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Note: This page contains sample records for the topic "optimize welding conditions" 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

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.

2

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. Keywords—Genetic algorithm, Pulsed GMA welding, Welding parameters, Depth of penetration, Regression mode I.

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

3

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

4

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

5

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

6

On Second Order Optimality Conditions in Nonlinear Optimization  

E-Print Network [OSTI]

Aug 15, 2014 ... Abstract: In this work we present new weak conditions that ensure the validity of necessary second order optimality conditions (SOC) for ...

Roberto Andreani

2014-08-15T23:59:59.000Z

7

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 â?? p 0 , i.e., when p â?? 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

8

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

9

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

10

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.

11

SciTech Connect: optimal initial conditions for coupling ice...  

Office of Scientific and Technical Information (OSTI)

Conference: optimal initial conditions for coupling ice sheet models to earth system models Citation Details In-Document Search Title: optimal initial conditions for coupling ice...

12

Aerodynamic Optimization Under a Range of Operating Conditions  

E-Print Network [OSTI]

Aerodynamic Optimization Under a Range of Operating Conditions David W. Zingg and Samy Elias. This can be achieved through multipoint optimization. The desired performance objective and operating conditions must be speci ed, and the resulting optimization problem must be solved in such a manner

Zingg, David W.

13

On Aerodynamic Optimization Under a Range of Operating Conditions  

E-Print Network [OSTI]

On Aerodynamic Optimization Under a Range of Operating Conditions David W. Zingg, and Samy Elias In aerodynamic design, good performance is generally required under a range of oper- ating conditions, including aerodynamic shape optimization.1­6 The designer specifies an objective, operating conditions, constraints

Zingg, David W.

14

On Second Order Optimality Conditions in Nonlinear Optimization  

E-Print Network [OSTI]

Aug 15, 2014 ... [20] Jorge Nocedal and Stephen J. Wright. Numerical optimization. Springer,. New York, 2nd ed. edition, 2006. [21] R. Tyrrell Rockafellar.

2014-08-15T23:59:59.000Z

15

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

16

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

17

An Investigation of Optimal Vehicle Maneuvers for Different Road Conditions  

E-Print Network [OSTI]

vehicle maneuvers in time-critical situations have emerged as powerful tools during the past years. EvenAn Investigation of Optimal Vehicle Maneuvers for Different Road Conditions Bj¨orn Olofsson Lund, Sweden, firstname.lastname@control.lth.se. Department of Electrical Engineering, Link

18

Optimization of well rates under gas coning conditions  

E-Print Network [OSTI]

production rates under gas caning conditions. This new method applies to an oil reservoir overlain by a large gas cap containing multiple wells. The cases consider have a limit on the maximum field production rate for both oil and gas. It was found... that the optimal p~ion rates are achieved when Eq. 1 is satisfied for any pair of wells i and j: ) I = constant i = 1, . . . , n dqo This condition minimizes the f ield gas production rate when the maximum field production rate for oil is met, and maximizes...

Urbanczyk, Christopher Henry

2012-06-07T23:59:59.000Z

19

THE CHOICE OF OPTIMAL STRUCTURE OF ARTIFICIAL NEURAL NETWORK CLASSIFIER INTENDED FOR CLASSIFICATION OF WELDING FLAWS  

SciTech Connect (OSTI)

Nondestructive testing and evaluation are under continuous development. Currently researches are concentrated on three main topics: advancement of existing methods, introduction of novel methods and development of artificial intelligent systems for automatic defect recognition (ADR). Automatic defect classification algorithm comprises of two main tasks: creating a defect database and preparing a defect classifier. Here, the database was built using defect features that describe all geometrical and texture properties of the defect. Almost twenty carefully selected features calculated for flaws extracted from real radiograms were used. The radiograms were obtained from shipbuilding industry and they were verified by qualified operator. Two weld defect's classifiers based on artificial neural networks were proposed and compared. First model consisted of one neural network model, where each output neuron corresponded to different defect group. The second model contained five neural networks. Each neural network had one neuron on output and was responsible for detection of defects from one group. In order to evaluate the effectiveness of the neural networks classifiers, the mean square errors were calculated for test radiograms and compared.

Sikora, R.; Chady, T.; Baniukiewicz, P.; Caryk, M.; Piekarczyk, B. [West Pomeranian University of Technology in Szczecin, Department of Electrical Engineering, 70-313 Szczecin (Poland)

2010-02-22T23:59:59.000Z

20

Correct conditions for heat treatment of butt welded oil drilling pipes  

Science Journals Connector (OSTI)

The application of optimum normalization conditions decreases the hardness and increases the impact strength of drilling pipes used in geological survey work by 100% and that of oil drilling pipes by 25–30%, the ...

F. N. Tavadze; Z. G. Napetvaridze

1965-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

22

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

23

Necessary and Sufficient Conditions for Success of the Metropolis Algorithm for Optimization  

E-Print Network [OSTI]

Necessary and Sufficient Conditions for Success of the Metropolis Algorithm for Optimization, or in other words, necessary and sufficient conditions, for the success of the algorithm, both.e., necessary and sufficient conditions) for the success of the Metropolis algorithm for optimization. As our

Biswas, Somenath

24

Optimization Online - Sufficient Conditions for Low-rank Matrix ...  

E-Print Network [OSTI]

Jun 15, 2011 ... This class of optimization problems is $NP$-hard and a popular approach replaces the rank function with the nuclear norm of the matrix ...

Lingchen Kong

2011-06-15T23:59:59.000Z

25

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

26

Gasification of waste rigid polyurethane foam: optimizing operational conditions  

Science Journals Connector (OSTI)

The influence of temperature and catalyst type on production of combustible gas during the air gasification of waste rigid polyurethane foam has been...16 (43...) of three parameters was employed to optimize the...

Xiaoya Guo; Lixin Wang; Shouguang Li…

2014-07-01T23:59:59.000Z

27

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

28

Optimization and Scale-up of Antibody Purification Conditions by Hydrophobic  

E-Print Network [OSTI]

Optimization and Scale-up of Antibody Purification Conditions by Hydrophobic Charge Induction #12;Optimization and Scale-up of Antibody Purification Conditions by HCIC on MEP HHyyppeerr was regenerated using approximately 5 column volumes of 1 M NaOH. Small-scale runs were performed on an Ã?KTA

Lebendiker, Mario

29

Conditional Nonlinear Optimal Perturbations: Adjoint-Free Calculation Method and Preliminary Test  

Science Journals Connector (OSTI)

An ensemble-based approach is proposed to obtain conditional nonlinear optimal perturbation (CNOP), which is a natural extension of linear singular vector to a nonlinear regime. The new approach avoids the use of adjoint technique during ...

Bin Wang; Xiaowei Tan

2010-04-01T23:59:59.000Z

30

Optimization of Mobile Phase Conditions for TLC Methods Used in Pharmaceutical Analyses  

Science Journals Connector (OSTI)

......point," describing a fixed set of chromatographic parameters. Three-point diagrams allow mobile phase optimization to pro ceed quickly, and they build on the typical characteristics of TLC. A wide range of conditions are easily covered with this technique......

Samuel J. Costanzo

1997-04-01T23:59:59.000Z

31

Model-Based Optimal Sensor Network Design for Condition Monitoring in an IGCC Plant  

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

Optimal Sensor Network Optimal Sensor Network Design for Condition Monitoring in an IGCC Plant Background The U.S. Department of Energy's National Energy Technology Laboratory (NETL) develops affordable and clean energy from coal and other fossil fuels to secure a sustainable energy economy. To further this mission, NETL funds research and development of advanced sensor and control technologies that can function under the extreme operating conditions often found in advanced power systems,

32

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

33

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

34

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

35

Influence of boundary conditions and plate geometries on buckling optimization of symmetric laminate plates  

SciTech Connect (OSTI)

The buckling resistance of symmetrically laminated plates with a given material system and subjected to uniaxial compression is maximized with respect to fiber orientations by using a sequential linear programming method together with a simple move-limit strategy. Significant influence of plate thicknesses, aspect ratios, central circular cutouts and end conditions on the optimal fiber orientations and the associated optimal buckling loads of symmetrically laminated plates has been shown through this investigation.

Hu, H.T. [National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Civil Engineering

1995-12-31T23:59:59.000Z

36

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.

37

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.

38

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

39

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

40

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

Note: This page contains sample records for the topic "optimize welding conditions" 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

Optimization of experimental conditions for recovery of coking coal fines by oil agglomeration technique  

Science Journals Connector (OSTI)

The significance of coking coal in the metallurgical sector as well as the meager coking coal reserves across the globe increase the necessity to recover coking coal fines from the fine coking coal slurries generated from coal preparation and utilization activities. Oil agglomeration studies were carried out by varying the experimental conditions for maximum recovery of coking coal fines i.e., yield of the agglomerates. The various operational parameters studied were oil dosage, agitation speed, agglomeration time and pulp density. By using Taguchi experimental design, oil dosage (20%), agitation speed (1100 rpm), agglomeration time (3 min) and pulp density (4.5%) were identified as the optimized conditions. A confirmation experiment has also been carried out at the optimized conditions. The percentage contribution of each parameter on agglomerate yield was analyzed by adopting analysis of variance (ANOVA) statistical method as well as multiple linear regression analysis. The order of influence of the parameters on the agglomerate yield is of the following order: pulp density > oil dosage > agitation speed > agglomeration time. A mathematical model was developed to fit the set of experimental conditions with the yield obtained at each test run and also at the optimized conditions. The experimentally obtained yield was compared with the predicted yield of the model and the results indicate a maximum error of 5% between the two. A maximum yield of 90.42% predicted at the optimized conditions appeared to be in close agreement with the experimental yield thus indicating the accuracy of the model in predicting the results.

G.H.V.C. Chary; M.G. Dastidar

2010-01-01T23:59:59.000Z

42

Model Based Optimal Sensor Network Design for Condition Monitoring in an IGCC Plant  

SciTech Connect (OSTI)

This report summarizes the achievements and final results of this program. The objective of this program is to develop a general model-based sensor network design methodology and tools to address key issues in the design of an optimal sensor network configuration: the type, location and number of sensors used in a network, for online condition monitoring. In particular, the focus in this work is to develop software tools for optimal sensor placement (OSP) and use these tools to design optimal sensor network configuration for online condition monitoring of gasifier refractory wear and radiant syngas cooler (RSC) fouling. The methodology developed will be applicable to sensing system design for online condition monitoring for broad range of applications. The overall approach consists of (i) defining condition monitoring requirement in terms of OSP and mapping these requirements in mathematical terms for OSP algorithm, (ii) analyzing trade-off of alternate OSP algorithms, down selecting the most relevant ones and developing them for IGCC applications (iii) enhancing the gasifier and RSC models as required by OSP algorithms, (iv) applying the developed OSP algorithm to design the optimal sensor network required for the condition monitoring of an IGCC gasifier refractory and RSC fouling. Two key requirements for OSP for condition monitoring are desired precision for the monitoring variables (e.g. refractory wear) and reliability of the proposed sensor network in the presence of expected sensor failures. The OSP problem is naturally posed within a Kalman filtering approach as an integer programming problem where the key requirements of precision and reliability are imposed as constraints. The optimization is performed over the overall network cost. Based on extensive literature survey two formulations were identified as being relevant to OSP for condition monitoring; one based on LMI formulation and the other being standard INLP formulation. Various algorithms to solve these two formulations were developed and validated. For a given OSP problem the computation efficiency largely depends on the “size” of the problem. Initially a simplified 1-D gasifier model assuming axial and azimuthal symmetry was used to test out various OSP algorithms. Finally these algorithms were used to design the optimal sensor network for condition monitoring of IGCC gasifier refractory wear and RSC fouling. The sensors type and locations obtained as solution to the OSP problem were validated using model based sensing approach. The OSP algorithm has been developed in a modular form and has been packaged as a software tool for OSP design where a designer can explore various OSP design algorithm is a user friendly way. The OSP software tool is implemented in Matlab/Simulink© in-house. The tool also uses few optimization routines that are freely available on World Wide Web. In addition a modular Extended Kalman Filter (EKF) block has also been developed in Matlab/Simulink© which can be utilized for model based sensing of important process variables that are not directly measured through combining the online sensors with model based estimation once the hardware sensor and their locations has been finalized. The OSP algorithm details and the results of applying these algorithms to obtain optimal sensor location for condition monitoring of gasifier refractory wear and RSC fouling profile are summarized in this final report.

Kumar, Rajeeva; Kumar, Aditya; Dai, Dan; Seenumani, Gayathri; Down, John; Lopez, Rodrigo

2012-12-31T23:59:59.000Z

43

Response Surface Methodology: An Extensive Potential to Optimize in vivo Photodynamic Therapy Conditions  

SciTech Connect (OSTI)

Purpose: Photodynamic therapy (PDT) is based on the interaction of a photosensitizing (PS) agent, light, and oxygen. Few new PS agents are being developed to the in vivo stage, partly because of the difficulty in finding the right treatment conditions. Response surface methodology, an empirical modeling approach based on data resulting from a set of designed experiments, was suggested as a rational solution with which to select in vivo PDT conditions by using a new peptide-conjugated PS targeting agent, neuropilin-1. Methods and Materials: A Doehlert experimental design was selected to model effects and interactions of the PS dose, fluence, and fluence rate on the growth of U87 human malignant glioma cell xenografts in nude mice, using a fixed drug-light interval. All experimental results were computed by Nemrod-W software and Matlab. Results: Intrinsic diameter growth rate, a tumor growth parameter independent of the initial volume of the tumor, was selected as the response variable and was compared to tumor growth delay and relative tumor volumes. With only 13 experimental conditions tested, an optimal PDT condition was selected (PS agent dose, 2.80 mg/kg; fluence, 120 J/cm{sup 2}; fluence rate, 85 mW/cm{sup 2}). Treatment of glioma-bearing mice with the peptide-conjugated PS agent, followed by the optimized PDT condition showed a statistically significant improvement in delaying tumor growth compared with animals who received the PDT with the nonconjugated PS agent. Conclusions: Response surface methodology appears to be a useful experimental approach for rapid testing of different treatment conditions and determination of optimal values of PDT factors for any PS agent.

Tirand, Loraine [Centre de Recherche en Automatique de Nancy (CRAN), Nancy-University, CNRS, Centre Alexis Vautrin (CAV), Vandoeuvre-les-Nancy (France); Bastogne, Thierry [Centre de Recherche en Automatique de Nancy (CRAN), Nancy-University, CNRS, Centre Alexis Vautrin (CAV), Vandoeuvre-les-Nancy (France) and GDR 3049 Medicaments Photoactivables-Photochimiotherapie (PHOTOMED); Bechet, Denise M.Sc. [Centre de Recherche en Automatique de Nancy (CRAN), Nancy-University, CNRS, Centre Alexis Vautrin (CAV), Vandoeuvre-les-Nancy (France); Linder, Michel [Laboratoire de Sciences et Genie Alimentaires (LSGA), Ecole Nationale Superieure d'Agronomie et des Industries Alimentaires-Institut National Polytechnique de Lorraine (ENSAIA-INPL), Nancy-University, Vandoeuvre-les-Nancy, Nancy (France); Thomas, Noemie [Centre de Recherche en Automatique de Nancy (CRAN), Nancy-University, CNRS, Centre Alexis Vautrin (CAV), Vandoeuvre-les-Nancy (France); Frochot, Celine [Departement de Chimie Physique de Reactions (DCPR), Nancy-University, CNRS, Nancy (France) and GDR 3049 Medicaments Photoactivables-Photochimiotherapie (PHOTOMED); Guillemin, Francois [Centre de Recherche en Automatique de Nancy (CRAN), Nancy-University, CNRS, Centre Alexis Vautrin (CAV), Vandoeuvre-les-Nancy (France) and GDR 3049 Medicaments Photoactivables-Photochimiotherapie (PHOTOMED); Barberi-Heyob, Muriel [Centre de Recherche en Automatique de Nancy (CRAN), Nancy-University, CNRS, Centre Alexis Vautrin (CAV), Vandoeuvre-les-Nancy (France) and GDR 3049 Medicaments Photoactivables-Photochimiotherapie (PHOTOMED)], E-mail: m.barberi@nancy.fnclcc.fr

2009-09-01T23:59:59.000Z

44

Optimal Deployment of Thermal Energy Storage under Diverse Economic and Climate Conditions  

SciTech Connect (OSTI)

This paper presents an investigation of the economic benefit of thermal energy storage (TES) for cooling, across a range of economic and climate conditions. Chilled water TES systems are simulated for a large office building in four distinct locations, Miami in the U.S.; Lisbon, Portugal; Shanghai, China; and Mumbai, India. Optimal system size and operating schedules are determined using the optimization model DER-CAM, such that total cost, including electricity and amortized capital costs are minimized. The economic impacts of each optimized TES system is then compared to systems sized using a simple heuristic method, which bases system size as fraction (50percent and 100percent) of total on-peak summer cooling loads. Results indicate that TES systems of all sizes can be effective in reducing annual electricity costs (5percent-15percent) and peak electricity consumption (13percent-33percent). The investigation also indentifies a number of criteria which drive TES investment, including low capital costs, electricity tariffs with high power demand charges and prolonged cooling seasons. In locations where these drivers clearly exist, the heuristically sized systems capture much of the value of optimally sized systems; between 60percent and 100percent in terms of net present value. However, in instances where these drivers are less pronounced, the heuristic tends to oversize systems, and optimization becomes crucial to ensure economically beneficial deployment of TES, increasing the net present value of heuristically sized systems by as much as 10 times in some instances.

DeForest, Nicolas; Mendes, Goncalo; Stadler, Michael; Feng, Wei; Lai, Judy; Marnay, Chris

2014-04-15T23:59:59.000Z

45

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

46

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.

47

Optimal conditions for shock ignition of scaled cryogenic deuterium-tritium targets  

SciTech Connect (OSTI)

Within the framework of the shock-ignition (SI) scheme, ignition conditions are reached following the separation of the compression and heating phases. First, the shell is compressed at a sub-ignition implosion velocity; then an intense laser spike is launched at the end of the main drive, leading to the propagation of a strong shock through the precompressed fuel. The minimal laser energy required for ignition of scaled deuterium-tritium (DT) targets is assessed by calculations. A semi-empiric model describing the ignitor shock generation and propagation in the fuel assembly is defined. The minimal power needed in the laser spike pulse to achieve ignition is derived from the hydrodynamic model. Optimal conditions for ignition of scaled targets are explored in terms of laser intensity, shell-implosion velocity, and target scale range for the SI process. Curves of minimal laser requirements for ignition are plotted in the energy-power diagram. The most economic and reliable conditions for ignition of a millimeter DT target are observed in the 240- to 320-km/s implosion velocity range and for the peak laser intensity ranging from {approx}2 Multiplication-Sign 10{sup 15} W/cm{sup 2} up to 5 Multiplication-Sign 10{sup 15} W/cm{sup 2}. These optimal conditions correspond to shock-ignited targets for a laser energy of {approx}250 kJ and a laser power of 100 to 200 TW. Large, self-ignited targets are particularly attractive by offering ignition at a lower implosion velocity and a reduced laser intensity than for conventional ignition. The SI scheme allows for the compression and heating phases of the high power laser energy research facility target to be performed at a peak laser intensity below 10{sup 16} W/cm{sup 2}. A better control of parametric and hydrodynamic instabilities within the SI scheme sets it as an optimal and reliable approach to attain ignition of large targets.

Lafon, M. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); University of Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 33405 Talence (France); Ribeyre, X.; Schurtz, G. [University of Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 33405 Talence (France)

2013-02-15T23:59:59.000Z

48

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 20 mm 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

49

Inverse Prediction and Optimization of Flow Control Conditions for Confined Spaces using a CFD-Based Genetic Algorithm  

E-Print Network [OSTI]

temperature and velocity. In order to identify the best flow control conditions, conventional approach function to optimize the inlet boundary conditions (e.g., supply velocity, temperature, and angle of critical flow control conditions such as flow inlet temperature, velocity and angle. In order to identify

Chen, Qingyan "Yan"

50

Optimization of graphene dry etching conditions via combined microscopic and spectroscopic analysis  

SciTech Connect (OSTI)

Single-layer graphene structures and devices are commonly defined using reactive ion etching and plasma etching with O{sub 2} or Ar as the gaseous etchants. Although optical microscopy and Raman spectroscopy are widely used to determine the appropriate duration of dry etching, additional characterization with atomic force microscopy (AFM) reveals that residual graphene and/or etching byproducts persist beyond the point where the aforementioned methods suggest complete graphene etching. Recognizing that incomplete etching may have deleterious effects on devices and/or downstream processing, AFM characterization is used here to determine optimal etching conditions that eliminate graphene dry etching residues.

Prado, Mariana C. [Departamento de Fisica, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901 Belo Horizonte (Brazil)] [Departamento de Fisica, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901 Belo Horizonte (Brazil); Jariwala, Deep [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States)] [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Marks, Tobin J.; Hersam, Mark C. [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States) [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States)

2013-05-13T23:59:59.000Z

51

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

52

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

53

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

54

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

55

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

56

Optimization of direct conversion of wet algae to biodiesel under supercritical methanol conditions  

Science Journals Connector (OSTI)

This study demonstrated a one-step process for direct liquefaction and conversion of wet algal biomass containing about 90% of water to biodiesel under supercritical methanol conditions. This one-step process enables simultaneous extraction and transesterification of wet algal biomass. The process conditions are milder than those required for pyrolysis and prevent the formation of by-products. In the proposed process, fatty acid methyl esters (FAMEs) can be produced from polar phospholipids, free fatty acids, and triglycerides. A response surface methodology (RSM) was used to analyze the influence of the three process variables, namely, the wet algae to methanol (wt./vol.) ratio, the reaction temperature, and the reaction time, on the \\{FAMEs\\} conversion. Algal biodiesel samples were analyzed by ATR-FTIR and GC–MS. Based on the experimental analysis and RSM study, optimal conditions for this process are reported as: wet algae to methanol (wt./vol.) ratio of around 1:9, reaction temperature and time of about 255 °C, and 25 min respectively. This single-step process can potentially be an energy efficient and economical route for algal biodiesel production.

Prafulla D. Patil; Veera Gnaneswar Gude; Aravind Mannarswamy; Shuguang Deng; Peter Cooke; Stuart Munson-McGee; Isaac Rhodes; Pete Lammers; Nagamany Nirmalakhandan

2011-01-01T23:59:59.000Z

57

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

58

Exploring High-Dimensional Data Space: Identifying Optimal Process Conditions in Photovoltaics: Preprint  

SciTech Connect (OSTI)

We demonstrate how advanced exploratory data analysis coupled to data-mining techniques can be used to scrutinize the high-dimensional data space of photovoltaics in the context of thin films of Al-doped ZnO (AZO), which are essential materials as a transparent conducting oxide (TCO) layer in CuInxGa1-xSe2 (CIGS) solar cells. AZO data space, wherein each sample is synthesized from a different process history and assessed with various characterizations, is transformed, reorganized, and visualized in order to extract optimal process conditions. The data-analysis methods used include parallel coordinates, diffusion maps, and hierarchical agglomerative clustering algorithms combined with diffusion map embedding.

Suh, C.; Glynn, S.; Scharf, J.; Contreras, M. A.; Noufi, R.; Jones, W. B.; Biagioni, D.

2011-07-01T23:59:59.000Z

59

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

60

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

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

62

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...

63

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

64

Free Flow Energy (TRL 1 2 3 Component)- Design and Development of a Cross-Platform Submersible Generator Optimized for the Conditions of Current Energy Conversion  

Broader source: Energy.gov [DOE]

Free Flow Energy (TRL 1 2 3 Component) - Design and Development of a Cross-Platform Submersible Generator Optimized for the Conditions of Current Energy Conversion

65

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

66

Application of Genetic Algorithm to Optimal Design of Central Air-Conditioning Water System  

E-Print Network [OSTI]

network analysis ? Proceedings 3rd Hydro informatics Conference Of the International Association for Hydraulic Research, Copenhagen, Denmark, 1998:57-62. [7] R. Simpson, L. J. Murphy, G. C. Dandy. Pipe Network Optimization Using Genetic Algorithms...

Feng, X.; Zou, Y.; Long, W.

2006-01-01T23:59:59.000Z

67

Optimal Deployment of Thermal Energy Storage under Diverse Economic and Climate Conditions  

E-Print Network [OSTI]

solar heat gain coefficient (SHGC) U-factor Walls W/m K U-m K U-factor Windows W/m K SHGC 3.2. DER-CAM Optimization In

DeForest, Nicolas

2014-01-01T23:59:59.000Z

68

Optimization of Fuel Cell System Operating Conditions for Fuel Cell Vehicles  

E-Print Network [OSTI]

to achieve stable system operation and maximum fuel economy.optimizing the fuel cell system operation and the sizing ofoptimize the fuel cell system operation over the full load

Zhao, Hengbing; Burke, Andy

2008-01-01T23:59:59.000Z

69

Monte Carlo study for optimal conditions in single-shot imaging with femtosecond x-ray laser pulses  

SciTech Connect (OSTI)

Intense x-ray pulses from x-ray free electron lasers (XFELs) enable the unveiling of atomic structure in material and biological specimens via ultrafast single-shot exposures. As the radiation is intense enough to destroy the sample, a new sample must be provided for each x-ray pulse. These single-particle delivery schemes require careful optimization, though systematic study to find such optimal conditions is still lacking. We have investigated two major single-particle delivery methods: particle injection as flying objects and membrane-mount as fixed targets. The optimal experimental parameters were searched for via Monte Carlo simulations to discover that the maximum single-particle hit rate achievable is close to 40%.

Park, Jaehyun; Ishikawa, Tetsuya; Song, Changyong [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan)] [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Joti, Yasumasa [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)] [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

2013-12-23T23:59:59.000Z

70

Optimization of a solar powered absorption cycle under Abu Dhabi's weather conditions  

SciTech Connect (OSTI)

In order for the solar absorption air conditioners to become a real alternative to the conventional vapour compression systems, their performance has to be improved and their total cost has to be reduced. A solar powered absorption cycle is modeled using the Transient System Simulation (TRNSYS) program and Typical Meteorological Year 2 data of Abu Dhabi. It uses evacuated tube collectors to drive a 10 kW ammonia-water absorption chiller. Firstly, the system performance and its total cost are optimized separately using single objective optimization algorithms. The design variables considered are: the collector slope, the collector mass flow rate, the collector area and the storage tank volume. The single objective optimization results show that MATLAB global optimization methods agree with the TRNSYS optimizer. Secondly, MATLAB is used to solve a multi-objective optimization problem to improve the system's performance and cost, simultaneously. The optimum designs are presented using Pareto curve and show the potential improvements of the baseline system. (author)

Al-Alili, A.; Hwang, Y.; Radermacher, R. [Department of Mechanical Engineering, University of Maryland, College Park, MD (United States); Kubo, I. [Department of Mechanical Engineering, The Petroleum Institute, Abu Dhabi (United Arab Emirates)

2010-12-15T23:59:59.000Z

71

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

72

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

73

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

74

An Integrated Platform for Engine Performance Simulations and Optimization under Diesel Conditions  

Broader source: Energy.gov [DOE]

The direct injection stochastic reactor model is capable of accurate simulation of combustion under diesel conditions and can also be used to simulate and test different fuels.

75

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

76

Combinatorial optimization model and MIP formulation for the structural analysis of conditional differential-algebraic systems  

Science Journals Connector (OSTI)

In this paper we consider the structural analysis problem for differential-algebraic systems with conditional equations. This problem consists, given a conditional differential-algebraic system, in verifying if the system is structurally nonsingular ... Keywords: Branch-and-Cut algorithm, Differential-algebraic system, Graph, Integer linear program, Matching, Structural analysis

Mathieu Lacroix; A. Ridha Mahjoub; Sébastien Martin

2011-09-01T23:59:59.000Z

77

Optimization of operating conditions for steam turbine using an artificial neural network inverse  

Science Journals Connector (OSTI)

Abstract The useful life (UL) of the failure assessment in blades of steam turbines is optimized using the artificial intelligence. The objective of this paper is to develop an integrated approach using artificial neural network inverse (ANNi) coupling with a Nelder Mead optimization method to estimate the resonance stress when the UL of the blades is required. The proposed method \\{ANNi\\} is a new tool which inverts the artificial neural network (ANN). Firstly, It is necessary to build the artificial neural network (ANN) that simulates the output parameter (UL). ANN's model is constituted of feedforward network with one hidden layer to calculate the output of the process when input parameters are well known, then inverting ANN. The \\{ANNi\\} could be used as a tool to estimate the optimal unknown parameter required (resonance stress). Very low percentage of error and short computing time are precise and efficient, make this methodology (ANNi) attractive to be applied for control on line the UL of the system and constitutes a very promising framework for finding set of “good solutions”.

Y.El. Hamzaoui; J.A. Rodríguez; J.A. Hernández; Victor Salazar

2015-01-01T23:59:59.000Z

78

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

79

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

80

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

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

82

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

83

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

84

Optimization of the Fin Heat Pipe for Ventilating and Air Conditioning with a Genetic Algorithm  

E-Print Network [OSTI]

conservation, and it is urgent. At the same time, the energy consumption about air-conditioning of buildings continues to increase and the new wind energy accounts for 4%~12% of the buildings total energy consumption [1]. A heat recovery system for air...

Qian, J.; Sun, D.; Li, G.

2006-01-01T23:59:59.000Z

85

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

86

Plasma treatment of bulk niobium surface for superconducting rf cavities: Optimization of the experimental conditions on flat samples  

SciTech Connect (OSTI)

Accelerator performance, in particular the average accelerating field and the cavity quality factor, depends on the physical and chemical characteristics of the superconducting radio-frequency (SRF) cavity surface. Plasma based surface modification provides an excellent opportunity to eliminate nonsuperconductive pollutants in the penetration depth region and to remove the mechanically damaged surface layer, which improves the surface roughness. Here we show that the plasma treatment of bulk niobium (Nb) presents an alternative surface preparation method to the commonly used buffered chemical polishing and electropolishing methods. We have optimized the experimental conditions in the microwave glow discharge system and their influence on the Nb removal rate on flat samples. We have achieved an etching rate of 1.7???m/min using only 3% chlorine in the reactive mixture. Combining a fast etching step with a moderate one, we have improved the surface roughness without exposing the sample surface to the environment. We intend to apply the optimized experimental conditions to the preparation of single cell cavities, pursuing the improvement of their rf performance.

M. Raskovic, J. Upadhyay, L. Vuskovic, S. Popovic, A-M. Valente-Feliciano, L. Phillips

2010-11-01T23:59:59.000Z

87

Plasma treatment of bulk niobium surface for superconducting rf cavities: Optimization of the experimental conditions on flat samples  

SciTech Connect (OSTI)

Accelerator performance, in particular the average accelerating field and the cavity quality factor, depends on the physical and chemical characteristics of the superconducting radio-frequency (SRF) cavity surface. Plasma based surface modification provides an excellent opportunity to eliminate nonsuperconductive pollutants in the penetration depth region and to remove the mechanically damaged surface layer, which improves the surface roughness. Here we show that the plasma treatment of bulk niobium (Nb) presents an alternative surface preparation method to the commonly used buffered chemical polishing and electropolishing methods. We have optimized the experimental conditions in the microwave glow discharge system and their influence on the Nb removal rate on flat samples. We have achieved an etching rate of 1.7???m/min? using only 3% chlorine in the reactive mixture. Combining a fast etching step with a moderate one, we have improved the surface roughness without exposing the sample surface to the environment. We intend to apply the optimized experimental conditions to the preparation of single cell cavities, pursuing the improvement of their rf performance.

M. Raskovic, J. Upadhyay, L. Vuskovic, S. Popovic, A-M. Valente-Feliciano, L. Phillips

2010-11-01T23:59:59.000Z

88

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; Köhler, Bernd [Fraunhofer Institute for Nondestructive Testing, Dresden Branch (IZFP-D), Maria-Reiche-Str. 2, 01109 Dresden (Germany)

2014-02-18T23:59:59.000Z

89

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

90

Experimental and thermodynamical analyses of the diesel exhaust vortex generator heat exchanger for optimizing its operating condition  

Science Journals Connector (OSTI)

Abstract In this research, a vortex generator heat exchanger is used to recover exergy from the exhaust of an OM314 diesel engine. Twenty vortex generators with 30° angle of attack are used to increase the heat recovery as well as the low back pressure in the exhaust. The experiments are prepared for five engine loads (0, 20, 40, 60 and 80% of full load), two exhaust gases amount (50 and 100%) and four water mass flow rates (50, 40, 30 and 20 g/s). After a thermodynamical analysis on the obtained data, an optimization study based on Central Composite Design (CCD) is performed due to complex effect of engine loads and water mass flow rates on exergy recovery and irreversibility to reach the best operating condition.

M. Hatami; D.D. Ganji; M. Gorji-Bandpy

2015-01-01T23:59:59.000Z

91

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.

92

Optimization of HS-SPME analytical conditions using factorial design for trihalomethanes determination in swimming pool water samples  

Science Journals Connector (OSTI)

Abstract Trihalomethanes (THMs) are widely referred and studied as disinfection by-products (DBPs). The \\{THMs\\} that are most commonly detected are chloroform (TCM), bromodichloromethane (BDCM), chlorodibromomethane (CDBM), and bromoform (TBM). Several studies regarding the determination of \\{THMs\\} in swimming pool water and air samples have been published. This paper reviews the most recent work in this field, with a special focus on water and air sampling, sample preparation and analytical determination methods. An experimental study has been developed in order to optimize the headspace solid-phase microextraction (HS-SPME) conditions of TCM, BDCM, CDBM and TBM from water samples using a 23 factorial design. An extraction temperature of 45 °C, for 25 min, and a desorption time of 5 min were found to be the best conditions. Analysis was performed by gas chromatography with an electron capture detector (GC-ECD). The method was successfully applied to a set of 27 swimming pool water samples collected in the Oporto area (Portugal). TCM was the only THM detected with levels between 4.5 and 406.5 ?g L? 1. Four of the samples exceeded the guideline value for total \\{THMs\\} in swimming pool water (100 ?g L? 1) indicated by the Portuguese Health Authority.

Raquel Maia; Manuela Correia; Isabel M. Brás Pereira; Vitorino M. Beleza

2014-01-01T23:59:59.000Z

93

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

94

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

95

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

96

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

97

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

98

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

99

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.

100

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.

Note: This page contains sample records for the topic "optimize welding conditions" 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

Combustion of palm kernel shell in a fluidized bed: Optimization of biomass particle size and operating conditions  

Science Journals Connector (OSTI)

Abstract This work presents a study on the combustion of palm kernel shell (PKS) in a conical fluidized-bed combustor (FBC) using alumina sand as the bed material to prevent bed agglomeration. Prior to combustion experiments, a thermogravimetric analysis was performed in nitrogen and dry air to investigate the effects of biomass particle size on thermal and combustion reactivity of PKS. During the combustion tests, the biomass with different mean particle sizes (1.5 mm, 4.5 mm, 7.5 mm, and 10.5 mm) was burned at a 45 kg/h feed rate, while excess air was varied from 20% to 80%. Temperature and gas concentrations (O2, CO, CxHy as CH4, and NO) were recorded along the axial direction in the reactor as well as at stack. The experimental results indicated that the biomass particle size and excess air had substantial effects on the behavior of gaseous pollutants (CO, CxHy, and NO) in different regions inside the reactor, as well as on combustion efficiency and emissions of the conical FBC. The CO and CxHy emissions can be effectively controlled by decreasing the feedstock particle size and/or increasing excess air, whereas the NO emission can be mitigated using coarser biomass particles and/or lower excess air. A cost-based approach was applied to determine the optimal values of biomass particle size and excess air, ensuring minimum emission costs of burning the biomass in the proposed combustor. From the optimization analysis, the best combustion and emission performance of the conical FBC is achievable when burning PKS with a mean particle size of about 5 mm at excess air of 40–50%. Under these conditions, the combustor can be operated with high (99.4–99.7%) combustion efficiency, while controlling the gaseous emissions at acceptable levels. No evidence of bed agglomeration was found in this conical FBC using alumina as the bed material for the entire time period of experimental tests.

Pichet Ninduangdee; Vladimir I. Kuprianov

2014-01-01T23:59:59.000Z

102

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...

103

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

104

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

105

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

106

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

107

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

108

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

109

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

110

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

111

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

112

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

113

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

114

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...

115

Performance Optimization of a Fan System- Overcoming Impacts of Modified Design Criteria Due to Regulatory Requirements and Changed Operating Conditions  

E-Print Network [OSTI]

that was applied to address fan inefficiency. Energy savings from optimizing the system are estimated to be 338 kW, nearly half of the original measured input power of 678 kW. The project is currently being implemented and will have a payback period of less than 8...

Wroblewski, R. G.; Preis, F.; Smith, R.

116

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.

117

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

118

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

119

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

120

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

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

122

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

123

Innovative Method for Performance Inspections often save 20-30% through Optimization of Air-Conditioning and Refrigeration  

E-Print Network [OSTI]

of performance?. (Nordtest.) Esbo, Finland. 16. NT VVS 116, 1997. ?Refrigeration and heat pump equipment: Check-ups and performance data inferred from measurements under field conditions in the refrigerant system?. (Nordtest.) Esbo, Finland. ESL-IC-10...

Berglof, K.

2010-01-01T23:59:59.000Z

124

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

125

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

126

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

127

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

128

Nonlinear control and online optimization of the burn condition in ITER via heating, isotopic fueling and impurity injection  

Science Journals Connector (OSTI)

The ITER tokamak, the next experimental step toward the development of nuclear fusion reactors, will explore the burning plasma regime in which the plasma temperature is sustained mostly by fusion heating. Regulation of the fusion power through modulation of fueling and external heating sources, referred to as burn control, is one of the fundamental problems in burning plasma research. Active control will be essential for achieving and maintaining desired operating points, responding to changing power demands, and ensuring stable operation. Most existing burn control efforts use either non-model-based control techniques or designs based on linearized models. These approaches must be designed for particular operating points and break down for large perturbations. In this work, we utilize a spatially averaged (zero-dimensional) nonlinear model to synthesize a multi-variable nonlinear burn control strategy that can reject large perturbations and move between operating points. The controller uses all of the available actuation techniques in tandem to ensure good performance, even if one or more of the actuators saturate. Adaptive parameter estimation is used to improve the model parameter estimates used by the feedback controller in real-time and ensure asymptotic tracking of the desired operating point. In addition, we propose the use of a model-based online optimization algorithm to drive the system to a state that minimizes a given cost function, while respecting input and state constraints. A zero-dimensional simulation study is presented to show the performance of the adaptive control scheme and the optimization scheme with a cost function weighting the fusion power and temperature tracking errors.

Mark D Boyer; Eugenio Schuster

2014-01-01T23:59:59.000Z

129

Pessimistic Bilevel Optimization  

E-Print Network [OSTI]

We study a variant of the pessimistic bilevel optimization problem, which comprises constraints that must be satisfied for any optimal solution of a subordinate (lower-level) optimization problem. We present conditions ...

Wiesemann, Wolfram

130

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

131

Optimizing CO2 reduction conditions to increase carbon atom conversion using a Pt-RGO||Pt-TNT photoelectrochemical cell  

Science Journals Connector (OSTI)

Abstract This study aimed to determine the optimum conditions required to increase the carbon atom conversion rate in a Pt-RGO||Pt-TNT photoelectrochemical cell. The effects of Pt-RGO reduction time on CO2 conversion, voltage applied through the cell, catholyte pH, and pore size of nickel foam as a catalyst support were investigated. The conversion rate of C atoms initially increased and then decreased with increasing Pt-RGO reduction time, increasing electrolyte pH, and decreasing nickel foam pore size. Although carbon atom conversion showed sustainable growth as the applied voltage increased, the current efficiency of CO2 reduction products decreased because of enhanced proton interference when the voltage applied through the cell exceeds 2 V. A maximum carbon atom conversion rate of 1500 nmol/(cm2 h) was obtained by Pt-RGO reduction for 24 h when a 2 V voltage was applied through the cell, the catholyte pH was 8.8, and nickel foam with an average pore size of 160 ?m was used as a support. Under optimum conditions, the liquid product selectivity of CO2 reduction reached 99%. The results of the study indicate that RGO-based catalysts have potential use as blueprints for CO2 reduction.

Jun Cheng; Meng Zhang; Gai Wu; Xin Wang; Junhu Zhou; Kefa Cen

2015-01-01T23:59:59.000Z

132

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

133

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

134

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.

135

Energy consumption and optimization of internally cooled/heated liquid desiccant air-conditioning system: A case study in Hong Kong  

Science Journals Connector (OSTI)

Abstract LDAC (liquid desiccant air-conditioning system) is promising for reducing the energy consumption, and improving the indoor air quality. In this paper, the operation performance of LDAC with internally cooled/heated dehumidifier/regenerator was simulated and optimized. The cooling tower and solar collectors were employed as the cooling/heating source. Four nested iteration loops were developed and solved for system modeling. A typical commercial building in Hong Kong was selected as a case study, which air-conditioning load was obtained by Energy-plus. Results show that with the increase of solar collector area, the electricity consumption of AC (air-conditioning systems) system reduced by 11–35% in original system, but only a part of dehumidification demand was handled with liquid desiccant ventilation, which led to a low chiller COP (coefficient of performance). By adding a cooling coil for the solution entering dehumidifier, the electricity saving effectively increased to 22–47%, while the heat demand for regeneration also increased by 17%. So, a heat exchanger between water leaving regenerator and solution leaving dehumidifier was introduced. With the lower thermal requirement (reduced by 20%) and higher solar fraction (increased from 30 to 40%), the saving further increased to 29–49%, and the required collector area obviously reduced by 50–60% for the similar energy saving purpose.

Ronghui Qi; Lin Lu

2014-01-01T23:59:59.000Z

136

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

137

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

138

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

139

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

140

Optimal design and control strategies for novel combined heat and power (CHP) fuel cell systems. Part I of II, datum design conditions and approach.  

SciTech Connect (OSTI)

Energy network optimization (ENO) models identify new strategies for designing, installing, and controlling stationary combined heat and power (CHP) fuel cell systems (FCSs) with the goals of (1) minimizing electricity and heating costs for building owners and (2) reducing emissions of the primary greenhouse gas (GHG) - carbon dioxide (CO{sub 2}). A goal of this work is to employ relatively inexpensive simulation studies to discover more financially and environmentally effective approaches for installing CHP FCSs. ENO models quantify the impact of different choices made by power generation operators, FCS manufacturers, building owners, and governments with respect to two primary goals - energy cost savings for building owners and CO{sub 2} emission reductions. These types of models are crucial for identifying cost and CO{sub 2} optima for particular installations. Optimal strategies change with varying economic and environmental conditions, FCS performance, the characteristics of building demand for electricity and heat, and many other factors. ENO models evaluate both 'business-as-usual' and novel FCS operating strategies. For the scenarios examined here, relative to a base case of no FCSs installed, model results indicate that novel strategies could reduce building energy costs by 25% and CO{sub 2} emissions by 80%. Part I of II articles discusses model assumptions and methodology. Part II of II articles illustrates model results for a university campus town and generalizes these results for diverse communities.

Colella, Whitney G.

2010-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

142

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

143

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

144

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

145

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

146

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

147

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

148

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.

149

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

150

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

151

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

152

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

153

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

154

Optimization of Air Conditioning Cycling  

E-Print Network [OSTI]

Benchmark – Long Cycle .............................................................................................. 95 5.46 System Pressures and Temperatures – Valve Part Cycle Vs Benchmark – Long Cycle...

Seshadri, Swarooph

2012-10-19T23:59:59.000Z

155

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

156

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

157

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

158

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

159

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.

160

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

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

162

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

163

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

164

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

165

Optimal power flow under both normal and contingent operation conditions using the hybrid fuzzy particle swarm optimisation and Nelder-Mead algorithm (HFPSO-NM)  

Science Journals Connector (OSTI)

In this paper, we solve the optimal power flow problem using by the new hybrid fuzzy particle swarm optimisation and Nelder-Mead (NM) algorithm (HFPSO-NM). The goal of combining the NM simplex method and the particle swarm optimisation (PSO) method is ... Keywords: Fuzzy logic, HFPSO-NM, Nelder-Mead method, Optimal power flow, Particle swarm optimisation, Voltage stability

Mahmood Joorabian; Ehsan Afzalan

2014-01-01T23:59:59.000Z

166

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

167

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

168

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

169

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

170

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

171

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

172

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

173

Optimizing the Probability of Flying in High Ice Water Content Conditions in the Tropics Using a Regional-Scale Climatology of Convective Cell Properties  

Science Journals Connector (OSTI)

In this paper, statistical properties of rainfall are derived from 14 years of Tropical Rainfall Measuring Mission data to optimize the use of flight hours for the upcoming High Altitude Ice Crystals (HAIC)/High Ice Water Content (HIWC) program. ...

A. Protat; S. Rauniyar; V. V. Kumar; J. W. Strapp

2014-11-01T23:59:59.000Z

174

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

175

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

176

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...

177

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

178

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

179

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

180

Characterization of solid-phase welds between Ti-6Al-2Sn-4Zr-2Mo-0. 01Si and Ti-13. 5A1-21. 5Nb titanium aluminide  

SciTech Connect (OSTI)

Dissimilar-alloy welds have been produced between Ti-6Al-2Sn-4Zr-2Mo-0.1Si (wt.%) and Ti-13.5Al-21.5Nb (wt.%) titanium aluminide using three different solid-phase welding processes that create significantly different thermo-mechanical conditions at the weld interface. Exposure to supertransus temperatures, appreciable deformation and rapid cooling of the weld interface region during linear-friction welding promote dynamic recrystallization of beta grains and beta decomposition to fine martensitic products. In contrast, diffusion welding at temperatures below the base metal beta transus temperatures and at relatively low pressures minimizes deformation and microstructural variations in the weld interface region relative to the unaffected base metal. During capacitor-discharge resistance spot welding, extremely rapid heating of the weld interface region to near-solidus temperatures, and subsequent rapid cooling, result in the formation of a metastable, ordered-beta microstructure in the Ti-13.5ASl-21.5Nb and fine alpha-prime martensite in the Ti-6Al-2Sn-4Zr-2Mo-0.1Si.

Baeslack, W.A. III; Juhas, M.; Fraser, H.L. (Ohio State Univ., Columbus, OH (United States)); Broderick, T.F. (Wright Labs., Wright Patterson AFB, OH (United States). Materials Directorate)

1994-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

182

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

183

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

184

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

185

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

186

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

187

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

188

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

189

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

190

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

191

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

192

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

193

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.

194

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.

195

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

196

Treatment of wastewater effluents from paper-recycling plants by coagulation process and optimization of treatment conditions with response surface methodology  

Science Journals Connector (OSTI)

In the present study, a coagulation process was used to treat paper-recycling wastewater with alum coupled with poly aluminum chloride ... optimum conditions for high treatment efficiency of paper-recycling wastewater

Noushin Birjandi; Habibollah Younesi; Nader Bahramifar

2014-09-01T23:59:59.000Z

197

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 Guimarães (Portugal)

2014-05-15T23:59:59.000Z

198

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

199

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...

200

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

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

202

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

203

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

204

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

205

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

206

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...

207

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

208

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

209

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...

210

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...

211

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

212

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

213

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

214

Optimization Journals, Sites, Societies  

E-Print Network [OSTI]

Optimization Online Links. Optimization related societies. Mathematical Optimization Society · SIAM · INFORMS. Optimization related journals. Mathematical ...

215

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.

216

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].

217

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

218

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

219

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.

220

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

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

222

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

223

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

224

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

225

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

226

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

227

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

228

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

229

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

230

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

231

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

232

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

233

Air Conditioning  

Science Journals Connector (OSTI)

Air Conditioning ... CHEMISTS and engineers use air conditioning as a valuable tool in more than two hundred industries. ... Air conditioning is a tool with many facets. ...

MARGARET INGELS

1938-02-10T23:59:59.000Z

234

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

235

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

236

Optimization Neuroimaging'',  

E-Print Network [OSTI]

Canonical Ridge Analysis with Ridge Parameter Optimization F. �. Nielsen, L. K. Hansen and S. C - PLS 1 = k 0 = k optimal k k = optimal k k £ £ 0 #12; Canonical Ridge Analysis with Ridge Parameter Optimization F. �. Nielsen, L. K. Hansen and S. C. Strother The Human Brain Project, P20 MH57180 ``Spatial

Nielsen, Finn Ã?rup

237

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

238

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...

239

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

240

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 "optimize welding conditions" 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

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 Höhne; Sanjeevareddy Kolkoori…

2013-03-01T23:59:59.000Z

242

Elementary optimality conditions for nonlinear SDPs  

E-Print Network [OSTI]

Dec 6, 2010 ... We denote the feasible set of the NLSDP (1) by F1 and recall that the ... We derive a representation of T1: Let ¯x ? F1 be given and, as in ...

2010-12-06T23:59:59.000Z

243

Necessary optimality conditions in pessimistic bilevel programming  

E-Print Network [OSTI]

Jan 10, 2012 ... Employing advanced tools of variational analysis and generalized differentiation, we provide rather general frameworks ensuring the Lipschitz ...

Stephan Dempe

2012-01-10T23:59:59.000Z

244

OPTIMIZATION TOPICS LIST Revised April 2012  

E-Print Network [OSTI]

1 OPTIMIZATION TOPICS LIST Revised April 2012 For Fall 2012 and Spring 2013 we will adopt. Bertsimas and J. Tsitsiklis, Introduction to Linear Optimization, Athena Scientific, 1997 2. M. C. Ferris, O and mixed integer models · Existence of optimal solutions, optimality conditions · Branch and bound methods

Radeloff, Volker C.

245

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

246

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

247

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

248

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

249

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

250

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

251

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

252

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...

253

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...

254

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 (5–20 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

255

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

256

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

257

Optimization 1-1 Convex Optimization & Duality  

E-Print Network [OSTI]

1 Optimization 1-1 Convex Optimization & Duality EEN634, Spring 2007 BASED ON LECTURES GIVEN AT MIT and Princeton Department of ECE, UMiami Optimization 1-2 #12;2 Optimization 1-3 Optimization 1-4 #12;3 Optimization 1-5 Optimization 1-6 #12;4 Optimization 1-7 Optimization 1-8 #12;5 Optimization 1-9 Optimization 1

Fan, Xingzhe

258

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

259

Optimization Online - Optimal Design of Electrical Machines ...  

E-Print Network [OSTI]

Jun 8, 2011 ... Optimal Design of Electrical Machines: Mathematical Programming ... Science and Engineering (Multidisciplinary Design Optimization ).

Sonia Cafieri

2011-06-08T23:59:59.000Z

260

Direct optimization overly optimizes data Kazunori Yoshizawa  

E-Print Network [OSTI]

OPINION Direct optimization overly optimizes data Kazunori Yoshizawa Systematic Entomology optimization is a criterion that recognizes sequence alignment and tree search as a single epistemological optimization criterion, all data partitions are combined and optimized simultaneously along with the same tree

Yoshizawa, Kazunori

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

262

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

263

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.

264

Initial Conditions  

Science Journals Connector (OSTI)

Before we can run a transient analysis, we must find the appropriate set of initial conditions for the variables. The most important requirement of initial conditions is that they do not contradict any of the ...

Michael Tiller Ph.D.

2001-01-01T23:59:59.000Z

265

Analysis of effect of temperature gradients on surface-tension phenomena in gas-tungsten-arc welds  

SciTech Connect (OSTI)

Fluid motion directed by surface tension is considered as a contributor to heat penetration in a weld pool. The potential phenomena at the gas-liquid interface were analyzed, and the dependence of surface motion on temperature in the gas-tungsten-arc (GTA) welding process was examined. An existing heat-transfer model was used and was able to predict weld size to +- 50% of the actual value. A momentum-transfer equation was derived by considering the contribution of Lorentz force. The momentum boundary condition was developed and was able to predict the Marangoni effect. The magnitude of surface-tension-driven force is comparable to the gravitational force on one gram. An empirical approach was proposed to couple heat-transfer and momentum-transfer phenomena. A dimensional analysis identified the pertinent dimensionless groups as Reynolds, Weber, Froude, Peclet, and Power numbers and a dimensionless velocity. A simplified form of the correction was developed by combining dimensionless groups to yield a correlation with the Bond, Prandtl, and modified power numbers. Future experimental work was proposed to test the functionality of the dimensionless groups.

Lee, H.A.; Chien, P.S.J.

1982-10-01T23:59:59.000Z

266

Main conclusions of the PISC action on safe-end welds  

SciTech Connect (OSTI)

Action 3 was initiated in 1986, in the framework of the PISC 3 program, to evaluate the actual NDE capability for the structural integrity assessment of safe-ends in power plants. Applying the methodology developed in PISC 1 and PISC 2, Round-Robin Trials (RRT) were organized on the basis of test assemblies representative of BWR and PWR designs, with the objective of identifying effective examination methods, particularly for in-service inspection, and of informing subsequently Codes and Standards organizations of the outcomes. The features of the assemblies allow to evaluate the inspection performances on reactor pressure vessel safe-end welds, as well as on PWR steam Generator and source line dissimilar metal welds. The attention of the reader is drawn however on the fact that, when conclusions on the NDT capability in industrial conditions are drawn from this exercise, the validity of the comparison must be carefully verified. The following reviews briefly the organization and integrates the main outcomes of PISC Action 3. Further details can be found in the dedicated PISC reports.

Dombret, P. [AIB-Vincotte, Brussels (Belgium); Crutzen, S. [Commission of the European Communities, Ispra (Italy)

1994-12-31T23:59:59.000Z

267

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

268

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

269

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

270

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

271

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

SciTech Connect (OSTI)

The potential to save trillions of BTU’s 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

272

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

273

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

274

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

275

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

276

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

277

.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.

278

Seminar on dissimilar welds in fossil-fired boilers: proceedings. [Often ferritic and austenitic steels  

SciTech Connect (OSTI)

Failure of dissimilar metal welds (DMW) in superheater and reheater sections is a major cause of forced outage of boilers. Research and development has been in progress at several organizations throughout the world including a major project, RP 1874, sponsored by EPRI. As a result of these efforts the causes of DMW failures are now better known than before. Several viable remedies have been identified. The effects of plant operational variables on damage to the DMWs have been quantified. Methods for assessing the condition of DMWs in the field have been developed. A seminar was organized for the purpose of reviewing and consolidating all the information available relating to failure causes and remedies for the DMW failure problems. The proceedings from the seminar are presented in this report. The papers have been entered individually into EDB and ERA. (LTN)

Viswanathan, R.; Roberts, D.A. (eds.)

1985-07-01T23:59:59.000Z

279

Carver Performance and Optimization  

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

Optimization Performance and Optimization Performance Monitoring Last edited: 2012-01-09 12:31:03...

280

241-AP Tank Farm Construction Extent of Condition Review for Tank Integrity  

SciTech Connect (OSTI)

This report provides the results of an extent of condition construction history review for the 241-AP tank farm. The construction history of the 241-AP tank farm has been reviewed to identify issues similar to those experienced during tank AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank AY-102 as the comparison benchmark. In the 241-AP tank farm, the sixth double-shell tank farm constructed, tank bottom flatness, refractory material quality, post-weld stress relieving, and primary tank bottom weld rejection were improved.

Barnes, Travis J.; Gunter, Jason R.; Reeploeg, Gretchen E.

2014-04-04T23:59:59.000Z

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

282

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

283

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...

284

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

285

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

286

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...

287

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...

288

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

289

Experimental tests of irradiation-anneal-reirradiation effects on mechanical properties of RPV plate and weld materials  

SciTech Connect (OSTI)

The Charpy-V (C{sub V}) notch ductility and tension test properties of three reactor pressure vessel (RPV) steel materials were determined for the 288{degree}C (550{degree}F) irradiated (I), 288{degree}C (550{degree}F) irradiated + 454{degree}C (850{degree}F)-168 h postirradiation annealed (IA), and 288{degree}C (550{degree}F) reirradiated (IAR) conditions. Total fluences of the I condition and the IAR condition were, respectively, 3.33 {times} 10{sup 19} n/cm{sup 2} and 4.18 {times} 10{sup 19} n/cm{sup 2}, E > 1 MeV. The irradiation portion of the IAR condition represents an incremental fluence increase of 1. 05 {times} 10{sup 19} n/cm{sup 2}, E > 1 MeV, over the I-condition fluence. The materials (specimens) were supplied by the Yankee Atomic Electric Company and represented high and low nickel content plates and a high nickel, high copper content weld deposit prototypical of the Yankee-Rowe reactor vessel. The promise of the IAR method for extending the fluence tolerance of radiation-sensitive steels and welds is clearly shown by the results. The annealing treatment produced full C{sub V} upper shelf recovery and full or nearly full recovery in the C{sub V} 41 J (30 ft-lb) transition temperature. The C{sub V} transition temperature increases produced by the reirradiation exposure were 22% to 43% of the increase produced by the first cycle irradiation exposure. A somewhat greater radiation embrittlement sensitivity and a somewhat greater reirradiation embrittlement sensitivity was exhibited by the low nickel content plate than the high nickel content plate. Its high phosphorus content is believed to be responsible. The IAR-condition properties of the surface vs. interior regions of the low nickel content plate are also compared.

Hawthorne, J.R. [Materials Engineering Associates, Inc., Lanham, MD (United States)

1996-01-01T23:59:59.000Z

290

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":""}]}

291

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

292

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

293

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

294

(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

295

Multidimensional effects in optimal control analysis for nuclear reactors  

SciTech Connect (OSTI)

Physically realistic step function control rod models are shown to be unsolvable under traditional formulations of distributed parameter optimal control theory. Extensions to the theory are proposed and derived to allow these systems to be analyzed using straightforward optimality conditions. The extended theory is then applied to a xenon-iodine oscillation problem in two dimensions. The conditions of optimality are found, and analytical insights concerning the importance of the control rod tip for the optimality condition are obtained. The flux influence function is found by solving an eigenvalue problem, and the required normalization condition is found in one of the optimality conditions. The optimality and normalization conditions are solved numerically for a severe xenon transient, and the transient is stabilized by the intervention of the optimal control.

Wyss, G.D.; Alford, R.A.

1988-12-01T23:59:59.000Z

296

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

297

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

298

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

299

A quantitative determination of the conditions for hot cracking during welding for aluminum alloys  

E-Print Network [OSTI]

Memorial Institute, February 1964. 2. Savage, W. F. and Krantz, B. M. , "An Investigation of Hot Cracking in Hastelloy X, ' ~Weldin Journal, 45(51, 13s-25s (1966) . Borland, J. C. and Younger, R. N. , "Some Aspects of Cracking in Cr-Ni Austenite Steels...-T6 Alu?iinum 25 10 Typical Load-Temperature Data 26 Typical Modulus of Elasticity Verses Temperature Re1atiousI!ip fcr Aluminum Alloys 32 12 As-Received and Ai. r Cooled (T = 1125'P) 6061-T6 Specimens (100X) 37 13 Hot Cracked 6061-T6 Aluminur...

Steenbergen, James Everett

1969-01-01T23:59:59.000Z

300

Matlab-based Optimization: Optimization Toolbox  

E-Print Network [OSTI]

Matlab-based Optimization: the Optimization Toolbox Gene Cliff (AOE/ICAM - ecliff@vt.edu ) 3:00pm Engineering ICAM: Interdisciplinary Center for Applied Mathematics 1 / 37 #12;Matlab's Optimization Toolbox;Matlab's Optimization Toolbox Classifying Optimization Problems A Soup Can Example Intermezzo

Crawford, T. Daniel

Note: This page contains sample records for the topic "optimize welding conditions" 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

Fuzzy Optimality and Evolutionary Multiobjective Optimization  

E-Print Network [OSTI]

Fuzzy Optimality and Evolutionary Multiobjective Optimization M. Farina and P. Amato. Pareto optimality is someway ineffective for optimization problems with several (more than three) objectives. In fact the Pareto optimal set tends to become a wide portion of the whole design domain search

Coello, Carlos A. Coello

302

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

303

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

304

DOE Announces Webinars on High Performance Space Conditioning...  

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

of the Partnership for Home Innovation, discussing buried ducts in conditioned spaces; Jordan Dentz of Advanced Residential Integrated Energy Solutions, speaking about optimizing...

305

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

306

OPTIMIZING YOUR  

E-Print Network [OSTI]

Electric motor-driven systems are estimated to consume over half of all electricity in the United States and over 70 % of all electricity in many industrial plants. This fact sheet presents an overview of electric drive systems and highlights common ways you can improve system efficiency and reliability. By optimizing the efficiency of your motor-driven systems, you can increase productivity while saving significant amounts of energy and money.

unknown authors

307

Optimization Online - Global Optimization Submissions - 2014  

E-Print Network [OSTI]

Zhao Sun. February 2014. Global optimization on the torus, the sphere and the rotation ... RBFOpt: an open-source library for black-box optimization with costly ...

308

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

309

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

310

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.

311

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

312

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

313

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

314

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

315

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

316

Advanced Review Geometry optimization  

E-Print Network [OSTI]

Advanced Review Geometry optimization H. Bernhard Schlegel Geometry optimization is an important part of most quantum chemical calcu- lations. This article surveys methods for optimizing equilibrium geometries, lo- cating transition structures, and following reaction paths. The emphasis is on optimizations

Schlegel, H. Bernhard

317

Optimization Jason Courter  

E-Print Network [OSTI]

Optimization Jason Courter Foundations of Ecology #12;What is optimization? Maximization Minimization Optimization Natural Selection 1. Variation 2. Heritable Variation 3. Differential Reproduction #12;On Optimal use of a Patchy Environment · Robert MacArthur · Eric Pianka http

Jodice, Patrick

318

Explanatory Optimization of Protein Mass Spectrometry via Genetic Search  

E-Print Network [OSTI]

of the mass spectrometer settings that accounts for much of this success. Specifically, the conditions of Wales, Aberystwyth, Ceredigion SY23 3DD, U.K. Optimizing experimental conditions for the effective analy that little or no a priori knowledge of the optimal conditions is available. There is much current interest

Fernandez, Thomas

319

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

320

Optimization Online - Digest Archive  

E-Print Network [OSTI]

Optimization Online Digest Archive. Subscribe to the digest. ... Online is supported by the Mathematical Optmization Society. Mathematical Optimization Society.

Note: This page contains sample records for the topic "optimize welding conditions" 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

Optimization Online - Category Archive  

E-Print Network [OSTI]

Optimization Online. Browse Submissions By Area. Linear, Cone and Semidefinite ... Optimization Online is supported by the Mathematical Optmization Society.

322

Optimization Online - Coordinators  

E-Print Network [OSTI]

Optimization Online submissions are electronically handled by a team of ... OR and Management Sciences / Integer Programming / Robust Optimization ...

323

Optimization Online - Category Archive  

E-Print Network [OSTI]

Optimization Online. Browse Submissions By Area. Nonlinear Optimization. 2000 · 2001 · 2002 · 2003 · 2004 · 2005 · 2006 · 2007 · 2008 · 2009 · 2010 · 2011 ...

324

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

325

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

326

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

327

Corrosion behavior in high heat input welded heat-affected zone of Ni-free high-nitrogen Fe–18Cr–10Mn–N austenitic stainless steel  

SciTech Connect (OSTI)

The pitting corrosion and interphase corrosion behaviors in high heat input welded heat-affected zone (HAZ) of a metastable high-nitrogen Fe–18Cr–10Mn–N austenitic stainless steel were explored through electrochemical tests. The HAZs were simulated using Gleeble simulator with high heat input welding condition of 300 kJ/cm and the peak temperature of the HAZs was changed from 1200 °C to 1350 °C, aiming to examine the effect of ?-ferrite formation on corrosion behavior. The electrochemical test results show that both pitting corrosion resistance and interphase corrosion resistance were seriously deteriorated by ?-ferrite formation in the HAZ and their aspects were different with increasing ?-ferrite fraction. The pitting corrosion resistance was decreased by the formation of Cr-depleted zone along ?-ferrite/austenite (?) interphase resulting from ?-ferrite formation; however it didn't depend on ?-ferrite fraction. The interphase corrosion resistance depends on the total amount of Cr-depleted zone as well as ferrite area and thus continuously decreased with increasing ?-ferrite fraction. The different effects of ?-ferrite fraction on pitting corrosion and interphase corrosion were carefully discussed in terms of alloying elements partitioning in the HAZ based on thermodynamic consideration. - Highlights: • Corrosion behavior in the weld HAZ of high-nitrogen austenitic alloy was studied. • Cr{sub 2}N particle was not precipitated in high heat input welded HAZ of tested alloy. • Pitting corrosion and interphase corrosion show a different behavior. • Pitting corrosion resistance was affected by whether or not ?-ferrite forms. • Interphase corrosion resistance was affected by the total amount of ?-ferrite.

Moon, Joonoh, E-mail: mjo99@kims.re.kr; Ha, Heon-Young; Lee, Tae-Ho

2013-08-15T23:59:59.000Z

328

Derivative Free Optimization Methods for Optimizing Stirrer ...  

E-Print Network [OSTI]

It also gives a comparison of the two optimization algorithms. Key words: Energy, Numerical Optimization, Derivative-Free Optimization,. Computational Fluid ... numerical simulations are needed for the computation of the fluid flow inside the stirrer for ..... Optimization Methods and Software, 20 (2005) 493-508. [6] A. R. Conn ...

2007-02-01T23:59:59.000Z

329

Optimization Online - Nonlinear Optimization Submissions - 2014  

E-Print Network [OSTI]

Unconstrained Optimization Generalized Inexact Proximal Algorithms: Habit's/ Routine's Formation with Resistance to Change, following Worthwhile Changes

330

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

331

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

332

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

333

How to Solve a Semi-infinite Optimization Problem  

E-Print Network [OSTI]

Mar 27, 2012 ... optimality conditions and the design of numerical methods rely. Section 4 ...... [9] B. Bhattacharjee, W.H. Green Jr., P.I. Barton, Interval meth-.

2012-03-27T23:59:59.000Z

334

Gas Network Optimization: A comparison of Piecewise Linear Models  

E-Print Network [OSTI]

Oct 4, 2014 ... ... and advanced MILP formulations for the gas network optimization in dynamic or in steady-state conditions. ... Search, Browse the Repository.

CARLOS M. CORREA-POSADA

2014-10-04T23:59:59.000Z

335

Optimized Triple-Junction Solar Cells Using Inverted Metamorphic Approach (Presentation)  

SciTech Connect (OSTI)

Record efficiencies with triple-junction inverted metamorphic designs, modeling useful to optimize, and consider operating conditions before choosing design.

Geisz, J. F.

2008-11-01T23:59:59.000Z

336

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

337

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

338

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

339

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

340

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

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

342

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

343

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

344

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

345

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

346

Industrial Optimization Compact Course  

E-Print Network [OSTI]

Industrial Optimization Compact Course and Challenge Workshop Optimization plays a crucial role of the processes are typically nonlinear and dyna- mic. Thus, complex dynamic optimization or optimal control in industrial optimization. February 17­20, 2014 ·9.00­17.00 IWR ·Im Neuenheimer Feld 368 ·69120 Heidelberg www

Kirches, Christian

347

The optimization problem Genetic Algorithm  

E-Print Network [OSTI]

The optimization problem Genetic Algorithm Particle Swarm Optimization Experimental results for time-power optimization META, October 27-31, 2014 1 / 25 #12;The optimization problem Genetic Algorithm Particle Swarm Optimization Experimental results Conclusions Time and energy optimization Traditionally

Giménez, Domingo

348

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

349

Shrinking Procedures and Optimal Algorithms  

E-Print Network [OSTI]

Jun 18, 2012 ... Optimal Stochastic Approximation Algorithms for Strongly Convex Stochastic Composite Optimization, II: Shrinking Procedures and Optimal ...

Saeed Ghadimi

2012-06-18T23:59:59.000Z

350

Optimization Online - Multistage Adaptive Robust Optimization for ...  

E-Print Network [OSTI]

Sep 5, 2014 ... ... with the increasing penetration of wind and solar power generation has ... Keywords: Electric energy systems, multistage robust optimization, ... Multistage Adaptive Robust Optimization for the Unit Commitment Problem.

Alvaro Lorca

2014-09-05T23:59:59.000Z

351

COMBINATORIAL OPTIMIZATION IN TELECOMMUNICATIONS  

E-Print Network [OSTI]

COMBINATORIAL OPTIMIZATION IN TELECOMMUNICATIONS MAURICIO G. C. RESENDE Abstract. Combinatorial to optimally design a SONET ring network. The last problem comes up when planning a global telecommunications network. 1. Introduction Combinatorial optimization problems are abundant in the telecommunications

Resende, Mauricio G. C.

352

Essays on optimal taxation  

E-Print Network [OSTI]

This thesis studies the optimal income tax scheme in four different settings. Chapter 1 focuses on the implications of lack of commitment for the optimal labor and capital income tax rates. It finds that it is optimal to ...

Reis, Catarina (Catarina Luis Monteiro dos)

2007-01-01T23:59:59.000Z

353

Compiler Optimization Jordan Bradshaw  

E-Print Network [OSTI]

Compiler Optimization Jordan Bradshaw #12;Outline Overview Goals and Considerations ­ Scope. 346- 352. Print. "Compiler Optimization." Wikipedia. Wikimedia Foundation, 25 04 2010. Web. 25 Apr 2010. #12;Compiler Optimization Goals: ­ Speed

Valtorta, Marco

354

Optimization Online - Certificates of Optimality and Sensitivity ...  

E-Print Network [OSTI]

Dec 9, 2014 ... Certificates of Optimality and Sensitivity Analysis using Generalized Subadditive Generator Functions: A test study on Knapsack Problems.

Babak Moazzez

2014-12-09T23:59:59.000Z

355

Optimization Online - Semidefinite Optimization Approaches to ...  

E-Print Network [OSTI]

Sep 16, 2014 ... Semidefinite Optimization Approaches to Applications in Facility ... Category 2: Applications -- OR and Management Sciences (Transportation ).

Philipp Hungerlaender

2014-09-16T23:59:59.000Z

356

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,

357

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:...

358

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

359

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...

360

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

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

362

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...

363

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

364

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

365

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

366

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...

367

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

368

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

369

Optimization Online - Digest  

E-Print Network [OSTI]

Complete the form below to subscribe to the free Optimization Online Digest. ... Type your e-mail address to unsubscribe from the Optimization Online Digest.

370

PDSF Performance and Optimization  

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

Optimization Performance and Optimization Running Jobs Efficiently This page defines job efficiency and how to measure the efficiency of your jobs. Read More PDSF IO Monitoring...

371

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 8.85 wt.% hydrogen at 77 K 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

372

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

373

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

374

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

375

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

376

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

377

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

378

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

379

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

380

Kernel Optimizations in SORD  

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

Kernel Optimizations in SORD Kernel Optimizations in SORD earthquake dynamic rupture code Geoffrey P. Ely Leadership Computing Facility Argonne National Laboratory MiraCon March 7, 2013 S C E C an NSF+USGS center Acknowledgements Tareq Malas King Abdullah Univ. of Science & Technology Vitali Morozov Argonne Leadership Computing Facility Karen Magerlein IBM Watson Research Center Simulation Scale Outer length scale: ~500km Inner length scale: ~50m Mesh points: ~10 12 Spatial Derivatives f (⇠) = n X ↵, , =0 N ↵ (⇠)f ↵ rf = @f @⇠ · J 1 x y z ⇠ ⌘ ⇣ Equations of Motion Viscoelastic Solid (Kelvin-Voigt Model) Free surface boundary condition ¨ u = 1 ⇢ r · g = r(u + ˙ u) = trace(g) + µ(g + g T ) ⇢ density , µ elastic moduli viscosity u displacement stress tensor ⌧ = · ˆ n = 0 ! Kernel with 12 Streams do l = 1, 400 do k = 1, 400

Note: This page contains sample records for the topic "optimize welding conditions" 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

Low Rank Coal Optimization  

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

Low Rank Coal Optimization Low Rank Coal Optimization NETL Office of Research and Development Project Number: FWP-2012.03.03 Task 4 Project Description NETL's in-house research team is using an integrated approach to combine theory, computational modeling, experiment, and industrial input to develop physics-based methods, models, and tools to support the development and deployment of advanced gasification based devices and systems. The activities in this effort include developing and applying computational and modeling tools to simulate complex flows in applications such as transport or entrained flow gasifiers. TRIG Model Development - The primary objective of this work is to develop a hierarchy of models for numerical simulations of TRIG co-feed conditions that span fast running reduced order models (ROM's) to high fidelity multiphase computational fluid dynamics (CFD) models. Each model will have uncertainty quantification associated with its predictions to allow a user to choose a model based on the trade-offs between computational speed and uncertainty in the predictions.

382

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

383

Optimization Gordon K. Smyth  

E-Print Network [OSTI]

Optimization Gordon K. Smyth Volume 3, pp 1481­1487 in Encyclopedia of Environmetrics (ISBN 0471 #12;Optimization Optimization is the process by which one finds that value of a vector x, say, that maximizes or minimizes a given function f x . The idea of optimization goes to the heart of statistical

Smyth, Gordon K.

384

Assessment of Crack Detection in Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-Frequency Ultrasonic Methods  

SciTech Connect (OSTI)

Studies conducted at the Pacific Northwest National Laboratory in Richland, Washington, have focused on assessing the effectiveness and reliability of novel approaches to nondestructive examination (NDE) for inspecting coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the U.S. Nuclear Regulatory Commission on the effectiveness and reliability of advanced NDE methods as related to the inservice inspection of safety-related components in pressurized water reactors (PWRs). This report provides progress, recent developments, and results from an assessment of low frequency ultrasonic testing (UT) for detection of inside surface-breaking cracks in cast stainless steel reactor piping weldments as applied from the outside surface of the components. Vintage centrifugally cast stainless steel piping segments were examined to assess the capability of low-frequency UT to adequately penetrate challenging microstructures and determine acoustic propagation limitations or conditions that may interfere with reliable flaw detection. In addition, welded specimens containing mechanical and thermal fatigue cracks were examined. The specimens were fabricated using vintage centrifugally cast and statically cast stainless steel materials, which are typical of configurations installed in PWR primary coolant circuits. Ultrasonic studies on the vintage centrifugally cast stainless steel piping segments were conducted with a 400-kHz synthetic aperture focusing technique and phased array technology applied at 500 kHz, 750 kHz, and 1.0 MHz. Flaw detection and characterization on the welded specimens was performed with the phased array method operating at the frequencies stated above. This report documents the methodologies used and provides results from laboratory studies to assess baseline material noise, crack detection, and length-sizing capability for low-frequency UT in cast stainless steel piping.

Anderson, Michael T.; Crawford, Susan L.; Cumblidge, Stephen E.; Denslow, Kayte M.; Diaz, Aaron A.; Doctor, Steven R.

2007-03-01T23:59:59.000Z

385

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

386

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

387

Optimization Online - Gradient Sliding for Composite Optimization  

E-Print Network [OSTI]

Abstract: We consider in this paper a class of composite optimization problems whose objective function is given by the summation of a general smooth and ...

Guanghui Lan

388

Optimization Online - Multilevel Optimization Modeling for Risk ...  

E-Print Network [OSTI]

Abstract: Coherent risk measures have become a popular tool for incorporating risk aversion into stochastic optimization models. For dynamic models in which ...

Jonathan Eckstein

389

Optimization Online - Python Optimization Modeling Objects (Pyomo)  

E-Print Network [OSTI]

Dec 30, 2009 ... Abstract: We describe Pyomo, an open source tool for modeling optimization applications in Python. Pyomo can be used to de fine symbolic ...

William Hart

2009-12-30T23:59:59.000Z

390

Optimization Online - Solving Basis Pursuit: Heuristic Optimality ...  

E-Print Network [OSTI]

Jul 15, 2011 ... We propose a heuristic optimality check as a general tool for l^1-minimization, which often allows for early termination by “guessing” a ...

Dirk A. Lorenz

2011-07-15T23:59:59.000Z

391

Optimization Online - Robust Growth-Optimal Portfolios  

E-Print Network [OSTI]

May 24, 2014 ... Abstract: The growth-optimal portfolio is designed to have maximum ... the asset return distribution, which is not directly observable but must be ...

Napat Rujeerapaiboon

2014-05-24T23:59:59.000Z

392

GLOBAL OPTIMIZATION BY CONTINUOUS GRASP Optimization ...  

E-Print Network [OSTI]

Mar 8, 2006 ... Journal of Computational Physics, 99(1):28–. 32, 1992. ... Handbook of Test Problems in Local and ... Handbook of Applied Optimization.

2006-03-08T23:59:59.000Z

393

Optimization Online - Distributionally Robust Convex Optimization  

E-Print Network [OSTI]

Feb 4, 2013 ... Abstract: Distributionally robust optimization is a paradigm for decision-making under uncertainty where the uncertain problem data is governed ...

Wolfram Wiesemann

2013-02-04T23:59:59.000Z

394

Optimization Online - Convex and Nonsmooth Optimization ...  

E-Print Network [OSTI]

D. Drusvyatskiy, A.D. Ioffe, A.S. Lewis. February 2014. Nonsmooth Optimization Variational Analysis of Circular Cone Programs Jinchuan Zhou, Jein-Shan Chen

395

Optimization Online - Topology optimization of a mechanical ...  

E-Print Network [OSTI]

Aug 26, 2005 ... Topology optimization of a mechanical component subject to dynamical constraints. Sonia Calvel (sonia.calvel ***at*** voila.fr)

Sonia Calvel

2005-08-26T23:59:59.000Z

396

Optimal design of reverse osmosis module networks  

SciTech Connect (OSTI)

The structure of individual reverse osmosis modules, the configuration of the module network, and the operating conditions were optimized for seawater and brackish water desalination. The system model included simple mathematical equations to predict the performance of the reverse osmosis modules. The optimization problem was formulated as a constrained multivariable nonlinear optimization. The objective function was the annual profit for the system, consisting of the profit obtained from the permeate, capital cost for the process units, and operating costs associated with energy consumption and maintenance. Optimization of several dual-stage reverse osmosis systems were investigated and compared. It was found that optimal network designs are the ones that produce the most permeate. It may be possible to achieve economic improvements by refining current membrane module designs and their operating pressures.

Maskan, F.; Wiley, D.E.; Johnston, L.P.M.; Clements, D.J.

2000-05-01T23:59:59.000Z

397

Optimizing PT Arun LNG main heat exchanger  

SciTech Connect (OSTI)

The capacity of a LNG liquefaction unit has been increased by upgrading the refrigeration system, without making changes to the main heat exchanger (MHE). It is interesting, that after all modifications were completed, a higher refrigerant circulation alone could not increase LNG production. However, by optimizing the refrigerant component ratio, the UA of the MHE increased and LNG production improved. This technical evaluation will provide recommendations and show how the evaluation of the internal temperature profile helped optimize the MHE operating conditions.

Irawan, B. [PT Arun NGL Co., Sumatra (Indonesia)

1995-12-01T23:59:59.000Z

398

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

399

Corrosion of aluminum cladding under optimized water conditions  

SciTech Connect (OSTI)

Experience at SRS, ORNL, BNL, and Georgia Institute of Technology involving irradiated aluminum clad fuel and target elements, as well as studies of non-irradiated aluminum indicate that some types of aluminum assemblies can be kept in a continually well-deionized water atmosphere for up to 25 years without problems. SRS experience ranges from 2.75 years for the L-1.1 charge kept in deionized D{sub 2}O{sup 1} to greater than 10 years for assemblies stored in the Receiving Basin for Off-site Fuel (RBOF){sup 2}. Experience at Georgia Institute of Technology reactor in Atlanta yielded the longest value of 25 years without problems. The common denominators in all of the reports is that the water is continually deionized to approximately 2 M{Omega} (2 {times} 10{sup 6}ohms) resistivity and the containers for the water are stainless steel or other non-porous material. This resistivity value is equivalent to a value of 0.5 micromhos or microSiemens conductivity and is reagent grade II quality water.{sup 3} 4 tabs, 26 refs.

Gibbs, A.

1992-07-08T23:59:59.000Z

400

Corrosion of aluminum cladding under optimized water conditions  

SciTech Connect (OSTI)

Experience at SRS, ORNL, BNL, and Georgia Institute of Technology involving irradiated aluminum clad fuel and target elements, as well as studies of non-irradiated aluminum indicate that some types of aluminum assemblies can be kept in a continually well-deionized water atmosphere for up to 25 years without problems. SRS experience ranges from 2.75 years for the L-1.1 charge kept in deionized D[sub 2]O[sup 1] to greater than 10 years for assemblies stored in the Receiving Basin for Off-site Fuel (RBOF)[sup 2]. Experience at Georgia Institute of Technology reactor in Atlanta yielded the longest value of 25 years without problems. The common denominators in all of the reports is that the water is continually deionized to approximately 2 M[Omega] (2 [times] 10[sup 6]ohms) resistivity and the containers for the water are stainless steel or other non-porous material. This resistivity value is equivalent to a value of 0.5 micromhos or microSiemens conductivity and is reagent grade II quality water.[sup 3] 4 tabs, 26 refs.

Gibbs, A.

1992-07-08T23:59:59.000Z

Note: This page contains sample records for the topic "optimize welding conditions" 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

Conditions for the optimality of exponential smoothing forecast procedures  

Science Journals Connector (OSTI)

Exponential smoothing procedures, in particular those recommended byBrown [1962] are used extensively in many areas of economics, business and engineering. It is shown in this paper that: ...

Dr. J. Ledolter; Prof. G. E. P. Box

1978-01-01T23:59:59.000Z

402

Development of Optimization Tool for Air Conditioning System Operation  

E-Print Network [OSTI]

Operations, Berlin, Germany, October 20-22, 2008 Outside air temperature and the absolute air humidity are predicted by the Auto-regressive Integrated Moving Average (ARIMA) model [1],[2]. The solar radiation on a horizontal surface... of the error margin Energy Consumption (set value A) Energy Consumption (set value B) ESL-IC-08-10-55 Proceedings of the Eighth International Conference for Enhanced Building Operations, Berlin, Germany, October 20-22, 2008 J VAV unit is also operated under...

Sumiyoshi, D.; Akashi, Y.

403

Simulation and Optimization of Wind Farm Operations under Stochastic Conditions  

E-Print Network [OSTI]

generation model, wind speed model, and maintenance model. We provide practical insights gained by examining di erent maintenance strategies. To the best of our knowledge, our simulation model is the rst discrete-event simulation model for wind farm...

Byon, Eunshin

2011-08-08T23:59:59.000Z

404

Optimization with multivariate conditional value-at-risk constraints  

E-Print Network [OSTI]

We conduct a computational study for a budget allo- cation problem to ...... Technical report, RUTCOR-Rutgers Center for Operations Research, RRR 33-

2012-12-23T23:59:59.000Z

405

On Second-Order Optimality Conditions for Nonlinear Programming  

E-Print Network [OSTI]

Dec 11, 2006 ... [29] N. I. M. Gould, D. Orban and Ph. L. Toint, GALAHAD: a library of ... [37] X. Liu and J. Sun, A robust primal-dual interior point algorithm for ...

2006-12-14T23:59:59.000Z

406

Cold Climates Heat Pump Design Optimization  

SciTech Connect (OSTI)

Heat pumps provide an efficient heating method; however they suffer from sever capacity and performance degradation at low ambient conditions. This has deterred market penetration in cold climates. There is a continuing effort to find an efficient air source cold climate heat pump that maintains acceptable capacity and performance at low ambient conditions. Systematic optimization techniques provide a reliable approach for the design of such systems. This paper presents a step-by-step approach for the design optimization of cold climate heat pumps. We first start by describing the optimization problem: objective function, constraints, and design space. Then we illustrate how to perform this design optimization using an open source publically available optimization toolbox. The response of the heat pump design was evaluated using a validated component based vapor compression model. This model was treated as a black box model within the optimization framework. Optimum designs for different system configurations are presented. These optimum results were further analyzed to understand the performance tradeoff and selection criteria. The paper ends with a discussion on the use of systematic optimization for the cold climate heat pump design.

Abdelaziz, Omar [ORNL] [ORNL; Shen, Bo [ORNL] [ORNL

2012-01-01T23:59:59.000Z

407

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

408

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

409

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

410

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

411

Global Optimization of Chemical Reactors and Kinetic Optimization  

E-Print Network [OSTI]

Model; 3-D; Monolith; Reactor; Optimization Introduction TheAngeles Global Optimization of Chemical Reactors and KineticGlobal Optimization of Chemical Reactors and Kinetic

ALHUSSEINI, ZAYNA ISHAQ

2013-01-01T23:59:59.000Z

412

E85 Optimized Engine through Boosting, Spray Optimized DIG, VCR...  

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

More Documents & Publications E85 Optimized Engine through Boosting, Spray Optimized GDi, VCR and Variable Valvetrain E85 Optimized Engine Enhanced Ethanol Engine And Vehicle...

413

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

414

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

415

Development of modularized airtight controller for mobile welding robot working in harsh environments  

Science Journals Connector (OSTI)

Abstract This paper proposes the design and validation of a new hermetic controller for mobile robots working in a hazardous environment. Two years ago, we obtained very successful results with regard to the development of the new mobile robot RRX, which can weld, blast, and paint double-hulled structures during the shipbuilding process. At that time, some attempts were made to design a modular and hermetic controller to secure a robust cooling performance and dustproof quality because the temperature is 40–50 °C during the summer, and such operations produce considerable amounts of metallic dust such as fumes. This naturally represents a very hazardous environment for the robot's controller, for which the temperature should be maintained at its rated level, and the body should be kept fully airtight to prevent the inflow of metallic dust. Thus, in that research, heat pipes were successfully adopted to satisfy these design constraints by dissipating the heat from the servomotor drivers and several power units without any airflow into the controller for cooling. The proposed cooling system is composed of heat pipes, cooling fins, fans, and L-shaped brackets for transferring the produced heat from the heating resources to the heat pipes. Experiments were performed in the field to obtain information on the motor driver's heating value and work site temperatures as boundary conditions of the heat transfer problem, and a modular and hermetic controller for mobile robots working in hazardous environments was successfully developed and validated. The obtained experimental results fully support the idea that this design is appropriate for the controller to maintain a stable performance in a harsh environment.

Donghun Lee

2013-01-01T23:59:59.000Z

416

Nonconvex robust optimization  

E-Print Network [OSTI]

We propose a novel robust optimization technique, which is applicable to nonconvex and simulation-based problems. Robust optimization finds decisions with the best worst-case performance under uncertainty. If constraints ...

Teo, Kwong Meng

2007-01-01T23:59:59.000Z

417

Optimization of hybrid dynamic/steady-state processes using process integration  

E-Print Network [OSTI]

-batch water purification system was optimized. This problem showed how process integration could be used to optimize a hybrid system and gain insights into the process under many different operating conditions....

Grooms, Daniel Douglas

2009-06-02T23:59:59.000Z

418

Friction Stir Welding of ODS Steels Â… 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

419

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

420

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

Note: This page contains sample records for the topic "optimize welding conditions" 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

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

422

Extreme Optimization Announcements  

E-Print Network [OSTI]

Extreme Optimization Announcements Assignment 3 due tomorrow @ 5pm. No late days on Extreme, we will hold extra office hours during regular section times. #12;Extreme Optimization Extreme University Fall 2014 #12;Extreme Optimization The radiotherapy problem Saving Lives: Radiotherapy Radiation

Chen, Yiling

423

Optimizing robot placement for visit-point tasks  

SciTech Connect (OSTI)

We present a manipulator placement algorithm for minimizing the length of the manipulator motion performing a visit-point task such as spot welding. Given a set of points for the tool of a manipulator to visit, our algorithm finds the shortest robot motion required to visit the points from each possible base configuration. The base configurations resulting in the shortest motion is selected as the optimal robot placement. The shortest robot motion required for visiting multiple points from a given base configuration is computed using a variant of the traveling salesman algorithm in the robot joint space and a point-to-point path planner that plans collision free robot paths between two configurations. Our robot placement algorithm is expected to reduce the robot cycle time during visit- point tasks, as well as speeding up the robot set-up process when building a manufacturing line.

Hwang, Y.K.; Watterberg, P.A.

1996-06-01T23:59:59.000Z

424

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

425

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

426

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

427

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

428

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

429

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

430

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

431

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

432

Optimization Online - Global Optimization Submissions - 2012  

E-Print Network [OSTI]

Proximal Point Method for Minimizing Quasiconvex Locally Lipschitz Functions ... Formulas for calculating the extremum ranks and inertias of a four-term quadratic ... Branch-and-Lift Algorithm for Deterministic Global Optimization in Nonlinear ...

433

Optimization Online - Nonlinear Optimization Submissions - 2012  

E-Print Network [OSTI]

Reformulation of a model for hierarchical divisive graph modularity ... Approximation of Matrix Rank Function and Its Application to Matrix Rank ... MSS: MATLAB software for L-BFGS trust-region subproblems for large-scale optimization

434

Distributionally Robust Convex Optimization - Optimization Online  

E-Print Network [OSTI]

1Imperial College Business School, Imperial College London, United Kingdom. 2College .... to biased optimization results with poor out-of-sample performance. ...... Question. Is there a vector y ? {0,1}. P such that Ey ? f and g y ? ?? ...... (

2013-09-22T23:59:59.000Z

435

Optimal Airflow Control for Laboratory Air Handling Unit (LAHU) Systems  

E-Print Network [OSTI]

than the cooling energy does. Or, the heating energy reduces as the cooling energy decreases for the LAHU. If the humidification and the heating energy have the same price, the optimal thermal energy consumption also means the optimal thermal..., the restriction conditions are reduced to: oa c t T ? ?= 1, 1? (23) oa c t T ? ?= 2, 2? (24) 1 = (25) 0121 =? ? ? or ?? ? ?? 1121 (26) 2 = or 12 = (27) The optimal airflow control is a two-variable restricted...

Cui, Y.; Liu, M.; Conger, K.

2002-01-01T23:59:59.000Z

436

Modeling and optimization of HVAC energy consumption  

Science Journals Connector (OSTI)

A data-driven approach for minimization of the energy to air condition a typical office-type facility is presented. Eight data-mining algorithms are applied to model the nonlinear relationship among energy consumption, control settings (supply air temperature and supply air static pressure), and a set of uncontrollable parameters. The multiple-linear perceptron (MLP) ensemble outperforms other models tested in this research, and therefore it is selected to model a chiller, a pump, a fan, and a reheat device. These four models are integrated into an energy optimization model with two decision variables, the setpoint of the supply air temperature and the static pressure in the air handling unit. The model is solved with a particle swarm optimization algorithm. The optimization results have demonstrated the total energy consumed by the heating, ventilation, and air-conditioning system is reduced by over 7%.

Andrew Kusiak; Mingyang Li; Fan Tang

2010-01-01T23:59:59.000Z

437

Airfoil Optimization Using Practical Aerodynamic Design Requirements  

E-Print Network [OSTI]

Airfoil Optimization Using Practical Aerodynamic Design Requirements Howard P. Buckley, Beckett Y., Toronto, Ontario, M3H 5T6, Canada Practical aerodynamic design problems must balance the goal the aerodynamic constraints imposed at the off-design operating conditions to be treated explicitly. Both methods

Zingg, David W.

438

Optimization of Steam Network in Tehran Oil Refinery  

E-Print Network [OSTI]

case study and its steam network is analyzed. At the first step, using STAR software, the steam network is simulated and then optimized, which determines the optimum conditions. In this regard, energy saving potential was identified and total operating...

Khodaie, H.; Nasr, M. R. J.

2008-01-01T23:59:59.000Z

439

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

440

Layering as Optimization Decomposition 3-1 Layering as OptimizationLayering as Optimization  

E-Print Network [OSTI]

1 Layering as Optimization Decomposition 3-1 Layering as OptimizationLayering as Optimization DecompositionDecomposition Layering as Optimization Decomposition 3-2 CONTENTSCONTENTS Introduction (Marta;2 Layering as Optimization Decomposition 3-3 Layering as Optimization Decomposition Introduction By Marta

Fan, Xingzhe

Note: This page contains sample records for the topic "optimize welding conditions" 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

Computer Graphics to Show Optimal Smoothing and Trend Adjustments for Exponential Forecasts  

Science Journals Connector (OSTI)

When simulating various demand conditions and then determining the best factors for both smoothing and trend adjustments in an exponential smoothing model, both the optimal values and the...

David B. Hoffman; Ramachandran Bharath; Carol M. Carlson

1983-01-01T23:59:59.000Z

442

Optimization of pulsed-DEER measurements for Gd-based labels...  

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

for Gd-based labels: choice of operational frequencies, pulse durations and positions, Abstract: In this work, the experimental conditions and parameters necessary to optimize...

443

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

444

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

445

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.

Lévesque, 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

446

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

447

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.

448

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.

449

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

450

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

451

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

452

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

453

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

454

Energy optimization system  

DOE Patents [OSTI]

A system for optimizing customer utility usage in a utility network of customer sites, each having one or more utility devices, where customer site is communicated between each of the customer sites and an optimization server having software for optimizing customer utility usage over one or more networks, including private and public networks. A customer site model for each of the customer sites is generated based upon the customer site information, and the customer utility usage is optimized based upon the customer site information and the customer site model. The optimization server can be hosted by an external source or within the customer site. In addition, the optimization processing can be partitioned between the customer site and an external source.

Zhou, Zhi; de Bedout, Juan Manuel; Kern, John Michael; Biyik, Emrah; Chandra, Ramu Sharat

2013-01-22T23:59:59.000Z

455

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

456

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

457

Improvements in 500-kHz Ultrasonic Phased-Array Probe Designs for Evaluation of Thick Section Cast Austenitic Stainless Steel Piping Welds  

SciTech Connect (OSTI)

PNNL has been studying and performing confirmatory research on the inspection of piping welds in coarse-grained steels for over 30 years. More recent efforts have been the application of low frequency phased array technology to this difficult to inspect material. The evolution of 500 kHz PA probes and the associated electronics and scanning protocol are documented in this report. The basis for the probe comparisons are responses from one mechanical fatigue crack and two thermal fatigue cracks in large-bore cast mockup specimens on loan from the Electric Power Research Institution. One of the most significant improvements was seen in the use of piezo-composite elements in the later two probes instead of the piezo-ceramic material used in the prototype array. This allowed a reduction in system gain of 30 dB and greatly reduced electronic noise. The latest probe had as much as a 5 dB increase in signal to noise, adding to its flaw discrimination capability. The system electronics for the latest probe were fully optimized for a 500 kHz center frequency, however significant improvements were not observed in the center frequency of the flaw responses. With improved scanner capabilities, smaller step sizes were used, allowing both line and raster data improvements to be made with the latest probe. The small step sizes produce high resolution images that improve flaw discrimination and, along with the increased signal-to-noise ratio inherent in the latest probe design, enhanced detection of the upper regions of the flaw make depth sizing more plausible. Finally, the physical sizes of the probes were progressively decreased allowing better access to the area of interest on specimens with weld crowns, and the latest probe was designed with non-integral wedges providing flexibility in focusing on different specimen geometries.

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

2011-02-01T23:59:59.000Z

458

2009 - Optimization Online  

E-Print Network [OSTI]

Modeling the Mobile Oil Recovery Problem as a Multiobjective Vehicle Routing Problem ... Optimal Security Response to Attacks on Open Science Grids

459

E85 Optimized Engine  

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

of work * Approach * Barriers * Performance Measures and Accomplishments * Technology Transfer * Plans for Next Fiscal Year * Summary 2 E85 Optimized Purpose of Work Engine *...

460

3531.ps - Optimization Online  

E-Print Network [OSTI]

Jul 13, 2012 ... Stochastic optimization of a multireservoir hydroelectric system : A decomposition approach. Water Ressource Research, 21(6):779–792, June ...

2012-07-13T23:59:59.000Z

Note: This page contains sample records for the topic "optimize welding conditions" from the National Library of EnergyBeta (NLEBeta).
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461

Postscript - Optimization Online  

E-Print Network [OSTI]

Technical Report R-6469, AERE Harwell Labo-. ratory, Harwell, Oxfordshire, England, 1970. [21] M. J. D. Powell. A new algorithm for unconstrained optimization ...

462

Euler's fluid equations: Optimal Control vs Optimization  

E-Print Network [OSTI]

An optimization method used in image-processing (metamorphosis) is found to imply Euler's equations for incompressible flow of an inviscid fluid, without requiring that the Lagrangian particle labels exactly follow the flow lines of the Eulerian velocity vector field. Thus, an optimal control problem and an optimization problem for incompressible ideal fluid flow both yield the \\emph {same} Euler fluid equations, although their Lagrangian parcel dynamics are \\emph{different}. This is a result of the \\emph{gauge freedom} in the definition of the fluid pressure for an incompressible flow, in combination with the symmetry of fluid dynamics under relabeling of their Lagrangian coordinates. Similar ideas are also illustrated for SO(N) rigid body motion.

Darryl D. Holm

2009-09-28T23:59:59.000Z

463

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

464

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 Institute’s (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

465

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 4 mm 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

466

Toward optimized code generation through model-based optimization  

E-Print Network [OSTI]

Toward optimized code generation through model- based optimization Asma Charfi, Chokri Mraidha with in RTES development is linked to the optimization of their software part. Although automatic code generation and the use of optimizing compilers bring some answers to application optimization issue, we

Paris-Sud XI, Université de

467

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

468

Blackbox and non-blackbox optimization: A common perspective  

SciTech Connect (OSTI)

The SEARCH (Search Envisioned As Relation & Class Hierarchizing) framework developed elsewhere offered an alternate perspective toward blackbox optimization (BBO)-optimization in absence of domain knowledge. This paper argues that the fundamental concepts are also applicable to non-blackbox optimization (NBBO)-optimization in presence of information about the search domain and objective function. The SEARCH framework investigates the conditions essential for transcending the limits of random enumerative search using a framework developed in terms of relations, classes and partial ordering. This paper reviews some of the main results of that work and describes its generality by ordering different popular BBO and NBBO algorithms.

Karguptra, H.

1996-09-01T23:59:59.000Z

469

Reverse Osmosis Optimization  

Broader source: Energy.gov [DOE]

Report assesses techniques for optimizing reverse osmosis (RO) systems to increase RO system performance and water efficiency. It provides a general description of RO systems, the influence of RO systems on water use, and key areas where RO systems can be optimized to reduce water and energy consumption.

470

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].

471

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

472

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

473

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

474

HVAC Optimized Heat Exchangers Research Project | Department of Energy  

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

Optimized Heat Exchangers Research Optimized Heat Exchangers Research Project HVAC