... Furthermore, for a satisfactory level of HIC resistance, the fracti...

Hyun Uk Hong; Jong Bong Lee; Ho Jin Choi

2009-02-01T23:59:59.000Z

312

Electric Resistance Welded Steels for Normalized N-80 Oil and Gas Well Tubulars  

Science Journals Connector (OSTI)

This paper reports the development and successful commercialization of a manganese-molybdenum steel for use in the production of normalized electric resistance welded N-80 casing and tubing. The...

David L. Sponseller; Thomas B. Cox; Evan J. Vineberg

1984-06-01T23:59:59.000Z

313

Hydrogen storage in heat welded random CNT network structures  

Science Journals Connector (OSTI)

Abstract The objective of this study is to investigate hydrogen storage capability of heat welded random carbon nanotube (CNT) network structures. To achieve this objective, different three-dimensional random CNT network structures are generated by using a stochastic algorithm and molecular dynamic simulations. The interaction of CNT networks with hydrogen molecules is then examined via grand canonical Monte Carlo calculations. Hydrogen adsorption capacity of CNT networks having an arbitrarily natured morphology, adjustable porous structure and large surface ratio is investigated. The results show that if cross link density of random CNT networks decreases, hydrogen storage capability of CNT networks increases in terms of the gravimetric capacity. It is observed that random CNT networks could uptake 8.85wt.% hydrogen at 77K and this result is very comparable with the results reported in literature where generally ideal ordered nanostructures having no topological irregularities are considered.

Zeynel Ozturk; Cengiz Baykasoglu; Alper T. Celebi; Mesut Kirca; Ata Mugan; Albert C. To

2014-01-01T23:59:59.000Z

314

Friction welded nonconsumable electrode assembly and use thereof for electrolytic production of metals and silicon  

DOE Patents [OSTI]

A nonconsumable electrode assembly suitable for use in the production of metal by electrolytic reduction of a metal compound dissolved in a molten salt, the assembly comprising a metal conductor and a ceramic electrode body connected by a friction weld between a portion of the body having a level of free metal or metal alloy sufficient to effect such a friction weld and a portion of the metal conductor.

Byrne, Stephen C. (Monroeville, PA); Ray, Siba P. (Pittsburgh, PA); Rapp, Robert A. (Columbus, OH)

1984-01-01T23:59:59.000Z

315

Environment of deposition of the Permian Lyons Sandstone at Black Hollow Field, Weld County, Colorado  

E-Print Network [OSTI]

ENVIRONMENT OF DEPOSITION OF THE PERMIAN LYONS SANDSTONE AT BLACK HOLLOW FIELD, WELD COUNTY, COLORADO A Thesis by DAVID MICHAEL FRANK Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER QF SCIENCE August 1984 Major Subject: Geology ENVIRONMENT OF DEPOSITION OF THE PERMIAN LYONS SANDSTONE AT BLACK HOLLOW FIELD, WELD COUNTY, COLORADO A Thesis by DAVID MICHAEL FRANK Approved as to style and content by: R. R. Berg...

Frank, David Michael

2012-06-07T23:59:59.000Z

316

Eutectic structures in friction spot welding joint of aluminum alloy to copper  

SciTech Connect (OSTI)

A dissimilar joint of AA5083 Al alloy and copper was produced by friction spot welding. The Al-MgCuAl{sub 2} eutectic in both coupled and divorced manners were found in the weld. At a relatively high temperature, mass transport of Cu due to plastic deformation, material flow, and atomic diffusion, combined with the alloy system of AA5083 are responsible for the ternary eutectic melting.

Shen, Junjun, E-mail: junjun.shen@hzg.de; Suhuddin, Uceu F. H.; Cardillo, Maria E. B.; Santos, Jorge F. dos [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Materials Mechanics, Solid-State Joining Processes, Max-Planck-Str. 1, 21502 Geesthacht (Germany)

2014-05-12T23:59:59.000Z

317

The structure and properties of weld lines in injection molded thermoplastics  

E-Print Network [OSTI]

THE STRUCTURE AND PROPERTIES OF WELD LINES IN INJECTION MOLDED THEBMOPLAST1CS A Thesis by ALI IHSAN MANISALI Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OP... SCIENCE May 1980 Major Subject: Mechanical Engineering THE STRUCTURE AND PROPERTZES OF WELD LINES IN INJECTION MOLDED THERMOPLASTICS A Thesis by ALI IHSAN MANISALI Approved as to style and content by: (Chairman of Committee) (H of Department...

Manisali, Ali Ihsan

2012-06-07T23:59:59.000Z

318

Minimum thickness for circumferential sleeve repair fillet welds in corroded gas pipelines  

Science Journals Connector (OSTI)

The minimum weldable pipe wall thickness for sleeve repair welds is numerically assessed in this work, as a function of pressure during the welding operations of a corroded gas pipeline, according to the approach by Battelle. The minimum weldable thickness is found to increase when the flow rate of the transported gas in the section being repaired increases. Integrity of the repairs is assessed, and alternative measures to momentarily increase the flow in the area of the repair are evaluated.

A.P Cisilino; M.D Chapetti; J.L Otegui

2002-01-01T23:59:59.000Z

319

Program Managers  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Program Managers Program Managers Enabling remarkable discoveries and tools that transform our understanding of energy and matter and advance national, economic, and energy...

320

Atom probe field-ion microscopy investigation of nickel base superalloy welds  

SciTech Connect (OSTI)

Microstructure development and elemental partitioning between {gamma} and {gamma}{prime} were measured in PWA-1480 electron beam welds and CMSX-4 pulsed-laser welds. In PWA-1480 EB welds, eutectic {gamma}{prime} phases were observed along the dendritic boundaries. The elemental partitioning between {gamma} and {gamma}{prime} was found to be similar to that in PWA-1480 base metal. In CMSX-4 pulsed laser welds, negligible eutectic {gamma}{prime} was observed. In addition, fine and irregularly shaped {gamma}{prime} precipitates were observed. The elemental partitioning between {gamma} and {gamma}{prime} was found to be different from that measured in the base metal. Large concentration gradients were observed in the {gamma} phase. The {gamma}{prime} precipitation kinetics in CM247DS alloy was measured using dilatometry and showed differences with different cooling rates. The microstructural investigations showed that at large undercoolings the number density of {gamma}{prime} precipitates increased and led to a finer size. This supports the microstructure development observations in PWA-1480 and CMSX-4 welds. Thermodynamic and kinetic calculations for the Ni-Al-Cr alloy system showed that as the cooling rate increases, the {gamma}{prime} growth leads to large concentration gradients in the {gamma} phase. The calculations agree with the atom probe results from PWA-1480 and CMSX-4 welds.

Babu, S.S.; David, S.A.; Vitek, J.M.; Miller, M.K.

1998-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Microstructural characterization of dissimilar welds between alloy 800 and HP heat-resistant steel  

SciTech Connect (OSTI)

In this study, dissimilar welds between HP heat-resistant steel and Incoloy 800 were made with four different filler materials including: 309 stainless steel and nickel-based Inconel 82, 182 and 617. The microstructure of the base metals, weld metals and their interfaces were characterized by utilizing optical and scanning electron microscopy. Grain boundaries migration in the weld metals was studied. It was found that the migration of grain boundaries in the Inconel 82 weld metal was very extensive. Precipitates of TiC and M{sub 23}C{sub 6} (M = Cr and Mo) in the Inconel 617 weld metal are identified. The necessary conditions for the formation of cracks close to the fusion line of the 309-HP joints are described. Furthermore unmixed zone near the fusion line between HP steel base metal and Inconel 82 weld metal is discussed. An epitaxial growth is characterized at the fusion line of the 309-Alloy 800 and Inconel 617-Alloy 800 joints.

Dehmolaei, R. [Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Shamanian, M. [Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of)], E-mail: shamanian@cc.iut.ac.ir; Kermanpur, A. [Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of)

2008-10-15T23:59:59.000Z

322

Corrosion of nickel and Monel welds of steel in chlorine trifluoride  

SciTech Connect (OSTI)

Failures in the weld areas of nickel-plated steel pipe carrying chlorine trifluoride, ClF/sub 3/, prompted this investigation to determine the effect of weld composition on corrosion by ClF/sub 3/. Monel/steel and nickel/steel alloys of composition to simulate weld overlays were tested to determine their corrosion rates in ClF/sub 3/ at 200/degree/F and 300/degree/F. For both nickel/steel and Monel/steel, the corrosion rate was higher at the higher temperature. For nickel/steel alloys at compositions up to 50% iron, which would cover a range considered normal for welding, the corrosion rate would be within acceptable limits. For Monel/steel alloys, compositions up to 35% iron have an acceptable corrosion rate. Above this, the corrosion would be greater than a tolerable amount. It should pose no problem to keep the heat input to the weld low enough to produce a Monel weld with an iron content below 35%. 2 refs., 5 figs., 2 tabs.

Fout, S.L.

1988-07-25T23:59:59.000Z

323

Capabilities of Ultrasonic Techniques for Far-Side Examinations of Austenitic Stainless Steel Piping Welds.  

SciTech Connect (OSTI)

A study was conducted to assess the ability of advanced ultrasonic techniques to detect and accurately length-size flaws from the far-side of wrought austenitic piping welds. Far-side inspections of nuclear system piping welds are currently performed on a best effort basis and do not conform to ASME Code Section XI Appendix VIII performance demonstration requirements. For this study, austenitic stainless steel specimens with flaws located on the far-side of full penetration structural welds were used. The welds were fabricated with varied welding parameters to simulate as-built conditions in the components, and were examined with phased array technology at 2.0 MHz, and low-frequency/Synthetic Aperture Focusing Technique (SAFT) methods in the 250-400 kHz regime. These results were compared to conventional ultrasonic techniques as a baseline. The examinations showed that both phased-array and low-frequency/SAFT were able to reliably detect and length-size, but not depth size, notches and implanted fatigue cracks through the welds.

Anderson, Michael T.; Diaz, Aaron A.; Cumblidge, Stephen E.; Doctor, Steven R.

2007-01-01T23:59:59.000Z

324

Ultra-narrow gap laser welding of BeAl alloys. Final report  

SciTech Connect (OSTI)

The original scope of the project was to develop a method to enhance the laser welding of BeAl alloys by the use of weld joint designs based on the principals of non-imaging optics. The projected three year program focused on the development of geometric optical models which predict the trapping of laser energy within the weld joint and experimental validation of these models. The first year was fully funded, meeting all expectations and deliverables for the demonstration of the method for aluminum only. The second year funding levels did not allow any work to be done at Los Alamos. OptiCAD continued with model development with a change in scope to model the laser welding requirements of ongoing weapons related programs which could provide data for model validation. The project ended at the end of FY97 without funding a third year and never reaching the goal of welding beryllium, as a result. Despite the poor funding situation, original quality process research was accomplished and reported as described in the three technical reports of Appendix A. Solid technical contribution, directly applicable to weapons programs is evidenced by the inclusion of an optically designed laser weld joint being specified on a LANL drawing of an aluminum subassembly.

Milewski, J.O. [Los Alamos National Lab., NM (United States); Sklar, E. [OptiCAD Corp., Santa Fe, NM (United States)

1998-11-01T23:59:59.000Z

325

Weldability and keyhole behavior of Zn-coated steel in remote welding using disk laser with scanner head  

Science Journals Connector (OSTI)

Zinc-coated steels are widely used in automobile bodies. Laser welding which offers a lot of advantages over the conventional welding with metal active gas welding CO2 arc etc. in terms of improved weld quality high-speed and easy automation has been developed for cars. However in laser lap welding of zinc-coated steel sheets without gaps defects such as underfilled beads or porosity were easily formed due to higher pressure of zinc vapor trapped in the molten pool because of the lower boiling point of zinc (1180?K) with respect to the melting point of steel (Fe 1803?K). Laser lap welding results of two Zn-coated steel sheets have been reported. However there are not enough data for welding of three Zn-coated steel sheets. Therefore to understand laser lap weldability of three Zn-coated steel sheets lap welding of two or three sheets with and without gaps was performed using 16?kW disk laser apparatus with a scanner head and molten pool motions spattering and keyhole behavior during welding were observed by high-speed video cameras and x-ray transmission real-time imaging apparatus. Lap welding of three steel sheets was difficult but acceptably good welds were produced in sheets with upper and lower gaps of 0.1 and 0.1?mm 0.1 and 0.2?mm or 0.2 and 0.1?mm respectively. Bubble generation leading to porosity formation was observed and it was confirmed that welding phenomena were different depending upon the gap levels.

Jong-Do Kim

2013-01-01T23:59:59.000Z

326

Conference Management  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

To establish requirements and responsibilities with respect to managing conferences sponsored by the Department of Energy (DOE) or by DOE management and operating contractors and other contractors who perform work at DOE-owned or -leased facilities, including management and integration contractors and environmental restoration management contractors (when using funds that will be reimbursed by DOE). Cancels DOE N 110.3.

1999-11-03T23:59:59.000Z

327

Management Staff | Central Fabrication Services | Brookhaven National  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Management Staff Management Staff Al Farland Al Farland Central Fabrication Services General Supervisor Welding, Sheet Metal, and Maintenance Metal Work Supervisor Al Farland joined the Laboratory in 1978 with over 20 years of experience in the metal fabrication industry. Al worked on the floor before becoming a supervisor and is familiar and responsible for the Central Fabrication Services group. Phone: (631) 344-8462 Fax: (631) 344-7208 Email: farland@bnl.gov Kevin Campbell Kevin Campbell Machine Shop Supervisor Kevin Campbell came to the Laboratory in 2008 as a programmer/planner/estimator and has since been promoted to Machine Shop Supervisor. Kevin is responsible for Machine shop operations. Phone: (631) 344-3498 Fax: (631) 344-7208 Email: kcampbell@bnl.gov Chris Manning Chris Manning

328

Prediction of failure behavior of a welded pressure vessel containing flaws during a hydrogen-charged burst test  

SciTech Connect (OSTI)

An industry-government collaborative program was carried out with an aim to promoting the acceptance of fracture mechanics based fitness-for-service assessment methodology for a service-damaged pressure vessel. A collaborative round robin exercise was carried out to predict the fracture behavior of a vessel containing hydrogen damage, fabrication related lack-of-fusion defects, an artificially induced fatigue crack and a localized thinned area. The fracture assessment procedures used include the US ASME Material Property Council`s PREFIS Program based on the British Standard (BS) Published Document (PD) 6493, ASME Section XI and The Central Electricity Generating Board (CEGB) R6 approach; The welding Institute (TWI) CRACKWISE program (based on BS PD6493 Level 2 approach), a variant of the R6 approach, J-tearing instability approaches, various J-estimation schemes, LEFM approach and simplified stress analysis. Assessments were compared with the results obtained from a hydrogen charged burst test of the vessel. Predictions, based on the J-tearing approach, compared well with the actual burst test results. Actual burst pressure was about five times the operating pressure.

Bhuyan, G.S. [Powertech Labs. Inc., Surrey, British Columbia (Canada); Sperling, E.J. [Amoco Corp., Naperville, IL (United States); Shen, G. [CANMET, Ottawa, Ontario (Canada). Metals Technology Labs.; Yin, H. [Mobil Research and Development Corp., Farmers Branch, TX (United States); Rana, M.D. [Praxair, Inc., Tonawanda, NY (United States)

1996-12-01T23:59:59.000Z

329

Prediction of failure behavior of a welded pressure vessel containing flaws during a hydrogen-charged burst test  

SciTech Connect (OSTI)

An industry-government collaborative program was carried out with an aim to promoting the acceptance of fracture mechanics-based fitness-for-service assessment methodology for a service-damaged pressure vessel. A collaborative round robin exercise was carried out to predict the fracture behavior of a vessel containing hydrogen damage, fabrication-related lack-of-fusion defects, an artificially induced fatigue crack, and a localized thinned area. The fracture assessment procedures used include the US ASME Material Property Council`s PREFIS Program based on the British Standard (BS) Published Document (PD) 6493, ASME Section XI and The Central Electricity Generating Board (CEGB) R6 approach, The Welding Institute (TWI) CRACKWISE program (based on BS PD6493 Level 2 approach), a variant of the R6 approach, J-tearing instability approaches, various J-estimation schemes, LEFM approach, and simplified stress analysis. Assessments were compared with the results obtained from a hydrogen-charged burst test of the vessel. Predictions, based on the J-tearing approach, compared well with the actual burst test results. Actual burst pressure was about five times the operating pressure.

Bhuyan, G.S. [Powertech Labs Inc., Surrey, British Columbia (Canada); Sperling, E.J. [BP-Amoco, Calgary, Alberta (Canada); Shen, G. [CANMET, Ottawa, Ontario (Canada). Metals Technology Labs.; Yin, H. [Mobil Technology Co., Dallas, TX (United States); Rana, M.D. [Praxair, Inc., Tonawanda, NY (United States)

1999-08-01T23:59:59.000Z

330

Scaling Up From Material Fracture Resistance to Fracture Representation in Welded Structures  

Science Journals Connector (OSTI)

Abstract This paper presents a procedure to integrate the material fracture resistance, quantified by the experimentally measured J-R curve, in the fracture representation of welded tubular joints. This method incorporates a validated ?-approach to estimate the elastic-plastic crack driving forces for fatigue cracks initiated at hot-spot locations of the welded tubular joints. The proposed scaling approach predicates on the fundamental assumption that the fracture resistance measured from the J-R curve, with a small and limited amount of crack extension, characterizes the material fracture resistance independent of the specimen geometry. The maximum crack extension allowed in the material testing standard marks the transferability limit of the material J-R curve to the welded joints. The extension of the fatigue crack in the welded joint leads to an increasing fracture resistance and a decreasing load resistance due to the increased crack area. The validation of this approach utilizes load-deformation responses from two scales of experimental specimens: 1) the large-scale welded tubular connection with a fatigue pre-crack; and 2) the large-scale frame test with predominantly fracture failure at the welded tubular joint. The load-deformation relationship based on the proposed scheme presents a close agreement with the experimentally recorded load-deformation behavior of the welded tubular joints. The proposed approach, when integrated into the push-over analyses of the large-scale tubular frames, presents an accurate estimation on the deformation level at which unstable fracture failure occurs and a conservative prediction of the corresponding failure load.

Xudong Qian; Yang Zhang; Ya Li

2014-01-01T23:59:59.000Z

331

Assessment of Hydrogen Cracking Risk in Multipass Weld Metal of 2.25Cr-1Mo-0.25V-TiB (T24) Boiler Steel  

Science Journals Connector (OSTI)

Welding modern high-strength steel with low carbon and impurity contents, preheating may be dictated by cracking sensitivity of the weld metal instead of the HAZ. Standardised methods are mostly developed for ...

P. Nevasmaa; A. Laukkanen

2005-07-01T23:59:59.000Z

332

Research Facility Climate change and environmental stresses placed by humans on plants,  

E-Print Network [OSTI]

among biological organisms in air, soil and water, particularly in light of climate and environmental, biodiversity, biotechnologies in medicine and environmental risk management · Provides researchersResearch Facility Climate change and environmental stresses placed by humans on plants, animals

Denham, Graham

333

Stress-corrosion cracking of steels in ammonia with consideration given to OTEC design: a survey  

SciTech Connect (OSTI)

Carbon steel, alloy steel, and high-strength, quenched and tempered steel, when under applied or residual stress and especially when cold formed and/or welded without subsequent thermal stress relief, are subject to failure by stress-corrosion cracking (SCC) in air-contaminated dry ammonia. Water as well as hydrazine when present in small amounts have been shown to be effective inhibitors in an all steel system. Galvanic corrosion between dissimilar metals and/or accelerated failure by SCC of stressed steel as a result of galvanic coupling may be of concern. Where water has proven effective as an inhibitor of SCC in an all steel system, it may not be adequate in a mixed metal system. With aluminum tubes, the tube sheet will either have to be solid aluminum, aluminum clad steel or some nonconductive coating will be necessary to effectively remove the cathodic alloy from the galvanic circuit. Research is required to determine the severity of the coupling effect between dissimilar alloys in ammonia under OTEC conditions; especially the possibility of accelerated SCC failures of stressed steel where the presence of an inhibitor in the ammonia may not be sufficient to override the galvanic coupling effect.

Teel, R.B.

1980-03-01T23:59:59.000Z

334

Analysing Web-Orchestrations Under Stress Using Uncertainty Profiles  

Science Journals Connector (OSTI)

......even broken). Risk management is a well-established...unpredictable surges in demand can occur. In this paper...stress due to over-demand, service improve- ment...interaction between over-demand and elas- ticity. We...Service calls may induce side effects. The orchestration......

Joaquim Gabarro; Maria Serna; Alan Stewart

2014-11-01T23:59:59.000Z

335

Thermal stresses in laminated beams  

E-Print Network [OSTI]

24. Normal Stress Distribution for a Cantilever Laminated Beam, T-Z sinzx/L --------------- 58 m. i 25. Axial Stress Distribution for a Cantilever Laminated Bearq, T-T (2z/8+1) 2 mi 27. Normal Stress Distribution for ("/L) ? ---- 6 O 2 a... 80 100 Stress o (psi) xz. i Fig. 14. Normal Stress Distribution for a Simply-Supported Laminated Beam, T=z (2z/H+1) (x/L) 2 2 m. 1 6 4 x Classical Solution o Present Solution Load: Sinusoidal I F 0 100 200 300 400 Stress c (ps&) XX. 1 500...

Marcano, Victor Manuel

2012-06-07T23:59:59.000Z

336

Ozone and ethylene stress  

Science Journals Connector (OSTI)

... SIR"In a recent News and Views article1 "Adding ethylene to injury", M. Unsworth discussed the results of Mehlhorn and Wellburn2, who reported ... M. Unsworth discussed the results of Mehlhorn and Wellburn2, who reported that both endogenous ethylene (a stress-hormone) and exogenous ozone are cooperating prerequisites for injury to pea plants ...

E. F. ELSTNER

1987-08-06T23:59:59.000Z

337

Characterization of Friction Stir Welded Tubes by Means of Tube Bulge Test  

SciTech Connect (OSTI)

Mechanical properties of friction stir welded joints are generally evaluated by means of conventional tensile test. This testing method might provide insufficient information because maximum strain obtained in tensile test before necking is small; moreover, the application of tensile test is limited when the joint path is not linear or even when the welds are executed on curved surfaces. Therefore, in some cases, it would be preferable to obtain the joints properties from other testing methods. Tube bulge test can be a valid solution for testing circumferential or longitudinal welds executed on tubular workpieces. The present work investigates the mechanical properties and the formability of friction stir welded tubes by means of tube bulge tests. The experimental campaign was performed on tubular specimens having a thickness of 3 mm and an external diameter of 40 mm, obtained starting from two semi-tubes longitudinally friction stir welded. The first step, regarding the fabrication of tubes, was performed combining a conventional forming process and friction stir welding. Sheets in Al-Mg-Si-Cu alloy AA6060 T6 were adopted for this purpose. Plates having a dimension of 225x60 mm were bent (with a bending axis parallel to the main dimension) in order to obtain semi-tubes. A particular care was devoted to the fabrication of forming devices (punch and die) in order to minimize the springback effects. Semi-tubes were then friction stir welded by means of a CNC machine tool. Some preliminary tests were carried out by varying the welding parameters, namely feed rate and rotational speed. A very simple tool having flat shoulder and cylindrical pin was used. The second step of the research was based on testing the welded tubes by means of tube bulge test. A specific equipment having axial actuators with a conical shape was adopted for this study. Some analyses were carried out on the tubes bulged up to a certain pressure level. In particular, the burst pressure and the wall thickness were measured for each tested tube.

D'Urso, G.; Longo, M.; Giardini, C. [University of Bergamo-Dept. of Design and Technologies-Italy-Viale Marconi 5, 24044 Dalmine (Italy)

2011-05-04T23:59:59.000Z

338

Soft zone formation in dissimilar welds between two Cr-Mo steels  

SciTech Connect (OSTI)

Two dissimilar weldments between 9Cr-1Mo and 2.25Cr-1Mo ferritic steels have been characterized for their microstructural stability during various postweld heat treatments (PWHTs). The samples for the investigation were extracted from bead-on-plate weldments made by depositing 2.25Cr-1Mo weld metal on 9Cr-1Mo base plate and vice versa. Subsequent application of PWHT resulted in the formation of a soft zone in the low Cr ferritic steel weld or base plate. A carbide-rich hard zone, adjoining the soft zone, was also detected in the high Cr side of the weldment. Unmixed zones in the weld metal provided additional soft and hard zones in the weld metals. The migration of carbon from low-Cr steel to high-Cr steel, driven by the carbon activity gradient, has been shown to be responsible for the formation of soft and hard zones. A carbon activity diagram for 2.25Cr-1Mo/9Cr-1Mo weldments has been proposed to aid in the selection of welding consumables for reducing or preventing the soft zone formation.

Albert, S.K.; Gill, T.P.S.; Tyagi, A.K.; Mannan, S.L.; Rodriguez, P. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Kulkarni, S.D. [Indian Inst. of Tech., Bombay (India)

1997-03-01T23:59:59.000Z

339

Microstructural Characterization of 6061 Aluminum to 304L Stainless Steel Inertia Welds  

SciTech Connect (OSTI)

'Microstructural characterization of 6061-T6 aluminum-to-Type 304L stainless steel inertia welds provided a technical basis to conclude that transition joints fabricated from such welds should satisfactorily contain helium/hydrogen gas mixtures. This conclusion is based on the lack of semi-continuous alignments of particles and/or inclusions at, or near, the aluminum-to-stainless steel interface. These dissimilar metal transition joints play a key role in the operation of an accelerator driven, spallation neutron source designed for the production of tritium. The Accelerator Production of Tritium system will produce tritium through neutron interactions with 3He gas contained in water-cooled, 6061-T6 aluminum pressure tubes. Current design concepts include thousands of thin-walled pressure tubes distributed throughout a number of aluminum-clad, lead-filled, blanket modules. The aluminum pressure tubes are connected to a tritium extraction and purification system through a stainless steel manifold. The transition from aluminum to stainless steel is made via transition joints machined from the aluminum-to-stainless steel inertia welds. The paper describes the baseline microstructural characterization of the welds, including optical, scanning and transmission electron microscopy and uses that characterization to evaluate potential gas leakage across the weld.'

Dunn, K.A.

1999-09-29T23:59:59.000Z

340

Characterization of microstructures and mechanical properties of Inconel 617/310 stainless steel dissimilar welds  

SciTech Connect (OSTI)

The microstructure and mechanical properties of Inconel 617/310 austenitic stainless steel dissimilar welds were investigated in this work. Three types of filler materials, Inconel 617, Inconel 82 and 310 austenitic stainless steels were used to obtain dissimilar joint using the gas tungsten arc welding process. Microstructural observations showed that there was no evidence of any possible cracking in the weldments achieved by the nickel-base filler materials. The welds produced by 617 and 310 filler materials displayed the highest and the lowest ultimate tensile strength and total elongation, respectively. The impact test results indicated that all specimens exhibited ductile fracture. Among the fillers, Inconel 617 exhibited superlative fracture toughness (205 J). The mechanical properties of the Inconel 617 filler material were much better than those of other fillers. - Research Highlights: {yields} A fine dendritic structure was seen for the Inconel 617 weld metal. {yields} A number of cracks were initiated when the 310 SS filler metal was used. {yields} All welded samples showed ductile fracture. {yields} The Inconel 617 filler material presents the optimum mechanical properties.

Shah Hosseini, H., E-mail: h.shahhosseini@ma.iut.ac.ir; Shamanian, M.; Kermanpur, A.

2011-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Evaluation on defect in the weld of stainless steel materials using nondestructive technique  

Science Journals Connector (OSTI)

Abstract The objective of this study is to evaluate the elastic wave's characteristic on the crack in the weld of stainless steel materials using guided wave and acoustic emission, nondestructive tests. The stainless steel is expected as candidate of structural piping material under high temperature condition in nuclear fusion instrument, and a tungsten inert gas (TIG) weld technique was applied for making its jointing. The defect size of 20mm was induced in the weld material. The guided wave, one of elastic waves, can propagate through very long pipe, and easily change to lots of modes by the defects in the structure. By analyzing the relationship between the mode conversion and the defects we can evaluate existing of the defects in weld material. In present study Nd-YAG laser was used to excite the guided wave by non-contact method, and AE technique was also used to clarify the mode conversion of guided wave by defect because lots of AE parameters of energy, count and amplitude can give more chances for analysis of mode conversion. The optimal AE parameters for the evaluation of the defects in weld zone using laser guided wave were derived.

Jin Kyung Lee; Dong Su Bae; Sang Pill Lee; Joon Hyun Lee

2014-01-01T23:59:59.000Z

342

Friction Stir Welding of Mild Steel -Tool Durability and Steel Microstructure , H. K. D. H. Bhadeshia2  

E-Print Network [OSTI]

1" " Friction Stir Welding of Mild Steel - Tool Durability and Steel Microstructure A. De1 , H. K of steel, and extend the calculations to cover consequences on the microstructure of the steel while and the consequences on the physical metallurgy of the steel. Introduction Friction stir welding (FSW) of aluminium

Cambridge, University of

343

Proceedings of NAMRI/SME, Vol. 39, 2011 Strength and Microstructure of Laser Fusion Welded Ti-SS  

E-Print Network [OSTI]

] or with the aid of a non-reactive interlayer [3][4]. Dissimilar metal welding (DMW) of the bio The ability to efficiently create robust and reliable dissimilar metal joints has the potential to enable new functionalities and reduce the manufacturing costs of medical devices. The need for dissimilar material welds

Yao, Y. Lawrence

344

Management Responsibilities  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Management Responsibilities Management Responsibilities Depleted UF6 Management Responsibilities DOE has responsibility for safe and efficient management of approximately 700,000 metric tons of depleted UF6. Organizational Responsibilities In the United States, the U.S. Department of Energy is responsible for managing all the depleted uranium that has been generated by the government and has been declared surplus to national defense needs. In addition, as a result of two memoranda of agreement that have been signed between the DOE and USEC, the DOE has assumed management responsibility for approximately 145,000 metric tons of depleted UF6 that has been or will be generated by USEC. Any additional depleted UF6 that USEC generates will be USEC's responsibility to manage. DOE Management Responsibility

345

Federal Energy Management Program: Energy Management Guidance  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Energy Management Energy Management Guidance to someone by E-mail Share Federal Energy Management Program: Energy Management Guidance on Facebook Tweet about Federal Energy Management Program: Energy Management Guidance on Twitter Bookmark Federal Energy Management Program: Energy Management Guidance on Google Bookmark Federal Energy Management Program: Energy Management Guidance on Delicious Rank Federal Energy Management Program: Energy Management Guidance on Digg Find More places to share Federal Energy Management Program: Energy Management Guidance on AddThis.com... Requirements by Subject Requirements by Regulation Notices & Rules Guidance Facility Reporting Fleet Reporting Energy Management Guidance The Federal Energy Management Program (FEMP) provides guidance on Federal

346

Environmental Management Waste Management Facility (EMWMF) at...  

Office of Environmental Management (EM)

Environmental Management Waste Management Facility (EMWMF) at Oak Ridge Environmental Management Waste Management Facility (EMWMF) at Oak Ridge Full Document and Summary Versions...

347

Friction Stir Welding of ODS Steels … Steps toward a Commercial Process  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Friction Stir Welding of ODS Friction Stir Welding of ODS Steels - Steps toward a Commercial Process 1 Glenn Grant Scott Weil Pacific Northwest National Laboratory Presented at the Workshop: Fe-Based ODS Alloys: Role and Future Applications University of California San Diego La Jolla, CA Nov 17 th - 18 th 2010 Barriers: * Traditionally produced by powder metallurgy methods that tend to be costly - Commercial viability requires new processing and manufacturing technology * Unfavorable anisotropic properties can result if processed improperly for the application * Cannot be welded by melt/solidification processes ODS Alloys: Incorporate a dispersion of nanoscale oxide particles (such as Y 2 O 3 ) in the ferritic matrix to mitigate grain boundary movement and allow greatly improved creep and high temperature strength while maintaining good

348

Morphologies of the transition region in dissimilar austenitic-ferritic welds  

SciTech Connect (OSTI)

The morphology of the transition region in dissimilar austenitic-ferritic steel welds has been characterized using scanning and transmission electron microscopy and using energy-dispersive X-ray spectrometry. With increasing base metal carbon content, a martensite-like layer in the unmixed zone of this region diminishes or disappears, and a saw-tooth-like morphology extends form the partially melted zone into the weld. The number of weld interfaces also changes with variation in carbon content, from the double austenite/martensite-like and martensite-like/ferrite interfaces to a single austenite/martensite-like one. These variations are attributed to the local melting range of the base metal, which depends upon the carbon content, cooling rate, and alloy element segregation.

Pan, C.; Zhang, Z. [Wuhan Transportation Univ., Wuhan, Hubei (China). Lab. of Electron Microscopy] [Wuhan Transportation Univ., Wuhan, Hubei (China). Lab. of Electron Microscopy

1996-01-01T23:59:59.000Z

349

High power x-ray welding of metal-matrix composites  

DOE Patents [OSTI]

A method for joining metal-matrix composites (MMCs) by using high power x-rays as a volumetric heat source is provided. The method involves directing an x-ray to the weld line between two adjacent MMCs materials to create an irradiated region or melt zone. The x-rays have a power density greater than about 10.sup.4 watts/cm.sup.2 and provide the volumetric heat required to join the MMC materials. Importantly, the reinforcing material of the metal-matrix composites remains uniformly distributed in the melt zone, and the strength of the MMCs are not diminished. In an alternate embodiment, high power x-rays are used to provide the volumetric heat required to weld metal elements, including metal elements comprised of metal alloys. In an alternate embodiment, high power x-rays are used to provide the volumetric heat required to weld metal elements, including metal elements comprised of metal alloys.

Rosenberg, Richard A. (Naperville, IL); Goeppner, George A. (Orland Park, IL); Noonan, John R. (Naperville, IL); Farrell, William J. (Flossmoor, IL); Ma, Qing (Westmont, IL)

1999-01-01T23:59:59.000Z

350

Using Phased Array Ultrasonic Testing in Lieu of Radiography for Acceptance of Carbon Steel Piping Welds  

SciTech Connect (OSTI)

The Pacific Northwest National Laboratory (PNNL) is conducting studies for the U.S. Nuclear Regulatory Commission (NRC) to assess the capability, effectiveness, and reliability of ultrasonic testing (UT) as a replacement method for radiographic testing (RT) for volumetric examination of nuclear power plant (NPP) components. This particular study focused on evaluating the use of UT on carbon steel plate welds. Welding fabrication flaws included a combination of planar and volumetric types, e.g., incomplete fusion, lack of penetration, cracks, porosity, and slag inclusions. The examinations were conducted using phased-array (PA) UT techniques applied primarily for detection and flaw type characterization. This paper will discuss the results of using UT in lieu of RT for detection and classification of fabrication flaws in carbon steel plate welds.

Moran, Traci L.; Anderson, Michael T.; Cinson, Anthony D.; Crawford, Susan L.; Nove, Carol A.

2014-08-01T23:59:59.000Z

351

Health Psychology Chapter Six: Stress  

E-Print Network [OSTI]

- individual X environment 2) Some Definitions: a) Generic- demands exceed capacity - engineering origins b stress responses, and (e) physical and mental health outcomes #12;Person-Environment Fit Sufficient by a nonspecific response. #12;What is Stress? Stress is a negative emotional experience accompanied

Meagher, Mary

352

Health Psychology Chapter Six: Stress  

E-Print Network [OSTI]

environment 2) Some Definitions: a) Generic- demands exceed capacity - engineering origins b) Biological stress responses, and (e) physical and mental health outcomes #12;Person-Environment Fit ! Sufficient by a nonspecific response. #12;What is Stress? ! Stress is a negative emotional experience accompanied

Meagher, Mary

353

Inertia-friction welding of particulate-reinforced aluminum matrix composites  

SciTech Connect (OSTI)

Aluminum metal-matrix composites (Al-MMC) are rapidly becoming materials of choice for many aerospace, automotive, recreational sports, and microelectronic applications. The attractive features of these materials include high specific strength and stiffness, a low coefficient of thermal expansion and enhanced wear characteristics relative to monolithic aluminum alloys. The effective engineering application of Al-MMC will commonly require their joining beth to themselves, to dissimilar Al-MMC, and to monolithic aluminum alloys. In the present work, dissimilar-alloy inertia-friction welds were produced between a 6061-T6 Al-MMC tube reinforced with l0 v/o Al{sub x}O{sub 3} particles (W6A.l0A-T6) and a modified A356 case MMC bar reinforced with 20 v/o SiC particles (F3S.20S), or a monolithic 6061-T6511 aluminum alloy bar. In Phase I, a fractional-factorial test matrix was statistically designed and performed to evaluate the effects of flywheel speed and axial pressure on the weld integrity, microstructure, hardness, tensile and torsion strengths and fracture behavior. In Phase 2, the effects of pre-weld machining of the solid bar on weld alignment and mechanical properties were evaluated. inertia-friction welding was shown to be effective for the joining of alumina particulate-reinforced composites to monolithic aluminum and to SiC-particulate reinforced aluminum. High-integrity joints exhibiting a defect-free joint interface with varying degrees of base alloy intermixing were produced at optimum parameter settings. Tensile and torsional strength joint efficiencies for the alumina-particulate MMC to monolithic aluminum alloy welds exceeded 80% and 75%, respectively, with tensile strength maximized with high axial pressure and flywheel speed, and torsional strength maximized at both medium and high levels of flywheel speed and axial pressure.

Cola, M.J.; Baeslack, W.A. III; Kou, M.

1994-12-31T23:59:59.000Z

354

Contact stress sensor  

DOE Patents [OSTI]

A method for producing a contact stress sensor that includes one or more MEMS fabricated sensor elements, where each sensor element of includes a thin non-recessed portion, a recessed portion and a pressure sensitive element adjacent to the recessed portion. An electric circuit is connected to the pressure sensitive element. The circuit includes a pressure signal circuit element configured to provide a signal upon movement of the pressure sensitive element.

Kotovsky, Jack

2014-02-11T23:59:59.000Z

355

Adaptation and risk management  

SciTech Connect (OSTI)

Adaptation assessment methods are compatible with the international risk management standard ISO:31000. Risk management approaches are increasingly being recommended for adaptation assessments at both national and local levels. Two orientations to assessments can commonly be identified: top-down and bottom-up, and prescriptive and diagnostic. Combinations of these orientations favor different types of assessments. The choice of orientation can be related to uncertainties in prediction and taking action, in the type of adaptation and in the degree of system stress. Adopting multiple viewpoints is to be encouraged, especially in complex situations. The bulk of current guidance material is consistent with top-down and predictive approaches, thus is most suitable for risk scoping and identification. Abroad range ofmaterial fromwithin and beyond the climate change literature can be used to select methods to be used in assessing and implementing adaptation. The framing of risk, correct formulation of the questions being investigated and assessment methodology are critical aspects of the scoping phase. Only when these issues have been addressed should be issue of specific methods and tools be addressed. The reorientation of adaptation from an assessment focused solely on anthropogenic climate change to broader issues of vulnerability/resilience, sustainable development and disaster risk, especially through a risk management framework, can draw from existing policy and management understanding in communities, professions and agencies, incorporating existing agendas, knowledge, risks, and issues they already face.

Preston, Benjamin L [ORNL

2011-01-01T23:59:59.000Z

356

In-situ repairs of pipelines using metal arc welding under oil (MAW-UO) aided by eddy current crack detection  

Science Journals Connector (OSTI)

Metal arc welding under oil (MAW-UO) is a new process developed to make in-situ internal repairs of in-service oil industry pipelines tanks and vessels without the need to evacuate the service from the containing fluid. High nickel alloy welding wires were used to produce a tough relatively soft austenitic weld metal; with reduced weld metal hardness porosity residual strain and cracking susceptibility. Eddy current sensors were able to detect cracks under oil which then can be repaired in-situ using MAW-UO. The in-situ under oil crack detection and arc weld repair process will be described.

2012-01-01T23:59:59.000Z

357

INVESTMENT MANAGEMENT OFFICE MANAGEMENT OFFICE  

E-Print Network [OSTI]

INVESTMENT MANAGEMENT OFFICE INVESTMENT MANAGEMENT OFFICE THE UNIVERSITY OF UTAH University of Utah | Investment Management Office Quarterly Summary The Endowment Pool had a positive first quarter (ending March gain from investments of $7.8 million. The Endowment Pool unit value of $100 has grown to $175 in 10

358

Laser-welded Interconnection of Screen-printed Si Solar Cells  

Science Journals Connector (OSTI)

Abstract We demonstrate the laser welding of Al interconnects to the BSF rear-side of screen-printed two-side-contacted solar cells. The Al paste on the rear side of solar cell is laser-welded to an Al foil. This reduces the silver consumption of the solar cells by making silver pads on the rear side obsolete. Our proof-of-concept modules are free of laser damage. A 3-cell-module from 6 solar cells shows no change in fill factor within the statistical measurement uncertainty after artificial aging in 500 humidity-freeze cycles.

Henning Schulte-Huxel; Susanne Blankemeyer; Verena Steckenreiter; Sarah Kajari-Schroeder; Rolf Brendel

2014-01-01T23:59:59.000Z

359

Diagenesis of the Terry sandstone member of the Pierre Shale, Spindle field, Weld County, Colorado  

E-Print Network [OSTI]

DIAGENESIS OF THE TERRY SANDSTONE MEMBER OF THE PIERRE SHALE, SPINDLE FIELD, WELD COUNTY, COLORADO A Thesis PHILLIP DEAN HAYS Submitted to the Gradute College of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1986 Major Subject: Geology DIAGNESIS OF THE TERRY SANDSTONE MEMBER OF THE PIERRE SHALE ~ SP INDLE F I ELD ~ WELD COUNTY ~ COLORADO A Thesis by PHILLIP DEAN HAYS Approved as to style and content by: -, ~jD Thomas T...

Hays, Phillip Dean

1986-01-01T23:59:59.000Z

360

Fully-automatic laser welding and micro-sculpting with universal in situ inline coherent imaging  

E-Print Network [OSTI]

Though new affordable high power laser technologies make possible many processing applications in science and industry, depth control remains a serious technical challenge. Here we show that inline coherent imaging, with line rates up to 312 kHz and microsecond-duration capture times, is capable of directly measuring laser penetration depth in a process as violent as kW-class keyhole welding. We exploit ICI's high speed, high dynamic range and robustness to interference from other optical sources to achieve fully automatic, adaptive control of laser welding as well as ablation, achieving micron-scale sculpting in vastly different heterogeneous biological materials.

Webster, Paul J L; Ji, Yang; Galbraith, Christopher M; Kinross, Alison W; Van Vlack, Cole; Fraser, James M

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Yucca Mountain Waste Package Closure System Robotic Welding and Inspection System  

SciTech Connect (OSTI)

The Waste Package Closure System (WPCS), for the closure of radioactive waste in canisters for permanent storage of spent nuclear fuel (SNF) and high-level waste in the Yucca Mountain Repository was designed, fabricated, and successfully demonstrated at the Idaho National Laboratory (INL). This article focuses on the robotic hardware and tools necessary to remotely weld and inspect the closure lid welds. The system was operated remotely and designed for use in a radiation field, due to the SNF contained in the waste packages being closed.

C. I. Nichol; D. P. Pace; E. D. Larsen; T. R. McJunkin; D. E. Clark; M. L. Clark; K. L. Skinner; A. D. Watkins; H. B. Smartt

2011-10-01T23:59:59.000Z

362

Federal Energy Management Program: Computerized Maintenance Management  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Computerized Computerized Maintenance Management Systems to someone by E-mail Share Federal Energy Management Program: Computerized Maintenance Management Systems on Facebook Tweet about Federal Energy Management Program: Computerized Maintenance Management Systems on Twitter Bookmark Federal Energy Management Program: Computerized Maintenance Management Systems on Google Bookmark Federal Energy Management Program: Computerized Maintenance Management Systems on Delicious Rank Federal Energy Management Program: Computerized Maintenance Management Systems on Digg Find More places to share Federal Energy Management Program: Computerized Maintenance Management Systems on AddThis.com... Sustainable Buildings & Campuses Operations & Maintenance Federal Requirements Program Management

363

LRRB Pavement Management Systems Pavement Management Systems  

E-Print Network [OSTI]

LRRB Pavement Management Systems Pavement Management Systems Presented by: Michael Marti SRF for implementing and monitoring research results (RIC) #12;LRRB Pavement Management Systems LRRB Structure LRRB Current Pavement Management System Used ICON (Goodpointe) Year of Pavement Management System

Minnesota, University of

364

SUBCONTRACT MANAGEMENT  

Broader source: Energy.gov (indexed) [DOE]

-1 -1 CHAPTER 10 SUBCONTRACT MANAGEMENT (Revised October 19, 2011) WHAT ARE THE BASIC PRINCIPLES AND OBJECTIVES OF SUBCONTRACT MANAGEMENT? 1. To ensure contractors establish, document, and maintain adequate purchasing systems. 2. To ensure contractors flow down contract requirements to subcontractors. WHY IS SUBCONTRACT MANAGEMENT IMPORTANT? In many Department prime contracts a significant portion of the obligated dollars is spent on subcontract work. Due to the absence of a direct contractual relationship with the subcontractor, the Department must rely on the prime contractor to manage subcontract work. Subcontractors perform significant work efforts at sites and are an integral part of the site's success. Prime

365

Program Manager  

Broader source: Energy.gov [DOE]

A successful candidate in this position will participate in a wide spectrum of program and project management activities involving systems engineering and integration support for Defense Programs...

366

Water Management  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Water Management This department applies multi-disciplinary science and technology-based modeling to assess complex environmental systems. It integrates ecology, anthropology, and...

367

Position Management  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

The order prescribes the policies, responsibilities, and procedures for position management within (DOE). Canceled by DOE N 1321.140. Cancels DOE 3510.1

1992-06-23T23:59:59.000Z

368

MANAGEMENT (MNG)  

Broader source: Energy.gov (indexed) [DOE]

and recommendations is adequately implemented. (DOE Order 414.1A, Criterion 3; 10 CFR 830, Subpart A) Approach Record Review * Review the SWS issues management systems and...

369

Modifications in the AA5083 Johnson-Cook Material Model for Use in Friction Stir Welding  

E-Print Network [OSTI]

Modifications in the AA5083 Johnson-Cook Material Model for Use in Friction Stir Welding- turing processes involving plastic deformation of metallic materials. The main attraction to this model (e.g., those associated with the influence of plastic deformation, rate of deformation

Grujicic, Mica

370

Laser-ultrasonic inspection of hybrid laser-arc welded HSLA-65 steel  

SciTech Connect (OSTI)

The hybrid laser-arc welding (HLAW) process is a relatively low heat input joining technology that combines the synergistic qualities of both the high energy density laser beam for deep penetration and the arc for wide fit-up gap tolerance. This process is especially suitable for the shipbuilding industry where thick-gauge section, long steel plates have been widely used in a butt joint configuration. In this study, preliminary exploration was carried out to detect and visualize the welding defects using laser ultrasonics combined with the synthetic aperture focusing technique (SAFT). Results obtained on 9.3 mm thick butt-welded HSLA-65 steel plates indicated that the laser-ultrasonic SAFT inspection technique can successfully detect and visualize the presence of porosity, lack of fusion and internal crack defects. This was further confirmed by X-ray digital radiography and metallography. The results obtained clearly show the potential of using the laser-ultrasonic technology for the automated inspection of hybrid laser-arc welds.

Lvesque, D.; Rousseau, G.; Monchalin, J.-P. [National Research Council Canada, Boucherville, QC (Canada); Wanjara, P.; Cao, X. [National Research Council Canada, Montreal, QC (Canada)

2014-02-18T23:59:59.000Z

371

Characteristics of High-Power Diode-Laser Welds for Industrial Assembly C.A. Walsh*  

E-Print Network [OSTI]

rate and nozzle angle (with workpiece) on welding speed and penetration. They found flow rate. An optimum flow rate existed at which the penetration depth was maximised (2.3 mm with a 2 k that the penetration depth tended to increase slightly with increasing nozzle angle and was also sensitive to the gas

Cambridge, University of

372

Ion-irradiation-induced welding of carbon nanotubes A. V. Krasheninnikov, K. Nordlund, and J. Keinonen  

E-Print Network [OSTI]

been suggested16 to use a low-energy 3 eV bombardment of crossed nanotubes with carbon ions to formIon-irradiation-induced welding of carbon nanotubes A. V. Krasheninnikov, K. Nordlund, and J, electron irradiation can be used to create molecular junctions between carbon nanotubes. Employing

Krasheninnikov, Arkady V.

373

F i W ldiFusion Welding ME 4210: Manufacturing Processes and Engineering  

E-Print Network [OSTI]

-fuel) cutting · Thermit Electric arc· Electric arc · Resistance L b· Laser beam · Electron beam ME 4210 Welding ME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2009 11 #12;Electric ArcElectric solid rocket booster (SRB) · In skin of Hindenburg dirigible ­ electrostatic discharge caused fire ME

Colton, Jonathan S.

374

Carbon migration in 5Cr-0.5Mo/21Cr-12Ni dissimilar metal welds  

SciTech Connect (OSTI)

The carbon migration between a ferritic steel and an austenitic steel was studied in submerged arc-welded 5Cr-0.5Mo/21Cr-12Ni dissimilar metal welds (DMWs) after aging at 500 C for various times and after long-term service in technical practice. The distribution of carbon, chromium, nickel, and iron in the areas around the weld interface was determined by electron probe microanalysis, and the microstructural aspect in the carbon-depleted/enriched zone was characterized by optical microscopy and transmission electron microscopy (TEM). Furthermore, the precipitation sequences and composition characteristics of the carbides were identified by diffraction pattern microanalysis and energy-dispersive X-ray (EDX) microanalysis. It was found (1) that there exists a coherent relationship between intracrystalline M{sub 23}C{sub 6} and the austenitic matrix; (2) that the composition of M{sub 23}C{sub 6} in the carbon-enriched zone is independent of the duration of aging and service; (3) that the maximum carbon concentration is determined by the carbide type, the composition characteristic of precipitated carbides, and the concentration of carbide-forming Cr adjacent to the weld interface in the carbon-enriched zone; and (4) that the carbon migration in the 5Cr-0.5Mo/21Cr-12Ni DMWs can be described by a diffusion model.

Huang, M.L.; Wang, L. [Dalian Univ. of Technology (China). Dept. of Materials Engineering

1998-12-01T23:59:59.000Z

375

Environmental concerns are driving the development of the welding processes and applications  

E-Print Network [OSTI]

in the energy sector. Installation of wind power stations is rapidly growing 30-50 % per year. Safe storage are fairly slow in implementing environmental programmes in the welding industries we have major challenges described applications from the shipyard, wind and nuclear power and automotive industries will illustrate

Cambridge, University of

376

Friction Stir Lap Welding of Magnesium Alloy to Steel: A Preliminary Investigation  

SciTech Connect (OSTI)

An initial study was made to evaluate the feasibility of joining Magnesium alloy AZ31 sheet to galvanized steel sheet in lap configuration using friction stir welding (FSW). Two different automotive sheet steels were used for comparative evaluation of the dissimilar joining potential; a 0.8mm thick, electro galvanized (EG) mild steel, and a 1.5mm thick hot dipped galvanized (HDG) high-strength, low-alloy steel (HSLA). These steels were joined to 2.33mm thick AZ31B magnesium sheet. A single FSW tool design was used for both dissimilar welds, and process parameters were kept the same. Average peak load for the AZ31-1.5 mm steel weld joint in lap shear mode was found to be 6.3 1.0 kN. For the AZ31-0.8 mm steel weld, joint strength was 5.1 1.5 kN. Microstructural investigation indicates melting of the Zn coating at the interface and subsequent alloying with the Mg sheet resulting in formation of solidified Zn-Mg alloy layer at AZ31/steel interface.

Jana, Saumyadeep; Hovanski, Yuri; Grant, Glenn J.

2010-12-01T23:59:59.000Z

377

Optimized Sampling Frequencies for Weld Reliability Assessments of Long Pipeline Segments  

E-Print Network [OSTI]

. To be on the safe side, regulations require that a pipeline be repaired when it is possible that p ?? p 0 , i.e., when p ?? p 0 . Need for Optimal Resource Allocation for Pipeline As­ sessment: Pipeline repairsOptimized Sampling Frequencies for Weld Reliability Assessments of Long Pipeline Segments Cesar J

Kreinovich, Vladik

378

Optimized Sampling Frequencies for Weld Reliability Assessments of Long Pipeline Segments  

E-Print Network [OSTI]

. To be on the safe side, regulations require that a pipeline be repaired when it is possible that p p0, i.e., when p p0. Need for Optimal Resource Allocation for Pipeline As- sessment: Pipeline repairs are extremelyOptimized Sampling Frequencies for Weld Reliability Assessments of Long Pipeline Segments Cesar J

Kreinovich, Vladik

379

Method and design for externally applied laser welding of internal connections in a high power electrochemical cell  

DOE Patents [OSTI]

An electrochemical cell includes components that are welded from an external source after the components are assembled in a cell canister. The cell canister houses electrode tabs and a core insert. An end cap insert is disposed opposite the core insert. An external weld source, such as a laser beam, is applied to the end cap insert, such that the end cap insert, the electrode tabs, and the core insert are electrically coupled by a weld which extends from the end cap insert to the core insert.

Martin, Charles E; Fontaine, Lucien; Gardner, William H

2014-01-21T23:59:59.000Z

380

Estimate of the allowable dimensions of diagnosed defects in category III and IV welded pipeline joints{sup 1}  

SciTech Connect (OSTI)

An approach for estimating the permissible dimensions of technological defects in butt welded joints in category III and IV pipelines is described. The allowable size of a welding defect is determined from the condition of compliance with the specifications on strength for a reference cross section (damaged joint) of the pipeline taking into account its weakening by a given defect.With regard to the fairly widespread discovery of technological defects in butt welded joints during diagnostics of auxiliary pipelines for thermal electric power plants, the proposed approach can be used in practice by repair and consulting organizations.

Grin', E. A.; Bochkarev, V. I. [JSC 'All-Russia Thermal Engineering Institute' (JSC 'VTI') (Russian Federation)] [JSC 'All-Russia Thermal Engineering Institute' (JSC 'VTI') (Russian Federation)

2013-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

A luminescent nanocrystal stress gauge  

SciTech Connect (OSTI)

Microscale mechanical forces can determine important outcomes ranging from the site of material fracture to stem cell fate. However, local stresses in a vast majority of systems cannot be measured due to the limitations of current techniques. In this work, we present the design and implementation of the CdSe/CdS core/shell tetrapod nanocrystal, a local stress sensor with bright luminescence readout. We calibrate the tetrapod luminescence response to stress, and use the luminescence signal to report the spatial distribution of local stresses in single polyester fibers under uniaxial strain. The bright stress-dependent emission of the tetrapod, its nanoscale size, and its colloidal nature provide a unique tool that may be incorporated into a variety of micromechanical systems including materials and biological samples to quantify local stresses with high spatial resolution.

Choi, Charina; Koski, Kristie; Olson, Andrew; Alivisatos, Paul

2010-10-25T23:59:59.000Z

382

Effect of activity differences on hydrogen migration in dissimilar titanium alloy welds  

SciTech Connect (OSTI)

The effect of alloy composition on hydrogen activity was measured for seven titanium alloys as a means to determine the tendency for hydrogen migration within dissimilar metal welds. The alloys were: Ti-CP (unalloyed Ti), Ti-3Al-2.5V, Ti-3Al-2.5V-3Zr, Ti-3Al-2Nb-1Ta, Ti-6Al, Ti-6Al-4V, and Ti-6Al-2Nb-1Ta-0.8Mo. Hydrogen pressure-hydrogen concentration relationships were determined for temperatures from 600 C to 800 C and hydrogen concentrations up to approximately 3.5 at. pct (750 wppm). Fusion welds were made between Ti-CP and Ti-CP and between Ti-CP and Ti-6Al-4V to observe directly the hydrogen redistribution in similar and dissimilar metal couples. Hydrogen activity was found to be significantly affected by alloying elements, particularly Al in solid solution. At a constant Al content and temperature, an increase in the volume fraction of {beta} reduced the activity of hydrogen in {alpha}-{beta} alloys. Activity was also found to be strongly affected by temperature. The effect of temperature differences on hydrogen activity was much greater than the effects resulting from alloy composition differences at a given temperature. Thus, hydrogen redistribution should be expected within similar metal couples subjected to extreme temperature gradients, such as those peculiar to fusion welding. Significant hydrogen redistribution in dissimilar alloy weldments also can be expected for many of the compositions in this study. Hydride formation stemming from these driving forces was observed in the dissimilar couple fusion welds. In addition, a basis for estimating hydrogen migration in titanium welds, based on hydrogen activity data, is described.

Kennedy, J.R.; Adler, P.N. [Grumman Corp., Bethpage, NY (United States). Corporate Research Center; Margolin, H. [Polytechnic Univ., Brooklyn, NY (United States). Dept. of Materials Science and Engineering

1993-12-01T23:59:59.000Z

383

In mold laser welding for high precision polymer based optical components  

SciTech Connect (OSTI)

To assemble a complete subsystem as a rear lamp, is necessary to have different machines and to perform several tasks. This necessity obliges the companies to have large structures to support all the assembling process. These huge structures are very costly and have as a consequence the reduction of the competitiveness of the companies. The process presented in this document has the intention of reducing the number of tasks needed to produce the final subsystem/product. To achieve this goal were combined several technologies, as in-mould assembling, laser welding and LEDs (light-emitting diode). One of the advantages of this process was the utilization of only one injection molding machine with three injection units to do all the assembling process. To achieve the main objective, firstly, the rear lamp was designed according to with the legislation of UNECE Vehicle Regulations - 1958 Agreements; Regulation No. 50 -Rev.2 - Position lamps, stop lamps, direction indicators for motorcycles. Posterior several polymeric materials were studied at different levels. Initial were studied several concentrations of carbon nanotubes mixed with PC (polycarbonate). This had the objective of determine, if these materials are suitable to conduct the necessary electric current to turn on the different LEDs. One of the main advantages of this process is the use of the laser transmission welded process. Since, with this welding technology is possible reduce the complexity of the final part. To understand the potentialities of this technology a combination of two materials was studied. The studied showed that all materials presented a high transparency to the laser beam. In terms of weld process, the study showed that the best welding conditions are the lowest velocity, diameter and power. With these studies was possible conclude that this new process is suitable to be implemented at the industrial level.

Oliveira, N., E-mail: id2694@alunos.uminho.pt, E-mail: pontes@dep.uminho.pt; Pontes, A. J., E-mail: id2694@alunos.uminho.pt, E-mail: pontes@dep.uminho.pt [IPC - Institute for Polymers and Composites, Department of Polymer Engineering, University of Minho, 4800-058 Guimares (Portugal)

2014-05-15T23:59:59.000Z

384

Microstructural development in PWA-1480 electron beam welds: An atom probe field ion microscopy study  

SciTech Connect (OSTI)

The microstructure development in PWA-1480 superalloy electron beam weld (Ni-11.0 at. % Al-11.5% Cr-1.9% Ti-5.1% Co-4.0% Ta-1.3% W) was characterized. Optical microscopy revealed a branched dendritic structure in the weld metal. Transmission electron microscopy of these welds, in the as-welded condition, showed fine cuboidal (0.05--0.5 {mu}m) L1{sub 2}-ordered {gamma}{prime} precipitates within the y grains. The average volume percentage of {gamma}{prime} precipitates was found to be {approx}5%. Atom probe analyses revealed that the composition of {gamma} matrix was Ni-4.6 at. % Al-25.5% Cr-0.4% Ti-9.4% Co-0.8% Ta-2.9% W and that of {gamma}{prime} precipitates was Ni-17.3 at. % Al-2.6% Cr-2.4% Ti-3.0% Co-7.4% Ta-1.3% W. These compositions were compared with the previous APFIM analyses of commercial PWA-1480 single crystals that had received conventional heat treatments. Small differences were found in the chromium and aluminum levels and these may be due to the nonequilibrium nature of phase transformations that occur during weld cooling. No solute segregation was detected at the {gamma}-{gamma}{prime}interface. The APFIM results were also compared with the thermodynamic calculations of alloying element partitioning between {gamma} and {gamma}{prime} using the ThermoCalc{trademark} software.

David, S.A.; Miller, M.K. [Oak Ridge National Lab., TN (United States); Babu, S.S. [The Pennsylvania State Univ., State College, PA (United States)

1995-12-31T23:59:59.000Z

385

DEACTIVATION MANAGEMENT  

Broader source: Energy.gov (indexed) [DOE]

MANAGEMENT MANAGEMENT The purpose here is to provide information for specific aspects of project management that apply to deactivation. Overall management of deactivation projects should use a traditional project management approach, and as such is not addressed. The following specific topics are based on lessons learned during deactivation of DOE facilities.  The Deactivation Mission  The Stabilization/Deactivation "Customer"  Project Approach for a Complex Facility  Establishing the Overall End-State  Viewing Deactivation in Two Phases  Early Decisions  Early Deactivation Tasks  Facility-Specific Commitments  Hazard Reduction  Detailed End-Points  Set Up Method and Criteria  Post-Deactivation S&M Plan

386

BachelorofManagement InternationalManagement  

E-Print Network [OSTI]

on the official transcript (see Part 11 - Faculty of Management in the 2007/2008 Calendar). Program Planning Guide Management 3050/Political Science 3420 - Human Resource Management Management 3061 - Information Systems Environment Management 3640 - Cross-Cultural Management Practices Management 3660/Geography 3225 - Industrial

Seldin, Jonathan P.

387

Characterizations of 21-4N to 4Cr9Si2 stainless steel dissimilar joint bonded by electric-resistance-heat-aided friction welding  

Science Journals Connector (OSTI)

A new welding process, electric-resistance-heat-aided friction welding (ERHAFW), was introduced in this study. To further improve the joint quality and energy-saving, electric resistance welding was combined with the conventional continuous-drive friction welding. 21-4N (austenitic stainless steel) and 4Cr9Si2 (martensitic stainless steel) valve steel rods of 4mm diameter were used as base metals. The results show that electric-resistance-heat-aided friction welding can be applied to join thin rods within a relatively short time, which is very difficult for conventional friction welding (FW). The microstructure of ERHAFW bonded 21-4N to 4Cr9Si2 presents non-uniform across the joint. Different structure zones are observed from the weld line to both sides, which are the weld center, thermo-mechanically affected zone (TMAZ) and heat affected zone (HAZ). These regions exhibit different structures owing to the difference in the thermophysical and mechanical properties of these two steels under the fast heating and cooling during welding. The variation of microhardness in the joint is attributed to the microstructure change. The higher microhardness is obtained in the weld center and TMAZ of 4Cr9Si2 corresponding to the presence of fine tempered martensite and carbides.

Wen-Ya Li; Min Yu; Jinglong Li; Guifeng Zhang; Shiyuan Wang

2009-01-01T23:59:59.000Z

388

Technical Letter Report Assessment of Ultrasonic Phased Array Testing for Cast Austenitic Stainless Steel Pressurizer Surge Line Piping Welds and Thick Section Primary System Cast Piping Welds JCN N6398, Task 2A  

SciTech Connect (OSTI)

Research is being conducted for the NRC at PNNL to assess the effectiveness and reliability of advanced NDE methods for the inspection of LWR components. The scope of this research encompasses primary system pressure boundary materials including cast austenitic stainless steels (CASS), dissimilar metal welds (DMWs), piping with corrosion-resistant cladding, weld overlays, and far-side examinations of austenitic piping welds. A primary objective of this work is to evaluate various NDE methods to assess their ability to detect, localize, and size cracks in coarse-grained steel components. This interim technical letter report (TLR) provides a synopsis of recent investigations at PNNL aimed at evaluating the capabilities of phased-array (PA) ultrasonic testing (UT) methods as applied to the inspection of CASS welds in nuclear reactor piping. A description of progress, recent developments and interim results are provided.

Diaz, Aaron A.; Denslow, Kayte M.; Cinson, Anthony D.; Morra, Marino; Crawford, Susan L.; Prowant, Matthew S.; Cumblidge, Stephen E.; Anderson, Michael T.

2008-07-21T23:59:59.000Z

389

Welding Cutting and Brazing Assessment Plan Assessment plan - Developed By NNSA/Nevada Site Office Facility Representative Division  

Broader source: Energy.gov (indexed) [DOE]

WELDING, CUTTING AND BRAZING WELDING, CUTTING AND BRAZING Assessment Plan NNSA/Nevada Site Office Facility Representative Division Performance Objective: This assessment is to verify hot work requirements associated with welding, cutting, burning, brazing, grinding and other spark- or flame-producing operations have been implemented. Verify that the requirements implemented are appropriate for preventing loss of life and property from fire, and personal injury from contact with or exposure to molten metals, vapors, radiant energy, injurious rays and sparks. Criteria: Establish designated area in which routine and repetitive welding, cutting, and other spark- or flame producing operations are conducted [1910.252(a)(2)(iv),1910.252(a)(2)(vi)(A), 1910.252(a)(2)(xv), General Requirements].

390

Effect of pressure and shielding gas on the microstructure of hyperbaric metal cored GMAW welds down to 111 bar  

SciTech Connect (OSTI)

The microstructural evolution of hyperbaric C-Mn weld metals was studied by means of bead-on-plate welds deposit with GMAW process using a commercial metal cored wire. The welding was carried out in the flat position in the range of 51 bar to 111 bar with He+ CO{sub 2} as shielding gas, which CO{sub 2} content varied from 0.1% to 0.8 %. The microstructures were quantitatively analyzed by optical microscopy to evaluate the amount of constituents according to the IIW/IIS terminology. The results showed that all weld metals presented great amounts of acicular ferrite and a stronger influence of pressure on microstructure compared to the influence of the shielding gas.

Jorge, J.C.F. [CEFET, Rio de Janeiro (Brazil). Mechanical Engineering Dept.; Santos, V.R. dos [Petrobras/CENPES, Rio de Janeiro (Brazil); Santos, J.F. dos [GKSS Forschungszentrum Geesthacht GmbH (Germany)

1995-12-31T23:59:59.000Z

391

Materials Reliability Program Low-Temperature Cracking of Nickel-Based Alloys and Weld Metals (MRP-108)  

SciTech Connect (OSTI)

OAK-B135 A rising load test in low-temperature (50-100 degree C) pH 10 water containing a high concentration of dissolved hydrogen (150 cc/kg) has demonstrated that Alloy 690 as well as weld metals 82 and 52 exhibit a marked loss of ductility. A similar loss of ductility has been shown to occur in widely used weld metal 182 under replica test conditions and simulated PWR primary water containing 100 cc/kg of hydrogen. The objective of this report was to confirm the Bettis test results for weld metal 82 and determine whether weld metal 182 is susceptible to the same reductions in toughness. This report documents the first industry effort to reckon with the low temperature crack propagation (LTCP) issue.

B. Young

2004-02-01T23:59:59.000Z

392

Formation mechanism of linear friction welded Ti-6Al-4V alloy joint based on microstructure observation  

SciTech Connect (OSTI)

The microstructure of the linear friction welded Ti-6Al-4V titanium alloy joint was investigated by optical microscope, scanning electronic microscope and transmission electron microscope. Results show that the dynamic recovery and recrystallization resulting from the intensive plastic deformation and fast heating and cooling processes during linear friction welding account for the superfine {alpha} + {beta} grains in the weld center. Fine {alpha} grains distribute in the {beta} matrix or at the boundaries of {beta} grains. A mass of dislocations networks and metastructures present within the {alpha} and {beta} grains. - Research Highlights: {yields} TEM is employed in the analysis. {yields} The dynamic recovery is the main mechanism in thermal deformation of TC4. {yields} Superfine grains in the weld result from dynamic recovery and dynamic recrystallizaion, but the recrystallization is inadequate.

Ma Tiejun; Chen Tao, E-mail: ctwc-13@163.com; Li Wenya; Wang Shiwei; Yang Siqian

2011-01-15T23:59:59.000Z

393

Management Overview  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Immobilization Research Immobilization Research Kurt Gerdes U.S. DOE, Office of Engineering and Technology John Vienna Pacific Northwest National Laboratory Environmental Management May 19, 2009 2009 Hanford - Idaho - Savannah River Technical Exchange 2 Objectives Perform research and development to advance the waste stabilization technology options by through closely- coupled theory, experimentation, and modeling Develop solutions for Hanford, Idaho, Savannah River, and Oak Ridge wastes challenges (along with facilitating management of future wastes) Environmental Management General Approach Balance between near-term incremental technology improvements and long-term transformational solutions Address the requirements for high risk waste streams - high-level tank waste (RPP, SRS)

394

Summary of Dissimilar Metal Joining Trials Conducted by Edison Welding Institute  

SciTech Connect (OSTI)

Under the direction of the NASA-Glenn Research Center, the Edison Welding Institute (EWI) in Columbus, OH performed a series of non-fusion joining experiments to determine the feasibility of joining refractory metals or refractory metal alloys to Ni-based superalloys. Results, as reported by EWI, can be found in the project report for EWI Project 48819GTH (Attachment A, at the end of this document), dated October 10, 2005. The three joining methods used in this investigation were inertia welding, magnetic pulse welding, and electro-spark deposition joining. Five materials were used in these experiments: Mo-47Re, T-111, Hastelloy X, Mar M-247 (coarse-grained, 0.5 mm to several millimeter average grain size), and Mar M-247 (fine-grained, approximately 50 {micro}m average grain size). Several iterative trials of each material combination with each joining method were performed to determine the best practice joining method. Mo-47Re was found to be joined easily to Hastelloy X via inertia welding, but inertia welding of the Mo-alloy to both Mar M-247 alloys resulted in inconsistent joint strength and large reaction layers between the two metals. T-111 was found to join well to Hastelloy X and coarse-grained Mar M-247 via inertia welding, but joining to fine-grained Mar M-247 resulted in low joint strength. Magnetic pulse welding (MPW) was only successful in joining T-111 tubing to Hastelloy X bar stock. The joint integrity and reaction layer between the metals were found to be acceptable. This single joining trial, however, caused damage to the electromagnetic concentrators used in this process. Subsequent design efforts to eliminate the problem resulted in a loss of power imparted to the accelerating work piece, and results could not be reproduced. Welding trials of Mar M-247 to T-111 resulted in catastrophic failure of the bar stock, even at lower power. Electro-spark deposition joining of Mo-47Re, in which the deposited material was Hastelloy X, did not have a noticeable reaction layer. T-111 was found to have a small reaction layer at the interface with deposited Hastelloy X. Mar M-247 had a reaction layer larger than T-111. Hastelloy X joined well with a substrate of the same alloy, and throughout the experiments was found to have a density of {approx}99%, based on metallographic observations of porosity in the deposit. Of the three joining methods tested, inertial welding of bar stock appears to be the most mature at this time. MPW may be an attractive alternative due to the potential for high bond integrity, similar to that seen in explosion bonding. However, all three joining methods used in this work will require adaptation in order to join piping and tubing. Further investigations into the change in mechanical properties of these joints with time, temperature, irradiation, and the use of interlayers between the two materials must also be performed.

MJ Lambert

2005-11-18T23:59:59.000Z

395

Holographic in situ stress measurements  

Science Journals Connector (OSTI)

......Stress-relief data have been obtained from our initial field deployment of the stressmeter in a horizontal borehole in an oil shale mine. These data establish the viability of holographic interferometry for deducing the level of in situ stress in boreholes......

Jay D. Bass; Douglas Schmitt; Thomas J. Ahrens

1986-04-01T23:59:59.000Z

396

Post-Traumatic Stress Disorder  

E-Print Network [OSTI]

Post-Traumatic Stress Disorder (PTSD) National Institute of Mental Health U.S. Department of HealtH anD HUman ServiceS · national institutes of Health #12;Contents What is post traumatic stress disorder after seeing or living through a dangerous event. When in danger, it's natural to feel afraid. This fear

Bandettini, Peter A.

397

ALLIANCE MANAGEMENT  

Science Journals Connector (OSTI)

In the last two decades, production and manufacturing management has rapidly adopted a range of new concepts: manufacturing strategy, focused factory, just-in-time manufacturing, concurrent engineering, total ...

2000-01-01T23:59:59.000Z

398

Deformation behavior of laser welds in high temperature oxidation resistant FeCrAl alloys for fuel cladding applications  

Science Journals Connector (OSTI)

Abstract Ferritic-structured FeCrAl alloys are being developed and show promise as oxidation resistant accident tolerant light water reactor fuel cladding. This study focuses on investigating the weldability and post-weld mechanical behavior of three model alloys in a range of Fe(1317.5)Cr(34.4)Al (wt.%) with a minor addition of yttrium using modern laser-welding techniques. A detailed study on the mechanical performance of bead-on-plate welds using sub-sized, flat dog-bone tensile specimens and digital image correlation (DIC) has been carried out to determine the performance of welds as a function of alloy composition. Results indicated a reduction in the yield strength within the fusion zone compared to the base metal. Yield strength reduction was found to be primarily constrained to the fusion zone due to grain coarsening with a less severe reduction in the heat affected zone. For all proposed alloys, laser welding resulted in a defect free weld devoid of cracking or inclusions.

Kevin G. Field; Maxim N. Gussev; Yukinori Yamamoto; Lance L. Snead

2014-01-01T23:59:59.000Z

399

Analysis of dissimilar welds exposed to high temperature H{sub 2}/H{sub 2}S conditions in a hydrodesulfurizing (HDS) unit  

SciTech Connect (OSTI)

In high temperature applications, dissimilar welds made with nickel-base alloy filler metals provide extended service lives as compared to similar welds made with stainless steel filler metals. Although considerable refinery experience exists, it is difficult to find published information for pressure boundary welds made with nickel-base filler metal in hot hydrogen and/or H{sub 2}S services. The Amuay Refinery has used nickel base alloy filler metals to join clad piping components in a number of piping applications. This paper details the results of an analysis of clad 1{1/4}Cr-{1/2} Mo steel hydroprocessing reactor effluent piping samples removed from service to assess the long term effects of hydrogen and H{sub 2}S on the dissimilar weld. Results of mechanical testing and metallurgical analysis reveal that no significant loss in properties occurred. Details of the weld procedures and weld joint design are provided.

Penuela, L.E.; Chirinos, J.G. [PDVSA Manufacture y Mercado, Judibana (Venezuela). Centro Refinacion Paraguana; Dobis, J.D. [KLAD Inc., Elkton, MD (United States)

1999-11-01T23:59:59.000Z

400

Stormwater Management  

E-Print Network [OSTI]

management program must be developed that would meet the standard of reducing pollutants to the maximum extent practicable. Stormwater management programs for medium and large MS4s include measures to: ? Identify major outfalls and pollutant loadings... seeding: The vegetation used will be part of final landscaping, but during construction it prevents soil erosion. ? Mulching: Materials such as hay, grass, woodchips, gravel, or straw are placed on top of the soil to keep it from eroding. Structural...

Jaber, Fouad

2008-10-23T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Materials Reliability Program Resistance to Primary Water Stress Corrosion Cracking of Alloys 690, 52, and 152 in Pressurized Water Reactors (MRP-111)  

SciTech Connect (OSTI)

Over the last thirty years, stress corrosion cracking in PWR primary water (PWSCC) has been observed in numerous Alloy 600 component items and associated welds, sometimes after relatively long incubation times. Repairs and replacements have generally utilized wrought Alloy 690 material and its compatible weld metals (Alloy 152 and Alloy 52), which have been shown to be very highly resistant to PWSCC in laboratory experiments and have been free from cracking in operating reactors over periods already up to nearly 15 years. It is nevertheless prudent for the PWR industry to attempt to quantify the longevity of these materials with respect to aging degradation by corrosion in order to provide a sound technical basis for the development of future inspection requirements for repaired or replaced component items. This document first reviews numerous laboratory tests, conducted over the last two decades, that were performed with wrought Alloy 690 and Alloy 52 or Alloy 152 weld materials under various test conditions pertinent to corrosion resistance in PWR environments. The main focus of the present review is on PWSCC, but secondary-side conditions are also briefly considered.

H.Xu, S.Fyfitch, P.Scott, M.Foucault, R.Kilian, and M.Winters

2004-03-01T23:59:59.000Z

402

RECORD OF CATEGORICAL EXCLUSION DETERMINATION Ault Substation Expansion and Equipment Additions, Weld County, CO  

Broader source: Energy.gov (indexed) [DOE]

Ault Substation Expansion and Equipment Additions, Weld County, CO Ault Substation Expansion and Equipment Additions, Weld County, CO A. Proposed Action: Western proposes to expand the existing Ault SUbstation and add electrical equipment. The expansion would be within the existing fee-owned land. B. Number and Title of Categorical Excluison Being Applied . B4.11: Construction of electric power substations (including switching stations and support facilities) with power deliver at 230-kV or below, or modification (other than voltage increases) of existing sutstations and support facilities .. .. C. Regulatory Requirements in 10 CFR 1021.410(b): (Refer to full text in regulation ). (1) The proposed action fits within a class of actions that is listed in Appendix A or B to Subpart D. For classes of actions, listed in Appendix B, the following conditions are

403

Determination of mechanical and fracture properties of laser beam welded steel joints  

SciTech Connect (OSTI)

In the present work, two similar joints, namely, ferritic-ferritic and austenitic-austenitic and one dissimilar ferritic-austenitic joint were produced with a CO{sub 2} laser using 6-mm-thick steel plates. In addition to the testing of flat microtensile specimens, the mechanical properties were examined by microhardness survey and conventional transverse and round tensile specimens. The results of the microtensile specimens were compared with standard round tensile specimens, and this clearly showed the suitability of the microtensile specimen technique for such joints. The crack tip opening displacement (CTOD) tests were also performed to determine the fracture toughness of the LB welds using three-point bend specimens. The effect of strength heterogeneity (mismatching) across the weld joint and at the vicinity of the crack tip on the CTOD fracture toughness values was also discussed.

Cam, G.; Kocak, M. [GKSS Research Center, Geesthacht (Germany). Inst. of Materials Research; Erim, S.; Yeni, C. [Dokuz Eyluel Univ., Izmir (Turkey). Mechanical Engineering Dept.

1999-06-01T23:59:59.000Z

404

The Role of Friction Stir Welding in Nuclear Fuel Plate Fabrication  

SciTech Connect (OSTI)

The friction bonding process combines desirable attributes of both friction stir welding and friction stir processing. The development of the process is spurred on by the need to fabricate thin, high density, reduced enrichment fuel plates for nuclear research reactors. The work seeks to convert research and test reactors currently operating on highly enriched uranium fuel to operate on low enriched uranium fuel without significant loss in reactor performance, safety characteristics, or significant increase in cost. In doing so, the threat of global nuclear material proliferation will be reduced. Feasibility studies performed on the process show that this is a viable option for mass production of plate-type nuclear fuel. Adapting the friction stir weld process for nuclear fuel fabrication has resulted in the development of several unique ideas and observations. Preliminary results of this adaptation and process model development are discussed.

D Burkes; P Medvedev; M Chapple; A Amritkar; P Wells; I Charit

2009-02-01T23:59:59.000Z

405

EFFECT OF TOOL FEATURE ON THE JOINT STRENGTH OF DISSIMILAR FRICTION STIR LAP WELDS  

SciTech Connect (OSTI)

Several variations of friction stir tools were used to investigate the effects on the joint strengths of dissimilar friction stir lap welds. In the present lap weld configuration the top sheet was a 2.32 mm thick Mg (AZ 31) alloy. The bottom sheet consisted of two different steels, a (i) 0.8 mm thick electro-galvanized (EG) mild steel, or a (ii) 1.5 mm thick hot dip galvanized (HDG) high strength low alloy (HSLA) steel. Initially the tool shape was modified to accommodate the material, at which point the tool geometry was fixed. With a fixed tool geometry an additional feature was added to the pin bottom on one of the tools by incorporating a short hard insert, which would act as a stronger bottom sheet cutter. The effects of such modification on the unguided lap shear strength, and associated microstructural changes are discussed in this study.

Jana, Saumyadeep; Hovanski, Yuri; Grant, Glenn J.; Mattlin, Karl F.

2011-04-25T23:59:59.000Z

406

Managing the Management: CORBAbased Instrumentation of Management Systems  

E-Print Network [OSTI]

Management Team Department of Computer Science, TU M? unchen Arcisstr. 21, D­80333 Munich, Germany akeller approach to this problem by defining a MIB for manage­ ment systems. It can be regarded as a step towardsManaging the Management: CORBA­based Instrumentation of Management Systems A. Keller Munich Network

407

PROTOCOL FOR EXAMINATION OF THE INNER CAN CLOSURE WELD REGION FOR 3013 DE CONTAINERS  

SciTech Connect (OSTI)

The protocol for the examination of the inner can closure weld region (ICCWR) for 3013 DE containers is presented within this report. The protocol includes sectioning of the inner can lid section, documenting the surface condition, measuring corrosion parameters, and storing of samples. This protocol may change as the investigation develops since findings may necessitate additional steps be taken. Details of the previous analyses, which formed the basis for this protocol, are also presented.

Mickalonis, J.

2014-09-16T23:59:59.000Z

408

Preliminary design and definition of field experiments for welded tuff rock mechanics program  

SciTech Connect (OSTI)

The preliminary design contains objectives, typical experiment layouts, definitions of equipment and instrumentation, test matrices, preliminary design predictive modeling results for five experiments, and a definition of the G-Tunnel Underground Facility (GTUF) at the Nevada Test Site where the experiments are to be located. Experiments described for investigations in welded tuff are the Small Diameter Heater, Unit Cell-Canister Scale, Heated Block, Rocha Slot, and Miniature Heater.

Zimmerman, R.M.

1982-06-01T23:59:59.000Z

409

Stress bij eerstejaars geneeskundestudenten in Groningen  

Science Journals Connector (OSTI)

Veel geneeskundestudenten ervaren stress. Stress kan een negatieve invloed hebben op de gezondheid, de studie en de carrire. In dit onderzoek werd de prevalentie van stresservaring bij eerstej...

A. H. Hornstra; J. P. C. Jaspers

2003-12-01T23:59:59.000Z

410

Category:Stress Test | Open Energy Information  

Open Energy Info (EERE)

Category Edit History Facebook icon Twitter icon Category:Stress Test Jump to: navigation, search Geothermalpower.jpg Looking for the Stress Test page? For detailed information...

411

Effects of residual stresses on constraint and fracture behaviour of wide plates  

Science Journals Connector (OSTI)

...Symp. on Mismatching of Welds, Interfaces and Performance of Strength Mismatched Welded or Bonded Joints, Reinstorf- L uneburg, Germany, 2426/4/96. GKSS Research Centre Geesthacht, Germany. Proc. R. Soc. Lond. A (1998)

1998-01-01T23:59:59.000Z

412

Advanced Ultrasonic Inspection Techniques for General Purpose Heat Source Fueled Clad Closure Welds  

SciTech Connect (OSTI)

A radioisotope thermoelectric generator is used to provide a power source for long-term deep space missions. This General Purpose Heat Source (GPHS) is fabricated using iridium clad vent sets to contain the plutonium oxide fuel pellets. Integrity of the closure weld is essential to ensure containment of the plutonium. The Oak Ridge Y-12 Plant took the lead role in developing the ultrasonic inspection for the closure weld and transferring the inspection to Los Alamos National Laboratory for use in fueled clad inspection for the Cassini mission. Initially only amplitude and time-of-flight data were recorded. However, a number of benign geometric conditions produced signals that were larger than the acceptance threshold. To identify these conditions, a B-scan inspection was developed that acquired full ultrasonic waveforms. Using a test protocol the B-scan inspection was able to identify benign conditions such as weld shield fusion and internal mismatch. Tangential radiography was used to confirm the ultrasonic results. All but two of 29 fueled clads for which ultrasonic B-scan data was evaluated appeared to have signals that could be attributed to benign geometric conditions. This report describes the ultrasonic inspection developed at Y-12 for the Cassini mission.

Moyer, M.W.

2001-01-11T23:59:59.000Z

413

Significant changes in the Code rules in Section VIII, Division 1 concerning material and welding  

SciTech Connect (OSTI)

Several very significant changes to the Code rules in Section VIII, Division 1 concerning materials and welding have been made since the 1950 Code. These changes include: (1) Improved steel making practice which has resulted in significant changes to the type of materials permitted for the construction of Section VIII vessels. (2) In 1950 no impact testing was required on any material for use at temperatures of {minus}20F and above. And when impact testing was required, the impact value was 15 ft-lb minimum average on Charpy type, keyhole, or U-notch specimens. (3) In the mid-1960`s, the impact test requirement was changed to Charpy type, V-notch specimens, a much more severe test. (4) In 1987 the Code published new toughness rules for carbon and low-alloy steels. (5) In regard to welding, a very significant improvement has been the use of low-hydrogen electrodes which started in the 1950`s. Few welding electrode specifications existed in the early editions of the Code. A recent improvement in electrode specification is moisture resistant electrodes.

Doty, W.D. [Doty and Associates, Pittsburgh, PA (United States)

1996-12-01T23:59:59.000Z

414

The effect of electromagnetic forces on the penetrator formation during high-frequency electric resistance welding  

Science Journals Connector (OSTI)

During high-frequency electric resistance welding (HF-ERW), the electromagnetic force induced by the high-frequency electric current was studied to improve the understanding of penetrator formation mechanism. ERW melting zone behavior is investigated by the cinematography and the three-dimensional numerical analysis of electromagnetic field around molten metal bridge. Based on the results, the penetrator formation is mainly influenced by the narrow gap shape, the variation of electromagnetic forces along the narrow gap, the molten metal bridge traveling speed, and the second bridge formation frequency. Electromagnetic force acting on the molten metal bridge is rapidly decreasing as the bridge is traveling away from the apex point. The comet shape narrow gap produced by the variation of Lorentz forces makes the bridge pushing pressure decrease. Due to the decrease of electromagnetic force and pushing pressure, the sweeping speed of molten metal bridge slows down until the bridge reaches the welding point. Previous molten metal bridge traveling is arrested when the next bridge is formed before the previous bridge arrives at the welding point. Thus, the molten metal and oxide are refilled into the narrow gap due to the capillary force and then remained as a penetrator. According to the analysis of penetrator formation mechanism, the new penetrator formation model is proposed.

Choong-Myeong Kim; Jung-Kyu Kim

2009-01-01T23:59:59.000Z

415

Fabrication Flaw Density and Distribution In Repairs to Reactor Pressure Vessel and Piping Welds  

SciTech Connect (OSTI)

The Pacific Northwest National Laboratory is developing a generalized fabrication flaw distribution for the population of nuclear reactor pressure vessels and for piping welds in U.S. operating reactors. The purpose of the generalized flaw distribution is to predict component-specific flaw densities. The estimates of fabrication flaws are intended for use in fracture mechanics structural integrity assessments. Structural integrity assessments, such as estimating the frequency of loss-of-coolant accidents, are performed by computer codes that require, as input, accurate estimates of flaw densities. Welds from four different reactor pressure vessels and a collection of archived pipes have been studied to develop empirical estimates of fabrication flaw densities. This report describes the fabrication flaw distribution and characterization in the repair weld metal of vessels and piping. This work indicates that large flaws occur in these repairs. These results show that repair flaws are complex in composition and sometimes include cracks on the ends of the repair cavities. Parametric analysis using an exponential fit is performed on the data. The relevance of construction records is established for describing fabrication processes and product forms. An analysis of these records shows there was a significant change in repair frequency over the years when these components were fabricated. A description of repair flaw morphology is provided with a discussion of fracture mechanics significance. Fabrication flaws in repairs are characterized using optimized-access, high-sensitivity nondestructive ultrasonic testing. Flaw characterizations are then validated by other nondestructive evaluation techniques and complemented by destructive testing.

GJ Schuster, FA Simonen, SR Doctor

2008-04-01T23:59:59.000Z

416

Managing Solutions  

E-Print Network [OSTI]

tx H2O | pg. 19 Texas Water Resources Institute (TWRI) project managers work together with scientists and educators as well as government funding agencies to address water quality and quantity issues in Texas. Each of TWRI?s five project... the funds.? Gregory began his role at TWRI in 2006 upon com- pletion of a master?s degree in water management and hydrological science at Texas A&M University. A former Mills Scholar, Gregory was familiar with TWRI. He saw that the institute...

Baker, Emily

2007-01-01T23:59:59.000Z

417

Intergranular stresses in ZIRCALOY-2  

Science Journals Connector (OSTI)

The development of the understanding of the intergranular stresses in ZIRCALOY-2 is reviewed. Neutron diffraction measurements of the intergranular strains were made on rod-textured material and highly texture...

T. M. Holden; J. W. L. Pang; R. A. Holt

2002-03-01T23:59:59.000Z

418

Microstructures and mechanical properties of Ti-6Al-4V welds with filler additions of tantalum and FS85  

SciTech Connect (OSTI)

Many applications in the nuclear industry require that titanium alloys be welded to refractory metal alloys. Because of the widely dissimilar properties of these materials, the homogeneity of the fusion zone os of particular concern. To address this issue, a study was conducted to characterize the fusion zones of Ti-6Al-4V welds made with filler additions of tantalum and FS85 (Nb-28Wt%Ta-10wt%W-1wt%Zr). A goal of this study was to evaluate the feasibility of making microstructural predictions based on calculated fusion zone electron/atom (e/a) ratios. The welds were made by placing tantalum or FS85 shims between two pieces of 2.5 mm (0.1 in.) thick Ti-6Al-4V and making an electron beam weld along the length of the shim. With complete mixing, these shims were expected to produce fusion zone e/a ratios of 3.63{emdash}4.14 for the Ta series and 3.63{emdash}4.06 for the FS85 series, and microstructures consisting of {alpha}`, {alpha}`, and perhaps {omega}. The weld macro- and microstructures were characterized using optical and electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction. The mechanical properties of the welds were assessed using transverse and all-weld-metal tensile tests. The results showed a general increase in strength and decrease in ductility with increasing {beta} stabilizer level. As a result of this study, parameters were developed to increase the fusion zone size and increase mixing of the components. This work was performed at Sandia National Laboratories, supported by the U.S. Department of Energy under contract number DE-AC04-76DR00789, and at Los Alamos National Laboratory under contract number W-7405-ENG-36.

Damkroger, B.K.; Dixon, R.D.; Cotton, J.D.

1994-12-31T23:59:59.000Z

419

LTS Project Management - Hanford Site  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Transition LTS Execution Project Management Planning Resource Management Reporting Interface Management Communications (InternalExternal) Information Management Records...

420

Risk management  

SciTech Connect (OSTI)

In the autumn of 1993 an incident occurred with a diving support vessel, whereby a live pipeline from a NAM gas production platform, situated in the Dutch sector of the North Sea, was considerably displaced. Key element in the repair of the line was to identify potential hazards involved in various remedial scenarios and to manage the associated risks.

Visser, M. [Nederlandse Aardolie Maatschappij, Velsen (Netherlands)

1995-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Original article Growth stresses in tension wood  

E-Print Network [OSTI]

Original article Growth stresses in tension wood: role of microfibrils and lignification T Okuyama the growth stress generation in the region of normal and tension woods. growth stress/ tension wood in normal and ten- sion wood. The compressive stress from the deposition of lignin controls the level

Paris-Sud XI, Université de

422

Chronic stress elevates telomerase activity in rats  

Science Journals Connector (OSTI)

...Chronic stress elevates telomerase activity in rats Annaliese K. Beery 1 * Jue Lin 2 Joshua...unpredictable stress on telomerase activity in male rats. Telomerase activity was 54 per cent higher in stressed rats than in controls, and associated with stress-related...

2012-01-01T23:59:59.000Z

423

Data Management Policy | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Data Management Policy Data Management Policy The data management resource information and data release policies below are provided to help researchers understand the data...

424

Object Management Systems  

E-Print Network [OSTI]

Object-Oriented Database Management Systems for EngineeringR. Cassel. Distribution Management Systems: Functions and8-PWR 1988. Network Management Systems 52 Subodh Bapat.

Gollu, Aleks Ohannes

1995-01-01T23:59:59.000Z

425

Environmental Management System  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Management System Environmental Management System An Environmental Management System is a systematic method for assessing mission activities, determining the environmental impacts...

426

Environmental Management System Plan  

E-Print Network [OSTI]

R-3 Environmental Management System Plan References 30.of Energy, Safety Management System Policy, DOE P 450.4 (E), Environmental Management Systems ? Requirements with

Fox, Robert

2009-01-01T23:59:59.000Z

427

Federal Energy Management Program: Best Management Practice: Cooling Tower  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Cooling Tower Management to someone by E-mail Cooling Tower Management to someone by E-mail Share Federal Energy Management Program: Best Management Practice: Cooling Tower Management on Facebook Tweet about Federal Energy Management Program: Best Management Practice: Cooling Tower Management on Twitter Bookmark Federal Energy Management Program: Best Management Practice: Cooling Tower Management on Google Bookmark Federal Energy Management Program: Best Management Practice: Cooling Tower Management on Delicious Rank Federal Energy Management Program: Best Management Practice: Cooling Tower Management on Digg Find More places to share Federal Energy Management Program: Best Management Practice: Cooling Tower Management on AddThis.com... Sustainable Buildings & Campuses Operations & Maintenance

428

Federal Energy Management Program: Best Management Practice: Water  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Water Management Planning to someone by E-mail Water Management Planning to someone by E-mail Share Federal Energy Management Program: Best Management Practice: Water Management Planning on Facebook Tweet about Federal Energy Management Program: Best Management Practice: Water Management Planning on Twitter Bookmark Federal Energy Management Program: Best Management Practice: Water Management Planning on Google Bookmark Federal Energy Management Program: Best Management Practice: Water Management Planning on Delicious Rank Federal Energy Management Program: Best Management Practice: Water Management Planning on Digg Find More places to share Federal Energy Management Program: Best Management Practice: Water Management Planning on AddThis.com... Sustainable Buildings & Campuses Operations & Maintenance

429

Managing Critical Management Improvement Initiatives  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

Provides requirements and responsibilities for planning, executing and assessing critical management improvement initiatives within DOE. DOE N 251.59, dated 9/27/2004, extends this Notice until 10/01/2005. Archived 11-8-10. Does not cancel other directives.

2003-10-01T23:59:59.000Z

430

Effects of alloying elements on the strength and cooling rate sensitivity of ultra-low carbon alloy steel weld metals. Technical report  

SciTech Connect (OSTI)

A study was conducted to evaluate the effect of weld cooling rate on the strength of autogenous GTAW deposited weld metal. The basic weld metal composition was based on a low carbon bainite metallurgical system. The weld metal yield strength goal was 130 ksi, needed to surpass the current HY-13O weld metal requirements. Vacuum Induction Melted (VIM) heats of steel were produced and processed into 3/4` thickness plates. The autogenous gas tungsten arc welds (GTAW) on the parent steel plates were produced under two different heat input conditions. Tensile specimens were produced from the weldments; specimens from certain heats were subjected to gleeble thermal simulations of multi-pass welding conditions using the Gleeble 1500. All specimens were then evaluated for yield and ultimate tensile strength. From the data presented, it was found that the experimental compositions studied were less sensitive to cooling rate than current HY-130 welding consumables. The compositions tested approached the target yield strength of 130 ksi, but further work is necessary in this area.

Vassilaros, M.G.

1994-03-01T23:59:59.000Z

431

Research on micro-electric resistance slip welding of copper electrode during the fabrication of 3D metal micro-mold  

Science Journals Connector (OSTI)

Abstract 3D micro-mold fabricated by the micro double-staged laminated object manufacturing process (micro-DLOM) is formed via stacking and fitting of multi-layer 2D micro-structures. The connection of 2D micro-structures is related to forming accuracy and mechanical properties of 3D micro-mold. In this research, micro-electric resistance slip welding of copper electrodes was proposed to connect multi-layer 2D micro-structures. Firstly, the proper process parameters of slip welding were obtained through the welding experiment, and the temperature field of micro-electric resistance slip welding under such process parameters was simulated. Secondly, deposition effect of the copper bar electrode produced during slip welding was studied and the study results show that the copper element deposited in the slip welding area decreases as the surface roughness of copper electrode decreases. Finally, based on the above research, a square micro-cavity mold with micro-channel, a circular micro-cavity mold with cross keyway and micro gear cavity mold with two-stage steps were welded by the micro-electric resistance slip welding.

Bin Xu; Xiao-yu Wu; Jian-guo Lei; Feng Luo; Feng Gong; Chen-lin Du; Xiu-quan Sun; Shuang-chen Ruan

2013-01-01T23:59:59.000Z

432

Environmental Management  

SciTech Connect (OSTI)

Another key aspect of the NNSS mission is Environmental Management program, which addresses the environmental legacy from historic nuclear weapons related activities while also ensuring the health and safety of present day workers, the public, and the environment as current and future missions are completed. The Area 5 Radioactive Waste Management site receives low-level and mixed low-level waste from some 28 different generators from across the DOE complex in support of the legacy clean-up DOE Environmental Management project. Without this capability, the DOE would not be able to complete the clean up and proper disposition of these wastes. The program includes environmental protection, compliance, and monitoring of the air, water, plants, animals, and cultural resources at the NNSS. Investigation and implementation of appropriate corrective actions to address the contaminated ground water facilities and soils resulting from historic nuclear testing activities, the demolition of abandoned nuclear facilities, as well as installation of ground water wells to identify and monitor the extent of ground water contamination.

None

2014-11-12T23:59:59.000Z

433

Environmental Management  

ScienceCinema (OSTI)

Another key aspect of the NNSS mission is Environmental Management program, which addresses the environmental legacy from historic nuclear weapons related activities while also ensuring the health and safety of present day workers, the public, and the environment as current and future missions are completed. The Area 5 Radioactive Waste Management site receives low-level and mixed low-level waste from some 28 different generators from across the DOE complex in support of the legacy clean-up DOE Environmental Management project. Without this capability, the DOE would not be able to complete the clean up and proper disposition of these wastes. The program includes environmental protection, compliance, and monitoring of the air, water, plants, animals, and cultural resources at the NNSS. Investigation and implementation of appropriate corrective actions to address the contaminated ground water facilities and soils resulting from historic nuclear testing activities, the demolition of abandoned nuclear facilities, as well as installation of ground water wells to identify and monitor the extent of ground water contamination.

None

2015-01-07T23:59:59.000Z

434

Best Management Practice #1: Water Management Planning  

Broader source: Energy.gov [DOE]

A successful water management program starts with developing a comprehensive water management plan. This plan should be included within existing facility operating plans.

435

Contract Management Certificate Program  

E-Print Network [OSTI]

Contract Management Certificate Program Accelerate Your Career BusinessandManagement extension bearing the UC seal signifies a well- known, uncompromising standard of academic excellence. #12;Contract Management Certificate Program UC Irvine Extension's Contract Management Certificate Program focuses on core

Rose, Michael R.

436

Automated Flaw Detection Scheme For Cast Austenitic Stainless Steel Weld Specimens Using Hilbert Huang Transform Of Ultrasonic Phased Array Data  

SciTech Connect (OSTI)

The objective of this work is to develop processing algorithms to detect and localize the flaws using NDE ultrasonic data. Data was collected using cast austenitic stainless steel (CASS) weld specimens on-loan from the U.S. nuclear power industrys Pressurized Water Reactor Owners Group (PWROG) specimen set. Each specimen consists of a centrifugally cast stainless steel (CCSS) pipe section welded to a statically cast (SCSS) or wrought (WRSS) section. The paper presents a novel automated flaw detection and localization scheme using low frequency ultrasonic phased array inspection signals in the weld and heat affected zone of the base materials. The major steps of the overall scheme are preprocessing and region of interest (ROI) detection followed by the Hilbert Huang transform (HHT) of A-scans in the detected ROIs. HHT offers time-frequency-energy distribution for each ROI. The accumulation of energy in a particular frequency band is used as a classification feature for the particular ROI.

Khan, T.; Majumdar, Shantanu; Udpa, L.; Ramuhalli, Pradeep; Crawford, Susan L.; Diaz, Aaron A.; Anderson, Michael T.

2012-01-01T23:59:59.000Z

437

Mechanical strength evaluation for Nd-YAG laser and electric resistance spot weld (ERSW) joint under multiaxial loading  

Science Journals Connector (OSTI)

This work presents a comparison between laser weld (LBW) and electric resistance spot weld (ERSW) processes used for assemblies of components in a body-in-white (BIW) at a world class automotive industry. It is carried out by evaluating the mechanical strength modeled both by experimental and numerical methods. An Arcan multiaxial test was designed and manufactured in order to enable 0, 45 and 90 directional loadings. The welded specimens were uncoated low carbon steel sheets (Sy=170MPa) used currently at the automotive industry, with two different thicknesses: 0.80 and 1.20mm. A numerical analysis was carried out using the finite element method (FEM) through LS-DYNA code.

Haroldo Akira Kavamura; Gilmar Ferreira Batalha

2008-01-01T23:59:59.000Z

438

Your Records Management Responsibilities  

Broader source: Energy.gov (indexed) [DOE]

Your Records Management Your Records Management Responsibilities Table of Contents INTRODUCTION RECORDS MANAGEMENT IN THE FEDERAL GOVERNMENT RECORDS MANAGEMENT IN THE DEPARTMENT OF ENERGY IMPORTANCE OF RECORDS MANAGEMENT YOUR RECORDS MANAGEMENT RESPONSIBILITIES RECORDS MANAGEMENT LIFE CYCLE ELECTRONIC RECORDS & RECORDKEEPING LAW, REGULATION, AND POLICY ASSISTANCE RECORDS MANAGEMENT TERMS 2 INTRODUCTION If you are a government employee or contractor working for a federal agency, records management is part of your job. This pamphlet explains your responsibilities for federal records and provides the context for understanding records management in the federal government and in the Department of Energy. TOP RECORDS MANAGEMENT IN THE FEDERAL GOVERNMENT

439

Integrated Safety Management Policy  

Broader source: Energy.gov (indexed) [DOE]

INTEGRATED SAFETY INTEGRATED SAFETY MANAGEMENT SYSTEM DESCRIPTION U.S. DEPARTMENT OF ENERGY Office of Environmental Management Headquarters May 2008 Preparation: Braj K. sin& Occupational Safety and Health Manager Office of Safety Management Concurrence: Chuan-Fu wu Director, Offlce of Safety Management Deputy Assistant Secretary for safe& Management andoperations Operations Officer for 1 Environmental Management Approval: Date p/-g Date Environmental Management TABLE OF CONTENTS ACRONYMS................................................................................................................................................................v EXECUTIVE SUMMARY .........................................................................................................................................1

440

Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material  

SciTech Connect (OSTI)

Stress corrosion cracking is one of the most common corrosion-related causes for premature breach of metal structural components. Stress corrosion cracking is the initiation and propagation of cracks in structural components due to three factors that must be present simultaneously: metallurgical susceptibility, critical environment, and static (or sustained) tensile stresses. This report was prepared according to ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The purpose of this report is to provide an evaluation of the potential for stress corrosion cracking of the engineered barrier system components (i.e., the drip shield, waste package outer barrier, and waste package stainless steel inner structural cylinder) under exposure conditions consistent with the repository during the regulatory period of 10,000 years after permanent closure. For the drip shield and waste package outer barrier, the critical environment is conservatively taken as any aqueous environment contacting the metal surfaces. Appendix B of this report describes the development of the SCC-relevant seismic crack density model (SCDM). The consequence of a stress corrosion cracking breach of the drip shield, the waste package outer barrier, or the stainless steel inner structural cylinder material is the initiation and propagation of tight, sometimes branching, cracks that might be induced by the combination of an aggressive environment and various tensile stresses that can develop in the drip shields or the waste packages. The Stainless Steel Type 316 inner structural cylinder of the waste package is excluded from the stress corrosion cracking evaluation because the Total System Performance Assessment for License Application (TSPA-LA) does not take credit for the inner cylinder. This document provides a detailed description of the process-level models that can be applied to assess the performance of Alloy 22 (used for the waste package outer barrier) and Titanium Grade 7 (used for the drip shield) that are subjected to the effects of stress corrosion cracking. The use of laser peening or other residual stress mitigation techniques is considered as a means of mitigating stress corrosion cracking in the waste package final closure lid weld.

G. Gordon

2004-10-13T23:59:59.000Z

Note: This page contains sample records for the topic "welding stress management" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Dissimilar-alloy laser welding of titanium: Ti6Al-4V to Beta-C{trademark}  

SciTech Connect (OSTI)

Beta-C{sup TM} is a metastable-beta titanium alloy (nominal composition: Ti-3wt%Al-8wt%V-6wtTCr-4wt%Mo-4wt%Zr) which can be thermomechanically processed and heat treated to provide excellent combinations of strength, ductility, and fracture toughness. Recently, the increased application of metastable-beta titanium alloys in aerospace and commercial applications has resulted in the necessity to join these alloys to conventional alpha-beta titanium alloys. Based on this previous work, two approaches were considered for improving the ductility of dissimilar-alloy welds between Ti-6Al-4V and Beta-C{sup TM} in the present study: (1) application of a low heat input welding process to minimize the fusion zone and heat-affected zone (HAZ) beta grain size and (2) modification of the fusion zone chemical composition to allow greater microstructural optimization through postweld aging. CO{sub 2} laser welds were produced between Ti-6Al-4V and Beta-C{sup TM} sheet. Three different nominal fusion zone chemical compositions were obtained by varying the laser beam locations relative to the joint centerline and thereby melting different quantities of each base metal. For comparable postweld aging conditions, the laser welds exhibited ductilities superior to those of coarse-grained gas tungsten arc welds. Fracture analysis of the weld zone revealed a transition from a predominantly transgranular fracture in the low-temperature aged conditions to increasingly intergranular fracture following aging at higher temperature. This transition was promoted by an increase in the thickness and continuity of alpha phase at beta grain boundaries.

Liu, P.S.; Baeslack, W.A. III; Hurley, J.

1994-12-31T23:59:59.000Z

442

The application of the fusion method of thermit welding to small diameter tubing: An analysis of joint geometry.  

E-Print Network [OSTI]

by working (g:zs3). Thermit weld metal can be regarded as having physical properties closely approaching those of forged steel (l3:2S3). In summary, the thermit process. . . . . . has been used in almost every industry (I:17-2D). Llhile the plastic... (February 19, 1970). 3. Davies, A. C. , The Science and Practice of Lleldin Cambridge University Press 1941 4. Deppeler, 3. H. , "Thermit Welding and the Steel Mill, " 3ournal of the American Weldin Societ 10, (May 1931 5. Deppeler, 3. H. , "Thermit...

Glynn, Thomas Michael

2012-06-07T23:59:59.000Z

443

Mechanical properties of welds in commercial alloys for high-temperature gas-cooled reactor components  

SciTech Connect (OSTI)

Weld properties of Hastelloy-X, Incoloy alloy 800H (with and without Inconel-82 cladding), and 2 1/4 Cr-1 Mo are being studied to provide design data to support the development of steam generator, core auxiliary heat exchanger, and metallic thermal barrier components of the high-temperature gas-cooled reactor (HTGR) steam cycle/cogeneration plant. Tests performed include elevated-temperature creep rupture tests and tensile tests. So far, data from the literature and from relatively short-term tests at GA Technologies Inc. indicate that the weldments are satisfactory for HTGR application.

Lindgren, J.R.; Li, C.C.; Ryder, R.H.; Thurgood, B.E.

1984-07-01T23:59:59.000Z

444

Energy management  

SciTech Connect (OSTI)

This paper is a review of the Department of Energy's (DOE) Contractor Purchasing System Review (CPSR) Program, which oversees the extensive subcontracting activities of the Department's management and operating (M and O) contractors. This review is part of a special GAO audit effort to help ensure that areas vulnerable to fraud, waste, abuse, and mismanagement are identified and that adequate corrective actions are taken. This effort focuses on 16 areas, one of which is DOE contractor oversight. This report describes the subcontracting deficiencies occurring at DOE, identifies shortcomings in DOE's CPSR Program, and discusses the corrective actions that DOE has committed to take in its CPSR Program in response to these findings.

Glenn, J.

1991-10-01T23:59:59.000Z

445

Health Psychology What is Stress?  

E-Print Network [OSTI]

environment 2) Some Definitions: a) Generic- demands exceed capacity - engineering origins b) Biological stress responses, and (e) physical and mental health outcomes #12;Person-Environment Fit ! Sufficient-capability imbalance in the organism's vital adjustment and which is partially manifested by a nonspecific response

Meagher, Mary

446

Holographic in situ stress measurements  

Science Journals Connector (OSTI)

......surrounding a single borehole. (2) To...require a drilling rig to operate...so that a large amount of...obtained in a borehole farther removed...instrument is too large for deployment...model of the borehole wall response to drilling a stress-relief......

Jay D. Bass; Douglas Schmitt; Thomas J. Ahrens

1986-04-01T23:59:59.000Z

447

M E Environmental Management Environmental Management  

Broader source: Energy.gov (indexed) [DOE]

safety  performance  cleanup  closure safety  performance  cleanup  closure M E Environmental Management Environmental Management M E Environmental Management Environmental Management Office of Site Restoration, EM-10 Office of D&D and Facility Engineering, EM-13 Facility Deactivation & Decommissioning (D&D) D&D Program Map Addendum: Impact of American Recovery and Reinvestment Act (ARRA) on EM's D&D Program 2013 Edition U.S. Department Of Energy safety  performance  cleanup  closure M E Environmental Management Environmental Management safety  performance  cleanup  closure M E Environmental Management Environmental Management M E Environmental Management Environmental Management 3/13/2013 The American Recovery and Reinvestment Act of 2009

448

Stress development and shape change during press-hardening process using phase-transformation-based finite element analysis  

Science Journals Connector (OSTI)

Abstract Elastically driven shape change, or springback, in a press-hardened U-channel part made from a tailor-welded blank (TWB) was simulated using a fully coupled thermo-mechanicalmetallurgical finite element (FE) method. The TWB consists of boron steel and high-strength low-alloy steel, which have significantly different hardenabilities. A combined implicitexplicit three-step simulation consisting of air cooling, forming and die quenching, and springback was used for computational efficiency. All the required material models such as the modified phase-transformation kinetics and phase-transformation-related stress-update scheme were implemented in the FE software ABAQUS with the user-defined subroutines UMAT, VUMAT, and HETVAL. The developed FE procedure, including the material models, satisfactorily predicted the experimentally measured shape changes of the TWB part. Here we present an in-depth analysis of the residual stress development during forming and die quenching using different material modeling schemes. It should be noted that the stress evolution of the two materials with high and low hardenabilities were significantly different depending on the phase transformation kinetics during forming and quenching. Moreover, in order to enhance the prediction capability of the press-hardening simulations, it was essential to include the phase-transformation-related strains in the material model.

H.H. Bok; J.W. Choi; D.W. Suh; M.G. Lee; F. Barlat

2014-01-01T23:59:59.000Z

449

Heat Stress - HPMC Occupational Health Services  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Awareness Cold and Flu Prevention Hand Washing Healthy Sleep Heat Stress Radon Signs of a Heart Attack Signs of a Stroke Distracted Driving Coping with Stress & Change Skin Cancer...

450

Social buffering: relief from stress and anxiety  

Science Journals Connector (OSTI)

...Lundeberg, T2002Social stress blocks energy conservation in rats exposed to an oxytocin-injected...unwanted pregnancies. Am. J. Public Health. 63, 935-938. Morris...relief from stress and anxiety. | Communication is essential to members of a...

2006-01-01T23:59:59.000Z

451

Determination of Longitudinal Stress in Rails  

E-Print Network [OSTI]

The objective of this research is to determine the longitudinal stress in rails by using the polarization of Rayleigh waves. Analytical models are developed to describe the effect of applied stress on wave speed and on the polarization of Rayleigh...

Djayaputra, Ferdinand

2012-02-14T23:59:59.000Z

452

Joining aluminum to titanium alloy by friction stir lap welding with cutting pin  

SciTech Connect (OSTI)

Aluminum 1060 and titanium alloy Ti-6Al-4V plates were lap joined by friction stir welding. A cutting pin of rotary burr made of tungsten carbide was employed. The microstructures of the joining interface were observed by scanning electron microscopy. Joint strength was evaluated by a tensile shear test. During the welding process, the surface layer of the titanium plate was cut off by the pin, and intensively mixed with aluminum situated on the titanium plate. The microstructures analysis showed that a visible swirl-like mixed region existed at the interface. In this region, the Al metal, Ti metal and the mixed layer of them were all presented. The ultimate tensile shear strength of joint reached 100% of 1060Al that underwent thermal cycle provided by the shoulder. - Highlights: Black-Right-Pointing-Pointer FSW with cutting pin was successfully employed to form Al/Ti lap joint. Black-Right-Pointing-Pointer Swirl-like structures formed due to mechanical mixing were found at the interface. Black-Right-Pointing-Pointer High-strength joints fractured at Al suffered thermal cycle were produced.

Wei, Yanni [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072 (China) [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072 (China); Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi'an 710072 (China); Li, Jinglong, E-mail: lijinglg@nwpu.edu.cn [Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi'an 710072 (China)] [Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi'an 710072 (China); Xiong, Jiangtao [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072 (China) [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072 (China); Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi'an 710072 (China); Huang, Fu; Zhang, Fusheng; Raza, Syed Hamid [Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi'an 710072 (China)] [Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi'an 710072 (China)

2012-09-15T23:59:59.000Z

453

Welding Robot and Remote Handling System for the Yucca Mountain Waste Package Closure System  

SciTech Connect (OSTI)

In preparation for the license application and construction of a repository for housing the nation's spent nuclear fuel and high-level waste in Yucca Mountain, the Idaho National Laboratory (INL) has been charged with preparing a mock-up of a full-scale prototype system for sealing the waste packages (WP). Three critical pieces of the closure room include two PaR Systems TR4350 Telerobotic Manipulators and a PaR Systems XR100 Remote Handling System (RHS). The TR4350 Manipulators are 6-axis programmable robots that will be used to weld the WP lids and purge port cap as well as conduct nondestructive examinations. The XR100 Remote Handling System is a 4-axis programmable robot that will be used to transport the WP lids and process tools to the WP for operations and remove equipment for maintenance. The welding and RHS robots will be controlled using separate PaR 5/21 CIMROC Controllers capable of complex motion control tasks. A tele-operated PaR 4350 Manipulator will also be provided with the XR100 Remote Handling System. It will be used for maintenance and associated activities within the closure room. (authors)

Barker, M.E.; Holt, T.E.; LaValle, D.R. [PaR Systems, Inc., Shoreview, MN (United States); Pace, D.P.; Croft, K.M.; Shelton-Davis, C.V. [Battelle Energy Alliance, LLC/Idaho National Laboratory, Idaho Falls, ID (United States)

2008-07-01T23:59:59.000Z