Sample records for tungsten arc welding

  1. Heat transfer in gas tungsten arc welding

    SciTech Connect (OSTI)

    Smartt, H.B.; Stewart, J.A.; Einerson, C.J.

    1986-05-01T23:59:59.000Z

    The heat transferred from an electrode negative, argon gas tungsten arc to an anode has been measured for a wide range of conditions suitable for mechanized welding applications. The results are given as (1) the arc efficiency; and (2) the anode heat and current input distribution functional shapes and radii for various anode materials and groove shapes over a wide range of current and voltage, using different electrode geometries, as well as both He and Ar-He shielding gases. The nominal arc is Gaussian with a diameter of about 4 mm and a heat transfer efficiency to the anode of about 75%. Variations from these values are discussed in terms of current knowledge of the electrical and thermal energy transport mechanisms. A new method of measuring the heat transferred from the arc to the anode, using a boiling liquid nitrogen calorimeter, has been developed which gives rapid, accurate values.

  2. A Glove Box Enclosed Gas-Tungsten Arc Welding System

    SciTech Connect (OSTI)

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

    1999-07-01T23:59:59.000Z

    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.

  3. Control of Gas Tungsten Arc welding pool shape by trace element addition to the weld pool

    DOE Patents [OSTI]

    Heiple, C.R.; Burgardt, P.

    1984-03-13T23:59:59.000Z

    An improved process for Gas Tungsten Arc welding maximizes the depth/width ratio of the weld pool by adding a sufficient amount of a surface active element to insure inward fluid flow, resulting in deep, narrow welds. The process is especially useful to eliminate variable weld penetration and shape in GTA welding of steels and stainless steels, particularly by using a sulfur-doped weld wire in a cold wire feed technique.

  4. Gas-tungsten arc welding of aluminum alloys

    DOE Patents [OSTI]

    Frye, Lowell D. (Kingston, TN)

    1984-01-01T23:59:59.000Z

    A gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to provide a mirror finish thereon having a surface roughness in the order of about one microinch. The fay surfaces are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy contiguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

  5. Gas-tungsten arc welding of aluminum alloys

    DOE Patents [OSTI]

    Frye, L.D.

    1982-03-25T23:59:59.000Z

    The present invention is directed to a gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to profice a mirror finish thereon having a surface roughness in the order of about one microinch. The fay surface are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy continguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

  6. Gas-tungsten arc welding of aluminum alloys

    SciTech Connect (OSTI)

    Frye, L.D.

    1984-11-20T23:59:59.000Z

    A gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to provide a mirror finish thereon having a surface roughness in the order of about one micro-inch. The fay surfaces are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy contiguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

  7. Parametric Studies Of Weld Quality Of Tungsten Inert Gas Arc Welding Of Stainless Steel

    SciTech Connect (OSTI)

    Kumar Pal, Pradip; Nandi, Goutam; Ghosh, Nabendu [Mechanical Engineering Department, Jadavpur University, Kolkata-700032 (India)

    2011-01-17T23:59:59.000Z

    Effect of current and gas flow rate on quality of weld in tungsten inter gas arc welding of austenitic stainless steel has been studied in the present work through experiments and analyses. Butt welded joints have been made by using several levels of current and gas flow rate. The quality of the weld has been evaluated in terms of ultimate and breaking strengths of the welded specimens. The observed data have been interpreted, discussed and analyzed by using Grey--Taguchi methodology. Optimum parametric setting has been predicted and validated as well.

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

    SciTech Connect (OSTI)

    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

    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.

  9. Theoretical analysis of weld pool behavior in the pulsed current Gas Tungsten Arc Welding (GTAW) process

    SciTech Connect (OSTI)

    Tsai, C.L. (Ohio State Univ., Columbus (United States)); Hou, C.A. (Howard Univ., Washington, DC (United States))

    1988-02-01T23:59:59.000Z

    A general three-dimensional, closed-form welding heat-flow solution, which is capable of analyzing thermal behavior of the weldment in its transient state and/or under time-dependent power change during welding, is presented. The analytical model utilizes the finite heat source theory with a Gaussian distribution and also considers the effects of finite plate thickness. The numerical values of the solution are calculated using the computational schemes on a minicomputer. In this paper the welding parameters of the pulsed current Gas Tungsten Arc Welding (GTAW) were studied using the solution. Two sets of pulsation parameters were analyzed and their sensitivity to the heat input control were evaluated.

  10. A calorimetric-based comparison of gas tungsten and plasma arc welding processes

    SciTech Connect (OSTI)

    Knorovsky, G.A.; Fuerschbach, P.W.

    1988-01-01T23:59:59.000Z

    Measurements of arc and melting efficiencies have been made for pulsed and continuous mode Gas Tungsten Arc Welding (GTAW) and Plasma Arc Welding (PAW) processes. Welds were made on 2.5 mm total thickness pure Ni and 304 Stainless Steel in a standing edge weld geometry at constant nominal machine output settings which varied average current with travel speed. Under continuous current conditions, the measured heat input remained approximately constant for the conditions examined (250-1250 mm/min), while melting efficiency increased dramatically (0-/approximately/0.4). Arc efficiencies were relatively constant, remaining in the range of /approximately/0.75-0.85 for GTAW and somewhat less for PAW. Values of melting efficiency for Ni were slightly less than those for 304 when compared at similar travel speeds, though both tended toward the same limit (/approximately/0.4). The PAW results were not appreciably higher than the GTAW. In addition to melting efficiency the centerline depth of penetration was also measured. In contrast to the GTAW results, which increased with speed at lower travel speeds and then plateaued at 0.8 mm, the PAW results increased monotonically with speed to a maximum of 1.0 mm. In conclusion, calorimetric measurements of nonconsumable arc welding processes have been found helpful in understanding conditions under which efficient arc welds with minimal heat inputs for a desired weld penetration can be made. 10 figs.

  11. GTAW penetration based on electrode tip location versus weld joint center line. [Gas Tungsten Arc Welding (GTAW)

    SciTech Connect (OSTI)

    Daumeyer, G.J. III.

    1992-11-01T23:59:59.000Z

    Gas Tungsten Arc Welding (GTAW) is often the chosen process for final enclosure welds of heat sensitive electrical and electronic product. GTAW is used to produce welds that satisfy design requirements (usually a penetration requirement) and not expose the product to such high heat that would cause unwanted damage. An important variable in the GTAW process is the location of the Electrode tip over the weld joint center line. This study shows the tolerance of positional location over a narrow scope. Using coupons which represent the W88 container weld joint geometry, penetration vs. electrode tip positional location (offset) is investigated. Results indicate a positional location tolerance of [plus minus] 0.008 in. is acceptable. Several different major components (MCS) supporting various weapons programs require low heat input GTA welds. The electrode tip positional location tolerance is determined by each MC's weld joint tolerances and heat sensitivity. For this short study, the weld joint geometry of a container weld was used. These coupons were welded with the specified weld schedule and one additional weld schedule in order to show the relationship based on both travel speed and gap. Multiple coupon welds were made to eliminate error in the results. Within the scope of this research, a positional tolerance of [plus minus] 0.008 in. of the electrode center over the weld joint center is required. For other MCs this tolerance may be tighter or more relaxed depending upon the specific considerations.

  12. Vaccum Gas Tungsten Arc Welding, phase 1. Technical report, October 1993-March 1995

    SciTech Connect (OSTI)

    Weeks, J.L.; Krotz, P.D.; Todd, D.T.; Liaw, Y.K.

    1995-03-01T23:59:59.000Z

    This two year program will investigate Vacuum Gas Tungsten Arc Welding (VGTAW) as a method to modify or improve the weldability of normally difficult-to-weld materials. VGTAW appears to offer a significant improvement in weldability because of the clean environment and lower heat input needed. The overall objective of the program is to develop the VGTAW technology and implement it into a manufacturing environment that will result in lower cost, better quality and higher reliability aerospace components for the space shuttle and other NASA space systems. Phase 1 of this program was aimed at demonstrating the process`s ability to weld normally difficult-to-weld materials. Phase 2 will focus on further evaluation, a hardware demonstration and a plan to implement VGTAW technology into a manufacturing environment. During Phase 1, the following tasks were performed: (1) Task 11000 Facility Modification - an existing vacuum chamber was modified and adapted to a GTAW power supply; (2) Task 12000 Materials Selection - four difficult-to-weld materials typically used in the construction of aerospace hardware were chosen for study; (3) Task 13000 VGTAW Experiments - welding experiments were conducted under vacuum using the hollow tungsten electrode and evaluation. As a result of this effort, two materials, NARloy Z and Incoloy 903, were downselected for further characterization in Phase 2; and (4) Task 13100 Aluminum-Lithium Weld Studies - this task was added to the original work statement to investigate the effects of vacuum welding and weld pool vibration on aluminum-lithium alloys.

  13. Remote reactor repair: GTA (gas tungsten Arc) weld cracking caused by entrapped helium

    SciTech Connect (OSTI)

    Kanne, W.R. Jr.

    1988-01-01T23:59:59.000Z

    A repair patch was welded to the wall of a nuclear reactor tank using remotely controlled thirty-foot long robot arms. Further repair was halted when gas tungsten arc (GTA) welds joining type 304L stainless steel patches to the 304 stainless steel wall developed toe cracks in the heat-affected zone (HAZ). The role of helium in cracking was investigated using material with entrapped helium from tritium decay. As a result of this investigation, and of an extensive array of diagnostic tests performed on reactor tank wall material, helium embrittlement was shown to be the cause of the toe cracks.

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

    E-Print Network [OSTI]

    Eagar, Thomas W.

    emission, were also determined. An improved image of the weld pool can be obtained by operating within will require development of new sensor systems. As the "Yelding arc is a harsh environment, noncontacting to control joint tracking and weld E. W. KIM, C. ALLEMAND and T. W. EAGAR are with the Massachusetts

  15. Heat and mass transfer in the gas tungsten and gas metal arc welding processes

    SciTech Connect (OSTI)

    Watkins, A.D; Smartt, H.B.; Einerson, C.J.; Watkins, J.A.

    1990-01-01T23:59:59.000Z

    The heat transferred from an electrode negative, argon gas tungsten arc to an anode was measured for a wide range of conditions suitable for mechanized welding. The results are given as (1) the arc efficiency and (2) the anode heat and current input distributions for various anode materials over a range of current and voltage. The nominal arc is Gaussian, {approximately}4 mm in diameter, with {approximately}75{percent}heat transfer efficiency. Variations from these values are discussed in terms of the electrical and thermal energy transport mechanisms. Heat transferred to the workpiece (cathode) during direct current, electrode positive gas metal arc welding (GMAW) was measured for various parameters applicable to machine welding. The results are presented as a function of electrode speed for changing voltages and contact tip to workpiece distances. The total heat transfer efficiency was nominally 85{percent} for a 0.89 mm diameter steel electrode using an argon-2{percent} oxygen shielding gas; the nominal heat transfer efficiency of the droplet component was 40{percent}. The average droplet temperatures ranged from 2400 to 3100 K, depending on the process parameters. A new method of measuring the heat transferred from the arc to the workpiece, using a boiling liquid nitrogen calorimeter, has been developed that gives rapid, accurate values. 20 refs., 8 figs., 2 tabs.

  16. On-line weld penetration detection and control in automated gas tungsten arc welding. Ph.D. Thesis

    SciTech Connect (OSTI)

    Banerjee, P.

    1994-01-01T23:59:59.000Z

    The present work was undertaken to study the feasibility of monitoring and controlling weld penetration variations in real-time using an infrared detector. Weld penetration variations induced on mild steel plates were examined with an infrared detector and the acquired data analyzed to detect weld penetration variations using a mathematical analysis. Selected weld penetration indicators were developed and used to demonstrate on-line weld penetration control. A three-dimensional solid-state, transient heat transfer model was also developed to help identify key changes in thermal distributions which could be used as weld penetration indicators. A transient three-dimensional heat transfer model was used to solve the differential energy balance for the GTA welding process. The computed temperatures obtained from the model were used to determine the variation of the isothermal map, surface temperature profile and temperature gradient with weld penetration. Good agreement between experimental and computed indicators was obtained. Gas tungsten arc welds were performed on steel plates with intentionally introduced defects such as sudden thickness changes and minor element content changes. Extensive mathematical analysis helped correlate weld penetration variations to parameters such as the peak infrared intensity, intensity gradient over a fixed distance, intensity gradient at the inflection points in the first differential of the intensity profile (linescan), computed width of the weld pool, intensity gradient at a point in the weld pool, area enclosed by the linescan and area enclosed by the linescan after compensating for background illumination. The shape of the weld pool front was also determined from a differential analysis of the infrared data. Inconsistent behavior of some weld penetration indicators led to their elimination from the selection process for the best error signal.

  17. Progress report on a fully automatic Gas Tungsten Arc Welding (GTAW) system development

    SciTech Connect (OSTI)

    Daumeyer, G.J. III

    1994-12-01T23:59:59.000Z

    A plan to develop a fully automatic gas tungsten arc welding (GTAW) system that will utilize a vision-sensing computer (which will provide in-process feedback control) is presently in work. Evaluations of different technological aspects and system design requirements continue. This report summaries major activities in the plan`s successful progress. The technological feasibility of producing the fully automated GTAW system has been proven. The goal of this process development project is to provide a production-ready system within the shortest reasonable time frame.

  18. Narrow groove gas tungsten arc welding of ASTM A508 Class 4 steel for improved toughness properties

    SciTech Connect (OSTI)

    Penik, M.A. Jr. [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1997-04-01T23:59:59.000Z

    Welding of heavy section steel has traditionally used the automatic submerged arc welding (ASAW) process because of the high deposition rates achievable. However, the properties, particularly fracture toughness, of the weld are often inferior when compared to base material. This project evaluated the use of narrow groove gas tungsten arc welding (GTAW) to improve weld material properties. The welding procedures were developed for ASTM A508 Class 4 base material using a 1% Ni filler material complying to AWS Specification A.23-90-EF3-F3-N. A narrow groove joint preparation was used in conjunction with the GTAW process so competitive fabrication rates could be achieved when compared to the ASAW process. Weld procedures were developed to refine weld substructure to achieve better mechanical properties. Two heaters of weld wire were used to examine the effects of minor filler metal chemistry differences on weld mechanical properties. Extensive metallographic evaluations showed excellent weld quality with a refined microstructure. Chemical analysis of the weld metal showed minimal weld dilution by the base metal. Mechanical testing included bend and tensile tests to ensure weld quality and strength. A Charpy impact energy curve versus temperature and fracture toughness curve versus temperature were developed for each weld wire heat. Results of fracture toughness and Charpy impact testing indicated an improved transition temperature closer to that of the base material properties.

  19. Microstructure evolution of Al/Mg butt joints welded by gas tungsten arc with Zn filler metal

    SciTech Connect (OSTI)

    Liu Fei; Zhang Zhaodong; Liu Liming, E-mail: liulm@dlut.edu.cn

    2012-07-15T23:59:59.000Z

    Based on the idea of alloying welding seam, Gas tungsten arc welding method with pure Zn filler metal was chosen to join Mg alloy and Al alloy. The microstructures, phases, element distribution and fracture morphology of welding seams were examined. The results indicate that there was a transitional zone in the width of 80-100 {mu}m between the Mg alloy substrate and fusion zone. The fusion zone was mainly composed of MgZn{sub 2}, Zn-based solid solution and Al-based solid solution. The welding seam presented distinct morphology in different location owning to the quite high cooling rate of the molten pool. The addition of Zn metal could prevent the formation of Mg-Al intermetallics and form the alloyed welding seam during welding. Therefore, the tensile strengths of joints have been significantly improved compared with those of gas tungsten arc welded joints without Zn metal added. Highlights: Black-Right-Pointing-Pointer Mg alloy AZ31B and Al alloy 6061 are welded successfully. Black-Right-Pointing-Pointer Zinc wire is employed as a filler metal to form the alloyed welding seam. Black-Right-Pointing-Pointer An alloyed welding seam is benefit for improving of the joint tensile strength.

  20. Abnormal macropore formation during double-sided gas tungsten arc welding of magnesium AZ91D alloy

    SciTech Connect (OSTI)

    Shen Jun [College of Mechanical Engineering, Chongqing University, Chongqing 400044 (China)], E-mail: shenjun2626@163.com; You Guoqiang; Long Siyuan [College of Mechanical Engineering, Chongqing University, Chongqing 400044 (China); Pan Fusheng [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2008-08-15T23:59:59.000Z

    One of the major concerns during gas tungsten arc (GTA) welding of cast magnesium alloys is the presence of large macroporosity in weldments, normally thought to occur from the presence of gas in the castings. In this study, a double-sided GTA welding process was adopted to join wrought magnesium AZ91D alloy plates. Micropores were formed in the weld zone of the first side that was welded, due to precipitation of H{sub 2} as the mushy zone freezes. When the reverse side was welded, the heat generated caused the mushy zone in the initial weld to reform. The micropores in the initial weld then coalesced and expanded to form macropores by means of gas expansion through small holes that are present at the grain boundaries in the partially melted zone. Macropores in the partially melted zone increase with increased heat input, so that when a filler metal is used the macropores are smaller in number and in size.

  1. Computational modeling of GTA (gas tungsten arc) welding with emphasis on surface tension effects

    SciTech Connect (OSTI)

    Zacharia, T.; David, S.A.

    1990-01-01T23:59:59.000Z

    A computational study of the convective heat transfer in the weld pool during gas tungsten arch (GTA) welding of Type 304 stainless steel is presented. The solution of the transport equations is based on a control volume approach which utilized directly, the integral form of the governing equations. The computational model considers buoyancy and electromagnetic and surface tension forces in the solution of convective heat transfer in the weld pool. In addition, the model treats the weld pool surface as a deformable free surface. The computational model includes weld metal vaporization and temperature dependent thermophysical properties. The results indicate that consideration of weld pool vaporization effects and temperature dependent thermophysical properties significantly influence the weld model predictions. Theoretical predictions of the weld pool surface temperature distributions and the cross-sectional weld pool size and shape wee compared with corresponding experimental measurements. Comparison of the theoretically predicted and the experimentally obtained surface temperature profiles indicated agreement with {plus minus} 8%. The predicted weld cross-section profiles were found to agree very well with actual weld cross-sections for the best theoretical models. 26 refs., 8 figs.

  2. Mechanical properties and microstructures of a magnesium alloy gas tungsten arc welded with a cadmium chloride flux

    SciTech Connect (OSTI)

    Zhang, Z.D. [State Key Laboratory of Material Surface Modification by Laser, Ion, and Beams, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Liu, L.M. [State Key Laboratory of Material Surface Modification by Laser, Ion, and Beams, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)], E-mail: liulm@dlut.edu.cn; Shen, Y.; Wang, L. [State Key Laboratory of Material Surface Modification by Laser, Ion, and Beams, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

    2008-01-15T23:59:59.000Z

    Gas tungsten arc (GTA) welds were prepared on 5-mm thick plates of wrought magnesium AZ31B alloy, using an activated flux. The microstructural characteristics of the weld joint were investigated using optical and scanning microscopy, and the fusion zone microstructure was compared with that of the base metal. The elemental distribution was also investigated by electron probe microanalysis (EPMA). Mechanical properties were determined by standard tensile tests on small-scale specimens. The as-welded fusion zone prepared using a CdCl{sub 2} flux exhibited a larger grain size than that prepared without flux; the microstructure consisted of matrix {alpha}-Mg, eutectic {alpha}-Mg and {beta}-Al{sub 12}Mg{sub 17}. The HAZ was observed to be slightly wider for the weld prepared with a CdCl{sub 2} flux compared to that prepared without flux; thus the tensile strength was lower for the flux-prepared weld. The fact that neither Cd nor Cl was detected in the weld seam by EPMA indicates that the CdCl{sub 2} flux has a small effect on convection in the weld pool.

  3. Abnormal distribution of microhardness in tungsten inert gas arc butt-welded AZ61 magnesium alloy plates

    SciTech Connect (OSTI)

    Xu Nan [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Shen Jun, E-mail: shenjun2626@163.com [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Xie Weidong; Wang Linzhi; Wang Dan; Min Dong [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2010-07-15T23:59:59.000Z

    In this study, the effects of heat input on the distribution of microhardness of tungsten inert gas (TIG) arc welded hot-extruded AZ61 magnesium alloy joints were investigated. The results show that with an increase of heat input, the distributions of microhardness at the top and bottom of the welded joints are different because they are determined by both the effect of grain coarsening and the effect of dispersion strengthening. With an increase of the heat input, the microhardness of the heat-affected zone (HAZ) at the top and bottom of welded joints and the fusion zone (FZ) at the bottom of welded joints decreased gradually, while the microhardness of the FZ at the top of welded joints decreased initially and then increased sharply. The reason for the abnormal distribution of microhardness of the FZ at the top of the welded joints is that this area is close to the heat source during welding and then large numbers of hard {beta}-Mg{sub 17}(Al,Zn){sub 12} particles are precipitated. Hence, in this case, the effect of dispersion strengthening dominated the microhardness.

  4. Gas tungsten arc welder with electrode grinder

    DOE Patents [OSTI]

    Christiansen, David W. (Kennewick, WA); Brown, William F. (West Richland, WA)

    1984-01-01T23:59:59.000Z

    A welder for automated closure of fuel pins by a gas tungsten arc process in which a rotating length of cladding is positioned adjacent a welding electrode in a sealed enclosure. An independently movable axial grinder is provided in the enclosure for refurbishing the used electrode between welds.

  5. Environmental embrittlement of iron-aluminide alloy FA-129 during gas tungsten arc welding

    SciTech Connect (OSTI)

    Fasching, A.A.; Edwards, G.R. [Colorado School of Mines, Golden, CO (United States); David, S.A. [Oak Ridge National Lab, Oak Ridge, TN (United States)

    1994-12-31T23:59:59.000Z

    Iron aluminides are susceptible to hydrogen cold cracking during gastungsten arc welding (GTAW). Cracking occurs by brittle fracture in the fusion zone, which has been attributed to excessive grain growth during solidification. To further investigate hydrogen cold cracking in iron aluminides and, specifically, to study the effect of base material grain size on fusion zone cracking susceptibility, base materials of varying grain size were GTAW. The specimens for this investigation came from a production-sized vacuum arc remelt (VAR) ingot. The results of this investigation showed that changes in either the base material thermomechanical processing or the common welding parameters could not easily be used to refine the fusion zone grain size. This investigation showed that conventional GTAW produced coarse fusion zone grain structures even in fine-grained base material. The results also revealed that fracture strength decreased only slightly with a decrease in heat input, but exhibited a dramatic decrease as the water vapor content increased. in addition, the unrecrystallized base material showed the greatest susceptibility toward hydrogen cold cracking. Fracture stress versus grain size plots at different levels of water vapor were produced for iron-aluminide alloy FA-129.

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

    SciTech Connect (OSTI)

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

    1982-10-01T23:59:59.000Z

    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.

  7. Laser Assisted Plasma Arc Welding

    SciTech Connect (OSTI)

    FUERSCHBACH,PHILLIP W.

    1999-10-05T23:59:59.000Z

    Experiments have been performed using a coaxial end-effecter to combine a focused laser beam and a plasma arc. The device employs a hollow tungsten electrode, a focusing lens, and conventional plasma arc torch nozzles to co-locate the focused beam and arc on the workpiece. Plasma arc nozzles were selected to protect the electrode from laser generated metal vapor. The project goal is to develop an improved fusion welding process that exhibits both absorption robustness and deep penetration for small scale (< 1.5 mm thickness) applications. On aluminum alloys 6061 and 6111, the hybrid process has been shown to eliminate hot cracking in the fusion zone. Fusion zone dimensions for both stainless steel and aluminum were found to be wider than characteristic laser welds, and deeper than characteristic plasma arc welds.

  8. Welding arc initiator

    DOE Patents [OSTI]

    Correy, T.B.

    1989-05-09T23:59:59.000Z

    An improved inert gas shielded tungsten arc welder is disclosed of the type wherein a tungsten electrode is shielded within a flowing inert gas, and, an arc, following ignition, burns between the energized tungsten electrode and a workpiece. The improvement comprises in combination with the tungsten electrode, a starting laser focused upon the tungsten electrode which to ignite the electrode heats a spot on the energized electrode sufficient for formation of a thermionic arc. Interference problems associated with high frequency starters are thus overcome. 3 figs.

  9. Welding arc initiator

    DOE Patents [OSTI]

    Correy, Thomas B. (Richland, WA)

    1989-01-01T23:59:59.000Z

    An improved inert gas shielded tungsten arc welder is disclosed of the type wherein a tungsten electrode is shielded within a flowing inert gas, and, an arc, following ignition, burns between the energized tungsten electrode and a workpiece. The improvement comprises in combination with the tungsten electrode, a starting laser focused upon the tungsten electrode which to ignite the electrode heats a spot on the energized electrode sufficient for formation of a thermionic arc. Interference problems associated with high frequency starters are thus overcome.

  10. DC arc weld starter

    DOE Patents [OSTI]

    Campiotti, Richard H. (Tracy, CA); Hopwood, James E. (Oakley, CA)

    1990-01-01T23:59:59.000Z

    A system for starting an arc for welding uses three DC power supplies, a high voltage supply for initiating the arc, an intermediate voltage supply for sustaining the arc, and a low voltage welding supply directly connected across the gap after the high voltage supply is disconnected.

  11. Laser assisted arc welding for aluminum alloys

    SciTech Connect (OSTI)

    Fuerschbach, P.W.

    2000-01-01T23:59:59.000Z

    Experiments have been performed using a coaxial end-effector to combine a focused laser beam and a plasma arc. The device employs a hollow tungsten electrode, a focusing lens, and conventional plasma arc torch nozzles to co-locate the focused beam and arc on the workpiece. Plasma arc nozzles were selected to protect the electrode from laser generated metal vapor. The project goal is to develop an improved fusion welding process that exhibits both absorption robustness and deep penetration for small scale (<1.5 mm thickness) applications. On aluminum alloys 6061 and 6111, the hybrid process has been shown to eliminate hot cracking in the fusion zone. Fusion zone dimensions for both stainless steel and aluminum were found to be wider than characteristic laser welds, and deeper than characteristic plasma arc welds.

  12. Effect of heat input on the microstructure and mechanical properties of tungsten inert gas arc butt-welded AZ61 magnesium alloy plates

    SciTech Connect (OSTI)

    Min Dong [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Shen Jun, E-mail: shenjun2626@163.com [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Lai Shiqiang; Chen Jie [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2009-12-15T23:59:59.000Z

    In this paper, the effects of heat input on the microstructures and mechanical properties of tungsten inert gas arc butt-welded AZ61 magnesium alloy plates were investigated by microstructural observations, microhardness tests and tensile tests. The results show that with an increase of the heat input, the grains both in the fusion zone and the heat-affected zone coarsen and the width of the heat-affected zone increased. Moreover, an increase of the heat input resulted in a decrease of the continuous {beta}-Mg{sub 17}Al{sub 12} phase and an increase of the granular {beta}-Mg{sub 17}Al{sub 12} phase in both the fusion zone and the heat-affected zone. The ultimate tensile strength of the welded joint increased with an increase of the heat input, while, too high a heat input resulted in a decrease of the ultimate tensile strength of the welded joint. In addition, the average microhardness of the heat-affected zone and fusion zone decreased sharply with an increase of the heat input and then decreased slowly at a relatively high heat input.

  13. Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D

    E-Print Network [OSTI]

    Zhou, Wei

    Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D W. Zhou*, T. Z. Long and C. K of the plates were produced using tungsten inert gas (TIG) welding method. The TIG arc was also used to deposit welding beads on some of the thin plates. No cracking was found in the butt joints. However, hot cracking

  14. Three-dimensional modeling of the plasma arc in arc welding

    SciTech Connect (OSTI)

    Xu, G.; Tsai, H. L. [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, 1870 Miner Circle, Rolla, Missouri 65409 (United States); Hu, J. [Department of Mechanical Engineering, University of Bridgeport, Bridgeport, Connecticut 06604 (United States)

    2008-11-15T23:59:59.000Z

    Most previous three-dimensional modeling on gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) focuses on the weld pool dynamics and assumes the two-dimensional axisymmetric Gaussian distributions for plasma arc pressure and heat flux. In this article, a three-dimensional plasma arc model is developed, and the distributions of velocity, pressure, temperature, current density, and magnetic field of the plasma arc are calculated by solving the conservation equations of mass, momentum, and energy, as well as part of the Maxwell's equations. This three-dimensional model can be used to study the nonaxisymmetric plasma arc caused by external perturbations such as an external magnetic field. It also provides more accurate boundary conditions when modeling the weld pool dynamics. The present work lays a foundation for true three-dimensional comprehensive modeling of GTAW and GMAW including the plasma arc, weld pool, and/or electrode.

  15. Oxygen and Nitrogen Contamination During Arc Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) ) : ,- Oxygen and Nitrogen Contamination During Arc Welding T. W. Eagar Department of }faterials, shielded metal arc, self-shielded metal arc, and submerged arc welding are reviewed. Calcu- lations upon heating is also discussed. Introduction Oxygen and nitrogen ~ontamination of weld metal

  16. Percussive arc welding apparatus

    DOE Patents [OSTI]

    Hollar, Jr., Donald L. (Overland Park, KS)

    2002-01-01T23:59:59.000Z

    A percussive arc welding apparatus includes a generally cylindrical actuator body having front and rear end portions and defining an internal recess. The front end of the body includes an opening. A solenoid assembly is provided in the rear end portion in the internal recess of the body, and an actuator shaft assembly is provided in the front end portion in the internal recess of the actuator body. The actuator shaft assembly includes a generally cylindrical actuator block having first and second end portions, and an actuator shaft having a front end extending through the opening in the actuator body, and the rear end connected to the first end portion of the actuator block. The second end portion of the actuator block is in operational engagement with the solenoid shaft by a non-rigid connection to reduce the adverse rebound effects of the actuator shaft. A generally transversely extending pin is rigidly secured to the rear end of the shaft. One end of the pin is received in a slot in the nose housing sleeve to prevent rotation of the actuator shaft during operation of the apparatus.

  17. ABSTRACT. Keyhole plasma arc welding is a unique arc welding process for deep

    E-Print Network [OSTI]

    Zhang, YuMing

    ABSTRACT. Keyhole plasma arc welding is a unique arc welding process for deep penetration. To ensure the quality of the welds, the presence of the keyhole is crit- ical. Understanding of the keyhole will certainly benefit the improvement of the process and weld quality. Currently, the size of the keyhole

  18. High-power laser and arc welding of thorium-doped iridium alloys

    SciTech Connect (OSTI)

    David, S.A.; Liu, C.T.

    1980-05-01T23:59:59.000Z

    The arc and laser weldabilities of two Ir-0.3% W alloys containing 60 and 200 wt ppM Th have been investigated. The Ir-.03% W alloy containing 200 wt ppM Th is severely prone to hot cracking during gas tungsten-arc welding. Weld metal cracking results from the combined effects of heat-affected zone liquation cracking and solidification cracking. Scanning electron microscopic analysis of the fractured surface revealed patches of low-melting eutectic. The cracking is influenced to a great extent by the fusion zone microstructure and thorium content. The alloy has been welded with a continuous-wave high-power CO/sub 2/ laser system with beam power ranging from 5 to 10 kW and welding speeds of 8 to 25 mm/s. Successful laser welds without hot cracking have been obtained in this particular alloy. This is attributable to the highly concentrated heat source available in the laser beam and the refinement in fusion zone microstructure obtained during laser welding. Efforts to refine the fusion zone structure during gas tungsten-arc welding of Ir-0.3 % W alloy containing 60 wt ppM Th were partially successful. Here transverse arc oscillation during gas tungsten-arc welding refines the fusion zone structure to a certain extent. However, microstructural analysis of this alloy's laser welds indicates further refinement in the fusion zone microstructure than in that from the gas tungsten-arc process using arc oscillations. The fusion zone structure of the laser weld is a strong function of welding speed.

  19. Method for controlling gas metal arc welding

    DOE Patents [OSTI]

    Smartt, Herschel B. (Idaho Falls, ID); Einerson, Carolyn J. (Idaho Falls, ID); Watkins, Arthur D. (Idaho Falls, ID)

    1989-01-01T23:59:59.000Z

    The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections.

  20. Method for controlling gas metal arc welding

    DOE Patents [OSTI]

    Smartt, H.B.; Einerson, C.J.; Watkins, A.D.

    1987-08-10T23:59:59.000Z

    The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections. 3 figs., 1 tab.

  1. NEW NUMERICAL TECHNOLOGIES FOR THE SIMULATION OF ARC WELDING PROCESSES

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    NEW NUMERICAL TECHNOLOGIES FOR THE SIMULATION OF ARC WELDING PROCESSES Michel Bellet 1 , Makhlouf Antipolis, France; soudage@transvalor.com Keywords: welding, finite elements, material deposit, adaptive for arc welding simulation and analysis. The new numerical technologies essentially consist first

  2. IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 50, NO. 3, JUNE 2001 697 Robust Sensing of Arc Length

    E-Print Network [OSTI]

    Zhang, YuMing

    the distribution of the arc energy and thus the heat input and width of the weld. This work aims at improving research and equipment development. The gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW tungsten arc welding (GTAW) with argon shield. To this end, effects of welding parame- ters on spectral

  3. What makes an electric welding arc perform its required function

    SciTech Connect (OSTI)

    Correy, T.B.

    1982-09-01T23:59:59.000Z

    The physics of direct current and alternating current welding arcs, the heat transfer of direct current welding arcs, the characteristics of dc welding and ac welding power supplies and recommendations for the procurement and maintenance of precision power supplies are discussed. (LCL)

  4. Plasma transferred arc repair welding of the nickel-base superalloy IN-738LC

    SciTech Connect (OSTI)

    Su, C.Y.; Chou, C.P. [National Chiao Tung Univ., Hsinchu (Taiwan, Province of China). Dept. of Mechanical Engineering; Wu, B.C.; Lih, W.C. [Industrial Technology Research Inst., Hsinchu (Taiwan, Province of China). Materials Research Labs.

    1997-10-01T23:59:59.000Z

    Plasma transferred arc welding (PTA) has been considered a promising process to restore worn areas of land-based gas turbine blades and vanes. The objective of this investigation was to study the effect of PTA welding on the repairing of IN-738LC superalloy components. Tensile tests were conducted on specimens welded with various combinations of parameters. Room temperature, 760 C, and 980 C were selected as tensile test temperatures. High-temperature phase transformed, during solidification, were identified by differential thermal analysis (DTA). The weld-pool shapes and microstructures of welded specimens prepared by various welding parameters were evaluated by optical metallography (OM), a scanning electron microscope (SEM) equipped with energy dispersive x-ray spectrometer (EDS), and microhardness testing. Results of this study showed that PTA welded specimens exhibited 96% nominal tensile strength of IN-738LC base materials. Specimen failure was observed predominantly in the base materials instead of in the heat-affected zone (HAZ) for gas tungsten arc weld (GTAW) repair weldments. IN-738LC is considered susceptible to weld cracking during fusion welding; however, using a low-input repair welding process (PTA), cracking susceptibility could be minimized by the optimized welding parameters.

  5. Costing of Joining Methods -Arc Welding Costs

    E-Print Network [OSTI]

    Colton, Jonathan S.

    Costing of Joining Methods - Arc Welding Costs ver. 1 ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 1 #12;OverviewOverview · Cost components · Estimation of costsEstimation of costs · Examples ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 2 #12;Cost

  6. WELDING RESEARCH -s11WELDING JOURNAL

    E-Print Network [OSTI]

    Zhang, YuMing

    WELDING RESEARCH -s11WELDING JOURNAL ABSTRACT. Double-electrode gas metal arc welding (DE-GMAW) is a novel weld- ing process recently developed to increase welding productivity while maintaining the base its non- consumable tungsten electrode with a consumable welding wire electrode result- ing in a new

  7. Welding : arc-welded joints in aluminium and its alloys : quality levels for imperfections : technical corrigendum 1

    E-Print Network [OSTI]

    International Organization for Standardization. Geneva

    2006-01-01T23:59:59.000Z

    Welding : arc-welded joints in aluminium and its alloys : quality levels for imperfections : technical corrigendum 1

  8. automatic arc welding: Topics by E-print Network

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

    control computer, has been accomplished. n.n. 2 Double-Sided Arc Welding Increases Weld Joint Penetration CiteSeer Summary: this paper proposes increasing the penetration by...

  9. Thermocapillary and arc phenomena in stainless steel welds

    SciTech Connect (OSTI)

    Pierce, S.W.

    1993-10-01T23:59:59.000Z

    Goal was to study effect of power level and distribution on thermocapiilary-induced weld shape and of arc factors on weld shape. Thermocapillarity was apparent in both conduction mode EB welds and GTA welds, particularly in the former. A non-Gaussian arc distribution is suggested for accounting for the differences between the twoss processes. At higher current levels (200--300 A), plasma shear force also contributes to weld shape development. Evidence suggests that thermocapillary flow reversal is not a factor in normal GTA welds; EDB flow reversal occurs only at high power density levels where the keyhole mode is present.

  10. Specification and qualification of welding procedures for metallic materials : Welding procedure test : Part 2: Arc welding of aluminium and its alloys

    E-Print Network [OSTI]

    International Organization for Standardization. Geneva

    2005-01-01T23:59:59.000Z

    Specification and qualification of welding procedures for metallic materials : Welding procedure test : Part 2: Arc welding of aluminium and its alloys

  11. Specification and qualification of welding procedures for metallic materials : Welding procedure test : Part 2: Arc welding of aluminium and its alloys : technical corrigendum 1

    E-Print Network [OSTI]

    International Organization for Standardization. Geneva

    2005-01-01T23:59:59.000Z

    Specification and qualification of welding procedures for metallic materials : Welding procedure test : Part 2: Arc welding of aluminium and its alloys : technical corrigendum 1

  12. arc welding automation: Topics by E-print Network

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

    arc welding automation First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Double-Sided Arc Welding...

  13. THE PHYSICS OF ARC WELDING PROCESSES Department of Materials Science and Engineering,

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) THE PHYSICS OF ARC WELDING PROCESSES T.W.EAGAR Department of Materials Science and Engineering, Massachusetts Institute of Technology Abstract Welding is an extremely complex proce ss; however, due to its Wor ds: Arc Welding, Arc Physics, Shielding Gases, Gas Metal Arc Welding. 1. Introduction Langmuir

  14. Characterization of Gas Metal Arc Welding welds obtained with new high Cr-Mo ferritic stainless steel filler wires

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Characterization of Gas Metal Arc Welding welds obtained with new high Cr-Mo ferritic stainless Several compositions of metal cored filler wire were manufactured to define the best welding conditions for homogeneous welding, by Gas Metal Arc Welding (GMAW) process, of a modified AISI 444 ferritic stainless steel

  15. ~.,Slag-Metal Equilibrium During Submerged e-~~ Arc Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ~~ . ~.·,Slag-Metal Equilibrium During Submerged ·e-~~ Arc Welding C. S. CHAI AND T. W. EAGAR A thermodynamic model of the equilibria existing between the slag and the weld metal during submerged arc welding over forty years ago, submerged arc welding has developed into one of the most efficient, most reliable

  16. Modelling of the bead formation during multi pass hybrid laser/gas metal arc welding

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    - 1 - Modelling of the bead formation during multi pass hybrid laser/gas metal arc welding Olivier dimensional finite element model has been developed to simulate weld bead formation in multi pass hybrid laser/gas metal arc welding. The model considers both a gas metal arc welding (GMAW) electrode and a laser beam

  17. Gas Metal Arc Welding Process Modeling and Prediction of Weld Microstructure in MIL A46100 Armor-Grade

    E-Print Network [OSTI]

    Grujicic, Mica

    Gas Metal Arc Welding Process Modeling and Prediction of Weld Microstructure in MIL A46100 Armor metal arc welding (GMAW) butt-joining process has been modeled using a two-way fully coupled, transient in the form of heat, and the mechanical material model of the workpiece and the weld is made temperature

  18. Numerical modelling of hybrid arc/laser welding: a Level Set approach for weld bead formation and residual stresses

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Numerical modelling of hybrid arc/laser welding: a Level Set approach for weld bead formation.Bellet@mines-paristech.fr ABSTRACT The joining of high thickness steel sheets by means of hybrid Laser/GMAW welding processes of the workpiece borders. Two finite elements models are presented to illustrate: (i) A hybrid arc/laser welding

  19. Optical emission spectroscopy of metal vapor dominated laser-arc hybrid welding plasma

    SciTech Connect (OSTI)

    Ribic, B.; DebRoy, T. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Burgardt, P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2011-04-15T23:59:59.000Z

    During laser-arc hybrid welding, plasma properties affect the welding process and the weld quality. However, hybrid welding plasmas have not been systematically studied. Here we examine electron temperatures, species densities, and electrical conductivity for laser, arc, and laser-arc hybrid welding using optical emission spectroscopy. The effects of arc currents and heat source separation distances were examined because these parameters significantly affect weld quality. Time-average plasma electron temperatures, electron and ion densities, electrical conductivity, and arc stability decrease with increasing heat source separation distance during hybrid welding. Heat source separation distance affects these properties more significantly than the arc current within the range of currents considered. Improved arc stability and higher electrical conductivity of the hybrid welding plasma result from increased heat flux, electron temperatures, electron density, and metal vapor concentrations relative to arc or laser welding.

  20. A dimensionless parameter model for arc welding processes

    SciTech Connect (OSTI)

    Fuerschbach, P.W.

    1994-12-31T23:59:59.000Z

    A dimensionless parameter model previously developed for C0{sub 2} laser beam welding has been shown to be applicable to GTAW and PAW autogenous arc welding processes. The model facilitates estimates of weld size, power, and speed based on knowledge of the material`s thermal properties. The dimensionless parameters can also be used to estimate the melting efficiency, which eases development of weld schedules with lower heat input to the weldment. The mathematical relationship between the dimensionless parameters in the model has been shown to be dependent on the heat flow geometry in the weldment.

  1. Control Engineering Practice 11 (2003) 14011411 Modeling and control of quasi-keyhole arc welding process

    E-Print Network [OSTI]

    Zhang, YuMing

    Control Engineering Practice 11 (2003) 1401­1411 Modeling and control of quasi-keyhole arc welding to operate the keyhole arc welding process. Because the method's effectiveness depends on the amperage reserved. Keywords: Modeling; Predictive control; Manufacturing; Welding 1. Introduction Keyhole arc

  2. CHANGES IN SOLIDIFICATION MODE, AND THE MEASUREMENT OF COOLING RATES FOLLOWING SOLIDIFICATION DURING ARC WELDING

    E-Print Network [OSTI]

    Cambridge, University of

    SOLIDIFICATION DURING ARC WELDING 2.1 INTRODUCTION The solidification process in a weld pool has been shown to have a considerable in- fluence upon the properties of the resultant weld. It influences elements, and hence the homogeneity of the weld. Previous work on the cooling behaviour of welds (Garland

  3. Direct Modeling of Material Deposit and Identification of Energy Transfer in Gas Metal Arc Welding

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Direct Modeling of Material Deposit and Identification of Energy Transfer in Gas Metal Arc Welding sources for finite element simulation of gas metal arc welding (GMAW). Design for the modeling of metal deposition results in a direct calculation of the formation of the weld bead, without any

  4. ~DELING OF METAL TRANSFKR IN GAS METAL ARC WELDING Yong -Seog Kim and T. W. Eagar

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) ) ) ~DELING OF METAL TRANSFKR IN GAS METAL ARC WELDING Yong -Seog Kim and T. W. Eagar theory and the pinch i ns t a bility theor y as a function of welding cur rent . Experimental of the gas metal arc process in the late 1940s, it has become one of the most important welding processes

  5. A COUPLED APPROACH FOR THE MODELLING OF ARC WELDING Christel Pequet1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    A COUPLED APPROACH FOR THE MODELLING OF ARC WELDING PROCESSES Christel Pequet1 , Patrice Lasne1 ; email : michel.bellet@ensmp.fr Keywords: welding, finite elements, thermal arising in arc welding as well as their interaction: heat input, metal deposit, solidification, phase

  6. Heat and Metal Transfer in Gas Metal Arc Welding Using Argon and Helium

    E-Print Network [OSTI]

    Eagar, Thomas W.

    Heat and Metal Transfer in Gas Metal Arc Welding Using Argon and Helium P.G. JONSSON, T.W. EAGAR transfer in gas metal arc welding (GMAW) of mild steel using argon and helium shielding gases. Major dif properties. Various findings from the study include that an arc cannot be stru~k in a pure helium atmosphere

  7. Effect of hydrogen in an argon GTAW shielding gas: Arc characteristics and bead morphology

    SciTech Connect (OSTI)

    Onsoeien, M.; Olson, D.L.; Liu, S. (Colorado School of Mines, Golden, CO (United States). Center for Welding and Joining Research); Peters, R. (Delft Technological Univ. (Netherlands))

    1995-01-01T23:59:59.000Z

    The influence of hydrogen additions to an argon shielding gas on the heat input and weld bead morphology was investigated using the gas tungsten arc welding process. Variations in weld bead size and shape with hydrogen additions were related to changes in the ability of the arc to generate heat and not to generate perturbations in the weld pool caused by Marangoni fluid flow.

  8. Welding Development W87 Baseline

    SciTech Connect (OSTI)

    A. Newman; G. Gibbs; G. K. Hicken

    1998-11-01T23:59:59.000Z

    This report covers the development activities used to qualify the Gas Tungsten Arc (FTA) girth weld and the resistance stem attachments on the W87 Base Line (W87BL). Design of experiments was used throughout the development activities.

  9. Method and device for reducing overpenetration at the start of plasma arc welds

    DOE Patents [OSTI]

    Sanders, John M. (Jackson Township, Stark County, OH); Lehmann, John M. (Bedford County, VA); Ryan, Patrick M. (Washington Township, Stark County, OH)

    1998-01-01T23:59:59.000Z

    A shim for improving plasma arc weld quality has ends tapered at about 25.degree. and notches at each end roughly centered over the corner between the tapered ends and main body of the shim. The improved shim allows lower starting plasma arc heat input and reduces the occurrence of sagging, or overpenetration, of the weld.

  10. METAL TRANSFER CONTROL IN GAS METAL ARC WELDING L.A. Jones, T.W. Eagar, J.H. Lang

    E-Print Network [OSTI]

    Eagar, Thomas W.

    METAL TRANSFER CONTROL IN GAS METAL ARC WELDING L.A. Jones, T.W. Eagar, J.H. Lang Massachusetts Institute of Technology Cambridge, MA 02139 USA Abstract Power input to the arc in gas metal arc welding to decouple these processes. Methods to achieve this decoupling are discussed. Pulsed-power welding is widely

  11. Improved Microstructure and Properties of 6061 Aluminum Alloy Weldments Using a Double-Sided Arc Welding

    E-Print Network [OSTI]

    Zhang, YuMing

    Welding Process Y.M. ZHANG, C. PAN, and A.T. MALE Due to its popularity and high crack sensitivity, 6061 aluminum alloy was selected as a test material for the newly developed double-sided arc welding (DSAW systematically. The percentage of fine equiaxed grains in the fully penetrated welds is greatly increased

  12. Computational Modeling of Microstructural-Evolution in AISI 1005 Steel During Gas Metal Arc Butt Welding

    E-Print Network [OSTI]

    Grujicic, Mica

    Welding M. Grujicic, S. Ramaswami, J.S. Snipes, R. Yavari, A. Arakere, C.-F. Yen, and B.A. Cheeseman-mechanical finite-element procedure is developed to model conventional gas metal arc welding (GMAW) butt of the workpiece and the weld temperature- dependent and by allowing the potential work of plastic deformation

  13. EFFECTS OF SURFACE DEPRESSION AND CONVECTION IN GTA WELDING

    E-Print Network [OSTI]

    Eagar, Thomas W.

    EFFECTS OF SURFACE DEPRESSION AND CONVECTION IN GTA WELDING M.L. Lin, T.W. Eagar Materials of the weld pool which are changed by these fact ors . It is shown that, at current s in excess of 300 amperes in a different heat distribution on the weld pool surface . ALTHOUGH THE GAS tungsten arc (GTA) welding process

  14. The modelling of irradiation embrittlement in submerged-arc welds

    SciTech Connect (OSTI)

    Bolton, C.J.; Buswell, J.T.; Jones, R.B.; Moskovic, R.; Priest, R.H. [Nuclear Electric plc, Berkeley (United Kingdom). Berkeley Technology Centre

    1996-12-31T23:59:59.000Z

    Until very recently, the irradiation embrittlement behavior of submerged-arc welds has been interpreted in terms of two mechanisms, namely a matrix damage component and an additional component due to the irradiation-enhanced production of copper-rich precipitates. However, some of the weld specimens from a recent accelerated re-irradiation experiment have shown high Charpy shifts which exceeded the values expected from the measured shift in yield stress. Microstructural examination has revealed the occurrence of intergranular fracture (IGF) in these specimens, accompanied by grain boundary segregation of phosphorus. Theoretical models were developed to predict the parametric dependence of irradiation-enhanced phosphorus segregation on experimental variables. Using these parametric forms, along with the concept of a critical level of segregation for the onset of IGF instead of cleavage, a three mechanism trend curve has been developed. The form of this trend curve, taking into account IGF as well as matrix and copper embrittlement, is thus mechanistically based. The constants in the equation, however, are obtained by a statistical fit to the actual Charpy shift database.

  15. Stainless steel submerged arc weld fusion line toughness

    SciTech Connect (OSTI)

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

    1995-04-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Eagar, Thomas W.

    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

  17. The Size of the Sensitization Zone in 304 Stainless Steel Welds

    E-Print Network [OSTI]

    Eagar, Thomas W.

    . Single-pass, bead-on-plate welds were made by gas tungsten arc welding on 30-cm/30-cm/ 1.3-cm 304 that the width of the sensitization zone is in proportion to the magnitude ofthe heat input, except when very heat distrihution. Under certain welding conditions, one can obwin welds which are free ofsensitization

  18. Materials and Design 50 (2013) 38-43 Regeneration Technique for Welding Nanostructured Bainite

    E-Print Network [OSTI]

    Cambridge, University of

    2013-01-01T23:59:59.000Z

    by spark wire cutting. Bead-on-plate welds with autogenous gas tungsten arc welding were perform by the heat input during welding, from transforming into brittle martensite. The microstructures of the fusion to the formation of brittle, untempered martensite. Hong et al. [6] attempted a rapid post-weld heat treatment

  19. Improvement of reliability of welding by in-process sensing and control (development of smart welding machines for girth welding of pipes). Final report

    SciTech Connect (OSTI)

    Hardt, D.E.; Masubuchi, K.; Paynter, H.M.; Unkel, W.C.

    1983-04-01T23:59:59.000Z

    Closed-loop control of the welding variables represents a promising, cost-effective approach to improving weld quality and therefore reducing the total cost of producing welded structures. The ultimate goal is to place all significant weld variables under direct closed-loop control; this contrasts with preprogrammed machines which place the welding equipment under control. As the first step, an overall strategy has been formulated and an investigation of weld pool geometry control for gas tungsten arc process has been completed. The research activities were divided into the areas of arc phenomena, weld pool phenomena, sensing techniques and control activities.

  20. Multiphysics Modeling and Simulations of Mil A46100 Armor-Grade Martensitic Steel Gas Metal Arc Welding

    E-Print Network [OSTI]

    Grujicic, Mica

    Welding Process M. Grujicic, S. Ramaswami, J.S. Snipes, C.-F. Yen, B.A. Cheeseman, and J.S. Montgomery developed for the conventional Gas Metal Arc Welding (GMAW) joining process and used to analyze butt-welding modules, each covering a specific aspect of the GMAW process, i.e., (a) dynamics of welding-gun behavior

  1. THE REMOVAL OF CARBON/BEUTERIUM FROM STAINLESS STEEL AND TUNGSTEN BY TRANSFERRED-ARC CLEANING

    SciTech Connect (OSTI)

    K. J. HOLLIS; R. G. CASTRO; ET AL

    2001-04-01T23:59:59.000Z

    Tungsten and stainless steel samples have been contaminated with deuterium and carbon to simulate deposited layers in magnetic-confinement fusion devices. Deuterium and carbon were co-deposited onto the sample surfaces using a deuterium plasma seeded with varying amounts of deuterated methane. Deuterium was also implanted into the samples in an accelerator to simulate hydrogen isotope ion implantation conditions in magnetic confinement fusion devices. Cathodic arc, or transferred-arc (TA) cleaning was employed to remove the deposits from the samples. The samples were characterized by ion beam analysis both before and after cleaning to determine deuterium and carbon concentrations present. The deuterium content was greatly reduced by the cleaning thus demonstrating the possibility of using the TA cleaning technique for removing deuterium and/or tritium from components exposed to D-T fuels. Removal of surface layers and significant reduction of subsurface carbon concentrations was also observed.

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

    E-Print Network [OSTI]

    Keehan, Enda

    2004-01-01T23:59:59.000Z

    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...

  3. A two-dimensional thermomechanical simulation of a gas metal arc welding process

    SciTech Connect (OSTI)

    Ortega, A.R.

    1990-08-01T23:59:59.000Z

    A low heat input gas metal arc (GMA) weld overlay process is being investigated as a possible means to repair Savannah River nuclear reactor tanks in the event cracks are detected in the reactor walls. Two-dimensional thermomechanical simulations of a GMA welding process were performed using the finite element code ABAQUS to assist in the design of the upcoming weld experiments on helium-charged specimens. The thermal model correlated well with existing test data, i.e., fusion zone depth and thermocouple data. In addition, numerical results revealed that after cool-down the final deformation of the workpiece was qualitatively similar to the shape observed experimentally. Based on these analyses, conservative recommendations were made for the workpiece dimensions, weld pass spacing, and thermomechanical boundary conditions to ensure the experiments would be as representative as possible of welding on the reactor walls. 12 refs., 13 figs.

  4. Numerical Analysis of Metal Transfer in Gas Metal Arc Welding under Modified Pulsed Current Conditions

    E-Print Network [OSTI]

    Zhang, YuMing

    causes a thermal load too high to apply to thin sectioned or heat-sensitive materials. In an effort was assumed as the boundary condition for the calculation of the electromagnetic force. The calculations were agreement between calculation and experimental results. I. INTRODUCTION IN gas metal arc welding (GMAW

  5. arc welding dynamic: Topics by E-print Network

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

    Materials Science Websites Summary: diffusivity specific heat thermal conductivity 2 operating parameter (n qv 4a p Tc - T0 net heat i nput- CHANGES OF WELD POOL SHAPE BY...

  6. arc welding electrodes: Topics by E-print Network

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

    S 2010-01-01 99 Resistance Spot Welding Characteristic of Ferrite-Martensite DP600 Dual Phase Advanced High Strength Steel-Part III: Mechanical Properties CiteSeer Summary:...

  7. arc welding material: Topics by E-print Network

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

    remeshing. The heat for the modeling of metal deposition results in a direct calculation of the formation of the weld bead, without any Paris-Sud XI, Universit de 2...

  8. Plutonium metal and oxide container weld development and qualification

    SciTech Connect (OSTI)

    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

    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.``

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

    SciTech Connect (OSTI)

    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

    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.

  10. Contrib. Plasma Phys. 51, No. 2-3, 293 296 (2011) / DOI 10.1002/ctpp.201000061 LTE Experimental Validation in a Gas Metal Arc Welding Plasma

    E-Print Network [OSTI]

    2011-01-01T23:59:59.000Z

    Validation in a Gas Metal Arc Welding Plasma Column F. Valensi1,2 , S. Pellerin1 , A. Boutaghane3 , K, France 7 CTAS-Air Liquide Welding, Saint Ouen l'Aum^one, 95315 Cergy-Pontoise cedex, France Received 12 Spectroscopy, Boltzmann Plot, Sola method, LTE. During gas metal arc welding (GMAW), the plasma obtained has

  11. Narrow gap welding with the hot wire GTA process

    SciTech Connect (OSTI)

    Cook, G.E.; Levick, P.C.

    1985-08-01T23:59:59.000Z

    Narrow gap welding offers the promise of dramatically improved weld completion rates and reduced heat input for welding of butt joints in materials of 10 mm (0.4 in.) section thickness and larger. Techniques for successful welding of narrow gap joint preparations have been discussed in the literature for approximately twenty years, with the majority of these based on the consumable electrode processes. Gas tungsten arc welding with cold wire filler addition has been shown to be capable of narrow gap welding although limited deposition rate capability has not made this a competitive alternative. The GTAW process offers the advantages of superior penetration control for one-sided welding of butt joints, as well as the potential for reducing incomplete fusion defects. The addition of hot wire filler metal to the gas tungsten arc provides an attractive alternative that combines high deposition rate capability and independent control of heat input.

  12. Video Game Device Haptic Interface for Robotic Arc Welding

    SciTech Connect (OSTI)

    Corrie I. Nichol; Milos Manic

    2009-05-01T23:59:59.000Z

    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.

  13. Computer modeling of arc welds to predict effects of critical variables on weld penetration

    SciTech Connect (OSTI)

    Zacharia, T.; David, S.A.

    1991-01-01T23:59:59.000Z

    In recent years, there have been several attempts to study the effect of critical variables on welding by computational modeling. It is widely recognized that temperature distributions and weld pool shapes are keys to quality weldments. It would be very useful to obtain relevant information about the thermal cycle experienced by the weld metal, the size and shape of the weld pool, and the local solidification rates, temperature distributions in the heat-affected zone (HAZ), and associated phase transformations. The solution of moving boundary problems, such as weld pool fluid flow and heat transfer, that involve melting and/or solidification is inherently difficult because the location of the solid-liquid interface is not known a priori and must be obtained as a part of the solution. Because of non-linearity of the governing equations, exact analytical solutions can be obtained only for a limited number of idealized cases. Therefore, considerable interest has been directed toward the use of numerical methods to obtain time-dependant solutions for theoretical models that describe the welding process. Numerical methods can be employed to predict the transient development of the weld pool as an integral part of the overall heat transfer conditions. The structure of the model allows each phenomenon to be addressed individually, thereby gaining more insight into their competing interactions. 19 refs., 6 figs., 1 tab.

  14. Investigation of arc length versus flange thickness while using an arc voltage controller

    SciTech Connect (OSTI)

    Daumeyer, G.J.

    1994-11-01T23:59:59.000Z

    An arc voltage controller (AVC) for gas tungsten arc welding will change arc length when flange thickness changes while all other variables, including AVC setting, are held constant. A procedure for calibrating an LVDT (linear variable displacement transducer) used for electrode assembly motion monitoring was proven for laboratory setups and special investigations. A partial characterization on the deadband and sensitivity control settings of the Cyclomatic AVC was completed.

  15. The dynamics of droplet formation and detachment in gas metal arc welding

    SciTech Connect (OSTI)

    Johnson, J.A.; Smartt, H.B.; Clark, D.E.; Carlson, N.M.; Watkins, A.D.; Lethcoe, B.J.

    1990-01-01T23:59:59.000Z

    Experimental measurements of gas metal arc welding are required for the development and confirmation of models of the process. This paper reports on two experiments that provide information for models of the arc physics and of the weld pool dynamics. The heat transfer efficiency of the spray transfer mode in gas metal arc welding was measured using a calorimetry technique. The efficiency varied from 75 to 85%. A special fixture was used to measure the droplet contribution, which is determined to be between 35 and 45% of the total input energy. A series of experiments was performed at a variety of conditions ranging from globular to spray to streaming transfer. The transfer was observed by taking high-speed movies at 500 to 5000 frames per second of the backlighted droplets. An automatic image analysis system was used to obtain information about the droplets including time between detachments, droplet size, and droplet acceleration. At the boundary between the globular and spray modes, the droplet size varies between small droplets that melt off faster than average, resulting in a smaller electrode extension, and large droplets that melt off slower than average, resulting in an increase in the electrode extension. 5 refs., 4 figs., 2 tabs.

  16. Reasons for superior mechanical and corrosion properties of 2219 aluminum alloy electron beam welds

    SciTech Connect (OSTI)

    Koteswara Rao, S.R. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Madras, Chennai-600 036 (India)]. E-mail: sajjarkr@yahoo.com; Madhusudhan Reddy, G. [Defense Metallurgical Research Laboratory, Hyderabad-500 058 (India); Srinivasa Rao, K. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Madras, Chennai-600 036 (India); Kamaraj, M. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Madras, Chennai-600 036 (India); Prasad Rao, K. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Madras, Chennai-600 036 (India)

    2005-11-15T23:59:59.000Z

    Electron beam welds of aluminum alloy 2219 offer much higher strength compared to gas tungsten arc welds of the same alloy and the reasons for this have not been fully explored. In this study both types of welds were made and mechanical properties were evaluated by tensile testing and pitting corrosion resistance by potentio dynamic polarization tests. It is shown that electron beam welds exhibit superior mechanical and corrosion properties. The weld metals have been characterized by scanning electron microscopy; transmission electron microscopy and electron probe micro analysis. Presence of partially disintegrated precipitates in the weld metal, finer micro porosity and uniform distribution of copper in the matrix were found to be the reasons for superior properties of electron beam welds apart from the fine equiaxed grain structure. Transmission electron micrographs of the heat affected zones revealed the precipitate disintegration and over aging in gas tungsten arc welds.

  17. WELDING RESEARCH -s229WELDING JOURNAL

    E-Print Network [OSTI]

    Zhang, YuMing

    WELDING RESEARCH -s229WELDING JOURNAL ABSTRACT. Dual-bypass gas metal arc welding (DB agrees with experimental data. Introduction Gas metal arc welding (GMAW) is an arc welding process- minum alloy welded structures have been widely applied. The use of aluminum as an alternative material

  18. Fusion-bonded epoxy coating defects on weld center line of submerged-arc welded pipe

    SciTech Connect (OSTI)

    Sokol, D.R.; Herndon, C.M. (Tenneco Oil Co., Houston, TX (USA))

    1990-08-01T23:59:59.000Z

    The problem of weld center line coating defects in fusion-bonded epoxy coatings has occurred on pipe produced in Europe, North America, and Asia. At various times, the defects have been attributed to coating application practices, powder manufacturing, pipe manufacturing, welding methods, and overly critical inspectors. This article details plant experience and experimental trails that led to the identification of the cause and proof of the solution. The ultimate effect of initial coating defects on cathodic protection requirements is a matter of concern also.

  19. Repair welding of fusion reactor components

    SciTech Connect (OSTI)

    Chin, B.A.

    1993-05-15T23:59:59.000Z

    Experiments have shown that irradiated Type 316 stainless steel is susceptible to heat-affected-zone (HAZ) cracking upon cooling when welded using the gas tungsten arc (GTA) process under lateral constraint. The cracking has been hypothesized to be caused by stress-assisted helium bubble growth and rupture at grain boundaries. This study utilized an experimental welding setup which enabled different compressive stresses to be applied to the plates during welding. Autogenous GTA welds were produced in Type 316 stainless steel doped with 256 appm helium. The application of a compressive stress, 55 MPa, during welding suppressed the previously observed catastrophic cracking. Detailed examinations conducted after welding showed a dramatic change in helium bubble morphology. Grain boundary bubble growth along directions parallel to the weld was suppressed. Results suggest that stress-modified welding techniques may be used to suppress or eliminate helium-induced cracking during joining of irradiated materials.

  20. Plasma diagnostics in gas metal arc welding by optical emission spectroscopy This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Plasma diagnostics in gas metal arc welding by optical emission spectroscopy This article has been welding by optical emission spectroscopy F Valensi1,2 , S Pellerin1 , A Boutaghane3 , K Dzierzega4 de Bourges), BP 4043, 18028 Bourges cedex, France 7 CTAS-Air Liquide Welding, Saint Ouen l

  1. Narrow groove welding gas diffuser assembly and welding torch

    DOE Patents [OSTI]

    Rooney, Stephen J. (East Berne, NY)

    2001-01-01T23:59:59.000Z

    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.

  2. Method for enhanced control of welding processes

    DOE Patents [OSTI]

    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

    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.

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

    SciTech Connect (OSTI)

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

    1994-12-31T23:59:59.000Z

    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.

  4. Department of Industrial Engineering Spring 2013 Corle Building Systems Submerged Arc Welding Machine

    E-Print Network [OSTI]

    Demirel, Melik C.

    Welding Machine Overview Due to the location of the two weld heads with respect to the ground shoes, the machine is unable to weld approximately the first 16 inches and final 12 inches of the I-beam. These sections must be hand welded later in the fabrication process. This hand welding process is inefficient

  5. Technique to eliminate helium induced weld cracking in stainless steels

    SciTech Connect (OSTI)

    Chin-An Wang; Chin, B.A. [Auburn Univ., AL (United States). Dept. of Materials Engineering; Grossbeck, M.L. [Oak Ridge National Lab., TN (United States)

    1992-12-31T23:59:59.000Z

    Experiments have shown that Type 316 stainless steel is susceptible to heat-affected-zone (HAZ) cracking upon cooling when welded using the gas tungsten arc (GTA) process under lateral constraint. The cracking has been hypothesized to be caused by stress-assisted helium bubble growth and rupture at grain boundaries. This study utilized an experimental welding setup which enabled different compressive stresses to be applied to the plates during welding. Autogenous GTA welds were produced in Type 316 stainless steel doped with 256 appm helium. The application of a compressive stress, 55 Mpa, during welding suppressed the previously observed catastrophic cracking. Detailed examinations conducted after welding showed a dramatic change in helium bubble morphology. Grain boundary bubble growth along directions parallel to the weld was suppressed. Results suggest that stress-modified welding techniques may be used to suppress or eliminate helium-induced cracking during joining of irradiated materials.

  6. Repair welding of fusion reactor components. Second year technical report

    SciTech Connect (OSTI)

    Chin, B.A.

    1993-05-15T23:59:59.000Z

    Experiments have shown that irradiated Type 316 stainless steel is susceptible to heat-affected-zone (HAZ) cracking upon cooling when welded using the gas tungsten arc (GTA) process under lateral constraint. The cracking has been hypothesized to be caused by stress-assisted helium bubble growth and rupture at grain boundaries. This study utilized an experimental welding setup which enabled different compressive stresses to be applied to the plates during welding. Autogenous GTA welds were produced in Type 316 stainless steel doped with 256 appm helium. The application of a compressive stress, 55 MPa, during welding suppressed the previously observed catastrophic cracking. Detailed examinations conducted after welding showed a dramatic change in helium bubble morphology. Grain boundary bubble growth along directions parallel to the weld was suppressed. Results suggest that stress-modified welding techniques may be used to suppress or eliminate helium-induced cracking during joining of irradiated materials.

  7. WELDING RESEARCH -s231WELDING JOURNAL

    E-Print Network [OSTI]

    Zhang, YuMing

    WELDING RESEARCH -s231WELDING JOURNAL ABSTRACT. Double-electrode gas metal arc welding (DE the welding wire and the bypass torch. To control the base metal current at the desired level, a group. Introduction Gas metal arc welding (GMAW) is a major process for metals joining. Conventional GMAW is normally

  8. Residual stresses in weld overlay tubes: A finite element study

    SciTech Connect (OSTI)

    Taljat, B.; Zacharia, T.; Wang, X.L.; Keiser, J.R. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.; Feng, Z. [Edison Welding Inst., Columbus, OH (United States); Jirinec, M.J. [Welding Services, Inc., Norcross, GA (United States)

    1997-01-03T23:59:59.000Z

    Residual stresses and strains in a tube with circumferential weld overlay were analyzed by the finite element (FE) method. The objective of this work was to develop and verify a FE model, to determine the magnitude and distribution of residual stresses in the weld overlay tube, and to evaluate the significance of two contributing factors to residual stress: (1) difference in material properties between tube and weld material, and (2) thermal gradients in the weld. An axisymmetric FE model was developed to simulate the circumferential two-layer welding process of alloy 625 overlay on SA210 tube. The first layer was modeled as a gas metal arc welding process with filler metal, whereas the autogenous gas tungsten arc welding process was modeled for the second layer. Neutron diffraction technique was used to experimentally determine residual elastic strains in the weld overlay tube. Comparison with the FE results shows overall good agreement. Both the experimental and FE results show high compressive stresses at the inside tube surface and high tensile stresses in the weld overlay. This suggests that weld overlay may be used to relieve tensile or produce compressive stresses at the inside tube surface, which is significant for applications where crack initiation is found at the root pass of the joining weld.

  9. Hybrid laser welding techniques for enhanced welding efficiency

    SciTech Connect (OSTI)

    Beyer, E.; Poprawe, R. [Fraunhofer-Institut fuer Lasertechnik (ILT), Aachen (Germany); Brenner, B. [Fraunhofer-Institut fuer Werkstoffphysik und Schichttechnologie (IWS), Dresden (Germany)

    1996-12-31T23:59:59.000Z

    One of the remarkable characteristics of the laser beam welding process is its thin deep welding seam. This thin seam is produced as a result of the high welding speed and the low heat input, leading to a low distortion. However, the overall electrical efficiency of a CO{sub 2}-laser is in the range of 5-7% and the efficiency of a Nd:YAG-laser is only approximately 2-3%. There are several applications in which the thin laser seam and the high welding speed, in particular, have technical advantages, making the whole process economical. However, there are also a lot of possible applications, for which laser welding is too expensive at the moment or, in which the thin seam leads to a lot of unsolved metallurgical problems. To avoid these problems, a welding technique is presently being developed at the ILT and IWS which combines laser keyhole welding with Tungsten inert gas and metal inert gas welding and introduces an inductor for a preheating and a controlled heat flow. The paper is divided into two sections. The first section describes recent investigations carried out by the ILT into the laser arc combination and the second section describes the combination of the laser and induction techniques, presenting also an application presently being used in production in the car industry. This work has been completed by the Fraunhofer-Institut fur Werkstoffphysik und Schichttechnologie IWS in Dresden.

  10. The modelling of irradiation-enhanced phosphorus segregation in neutron irradiated reactor pressure vessel submerged-arc welds

    SciTech Connect (OSTI)

    Druce, S.G.; English, C.A.; Foreman, A.J.E.; McElroy, R.J.; Vatter, I.A. [AEA Technology, Didcot (United Kingdom). Harwell Lab.; Bolton, C.J.; Buswell, J.T.; Jones, R.B. [Nuclear Electric, Berkeley (United Kingdom). Berkeley Technology Centre

    1996-12-31T23:59:59.000Z

    Recent results on neutron-irradiated RPV submerged-arc welds have revealed grain boundary segregation of phosphorus during irradiation, which may lead to intergranular fracture. However, the experimental database is insufficient to define the dependence of the process on variables such ad dose, dose-rate and temperature. This paper describes work in which two existing models of phosphorus segregation, under thermal or irradiation conditions, have been developed to obtain predictions of these dependencies. The critical parameters in the models have been adjusted to give consistency with the available reference data, and predictions have been made of the dependence of segregation on a number of variables.

  11. Electron beam weld development on a Filter Pack Assembly. Final report

    SciTech Connect (OSTI)

    Dereskiewicz, J.P.

    1994-06-01T23:59:59.000Z

    A continuous electron beam welding procedure was developed to replace the manual gas tungsten arc welding procedure on the Filter Pack Assembly. A statistical study was used to evaluate the feasibility of electron beam welding 6061-T6 aluminum covers to A356 cast weldments throughout the joint tolerance range specified on product drawings. Peak temperature exposures were not high enough to degrade the heat sensitive electrical components inside the cast weldment. Actual weldments with alodine coating on the weld joint area were successfully cleaned using a nonmetallic fiberglass brush cleaning method.

  12. The effective spectral irradiance of ultra-violet radiations from inert-gas-shielded welding processes in relation to the ARC current density 

    E-Print Network [OSTI]

    DeVore, Robin Kent

    1973-01-01T23:59:59.000Z

    fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1973 Major Subject: Industrial Hygiene THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED WELDING PROCESSES IN RELATION TO THE ARC CURRENT... DENSITY A Thesis by ROBIN KENT DEVORE Approved as to style and content by: C alarm n of o itte Hea o partment e er Member December 1973 ABSTRACT The Effective Spectral Irradiance of Ultraviolet Radiations from Inert-Gas-Shielded Welding...

  13. Survey of welding processes for field fabrication of 2 1/4 Cr-1 Mo steel pressure vessels. [128 references

    SciTech Connect (OSTI)

    Grotke, G.E.

    1980-04-01T23:59:59.000Z

    Any evaluation of fabrication methods for massive pressure vessels must consider several welding processes with potential for heavy-section applications. These include submerged-arc and shielded metal-arc, narrow-joint modifications of inert-gas metal-arc and inert-gas tungsten-arc processes, electroslag, and electron beam. The advantage and disadvantages of each are discussed. Electroslag welding can be dropped from consideration for joining of 2 1/4 Cr-1 Mo steel because welds made with this method do not provide the required mechanical properties in the welded and stress relieved condition. The extension of electron-beam welding to sections as thick as 4 or 8 inches (100 or 200 mm) is too recent a development to permit full evaluation. The manual shielded metal-arc and submerged-arc welding processes have both been employed, often together, for field fabrication of large vessels. They have the historical advantage of successful application but present other disadvantages that make them otherwise less attractive. The manual shielded metal-arc process can be used for all-position welding. It is however, a slow and expensive technique for joining heavy sections, requires large amounts of skilled labor that is in critically short supply, and introduces a high incidence of weld repairs. Automatic submerged-arc welding has been employed in many critical applications and for welding in the flat position is free of most of the criticism that can be leveled at the shielded metal-arc process. Specialized techniques have been developed for horizontal and vertical position welding but, used in this manner, the applications are limited and the cost advantage of the process is lost.

  14. The effective spectral irradiance of ultra-violet radiations from inert-gas-shielded welding processes in relation to the ARC current density

    E-Print Network [OSTI]

    DeVore, Robin Kent

    1973-01-01T23:59:59.000Z

    THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED MELDING PROCESSES IN RELATION TO THE ARC CURRENT DENSITY A Thesis by ROBIN KENT DEVORE Submitted to the Graduate College of Texas A&M University in partial... fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1973 Major Subject: Industrial Hygiene THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED WELDING PROCESSES IN RELATION TO THE ARC CURRENT...

  15. Weld solidification cracking in 304 to 204L stainless steel

    SciTech Connect (OSTI)

    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

    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.

  16. Weld solidification cracking in 304 to 304L stainless steel

    SciTech Connect (OSTI)

    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

    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.

  17. Direct Observations of the (Alpha to Gamma) Transformation at Different Input Powers in the Heat Affected Zone of 1045 C-Mn Steel Arc Welds Observed by Spatially Resolved X-Ray Diffraction

    SciTech Connect (OSTI)

    Palmer, T A; Elmer, J W

    2005-03-16T23:59:59.000Z

    Spatially Resolved X-Ray Diffraction (SRXRD) experiments have been performed during Gas Tungsten Arc (GTA) welding of AISI 1045 C-Mn steel at input powers ranging from 1000 W to 3750 W. In situ diffraction patterns taken at discreet locations across the width of the heat affected zone (HAZ) near the peak of the heating cycle in each weld show regions containing austenite ({gamma}), ferrite and austenite ({alpha}+{gamma}), and ferrite ({alpha}). Changes in input power have a demonstrated effect on the resulting sizes of these regions. The largest effect is on the {gamma} phase region, which nearly triples in width with increasing input power, while the width of the surrounding two phase {alpha}+{gamma} region remains relatively constant. An analysis of the diffraction patterns obtained across this range of locations allows the formation of austenite from the base metal microstructure to be monitored. After the completion of the {alpha} {yields} {gamma} transformation, a splitting of the austenite peaks is observed at temperatures between approximately 860 C and 1290 C. This splitting in the austenite peaks results from the dissolution of cementite laths originally present in the base metal pearlite, which remain after the completion of the {alpha} {yields} {gamma} transformation, and represents the formation of a second more highly alloyed austenite constituent. With increasing temperatures, carbon, originally present in the cementite laths, diffuses from the second newly formed austenite constituent to the original austenite constituent. Eventually, a homogeneous austenitic microstructure is produced at temperatures of approximately 1300 C and above, depending on the weld input power.

  18. Electron microscopy and small angle neutron scattering study of precipitation in low alloy steel submerged-arc welds

    SciTech Connect (OSTI)

    Williams, T.J. [Rolls-Royce and Associates Ltd., Raynesway (United Kingdom); Phythian, W.J. [AEA Reactors Services, Didcot (United Kingdom)

    1996-12-31T23:59:59.000Z

    In previous studies, submerged-arc welds with a range of compositions were irradiated in test reactors over a range of dose and dose-rates. The effect of irradiation was measured by Charpy V-notch and hardness tests, and an irradiation response model was developed. In this paper the authors report the results of a combined electron microscopy and small angle neutron scattering (SANS) study on material from some of the Charpy specimens. The results have been interpreted in terms of the Russell and Brown modulus hardening model. In general they have confirmed the predictions of the irradiation response model, and shown that the copper precipitation contribution to the observed macroscopic to the observed macroscopic hardening is strongly dependent on nickel, dose and dose-rate.

  19. Influence of nitrogen in the shielding gas on corrosion resistance of duplex stainless steel welds

    SciTech Connect (OSTI)

    Bhatt, R.B.; Kamat, H.S.; Ghosal, S.K.; De, P.K.

    1999-10-01T23:59:59.000Z

    The influence of nitrogen in shielding gas on the corrosion resistance of welds of a duplex stainless steel (grade U-50), obtained by gas tungsten arc (GTA) with filler wire, autogenous GTA (bead-on-plate), electron beam welding (EBW), and microplasma techniques, has been evaluated in chloride solutions at 30 C. Pitting attack has been observed in GTA, electron beam welding, and microplasma welds when welding has been carried out using pure argon as the shielding gas. Gas tungsten arc welding with 5 to 10% nitrogen and 90 to 95% argon, as the shielding gas, has been found to result in an improved pitting corrosion resistance of the weldments of this steel. However, the resistance of pitting of autogenous welds (bead-on-plate) obtained in pure argon as the shielding gas has been observed to remain unaffected. Microscopic examination, electron probe microanalysis (EPMA), and x-ray diffraction studies have revealed that the presence of nitrogen in the shielding gas in the GTA welds not only modifies the microstructure and the austenite to ferrite ratio but also results in a nearly uniform distribution of the various alloying elements, for example, chromium, nickel, and molybdenum among the constituent phases, which are responsible for improved resistance to pitting corrosion.

  20. CLOSURE WELD DEVELOPMENT FOR 3013 OUTER CONTAINERS

    SciTech Connect (OSTI)

    Daugherty, W.; Howard, S.; Peterson, K.; Stokes, M.

    2009-11-10T23:59:59.000Z

    Excess plutonium materials in the DOE complex are packaged and stored in accordance with DOE-STD-3013. This standard specifies requirements for the stabilization of such materials and subsequent packaging in dual nested seal-welded containers. Austenitic stainless steels have been selected for container fabrication. The inner 3013 container provides contamination control while the outer 3013 container is the primary containment vessel and is the focus of this paper. Each packaging site chose a process for seal welding the outer 3013 containers in accordance with its needs and expertise. The two processes chosen for weld closure were laser beam welding (LBW) and gas tungsten arc welding (GTAW). Following development efforts, each system was qualified in accordance with DOE-STD-3013 prior to production use. The 3013 outer container closure weld joint was designed to accommodate the characteristics of a laser weld. This aspect of the joint design necessitated some innovative process and equipment considerations in the application of the GTAW process. Details of the weld requirements and the development processes are presented and several potential enhancements for the GTAW system are described.

  1. Development of models for welding applications

    SciTech Connect (OSTI)

    Roper, J.R.; Hayer, L.K.

    1990-01-01T23:59:59.000Z

    The modeling of welding processes offers considerable potential for help with manufacturing problems but a complete definition of any welding process offers many challenges. However, the modular structure of MARC, and the diverse range of capabilities offered, create a good opportunity for development in this area. This paper discusses these problems and describes techniques used to overcome some of them. Models have been developed to simulate gas tungsten arc (GTA) and electron beam (EB) welding with a moving heat source. Fortran routines for subroutines FLUX and FORCDT have been written to generate a moving heat source. Sequential element activation has permitted the simulation of GTA welding with cold wire feed (CWF), as in filling of a machined weld groove. A program which generates History Definition blocks necessary for this type of welding model is also described in this paper. Semi-infinite heat transfer elements were used to get accurate temperature histories while keeping the size of the model manageable. Time-temperature histories and isothermal contours compare well with experimental measurements, although many areas for improvement and refinement remain. Results have been used to anticipate the necessity for weld parameter changes after part redesign, and the electron beam model relates closely to situations in which information is needed for the minimization of peak temperatures on the underside of the welded part. 8 refs., 11 figs.

  2. WELDING RESEARCH -S249WELDING JOURNAL

    E-Print Network [OSTI]

    Zhang, YuMing

    WELDING RESEARCH -S249WELDING JOURNAL ABSTRACT. Double-sided arcing uses two torches on the opposite sides of the workpiece to force the welding current to flow through the thickness. If a keyhole is established through the thickness, part of the welding current will flow through the keyhole and maintain

  3. Welding aluminum alloys 6061 with the opposing dual-torch GTAW process

    SciTech Connect (OSTI)

    Zhang, Y.M.; Zhang, S.B. [Univ. of Kentucky, Lexington, KY (United States)

    1999-06-01T23:59:59.000Z

    Cracking is a major concern in welding aluminum alloys. Although weld solidification cracks can be eliminated through the addition of filler metal, the additives modify the alloy or base metal constituents and may not always be desirable. High-energy beam processes, such as electron beam welding, that result in minimal heat input reduce crack sensitivity, but their high cost limits their applications. In this study, the conventional gas tungsten arc welding process is modified by disconnecting the workpiece form the power supply and placing a second torch on the opposite side of the workpiece. Such a modification changes the direction of the current flow, improves the weld penetration and reduces the heat input. Using this modified process, 6061-T651 alloy was welded without filler metals. Analysis suggested the reduced heat input, the changed direction of the current flow and the symmetric heating were responsible for the observed reduction of the cracking sensitivity.

  4. Mechanical Properties of Aluminum Tailor Welded Blanks at Superplastic Temperatures

    SciTech Connect (OSTI)

    Davies, Richard W.; Vetrano, John S.; Smith, Mark T.; Pitman, Stan G.

    2002-10-06T23:59:59.000Z

    This paper describes an investigation of the mechanical properties of weld material in aluminum tailor welded blanks (TWB) at superplastic temperatures and discusses the potential application of TWBs in superplastic forming operations. Aluminum TWBs consist of multiple sheet materials of different thickness or alloy that are butt-welded together into a single, variable thickness blank. To evaluate the performance of the weld material in TWBs, a series of tensile tests were conducted at superplastic temperatures with specimens that contained weld material in the gage area. The sheet material used in the study was Sky 5083 aluminum alloy, which was joined to produce the TWBs by gas tungsten arc welding using an AA5356 filler wire. The experimental results show that, in the temperature range of 500?C to 550?C and at strain rates ranging from 10-4 sec-1 to 10-2 sec-1, the weld material has a higher flow stress and lower ductility than the monolithic sheet material. The weld material exhibited elongations of 40% to 60% under these conditions, whereas the monolithic sheet achieved 220% to 360% elongation. At the same temperatures and strain rates, the weld material exhibited flow stresses 1.3 to 4 times greater than the flow stress in the monolithic sheet. However, the weld material did show a substantial increase in the strain rate sensitivity and ductility when compared to the same material formed at room temperature.

  5. Residual stress in laser welded dissimilar steel tube-to-tube joints

    SciTech Connect (OSTI)

    Sun, Zheng (Technical Research Centre of Finland, Espoo (Finland). Lab. of Production Engineering)

    1993-09-01T23:59:59.000Z

    Austenitic-ferritic dissimilar steel joints are widely used in power generation systems. Their utilization has proved to be efficient in terms of satisfactory properties and the economics. These types of joints have usually been produced using conventional welding processes, such as tungsten inert gas (TIG) welding. With the rapid development of high power lasers, laser welding has received considerable attention. Laser welding offers many advantages over conventional welding processes, e.g. low heat input, small heat-affected zone (HAZ), small distortion, and welding in an exact and reproducible manner. Residual stress distribution in laser welds may also differ from those made by conventional welding processes due to its special features. Residual stress, particularly tensile residual stress in the weld, can be very important factor in controlling the quality and service life of the welded structure. The formation of tensile residual stress in the weld may result in the initiation of fatigue cracking, stress corrosion cracking or other types of fractures. It is useful, therefore, to understand the distribution of residual stress in austenitic-ferritic laser welds, and thus evaluate the quality of the joints. Although residual stress distribution in the welded joints has been extensively investigated, little data are available for the residual stress distribution in laser welds. The aim of the work was to examine residual stress distribution along laser welds of dissimilar steel tube-to-tube joints, which were made by both autogeneous welding and welding with filler wire. The results were also compared with the joints made by plasma arc and TIG welding.

  6. Reduced Pressure Electron Beam Welding Evaluation Activities on a Ni-Cr-Mo Alloy for Nuclear Waste Packages

    SciTech Connect (OSTI)

    Wong, F; Punshon, C; Dorsch, T; Fielding, P; Richard, D; Yang, N; Hill, M; DeWald, A; Rebak, R; Day, S; Wong, L; Torres, S; McGregor, M; Hackel, L; Chen, H-L; Rankin, J

    2003-09-11T23:59:59.000Z

    The current waste package design for the proposed repository at Yucca Mountain Nevada, USA, employs gas tungsten arc welding (GTAW) in fabricating the waste packages. While GTAW is widely used in industry for many applications, it requires multiple weld passes. By comparison, single-pass welding methods inherently use lower heat input than multi-pass welding methods which results in lower levels of weld distortion and also narrower regions of residual stresses at the weld TWI Ltd. has developed a Reduced Pressure Electron Beam (RPEB) welding process which allows EB welding in a reduced pressure environment ({le} 1 mbar). As it is a single-pass welding technique, use of RPEB welding could (1) achieve a comparable or better materials performance and (2) lead to potential cost savings in the waste package manufacturing as compared to GTAW. Results will be presented on the initial evaluation of the RPEB welding on a Ni-Cr-Mo alloy (a candidate alloy for the Yucca Mountain waste packages) in the areas of (a) design and manufacturing simplifications, (b) material performance and (c) weld reliability.

  7. Irradiation effects on fracture toughness of two high-copper submerged-arc welds, HSSI Series 5. Volume 1, Main report and Appendices A, B, C, and D

    SciTech Connect (OSTI)

    Nanstad, R.K.; Haggag, F.M.; McCabe, D.E.; Iskander, S.K.; Bowman, K.O. [Oak Ridge National Lab., TN (United States); Menke, B.H. [Materials Engineering Associates, Inc., Lanham, MD (United States)

    1992-10-01T23:59:59.000Z

    The Fifth Irradiation Series in the Heavy-Section Steel Irradiation Program obtained a statistically significant fracture toughness data base on two high-copper (0.23 and 0.31 wt %) submerged-arc welds to determine the shift and shape of the K{sub Ic} curve as a consequence of irradiation. Compact specimens with thicknesses to 101.6 mm (4 in) in the irradiated condition and 203.2 mm (8 in) in the unirradiated condition were tested, in addition to Charpy impact, tensile, and drop-weight specimens. Irradiations were conducted at a nominal temperature of 288{degree}C and an average fluence of 1.5 {times} 10{sup 19} neutrons/cm{sup 2} (>l MeV). The Charpy 41-J temperature shifts are about the same as the corresponding drop-weight NDT temperature shifts. The irradiated welds exhibited substantial numbers of cleavage pop-ins. Mean curve fits using two-parameter (with fixed intercept) nonlinear and linearized exponential regression analysis revealed that the fracture toughness 100 MPa{lg_bullet}{radical}m shifts exceeded the Charpy 41-J shifts for both welds. Analyses of curve shape changes indicated decreases in the slopes of the fracture toughness curves, especially for the higher copper weld. Weibull analyses were performed to investigate development of lower bound curves to the data, including the use of a variable K{sub min} parameter which affects the curve shape.

  8. TUNGSTEN--2001 80.1 By Kim B. Shedd

    E-Print Network [OSTI]

    , electrical, heating, and welding applications. Tungsten is also used to make heavy-metal alloys for armaments- temperature lubricants. U.S. apparent consumption of all tungsten materials in 2001 remained approximately

  9. TUNGSTEN--2002 80.1 By Kim B. Shedd

    E-Print Network [OSTI]

    , electrical, heating, and welding applications. Tungsten is also used to make heavy-metal alloys for armaments, high-temperature lubricants, and semiconductors. U.S. apparent consumption of all tungsten materials

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

    SciTech Connect (OSTI)

    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

    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.

  11. EFFECT OF MINOR ADDITIONS OF HYDROGEN TO ARGON SHIELDING GAS WHEN WELDING AUSTENITIC STAINLESS STEEL WITH THE GTAW PROCESS

    SciTech Connect (OSTI)

    CANNELL, G.R.

    2004-12-15T23:59:59.000Z

    This paper provides the technical basis to conclude that the use of hydrogen containing shielding gases during welding of austenitic stainless steels will not lead to hydrogen induced cracking (HIC) of the weld or weld heat affected zone. Argon-hydrogen gas mixtures, with hydrogen additions up to 35% [1], have been successfully used as the shielding gas in gas tungsten arc welding (GTAW) of austenitic stainless steels. The addition of hydrogen improves weld pool wettability, bead shape control, surface cleanliness and heat input. The GTAW process is used extensively for welding various grades of stainless steel and is preferred when a very high weld quality is desired, such as that required for closure welding of nuclear materials packages. The use of argon-hydrogen gas mixtures for high-quality welding is occasionally questioned, primarily because of concern over the potential for HIC. This paper was written specifically to provide a technical basis for using an argon-hydrogen shielding gas in conjunction with the development, at the Savannah River Technology Center (SRTC), of an ''optimized'' closure welding process for the DOE standardized spent nuclear fuel canister [2]. However, the basis developed here can be applied to other applications in which the use of an argon-hydrogen shielding gas for GTAW welding of austenitic stainless steels is desired.

  12. Weld overlay cladding with iron aluminides

    SciTech Connect (OSTI)

    Goodwin, G.M.

    1996-11-01T23:59:59.000Z

    The hot and cold cracking tendencies of some early iron aluminide alloy compositions limited their use to applications where good weldability was not required. Considerable progress has been made toward improving this situation. Using hot crack testing techniques developed at ORNL and a systematic study of alloy compositional effects, we have established a range of compositions within which hot cracking resistance is very good, essentially equivalent to stainless steel. Cold cracking, however, remains an issue, and extensive efforts are continuing to optimize composition and welding parameters, especially preheat and postweld heat treatment, to minimize its occurrence. In terms of filler metal and process development, we have progressed from sheared strip through aspiration cast rod and shielded metal arc electrodes to the point where we can now produce composite wire with a steel sheath and aluminum core in coil form, which permits the use of both the gas tungsten arc and gas metal arc processes. This is a significant advancement in that the gas metal arc process lends itself well to automated welding, and is the process of choice for commercial weld overlay applications. Using the newly developed filler metals, we have prepared clad specimens for testing in a variety of environments both in-house and outside ORNL, including laboratory and commercial organizations. As a means of assessing the field performance of this new type of material, we have modified several non-pressure boundary boiler components, including fuel nozzles and port shrouds, by introducing areas of weld overlay in strategic locations, and have placed these components in service in operating boilers for a side-by-side comparison with conventional corrosion-resistant materials.

  13. Microstructure, hardness profile and tensile strength in welds of AA6013 T6 extrusions

    SciTech Connect (OSTI)

    Guitterez, L.A. [Colorado School of Mines, Golden, CO (United States). Center for Welding and Joining Research; Neye, G.; Zschech, E. [Daimler-Benz Aerospace Airbus GmbH, Bremen (Germany)

    1996-04-01T23:59:59.000Z

    Alloy AA6013 is easily welded by conventional arc welding processes as well as by high-energy-density processes. However, some physical properties, which are inherent to all aluminum alloys, have to be considered during welding. In comparison to steel, the high thermal conductivity of aluminum alloys requires the use of higher heat input for welding. This is realized by a greater welding current during GTAW of aluminum alloys. One of the main problems associated with LBW of aluminum alloys is the high surface reflectivity. In particular, the threshold intensity for the development of a keyhole is much higher for aluminum than for steel. Finally, aluminum alloys, and particularly the heat-treatable alloys, are sensitive to weld cracking. This phenomenon can be avoided by proper filler and base metal alloy selection and adequate filler metal dilution. In order to improve the mechanical integrity of Al-Mg-Si weldments, it would be desirable to study the microstructure of the FZ and of the HAZ, as well as the residual stress distribution. The present study was performed in order to show differences in microstructure, hardness profile and tensile strength of gas tungsten arc (GTA) and laser beam (LB) welded AA6013-T6 extrusions. In addition, grain boundary liquations and hot tearing are discussed.

  14. OREGON STATE UNIVERSITY (OSU) TRAINING RESEARCH ISOTOPE GENERAL ATOMICS (TRIGA) OVERPACK CLOSURE WELDING PROCESS PARAMETER DEVELOPMENT & QUALIFICATION

    SciTech Connect (OSTI)

    CANNELL, G.R.

    2006-09-11T23:59:59.000Z

    Spent Nuclear Fuel (SNF) from the Oregon State University (OSU) TRIGA{reg_sign} Reactor is currently being stored in thirteen 55-gallon drums at the Hanford Site's low-level burial grounds. This fuel is soon to be retrieved from buried storage and packaged into new containers (overpacks) for interim storage at the Hanford Interim Storage Area (ISA). One of the key activities associated with this effort is final closure of the overpack by welding. The OSU fuel is placed into an overpack, a head inserted into the overpack top, and welded closed. Weld quality, for typical welded fabrication, is established through post-weld testing and nondestructive examination (NDE); however, in this case, once the SNF is placed into the overpack, routine testing and NDE are not feasible. An alternate approach is to develop and qualify the welding process/parameters, demonstrate beforehand that they produce the desired weld quality, and then verify parameter compliance during production welding. Fluor engineers have developed a Gas Tungsten Arc Welding (GTAW) technique and parameters, demonstrating that weld quality requirements for closure of packaged SNF overpacks are met, using this alternate approach. The following reviews the activities performed for this development and qualification effort.

  15. In: O'Brien R L (ed.) Welding Handbook-Volume 3: Materials and Applications, 8th Edn. American Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    (fastening, adhesive bonding, soldering, brazing, arc welding, diffusion bonding, resistance welding, etc, such as diffusion bonding, come very close to this ideal; .·. ·.'· .. . . . : ' : \\. ·:-';..·. .: ... Joining

  16. Fusion Welding of AerMet 100 Alloy

    SciTech Connect (OSTI)

    ENGLEHART, DAVID A.; MICHAEL, JOSEPH R.; NOVOTNY, PAUL M.; ROBINO, CHARLES V.

    1999-08-01T23:59:59.000Z

    A database of mechanical properties for weldment fusion and heat-affected zones was established for AerMet{reg_sign}100 alloy, and a study of the welding metallurgy of the alloy was conducted. The properties database was developed for a matrix of weld processes (electron beam and gas-tungsten arc) welding parameters (heat inputs) and post-weld heat treatment (PWHT) conditions. In order to insure commercial utility and acceptance, the matrix was commensurate with commercial welding technology and practice. Second, the mechanical properties were correlated with fundamental understanding of microstructure and microstructural evolution in this alloy. Finally, assessments of optimal weld process/PWHT combinations for cotildent application of the alloy in probable service conditions were made. The database of weldment mechanical properties demonstrated that a wide range of properties can be obtained in welds in this alloy. In addition, it was demonstrated that acceptable welds, some with near base metal properties, could be produced from several different initial heat treatments. This capability provides a means for defining process parameters and PWHT's to achieve appropriate properties for different applications, and provides useful flexibility in design and manufacturing. The database also indicated that an important region in welds is the softened region which develops in the heat-affected zone (HAZ) and analysis within the welding metallurgy studies indicated that the development of this region is governed by a complex interaction of precipitate overaging and austenite formation. Models and experimental data were therefore developed to describe overaging and austenite formation during thermal cycling. These models and experimental data can be applied to essentially any thermal cycle, and provide a basis for predicting the evolution of microstructure and properties during thermal processing.

  17. Plasma arc torch with coaxial wire feed

    DOE Patents [OSTI]

    Hooper, Frederick M (Albuquerque, NM)

    2002-01-01T23:59:59.000Z

    A plasma arc welding apparatus having a coaxial wire feed. The apparatus includes a plasma arc welding torch, a wire guide disposed coaxially inside of the plasma arc welding torch, and a hollow non-consumable electrode. The coaxial wire guide feeds non-electrified filler wire through the tip of the hollow non-consumable electrode during plasma arc welding. Non-electrified filler wires as small as 0.010 inches can be used. This invention allows precision control of the positioning and feeding of the filler wire during plasma arc welding. Since the non-electrified filler wire is fed coaxially through the center of the plasma arc torch's electrode and nozzle, the wire is automatically aimed at the optimum point in the weld zone. Therefore, there is no need for additional equipment to position and feed the filler wire from the side before or during welding.

  18. Experimental investigation of welding penetration-depth in high-purity aluminium

    SciTech Connect (OSTI)

    Tong, W. [Babcock and Wilcox, Lynchburg, VA (United States). Naval Nuclear Fuel Div.

    1996-12-31T23:59:59.000Z

    One of the most important parameters in the superconducting splice design is the welding penetration-depth because it determines the electrical resistivity across the welded joints through the high-purity aluminum stabilizers. Highly resistive welds could lead to conductor instability when the superconductor goes normal. In the present investigation, experiments were performed using gas tungsten-arc welding to identify the effects of the welding parameters on the penetration-depth. The experimental results will be applied to the optimization of the superconducting splice design. The mock-up test data and theoretical analysis have shown that the higher energy input and lower welding speed produce the deeper penetration-depth in high-purity aluminum. In order to achieve an approximately uniform penetration-depth, three methods were explored: (i) a starting-delay at the welding start point, (ii) an external cooling, and (iii) staggered overlapping weldments. The experimental results have suggested that a uniform penetration-depth can be obtained under the thermal equilibrium welding conditions.

  19. Qualification of large diameter duplex stainless steel girth welds intended for low temperature service

    SciTech Connect (OSTI)

    Prosser, K.; Robinson, A.G.; Rogers, P.F.

    1996-12-31T23:59:59.000Z

    British Gas recently had a requirement to fabricate some UNS31803 duplex stainless steel pipework for an offshore topsides process plant. The pipework had a maximum diameter of 600mm, with a corresponding wall thickness of 18mm, and it was designed to operate at a minimum temperature of {minus}40 C. There is a lack of published toughness data for girth welds in duplex stainless steel at this thickness and minimum design temperature. Additionally, toughness requirements for girth welds in current pipework and pressure vessel codes are based on experience with carbon steels. As a result, a program of work has been carried out to study the Charpy, CTOD and wide plate toughness of girth welds in 22%Cr duplex stainless steel pipework. The welds were produced using a typical gas tungsten arc/gas metal arc pipework fabrication procedure. In addition, non-destructive evaluation trials have been carried out on a deliberately defective weld using radiography and ultrasonics. It was demonstrated that double wall single image {gamma}-radiography, single wall single image and panoramic X-radiography, and conventional shear wave ultrasonics were all able to detect planar root defects varying from 3 to 7mm in depth. There was good agreement between the sizes recorded by ultrasonics and those measured from macrosections. Small scale mechanical tests demonstrated that welds with overmatching tensile properties, and low temperature toughness properties which were acceptable to specification, could be produced. Wide plate tests demonstrated that defect size calculations from BS PD7493 were conservative.

  20. Characterization of microstructure, chemical composition, corrosion resistance and toughness of a multipass weld joint of superduplex stainless steel UNS S32750

    SciTech Connect (OSTI)

    Tavares, S.S.M. [Universidade Federal Fluminense, Departamento de Engenharia Mecanica/PGMEC, Rua Passo da Patria, 156, CEP 24210-240, Niteroi/RJ (Brazil)]. E-mail: ssmtavares@terra.com.br; Pardal, J.M. [Universidade Federal Fluminense, Departamento de Engenharia Mecanica/PGMEC, Rua Passo da Patria, 156, CEP 24210-240, Niteroi/RJ (Brazil); Lima, L.D. [Universidade Federal Fluminense, Departamento de Engenharia Mecanica/PGMEC, Rua Passo da Patria, 156, CEP 24210-240, Niteroi/RJ (Brazil); Bastos, I.N. [Universidade do Estado do Rio de Janeiro (UERJ), Instituto Politecnico (IPRJ), Nova Friburgo/RJ (Brazil); Nascimento, A.M. [Universidade Estadual de Campinas (UNICAMP), Departamento de Engenharia Mecanica, Campinas/SP (Brazil); Souza, J.A. de [Universidade Federal Fluminense, Departamento de Engenharia Mecanica/PGMEC, Rua Passo da Patria, 156, CEP 24210-240, Niteroi/RJ (Brazil)

    2007-07-15T23:59:59.000Z

    The superduplex stainless steels have an austeno-ferritic microstructure with an average fraction of each phase of approximately 50%. This duplex microstructure improves simultaneously the mechanical properties and corrosion resistance. Welding of these steels is often a critical operation. In this paper we focus on characterization and analysis of a multipass weld joint of UNS S32750 steel prepared using welding conditions equal to industrial standards. The toughness and corrosion resistance properties of the base metal, root pass welded with gas tungsten arc welding, as well as the filler passes, welded with shielded metal arc welding, were evaluated. The microstructure and chemical composition of the selected areas were also determined and correlated to the corrosion and mechanical properties. The root pass was welded with low nickel filler metal and, as a consequence, presented low austenite content and significant precipitation. This precipitation is reflected in the corrosion and mechanical properties. The filler passes presented an adequate ferrite:austenite proportion but, due to their high oxygen content, the toughness was lower than that of the root pass. Corrosion properties were evaluated by cyclic polarization tests in 3.5% NaCl and H{sub 2}SO{sub 4} media.

  1. Modeling Arcs

    SciTech Connect (OSTI)

    Insepov, Z.; Norem, J. [Argonne National Lab, Argonne, IL 60439 (United States); Vetizer, S.; Mahalingam, S. [Tech-X Corp., Boulder, CO (United States)

    2011-12-23T23:59:59.000Z

    Although vacuum arcs were first identified over 110 years ago, they are not yet well understood. We have since developed a model of breakdown and gradient limits that tries to explain, in a self-consistent way: arc triggering, plasma initiation, plasma evolution, surface damage and gradient limits. We use simple PIC codes for modeling plasmas, molecular dynamics for modeling surface breakdown, and surface damage, and mesoscale surface thermodynamics and finite element electrostatic codes for to evaluate surface properties. Since any given experiment seems to have more variables than data points, we have tried to consider a wide variety of arcing (rf structures, e beam welding, laser ablation, etc.) to help constrain the problem, and concentrate on common mechanisms. While the mechanisms can be comparatively simple, modeling can be challenging.

  2. Method for welding beryllium

    DOE Patents [OSTI]

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

    1997-01-01T23:59:59.000Z

    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.

  3. WELDING RESEARCH FEBRUARY 2008, VOL. 87-s44

    E-Print Network [OSTI]

    Zhang, YuMing

    WELDING RESEARCH FEBRUARY 2008, VOL. 87-s44 ABSTRACT. Consumable double- electrode gas metal arc welding (DE- GMAW) is an innovative welding process that can significantly increase the deposi- tion rate arc welding(GMAW)gunandconstantcurrent (CC) power supply to a conventional GMAW setup -- Fig. 1

  4. A comparison of LBW and GTAW processes in miniature closure welds

    SciTech Connect (OSTI)

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

    1995-07-01T23:59:59.000Z

    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.

  5. Development of weld closure stations for plutonium long-term storage containers

    SciTech Connect (OSTI)

    Fernandez, R.; Martinez, D.A.; Martinez, H.E.; Nelson, T.O.; Ortega, R.E.; Rofer, C.K.; Romero, W.; Stewart, J.; Trujillo, V.L.

    1998-12-31T23:59:59.000Z

    Weld closure stations for plutonium long-term storage containers have been designed, fabricated, and tested for the Advanced Recovery and Integrated Extraction System (ARIES) at the TA-55 Plutonium Facility of the Los Alamos National Laboratory. ARIES is a processing system used for the dismantlement of the plutonium pits from nuclear weapons. ARIES prepares the extracted-plutonium in a form which is compatible with long-term storage and disposition options and meets international inspection requirements. The processed plutonium is delivered to the canning module of the ARIES line, where it is packaged in a stainless steel container. This container is then packaged in a secondary container for long-term storage. Each of the containers is hermetically sealed with a full penetration weld closure that meets the requirements of the ASME Section IX Boiler and Pressure Vessel Code. Welding is performed with a gas tungsten arc process in an inert atmosphere of helium. The encapsulated helium in the nested containers allows for leak testing the weld closure and container. The storage package was designed to meet packaging requirements of DOE Standard 3013-96 for long-term storage of plutonium metal and oxides. Development of the process parameters, weld fixture, weld qualification, and the welding chambers is discussed in this paper.

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

    SciTech Connect (OSTI)

    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

    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.

  7. Characterization of Low Temperature Ferrite/Austenite Transformations in the Heat Affected Zone of 2205 Duplex Stainless Steel Arc Welds

    SciTech Connect (OSTI)

    Palmer, T A; Elmer, J W; Babu, S S; Vitek, J M

    2003-08-20T23:59:59.000Z

    Spatially Resolved X-Ray Diffraction (SRXRD) has been used to identify a previously unobserved low temperature ferrite ({delta})/austenite({gamma}) phase transformation in the heat affected zone (HAZ) of 2205 Duplex Stainless Steel (DSS) welds. In this ''ferrite dip'' transformation, the ferrite transforms to austenite during heating to peak temperatures on the order of 750 C, and re-transforms to ferrite during cooling, resulting in a ferrite volume fraction equivalent to that in the base metal. Time Resolved X-Ray Diffraction (TRXRD) and laser dilatometry measurements during Gleeble{reg_sign} thermal simulations are performed in order to verify the existence of this low temperature phase transformation. Thermodynamic and kinetic models for phase transformations, including both local-equilibrium and para-equilibrium diffusion controlled growth, show that diffusion of substitutional alloying elements does not provide a reasonable explanation for the experimental observations. On the other hand, the diffusion of interstitial alloying elements may be rapid enough to explain this behavior. Based on both the experimental and modeling results, two mechanisms for the ''ferrite dip'' transformation, including the formation and decomposition of secondary austenite and an athermal martensitic-type transformation of ferrite to austenite, are considered.

  8. Chapter 7 -Welding The dangers in welding, cutting, heating and grinding should never be underestimated.

    E-Print Network [OSTI]

    36 Chapter 7 - Welding The dangers in welding, cutting, heating and grinding should never and to understand the hazards involved. Spot the hazard Hazards associated with welding include: · The arc itself eyes can become extremely red and sore and in extreme cases suffer permanent damage. · Welding gases

  9. Analysis of weld solidification cracking in cast nickel aluminide alloys

    SciTech Connect (OSTI)

    Santella, M.L.; Feng, Z. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1995-09-01T23:59:59.000Z

    A study of the response of several nickel aluminide alloys to SigmaJig testing was done to examine their weld solidification cracking behavior and the effect of Zr concentration. The alloys were based on the Ni-8Al-7.7Cr-1.5Mo-0.003B wt% composition and contained Zr concentrations of 3, 4.5, and 6 wt%. Vacuum induction melted ingots with a diameter of 2.7 in and weight about 18 lb were made of each alloy, and were used to make 2 x 2 x 0.030 in specimens for the Sigmajig test. The gas tungsten arc welds were made at travel speeds of 10, 20, and 30 ipm with heat inputs of 2--2.5 kJ/in. When an arc was established before traveling onto the test specimen centerline cracking was always observed. This problem was overcome by initiating the arc directly on the specimens. Using this approach, the 3 wt% Zr alloy withstood an applied stress of 24 ksi without cracking at a welding speed of 10 ipm. This alloy cracked at 4 ksi applied at 20 ipm, and with no applied load at 30 ipm. Only limited testing was done on the remaining alloys, but the results indicate that resistance to solidification cracking increases with Zr concentration. Zirconium has limited solid solubility and segregates strongly to interdendritic regions during solidification where it forms a Ni solid solution-Ni{sub 5}Zr eutectic. The volume fraction of the eutectic increases with Zr concentration. The solidification cracking behavior of these alloys is consistent with phenomenological theory, and is discussed in this context. The results from SigmaJig testing are analyzed using finite element modeling of the development of mechanical strains during solidification of welds. Experimental data from the test substantially agree with recent analysis results.

  10. Fracture toughness of Ti-6Al-4V after welding and postweld heat treatment

    SciTech Connect (OSTI)

    Murthy, K.K.; Sundaresan, S. [Indian Inst. of Tech., Madras (India). Dept. of Metallurgical Engineering

    1997-02-01T23:59:59.000Z

    The fracture toughness (J{sub IC}) of the fusion zone of Ti-6Al-4V alloy welds was studied in terms of microstructural changes in the as-welded condition and following postweld heat treatment. Gas tungsten arc and electron beam welds were produced in sheet material over a limited range of heat input and subsequently heat treated at 700 C and 900 C. In the as-welded condition, the weld microstructure was a mixture of diffusional and martensitic alpha phases, whose proportion varied wit heat input and cooling rate. The fusion zone exhibited low ductility resulting from the highly acicular microstructure and a large prior-beta grain size. Postweld heat treatment tempered the martensite and coarsened the microstructure, but a beneficial effect on ductility was realized only after treatment at 900 C. Fracture toughness in the as-welded condition was greater than for the base metal and was attributed to the lamellar microstructure of the fusion zone and absence of continuous alpha film along the grain boundaries. Postweld heat treatment at 700 C reduced the fracture toughness considerably and, as in the case of ductility, it was necessary to heat treat at 900 C to produce an improvement.

  11. Fusion welding of advanced borated stainless steels. Final report: CRADA No. CR1042

    SciTech Connect (OSTI)

    Robino, C.V.; Cieslak, M.J.

    1994-02-01T23:59:59.000Z

    This work addressed two major areas concerning joining of advanced borated stainless steels. These areas included the development of a understanding of the physical metallurgy of borated stainless steels and the development of welding processes and post-weld heat treatments for these alloys. Differential thermal analysis experiments were conducted on ten heats of borated stainless steel to determine the transformation temperatures and melting behavior of the alloys. On-heating solidus temperatures were measured for all of the alloys and were used to define the temperatures associated with the fusion line during welding. Isothermal heat treatments designed to evaluate the effects of elevated temperature exposures on the toughness of the borated grades were conducted. These tests were used to determine if significant changes in the microstructure or mechanical properties of weld heat-affected zones (HAZ) occur. Specifically, the tests addressed the solid-state region of the HAZ. The test matrix included a variety of alloy compositions and thermal exposures at temperatures near the on-heating solidus (as determined by the DTA experiments). Welding experiments designed to assess the mechanical properties and microstructure of gas-tungsten arc and electron beam welds were conducted.

  12. TUNGSTEN--1999 80.1 By Kim B. Shedd

    E-Print Network [OSTI]

    , and/or contacts are used in lighting, electronic, electrical, heating, and welding applications and coatings. Chemical uses of tungsten include catalysts, inorganic pigments, and high-temperature lubricants

  13. TUNGSTEN--1998 80.1 By Kim B. Shedd

    E-Print Network [OSTI]

    , and/or contacts are used in lighting, electronic, electrical, heating, and welding applications and coatings. Chemical uses of tungsten include catalysts, inorganic pigments, and high-temperature lubricants

  14. A Level Set Approach for the Simulation of the Multipass Hybrid Laser / GMA Welding Process

    E-Print Network [OSTI]

    1 A Level Set Approach for the Simulation of the Multipass Hybrid Laser / GMA Welding Process model, developed in a level set approach, is proposed to model hybrid gas metal arc / laser welding equation, the momentum and mass conservation equations and the weld bead development. The arc welding total

  15. Corrosion Resistant Cladding by YAG Laser Welding in Underwater Environment

    SciTech Connect (OSTI)

    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

    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)

  16. Welding tritium aged stainless steel

    SciTech Connect (OSTI)

    Kanne, W.R. Jr.

    1993-04-01T23:59:59.000Z

    Stainless steels exposed to tritium become unweldable by conventional methods due to He buildup within the metal matrix. With longer service lives expected for new weapon systems, and service life extensions of older systems, methods for welding/repair on tritium-exposed material will become important. Results are reported that indicate that both solid-state resistance welding and low-heat gas metal arc overlay welding are promising methods for repair or modification of tritium-aged stainless steel.

  17. Weld Surfacing Edited by Dr I.A. Bucklow

    E-Print Network [OSTI]

    Cambridge, University of

    becomesconfigurationally frozen at a temperature of about 1150°Cduring deposition by the manual-metal-arc welding techniqueV01.II Weld Surfacing Edited by Dr I.A. Bucklow ConferenceTechnicalDirector Organised by The Welding Institute in associationwith The Surface Engineering Society THE WELDING INSTITUTE #12;L

  18. Method for welding beryllium

    DOE Patents [OSTI]

    Dixon, R.D.; Smith, F.M.; O`Leary, R.F.

    1997-04-01T23:59:59.000Z

    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. 9 figs.

  19. Laser welding and post weld treatment of modified 9Cr-1MoVNb steel.

    SciTech Connect (OSTI)

    Xu, Z. (Nuclear Engineering Division)

    2012-04-03T23:59:59.000Z

    Laser welding and post weld laser treatment of modified 9Cr-1MoVNb steels (Grade P91) were performed in this preliminary study to investigate the feasibility of using laser welding process as a potential alternative to arc welding methods for solving the Type IV cracking problem in P91 steel welds. The mechanical and metallurgical testing of the pulsed Nd:YAG laser-welded samples shows the following conclusions: (1) both bead-on-plate and circumferential butt welds made by a pulsed Nd:YAG laser show good welds that are free of microcracks and porosity. The narrow heat affected zone has a homogeneous grain structure without conventional soft hardness zone where the Type IV cracking occurs in conventional arc welds. (2) The laser weld tests also show that the same laser welder has the potential to be used as a multi-function tool for weld surface remelting, glazing or post weld tempering to reduce the weld surface defects and to increase the cracking resistance and toughness of the welds. (3) The Vicker hardness of laser welds in the weld and heat affected zone was 420-500 HV with peak hardness in the HAZ compared to 240 HV of base metal. Post weld laser treatment was able to slightly reduce the peak hardness and smooth the hardness profile, but failed to bring the hardness down to below 300 HV due to insufficient time at temperature and too fast cooling rate after the time. Though optimal hardness of weld made by laser is to be determined for best weld strength, methods to achieve the post weld laser treatment temperature, time at the temperature and slow cooling rate need to be developed. (4) Mechanical testing of the laser weld and post weld laser treated samples need to be performed to evaluate the effects of laser post treatments such as surface remelting, glazing, re-hardening, or tempering on the strength of the welds.

  20. May 19-21, 2010 Marrakech, Morocco.

    E-Print Network [OSTI]

    Boyer, Edmond

    Gas' process (TIG), also called Gas Tungsten Arc Welding (GTAW) is a welding process using a tungsten : Morocco (2010)" #12;2 2 Hot tearing phenomenon in welding 2.1 TIG arc welding process The 'Tungsten Inert , a crack created during arc welding on a 6056 aluminum alloy is clearly visible. The purpose

  1. Irradiation effects on fracture toughness of two high-copper submerged-arc welds, HSSI series 5. Volume 2, Appendices E and F

    SciTech Connect (OSTI)

    Nanstad, R.K.; Haggag, F.M.; McCabe, D.E.; Iskander, S.K.; Bowman, K.O. [Oak Ridge National Lab., TN (United States); Menke, B.H. [Materials Engineering Associates, Inc., Lanham, MD (United States)

    1992-10-01T23:59:59.000Z

    The Fifth Irradiation Series in the Heavy-Section Steel irradiation (HSSI) Program was aimed at obtaining a statistically significant fracture toughness data base on two weldments with high-copper contents to determine the shift and shape of the K{sub lc} curve as a consequence of irradiation. The program included irradiated Charpy V-notch impact, tensile, and drop-weight specimens in addition to compact fracture toughness specimens. Compact specimens with thicknesses of 25.4, 50.8, and 101.6 mm [1T C(T), 2T C(T), and 4T C(T), respectively] were irradiated. Additionally, unirradiated 6T C(T) and 8T C(T) specimens with the same K{sub lc} measuring capacity as the irradiated specimens were tested. The materials for this irradiation series were two weldments fabricated from special heats of weld wire with copper added to the melt. One lot of Linde 0124 flux was used for all the welds. Copper levels for the two welds are 0.23 and 0.31 wt %, while the nickel contents for both welds are 0.60 wt %. Twelve capsules of specimens were irradiated in the pool-side facility of the Oak Ridge Research Reactor at a nominal temperature of 288{degree}C and an average fluence of about 1.5 {times} 10{sup 19} neutrons/cm{sup 2} (> 1 MeV). This volume, Appendices E and F, contains the load-displacement curves and photographs of the fracture toughness specimens from the 72W weld (0.23 wt % Cu) and the 73 W weld (0.31 wt % Cu), respectively.

  2. Overlay welding irradiated stainless steel

    SciTech Connect (OSTI)

    Kanne, W.R.; Chandler, G.T.; Nelson, D.Z.; Franco-Ferreira, E.A.

    1993-08-01T23:59:59.000Z

    An overlay technique developed for welding irradiated stainless steel may be important for repair or modification of fusion reactor materials. Helium, present due to n,{alpha} reactions, is known to cause cracking using conventional welding methods. Stainless steel impregnated with 3 to 220 appm helium by decay of tritium was used to develop a welding process that could be used for repair. The result was a gas metal arc weld overlay technique with low-heat input and low-penetration into the helium-containing material. Extensive metallurgical and mechanical testing of this technique demonstrated substantial reduction of helium embrittlement damage. The overlay technique was applied to irradiated 304 stainless steel containing 10 appm helium. Surface cracking, present in conventional welds made on the same steel at lower helium concentrations, was eliminated. Underbead cracking, although greater than for tritium charged and aged material, was minimal compared to conventional welding methods.

  3. Dr. Thomas A. Siewert IN-SPACE WELDING

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) ) Dr. Thomas A. Siewert IN-SPACE WELDING Visions & Realities presented to Thirtieth Space This paperestablishes the value of having an in-space welding capability and identifies its applications, both near, Plasma Arc, and Laser Beam, are examined against the criteria for an in-space welding system. Research

  4. High-pressure arcs as vacuum-atmosphere interface and plasma lens for nonvacuum electron beam welding machines, electron beam melting, and nonvacuum ion material modification

    SciTech Connect (OSTI)

    Hershcovitch, A. [AGS Department, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)] [AGS Department, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)

    1995-11-01T23:59:59.000Z

    Atmospheric pressure plasmas can be used to provide a vacuum-atmosphere interface as an alternative to differential pumping. Vacuum-atmosphere interface utilizing a cascade arc discharge was successfully demonstrated and a 175 keV electron beam was successfully propagated from vacuum through such a plasma interface and out into atmospheric pressure. Included in the article are a theoretical framework, experimental results, and possible applications for this novel interface. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  5. ~ WELDING RESEARCH ~Jlj~~~-------------!ID~ SUPPLEMENT TO THE tVELOING JOURNAL. IULY 1993

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ~ WELDING RESEARCH ~Jlj~~~-------------!ID~ SUPPLEMENT TO THE t·VELOING JOURNAL. IULY 1993 Sponsored by the American Welding Society and the Welding Research Council Metal Transfer in Pulsed Current Gas Metal Arc Welding A static force balance analysis was used to estimate the melting rates

  6. RESONANT TRANSITION SWITCHING WELDING POWER SUPPLY N. Frohleke, H. Mundinger, S. Beineke, P. Wallmeier, H. Grotstollen

    E-Print Network [OSTI]

    Paderborn, Universität

    RESONANT TRANSITION SWITCHING WELDING POWER SUPPLY N. Frohleke, H. Mundinger, S. Beineke, P-bridge topology used in a welding power supply. A new driving scheme adapts the resulting power circuitry for both the droplet and the short-circuiting transfer welding modes occurring in the gas metal arc welding process

  7. Finite Element Modeling and Validation of Residual Stresses in 304 L Girth Welds

    SciTech Connect (OSTI)

    Dike, J.J.; Ortega, A.R.; Cadden, C.H.; Rangaswamy, P. Brown, D.

    1998-06-01T23:59:59.000Z

    Three dimensional finite element simulations of thermal and mechanical response of a 304 L stainless steel pipe subjected to a circumferential autogenous gas tungsten arc weld were used to predict residual stresses in the pipe. Energy is input into the thermal model using a volumetric heat source. Temperature histories from the thermal analysis are used as loads in the mechanical analyses. In the mechanical analyses, a state variable constitutive model was used to describe the material behavior. The model accounts for strain rate, temperature, and load path histories. The predicted stresses are compared with x-ray diffraction determinations of residual stress in the hoop and circumferential directions on the outside surface of the pipe. Calculated stress profiles fell within the measured data. Reasons for observed scatter in measured stresses are discussed.

  8. G.M. Wright, VLT Highlight, March 28, 2012 Growth of tungsten nano-tendrils in

    E-Print Network [OSTI]

    1 G.M. Wright, VLT Highlight, March 28, 2012 Growth of tungsten nano-tendrils in the Alcator C morphology of a tungsten divertor modify into fuzz under Helium bombardment in ITER and reactors?! · Linear fragile nano-tendrils! · Increased unipolar arcing! · Likely higher net erosion and W dust production

  9. Towards Real Time Diagnostics of Hybrid Welding Laser/GMAW

    SciTech Connect (OSTI)

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

    2013-07-01T23:59:59.000Z

    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.

  10. Towards real time diagnostics of Hybrid Welding Laser/GMAW

    SciTech Connect (OSTI)

    McJunkin, T. R.; Kunerth, D. C.; Nichol, C. I. [Idaho National Laboratory, Idaho Falls, ID 83415-3570 (United States); Todorov, E.; Levesque, S. [Edison Welding Institute, Columbus, OH (United States)

    2014-02-18T23:59:59.000Z

    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.

  11. Modelling of friction stir welding

    E-Print Network [OSTI]

    Colegrove, Paul Andrew

    is influenced by the fractUling of the tungsten wire. Finally, Nowak et al. 85 examined the flow during the FSW of polycarbonate and found similar flow fields to those observed in aluminium. Because of polycarbonate's different properties it was necessary... is conducted into the tool and welded material, and is then convected from the top surface or conducted into the backing plate. Both analytical and numerical models have been used to describe this heat flow. The following section describes thermal modelling...

  12. Upgraded HFIR Fuel Element Welding System

    SciTech Connect (OSTI)

    Sease, John D [ORNL

    2010-02-01T23:59:59.000Z

    The welding of aluminum-clad fuel plates into aluminum alloy 6061 side plate tubing is a unique design feature of the High Flux Isotope Reactor (HFIR) fuel assemblies as 101 full-penetration circumferential gas metal arc welds (GMAW) are required in the fabrication of each assembly. In a HFIR fuel assembly, 540 aluminum-clad fuel plates are assembled into two nested annular fuel elements 610 mm (24-inches) long. The welding process for the HFIR fuel elements was developed in the early 1960 s and about 450 HFIR fuel assemblies have been successfully welded using the GMAW process qualified in the 1960 s. In recent years because of the degradation of the electronic and mechanical components in the old HFIR welding system, reportable defects in plate attachment or adapter welds have been present in almost all completed fuel assemblies. In October 2008, a contract was awarded to AMET, Inc., of Rexburg, Idaho, to replace the old welding equipment with standard commercially available welding components to the maximum extent possible while maintaining the qualified HFIR welding process. The upgraded HFIR welding system represents a major improvement in the welding system used in welding HFIR fuel elements for the previous 40 years. In this upgrade, the new inner GMAW torch is a significant advancement over the original inner GMAW torch previously used. The innovative breakthrough in the new inner welding torch design is the way the direction of the cast in the 0.762 mm (0.030-inch) diameter aluminum weld wire is changed so that the weld wire emerging from the contact tip is straight in the plane perpendicular to the welding direction without creating any significant drag resistance in the feeding of the weld wire.

  13. Dissimilar-alloy laser welding of titanium: Ti6Al-4V to Beta-C{trademark}

    SciTech Connect (OSTI)

    Liu, P.S.; Baeslack, W.A. III; Hurley, J.

    1994-12-31T23:59:59.000Z

    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.

  14. DESIGN OF THE HANFORD MULTI CANISTER OVERPACK (MCO) & DEVELOPMENT & QUALIFICATION OF THE CLOSURE WELDING PROCESS

    SciTech Connect (OSTI)

    CANNELL, G. R.

    2004-04-30T23:59:59.000Z

    Processing more than 2,100 metric tons of metallic uranium spent nuclear fuel (SNF) into large stainless steel containers called Multi-Canister Overpacks (MCOs) is one of the top priorities for the Department of Energy (DOE) at the Hanford Site, located in southeastern Washington state. The MCOs will be temporarily stored on site and eventually shipped to the federal geologic repository for long-term storage. MCOs are constructed and ''N''stamped in accordance with the requirements of the American Society of Mechanical Engineers (ASME) Section III, Division 1, Class 1 Components. Final closure welding poses a challenge after the fuel is loaded. Performing required examination and testing activities (volumetric examination and hydrostatic leak testing) can be difficult, if not impractical. An ASME Code Case N-595-3, was written specifically to allow code stamping by addressing such closures and providing alternative rules. MCOs are the first SNF canisters within the DOE complex to successfully use this code case for receiving ASME stamps. This paper discusses the design of the MCO, application of the N-595-3 code case, and development and qualification of the final welded closure. The MCO design considers internal pressure and handling loads, as well as processing and interim storage activities. The MCO functions as the primary or innermost containment as part of an overall transportation package so the design also considered interface features with secondary and transport containers. The MCO, approximately 2 feet in diameter and nearly 14 feet tall, is constructed primarily of Type 304/304L stainless steel and the final pressure boundary is of all-welded construction. The closure-weld is made with the Gas Tungsten Arc Welding (GTAW) process, using an automatic, machine-welding mode. Examination and testing of the closure includes the N-595-3 specified requirements-progressive Liquid Penetrant testing (PT) and final helium leak testing. At completion of the closure, the MCO is ''N'' stamped as a 450 pounds per square inch (design pressure) vessel. To ensure the process consistently achieves the required weld penetration, a series of developmental tests was performed to identify an optimum and robust set of welding parameters. Testing included test welds made on plate mockups and then actual MCO mockups. With the primary welding parameters (welding current and travel speed) established, a simple two-factor, two-level, factorial experiment with replication at high and low heat input conditions was conducted. Evaluation of the results included weld photomicrographs, which helped establish process range limits for these parameters broad enough to cover typical equipment and measurement variations and provide additional operating margin. To date, over 316 MCOs have been loaded, dried, and transported to the Canister Storage Building (CSB), where the welding is done. Of those, 161 MCOs have received final welded closure and ''N'' stamps. All cover cap final closure welds have met specified requirements without incident.

  15. Fatique Resistant, Energy Efficient Welding Program, Final Technical Report

    SciTech Connect (OSTI)

    Egland, Keith; Ludewig, Howard

    2006-05-25T23:59:59.000Z

    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.

  16. Oxygen and Nitroaen Contamination During Submerged Arc Wel ding of Titanium

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) ) ) ··- -~ Oxygen and Nitroaen Contamination During Submerged Arc Wel ding of Titanium T· \\v the costs of submerged arc welding of titanium. In general it i s found that the cost of titanium submerged welding of titani um. The advantages and disadvantages of flux shielded weldinq of titanium are outlined

  17. 202-s | JUNE 1999 RESEARCH/DEVELOPMENT/RESEARCH/DEVELOPMENT/RESEARCH/DEVELOPMENT/RESEARCH/DEVELOPMENT

    E-Print Network [OSTI]

    Zhang, YuMing

    . In this study, the conventional gas tungsten arc welding process is modified by disconnecting the workpiece from the arcs and improves the weld penetration, thus re- sulting in a reduction in the heat input. This process on productivity, cost and weld quality. In this study, the dual-torch gas tungsten arc welding (GTAW) process

  18. HAZ hardenability in welded C-Mn steels: The role of prior microstructure

    SciTech Connect (OSTI)

    Sarafinchin, D.; Patchett, B.M.

    1994-12-31T23:59:59.000Z

    The hardenability of the heat-affected zone (HAZ) in C-Mn steels is one of the primary influences on susceptibility to HAC in welded structures. Procedure control of HAZ hardness is based on the use of preheat and/or heat input to limit the peak HAZ hardness to 350--450 Hv10, depending on hydrogen level. Determination of procedural conditions depends on material thickness and carbon equivalent, but does not involve prior microstructure. This study investigated the influence of hot-rolled and normalized base metal microstructures on the level, development and location of peak hardness in steels of identical chemical composition. One heat of A516Gr70 steel in the hot-rolled condition was cut in two and one-half was normalized. This produced microstructures of differing grain size and pearlite coarseness. Gas tungsten arc welding (GTAW) fusion welds at two heat inputs (0.5 and 2.5 KJ/mm) were placed in each of the two base metals. Macro-and microhardness surveys and metallographic analysis were used o determine the location and level of HAZ hardness. Carbon gradients due to incomplete dissolution of cementite and lack of time for homogenization by diffusion cause significant differences in macro-and microhardness of HAZ constituents in A516Gr70 weld zones. Increased pearlite grain size, and to a lesser extent, pearlite lamellar thickness, produce martensitic zones of high hardness in hot-rolled A516Gr70 in two regions: at temperatures just over the A{sub 3} and at temperatures just over the A{sub 1}. Of the two, the region just over the A{sub 3} although removed from the fusion line, has the highest HAZ hardness and is most likely to be susceptible to HAC. Normalized steel is likely to be more resistant to HAC in the HAZ than hot-rolled steel of identical chemical composition.

  19. Driven Motion and Instability of an Atmospheric Pressure Arc

    SciTech Connect (OSTI)

    Max Karasik

    1999-12-01T23:59:59.000Z

    Atmospheric pressure arcs are used extensively in applications such as welding and metallurgy. However, comparatively little is known of the physics of such arcs in external magnetic fields and the mechanisms of the instabilities present. In order to address questions of equilibrium and stability of such arcs, an experimental arc furnace is constructed and operated in air with graphite cathode and steel anode at currents 100-250 A. The arc is diagnosed with a gated intensified camera and a collimated photodiode array, as well as fast voltage and current probes.

  20. Slag Metal Reactions in Binary CaF2-Metal Oxide Welding Fluxes

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) Slag Metal Reactions in Binary CaF2-Metal Oxide Welding Fluxes Some otherwise chemically stable fluxes may decompose into suboxides in the presence of welding arcs, thereby providing higher levels of 0 2 in weld metal than those oxides which do not form suboxides ABSTRACT. The stability of metal

  1. Modeling solute redistribution and microstructural development in fusion welds of multi-component alloys

    SciTech Connect (OSTI)

    Dupont, J.N.; Robino, C.V.; Newbury, B.D.

    1999-12-15T23:59:59.000Z

    Solute redistribution and microstructural evolution have been modeled for gas tungsten arc fusion welds in experimental Ni base superalloys. The multi-component alloys were modeled as a pseudo-ternary {gamma}-Nb-C system. The variation in fraction liquid and liquid composition during the primary L {r{underscore}arrow} {gamma} and eutectic type L {r{underscore}arrow} ({gamma} + NbC) stages of solidification were calculated for conditions of negligible Nb diffusion and infinitely rapid C diffusion in the solid phase. Input parameters were estimated by using the Thermo-Calc NiFe Alloy data base and compared to experimentally determined solidification parameters. The solidification model results provide useful information for qualitatively interpreting the influence of alloy composition on weld microstructure. The quantitative comparisons indicate that, for the alloy system evaluated, the thermodynamic database provides sufficiently accurate values for the distribution coefficients of Nb and C. The calculated position of the {gamma}-NbC two-fold saturation line produces inaccurate results when used as inputs for the model, indicating further refinement to the database is needed for quantitative estimates.

  2. WELDING RESEARCH -s85WELDING JOURNAL

    E-Print Network [OSTI]

    Zhang, YuMing

    WELDING RESEARCH -s85WELDING JOURNAL ABSTRACT. Measurement of weld pool surface is a difficult but urgent task in the welding community. It plays an important role not only in developing the next- generation intelligent welding machines but also for modeling complex welding processes. In recent years

  3. arc welding welding: Topics by E-print Network

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

    phased arrays is inspection speed: linear travel speeds of up to 100 mmsec are possible. Sizing is typically performed using diffraction approaches (TOFD and back diffraction),...

  4. Welding and Weldability of Thorium-Doped Iridium Alloys

    SciTech Connect (OSTI)

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

    2000-03-12T23:59:59.000Z

    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.

  5. WELDING RESEARCH -s57WELDING JOURNAL

    E-Print Network [OSTI]

    Zhang, YuMing

    WELDING RESEARCH -s57WELDING JOURNAL ABSTRACT. Low heat input is typically desired for welding high welding. However, a high current, and thus a high heat input, is required to melt more wire to achieve the HAZ size, microstructure, and the hard- ness of high-strength steel ASTM A514 welded by DE

  6. WELDING RESEARCH -S237WELDING JOURNAL

    E-Print Network [OSTI]

    Cambridge, University of

    WELDING RESEARCH -S237WELDING JOURNAL We depend in our everyday life on the performance of vast the tallest building in the world -- Fig. 1. These are all made from steel and rely on welding for their assembly. Weld Design: Experiment or Model? A weld is a heterogeneity introduced into a carefully

  7. WELDING RESEARCH -s87WELDING JOURNAL

    E-Print Network [OSTI]

    Eagar, Thomas W.

    WELDING RESEARCH -s87WELDING JOURNAL ABSTRACT. Welding fume contains ele- ments that, in their pure of welding fume must be examined when considering fume toxicity. Various chemical analysis techniques are pre techniques to analyze the chemistry of mild steel welding fume. X-ray diffraction (XRD) shows that mild steel

  8. Heat flow during the autogenous GTA welding of pipes

    SciTech Connect (OSTI)

    Kou, S.; Le, Y.

    1984-06-01T23:59:59.000Z

    A theoretical and experimental study of heat flow during the welding of pipes was carried out. The theoretical part of the study involves the development of two finite difference computer models: one for describing steady state, 3-dimensional heat flow during seam welding, the other for describing unsteady state, 3-dimensional heat flow during girth welding. The experimental part of the study, on the other hand, includes: measurement of the thermal response of the pipe with a high speed data acquisition system, determination of the arc efficiency with a calorimeter, and examination of the fusion boundary of the resultant weld. The experimental results were compared with the calculated ones, and the agreement was excellent in the case of seam welding and reasonably good in the case of girth welding. Both the computer models and experiments confirmed that, under a constant heat input and welding speed, the size of the fusion zone remains unchanged in seam welding but continues to increase in girth welding of pipes of small diameters. It is expected that the unsteady state model developed can be used to provide optimum conditions for girth welding, so that uniform weld beads can be obtained and weld defects such as lack of fusion and sagging can be avoided.

  9. DIGITAL SIGNAL PROCESSING AS A DIAGNOSTIC TOOL FOR GAS

    E-Print Network [OSTI]

    Eagar, Thomas W.

    DIGITAL SIGNAL PROCESSING AS A DIAGNOSTIC TOOL FOR GAS TUNGSTEN ARC WELDING Carl D. Sorensen by the intense heat and light of the ·elding arc. To avoid these problems it is desirable to use the welding arc. The arc is treated as an electrical "black box" with the weld current as an input and the weld voltage

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

    SciTech Connect (OSTI)

    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

    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.

  11. Increasing Productivity of Welding

    E-Print Network [OSTI]

    Uhrig, J. J.

    1983-01-01T23:59:59.000Z

    It is universally recognized that welding is the most economical way to permanently join metals. Recent advances in welding, specifically, the continuous electrode wire processes make welding even more attractive for manufacturing. As welding...

  12. Increasing Productivity of Welding 

    E-Print Network [OSTI]

    Uhrig, J. J.

    1983-01-01T23:59:59.000Z

    It is universally recognized that welding is the most economical way to permanently join metals. Recent advances in welding, specifically, the continuous electrode wire processes make welding even more attractive for manufacturing. As welding...

  13. WELDING RESEARCH ~----------------------~--~ SUPPLEMENT TO THE WELDING JOURNAL. FEBRUARY 1990

    E-Print Network [OSTI]

    Eagar, Thomas W.

    J ) WELDING RESEARCH ~----------------------~--~ SUPPLEMENT TO THE WELDING JOURNAL. FEBRUARY 1990 Sponsored by the American Welding Society and the Welding Research Council All papers published in the Welding Journal's Welding Research Supplement undergo Peer Review before publication for: I) originality

  14. Microstructure of Titanium Welds

    SciTech Connect (OSTI)

    Danielson, Paul; Wilson, Rick D.; Alman, David E.

    2003-02-01T23:59:59.000Z

    Plates of commercially pure titanium were welded and microscopically analyzed to understand the influence of joining variables on weld microstructure.

  15. Wonder Weld

    SciTech Connect (OSTI)

    None

    2012-01-01T23:59:59.000Z

    Engineers at the U.S. Department of Energy's Princeton Plasma Physics Laboratory are using the process shown here to create a super-strong weld for the upgrade of a key component of the Lab's experimental nuclear fusion reactor.

  16. Tungsten Cathode Catalyst for PEMFC

    SciTech Connect (OSTI)

    Joel B. Christian; Sean P. E. Smith

    2006-09-22T23:59:59.000Z

    Final report for project to evaluate tungsten-based catalyst as a cathode catalyst for PEM cell applications.

  17. Aluminum-tungsten fiber composites with cylindrical geometry and controlled architecture of tungsten reinforcement

    E-Print Network [OSTI]

    Lucchese, Carl Joesph

    2010-01-01T23:59:59.000Z

    Measurements in Alumina and Tungsten Fibre-Reinforcedto-Ductile Transition in Tungsten Single Crystals. ” ScienceToughness of Polycrystalline Tungsten Under Mode I and Mixed

  18. WELDING RESEARCH -s77WELDING JOURNAL

    E-Print Network [OSTI]

    DuPont, John N.

    WELDING RESEARCH -s77WELDING JOURNAL ABSTRACT. The microstructure of AL- 6XN plates joined via a double-sided fric- tion stir weld has been investigated. The microstructural zones that develop during friction stir welding (FSW) reflect de- creasing strains and less severe thermal cy- cles with increasing

  19. WELDING RESEARCH -s51WELDING JOURNAL

    E-Print Network [OSTI]

    DuPont, John N.

    WELDING RESEARCH -s51WELDING JOURNAL ABSTRACT. Electron microprobe analy- sis was utilized to examine the gradient of alloying elements across the weld inter- face of austenitic/ferritic dissimilar alloy welds. The concentration gradients were converted to martensite start (Ms) tem- perature gradients

  20. WELDING RESEARCH -s281WELDING JOURNAL

    E-Print Network [OSTI]

    DuPont, John N.

    WELDING RESEARCH -s281WELDING JOURNAL ABSTRACT. Superaustenitic stainless steel alloys can often pose difficulties dur- ing fusion welding due to the unavoidable microsegregation of Mo and tramp ele. A method of producing austenitic welds is proposed that can po- tentially circumvent these issues by de

  1. WELDING RESEARCH -S125WELDING JOURNAL

    E-Print Network [OSTI]

    DuPont, John N.

    WELDING RESEARCH -S125WELDING JOURNAL ABSTRACT. Microstructural evolution and solidification cracking susceptibility of dissimilar metal welds between AL- 6XN super austenitic stainless steel and two, differential thermal analysis, and Varestraint testing tech- niques. Welds were prepared over the en- tire

  2. SOAR: An extensible suite of codes for weld analysis and optimal weld schedules

    SciTech Connect (OSTI)

    Eisler, G.R.; Fuerschbach, P.W.

    1997-07-01T23:59:59.000Z

    A suite of MATLAB-based code modules has been developed to provide optimal weld schedules, regulating weld process parameters for CO2 and pulse Nd:YAG laser welding methods, and arc welding in support of the Smartweld manufacturing initiative at Sandia National Laboratories. The optimization methodology consists of mixed genetic and gradient-based algorithms to query semi-empirical, nonlinear algebraic models. The optimization output provides heat-input-efficient welds for user-specified weld dimensions. User querying of all weld models is available to examine sub-optimal schedules. In addition, a heat conduction equation solver for 2-D heat flow is available to provide the user with an additional check of weld thermal effects. The inclusion of thermodynamic properties allows the extension of the empirical models to include materials other than those tested. All solution methods are provided with graphical user interfaces and display pertinent results in two and three-dimensional form. The code architecture provides an extensible framework to add an arbitrary number of modules.

  3. Narrow gap laser welding

    DOE Patents [OSTI]

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

    1998-01-01T23:59:59.000Z

    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.

  4. Narrow gap laser welding

    DOE Patents [OSTI]

    Milewski, J.O.; Sklar, E.

    1998-06-02T23:59:59.000Z

    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.

  5. Helium bubble bursting in tungsten

    SciTech Connect (OSTI)

    Sefta, Faiza [University of California, Berkeley, California 94720 (United States); Juslin, Niklas [University of Tennessee, Knoxville, Tennessee 37996 (United States); Wirth, Brian D., E-mail: bdwirth@utk.edu [University of Tennessee, Oak Ridge National Laboratory, Knoxville, Tennessee 37996 (United States)

    2013-12-28T23:59:59.000Z

    Molecular dynamics simulations have been used to systematically study the pressure evolution and bursting behavior of sub-surface helium bubbles and the resulting tungsten surface morphology. This study specifically investigates how bubble shape and size, temperature, tungsten surface orientation, and ligament thickness above the bubble influence bubble stability and surface evolution. The tungsten surface is roughened by a combination of adatom “islands,” craters, and pinholes. The present study provides insight into the mechanisms and conditions leading to various tungsten topology changes, which we believe are the initial stages of surface evolution leading to the formation of nanoscale fuzz.

  6. Preparation, Characterization, and Catalytic Properties of Tungsten...

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

    Preparation, Characterization, and Catalytic Properties of Tungsten Trioxide Cyclic Trimers on FeO(111)Pt(111). Preparation, Characterization, and Catalytic Properties of Tungsten...

  7. Comproportionation of Cationic and Anionic Tungsten Complexes...

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

    Comproportionation of Cationic and Anionic Tungsten Complexes Having an N-Heterocyclic Carbene Ligand to Give the Isolable 17 Comproportionation of Cationic and Anionic Tungsten...

  8. PDC IC WELD FAILURE EVALUATION AND RESOLUTION

    SciTech Connect (OSTI)

    Korinko, P.; Howard, S.; Maxwell, D.; Fiscus, J.

    2012-04-16T23:59:59.000Z

    During final preparations for start of the PDCF Inner Can (IC) qualification effort, welding was performed on an automated weld system known as the PICN. During the initial weld, using a pedigree canister and plug, a weld defect was observed. The defect resulted in a hole in the sidewall of the canister, and it was observed that the plug sidewall had not been consumed. This was a new type of failure not seen during development and production of legacy Bagless Transfer Cans (FB-Line/Hanford). Therefore, a team was assembled to determine the root cause and to determine if the process could be improved. After several brain storming sessions (MS and T, R and D Engineering, PDC Project), an evaluation matrix was established to direct this effort. The matrix identified numerous activities that could be taken and then prioritized those activities. This effort was limited by both time and resources (the number of canisters and plugs available for testing was limited). A discovery process was initiated to evaluate the Vendor's IC fabrication process relative to legacy processes. There were no significant findings, however, some information regarding forging/anneal processes could not be obtained. Evaluations were conducted to compare mechanical properties of the PDC canisters relative to the legacy canisters. Some differences were identified, but mechanical properties were determined to be consistent with legacy materials. A number of process changes were also evaluated. A heat treatment procedure was established that could reduce the magnetic characteristics to levels similar to the legacy materials. An in-situ arc annealing process was developed that resulted in improved weld characteristics for test articles. Also several tack welds configurations were addressed, it was found that increasing the number of tack welds (and changing the sequence) resulted in decreased can to plug gaps and a more stable weld for test articles. Incorporating all of the process improvements for the actual can welding process, however, did not result in an improved weld geometry. Several possibilities for the lack of positive response exist, some of which are that (1) an insufficient number of test articles were welded under prototypic conditions, (2) the process was not optimized so that significant improvements were observable over the 'noise', and (3) the in-situ arc anneal closed the gap down too much so the can was unable to exhaust pressure ahead of the weld. Several operational and mechanical improvements were identified. The weld clamps were changed to a design consistent with those used in the legacy operations. A helium puff operation was eliminated; it is believed that this operation was the cause of the original weld defect. Also, timing of plug mast movement was found to correspond with weld irregularities. The timing of the movement was changed to occur during weld head travel between tacks. In the end a three sequential tack weld process followed by a pulse weld at the same current and travel speed as was used for the legacy processes was suggested for use during the IC qualification effort. Relative to legacy welds, the PDC IC weld demonstrates greater fluctuation in the region of the weld located between tack welds. However, canister weld response (canister to canister) is consistent and with the aid of the optical mapping system (for targeting the cut position) is considered adequate. DR measurements and METs show the PDC IC welds to have sufficient ligament length to ensure adequate canister pressure/impact capacity and to ensure adequate stub function. The PDC welding process has not been optimized as a result of this effort. Differences remain between the legacy BTC welds and the PDC IC weld, but these differences are not sufficient to prevent resumption of the current PDC IC qualification effort. During the PDC IC qualification effort, a total of 17 cans will be welded and a variety of tests/inspections will be performed. The extensive data collected during that qualification effort should be of a sufficient population to determ

  9. Preparation of tungsten oxide

    DOE Patents [OSTI]

    Bulian, Christopher J. (Yankton, SD); Dye, Robert C. (Los Alamos, NM); Son, Steven F. (Los Alamos, NM); Jorgensen, Betty S. (Jemez Springs, NM); Perry, W. Lee (Jemez Springs, NM)

    2009-09-22T23:59:59.000Z

    Tungsten trioxide hydrate (WO.sub.3.H.sub.2O) was prepared from a precursor solution of ammonium paratungstate in concentrated aqueous hydrochloric acid. The precursor solution was rapidly added to water, resulting in the crash precipitation of a yellow white powder identified as WO.sub.3.H.sub.2O nanosized platelets by x-ray diffraction and scanning electron microscopy. Annealing of the powder at 200.degree. C. provided cubic phase WO.sub.3 nanopowder, and at 400.degree. C. provided WO.sub.3 nanopowder as a mixture of monoclinic and orthorhombic phases.

  10. High-bandwidth continuous-flow arc furnace

    DOE Patents [OSTI]

    Hardt, D.E.; Lee, S.G.

    1996-08-06T23:59:59.000Z

    A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics. 4 figs.

  11. High-bandwidth continuous-flow arc furnace

    DOE Patents [OSTI]

    Hardt, David E. (Concord, MA); Lee, Steven G. (Ann Arbor, MI)

    1996-01-01T23:59:59.000Z

    A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics.

  12. Combinatorial optimization of welding

    E-Print Network [OSTI]

    Sóbester, András

    C E D C Combinatorial optimization of welding sequences The problem Combinatorial optimization a welding example of a tail bearing housing vanes ­ Figure 1. The major structural details are the outer ring, the inner ring and the vanes. The vanes are welded to the rings using TIG welding. Fig. 1: Tail

  13. High strength uranium-tungsten alloys

    DOE Patents [OSTI]

    Dunn, Paul S. (Santa Fe, NM); Sheinberg, Haskell (Los Alamos, NM); Hogan, Billy M. (Los Alamos, NM); Lewis, Homer D. (Bayfield, CO); Dickinson, James M. (Los Alamos, NM)

    1991-01-01T23:59:59.000Z

    Alloys of uranium and tungsten and a method for making the alloys. The amount of tungsten present in the alloys is from about 4 wt % to about 35 wt %. Tungsten particles are dispersed throughout the uranium and a small amount of tungsten is dissolved in the uranium.

  14. High strength uranium-tungsten alloy process

    DOE Patents [OSTI]

    Dunn, Paul S. (Santa Fe, NM); Sheinberg, Haskell (Los Alamos, NM); Hogan, Billy M. (Los Alamos, NM); Lewis, Homer D. (Bayfield, CO); Dickinson, James M. (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    Alloys of uranium and tungsten and a method for making the alloys. The amount of tungsten present in the alloys is from about 4 wt % to about 35 wt %. Tungsten particles are dispersed throughout the uranium and a small amount of tungsten is dissolved in the uranium.

  15. WELDING RESEARCH SUPPLEMENT TO THE WELDING JOURNAL, JUNE, 1982

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) WELDING RESEARCH SUPPLEMENT TO THE WELDING JOURNAL, JUNE, 1982 Sponsored by the American Welding Society .1mJ the Welding Research Council The Effect of Electrical Resistance on Nugget Formation During Spot Welding Applying a higher resistance coating to HSLA steel increases the welding current range

  16. WELDING RESEARCH ~------------~-~ SUPPLEMENT TO THE WELDING JOURNAL, AUGUST 1989

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) ) WELDING RESEARCH ·~------------~-~ SUPPLEMENT TO THE WELDING JOURNAL, AUGUST 1989 Sponsored by the American Welding Society and the Welding Research Council All papers published in the Welding Journal's Welding Research Supplement undergo Peer Review before publication for: 1) originality of the contribution

  17. The Impact of Weld Metal Creep Strength on the Overall Creep Strength of 9% Cr Steel Weldments

    E-Print Network [OSTI]

    Mayr, Peter

    In this work, three joints of a X11CrMoWVNb9-1-1 (P911) pipe were welded with three filler metals by conventional arc welding. The filler metals varied in creep strength level, so that one overmatched, one undermatched, ...

  18. Discovery of the Tungsten Isotopes

    E-Print Network [OSTI]

    A. Fritsch; J. Q. Ginepro; M. Heim; A. Schuh; A. Shore; M. Thoennessen

    2009-03-25T23:59:59.000Z

    Thirty-five tungsten isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  19. Discovery of the tungsten isotopes

    SciTech Connect (OSTI)

    Fritsch, A.; Ginepro, J.Q.; Heim, M.; Schuh, A.; Shore, A. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Thoennessen, M. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)], E-mail: thoennessen@nscl.msu.edu

    2010-05-15T23:59:59.000Z

    Thirty-five tungsten isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  20. Discovery of the Tungsten Isotopes

    E-Print Network [OSTI]

    Fritsch, A; Heim, M; Schuh, A; Shore, A; Thoennessen, M

    2009-01-01T23:59:59.000Z

    Thirty-five tungsten isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  1. Fusion welding process

    DOE Patents [OSTI]

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

    1983-01-01T23:59:59.000Z

    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.

  2. Rotating arc spark plug

    DOE Patents [OSTI]

    Whealton, John H.; Tsai, Chin-Chi

    2003-05-27T23:59:59.000Z

    A spark plug device includes a structure for modification of an arc, the modification including arc rotation. The spark plug can be used in a combustion engine to reduce emissions and/or improve fuel economy. A method for operating a spark plug and a combustion engine having the spark plug device includes the step of modifying an arc, the modifying including rotating the arc.

  3. Process Of Bonding Copper And Tungsten

    DOE Patents [OSTI]

    Slattery, Kevin T. (St. Charles, MO); Driemeyer, Daniel E. (Manchester, MO); Davis, John W. (Ballwin, MO)

    2000-07-18T23:59:59.000Z

    Process for bonding a copper substrate to a tungsten substrate by providing a thin metallic adhesion promoting film bonded to a tungsten substrate and a functionally graded material (FGM) interlayer bonding the thin metallic adhesion promoting film to the copper substrate. The FGM interlayer is formed by sintering a stack of individual copper and tungsten powder blend layers having progressively higher copper content/tungsten content, by volume, ratio values in successive powder blend layers in a lineal direction extending from the tungsten substrate towards the copper substrate. The resulting copper to tungsten joint well accommodates the difference in the coefficient of thermal expansion of the materials.

  4. INSTITUTE OF PHYSICS PUBLISHING MEASUREMENT SCIENCE AND TECHNOLOGY Meas. Sci. Technol. 15 (2004) 991999 PII: S0957-0233(04)74770-0

    E-Print Network [OSTI]

    Zhang, YuMing

    2004-01-01T23:59:59.000Z

    for accurate control of heat input. As a close relative and modification of GTAW, plasma arc welding (PAW) has, penetration 1. Introduction Gas tungsten arc welding (GTAW) is the primary process for precision joining of metals due to its capability for accurate control of heat input. Although plasma arc welding (PAW

  5. Tungsten diffusion in silicon

    SciTech Connect (OSTI)

    De Luca, A.; Texier, M.; Burle, N.; Oison, V.; Pichaud, B. [Aix-Marseille Université, IM2NP UMR 7334, Faculté des Sciences et Techniques, Campus de Saint-Jérôme, Avenue Escadrille Normandie Niemen - Case 142, F-13397 Marseille Cedex (France); Portavoce, A., E-mail: alain.portavoce@im2np.fr [CNRS, IM2NP UMR 7334, Faculté des Sciences et Techniques, Campus de Saint-Jérôme, Avenue Escadrille Normandie Niemen - Case 142, F-13397 Marseille Cedex (France); Grosjean, C. [STMicroelectronics, Rousset (France)

    2014-01-07T23:59:59.000Z

    Two doses (10{sup 13} and 10{sup 15}?cm{sup ?2}) of tungsten (W) atoms were implanted in different Si(001) wafers in order to study W diffusion in Si. The samples were annealed or oxidized at temperatures between 776 and 960?°C. The diffusion profiles were measured by secondary ion mass spectrometry, and defect formation was studied by transmission electron microscopy and atom probe tomography. W is shown to reduce Si recrystallization after implantation and to exhibit, in the temperature range investigated, a solubility limit close to 0.15%–0.2%, which is higher than the solubility limit of usual metallic impurities in Si. W diffusion exhibits unusual linear diffusion profiles with a maximum concentration always located at the Si surface, slower kinetics than other metals in Si, and promotes vacancy accumulation close to the Si surface, with the formation of hollow cavities in the case of the higher W dose. In addition, Si self-interstitial injection during oxidation is shown to promote W-Si clustering. Taking into account these observations, a diffusion model based on the simultaneous diffusion of interstitial W atoms and W-Si atomic pairs is proposed since usual models used to model diffusion of metallic impurities and dopants in Si cannot reproduce experimental observations.

  6. Novel Optimization Methodology for Welding Process/Consumable Integration

    SciTech Connect (OSTI)

    Quintana, Marie A; DebRoy, Tarasankar; Vitek, John; Babu, Suresh

    2006-01-15T23:59:59.000Z

    Advanced materials are being developed to improve the energy efficiency of many industries of future including steel, mining, and chemical, as well as, US infrastructures including bridges, pipelines and buildings. Effective deployment of these materials is highly dependent upon the development of arc welding technology. Traditional welding technology development is slow and often involves expensive and time-consuming trial and error experimentation. The reason for this is the lack of useful predictive tools that enable welding technology development to keep pace with the deployment of new materials in various industrial sectors. Literature reviews showed two kinds of modeling activities. Academic and national laboratory efforts focus on developing integrated weld process models by employing the detailed scientific methodologies. However, these models are cumbersome and not easy to use. Therefore, these scientific models have limited application in real-world industrial conditions. On the other hand, industrial users have relied on simple predictive models based on analytical and empirical equations to drive their product development. The scopes of these simple models are limited. In this research, attempts were made to bridge this gap and provide the industry with a computational tool that combines the advantages of both approaches. This research resulted in the development of predictive tools which facilitate the development of optimized welding processes and consumables. The work demonstrated that it is possible to develop hybrid integrated models for relating the weld metal composition and process parameters to the performance of welds. In addition, these tools can be deployed for industrial users through user friendly graphical interface. In principle, the welding industry users can use these modular tools to guide their welding process parameter and consumable composition selection. It is hypothesized that by expanding these tools throughout welding industry, substantial energy savings can be made. Savings are expected to be even greater in the case of new steels, which will require extensive mapping over large experimental ranges of parameters such as voltage, current, speed, heat input and pre-heat.

  7. Spectroscopic characterization and imaging of laser- and unipolar arc-induced plasmas

    SciTech Connect (OSTI)

    Aussems, Damien U. B., E-mail: d.aussems@differ.nl [FOM Institute DIFFER—Dutch Institute for Fundamental Energy Research, Nieuwegein, NL-3430 BE (Netherlands); Nishijima, Daisuke; Brandt, Christian; Doerner, Russell P. [Center for Energy Research, University of California at San Diego, 9500 Gilman Drive, La Jolla, California 92093-0417 (United States); Cardozo, Niek J. Lopes [Science and Technology of Nuclear Fusion, Eindhoven University of Technology, Eindhoven 5612 AZ (Netherlands)

    2014-08-14T23:59:59.000Z

    Tungsten plasmas induced by unipolar arcs were investigated using optical emission spectroscopy and imaging, and compared with laser-induced tungsten plasmas. The unipolar arcs were initiated in the linear-plasma simulator PISCES-A at UCSD under fusion relevant conditions. The electron temperature and density of the unipolar arc plasmas were in the range 0.5–0.7?eV and 0.7–2.0?×?10{sup 20?}m{sup ?3}, respectively, and increased with increasing negative bias voltage, but did not correlate with the surface temperature. In comparison, the electron temperature and density of the laser-induced plasmas were in the range 0.6–1.4?eV and 7?×?10{sup 19}–1?×?10{sup 22?}m{sup ?3}, respectively.

  8. Arc initiation in cathodic arc plasma sources

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA)

    2002-01-01T23:59:59.000Z

    A "triggerless" arc initiation method and apparatus is based on simply switching the arc supply voltage to the electrodes (anode and cathode). Neither a mechanical trigger electrode nor a high voltage flashover from a trigger electrode is required. A conducting path between the anode and cathode is provided, which allows a hot spot to form at a location where the path connects to the cathode. While the conductive path is eroded by the cathode spot action, plasma deposition ensures the ongoing repair of the conducting path. Arc initiation is achieved by simply applying the relatively low voltage of the arc power supply, e.g. 500 V-1 kV, with the insulator between the anode and cathode coated with a conducting layer and the current at the layer-cathode interface concentrated at one or a few contact points. The local power density at these contact points is sufficient for plasma production and thus arc initiation. A conductive surface layer, such as graphite or the material being deposited, is formed on the surface of the insulator which separates the cathode from the anode. The mechanism of plasma production (and arc initiation) is based on explosive destruction of the layer-cathode interface caused by joule heating. The current flow between the thin insulator coating and cathode occurs at only a few contact points so the current density is high.

  9. Method of synthesizing tungsten nanoparticles

    SciTech Connect (OSTI)

    Thoma, Steven G; Anderson, Travis M

    2013-02-12T23:59:59.000Z

    A method to synthesize tungsten nanoparticles has been developed that enables synthesis of nanometer-scale, monodisperse particles that can be stabilized only by tetrahydrofuran. The method can be used at room temperature, is scalable, and the product concentrated by standard means. Since no additives or stabilizing surfactants are required, this method is particularly well suited for producing tungsten nanoparticles for dispersion in polymers. If complete dispersion is achieved due to the size of the nanoparticles, then the optical properties of the polymer can be largely maintained.

  10. Arc Position Sensing Technology

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

    arc remelting (VAR) furnaces for industries that use specialty metals such as nickel, titanium, and zirconium. The technology could be used to help produce materials with stronger...

  11. TEMPORARILY ALLOYING TITANIUM TO FACILITATE FRICTION STIR WELDING

    SciTech Connect (OSTI)

    Hovanski, Yuri

    2009-05-06T23:59:59.000Z

    While historically hydrogen has been considered an impurity in titanium, when used as a temporary alloying agent it promotes beneficial changes to material properties that increase the hot-workability of the metal. This technique known as thermohydrogen processing was used to temporarily alloy hydrogen with commercially pure titanium sheet as a means of facilitating the friction stir welding process. Specific alloying parameters were developed to increase the overall hydrogen content of the titanium sheet ranging from commercially pure to 30 atomic percent. Each sheet was evaluated to determine the effect of the hydrogen content on process loads and tool deformation during the plunge phase of the friction stir welding process. Two materials, H-13 tool steel and pure tungsten, were used to fabricate friction stir welding tools that were plunged into each of the thermohydrogen processed titanium sheets. Tool wear was characterized and variations in machine loads were quantified for each tool material and weld metal combination. Thermohydrogen processing was shown to beneficially lower plunge forces and stabilize machine torques at specific hydrogen concentrations. The resulting effects of hydrogen addition to titanium metal undergoing the friction stir welding process are compared with modifications in titanium properties documented in modern literature. Such comparative analysis is used to explain the variance in resulting process loads as a function of the initial hydrogen concentration of the titanium.

  12. Process Of Bonding Copper And Tungsten

    DOE Patents [OSTI]

    Slattery, Kevin T. (St. Charles, MO); Driemeyer, Daniel E. (Manchester, MO)

    1999-11-23T23:59:59.000Z

    Process for bonding a copper substrate to a tungsten substrate by providing a thin metallic adhesion promoting film bonded to a tungsten substrate and a functionally graded material (FGM) interlayer bonding the thin metallic adhesion promoting film to the copper substrate. The FGM interlayer is formed by thermal plasma spraying mixtures of copper powder and tungsten powder in a varied blending ratio such that the blending ratio of the copper powder and the tungsten powder that is fed to a plasma torch is intermittently adjusted to provide progressively higher copper content/tungsten content, by volume, ratio values in the interlayer in a lineal direction extending from the tungsten substrate towards the copper substrate. The resulting copper to tungsten joint well accommodates the difference in the coefficient of thermal expansion of the materials.

  13. Accepted Manuscript Making Tungsten Work

    E-Print Network [OSTI]

    Raffray, A. René

    Thermonuclear Experimental Reactor Organization, Cadarache, FRANCE 3 Plasma Science and Fusion Center at MIT International Thermonuclear Experimental Reactor Organization, Cadarache, FRANCE 3 Plasma Science and Fusion Thermonuclear Experimental Reactor). Tungsten (W) is the plasma-facing material of choice in several design

  14. EVALUATION OF CONSTANT CURRENT WELD CONTROL FOR PINCH WELDING

    SciTech Connect (OSTI)

    Korinko, P; STANLEY, S; HOWARD, H

    2005-10-11T23:59:59.000Z

    Modern weld controllers typically use current to control the weld process. SRS uses a legacy voltage control method. This task was undertaken to determine if the improvements in the weld control equipment could be implemented to provide improvements to the process control. The constant current mode of operation will reduce weld variability by about a factor of 4. The constant voltage welds were slightly hotter than the constant current welds of the same nominal current. The control mode did not appear to adversely affect the weld quality, but appropriate current ranges need to be established and a qualification methodology for both welding and shunt calibrations needs to be developed and documented.

  15. Dual wire welding torch and method

    DOE Patents [OSTI]

    Diez, Fernando Martinez (Peoria, IL); Stump, Kevin S. (Sherman, IL); Ludewig, Howard W. (Groveland, IL); Kilty, Alan L. (Peoria, IL); Robinson, Matthew M. (Peoria, IL); Egland, Keith M. (Peoria, IL)

    2009-04-28T23:59:59.000Z

    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  16. Heat-treatment with induction heating of pipes within the pipe welding mill

    SciTech Connect (OSTI)

    Zgura, A.A.; Krichevskii, E.M.; Rudenko, V.A.; Lysyak, A.V.; Kumanev, V.A.

    1988-01-01T23:59:59.000Z

    The parameters of induction heat-treatment were determined for pipes from steels 10Kh18N10T and 12Kh18N10T. Mechanical properties of the base metal and the weld were determined by metallography. Induction heat treatment of corrosion-resistant steel pipes in the line of an argon-arc welding mill was found to produce a fine-grain structure of the base metal and weld, ensured that the mechanical properties satisfied all specifications, reduced time and consumption of the etching solution during chemical processing, required no additional personnel, reduced oxidation of the metal and saved energy.

  17. Diffusion of tungsten clusters on tungsten (110) surface

    SciTech Connect (OSTI)

    Chen, Dong; Hu, Wangyu; Yang, Jianyu; Deng, Huiqiu; Sun, Lixian; Gao, Fei

    2009-04-01T23:59:59.000Z

    Using molecular dynamics simulation and modified analytic embedded-atom method, we have investigated the self-diffusion of clusters on a tungsten (110) surface. As compared to the linear-chain configuration, the close-packed islands for tungsten clusters containing more than nine adatoms have been predicted to be more stable with the relatively lower binding energies. The migration energies show an interesting and oscillating behavior with increasing cluster size. The tetramer, hexamer and octamer have obviously higher migration energies than the others. The different atomic configurations and diffusion mechanisms have been determined during the diffusion processes. It is clear that the dimer-shearing mechanism occurs inside the hexamer, while it occurs at the periphery of heptamer. The successive hopping mechanism of individual atom is of critical importance in the migration of the clusters containing five or fewer adatoms. In addition, the diffusion of a cluster with nine adatoms is achieved through the changes of the cluster shape.

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

    SciTech Connect (OSTI)

    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

    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.

  19. Non-Vacuum Electron Beam Welding

    SciTech Connect (OSTI)

    Hershcovitch, Ady

    2007-01-31T23:59:59.000Z

    Original objectives of CRADA number BNL-01-03 between BNL and Acceleron, Inc., were to further develop the Plasma Window concept (a BNL invention covered by US Patent number 5,578,831), mate the Plasma Window to an existing electron beam welder to perform in-air electron beam welding, and mount the novel nonvacuum electron beam welder on a robot arm. Except for the last objective, all other goals were met or exceeded. Plasma Window design and operation was enhanced during the project, and it was successfully mated to a conventional4 kW electron beam welder. Unprecedented high quality non-vacuum electron beam . welding was demonstrated. Additionally, a new invention the Plasma Shield (US Patent number 7,075,030) that chemically and thermally shields a target object was set forth. Great interest in the new technology was shown by a number of industries and three arcs were sold for experimental use. However, the welding industry requested demonstration of high speed welding, which requires 100 kW electron beam welders. The cost of such a welder involved the need for additional funding. Therefore, some of the effort was directed towards Plasma Shield development. Although relatively a small portion of the R&D effort was spent on the Plasma Shield, some very encouraging results were obtained. Inair Plasma Shield was demonstrated. With only a partial shield, enhanced vacuum separation and cleaner welds were realized. And, electron beam propagation in atmosphere improved by a factor of about 3. Benefits to industry are the introduction of two new technologies. BNL benefited from licensing fee cash, from partial payment for employee salary, and from a new patent In addition to financial benefits, a new technology for physics studies was developed. Recommendations for future work are to develop an under-water plasma shield, perform welding with high-power electron beam:s, carry out other plasma shielded electron beam and laser processes. Potential benefits from further R&D are that various processes involving electron ion and laser beams that have now restrictions can, with the Plasma Shield be performed in practically any environment. For example, electron beam and laser welding can be performed under water, as well as, in situ repair of ship and nuclear reactor components. The plasma shield results in both thermal (since the plasma is hotter than the environment) and chemical shielding. The latter feature brings about in-vacuum process purity out of vacuum, and the thermal shielding aspect results in higher production rates.

  20. Characterization of tungsten films and their hydrogen permeability

    SciTech Connect (OSTI)

    Nemani?, Vincenc, E-mail: vincenc.nemanic@ijs.si; Kova?, Janez [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Lungu, Cristian; Porosnicu, Corneliu [National Institute for Laser, Plasma and Radiation Physics, NILPRP, Magurele, Bucharest 077125 (Romania); Zajec, Bojan [Slovenian National Building and Civil Engineering Institute, Dimi?eva 12, 1000 Ljubljana (Slovenia)

    2014-11-01T23:59:59.000Z

    Prediction of tritium migration and its retention within fusion reactors is uncertain due to a significant role of the structural disorder that is formed on the surface layer after plasma exposure. Tungsten films deposited by any of the suitable methods are always disordered and contain a high density of hydrogen traps. Experiments on such films with hydrogen isotopes present a suitable complementary method, which improves the picture of the hydrogen interaction with fusion relevant materials. The authors report on the morphology, composition, and structure of tungsten films deposited by the thermionic vacuum arc method on highly permeable Eurofer substrates. Subsequently, hydrogen permeation studies through these films were carried out in a wide pressure range from 20 to 1000 mbars at 400?°C. The final value of the permeation coefficient for four samples after 24?h at 400?°C was between P?=?3.2?×?10{sup ?14}?mol?H{sub 2}/(m?s?Pa{sup 0.5}) and P?=?1.1?×?10{sup ?15}?mol H{sub 2}/(m s Pa{sup 0.5}). From the time evolution of the permeation flux, it was shown that diffusivity was responsible for the difference in the steady fluxes, as solubility was roughly the same. This is confirmed by XRD data taken on these samples.

  1. MAIN APPLICATIONS Spot welding

    E-Print Network [OSTI]

    De Luca, Alessandro

    IRB 6400 MAIN APPLICATIONS Spot welding Press tending Material handling Machine tending Palletizing N Poke welding All IRB 6400R-versions have Foundry Plus protection. For details, see under manipulator 6400PE 1600 kg Others 2060 - 2390 kg ENVIRONMENT Ambient temperature Manipulator 5 ­ 50°C Relative

  2. A Well-Defined, Silica-Supported Tungsten Imido Alkylidene Olefin Metathesis Catalyst

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    deactivation. Keywords. Tungsten Imido Alkylidene complex.monosiloxy alkylidene tungsten surface complex syn-2, [(_

  3. Gamma Spectrum from Neutron Capture on Tungsten Isotopes

    E-Print Network [OSTI]

    Hurst, Aaron

    2011-01-01T23:59:59.000Z

    FROM NEUTRON CAPTURE ON TUNGSTEN ISOTOPES A. M. HURST ?1,2 ,capture on the stable tungsten isotopes is presented, withknown decay schemes of the tungsten isotopes from neutron

  4. Factors controlling tungsten concentrations in ground water, Carson Desert, Nevada

    E-Print Network [OSTI]

    Factors controlling tungsten concentrations in ground water, Carson Desert, Nevada Ralph L. Seiler sources. Tungsten concentrations in 100 ground water samples from all aquifers used as drinking water indicates that W exhibits Tungsten con- centrations are strongly and positively correlated

  5. Growth of Ordered Ultrathin Tungsten Oxide Films on Pt(111)....

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

    Growth of Ordered Ultrathin Tungsten Oxide Films on Pt(111). Growth of Ordered Ultrathin Tungsten Oxide Films on Pt(111). Abstract: Ordered tungsten oxide ultra-thin films were...

  6. Weld Results SUNY Stony Brook

    E-Print Network [OSTI]

    McDonald, Kirk

    Weld Results Yan Zhan SUNY Stony Brook June 13rd, 2013 1 #12;Outline · Studied Parameters · Results Analysis ­ Contours Plots For the Weld Region ­ Axial Velocity Profile at Different Locations Near the Weld ­ Plots of Turbulent Kinetic Energy and Momentum Thickness Near the Weld ­ Line Plot Goes From Inlet

  7. arc welding parameters: Topics by E-print Network

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

    and the software sophistication, economics, and availability of the MS-DOSWINDOWS environment. The main objective of the work, the design of a control system and its...

  8. arc welding system: Topics by E-print Network

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

    phased arrays is inspection speed: linear travel speeds of up to 100 mmsec are possible. Sizing is typically performed using diffraction approaches (TOFD and back diffraction),...

  9. Effects of Tungsten Oxide Addition on the Electrochemical Performance...

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

    Tungsten Oxide Addition on the Electrochemical Performance of Nanoscale Tantalum Oxide-Based Electrocatalysts for Effects of Tungsten Oxide Addition on the Electrochemical...

  10. Welding Process Fundamentals* Thomas W. Eagar and Aaron D. Mazzeo, Massachusetts Institute of Technology

    E-Print Network [OSTI]

    Eagar, Thomas W.

    (such as fastening, adhesive bonding, soldering, brazing, arc welding, diffusion bonding, and resistance the material surrounding it. Although some pro- cesses, such as diffusion bonding, can achieve results solids will bond if their surfaces are brought into intimate contact. One factor that generally inhibits

  11. Microstructure and Creep Strength of Welds in Advanced Ferritic Power Plant Steels

    E-Print Network [OSTI]

    Cambridge, University of

    Microstructure and Creep Strength of Welds in Advanced Ferritic Power Plant Steels Fujio ABE) power plant at 650 o C (923 K).1 Critical issues for the development of ferritic steels for 650 o C USC joints for tungsten-strengthened advanced 9-12%Cr steels, ASME-P92 (9Cr-0.5Mo-1.8W-VNb), ASME-P122 (11Cr

  12. WELDING RESEARCH -s55WELDING JOURNAL

    E-Print Network [OSTI]

    DuPont, John N.

    . This region was followed by a dual-phase austenite/martensite region near the in- terface between the grade steels and stainless steels still occur in many in- dustrial applications. These failures have generally between the carbon steel and stainless steel end members to permit the deposition of two similar welds

  13. Friction stir welding tool

    DOE Patents [OSTI]

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

    2008-04-15T23:59:59.000Z

    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.

  14. Investigation of electromagnetic welding

    E-Print Network [OSTI]

    Pressl, Daniel G. (Daniel Gerd)

    2009-01-01T23:59:59.000Z

    We propose several methodologies to study and optimize the electromagnetic process for Electromagnetic Forming (EMF) and Welding (EMW), thereby lowering the necessary process energy up to a factor of three and lengthening ...

  15. Concurrent ultrasonic weld evaluation system

    DOE Patents [OSTI]

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

    1987-12-15T23:59:59.000Z

    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.

  16. Concurrent ultrasonic weld evaluation system

    DOE Patents [OSTI]

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

    1985-09-04T23:59:59.000Z

    A system for concurrent, non-destructive evaluation of partially completed welds for use in conjunction with an automated welder. 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.

  17. College of Design ARC Architecture

    E-Print Network [OSTI]

    MacAdam, Keith

    College of Design ARC Architecture KEY: # = new course * = course changed = course dropped,landscape,andarchitecturalspaceswithattentiontotheirapplicationtothearchitecturalexperience.Studio:4hoursperweek. Prereq: Admission to the School of Architecture. ARC 102 DRAWING II: OBSERVATIONAL OF ARCHITECTURE. (3

  18. Certification of a weld produced by friction stir welding

    DOE Patents [OSTI]

    Obaditch, Chris; Grant, Glenn J

    2013-10-01T23:59:59.000Z

    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.

  19. High strength and density tungsten-uranium alloys

    DOE Patents [OSTI]

    Sheinberg, Haskell (Los Alamos, NM)

    1993-01-01T23:59:59.000Z

    Alloys of tungsten and uranium and a method for making the alloys. The amount of tungsten present in the alloys is from about 55 vol % to about 85 vol %. A porous preform is made by sintering consolidated tungsten powder. The preform is impregnated with molten uranium such that (1) uranium fills the pores of the preform to form uranium in a tungsten matrix or (2) uranium dissolves portions of the preform to form a continuous uranium phase containing tungsten particles.

  20. Physical properties of erbium implanted tungsten oxide films deposited by reactive dual magnetron sputtering

    E-Print Network [OSTI]

    Mohamed, Sodky H.; Anders, Andre

    2006-01-01T23:59:59.000Z

    of erbium implanted tungsten oxide films deposited byDual magnetron sputtering; tungsten oxide films; Er ionoptical waveguides [3,5]. Tungsten oxide (WO 3 ) thin films

  1. FINAL FOCUS ION BEAM INTENSITY FROM TUNGSTEN FOIL CALORIMETER AND SCINTILLATOR IN NDCX-I

    E-Print Network [OSTI]

    Lidia, S.M.

    2010-01-01T23:59:59.000Z

    FOCUS ION BEAM INTENSITY FROM TUNGSTEN FOIL CALORIMETER ANDtemperature rise in the tungsten foil. A cross-calibrationis obtained with a 3µm thick tungsten foil calorimeter and

  2. Robotic Welding and Inspection System

    SciTech Connect (OSTI)

    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

    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.

  3. Friction stir welding tool and process for welding dissimilar materials

    DOE Patents [OSTI]

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

    2013-05-07T23:59:59.000Z

    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.

  4. Crack growth rates of nickel alloy welds in a PWR environment.

    SciTech Connect (OSTI)

    Alexandreanu, B.; Chopra, O. K.; Shack, W. J.; Energy Technology

    2006-05-31T23:59:59.000Z

    In light water reactors (LWRs), vessel internal components made of nickel-base alloys are susceptible to environmentally assisted cracking. A better understanding of the causes and mechanisms of this cracking may permit less conservative estimates of damage accumulation and requirements on inspection intervals. A program is being conducted at Argonne National Laboratory to evaluate the resistance of Ni alloys and their welds to environmentally assisted cracking in simulated LWR coolant environments. This report presents crack growth rate (CGR) results for Alloy 182 shielded-metal-arc weld metal in a simulated pressurized water reactor (PWR) environment at 320 C. Crack growth tests were conducted on 1-T compact tension specimens with different weld orientations from both double-J and deep-groove welds. The results indicate little or no environmental enhancement of fatigue CGRs of Alloy 182 weld metal in the PWR environment. The CGRs of Alloy 182 in the PWR environment are a factor of {approx}5 higher than those of Alloy 600 in air under the same loading conditions. The stress corrosion cracking for the Alloy 182 weld is close to the average behavior of Alloy 600 in the PWR environment. The weld orientation was found to have a profound effect on the magnitude of crack growth: cracking was found to propagate faster along the dendrites than across them. The existing CGR data for Ni-alloy weld metals have been compiled and evaluated to establish the effects of key material, loading, and environmental parameters on CGRs in PWR environments. The results from the present study are compared with the existing CGR data for Ni-alloy welds to determine the relative susceptibility of the specific Ni-alloy weld to environmentally enhanced cracking.

  5. Automotive Research Center (ARC) "The Automotive Research Center (ARC) develops simulation and modeling tools for discovering

    E-Print Network [OSTI]

    Kamat, Vineet R.

    Automotive Research Center (ARC) "The Automotive Research Center (ARC) develops simulation with industry to leverage and transfer the efforts and results http://arc.engin.umich.edu/ #12;

  6. Weld penetration and defect control

    SciTech Connect (OSTI)

    Chin, B.A.

    1992-05-15T23:59:59.000Z

    Highly engineered designs increasingly require the use of improved materials and sophisticated manufacturing techniques. To obtain optimal performance from these engineered products, improved weld properties and joint reliability are a necessarily. This requirement for improved weld performance and reliability has led to the development of high-performance welding systems in which pre-programmed parameters are specified before any welding takes place. These automated systems however lack the ability to compensate for perturbations which arise during the welding process. Hence the need for systems which monitor and control the in-process status of the welding process. This report discusses work carried out on weld penetration indicators and the feasibility of using these indicators for on-line penetration control.

  7. Method and apparatus for assessing weld quality

    DOE Patents [OSTI]

    Smartt, Herschel B. (Idaho Falls, ID); Kenney, Kevin L. (Idaho Falls, ID); Johnson, John A. (Idaho Falls, ID); Carlson, Nancy M. (Idaho Falls, ID); Clark, Denis E. (Idaho Falls, ID); Taylor, Paul L. (Boise, ID); Reutzel, Edward W. (State College, PA)

    2001-01-01T23:59:59.000Z

    Apparatus for determining a quality of a weld produced by a welding device according to the present invention includes a sensor operatively associated with the welding device. The sensor is responsive to at least one welding process parameter during a welding process and produces a welding process parameter signal that relates to the at least one welding process parameter. A computer connected to the sensor is responsive to the welding process parameter signal produced by the sensor. A user interface operatively associated with the computer allows a user to select a desired welding process. The computer processes the welding process parameter signal produced by the sensor in accordance with one of a constant voltage algorithm, a short duration weld algorithm or a pulsed current analysis module depending on the desired welding process selected by the user. The computer produces output data indicative of the quality of the weld.

  8. WELDING RESEARCH ~~--------------~~~ SUPPLEMENT TO THE WELDING JOURNAL, MAY 1990

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) WELDING RESEARCH ~~--------------~~~ SUPPLEMENT TO THE WELDING JOURNAL, MAY 1990 Sponsored by the American Welding Society and the Welding Research Council All papers published in the Welding Journal's Welding Research Supplement undergo Peer Review before publication for: 1) originality of the contribution

  9. Masatsu kakuhan setsugo "Friction Stir Welding Complete aspects of FSW" Japan Welding Society

    E-Print Network [OSTI]

    Cambridge, University of

    Masatsu kakuhan setsugo ­ "Friction Stir Welding ­ Complete aspects of FSW" Japan Welding Society years ago that the Friction Stir Welding (FSW) method was proposed by TWI. Because FSW is a solid state welding method, the peak temperature reached during FSW welding is lower than the traditional welding

  10. Method for welding chromium molybdenum steels

    DOE Patents [OSTI]

    Sikka, Vinod K. (Clinton, TN)

    1986-01-01T23:59:59.000Z

    Chromium-molybdenum steels exhibit a weakening after welding in an area adjacent to the weld. This invention is an improved method for welding to eliminate the weakness by subjecting normalized steel to a partial temper prior to welding and subsequently fully tempering the welded article for optimum strength and ductility.

  11. Toolbox Safety Talk Welding & Metal Work Safety

    E-Print Network [OSTI]

    Pawlowski, Wojtek

    Toolbox Safety Talk Welding & Metal Work Safety Environmental Health & Safety Facilities Safety or harmful emission giving metals. Welding Safety When welding outside of a designated welding booth, ensure injury. Avoid welding on materials such as galvanized or stainless steel in order to minimize toxic fume

  12. Shell Hoop Prestress Generated by Welding

    E-Print Network [OSTI]

    Meuser, R.B.

    2011-01-01T23:59:59.000Z

    can be generated by the welding process. The data are notagainst the yoke for welding. TEST SETUP Annealed Type 304in two passes using TIG welding. After strain measurements

  13. Growth of tungsten oxide on carbon nanowalls templates

    SciTech Connect (OSTI)

    Wang, Hua, E-mail: wanghua@dlou.edu.cn [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); College of Fisheries and Life Science, Dalian Ocean University, Dalian 116023 (China); Su, Yan [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Chen, Shuo, E-mail: shuochen@dlut.edu.cn [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Quan, Xie [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China)

    2013-03-15T23:59:59.000Z

    Highlights: ? Tungsten oxide deposited on carbon nanowalls by hot filament chemical vapor deposition technique. ? This composite has two-dimensional uniform morphology with a crystalline structure of monoclinic tungsten trioxide. ? Surface photoelectric voltage measurements show that this product has photoresponse properties. - Abstract: In the present work we present a simple approach for coupling tungsten oxide with carbon nanowalls. The two-dimensional carbon nanowalls with open boundaries were grown using plasma enhanced hot filament chemical vapor deposition, and the subsequent tungsten oxide growth was performed in the same equipment by direct heating of a tungsten filament. The tungsten oxide coating is found to have uniform morphology with a crystalline structure of monoclinic tungsten trioxide. Surface photoelectric voltage measurements show that this product has photoresponse properties. The method of synthesis described here provides an operable route to the production of two-dimensional tungsten oxide nanocomposites.

  14. Arc Position Sensing

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProductsAlternativeOperational Management » History »Dept ofY-12Arah SchuurArc

  15. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: In 1998, little if any tungsten concentrate was produced from U.S. mines.

    E-Print Network [OSTI]

    184 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: In 1998, little if any tungsten concentrate was produced from U.S. mines. Approximately 10 companies in the United States processed tungsten concentrates, ammonium paratungstate, tungsten oxide, and

  16. Element 74, the Wolfram Versus Tungsten Controversy

    SciTech Connect (OSTI)

    Holden,N.E.

    2008-08-11T23:59:59.000Z

    Two and a quarter centuries ago, a heavy mineral ore was found which was thought to contain a new chemical element called heavy stone (or tungsten in Swedish). A few years later, the metal was separated from its oxide and the new element (Z=74) was called wolfram. Over the years since that time, both the names wolfram and tungsten were attached to this element in various countries. Sixty years ago, IUPAC chose wolfram as the official name for the element. A few years later, under pressure from the press in the USA, the alternative name tungsten was also allowed by IUPAC. Now the original, official name 'wolfram' has been deleted by IUPAC as one of the two alternate names for the element. The history of this controversy is described here.

  17. TUNGSTEN--2000 81.1 By Kim B. Shedd

    E-Print Network [OSTI]

    TUNGSTEN--2000 81.1 TUNGSTEN By Kim B. Shedd Domestic survey data and tables were prepared by Jason T. Collins, statistical assistant, and the world production table was prepared by Glenn J. Wallace, international data coordinator. Tungsten is a whitish-gray metal with many unique properties and a wide variety

  18. Robotic weld overlay coatings for erosion control. Final technical progress report, July 1992--July 1995

    SciTech Connect (OSTI)

    Levin, B.F.; DuPont, J.N.; Marder, A.R.

    1995-10-15T23:59:59.000Z

    The erosion behavior of weld overlay coatings has been studied. Eleven weld overlay alloys were deposited on 1018 steel substrates using the plasma arc welding process and erosion tested at 400{degrees}C at 90{degrees} and 30{degrees} particle impact angles. The microstructure of each coating was characterized before erosion testing. A relative ranking of the coatings erosion resistance was developed by determining the steady state erosion rates. Ultimet, Inconel-625, and 316L SS coatings showed the best erosion resistance at both impact angles. It was found that weld overlays that exhibit good abrasion resistance did not show good erosion resistance. Erosion tests were also performed for selected wrought materials with chemical composition similar to weld overlays. Eroded surfaces of the wrought and weld alloys were examined by Scanning Electron Microscopy (SEM). Microhardness tests were performed on the eroded samples below the erosion surface to determine size of the plastically deformed region. It was found that one group of coatings experienced significant plastic deformation as a result of erosion while the other did not. It was also established that, in the steady state erosion regime, the size of the plastically deformed region is constant.

  19. Cathodic Vacuum Arc Plasma of Thallium

    E-Print Network [OSTI]

    Yushkov, Georgy Yu.; Anders, Andre

    2006-01-01T23:59:59.000Z

    P. J. Martin, Handbook of Vacuum Arc Science and Technology.charge state distributions of vacuum arc plasmas: The originand the broadening of vacuum-arc ion charge state

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

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ( 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 of material variations and weld process parameter modifications on resistance spot welding of coated

  1. Arc fault detection system

    DOE Patents [OSTI]

    Jha, Kamal N. (Bethel Park, PA)

    1999-01-01T23:59:59.000Z

    An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.

  2. Arc fault detection system

    DOE Patents [OSTI]

    Jha, K.N.

    1999-05-18T23:59:59.000Z

    An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard. 1 fig.

  3. Science Arts & Mtiers (SAM) is an open access repository that collects the work of Arts et Mtiers ParisTech

    E-Print Network [OSTI]

    are difficult to perform and the manufacturing process that is most commonly used is gas tungsten arc welding for joining magnesium alloys as it presents a low and pre- cise heat input, high welding speed and a small BARRALLIER - Texture evolution in Nd:YAG-laser welds of AZ31 magnesium alloy hot rolled sheets and its

  4. WELDING AND CUTTING 10.A GENERAL

    E-Print Network [OSTI]

    US Army Corps of Engineers

    EM 385-1-1 XX Jun 13 10-1 SECTION 10 WELDING AND CUTTING 10.A GENERAL 10.A.01 Welders, cutters, and their supervisor shall be trained in the safe operation of their equipment, safe welding/cutting practices, and welding/cutting respiratory and fire protection. > AIHA publication "Welding Health and Safety: A Field

  5. Tungsten Divertor Erosion in all Metal Devices: Lessons from the ITER-Like Wall of JET and the All Tungsten ASDEX Upgrade

    E-Print Network [OSTI]

    Tungsten Divertor Erosion in all Metal Devices: Lessons from the ITER-Like Wall of JET and the All Tungsten ASDEX Upgrade

  6. Assessing Exposures to Particulate Matter and Manganese in Welding Fumes

    E-Print Network [OSTI]

    LIU, SA

    2010-01-01T23:59:59.000Z

    465.   Sapp ME.  A History of Welding: from Hepheastus to whistoryfolder/welding/index.html.   Saric M, Markicevic, be retrieved from American Welding Society publications. The

  7. Laser welding of fused quartz

    DOE Patents [OSTI]

    Piltch, Martin S.; Carpenter, Robert W.; Archer III, McIlwaine

    2003-06-10T23:59:59.000Z

    Refractory materials, such as fused quartz plates and rods are welded using a heat source, such as a high power continuous wave carbon dioxide laser. The radiation is optimized through a process of varying the power, the focus, and the feed rates of the laser such that full penetration welds may be accomplished. The process of optimization varies the characteristic wavelengths of the laser until the radiation is almost completely absorbed by the refractory material, thereby leading to a very rapid heating of the material to the melting point. This optimization naturally occurs when a carbon dioxide laser is used to weld quartz. As such this method of quartz welding creates a minimum sized heat-affected zone. Furthermore, the welding apparatus and process requires a ventilation system to carry away the silicon oxides that are produced during the welding process to avoid the deposition of the silicon oxides on the surface of the quartz plates or the contamination of the welds with the silicon oxides.

  8. Evaluation of a portable x-ray fluorescence survey meter for the quantitative determination of trace metals in welding fumes

    E-Print Network [OSTI]

    Fehrenbacher, Mary Catherine

    1984-01-01T23:59:59.000Z

    Spectrometry Sensitivity Excitation Sources 12 16 Spectrometers and Detectors SHIELDED METAL ARC WELDING Health Effects of Welding THE PORTABLE X ? RAY FLUORESCENCE SURVEY METER METHODOLOGY RESULTS DISCUSSION OF RESULTS CAELUS I QblS RECQvfvt... Appendix C Basic Principle of AAS VITA Page 65 66 67 68 76 84 V1 11 LIST OF FIGURES Page 1. Transitions giving x-radiation 2. Fluorescent yield 3. Interaction of x-rays with matter 4. Particle size effects on x-ray intensity. . . 15 5...

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

    SciTech Connect (OSTI)

    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

    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.

  10. Formation of metal oxides by cathodic arc deposition

    SciTech Connect (OSTI)

    Anders, S.; Anders, A.; Rubin, M.; Wang, Z.; Raoux, S.; Kong, F.; Brown, I.G.

    1995-03-01T23:59:59.000Z

    Metal oxide thin films are of interest for a number of applications. Cathodic arc deposition, an established, industrially applied technique for formation of nitrides (e.g. TiN), can also be used for metal oxide thin film formation. A cathodic arc plasma source with desired cathode material is operated in an oxygen atmosphere, and metal oxides of various stoichiometric composition can be formed on different substrates. We report here on a series of experiments on metal oxide formation by cathodic arc deposition for different applications. Black copper oxide has been deposited on ALS components to increase the radiative heat transfer between the parts. Various metal oxides such as tungsten oxide, niobium oxide, nickel oxide and vanadium oxide have been deposited on ITO glass to form electrochromic films for window applications. Tantalum oxide films are of interest for replacing polymer electrolytes. Optical waveguide structures can be formed by refractive index variation using oxide multilayers. We have synthesized multilayers of Al{sub 2}O{sub 3}/Y{sub 2}O{sub 3}/AI{sub 2}O{sub 3}/Si as possible basic structures for passive optoelectronic integrated circuits, and Al{sub 2-x}Er{sub x}O{sub 3} thin films with a variable Er concentration which is a potential component layer for the production of active optoelectronic integrated devices such as amplifiers or lasers at a wavelength of 1.53 {mu}m. Aluminum and chromium oxide films have been deposited on a number of substrates to impart improved corrosion resistance at high temperature. Titanium sub-oxides which are electrically conductive and corrosion resistant and stable in a number of aggressive environments have been deposited on various substrates. These sub-oxides are of great interest for use in electrochemical cells.

  11. Assessing Exposures to Particulate Matter and Manganese in Welding Fumes

    E-Print Network [OSTI]

    LIU, SA

    2010-01-01T23:59:59.000Z

    less hazardous compared to MIG welding, these areas as wellareas where high concentrations occurred; 3) although resistance welding is considered less hazardoushazardous welding operations such as resistance welding should also be effectively controlled. Those who work in areas

  12. Controlled nanostructuration of polycrystalline tungsten thin films

    SciTech Connect (OSTI)

    Girault, B. [Institut P' (UPR 3346 CNRS), Universite de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Institut de Recherche en Genie Civil et Mecanique (UMR CNRS 6183), LUNAM Universite, Universite de Nantes, Centrale Nantes, CRTT, 37 Bd de l'Universite, BP 406, 44602 Saint-Nazaire Cedex (France); Eyidi, D.; Goudeau, P.; Guerin, P.; Bourhis, E. Le; Renault, P.-O. [Institut P' (UPR 3346 CNRS), Universite de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Sauvage, T. [CEMHTI/CNRS (UPR 3079 CNRS), Universite d'Orleans, 3A rue de la Ferollerie, 45071 Orleans Cedex 2 (France)

    2013-05-07T23:59:59.000Z

    Nanostructured tungsten thin films have been obtained by ion beam sputtering technique stopping periodically the growing. The total thickness was maintained constant while nanostructure control was obtained using different stopping periods in order to induce film stratification. The effect of tungsten sublayers' thicknesses on film composition, residual stresses, and crystalline texture evolution has been established. Our study reveals that tungsten crystallizes in both stable {alpha}- and metastable {beta}-phases and that volume proportions evolve with deposited sublayers' thicknesses. {alpha}-W phase shows original fiber texture development with two major preferential crystallographic orientations, namely, {alpha}-W<110> and unexpectedly {alpha}-W<111> texture components. The partial pressure of oxygen and presence of carbon have been identified as critical parameters for the growth of metastable {beta}-W phase. Moreover, the texture development of {alpha}-W phase with two texture components is shown to be the result of a competition between crystallographic planes energy minimization and crystallographic orientation channeling effect maximization. Controlled grain size can be achieved for the {alpha}-W phase structure over 3 nm stratification step. Below, the {beta}-W phase structure becomes predominant.

  13. Tungsten-dependent formaldehyde ferredoxin oxidoreductase: Reaction mechanism from quantum chemical calculations

    E-Print Network [OSTI]

    Liao, Rongzhen

    Tungsten-dependent formaldehyde ferredoxin oxidoreductase: Reaction mechanism from quantum chemical theory Enzyme catalysis Formaldehyde ferredoxin oxidoreductase from Pyrococcus furiosus is a tungsten the formaldehyde substrate binds directly to the tungsten ion. WVI =O then performs a nucleophilic attack

  14. Molybdenum and Tungsten Monoalkoxide Pyrrolide (MAP) Alkylidene Complexes That Contain a 2,6-Dimesitylphenylimido

    E-Print Network [OSTI]

    Müller, Peter

    Molybdenum and Tungsten Monoalkoxide Pyrrolide (MAP) Alkylidene Complexes That Contain a 2 ABSTRACT: Molybdenum and tungsten bispyrrolide alkyli- dene complexes that contain a 2 those that contain 2,5-dimethylpyrro- lide are pyridine free. Molybdenum and tungsten MAP 2

  15. Investigation of coronal plasma dynamics in tungsten and carbon X-pinches

    E-Print Network [OSTI]

    Madden, Robert Edward

    2008-01-01T23:59:59.000Z

    Coronal Plasma Dynamics in Tungsten and Carbon X-pinches ACoronal Plasma Dynamics in Tungsten and Carbon X-pinches byformation in 2- and 4-wire tungsten x-pinches using an 80

  16. CRITICAL FIELD FOR SUPERCONDUCTIVITY AND LOW-TEMPERATURE NORMAL-STATE HEAT CAPACITY OF TUNGSTEN

    E-Print Network [OSTI]

    Triplett, B.B.

    2008-01-01T23:59:59.000Z

    NORMAL-STATE HEAT CAPACITY OF TUNGSTEN B. B. Triplett, N. E.State Heat Capacity of Tungsten* B. n. Triplett,t N. E.I. ;\\feasurement Properties of tungsten sa~ples. ~feasured

  17. THE As-QUENCHED MICROSTRUCTURE AND TEMPERING BEHAVIOR OF RAPIDLY SOLIDIFIED TUNGSTEN STEELS

    E-Print Network [OSTI]

    Rayment, J.J.

    2014-01-01T23:59:59.000Z

    of six ternary iron-tungsten-carbon alloys and commercialFeWCS-6 (20 and 23wt% tungsten) only the cellular micro-microstructure of the higher tungsten alloys. Selected area

  18. Dynamic Characterization of Spot Welds

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

    modes, and fail more often under impact? - What are the roles of alloy composition and welding parameters in the change in failure mode? - What would it take to have crash model...

  19. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: In 1997, little if any tungsten concentrate was produced from U.S. mines.

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production in a significant decrease in mine production. The amount of tungsten concentrates remaining in stockpiles in China for the tungsten industry. Once the stockpiles are depleted, world mine production will have to increase to meet

  20. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: Limited shipments of tungsten concentrates were made from a California mine in

    E-Print Network [OSTI]

    178 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and primary products, wrought and unwrought tungsten, and waste and scrap: China, 43%; Germany, 11%; Canada,630 1,450 Events, Trends, and Issues: World tungsten supply was dominated by Chinese production

  1. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: A tungsten mine in California produced concentrates in 2012. Approximately eight

    E-Print Network [OSTI]

    176 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and concentrates, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 45,200 3,630 1,610 Events, Trends, and Issues: World tungsten supply was dominated by Chinese production

  2. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: One mine in California produced tungsten concentrates in 2010. Approximately

    E-Print Network [OSTI]

    176 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production. Import Sources (2006­09): Tungsten contained in ores and concentrates, intermediate and primary products, Trends, and Issues: World tungsten supply is dominated by Chinese production and exports. China

  3. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: A mine in California produced tungsten concentrates in 2009. Approximately eight

    E-Print Network [OSTI]

    176 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production. Import Sources (2005-08): Tungsten contained in ores and concentrates, intermediate and primary products, and Issues: World tungsten supply was dominated by Chinese production and exports. China's Government limited

  4. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: A mine in California restarted operations and made its first shipment of tungsten

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and primary products, wrought and unwrought tungsten, and waste and scrap: China, 43%; Canada, 16%; Germany, 9 by Chinese production and exports. China's Government restricted the amounts of tungsten that could

  5. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded production of tungsten concentrates in the United States was in

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded production of tungsten concentrates in the United States was in 1994 of ores and concentrates, intermediate and primary products, wrought and unwrought tungsten, and waste

  6. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded production of tungsten concentrates in the United States was in

    E-Print Network [OSTI]

    178 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded production of tungsten concentrates in the United States was in 1994. In 2000, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 39%; Russia, 21

  7. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: A tungsten mine in California produced concentrates in 2013. Approximately eight

    E-Print Network [OSTI]

    174 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and concentrates, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 45,100 2,300 2,240 Events, Trends, and Issues: World tungsten supply was dominated by Chinese production

  8. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: One mine in California produced tungsten concentrates in 2011. Approximately

    E-Print Network [OSTI]

    176 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production (2007­10): Tungsten contained in ores and concentrates, intermediate and primary products, wrought: World tungsten supply is dominated by Chinese production and exports. China's Government regulates its

  9. Tungsten Cluster Migration on Nanoparticles: Minimum Energy Pathway...

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

    Pathway and Migration Mechanism. Tungsten Cluster Migration on Nanoparticles: Minimum Energy Pathway and Migration Mechanism. Abstract: Transition state searches have been...

  10. alkaline tungsten matrix: Topics by E-print Network

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

    Thermonuclear Experimental Reactor Organization, Cadarache, FRANCE 3 Plasma Science and Fusion Thermonuclear Experimental Reactor). Tungsten (W) is the plasma-facing material of...

  11. anthocyanins facilitate tungsten: Topics by E-print Network

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

    Thermonuclear Experimental Reactor Organization, Cadarache, FRANCE 3 Plasma Science and Fusion Thermonuclear Experimental Reactor). Tungsten (W) is the plasma-facing material of...

  12. aluminum weld strength: Topics by E-print Network

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

    Repository Summary: Damping and Dynamic Modulus Measurements in Alumina and Tungsten Fibre-Reinforced Aluminium Composites. the damping capacity of aluminum tungsten fiber...

  13. High pressure neon arc lamp

    DOE Patents [OSTI]

    Sze, Robert C.; Bigio, Irving J.

    2003-07-15T23:59:59.000Z

    A high pressure neon arc lamp and method of using the same for photodynamic therapies is provided. The high pressure neon arc lamp includes a housing that encloses a quantity of neon gas pressurized to about 500 Torr to about 22,000 Torr. At each end of the housing the lamp is connected by electrodes and wires to a pulse generator. The pulse generator generates an initial pulse voltage to breakdown the impedance of the neon gas. Then the pulse generator delivers a current through the neon gas to create an electrical arc that emits light having wavelengths from about 620 nanometers to about 645 nanometers. A method for activating a photosensitizer is provided. Initially, a photosensitizer is administered to a patient and allowed time to be absorbed into target cells. Then the high pressure neon arc lamp is used to illuminate the target cells with red light having wavelengths from about 620 nanometers to about 645 nanometers. The red light activates the photosensitizers to start a chain reaction that may involve oxygen free radicals to destroy the target cells. In this manner, a high pressure neon arc lamp that is inexpensive and efficiently generates red light useful in photodynamic therapy is provided.

  14. Synthesis of Molybdenum and Tungsten Alkylidene Complexes That Contain Sterically Demanding Arenethiolate Ligands

    E-Print Network [OSTI]

    Müller, Peter

    Synthesis of Molybdenum and Tungsten Alkylidene Complexes That Contain Sterically Demanding,4 we decided to explore some arylthiolate analogues of terphenoxide molybde- num imido and tungsten

  15. An experimental method for investigating phase transformations in the heat affected zone of welds using synchrotron radiation

    SciTech Connect (OSTI)

    Elmer, J.W.; Wong, J.; Froba, M.; Waide, P.A.; Larson, E.M.

    1995-05-26T23:59:59.000Z

    Although welding is an established technology used in many industrial settings, it is least understand terms of the phases that actually exist, the variation of their spatial disposition with time, and the rate of transformation from one phase to another at various thermal coordinates in the vicinity of the weld. With the availability of high flux and, more recently, high brightness synchrotron x-radiation sources, a number of diffraction and spectroscopic methods have been developed for structural characterization with improved spatial and temporal resolutions to enable in-situ measurements of phases under extreme temperature, pressure and other processing conditions not readily accessible with conventional sources. This paper describes the application of spatially resolved x-ray diffraction (SRXRD) for in-situ investigations of phase transformations in the heat affected zone (HAZ) of fusion welds. Results are presented for gas tungsten (GTA) welds in commercially pure titanium that show the existence of the high temperature bcc {beta}-phase in a 3.3 {plus_minus} 0.3 mm wide HA band adjacent to the liquid weld pool. Phase concentration profiles derived from the SRXRD data further show the co-existence of both the low temperature hcp ({alpha}-phase and the {beta}-phase in the partially, transformed region of the HA. These results represent the first direct observations of solid state phase transformations and mapping of phase boundaries in fusion welds. SRXRD experiments of this type are needed as experimental input for modeling of kinetics of phase transformations and microstructural evolution under the highly non-isothermal conditions produced during welding.

  16. MATHEHATICAL NODELING OF THE TEHPERATURE PROFILES AND WELD DILUTION IN ELECTROSLAG WELDING OF STEEL PLATES

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) ) MATHEHATICAL NODELING OF THE TEHPERATURE PROFILES AND WELD DILUTION IN ELECTROSLAG WELDING describes a calculation procedure for the detailed predic- tion of temperature profiles and weld dilution in the electroslag welding of mild steel plates. The temperature profiles in the liquid slag and the liquid metal

  17. Automatic monitoring of vibration welding equipment

    DOE Patents [OSTI]

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

    2014-10-14T23:59:59.000Z

    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.

  18. Tungsten silicide and tungsten polycide anisotropic dry etch process for highly controlled dimensions and profiles

    E-Print Network [OSTI]

    Bashir, Rashid

    dimensions and profiles R. Bashir,a),b) A. E. Kabir,b) F. Hebert,c) and C. Brackenb) National Semiconductors. In many applications a spacer needs to be formed on the polycide sidewall Fig. 1 . Undesirable undercutting can re- sult in nonideal spacer formation for further device fabrica- tion. Tungsten silicide

  19. Waste Heat Recovery – Submerged Arc Furnaces (SAF)

    E-Print Network [OSTI]

    O'Brien, T.

    2008-01-01T23:59:59.000Z

    Waste Heat Recovery- Submerged Arc Furnaces (SAF) Thomas O?Brien Recycled Energy Development, LLC tobrien@recycled-energy.com Submerged Arc Furnaces are used to produce high temperature alloys. These furnaces typically run at 3000oF using...

  20. TungsTen--2004 79. Referencesthatincludeasectionmark()arefoundintheInternet

    E-Print Network [OSTI]

    TungsTen--2004 79. Referencesthatincludeasectionmark(§)arefoundintheInternet ReferencesCitedsection. TungsTen ByKimB.shedd Domestic survey data and tables were prepared by Amy C. Tolcin, statistical assistant, and the world production table was prepared by Glenn J. Wallace, international data coordinator

  1. Pre-resistance-welding resistance check

    DOE Patents [OSTI]

    Destefan, Dennis E. (Broomfield, CO); Stompro, David A. (Idaho Falls, ID)

    1991-01-01T23:59:59.000Z

    A preweld resistance check for resistance welding machines uses an open circuited measurement to determine the welding machine resistance, a closed circuit measurement to determine the parallel resistance of a workpiece set and the machine, and a calculation to determine the resistance of the workpiece set. Any variation in workpiece set or machine resistance is an indication that the weld may be different from a control weld.

  2. Phase transformations in welded supermartensitic stainless steels

    E-Print Network [OSTI]

    Carrouge, Dominique

    - ferrite phase, and the development of a model to facilitate the choice of a suitable post-weld heat-treatment temperature. The microstructural examination of a variety of welds revealed the presence of retained ?-ferrite in dual-phase and grain... -coarsened HAZ regions. Under normal welding conditions, ?-ferrite retention was more pronounced in dual-phase HAZ and in molybdenum containing alloys. However, in multipass welds, ?-ferrite distribution was non-uniform as a result of reheating effects. A number...

  3. Kinetics of the decomposition of tungsten hexacarbonyl

    SciTech Connect (OSTI)

    Podoprigora, V.I.; Baev, A.K.

    1987-07-20T23:59:59.000Z

    A differential-flow apparatus is devised for the study of the kinetics of the thermal decomposition of volatile metal carbonyls under quasi-stationary conditions. The applicability of the general kinetic approach to the investigation of the thermodecomposition of carbonyl compounds and of the analysis of the experimental data on the basis of specific thermodecomposition rates was proved. Well-founded kinetic characteristics were obtained for the first time for the thermodecomposition of tungsten carbonyl in the kinetic region and under quasi-stationary pyrolysis conditions.

  4. Low temperature photoresponse of monolayer tungsten disulphide

    SciTech Connect (OSTI)

    Cao, Bingchen; Shen, Xiaonan; Shang, Jingzhi; Cong, Chunxiao; Yang, Weihuang; Eginligil, Mustafa, E-mail: yuting@ntu.edu.sg, E-mail: meginligil@ntu.edu.sg [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371 (Singapore); Yu, Ting, E-mail: yuting@ntu.edu.sg, E-mail: meginligil@ntu.edu.sg [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371 (Singapore); Department of Physics, Faculty of Science, National University of Singapore, Singapore, 117542 (Singapore); Graphene Research Centre, National University of Singapore, Singapore, 117546 (Singapore)

    2014-11-01T23:59:59.000Z

    High photoresponse can be achieved in monolayers of transition metal dichalcogenides. However, the response times are inconveniently limited by defects. Here, we report low temperature photoresponse of monolayer tungsten disulphide prepared by exfoliation and chemical vapour deposition (CVD) method. The exfoliated device exhibits n-type behaviour; while the CVD device exhibits intrinsic behaviour. In off state, the CVD device has four times larger ratio of photoresponse for laser on/off and photoresponse decay–rise times are 0.1 s (limited by our setup), while the exfoliated device has few seconds. These findings are discussed in terms of charge trapping and localization.

  5. Tungsten Mountain Geothermal Area | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit withTianlin Baxin HydropowerTrinity Thermal Systems JumpTrueTullahomaTungsten

  6. Laser Welding of Aluminum and Aluminum Alloys

    E-Print Network [OSTI]

    Eagar, Thomas W.

    .. ) 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, many aluminum alloys contain magnesium or zinc, which are easily vaporized and thereby form a plasma

  7. Selection of Processes for Welding Steel Rails

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ...._ _) Selection of Processes for Welding Steel Rails by N.S. Tsai* and T.W. Eagar* ABSTRACT 421 The advantages and limitations ofseveral conventional and prospective rail welding processes are reviewed with emphasis on the heat input rate, on joint preparation, on post weld grinding and on resultant metallurgical

  8. TRANSIENT THERMAL BEHAVIOR IN RESISTANCE SPOT WELDING

    E-Print Network [OSTI]

    Eagar, Thomas W.

    temperature response during resistance spot welding was measured and discussed with various process parameters that the measurement of temperature profiles developed during the welding process is very important in this respect composition on galvanized steel, the temperature distribution during welding was monitored in a one

  9. Energy Sources Used for Fusion Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) Energy Sources Used for Fusion Welding Thomas W. Eagar, Massachusetts Institute of Technology reliability. The Section "Fusion Welding Processes" in this Volume provides details about equipment and systems for the major fusion welding proc- esses. The purpose of this Section of the Volume is to discuss

  10. Contamination and solid state welds.

    SciTech Connect (OSTI)

    Mills, Bernice E.

    2007-05-01T23:59:59.000Z

    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.

  11. Melting efficiency in fusion welding

    SciTech Connect (OSTI)

    Fuerschbach, P.W.

    1991-01-01T23:59:59.000Z

    Basic to our knowledge of the science of welding is an understanding of the melting efficiency, which indicates how much of the heat deposited by the welding process is used to produce melting. Recent calorimetric studies of GTAW, PAW, and LBW processes have measured the net heat input to the part thereby quantifying the energy transfer efficiency and in turn permitting an accurate determination of the melting efficiency. It is indicated that the weld process variables can dramatically affect the melting efficiency. This limiting value is shown to depend on the weld heat flow geometry as predicted by analytical solutions to the heat flow equation and as demonstrated by the recent empirical data. A new dimensionless parameter is used to predict the melting efficiency and is shown to correlate extremely well with recent empirical data. This simple prediction methodology is notable because it requires only a knowledge of the weld schedule and the material properties in order to estimate melting efficiency. 22 refs., 16 figs.

  12. Material property evaluations of bimetallic welds, stainless steel saw fusion lines, and materials affected by dynamic strain aging

    SciTech Connect (OSTI)

    Rudland, D.; Scott, P.; Marschall, C.; Wilkowski, G. [Battelle Memorial Institute, Columbus, OH (United States)

    1997-04-01T23:59:59.000Z

    Pipe fracture analyses can often reasonably predict the behavior of flawed piping. However, there are material applications with uncertainties in fracture behavior. This paper summarizes work on three such cases. First, the fracture behavior of bimetallic welds are discussed. The purpose of the study was to determine if current fracture analyses can predict the response of pipe with flaws in bimetallic welds. The weld joined sections of A516 Grade 70 carbon steel to F316 stainless steel. The crack was along the carbon steel base metal to Inconel 182 weld metal fusion line. Material properties from tensile and C(T) specimens were used to predict large pipe response. The major conclusion from the work is that fracture behavior of the weld could be evaluated with reasonable accuracy using properties of the carbon steel pipe and conventional J-estimation analyses. However, results may not be generally true for all bimetallic welds. Second, the toughness of austenitic steel submerged-arc weld (SAW) fusion lines is discussed. During large-scale pipe tests with flaws in the center of the SAW, the crack tended to grow into the fusion line. The fracture toughness of the base metal, the SAW, and the fusion line were determined and compared. The major conclusion reached is that although the fusion line had a higher initiation toughness than the weld metal, the fusion-line J-R curve reached a steady-state value while the SAW J-R curve increased. Last, carbon steel fracture experiments containing circumferential flaws with periods of unstable crack jumps during steady ductile tearing are discussed. These instabilities are believed to be due to dynamic strain aging (DSA). The paper discusses DSA, a screening criteria developed to predict DSA, and the ability of the current J-based methodologies to assess the effect of these crack instabilities. The effect of loading rate on the strength and toughness of several different carbon steel pipes at LWR temperatures is also discussed.

  13. Laboratory experiments on arc deflection and instability

    SciTech Connect (OSTI)

    Zweben, S.; Karasik, M.

    2000-03-21T23:59:59.000Z

    This article describes experiments on arc deflection instability carried out during the past few years at the Princeton University Plasma Physics Laboratory (PPPL). The approach has been that of plasma physicists interested in arcs, but they believe these results may be useful to engineers who are responsible for controlling arc behavior in large electric steel furnaces.

  14. Corrosion and wear resistance of tungsten carbide-cobalt and tungsten carbide-cobalt-chromium thermal spray coatings

    SciTech Connect (OSTI)

    Quets, J.; Alford, J.R.

    1999-07-01T23:59:59.000Z

    Tungsten carbide thermal spray coatings provide wear surfaces to new and overhauled components for various industries. Their wear resistance is obtained by incorporating small tungsten carbide particles into a metal matrix. This presentation will show what parameters influence their corrosion resistance in the ASTM B-117 Salt Spray Corrosion Test,

  15. Metal vapor arc ion plating

    DOE Patents [OSTI]

    Bertram, L.A.; Fisher, R.W.; Mattox, D.M.; Zanner, F.J.

    1986-09-09T23:59:59.000Z

    A method and apparatus for ion plating are described. The apparatus uses more negative than a first electrode voltage in a vacuum arc remelt system to attract low energy ions from the anode electrode to the article to be plated. 2 figs.

  16. Microstructural analysis of a single pass 2.25% Cr-1.0% Mo steel weld metal with different manganese contents

    SciTech Connect (OSTI)

    Guimares de Souza, Luis Felipe [Centro Federal de Educacao Tecnologica Celso Suckow da Fonseca (CEFET-RJ), Av. Maracana, 229, Rio de Janeiro, RJ, 20271-110 (Brazil); Souza Bott, Ivani de [Pontificia Universidade Catolica (PUC-RIO), R. Marques de SaoVicente, 225, Rio de Janeiro, RJ, 22453-900 (Brazil); Ferreira Jorge, Jorge Carlos [Centro Federal de Educacao Tecnologica Celso Suckow da Fonseca (CEFET-RJ), Av. Maracana, 229, Rio de Janeiro, RJ, 20271-110 (Brazil); Sauer Guimaraes, Ari [Universidade Federal do Rio de Janeiro (COPPE/UFRJ), Caixa Postal 68.505, Cidade Universitaria, Ilha do Fundao, RJ, 21945-970 (Brazil); Pinheiro Rocha Paranhos, Ronaldo [Universidade Estadual do Norte Fluminense (UENF), Av. Alberto Lamego, 2000, Campos, RJ, 28013-602 (Brazil)]. E-mail: paranhos@uenf.br

    2005-07-15T23:59:59.000Z

    Weld metals of the 2.25% Cr-1.0% Mo type with 0.84%, 1.21% and 2.3% Mn produced by submerged-arc welding were analyzed in the as-welded (AW), post weld heat treatment (PWHT) and PWHT followed by step-cooling (SC) heat treatment conditions. Fracture surface analysis revealed an evolution in the mode of fracture due to Mn content variations and heat treatment conditions, the occurrence of intergranular fracture being observed in welds with 2.30% Mn that were step-cooled. Transmission electron microscopy revealed that the microstructure was predominantly composed of bainite, although martensite was also observed for high Mn contents. A marked carbide precipitation was observed, preferentially at grain boundaries. This could be attributed to the SC heat treatment and associated with the embrittlement. However, the application of a de-embrittlement heat treatment to this step cooled weld metal has proved efficient, because the impact energy levels after this heat treatment surpassed those obtained in the stress relieved condition. This indicates that segregation of impurities to grain boundaries was responsible for the low impact energy levels observed after SC of weld metal containing > 0.84% Mn.

  17. Calorimetric measurements of energy transfer efficiency and melting efficiency in CO sub 2 laser beam welding

    SciTech Connect (OSTI)

    Fuerschbach, P.W.

    1990-01-01T23:59:59.000Z

    Our previous calorimetric studies of weld melting efficiency and arc efficiency in the GTAW and PAW processes have naturally led us to speculate as to the magnitude of the efficiencies in the LBW process which to data have also not been adequately investigated. Most welding engineers that have had experience with the LBW process are acutely aware that the metals' absorptivity, the surface finish, and the laser wavelength, all play an important role in affecting the energy transfer efficiency, but the extent of their influence and our understanding of the influence of other process variables is not well understood. In addition, it is widely thought that only the LBW or EBW processes can be selected for applications where thermal damage and distortion from the welding process must be kept to a minimum. For these reasons, we have looked forward to performing these calorimetric experiments since they potentially can answer such important questions as: whether or not the melting efficiency of the LBW process is superior to that obtainable with conventional GTAW and PAW welding processes This study was prompted by poor production yields on switching device due to cracking of the ceramic header after final closure welding with the CO{sub 2} LBW process. This calorimetric study was begun in hopes of determining if allowed variations in production process control variables were responsible for increases in heat input and the resulting thermal stresses. By measuring the net heat input to the workpiece with the calorimeter and by measuring the laser output energy and the weld fusion zone size it was possible to determine the magnitudes of both the energy transfer efficiency and the melting efficiency as well as observe their dependence on the process variables. 3 refs.

  18. Intraluminal tissue welding for anastomosis

    DOE Patents [OSTI]

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

    1998-10-27T23:59:59.000Z

    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.

  19. Intraluminal tissue welding for anastomosis

    DOE Patents [OSTI]

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

    1998-10-27T23:59:59.000Z

    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.

  20. Optical penetration sensor for pulsed laser welding

    DOE Patents [OSTI]

    Essien, Marcelino (Albuquerque, NM); Keicher, David M. (Albuquerque, NM); Schlienger, M. Eric (Albuquerque, NM); Jellison, James L. (Albuquerque, NM)

    2000-01-01T23:59:59.000Z

    An apparatus and method for determining the penetration of the weld pool created from pulsed laser welding and more particularly to an apparatus and method of utilizing an optical technique to monitor the weld vaporization plume velocity to determine the depth of penetration. A light source directs a beam through a vaporization plume above a weld pool, wherein the plume changes the intensity of the beam, allowing determination of the velocity of the plume. From the velocity of the plume, the depth of the weld is determined.

  1. Tungsten Transport in JET H-mode Plasmas in Hybrid Scenario, Experimental Observations and Modelling

    E-Print Network [OSTI]

    Tungsten Transport in JET H-mode Plasmas in Hybrid Scenario, Experimental Observations and Modelling

  2. Author's personal copy Tungsten geochemistry and implications for understanding the Earth's interior

    E-Print Network [OSTI]

    Mcdonough, William F.

    Author's personal copy Tungsten geochemistry and implications for understanding the Earth Keywords: tungsten uranium basalt core mantle concentration ratio The concentration of tungsten (W of tungsten (W) was sequestered into the core (Jagoutz et al., 1979; Sun, 1982; Newsom and Palme, 1984

  3. Failure Modes of Vacuum Plasma Spray Tungsten Coating Created on Carbon Fibre Composites under Thermal Loads

    E-Print Network [OSTI]

    Failure Modes of Vacuum Plasma Spray Tungsten Coating Created on Carbon Fibre Composites under Thermal Loads

  4. TUNGSTEN--2003 79.1 References that include a section mark () are found in the Internet

    E-Print Network [OSTI]

    Stockpile (NDS) and increases in stocks held by U.S. industry. No U.S. tungsten mine production was reported reported in 2001. Salient U.S. tungsten statistics and world tungsten concentrate production for 2003TUNGSTEN--2003 79.1 1 References that include a section mark (§) are found in the Internet

  5. Shimmed electron beam welding process

    DOE Patents [OSTI]

    Feng, Ganjiang (Clifton Park, NY); Nowak, Daniel Anthony (Alplaus, NY); Murphy, John Thomas (Niskayuna, NY)

    2002-01-01T23:59:59.000Z

    A modified electron beam welding process effects welding of joints between superalloy materials by inserting a weldable shim in the joint and heating the superalloy materials with an electron beam. The process insures a full penetration of joints with a consistent percentage of filler material and thereby improves fatigue life of the joint by three to four times as compared with the prior art. The process also allows variable shim thickness and joint fit-up gaps to provide increased flexibility for manufacturing when joining complex airfoil structures and the like.

  6. Crutcher introduces new automatic welding system

    SciTech Connect (OSTI)

    Not Available

    1982-04-01T23:59:59.000Z

    Designed for pipe over 16 in. but suitable for smaller diameters if modified slightly, a new automatic welding system uses the metal inert gas process to weld the root bead from the outside with a specially designed backup ring that adapts to a standard internal pipe clamp, making internal welding unnecessary. Individual welding machines travel on flexible tracks that are positioned by a track-locating device; two machines are required at each welding station. Particularly applicable to lay-barge operations, the system consists of (1) a pipe-facing machine, (2) a diesel-driven hydraulic power unit, (3) a carriage track, (4) an air-driven, air-operated, simplified pipe clamp, and (5) a welding bug assembly consisting of a carriage with drive unit, welding head, oscillator, and wire spool mount with drag-brake assembly.

  7. Weld penetration and defect control. Final report

    SciTech Connect (OSTI)

    Chin, B.A.

    1992-05-15T23:59:59.000Z

    Highly engineered designs increasingly require the use of improved materials and sophisticated manufacturing techniques. To obtain optimal performance from these engineered products, improved weld properties and joint reliability are a necessarily. This requirement for improved weld performance and reliability has led to the development of high-performance welding systems in which pre-programmed parameters are specified before any welding takes place. These automated systems however lack the ability to compensate for perturbations which arise during the welding process. Hence the need for systems which monitor and control the in-process status of the welding process. This report discusses work carried out on weld penetration indicators and the feasibility of using these indicators for on-line penetration control.

  8. Preparation and electrocatalytic activity of tungsten carbide and titania nanocomposite

    SciTech Connect (OSTI)

    Hu, Sujuan; Shi, Binbin; Yao, Guoxing [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)] [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China); Li, Guohua, E-mail: nanozjut@zjut.edu.cn [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)] [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China); Ma, Chunan [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)] [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)

    2011-10-15T23:59:59.000Z

    Graphical abstract: The electrocatalytic activity of tungsten carbide and titania nanocomposite is related to the structure, crystal phase and chemical components of the nanocomposite, and is also affected by the property of electrolyte. A synergistic effect exists between tungsten carbide and titania of the composite. Highlights: {yields} Electrocatalytic activity of tungsten carbide and titania nanocomposite with core-shell structure. {yields} Activity is related to the structure, crystal phase and chemical component of the nanocomposite. {yields} The property of electrolyte affects the electrocatalytic activity. {yields} A synergistic effect exists between tungsten carbide and titania of the composite. -- Abstract: Tungsten carbide and titania nanocomposite was prepared by combining a reduced-carbonized approach with a mechanochemical approach. The samples were characterized by X-ray diffraction, transmission electron microscope under scanning mode and X-ray energy dispersion spectrum. The results show that the crystal phases of the samples are composed of anatase, rutile, nonstoichiometry titanium oxide, monotungsten carbide, bitungsten carbide and nonstoichiometry tungsten carbide, and they can be controlled by adjusting the parameters of the reduced-carbonized approach; tungsten carbide particles decorate on the surface of titania support, the diameter of tungsten carbide particle is smaller than 20 nm and that of titania is around 100 nm; the chemical components of the samples are Ti, O, W and C. The electrocatalytic activity of the samples was measured by a cyclic voltammetry with three electrodes. The results indicate that the electrocatalytic activities of the samples are related to their crystal phases and the property of electrolyte in aqueous solution. A synergistic effect between titania and tungsten carbide is reported for the first time.

  9. Random Curves by Conformal Welding

    E-Print Network [OSTI]

    K. Astala; P. Jones; A. Kupiainen; E. Saksman

    2009-12-17T23:59:59.000Z

    We construct a conformally invariant random family of closed curves in the plane by welding of random homeomorphisms of the unit circle given in terms of the exponential of Gaussian Free Field. We conjecture that our curves are locally related to SLE$(\\kappa)$ for $\\kappa<4$.

  10. Random Curves by Conformal Welding

    E-Print Network [OSTI]

    Astala, K; Kupiainen, A; Saksman, E

    2009-01-01T23:59:59.000Z

    We construct a conformally invariant random family of closed curves in the plane by welding of random homeomorphisms of the unit circle given in terms of the exponential of Gaussian Free Field. We conjecture that our curves are locally related to SLE$(\\kappa)$ for $\\kappa<4$.

  11. Filters for cathodic arc plasmas

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA); Bilek, Marcela M. M. (Engadine, AU); Brown, Ian G. (Berkeley, CA)

    2002-01-01T23:59:59.000Z

    Cathodic arc plasmas are contaminated with macroparticles. A variety of magnetic plasma filters has been used with various success in removing the macroparticles from the plasma. An open-architecture, bent solenoid filter, with additional field coils at the filter entrance and exit, improves macroparticle filtering. In particular, a double-bent filter that is twisted out of plane forms a very compact and efficient filter. The coil turns further have a flat cross-section to promote macroparticle reflection out of the filter volume. An output conditioning system formed of an expander coil, a straightener coil, and a homogenizer, may be used with the magnetic filter for expanding the filtered plasma beam to cover a larger area of the target. A cathodic arc plasma deposition system using this filter can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  12. Effect of Welding Speed and Defocusing Distance on the Quality of Laser Welded Ti-6Al-4V

    E-Print Network [OSTI]

    Medraj, Mamoun

    Effect of Welding Speed and Defocusing Distance on the Quality of Laser Welded Ti-6Al-4V A:YAG laser, Laser welding, Ti-6Al-4V alloy Abstract In this study, the weldability of 5.1-mm thick Ti-6Al-4V at various welding speeds and defocusing distances. The joint quality was characterized in terms of weld

  13. Tungsten-doped thin film materials

    DOE Patents [OSTI]

    Xiang, Xiao-Dong; Chang, Hauyee; Gao, Chen; Takeuchi, Ichiro; Schultz, Peter G.

    2003-12-09T23:59:59.000Z

    A dielectric thin film material for high frequency use, including use as a capacitor, and having a low dielectric loss factor is provided, the film comprising a composition of tungsten-doped barium strontium titanate of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3, where X is between about 0.5 and about 1.0. Also provided is a method for making a dielectric thin film of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3 and doped with W, where X is between about 0.5 and about 1.0, a substrate is provided, TiO.sub.2, the W dopant, Ba, and optionally Sr are deposited on the substrate, and the substrate containing TiO.sub.2, the W dopant, Ba, and optionally Sr is heated to form a low loss dielectric thin film.

  14. Stability measurements of PPL atmospheric pressure arc

    SciTech Connect (OSTI)

    Roquemore, L.; Zweben, S.J. [Princeton Plasma Physics Lab., NJ (United States); Wurden, G.A. [Los Alamos National Lab., NM (United States)

    1997-12-31T23:59:59.000Z

    Experiments on the stability of atmospheric pressure arcs have been started at PPL to understand and improve the performance of arc furnaces used for processing applications in metallurgy and hazardous waste treatment. Previous studies have suggested that the violent instabilities in such arcs may be due to kink modes. A 30 kW, 500 Amp CW DC experimental arc furnace was constructed with a graphite cathode and a molten steel anode. The arc plasma is diagnosed with 4000 frames/sec digital camera, Hall probes, and voltage and current monitors. Under certain conditions, the arc exhibits an intermittent helical instability, with the helix rotating at {approx}600 Hz. The nature of the instability is investigated. A possible instability mechanism is the self-magnetic field of the arc, with saturation occurring due to inhomogeneous heating in a helical arc. The effect of external DC and AC magnetic fields on the instability is investigated. Additionally, arc deflection due to external transverse magnetic field is investigated. The deflection angle is found to be proportional to the applied field, and is in good agreement with a simple model of the {rvec J} x {rvec b} force on the arc jet.

  15. Atomistic computer simulation analysis of nanocrystalline nickel-tungsten alloys

    E-Print Network [OSTI]

    Engwall, Alison Michelle

    2009-01-01T23:59:59.000Z

    Nanocrystalline nickel-tungsten alloys are harder, stronger, more resistant to degradation, and safer to electrodeposit than chromium. Atomistic computer simulations have previously met with success in replicating the ...

  16. Microstructured tungsten thermophotovoltaic selective emitters c by Natalija (Zorana) Jovanovi?.

    E-Print Network [OSTI]

    Jovanovic, Natalija Zorana

    2008-01-01T23:59:59.000Z

    This research investigates the fabrication, modeling, characterization, and application of tungsten two-dimensional (2D) photonic crystal (PhC) structures as selective emitters and means of achieving higher efficiencies ...

  17. Alkyne metathesis by molybdenum and tungsten alkylidyne complexes

    E-Print Network [OSTI]

    Schrock, Richard Royce

    Alkyne metathesis by molybdenum and tungsten alkylidyne complexes is now ~45 years old. Progress in the practical aspects of alkyne metathesis reactions with well-defined complexes, as well as applications, in the last ...

  18. Tungsten carbide-cobalt by Three Dimensional Printing

    E-Print Network [OSTI]

    Kelley, Andrew, III

    1998-01-01T23:59:59.000Z

    Three Dimensional Printing is an additive manufacturing process for rapid prototyping ceramic and metallic parts [Sachs, et al, 1990]. Green (not sintered) tungsten carbide-cobalt parts must have a density greater than 50% ...

  19. Pressure Resistance Welding of High Temperature Metallic Materials

    SciTech Connect (OSTI)

    N. Jerred; L. Zirker; I. Charit; J. Cole; M. Frary; D. Butt; M. Meyer; K. L. Murty

    2010-10-01T23:59:59.000Z

    Pressure Resistance Welding (PRW) is a solid state joining process used for various high temperature metallic materials (Oxide dispersion strengthened alloys of MA957, MA754; martensitic alloy HT-9, tungsten etc.) for advanced nuclear reactor applications. A new PRW machine has been installed at the Center for Advanced Energy Studies (CAES) in Idaho Falls for conducting joining research for nuclear applications. The key emphasis has been on understanding processing-microstructure-property relationships. Initial studies have shown that sound joints can be made between dissimilar materials such as MA957 alloy cladding tubes and HT-9 end plugs, and MA754 and HT-9 coupons. Limited burst testing of MA957/HT-9 joints carried out at various pressures up to 400oC has shown encouraging results in that the joint regions do not develop any cracking. Similar joint strength observations have also been made by performing simple bend tests. Detailed microstructural studies using SEM/EBSD tools and fatigue crack growth studies of MA754/HT-9 joints are ongoing.

  20. ARC-ED Curriculum: The Application of Video Game Formats to Educational Software

    E-Print Network [OSTI]

    Chaffin, Jerry D.; Maxwell, Bill; Thompson, Barbara

    1982-01-01T23:59:59.000Z

    educational practices are examined in relation to the motivational features of arcade games. Also, guidelines for educational curriculum based on arcade game formats are proposed and the term Arc-Ed Curriculum is offered to describe such software. The content...

  1. Surface Coating of Tungsten Carbide by Electric Exploding of Contact

    SciTech Connect (OSTI)

    Grigoryev, Evgeny G. [General Physics Department, Moscow Engineering Physics Institute, Kashirskoe sh. 31, Moscow, 115409 (Russian Federation)

    2011-01-17T23:59:59.000Z

    Electric exploding of a tungsten carbide--cobalt material near-by high-speed steel surface forms on it a hardening coating. The essential structure properties of the formed coatings are determined by parameters of contact exploding electrode at the pulse current amplitude from above 106 A/cm2 and duration less than 10-4 s. The metallographic investigations of coating structures were done by microscope 'Neophot-24'. They have shown that the contact electric exploding caused the transfer of tungsten carbide and cobalt on the surface of high-speed steel. The breakdown of tungsten carbide--cobalt material took place during electrical exploding. The hardening layers of tungsten carbide and pure nanocrystalline tungsten have been formed upon the surface of high-speed steel as a result of electric exploding. Crystalline grains of tungsten have an almost spherical form and their characteristic size less than 400 nanometers. Micro hardness of the coating layers and high-speed steel structures was measured.

  2. Method and device for frictional welding

    DOE Patents [OSTI]

    Peacock, H.B.

    1992-10-13T23:59:59.000Z

    A method is described 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 canister 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. 5 figs.

  3. Method and device for frictional welding

    DOE Patents [OSTI]

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

    1992-01-01T23:59:59.000Z

    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.

  4. Passively damped vibration welding system and method

    DOE Patents [OSTI]

    Tan, Chin-An; Kang, Bongsu; Cai, Wayne W.; Wu, Tao

    2013-04-02T23:59:59.000Z

    A vibration welding system includes a controller, welding horn, an anvil, and a passive damping mechanism (PDM). The controller generates an input signal having a calibrated frequency. The horn vibrates in a desirable first direction at the calibrated frequency in response to the input signal to form a weld in a work piece. The PDM is positioned with respect to the system, and substantially damps or attenuates vibration in an undesirable second direction. A method includes connecting the PDM having calibrated properties and a natural frequency to an anvil of an ultrasonic welding system. Then, an input signal is generated using a weld controller. The method includes vibrating a welding horn in a desirable direction in response to the input signal, and passively damping vibration in an undesirable direction using the PDM.

  5. Method and device for frictional welding

    DOE Patents [OSTI]

    Peacock, H.B.

    1991-01-01T23:59:59.000Z

    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.

  6. Linkage of the ArcHydro Data Model with SWAT

    E-Print Network [OSTI]

    Linkage of the ArcHydro Data Model with SWAT Francisco Olivera, Ph.D., P.E. Milver Valenzuela Texas on a hub basis. Independent of the already connected models HUB #12;Arc Hydro Arc Hydro can be used as the hub for connecting hydrologic models. #12;Arc Hydro #12;What it is and what it is not ... Arc Hydro

  7. Development of a comprehensive weld process model

    SciTech Connect (OSTI)

    Radhakrishnan, B.; Zacharia, T.; Paul, A.

    1997-05-01T23:59:59.000Z

    This cooperative research and development agreement (CRADA) between Concurrent Technologies Corporation (CTC) and Lockheed Martin Energy Systems (LMES) combines CTC`s expertise in the welding area and that of LMES to develop computer models and simulation software for welding processes. This development is of significant impact to the industry, including materials producers and fabricators. The main thrust of the research effort was to develop a comprehensive welding simulation methodology. A substantial amount of work has been done by several researchers to numerically model several welding processes. The primary drawback of most of the existing models is the lack of sound linkages between the mechanistic aspects (e.g., heat transfer, fluid flow, and residual stress) and the metallurgical aspects (e.g., microstructure development and control). A comprehensive numerical model which can be used to elucidate the effect of welding parameters/conditions on the temperature distribution, weld pool shape and size, solidification behavior, and microstructure development, as well as stresses and distortion, does not exist. It was therefore imperative to develop a comprehensive model which would predict all of the above phenomena during welding. The CRADA built upon an already existing three-dimensional (3-D) welding simulation model which was developed by LMES which is capable of predicting weld pool shape and the temperature history in 3-d single-pass welds. However, the model does not account for multipass welds, microstructural evolution, distortion and residual stresses. Additionally, the model requires large resources of computing time, which limits its use for practical applications. To overcome this, CTC and LMES have developed through this CRADA the comprehensive welding simulation model described above.

  8. Metals purification by improved vacuum arc remelting

    DOE Patents [OSTI]

    Zanner, Frank J. (Sandia Park, NM); Williamson, Rodney L. (Albuquerque, NM); Smith, Mark F. (Albuquerque, NM)

    1994-12-13T23:59:59.000Z

    The invention relates to improved apparatuses and methods for remelting metal alloys in furnaces, particularly consumable electrode vacuum arc furnaces. Excited reactive gas is injected into a stationary furnace arc zone, thus accelerating the reduction reactions which purify the metal being melted. Additionally, a cooled condensation surface is disposed within the furnace to reduce the partial pressure of water in the furnace, which also fosters the reduction reactions which result in a purer produced ingot. Methods and means are provided for maintaining the stationary arc zone, thereby reducing the opportunity for contaminants evaporated from the arc zone to be reintroduced into the produced ingot.

  9. Chemical composition and RT[sub NDT] determinations for Midland weld WF-70

    SciTech Connect (OSTI)

    Nanstad, R.K.; McCabe, D.E.; Swain, R.L.; Miller, M.K. (Oak Ridge National Lab., TN (United States))

    1992-12-01T23:59:59.000Z

    The Heavy-Section Steal Irradiation Program Tenth Irradiation Series has the objective to investigate the affects of radiation on the fracture toughness of the low-upper-shelf submerged-arc welds (B W designation WF-70) in the reactor pressure vessel of the canceled Midland Unit 1 nuclear plant. This report discusses determination of variations in chemical composition And reference temperature (RT[sub NDT]) throughout the welds. Specimens were machined from different sections and through thickness locations in both the beltline and nozzle course welds. The nil-ductility transition temperatures ranged from [minus]40 to [minus]60[degrees]C ([minus]40 and [minus]76[degrees]F) while the RT[sub NDT]S, controlled by the Charpy behavior, varied from [minus]20 to 37[degrees]C ([minus]4 to 99[degrees]F). The upper-shelf energies varied from 77 to 108 J (57 to 80 ft-lb). The combined data revealed a mean 41-J (30-ft-lb) temperature of [minus]8[degrees]C (17[degrees]F) with a mean upper-shelf energy of 88 J (65 ft-lb). The copper contents range from 0.21 to 0.34 wt % in the beltline weld and from 0.37 to 0.46 wt % in the nozzle course weld. Atom probe field ion microscope analyses indicated substantial depletion of copper in the matrix but no evidence of copper clustering. Statistical analyses of the Charpy and chemical composition results as well as interpretation of the ASME procedures for RT[sub NDT] determination are discussed.

  10. Welding apparatus and methods for using ultrasonic sensing

    DOE Patents [OSTI]

    McJunkin, Timothy R.; Johnson, John A.; Larsen, Eric D.; Smartt, Herschel B.

    2006-08-22T23:59:59.000Z

    A welding apparatus using ultrasonic sensing is described and which includes a movable welder having a selectively adjustable welding head for forming a partially completed weld in a weld seam defined between adjoining metal substrates; an ultrasonic assembly borne by the moveable welder and which is operable to generate an ultrasonic signal which is directed toward the partially completed weld, and is further reflected from same; and a controller electrically coupled with the ultrasonic assembly and controllably coupled with the welding head, and wherein the controller receives information regarding the ultrasonic signal and in response to the information optimally positions the welding head relative to the weld seam.

  11. Promising Inspection Technique for Vehicle Welding Offers Efficient...

    Office of Environmental Management (EM)

    Promising Inspection Technique for Vehicle Welding Offers Efficient Alternative Promising Inspection Technique for Vehicle Welding Offers Efficient Alternative April 22, 2015 -...

  12. THE DEVELOPMENT OF MICROSTRUCTURE IN DUPLEX STAINLESS STEEL WELDS

    E-Print Network [OSTI]

    Cambridge, University of

    THE DEVELOPMENT OF MICROSTRUCTURE IN DUPLEX STAINLESS STEEL WELDS by Naseem Issa Abdallah Haddad;The Development of Microstructure in Duplex Stainless Steel Welds Abstract Duplex stainless steels

  13. Groundwater Modeling in ArcView: by integrating ArcView, MODFLOW and

    E-Print Network [OSTI]

    Sengupta, Raja

    Groundwater Modeling in ArcView: by integrating ArcView, MODFLOW and MODPATH Abstract Modeling. This paper addresses groundwater modeling which is one of the many entities in environmental modeling in ArcView 3.2a. The objective was to create an integrated system where a user could do groundwater

  14. Welding the AT-400A Containment Vessel

    SciTech Connect (OSTI)

    Brandon, E.

    1998-11-01T23:59:59.000Z

    Early in 1994, the Department of Energy assigned Sandia National Laboratories the responsibility for designing and providing the welding system for the girth weld for the AT-400A containment vessel. (The AT-400A container is employed for the shipment and long-term storage of the nuclear weapon pits being returned from the nation's nuclear arsenal.) Mason Hanger Corporation's Pantex Plant was chosen to be the production facility. The project was successfully completed by providing and implementing a turnkey welding system and qualified welding procedure at the Pantex Plant. The welding system was transferred to Pantex and a pilot lot of 20 AT-400A containers with W48 pits was welded in August 1997. This document is intended to bring together the AT-400A welding system and product (girth weld) requirements and the activities conducted to meet those requirements. This document alone is not a complete compilation of the welding development activities but is meant to be a summary to be used with the applicable references.

  15. Lienert named American Welding Society Fellow

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

    and industry with great distinction as an individual who contributed significantly to the knowledge, science, and application of welding," the society said in a statement. Research...

  16. Miniaturized cathodic arc plasma source

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA)

    2003-04-15T23:59:59.000Z

    A cathodic arc plasma source has an anode formed of a plurality of spaced baffles which extend beyond the active cathode surface of the cathode. With the open baffle structure of the anode, most macroparticles pass through the gaps between the baffles and reflect off the baffles out of the plasma stream that enters a filter. Thus the anode not only has an electrical function but serves as a prefilter. The cathode has a small diameter, e.g. a rod of about 1/4 inch (6.25 mm) diameter. Thus the plasma source output is well localized, even with cathode spot movement which is limited in area, so that it effectively couples into a miniaturized filter. With a small area cathode, the material eroded from the cathode needs to be replaced to maintain plasma production. Therefore, the source includes a cathode advancement or feed mechanism coupled to cathode rod. The cathode also requires a cooling mechanism. The movable cathode rod is housed in a cooled metal shield or tube which serves as both a current conductor, thus reducing ohmic heat produced in the cathode, and as the heat sink for heat generated at or near the cathode. Cooling of the cathode housing tube is done by contact with coolant at a place remote from the active cathode surface. The source is operated in pulsed mode at relatively high currents, about 1 kA. The high arc current can also be used to operate the magnetic filter. A cathodic arc plasma deposition system using this source can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  17. T-1018 UCLA Spacordion Tungsten Powder Calorimeter

    SciTech Connect (OSTI)

    Trentalange, Stephen; Tsai, Oleg; Igo, George; Huang, Huan; Pan, Yu Xi; Dunkelberger, Jay; Xu, Wen Qin; /UCLA; Soha, Aria; /Fermilab; Heppelmann, Steven; /Penn State U.; Gagliardi, Carl; /Texas A-M

    2011-11-16T23:59:59.000Z

    The present experiments at the BNL-RHIC facility are evolving towards physics goals which require the detection of medium energy electromagnetic particles (photons, electrons, neutral pions, eta mesons, etc.), especially at forward angles. New detectors will place increasing demands on energy resolution, hadron rejection and two-photon resolution and will require large area, high performance electromagnetic calorimeters in a variety of geometries. In the immediate future, either RHIC or JLAB will propose a facility upgrade (Electron-Ion Collider, or EIC) with physics goals such as electron-heavy ion collisions (or p-A collisions) with a wide range of calorimeter requirements. An R and D program based at Brookhaven National Laboratory has awarded the group funding of approximately $110,000 to develop new types of calorimeters for EIC experiments. The UCLA group is developing a method to manufacture very flexible and cost-effective, yet high quality calorimeters based on scintillating fibers and tungsten powder. The design and features of the calorimeter can be briefly stated as follows: an arbitrarily large number of small diameter fibers (< 0.5 mm) are assembled as a matrix and held rigidly in place by a set of precision screens inside an empty container. The container is then back-filled with tungsten powder, compacted on a vibrating table and infused with epoxy under vacuum. The container is then removed. The resulting sub-modules are extremely uniform and achieve roughly the density of pure Lead. The sub-modules are stacked together to achieve a final detector of the desired shape. There is no dead space between sub-modules and the fibers can be in an accordion geometry bent to prevent 'channeling' of the particles due to accidental alignment of their track with the module axis. This technology has the advantage of being modular and inexpensive to the point where the construction work may be divided among groups the size of typical university physics departments. This test run if a proof-of-principle and allows the experiment to improve the design and performance of the final detectors. The experimenters have constructed prototypes of three different designs in order to investigate the characteristics of practical devices such as uniformity, linearity, longitudinal and transverse shower shapes. The first design is an array of 4 x 4 modules intended as a prototype for a practical device to be installed within two years in the STAR experimental hall. The modules are a combination of a spaghetti calorimeter and an accordion (hence 'spacordion'). Each sub-module is 1.44 cm x 1.44 cm x 15 cm and constructed individually. The second design is a prototype of 4 sub-modules constructed in one step, using a different construction technique. The third design is a set of single sub-modules each intended to test variations of the tungsten powder/embedded fiber concept by enhancing the light output/density using liquid scintillator or heavy liquids.

  18. Welding shield for coupling heaters

    DOE Patents [OSTI]

    Menotti, James Louis (Dickinson, TX)

    2010-03-09T23:59:59.000Z

    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.

  19. Plasma arc melting of zirconium

    SciTech Connect (OSTI)

    Tubesing, P.K.; Korzekwa, D.R.; Dunn, P.S.

    1997-12-31T23:59:59.000Z

    Zirconium, like some other refractory metals, has an undesirable sensitivity to interstitials such as oxygen. Traditionally, zirconium is processed by electron beam melting to maintain minimum interstitial contamination. Electron beam melted zirconium, however, does not respond positively to mechanical processing due to its large grain size. The authors undertook a study to determine if plasma arc melting (PAM) technology could be utilized to maintain low interstitial concentrations and improve the response of zirconium to subsequent mechanical processing. The PAM process enabled them to control and maintain low interstitial levels of oxygen and carbon, produce a more favorable grain structure, and with supplementary off-gassing, improve the response to mechanical forming.

  20. Polymer Welding: Strength Through Entanglements

    E-Print Network [OSTI]

    Ting Ge; Flint Pierce; Dvora Perahia; Gary S. Grest; Mark O. Robbins

    2012-11-29T23:59:59.000Z

    Large-scale simulations of thermal welding of polymers are performed to investigate the rise of mechanical strength at the polymer-polymer interface with the welding time. The welding process is in the core of integrating polymeric elements into devices as well as in thermal induced healing of polymers; processes that require development of interfacial strength equal to that of the bulk. Our simulations show that the interfacial strength saturates at the bulk shear strength much before polymers diffuse by their radius of gyration. Along with the strength increase, the dominant failure mode changes from chain pullout at the interface to chain scission as in the bulk. Formation of sufficient entanglements across the interface, which we track using a Primitive Path Analysis is required to arrest catastrophic chain pullout at the interface. The bulk response is not fully recovered until the density of entanglements at the interface reaches the bulk value. Moreover, the increase of interfacial strength before saturation is proportional to the number of interfacial entanglements between chains from opposite sides.

  1. Impact of tool wear on joint strength in friction stir spot welding of DP 980 steel

    SciTech Connect (OSTI)

    Miles, Michael; Ridges, Chris; Hovanski, Yuri; Peterson, Jeremy; Santella, M. L.; Steel, Russel

    2011-09-14T23:59:59.000Z

    Friction stir spot welding has been shown to be a viable method of joining ultra high strength steel (UHSS), both in terms of joint strength and process cycle time. However, the cost of tooling must be reasonable in order for this method to be adopted as an industrial process. Recently a new tool alloy has been developed, using a blend of PCBN and tungsten rhenium (W-Re) in order to improve the toughness of the tool. Wear testing results are presented for two of these alloys: one with a composition of 60% PCBN and 40% W-Re, and one with 70% PCBN and 30% W-Re. The sheet material used for all wear testing was 1.4 mm DP 980. Lap shear testing was used to show the relationship between tool wear and joint strength. The Q70 tool provided the best combination of wear resistance and joint strength.

  2. Development of a Comprehensive Weld Process Model

    SciTech Connect (OSTI)

    Radhakrishnan, B.; Zacharia, T.

    1997-05-01T23:59:59.000Z

    This cooperative research and development agreement (CRADA) between Concurrent Technologies Corporation (CTC) and Lockheed Martin Energy Systems (LMES) combines CTC's expertise in the welding area and that of LMES to develop computer models and simulation software for welding processes. This development is of significant impact to the industry, including materials producers and fabricators. The main thrust of the research effort was to develop a comprehensive welding simulation methodology. A substantial amount of work has been done by several researchers to numerically model several welding processes. The primary drawback of most of the existing models is the lack of sound linkages between the mechanistic aspects (e.g., heat transfer, fluid flow, and residual stress) and the metallurgical aspects (e.g., microstructure development and control). A comprehensive numerical model which can be used to elucidate the effect of welding parameters/conditions on the temperature distribution, weld pool shape and size, solidification behavior, and microstructure development, as well as stresses and distortion, does not exist. It was therefore imperative to develop a comprehensive model which would predict all of the above phenomena during welding. The CRADA built upon an already existing three- dimensional (3-D) welding simulation model which was developed by LMES which is capable of predicting weld pool shape and the temperature history in 3-d single-pass welds. However, the model does not account for multipass welds, microstructural evolution, distortion and residual stresses. Additionally, the model requires large resources of computing time, which limits its use for practical applications. To overcome this, CTC and LMES have developed through this CRADA the comprehensive welding simulation model described above. The following technical tasks have been accomplished as part of the CRADA. 1. The LMES welding code has been ported to the Intel Paragon parallel computer at ORNL. The timing results illustrate the potential of the modified computer model for the analysis of large-scale welding simulations. 2. The kinetics of grain structure evolution in the weld heat affected zone (HAZ) has been simulated with reasonable accuracy by coupling an improved MC grain growth algorithm with a methodology for converting the MC parameters of grain size and time to real parameters. The simulations effectively captured the thermal pinning phenomenon that has been reported in the weld HAZ. 3. A cellular automaton (CA) code has been developed to simulate the solidification microstructure in the weld fusion zone. The simulations effectively captured the epitaxial growth of the HAZ grains, the grain selection mechanism, and the formation of typical grain structures observed in the weld t%sion zone. 4. The point heat source used in the LMES welding code has ben replaced with a distributed heat source to better capture the thermal characteristics and energy distributions in a commercial welding heat source. 5. Coupled thermal-mechanical and metallurgical models have been developed to accurately predict the weld residual stresses, and 6. Attempts have been made to integrate the newly developed computational capabilities into a comprehensive weld design tool.

  3. Multi-mode ultrasonic welding control and optimization

    DOE Patents [OSTI]

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

    2013-05-28T23:59:59.000Z

    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.

  4. SmartWeld working session for the GTS4

    SciTech Connect (OSTI)

    Kleban, S. [Sandia National Labs., Albuquerque, NM (United States); Hicken, K.; Ng, R. [Sandia National Labs., Livermore, CA (United States); Fricke, B. [Allied Signal Kansas City Division, MO (United States)

    1997-08-01T23:59:59.000Z

    Results from SmartWeld`s first working session involving in-progress designs is presented. The Welding Advisor component of SmartWeld was thoroughly exercised, evaluated all eleven welds of the selected part. The Welding Advisor is an expert system implemented with object-oriented techniques for knowledge representation. With two welding engineers in attendance, the recommendations of the Welding Advisor were thoroughly examined and critiqued for accuracy and for areas of improvement throughout the working session. The Weld Schedule Database component of SmartWeld was also exercised. It is a historical archive of proven, successful weld schedules that can be intelligently searched using the current context of SmartWeld`s problem solving state. On all eleven welds, the experts agreed that Welding Advisor recommended the most risk free options. As a result of the Advisor`s recommendation, six welds agreed completely with the experts, two welds had their joint geometry modified for production, and three welds were not modified but extra care was exercised during welding. 25 figs., 3 tabs.

  5. Purification of tantalum by plasma arc melting

    DOE Patents [OSTI]

    Dunn, Paul S. (Santa Fe, NM); Korzekwa, Deniece R. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    Purification of tantalum by plasma arc melting. The level of oxygen and carbon impurities in tantalum was reduced by plasma arc melting the tantalum using a flowing plasma gas generated from a gas mixture of helium and hydrogen. The flowing plasma gases of the present invention were found to be superior to other known flowing plasma gases used for this purpose.

  6. Low-temperature chemical vapor deposition of tungsten from tungsten hexacarbonyl

    SciTech Connect (OSTI)

    Vogt, G.J.

    1982-04-01T23:59:59.000Z

    Chemical vapor deposition (CVD) of tungsten from W(CO)/sub 6/ has been investigated below 670 K as an alternate process to WF/sub 6/ CVD for coating glass microspheres. The major advantages of W(CO)/sub 6/ CVD are the elimination of the HF damage to the glass microspheres and potentially a lower deposition temperature for coating DT-filled microspheres. W(CO)/sub 6/ CVD can be utilized, in principle, to coat the microspheres with 1 to 5 ..mu..m of tungsten or to flash coat the microspheres for further coating by WF/sub 6/ CVD. Test coatings were deposited in a fluidized-bed reactor with a hydrogen carrier gas. The coatings were found to contain nearly equal portions of carbon and oxygen, ranging from 16 to 25 at.% for each element. The high carbon and oxygen concentrations are believed to result principally from the physical entrapment of chemisorbed CO molecules at the surface of the growing deposit. The general quality and adhesion of the W(CO)/sub 6/-derived coatings are unsatisfactory at this time for ICF applications.

  7. Nitrogen Control in Electric Arc Furnace Steelmaking by Direct...

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

    Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines Injection Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines...

  8. antilles island arc: Topics by E-print Network

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

    The morphology of the underthrust oceanic crust controls the mag matic activity of the island arc, and particularly the development, in space and time, of "arc compartments." Denis...

  9. Type B Accident Investigation of the Arc Flash at Brookhaven...

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

    Arc Flash at Brookhaven National Laboratory, April 14, 2006 Type B Accident Investigation of the Arc Flash at Brookhaven National Laboratory, April 14, 2006 February 10, 2006 An...

  10. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, R.S.

    1987-11-17T23:59:59.000Z

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile. 2 figs.

  11. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, Ronald S. (Livermore, CA)

    1987-01-01T23:59:59.000Z

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

  12. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, R.S.

    1985-08-05T23:59:59.000Z

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

  13. Effect of Scratches on Pinch Welds

    SciTech Connect (OSTI)

    Korinko, P

    2005-10-11T23:59:59.000Z

    Fill stems for tritium reservoirs have stringent scratch requirements such that any indications that appear to have depth are cause for rework or rejection. A scoping study was undertaken to evaluate the effect of scratches approximately 0.0015 to 0.002 inch deep on the fitness for service and bond quality. The stems were characterized using borescope before and after welding. The four stems were welded with near optimal weld parameters, proof tested, and examined metallographically. The stems were radiographed, proof tested, and examined metallographically. The scratches did not adversely affect (1) the weld integrity based on radiography, (2) the ability to withstand the proof pressure, and (3) the weld quality based on metallographic cross-sections. Based on these limited results at a nominal weld current, the weld process is very robust. It may be able to recover from manufacturing defects and inspection anomalies worse than those expected for typical fill stem manufacturing processes; additional testing specific to each application over a range of weld heats is needed to verify applicability of these results.

  14. Seal welded cast iron nuclear waste container

    DOE Patents [OSTI]

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

    1987-01-01T23:59:59.000Z

    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.

  15. Thermochemical Analysis of Hydrogen Absorption in Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    '' .' j I ~l Thermochemical Analysis of Hydrogen Absorption in Welding A new model that addresses the shortcomings of Sievert's law for predicting hydrogen absorption is proposed ABSTRACT. A systematic review of diatomic hydrogen) to calcu· late the hydrogen absorption reaction temperature in the weld pool is invalid

  16. Manual tube-to-tubesheet welding torch

    DOE Patents [OSTI]

    Kiefer, Joseph H. (Tampa, FL); Smith, Danny J. (Tampa, FL)

    1982-01-01T23:59:59.000Z

    A welding torch made of a high temperature plastic which fits over a tube intermediate the ends thereof for welding the juncture between the tube and the back side of a tube plate and has a ballooned end in which an electrode, filler wire guide, fiber optic bundle, and blanketing gas duct are disposed.

  17. Design of Welding Alloys Creep and Toughness

    E-Print Network [OSTI]

    Marimuthu, Murugananth

    The subject of welding is challenging because of its complexity and because its applications are in the majority of cases, safety critical. The work presented in this thesis deals with both these aspects from the point of view of welding alloys...

  18. PHYSICAL REVIEW B 84, 092102 (2011) Melting temperature of tungsten from two ab initio approaches

    E-Print Network [OSTI]

    Alfè, Dario

    2011-01-01T23:59:59.000Z

    PHYSICAL REVIEW B 84, 092102 (2011) Melting temperature of tungsten from two ab initio approaches L the melting temperature of tungsten by two ab initio approaches. The first approach can be divided into two

  19. Structure-property Relationships in Pure and Doped Epitaxial Tungsten Trioxide Thin Films

    E-Print Network [OSTI]

    Structure-property Relationships in Pure and Doped Epitaxial Tungsten Trioxide Thin Films Principal-property relationships of well- defined epitaxial tungsten trioxide (WO3) films with and without dopants, and thereby

  20. Olefin Metathesis Reactions Initiated by d2 Molybdenum or Tungsten Complexes

    E-Print Network [OSTI]

    Müller, Peter

    Olefin Metathesis Reactions Initiated by d2 Molybdenum or Tungsten Complexes Richard R. Schrock species, behave as olefin metathesis catalysts. Recently we reported tungsten complexes that contain a Wd

  1. Room-Temperature Z-Selective Homocoupling of alpha-Olefins by Tungsten Catalysts

    E-Print Network [OSTI]

    Marinescu, Smaranda C.

    3,5-Dimethylphenylimido complexes of tungsten can be prepared using procedures analogous to those employed for other tungsten catalysts, as can bispyrrolide species and MonoAryloxide-Pyrrolide (MAP) species. Homocouplings ...

  2. Automated Spot Weld Inspection using Infrared Thermography

    SciTech Connect (OSTI)

    Chen, Jian [ORNL] [ORNL; Zhang, Wei [ORNL] [ORNL; Yu, Zhenzhen [ORNL] [ORNL; Feng, Zhili [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    An automated non-contact and non-destructive resistance spot weld inspection system based on infrared (IR) thermography was developed for post-weld applications. During inspection, a weld coupon was heated up by an auxiliary induction heating device from one side of the weld, while the resulting thermal waves on the other side were observed by an IR camera. The IR images were analyzed to extract a thermal signature based on normalized heating time, which was then quantitatively correlated to the spot weld nugget size. The use of normalized instead of absolute IR intensity was found to be useful in minimizing the sensitivity to the unknown surface conditions and environment interference. Application of the IR-based inspection system to different advanced high strength steels, thickness gauges and coatings were discussed.

  3. Subaqueous Explosive Eruption and Welding of Pyroclastic Deposits

    E-Print Network [OSTI]

    Busby, Cathy

    Subaqueous Explosive Eruption and Welding of Pyroclastic Deposits Peter Kokelaar and Cathy Busby fabrics indicative of welding of glass shards and pumice at temperatures >500"C. The occurrence emplacement temperature in pyroclas- tic deposits is welding. Welding is hot-state viscous deformation

  4. Optical Inspection of Welding Seams Fabian Timm1,2

    E-Print Network [OSTI]

    Optical Inspection of Welding Seams Fabian Timm1,2 , Thomas Martinetz1 , and Erhardt Barth1,2 1 present a framework for automatic inspection of welding seams based on specular reflections. To this end by using welding techniques. Soldering and welding techniques are common in diverse areas such as printed

  5. Theoretical analysis of ARC constriction

    SciTech Connect (OSTI)

    Stoenescu, M.L.; Brooks, A.W.; Smith, T.M.

    1980-12-01T23:59:59.000Z

    The physics of the thermionic converter is governed by strong electrode-plasma interactions (emissions surface scattering, charge exchange) and weak interactions (diffusion, radiation) at the maximum interelectrode plasma radius. The physical processes are thus mostly convective in thin sheaths in front of the electrodes and mostly diffusive and radiative in the plasma bulk. The physical boundaries are open boundaries to particle transfer (electrons emitted or absorbed by the electrodes, all particles diffusing through some maximum plasma radius) and to convective, conductive and radiative heat transfer. In a first approximation the thermionic converter may be described by a one-dimensional classical transport theory. The two-dimensional effects may be significant as a result of the sheath sensitivity to radial plasma variations and of the strong sheath-plasma coupling. The current-voltage characteristic of the converter is thus the result of an integrated current density over the collector area for which the boundary conditions at each r determine the regime (ignited/unignited) of the local current density. A current redistribution strongly weighted at small radii (arc constriction) limits the converter performance and opens questions on constriction reduction possibilities. The questions addressed are the followng: (1) what are the main contributors to the loss of current at high voltage in the thermionic converter; and (2) is arc constriction observable theoretically and what are the conditions of its occurrence. The resulting theoretical problem is formulated and results are given. The converter electrical current is estimated directly from the electron and ion particle fluxes based on the spatial distribution of the electron/ion density n, temperatures T/sub e/, T/sub i/, electrical voltage V and on the knowledge of the transport coefficients. (WHK)

  6. A history of tungsten- and molybdenum-base alloys

    SciTech Connect (OSTI)

    Heestand, R.L.

    1993-01-01T23:59:59.000Z

    The development of tungsten and molybdenum alloys was initiated in the early 1900s in search of a better electric lamp filament with tantalum, tungsten, rhenium, and osmium being the prime candidates. The efforts required for accomplishment of the task led to refining oxides to high purity, reduction of the oxides to metal powders, forming green product forms by extrusion or pressing, and finally sintering by electric furnace and self-heating by direct current almost to the melting point. The technology required for producing lamp filaments led to the development of the powder metallurgy field and early research on high-melting-temperature metals. During the period 1909 through 1959, most of the tungsten-molybdenum, high-melting-temperature element alloys were developed and produced in almost any product form required.

  7. A history of tungsten- and molybdenum-base alloys

    SciTech Connect (OSTI)

    Heestand, R.L.

    1993-05-01T23:59:59.000Z

    The development of tungsten and molybdenum alloys was initiated in the early 1900s in search of a better electric lamp filament with tantalum, tungsten, rhenium, and osmium being the prime candidates. The efforts required for accomplishment of the task led to refining oxides to high purity, reduction of the oxides to metal powders, forming green product forms by extrusion or pressing, and finally sintering by electric furnace and self-heating by direct current almost to the melting point. The technology required for producing lamp filaments led to the development of the powder metallurgy field and early research on high-melting-temperature metals. During the period 1909 through 1959, most of the tungsten-molybdenum, high-melting-temperature element alloys were developed and produced in almost any product form required.

  8. Mechanism of vacancy formation induced by hydrogen in tungsten

    SciTech Connect (OSTI)

    Liu, Yi-Nan [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China) [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China); Association EURATOM-TEKES, University of Helsinki, Helsinki, PO Box 64, 00560 (Finland); Ahlgren, T.; Bukonte, L.; Nordlund, K. [Association EURATOM-TEKES, University of Helsinki, Helsinki, PO Box 64, 00560 (Finland)] [Association EURATOM-TEKES, University of Helsinki, Helsinki, PO Box 64, 00560 (Finland); Shu, Xiaolin; Yu, Yi; Lu, Guang-Hong, E-mail: LGH@buaa.edu.cn [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China)] [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China); Li, Xiao-Chun [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China)] [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China)

    2013-12-15T23:59:59.000Z

    We report a hydrogen induced vacancy formation mechanism in tungsten based on classical molecular dynamics simulations. We demonstrate the vacancy formation in tungsten due to the presence of hydrogen associated directly with a stable hexagonal self-interstitial cluster as well as a linear crowdion. The stability of different self-interstitial structures has been further studied and it is particularly shown that hydrogen plays a crucial role in determining the configuration of SIAs, in which the hexagonal cluster structure is preferred. Energetic analysis has been carried out to prove that the formation of SIA clusters facilitates the formation of vacancies. Such a mechanism contributes to the understanding of the early stage of the hydrogen blistering in tungsten under a fusion reactor environment.

  9. Ductile tungsten-nickel alloy and method for making same

    DOE Patents [OSTI]

    Snyder, Jr., William B. (Knoxville, TN)

    1976-01-01T23:59:59.000Z

    The present invention is directed to a ductile, high-density tungsten-nickel alloy which possesses a tensile strength in the range of 100,000 to 140,000 psi and a tensile elongation of 3.1 to 16.5 percent in 1 inch at 25.degree.C. This alloy is prepared by the steps of liquid phase sintering a mixture of tungsten-0.5 to 10.0 weight percent nickel, heat treating the alloy at a temperature above the ordering temperature of approximately 970.degree.C. to stabilize the matrix phase, and thereafter rapidly quenching the alloy in a suitable liquid to maintain the matrix phase in a metastable, face-centered cubic, solid- solution of tungsten in nickel.

  10. Virtual Welded - Joint Design Integrating Advanced Materials and Processing Technology

    SciTech Connect (OSTI)

    Yang, Zhishang; Ludewig, Howard W.; Babu, S. Suresh

    2005-06-30T23:59:59.000Z

    Virtual Welede-Joint Design, a systematic modeling approach, has been developed in this project to predict the relationship of welding process, microstructure, properties, residual stress, and the ultimate weld fatique strength. This systematic modeling approach was applied in the welding of high strength steel. A special welding wire was developed in this project to introduce compressive residual stress at weld toe. The results from both modeling and experiments demonstrated that more than 10x fatique life improvement can be acheived in high strength steel welds by the combination of compressive residual stress from the special welding wire and the desired weld bead shape from a unique welding process. The results indicate a technology breakthrough in the design of lightweight and high fatique performance welded structures using high strength steels.

  11. Tungsten as first wall material in the main chamber of ASDEX Upgrade

    E-Print Network [OSTI]

    Tungsten as first wall material in the main chamber of ASDEX Upgrade V. Rohde, R. Neu, A. Geier, R material is tungsten, which has a high melting point, low erosion rate in cold scrape off layer plasma, where the present ITER-FEAT design uses tungsten. No negative influence on the plasma performance, even

  12. DOI: 10.1002/adsc.201100200 Preparation of Tungsten-Based Olefin Metathesis Catalysts

    E-Print Network [OSTI]

    Müller, Peter

    DOI: 10.1002/adsc.201100200 Preparation of Tungsten-Based Olefin Metathesis Catalysts Supported://dx.doi.org/10.1002/adcs.201100200. Abstract: A new tungsten alkylidene complex, WACHTUNGTRENNUNG catalysts; tungsten Introduction In the last dozen years various "well-defined" Mo/W[1] or Ru[2] olefin

  13. ORIGINAL PAPER Why is the molybdenum-substituted tungsten-dependent

    E-Print Network [OSTI]

    Liao, Rongzhen

    ORIGINAL PAPER Why is the molybdenum-substituted tungsten-dependent formaldehyde ferredoxin oxidoreductase is a tungsten-dependent enzyme that catalyzes the oxidative degradation of formaldehyde to formic acid. The moly- bdenum ion can be incorporated into the active site to displace the tungsten ion

  14. Syntheses of Tungsten tert-Butylimido and Adamantylimido Alkylidene Complexes Employing Pyridinium Chloride As the Acid

    E-Print Network [OSTI]

    Müller, Peter

    Syntheses of Tungsten tert-Butylimido and Adamantylimido Alkylidene Complexes Employing Pyridinium Supporting Information ABSTRACT: Routes to new tungsten alkylidene complexes that contain tert and tungsten, especially aryls that are mono- or disubstituted in the ortho position(s).2 However, it has

  15. Single-Crystal Tungsten Oxide Nanosheets: Photochemical Water Oxidation in the Quantum Confinement Regime

    E-Print Network [OSTI]

    Osterloh, Frank

    Single-Crystal Tungsten Oxide Nanosheets: Photochemical Water Oxidation in the Quantum Confinement, catalysis, WO3, tungsten oxide, nanosheet, nanocrystal, quantum confinement, solar energy conversion INTRODUCTION Tungsten trioxide crystallizes in the ReO3 structure type and is an n-type semiconductor with a 2

  16. Synthesis and Reactions of Tungsten Alkylidene Complexes That Contain the 2,6-Dichlorophenylimido Ligand

    E-Print Network [OSTI]

    Müller, Peter

    Synthesis and Reactions of Tungsten Alkylidene Complexes That Contain the 2,6-Dichlorophenylimido Institute of Technology, Cambridge, Massachusetts 02139 ReceiVed October 30, 2006 Tungsten alkylidene alkylidene bisalkoxide complexes of molybdenum or tungsten of the type M(NR)(CHR)(OR)2 are now established

  17. Imido Alkylidene Bispyrrolyl Complexes of Tungsten Thorsten Kreickmann, Stefan Arndt, Richard R. Schrock,* and Peter Muller

    E-Print Network [OSTI]

    Müller, Peter

    Imido Alkylidene Bispyrrolyl Complexes of Tungsten Thorsten Kreickmann, Stefan Arndt, Richard R, Massachusetts 02139 ReceiVed July 16, 2007 We have prepared tungsten bispyrrolyl (Pyr) or bis-2 this type of chemistry to tungsten. In this paper we report W(NR)(CHCMe2R)(pyrrolyl)2 complexes where R is 2

  18. Nanostructured tungsten carbide catalysts for polymer electrolyte fuel cells X. G. Yanga

    E-Print Network [OSTI]

    Nanostructured tungsten carbide catalysts for polymer electrolyte fuel cells X. G. Yanga and C. Y/air polymer electrolyte fuel cell using nanoscale tungsten carbide as the anode catalyst and carbon supported, thereby creating a fundamental technology to reduce the cost of future fuel cell engines. The tungsten

  19. Radial x-ray diffraction of tungsten tetraboride to 86 GPa under nonhydrostatic compression

    E-Print Network [OSTI]

    Lin, Jung-Fu "Afu"

    Radial x-ray diffraction of tungsten tetraboride to 86 GPa under nonhydrostatic compression Lun December 2012; published online 16 January 2013) Investigations of the equation of state of tungsten moduli and hardness exceed- ing or closing that of diamond. Tungsten tetraboride (WB4) is a candidate

  20. Z-Selective Olefin Metathesis Reactions Promoted by Tungsten Oxo Alkylidene Complexes

    E-Print Network [OSTI]

    Müller, Peter

    Z-Selective Olefin Metathesis Reactions Promoted by Tungsten Oxo Alkylidene Complexes Dmitry V). Early in the development of olefin metathesis catalysts that contain tungsten, it was shown that metathetically more active and reproducible systems were produced when tungsten oxo complexes were deliberately

  1. Compressibility and strength of nanocrystalline tungsten boride under compression to 60GPa

    E-Print Network [OSTI]

    Duffy, Thomas S.

    Compressibility and strength of nanocrystalline tungsten boride under compression to 60GPa Haini://jap.aip.org/about/rights_and_permissions #12;Compressibility and strength of nanocrystalline tungsten boride under compression to 60 GPa Haini of nanocrystalline tungsten boride (WB) were investigated using radial x-ray diffraction (RXRD) in a diamond

  2. Synthesis of Tungsten Imido Alkylidene Complexes that Contain an Electron-Withdrawing Imido Ligand

    E-Print Network [OSTI]

    Müller, Peter

    Synthesis of Tungsten Imido Alkylidene Complexes that Contain an Electron-Withdrawing Imido Ligand 02467, United States *S Supporting Information ABSTRACT: Tungsten NArR alkylidene complexes have been is the nature of Z. Perhaps the most dramatic variations are those in which M is tungsten and Z is an oxo ligand

  3. Mechanism of tungsten-dependent acetylene hydratase from quantum chemical calculations

    E-Print Network [OSTI]

    Liao, Rongzhen

    Mechanism of tungsten-dependent acetylene hydratase from quantum chemical calculations Rong hydratase is a tungsten-dependent enzyme that cata- lyzes the nonredox hydration of acetylene metalloenzyme cluster approach Tungsten is the heaviest metal in biology and plays prominent roles in carbon

  4. Real-time growth rate metrology for a tungsten chemical vapor deposition process by acoustic sensing

    E-Print Network [OSTI]

    Rubloff, Gary W.

    to a production-scale tungsten chemical vapor deposition cluster tool for in situ process sensing. Process gasesReal-time growth rate metrology for a tungsten chemical vapor deposition process by acoustic to achieve run-to-run process control of the deposited tungsten film thickness. © 2001 American Vacuum

  5. The Corrosion of Tungsten During Irradiation in an 800 MeV Proton Beam

    E-Print Network [OSTI]

    such technology is Accelerator Production of Tritium (APT). In APT a tungsten target is bombarded by a high energyThe Corrosion of Tungsten During Irradiation in an 800 MeV Proton Beam R. Scott Lillard, Darryl P of solid neutron spallation targets such as tungsten (W), and target cladding or structural materials

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Influence of welding passes on grain orientation - the example of a multi-pass V-weld. Jing YE;Abstract The accurate modelling of grain orientations in a weld is important, when accurate ultrasonic test predictions of a welded assembly are needed. To achieve this objective, Electricité de France (EDF

  8. Wear testing of friction stir spot welding tools for joining of DP 980 Steel

    SciTech Connect (OSTI)

    Ridges, Chris; Miles, Michael; Hovanski, Yuri; Peterson, Jeremy; Steel, Russell

    2011-06-06T23:59:59.000Z

    Friction stir spot welding has been shown to be a viable method of joining ultra high strength steel (UHSS), both in terms of joint strength and process cycle time. However, the cost of tooling must be reasonable in order for this method to be adopted as an industrial process. Several tooling materials have been evaluated in prior studies, including silicon nitride and polycrystalline cubic boron nitride (PCBN). Recently a new tool alloy has been developed, where a blend of PCBN and tungsten rhenium (W-Re) was used in order to improve the toughness of the tool. Wear testing results are presented for two of these alloys: one with a composition of 60% PCBN and 40% W-Re (designated as Q60), and one with 70% PCBN and 30% W-Re (designated at Q70). The sheet material used for all wear testing was DP 980. Tool profiles were measured periodically during the testing process in order to show the progression of wear as a function of the number of spots produced. Lap shear testing was done each time a tool profile was taken in order to show the relationship between tool wear and joint strength. For the welding parameters chosen for this study the Q70 tool provided the best combination of wear resistance and joint strength.

  9. Joining aluminum to titanium alloy by friction stir lap welding with cutting pin

    SciTech Connect (OSTI)

    Wei, Yanni [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072 (China) [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072 (China); Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi'an 710072 (China); Li, Jinglong, E-mail: lijinglg@nwpu.edu.cn [Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi'an 710072 (China)] [Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi'an 710072 (China); Xiong, Jiangtao [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072 (China) [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072 (China); Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi'an 710072 (China); Huang, Fu; Zhang, Fusheng; Raza, Syed Hamid [Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi'an 710072 (China)] [Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi'an 710072 (China)

    2012-09-15T23:59:59.000Z

    Aluminum 1060 and titanium alloy Ti-6Al-4V plates were lap joined by friction stir welding. A cutting pin of rotary burr made of tungsten carbide was employed. The microstructures of the joining interface were observed by scanning electron microscopy. Joint strength was evaluated by a tensile shear test. During the welding process, the surface layer of the titanium plate was cut off by the pin, and intensively mixed with aluminum situated on the titanium plate. The microstructures analysis showed that a visible swirl-like mixed region existed at the interface. In this region, the Al metal, Ti metal and the mixed layer of them were all presented. The ultimate tensile shear strength of joint reached 100% of 1060Al that underwent thermal cycle provided by the shoulder. - Highlights: Black-Right-Pointing-Pointer FSW with cutting pin was successfully employed to form Al/Ti lap joint. Black-Right-Pointing-Pointer Swirl-like structures formed due to mechanical mixing were found at the interface. Black-Right-Pointing-Pointer High-strength joints fractured at Al suffered thermal cycle were produced.

  10. An Application of Augmented Reality (AR) in the Teaching of an Arc Welding Robot

    E-Print Network [OSTI]

    Chong, J. W. S.

    Augmented Reality (AR) is an emerging technology that utilizes computer vision methods to overlay virtual objects onto the real world scene so as to make them appear to co-exist with the real objects. Its main objective ...

  11. Material Mixing of Tungsten with Carbon and Helium

    SciTech Connect (OSTI)

    Ueda, Y.; Lee, H. T. [Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871 (Japan)

    2010-05-20T23:59:59.000Z

    In ITER, graphite and tungsten are used for divertor materials and are mixed through erosion, transport, and redeposition. Helium, a fusion reactant, is an intrinsic element in fusion plasmas that impinges on the metallic wall materials to form He bubbles. W-C mixed layers and He bubble layers greatly affect tritium retention. In this paper, impacts of W-C material mixing on erosion and hydrogen isotope retention are reviewed. Then, recent results on carbon deposition on tungsten in TEXTOR tokamak and helium effects on blistering and retention are discussed.

  12. Production And Characterization Of Tungsten-Based Positron Moderators

    SciTech Connect (OSTI)

    Lucio, O. G. de; Morales, J. G.; Cruz-Manjarrez, H. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364 01000, Mexico DF (Mexico)

    2011-06-01T23:59:59.000Z

    Experiments of interest in Atomic Physics require production of well-defined low-energy positron beams through a moderation process of high-energy positrons, which can be produced by either the use of a radioactive source or by accelerator based pair production process. Tungsten is one of the most commonly used moderator materials because of its reasonable efficiency, high work function and relatively low cost. In this work we present different methods to produce tungsten-based candidate moderators in a variety of shapes. We also present results from characterizing these candidate moderators by ion beam analysis and microscopy techniques.

  13. Effects of sequential tungsten and helium ion implantation on nano-indentation hardness of tungsten

    SciTech Connect (OSTI)

    Armstrong, D. E. J.; Edmondson, P. D.; Roberts, S. G. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)] [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)

    2013-06-24T23:59:59.000Z

    To simulate neutron and helium damage in a fusion reactor first wall sequential self-ion implantation up to 13 dpa followed by helium-ion implantation up to 3000 appm was performed to produce damaged layers of {approx}2 {mu}m depth in pure tungsten. The hardness of these layers was measured using nanoindentation and was studied using transmission electron microscopy. Substantial hardness increases were seen in helium implanted regions, with smaller hardness increases in regions which had already been self-ion implanted, thus, containing pre-existing dislocation loops. This suggests that, for the same helium content, helium trapped in distributed vacancies gives stronger hardening than helium trapped in vacancies condensed into dislocation loops.

  14. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2006,

    E-Print Network [OSTI]

    178 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2006, approximately. Import Sources (2002-05): Tungsten contained in ores and concentrates, intermediate and primary products

  15. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2003,

    E-Print Network [OSTI]

    180 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2003, approximately and concentrates, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 49

  16. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2005,

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2005, approximately. Import Sources (2001-04): Tungsten contained in ores and concentrates, intermediate and primary products

  17. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded U.S. production of tungsten concentrates was in 1994. In 2001,

    E-Print Network [OSTI]

    180 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded U.S. production of tungsten concentrates was in 1994. In 2001, approximately, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 41%; Russia, 21

  18. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2002,

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2002, approximately, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 48%; Russia, 16

  19. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2004,

    E-Print Network [OSTI]

    180 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2004, approximately (2000-03): Tungsten content of ores and concentrates, intermediate and primary products, wrought

  20. Scan welding: Thermomechanical model and experimental validation

    SciTech Connect (OSTI)

    Fourligkas, N.; Doumanidis, C.C. [Tufts Univ., Medford, MA (United States)

    1996-12-31T23:59:59.000Z

    This article presents a comparative thermomechanical analysis of classical versus the new scan welding methods, that have been recently developed to achieve simultaneous control of multiple weld quality features. Unlike conventional welding with a concentrated heat source in sequential motion, the scan welding torch reciprocates rapidly on dynamic trajectories, and its power is modulated in-process, to provide a regulated heat input distribution on the entire weld surface. The new process was modeled by a real-time analytical, lumped model, consisting of a composite heat source description, double-cell circulation in the weld puddle, dynamic solid conduction and estimation of the mechanical strength of the joint. The process is computationally and experimentally shown to generate a smooth and uniform temperature field, and to deposit the full length of the weld bead simultaneously at a controlled solidification rate. The observed interlacing of grains on the bead interface and the regulated material microstructure yield improved tensile joint strength. The model can be used for design of a closed-loop thermal controller, using temperature feedback from an infrared pyrometer and model-referenced parameter identification.

  1. On the mechanism of operation of a cathode spot cell in a vacuum arc

    SciTech Connect (OSTI)

    Mesyats, G. A.; Petrov, A. A. [P. N. Lebedev Physical Institute, RAS, 53 Leninsky Ave., Moscow 119991 (Russian Federation); Bochkarev, M. B. [Institute of Electrophysics, UB, RAS, 106 Amundsen St., Ekaterinburg 620016 (Russian Federation); Barengolts, S. A., E-mail: sb@nsc.gpi.ru [A. M. Prokhorov General Physics Institute, RAS, 38 Vavilov St., Moscow 119991 (Russian Federation)

    2014-05-05T23:59:59.000Z

    The erosive structures formed on a tungsten cathode as a result of the motion of the cathode spot of a vacuum arc over the cathode surface have been examined. It has been found that the average mass of a cathode microprotrusion having the shape of a solidified jet is approximately equal to the mass of ions removed from the cathode within the lifetime of a cathode spot cell carrying a current of several amperes. The time of formation of a new liquid-metal jet under the action of the reactive force of the plasma ejected by the cathode spot is about 10?ns, which is comparable to the lifetime of a cell. The growth rate of a liquid-metal jet is ?10{sup 4}?cm/s. The geometric shape and size of a solidified jet are such that a new explosive emission center (spot cell) can be initiated within several nanoseconds during the interaction of the jet with the dense cathode plasma. This is the underlying mechanism of the self-sustained operation of a vacuum arc.

  2. Modeling of fundamental phenomena in welds

    SciTech Connect (OSTI)

    Zacharia, T.; Vitek, J.M. [Oak Ridge National Lab., TN (United States); Goldak, J.A. [Carleton Univ., Ottawa, Ontario (Canada); DebRoy, T.A. [Pennsylvania State Univ., University Park, PA (United States); Rappaz, M. [Ecole Polytechnique Federale de Lausanne (Switzerland); Bhadeshia, H.K.D.H. [Cambridge Univ. (United Kingdom)

    1993-12-31T23:59:59.000Z

    Recent advances in the mathematical modeling of fundamental phenomena in welds are summarized. State-of-the-art mathematical models, advances in computational techniques, emerging high-performance computers, and experimental validation techniques have provided significant insight into the fundamental factors that control the development of the weldment. The current status and scientific issues in the areas of heat and fluid flow in welds, heat source metal interaction, solidification microstructure, and phase transformations are assessed. Future research areas of major importance for understanding the fundamental phenomena in weld behavior are identified.

  3. Arc distribution during the vacuum arc remelting of Ti-6Al-4V

    SciTech Connect (OSTI)

    Woodside, Charles Rigel [U.S. DOE; King, Paul E. [U.S. DOE; Nordlund, Chris [ATI Albany Operations

    2013-01-01T23:59:59.000Z

    Currently, the temporal distribution of electric arcs across the ingot during vacuum arc remelting (VAR) is not a known or monitored process parameter. Previous studies indicate that the distribution of arcs can be neither diffuse nor axisymmetric about the center of the furnace. Correct accounting for the heat flux, electric current flux, and mass flux into the ingot is critical to achieving realistic solidification models of the VAR process. The National Energy Technology Laboratory has developed an arc position measurement system capable of locating arcs and determining the arc distribution within an industrial VAR furnace. The system is based on noninvasive magnetic field measurements and a VAR specific form of the Biot–Savart law. The system was installed on a coaxial industrial VAR furnace at ATI Albany Operations in Albany, OR. This article reports on the different arc distributions observed during production of Ti-6Al-4V. It is shown that several characteristic arc distribution modes can develop. This behavior is not apparent in the existing signals used to control the furnace, indicating the measurement system is providing new information. It is also shown that the different arc distribution modes observed may impact local solidification times, particularly at the side wall.

  4. Detection of arcs in automotive electrical systems

    E-Print Network [OSTI]

    Mishrikey, Matthew David

    2005-01-01T23:59:59.000Z

    At the present time, there is no established method for the detection of DC electric arcing. This is a concern for forthcoming advanced automotive electrical systems which consist of higher DC electric power bus voltages, ...

  5. The arc cloud complex: a case study

    E-Print Network [OSTI]

    Miller, Robert Loren

    1984-01-01T23:59:59.000Z

    THE ARC CLOUD COMPLEX: A CASE STUDY A Thesis by ROBERT LOREN MILLER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1984 Major Subject...: Meteorology THE ARC CLOUD COMPLEX; A CASE STUDY A Thesis by ROBERT LOREN MILLER Approved as to style and content by: Kenneth C. Brundidge (Chairman of Committee) Walter K. Henry (Member) Marshall ~ Mcparland (Member) James R. Scog s (Head...

  6. Prediction of Welding Distortion Panagiotis Michaleris and Andrew DeBiccari

    E-Print Network [OSTI]

    Michaleris, Panagiotis

    1 Prediction of Welding Distortion Panagiotis Michaleris and Andrew DeBiccari Edison Welding Institute Columbus, Ohio ABSTRACT. This paper presents a numerical analysis technique for predicting welding induced distortion. The technique combines two dimensional welding simulations with three dimensional

  7. Tungsten and tungsten alloy powder metallurgy: Powder production and applications excluding lamps. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect (OSTI)

    Not Available

    1994-04-01T23:59:59.000Z

    The bibliography contains citations of selected patents concerning the preparation of metallic and ceramic powders of tungsten and tungsten alloys, including applications of these materials. The hydrogen reduction of tungsten compounds together with alloying element compounds produce forms with characteristics of high density, hardness, wear resistance, high melting points, and abrasiveness. Topics include production of cathodes, heaters, filament wires, electrical contacts, acoustic absorbers, high-density sheets and coatings, hard penetrators, and tungsten carbide and metallized ceramics. (Contains a minimum of 109 citations and includes a subject term index and title list.)

  8. Novel Reactor Design and Metrology Study for Tungsten ALD process

    E-Print Network [OSTI]

    Rubloff, Gary W.

    species Viscous flow condition Short gas residence time Fast gas switching Reactant + carrier gas Multiple Operation Modes Exposure Purge Small reactor volume Throttle Valve 5 torr 10-5 Torr carrier gas 5 torr 10Novel Reactor Design and Metrology Study for Tungsten ALD process Laurent Henn-Lecordier, Wei Lei

  9. Retention of Hydrogen Isotopes in Neutron Irradiated Tungsten

    SciTech Connect (OSTI)

    Yuji Hatano; Masashi Shimada; Yasuhisa Oya; Guoping Cao; Makoto Kobayashi; Masanori Hara; Brad J. Merrill; Kenji Okuno; Mikhail A. Sokolov; Yutai Katoh

    2013-03-01T23:59:59.000Z

    To investigate the effects of neutron irradiation on hydrogen isotope retention in tungsten, disk-type specimens of pure tungsten were irradiated in the High Flux Isotope Reactor in Oak Ridge National Laboratory followed by exposure to high flux deuterium (D) plasma in Idaho National Laboratory. The results obtained for low dose n-irradiated specimens (0.025 dpa for tungsten) are reviewed in this paper. Irradiation at coolant temperature of the reactor (around 50 degrees C) resulted in the formation of strong trapping sites for D atoms. The concentrations of D in n-irradiated specimens were ranging from 0.1 to 0.4 mol% after exposure to D plasma at 200 and 500 degrees C and significantly higher than those in non-irradiated specimens because of D-trapping by radiation defects. Deep penetration of D up to a depth of 50-100 µm was observed at 500 degrees C. Release of D in subsequent thermal desorption measurements continued up to 900 degrees C. These results were compared with the behaviour of D in ion-irradiated tungsten, and distinctive features of n-irradiation were discussed.

  10. Tungsten-yttria carbide coating for conveying copper

    DOE Patents [OSTI]

    Rothman, Albert J. (Livermore, CA)

    1993-01-01T23:59:59.000Z

    A method is provided for providing a carbided-tungsten-yttria coating on the interior surface of a copper vapor laser. The surface serves as a wick for the condensation of liquid copper to return the condensate to the interior of the laser for revolatilization.

  11. Author's personal copy Tungsten in Hawaiian picrites: A compositional model

    E-Print Network [OSTI]

    Mcdonough, William F.

    form 15 April 2009; available online 3 May 2009 Abstract Concentrations of tungsten (W) and uranium (U is three-times as enriched as the Depleted MORB Mantle (DMM; 3.0 ± 2.3 ng/g). The relatively high of the recycling of W-rich oceanic crust and sediment into a depleted mantle source, such as the depleted MORB

  12. Development of Bulk Nanocrystalline Cemented Tungsten Carbide for Industrial Applicaitons

    SciTech Connect (OSTI)

    Z. Zak Fang, H. Y. Sohn

    2009-03-10T23:59:59.000Z

    This report contains detailed information of the research program entitled "Development of Bulk Nanocrystalline Cemented Tungsten Carbide Materials for Industrial Applications". The report include the processes that were developed for producing nanosized WC/Co composite powders, and an ultrahigh pressure rapid hot consolidation process for sintering of nanosized powders. The mechanical properties of consolidated materials using the nanosized powders are also reported.

  13. Ion source with improved primary arc collimation

    DOE Patents [OSTI]

    Dagenhart, William K. (Oak Ridge, TN)

    1985-01-01T23:59:59.000Z

    An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power, thereby preventing the exposure of the anode to the full arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

  14. Pulsed Magnetic Welding for Advanced Core and Cladding Steel

    SciTech Connect (OSTI)

    Cao, Guoping; Yang, Yong

    2013-12-19T23:59:59.000Z

    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.

  15. Method and apparatus for real time weld monitoring

    DOE Patents [OSTI]

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

    1997-01-01T23:59:59.000Z

    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.

  16. Vibration welding system with thin film sensor

    DOE Patents [OSTI]

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

    2014-03-18T23:59:59.000Z

    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.

  17. COMPARISON OF AIR AND DEUTERIUM ON PINCH WELD BOND APPEARANCE

    SciTech Connect (OSTI)

    Korinko, P

    2005-10-11T23:59:59.000Z

    The effect that air and deuterium internal atmospheres have on the pinch weld bond quality was evaluated by conducting a scoping study using type 304L stainless steel LF-7 test stems that were fabricated for an associated study. Welds were made under cool, yet nominal conditions to exacerbate the influence of the atmosphere. The bond quality of the welds was directly related to the internal atmosphere with the air atmosphere welds being of lower quality than the deuterium atmosphere welds for nominally identical welding conditions.

  18. Low Distortion Welded Joints for NCSX

    SciTech Connect (OSTI)

    M. Denault, M Viola, W. England

    2009-02-19T23:59:59.000Z

    The National Compact Stellarator Experiment (NCSX) required precise positioning of the field coils in order to generate suitable magnetic fields. A set of three modular field coils were assembled to form the Half Field-Period Assemblies (HPA). Final assembly of the HPA required a welded shear plate to join individual coils in the nose region due to the geometric limitations and the strength constraints. Each of the modular coil windings was wound on a stainless steel alloy (Stellalloy) casting. The alloy is similar to austenitic 316 stainless steel. During the initial welding trials, severe distortion, of approximately 1/16", was observed in the joint caused by weld shrinkage. The distortion was well outside the requirements of the design. Solutions were attempted through several simultaneous routes. The joint design was modified, welding processes were changed, and specialized heat reduction techniques were utilized. A final joint design was selected to reduce the amount of weld material needed to be deposited, while maintaining adequate penetration and strength. Several welding processes and techniques using Miller Axcess equipment were utilized that significantly reduced heat input. The final assembly of the HPA was successful. Distortion was controlled to 0.012", well within the acceptable design tolerance range of 0.020" over a 3.5 foot length.

  19. Pitfalls of tungsten multileaf collimator in proton beam therapy

    SciTech Connect (OSTI)

    Moskvin, Vadim; Cheng, Chee-Wai; Das, Indra J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States) and Indiana University Health Proton Therapy Center (Formerly Midwest Proton Radiotherapy Institute), Bloomington, Indiana 47408 (United States)

    2011-12-15T23:59:59.000Z

    Purpose: Particle beam therapy is associated with significant startup and operational cost. Multileaf collimator (MLC) provides an attractive option to improve the efficiency and reduce the treatment cost. A direct transfer of the MLC technology from external beam radiation therapy is intuitively straightforward to proton therapy. However, activation, neutron production, and the associated secondary cancer risk in proton beam should be an important consideration which is evaluated. Methods: Monte Carlo simulation with FLUKA particle transport code was applied in this study for a number of treatment models. The authors have performed a detailed study of the neutron generation, ambient dose equivalent [H*(10)], and activation of a typical tungsten MLC and compared with those obtained from a brass aperture used in a typical proton therapy system. Brass aperture and tungsten MLC were modeled by absorber blocks in this study, representing worst-case scenario of a fully closed collimator. Results: With a tungsten MLC, the secondary neutron dose to the patient is at least 1.5 times higher than that from a brass aperture. The H*(10) from a tungsten MLC at 10 cm downstream is about 22.3 mSv/Gy delivered to water phantom by noncollimated 200 MeV beam of 20 cm diameter compared to 14 mSv/Gy for the brass aperture. For a 30-fraction treatment course, the activity per unit volume in brass aperture reaches 5.3 x 10{sup 4} Bq cm{sup -3} at the end of the last treatment. The activity in brass decreases by a factor of 380 after 24 h, additional 6.2 times after 40 days of cooling, and is reduced to background level after 1 yr. Initial activity in tungsten after 30 days of treating 30 patients per day is about 3.4 times higher than in brass that decreases only by a factor of 2 after 40 days and accumulates to 1.2 x 10{sup 6} Bq cm{sup -3} after a full year of operation. The daily utilization of the MLC leads to buildup of activity with time. The overall activity continues to increase due to {sup 179}Ta with a half-life of 1.82 yr and thus require prolonged storage for activity cooling. The H*(10) near the patient side of the tungsten block is about 100 {mu}Sv/h and is 27 times higher at the upstream side of the block. This would lead to an accumulated dose for therapists in a year that may exceed occupational maximum permissible dose (50 mSv/yr). The value of H*(10) at the upstream surface of the tungsten block is about 220 times higher than that of the brass. Conclusions: MLC is an efficient way for beam shaping and overall cost reduction device in proton therapy. However, based on this study, tungsten seems to be not an optimal material for MLC in proton beam therapy. Usage of tungsten MLC in clinic may create unnecessary risks associated with the secondary neutrons and induced radioactivity for patients and staff depending on the patient load. A careful selection of material for manufacturing of an optimal MLC for proton therapy is thus desired.

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

    DOE Patents [OSTI]

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

    1980-01-03T23:59:59.000Z

    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.

  1. Apparatus for maintaining alignment of a shrinking weld joint in an electron-beam welding operation

    DOE Patents [OSTI]

    Trent, Jett B. (Knoxville, TN); Murphy, Jimmy L. (Oak Ridge, TN)

    1981-01-01T23:59:59.000Z

    The present invention is directed to an apparatus for automatically maintaining a shrinking weld joint in alignment with an electron beam during an electron-beam multipass-welding operation. The apparatus utilizes a biasing device 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 is 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.

  2. Comparison of Bond Scission Sequence of Methanol on Tungsten Monocarbide and Pt-Modified Tungsten Monocarbide

    SciTech Connect (OSTI)

    Liu, P.; Stottlemyer, A.L.; Chen, J.G.

    2010-09-14T23:59:59.000Z

    The ability to control the bond scission sequence of O-H, C-H, and C-O bonds is of critical importance in the effective utilization of oxygenate molecules, such as in reforming reactions and in alcohol fuel cells. In the current study, we use methanol as a probe molecule to demonstrate the possibility to control the decomposition pathways by supporting monolayer coverage of Pt on a tungsten monocarbide (WC) surface. Density functional theory (DFT) results reveal that on the WC and Pt/WC surfaces CH{sub 3}OH decomposes via O-H bond scission to form the methoxy (*CH{sub 3} O) intermediate. The subsequent decomposition of methoxy on the WC surface occurs through the C-O bond scission to form *CH{sub 3}, which reacts with surface *H to produce CH{sub 4}. In contrast, the decomposition of methoxy on the Pt/WC surface favors the C-H bond scission to produce *CH{sub 2} O, which prevents the formation of the *CH{sub 3} species and leads to the formation of a *CO intermediate through subsequent deprotonation steps. The DFT predictions are validated using temperature programmed desorption to quantify the gas-phase product yields and high resolution electron energy loss spectroscopy to determine the surface intermediates from methanol decomposition on Pt, WC, and Pt/WC surfaces.

  3. Ion source with improved primary arc collimation

    DOE Patents [OSTI]

    Dagenhart, W.K.

    1983-12-16T23:59:59.000Z

    An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

  4. CUTTING -WELDING -HOT WORKS REQUIRED NOTIFICATION TO CUFD

    E-Print Network [OSTI]

    Stuart, Steven J.

    CUTTING - WELDING - HOT WORKS REQUIRED NOTIFICATION TO CUFD Instructions: Fill out this form in its Time for work: Description of Work: Brazing Roofing Sweating WeldingSolderingCutting Other

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

    Energy Savers [EERE]

    Stir Spot Welding of Advanced High Strength Steels (AHSS) Friction Stir Spot Welding of Advanced High Strength Steels (AHSS) Presentation from the U.S. DOE Office of Vehicle...

  6. Assessing Exposures to Particulate Matter and Manganese in Welding Fumes

    E-Print Network [OSTI]

    LIU, SA

    2010-01-01T23:59:59.000Z

    helmets.   American Industrial Hygiene Association Journal welding.   American Industrial Hygiene Association Journal electrodes.  American  Industrial Hygiene Association 

  7. Prediction of cooling rate and microstructure in laser spot welds

    E-Print Network [OSTI]

    Cambridge, University of

    during laser spot welding of low alloy steel. A transient heat transfer model that takes into account

  8. In vivo interactions between tungsten microneedles and peripheral nerves

    E-Print Network [OSTI]

    Pier Nicola Sergi; Winnie Jensen; Silvestro Micera; Ken Yoshida

    2013-08-02T23:59:59.000Z

    Tungsten microneedles are currently used to insert neural electrodes into living peripheral nerves. However, the biomechanics underlying these procedures is not yet well characterized. For this reason, the aim of this work was to model the interactions between these microneedles and living peripheral nerves. A simple mathematical framework was especially provided to model both compression of the external layer of the nerve (epineurium) and the interactions resulting from penetration of the main shaft of the microneedle inside the living nerves. The instantaneous Young's modulus, compression force, the work needed to pierce the tissue, puncturing pressure, and the dynamic friction coefficient between the tungsten microneedles and living nerves were quantified starting from acute experiments, aiming to reproduce the physical environment of real implantations. Indeed, a better knowledge of the interactions between microneedles and peripheral nerves may be useful to improve the effectiveness of these insertion techniques, and could represent a key factor for designing robot-assisted procedures tailored for peripheral nerve insertion.

  9. Development of positron annihilation spectroscopy for characterizing neutron irradiated tungsten

    SciTech Connect (OSTI)

    C.N. Taylor; M. Shimada; D.W. Akers; M.W. Drigert; B.J. Merrill; Y. Hatano

    2013-05-01T23:59:59.000Z

    Tungsten samples (6 mm diameter, 0.2 mm thick) were irradiated to 0.025 and 0.3 dpa with neutrons in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Samples were then exposed to deuterium plasma in the tritium plasma experiment (TPE) at 100, 200 and 500ºC to a total fluence of 1 x 1026 m-2. Nuclear reaction analysis (NRA) and Doppler broadening positron annihilation spectroscopy (DB-PAS) were performed at various stages to characterize damage and retention. We present the first known results of neutron damaged tungsten characterized by DB-PAS in order to study defect concentration. Two positron sources, 22Na and 68Ge, probe ~58 µm and through the entire 200 µm thick samples, respectively. DB-PAS results reveal clear differences between the various irradiated samples. These results, and the calibration of DB-PAS to NRA data are presented.

  10. Studies on nickel-tungsten oxide thin films

    SciTech Connect (OSTI)

    Usha, K. S. [Department of Physics, Alagappa University, Karaikudi - 630 004 (India); Sivakumar, R., E-mail: krsivakumar1979@yahoo.com [Directorate of Distance Education, Alagappa University, Karaikudi - 630 004 (India); Sanjeeviraja, C. [Department of Physics, Alagappa Chettiar College of Engineering and Technology, Karaikudi - 630 004 (India)

    2014-10-15T23:59:59.000Z

    Nickel-Tungsten oxide (95:5) thin films were prepared by rf sputtering at 200W rf power with various substrate temperatures. X-ray diffraction study reveals the amorphous nature of films. The substrate temperature induced decrease in energy band gap with a maximum transmittance of 71%1 was observed. The Micro-Raman study shows broad peaks at 560 cm{sup ?1} and 1100 cm{sup ?1} correspond to Ni-O vibration and the peak at 860 cm{sup ?1} can be assigned to the vibration of W-O-W bond. Photoluminescence spectra show two peaks centered on 420 nm and 485 nm corresponding to the band edge emission and vacancies created due to the addition of tungsten, respectively.

  11. Thermal-treatment effect on the photoluminescence and gas-sensing properties of tungsten oxide nanowires

    SciTech Connect (OSTI)

    Sun, Shibin [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, Shandong (China)] [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, Shandong (China); Chang, Xueting [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100, Shandong (China)] [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100, Shandong (China); Li, Zhenjiang, E-mail: zjli126@126.com [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, Shandong (China)] [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, Shandong (China)

    2010-09-15T23:59:59.000Z

    Single-crystalline non-stoichiometric tungsten oxide nanowires were initially prepared using a simple solvothermal method. High resolution transmission electron microscopy (HRTEM) investigations indicate that the tungsten oxide nanowires exhibit various crystal defects, including stacking faults, dislocations, and vacancies. A possible defect-induced mechanism was proposed to account for the temperature-dependent morphological evolution of the tungsten oxide nanowires under thermal processing. Due to the high specific surface areas and non-stoichiometric crystal structure, the original tungsten oxide nanowires were highly sensitive to ppm level ethanol at room temperature. Thermal treatment under dry air condition was found to deteriorate the selectivity of room-temperature tungsten oxide sensors, and 400 {sup o}C may be considered as the top temperature limit in sensor applications for the solvothermally-prepared nanowires. The photoluminescence (PL) characteristics of tungsten oxide nanowires were also strongly influenced by thermal treatment.

  12. Tungsten spectroscopy relevant to the diagnostics development of ITER divertor plasmas

    SciTech Connect (OSTI)

    Clementson, J; Beiersdorfer, P; Magee, E W; McLean, H S; Wood, R D

    2009-12-01T23:59:59.000Z

    The ITER tokamak will have tungsten divertor tiles and, consequently, the divertor plasmas are expected to contain tungsten ions. The spectral emission from these ions can serve to diagnose the divertor for plasma parameters such as tungsten concentrations, densities, ion and electron temperatures, and flow velocities. The ITER divertor plasmas will likely have densities around 10{sup 14-15} cm{sup -3} and temperatures below 150 eV. These conditions are similar to the plasmas at the Sustained Spheromak Physics Experiment (SSPX) in Livermore. To simulate ITER divertor plasmas, a tungsten impurity was introduced into the SSPX spheromak by prefilling it with tungsten hexacarbonyl prior to the usual hydrogen gas injection and initiation of the plasma discharge. The possibility of using the emission from low charge state tungsten ions to diagnose tokamak divertor plasmas has been investigated using a high-resolution extreme ultraviolet spectrometer.

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

    SciTech Connect (OSTI)

    Li, Leijun

    2012-11-02T23:59:59.000Z

    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.

  14. Ion source based on the cathodic arc

    DOE Patents [OSTI]

    Sanders, D.M.; Falabella, S.

    1994-02-01T23:59:59.000Z

    A cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated, is described. An array of electrically isolated rings positioned in the source serves the dual purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles. 3 figures.

  15. REAL TIME ULTRASONIC ALUMINUM SPOT WELD MONITORING SYSTEM

    SciTech Connect (OSTI)

    Regalado, W. Perez; Chertov, A. M.; Maev, R. Gr. [Institute for Diagnostic Imaging Research, Physics Department, University of Windsor, 292 Essex Hall, 401 Sunset Ave. N9B 3P4 Windsor, Ontario (Canada)

    2010-02-22T23:59:59.000Z

    Aluminum alloys pose several properties that make them one of the most popular engineering materials: they have excellent corrosion resistance, and high weight-to-strength ratio. Resistance spot welding of aluminum alloys is widely used today but oxide film and aluminum thermal and electrical properties make spot welding a difficult task. Electrode degradation due to pitting, alloying and mushrooming decreases the weld quality and adjustment of parameters like current and force is required. To realize these adjustments and ensure weld quality, a tool to measure weld quality in real time is required. In this paper, a real time ultrasonic non-destructive evaluation system for aluminum spot welds is presented. The system is able to monitor nugget growth while the spot weld is being made. This is achieved by interpreting the echoes of an ultrasound transducer located in one of the welding electrodes. The transducer receives and transmits an ultrasound signal at different times during the welding cycle. Valuable information of the weld quality is embedded in this signal. The system is able to determine the weld nugget diameter by measuring the delays of the ultrasound signals received during the complete welding cycle. The article presents the system performance on aluminum alloy AA6022.

  16. CORRECTION OF BUTT-WELDING INDUCED DISTORTIONS BY LASER FORMING

    E-Print Network [OSTI]

    Yao, Y. Lawrence

    CORRECTION OF BUTT-WELDING INDUCED DISTORTIONS BY LASER FORMING Peng Cheng, Andrew J. Birnbaum, Y Egland Technology and Solutions Division Caterpillar Inc. Peoria, IL KEYWORDS Welding, Distortion, Correction, Laser Forming ABSTRACT Welding-induced distortion is an intrinsic phenomenon arising due

  17. Some European Developments in Welding Consumables L. Karlsson

    E-Print Network [OSTI]

    Cambridge, University of

    Some European Developments in Welding Consumables L. Karlsson and H. K. D. H. Bhadeshia* November 1 a selected survey of incisive research on novel welding consumables which contribute to the structural and insight based on metallurgical experience. We congratulate the Japan Welding Society for organising

  18. A PARANETRIC STlJDY OF THE ELECTROSLAG WELDING PROCESS

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) ) A PARANETRIC STlJDY OF THE ELECTROSLAG WELDING PROCESS by W. S. Ricci and T. W. Eagar conducted on electroslag welds to statistically evaluate the effect of i ndependent process variables upon dependent process responses consisting of heat affected zone size, dilution, form factor, welding speed

  19. Electromagnetically and Thermally Driven Flow Phenomena in Electroslag Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) Electromagnetically and Thermally Driven Flow Phenomena in Electroslag Welding A. H. DILAWARI, J for the Electroslag Welding Process. In the formulation, allowance has been made {or both etee- tromagnetic and b in the use of electroslag welding (ESW), particularly for the construction of thick walled pressure vessels

  20. Minimization of welding residual stress and distortion in large structures

    E-Print Network [OSTI]

    Michaleris, Panagiotis

    1 Minimization of welding residual stress and distortion in large structures P. Michaleris at Champaign Urbana, Urbana, IL Abstract Welding distortion in large structures is usually caused by buckling due to the residual stress. In cases where the design is fixed and minimum weld size requirements

  1. Welding residual stresses in ferritic power plant steels

    E-Print Network [OSTI]

    Cambridge, University of

    REVIEW Welding residual stresses in ferritic power plant steels J. A. Francis*1 , H. K. D. H require therefore, an accounting of residual stresses, which often are introduced during welding. To do in the estimation of welding residual stresses in austenitic stainless steels. The progress has been less convincing

  2. .Heat Generation Patterns and Temperature Profiles in_ Electroslag Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    l .Heat Generation Patterns and Temperature Profiles in_ Electroslag Welding ) · T. DEBROY, J in the slag and metal phases for an electroslag welding system. It is shown that the current is significantly larger for the electroslag welding process than that of the electroslao refinino process operating

  3. CONFORMAL WELDING AND KOEBE'S THEOREM CHRISTOPHER J. BISHOP

    E-Print Network [OSTI]

    Bishop, Christopher

    CONFORMAL WELDING AND KOEBE'S THEOREM CHRISTOPHER J. BISHOP Abstract. It is well known that not every orientation preserving homeomorphism of the circle to itself is a conformal welding, but in this paper we prove several results which state that every homeomorphism is \\almost" a welding in a precise

  4. Friction Stir Welding John Hinch and John Rudge

    E-Print Network [OSTI]

    Rudge, John

    Friction Stir Welding John Hinch and John Rudge September 11, 2002 1 Introduction Friction Stir Welding is an innovative technique for joining two pieces of metal. A rapidly rotating tool is pushed that a good model of friction stir welding should be able to predict - the power, the force, the temperature

  5. Cinematography of Resistance Spot Welding of Galvanized Steel Sheet

    E-Print Network [OSTI]

    Eagar, Thomas W.

    Cinematography of Resistance Spot Welding of Galvanized Steel Sheet Preweld and postweld current modifications on the resistance spot welding of galvanized steel sheet ·are analyzed using high phenomena through· out the weld process are discussed. In addition. the duration of current modifi· cation

  6. Experimental validation of finite element codes for welding deformations

    E-Print Network [OSTI]

    Boyer, Edmond

    Experimental validation of finite element codes for welding deformations H. M. Aarbogha,b, , M Institute for Energy Technology, N-2027 Kjeller, Norway. Abstract A single pass Metal Inert Gas welding which numerical codes quantifying welding stresses can be validated. It includes a mov- ing heat source

  7. Conformal welding and the sewing equations Eric Schippers

    E-Print Network [OSTI]

    Schippers, Eric

    Conformal welding and the sewing equations Eric Schippers Department of Mathematics University of Manitoba Winnipeg Rutgers 2014 Eric Schippers (Manitoba) Conformal welding Rutgers 1 / 41 #12;Introduction Schippers (Manitoba) Conformal welding Rutgers 2 / 41 #12;Introduction Our work in general We began

  8. A shape optimization formulation of weld pool determination. , A. Ellabibb

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    The determination of temperature field in a welding process permits the control of mechanical effects (residual consists in finding the weld pool and T the temperature gradient in the workpiece, solution of: K T xA shape optimization formulation of weld pool determination. A. Chakiba , A. Ellabibb , A

  9. Apparatus for the concurrent inspection of partially completed welds

    DOE Patents [OSTI]

    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

    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.

  10. Photoionization of the valence shells of the neutral tungsten atom

    E-Print Network [OSTI]

    Ballance, Connor P

    2015-01-01T23:59:59.000Z

    Results from large-scale theoretical cross section calculations for the total photoionization of the 4f, 5s, 5p and 6s orbitals of the neutral tungsten atom using the Dirac Coulomb R-matrix approximation (DARC: Dirac-Atomic R-matrix codes) are presented. Comparisons are made with previous theoretical methods and prior experimental measurements. In previous experiments a time-resolved dual laser approach was employed for the photo-absorption of metal vapours and photo-absorption measurements on tungsten in a solid, using synchrotron radiation. The lowest ground state level of neutral tungsten is $\\rm 5p^6 5d^4 6s^2 \\; {^5}D_{\\it J}$, with $\\it J$=0, and requires only a single dipole matrix for photoionization. To make a meaningful comparison with existing experimental measurements, we statistically average the large-scale theoretical PI cross sections from the levels associated with the ground state $\\rm 5p^6 5d^4 6s^2 \\; {^5}D_{\\it J}[{\\it J}=0,1,2,3,4]$ levels and the $\\rm 5d^56s \\; ^7S_3$ excited metastable...

  11. Synthesis, Crystal Structure, and Elastic Properties of Novel Tungsten Nitrides

    SciTech Connect (OSTI)

    Wang, Shanmin; Yu, Xiaohui; Lin, Zhijun; Zhang, Ruifeng; He, Duanwei; Qin, Jiaqian; Zhu, Jinlong; Han, Jiantao; Wang, Lin; Mao, Ho-kwang; Zhang, Jianzhong; Zhao, Yusheng (UNLV); (Ehime U); (CIW); (Sichuan U.); (LANL)

    2012-12-13T23:59:59.000Z

    Among transition metal nitrides, tungsten nitrides possess unique and/or superior chemical, mechanical, and thermal properties. Preparation of these nitrides, however, is challenging because the incorporation of nitrogen into tungsten lattice is thermodynamically unfavorable at atmospheric pressure. To date, most materials in the W-N system are in the form of thin films produced by nonequilibrium processes and are often poorly crystallized, which severely limits their use in diverse technological applications. Here we report synthesis of tungsten nitrides through new approaches involving solid-state ion exchange and nitrogen degassing under pressure. We unveil a number of novel nitrides including hexagonal and rhombohedral W{sub 2}N{sub 3}. The final products are phase-pure and well-crystallized in bulk forms. For hexagonal W{sub 2}N{sub 3}, hexagonal WN, and cubic W3N4, they exhibit elastic properties rivaling or even exceeding cubic-BN. All four nitrides are prepared at a moderate pressure of 5 GPa, the lowest among high-pressure synthesis of transition metal nitrides, making it practically feasible for massive and industrial-scale production.

  12. Arc Geometry and Algebra: Foliations, Moduli ... - Purdue University

    E-Print Network [OSTI]

    2012-07-04T23:59:59.000Z

    the simplicial complex which has one simplex for each arc family ? with the i–the face ..... 1.6.2 Loop graph of an arc family: A geometric construction of the dual.

  13. arc ion sources: Topics by E-print Network

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

    and performance of vacuum arc ion sources. Brown, I 2013-01-01 2 Development of High Efficiency Versatile Arc Discharge Ion Source (VADIS) at CERN Isolde CERN Preprints Summary: We...

  14. arc ion source: Topics by E-print Network

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

    and performance of vacuum arc ion sources. Brown, I 2013-01-01 2 Development of High Efficiency Versatile Arc Discharge Ion Source (VADIS) at CERN Isolde CERN Preprints Summary: We...

  15. Correlations between SAR arc intensity and solar and geomagnetic activity

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ±1960, Rees and Akasofu (1963) and Roach and Roach (1963) found that there are correlations of the SAR arc

  16. The Inception of the ArcGIS Marine Data Model

    E-Print Network [OSTI]

    Wright, Dawn Jeannine

    . Shapefiles and coverages can now be easily loaded as feature classes in the ArcGISTM geodatabase for more

  17. Actively controlled vibration welding system and method

    DOE Patents [OSTI]

    Cai, Wayne W.; Kang, Bongsu; Tan, Chin-An

    2013-04-02T23:59:59.000Z

    A vibration welding system includes a controller, welding horn, an active material element, and anvil assembly. The assembly may include an anvil body connected to a back plate and support member. The element, e.g., a piezoelectric stack or shape memory alloy, is positioned with respect to the assembly. The horn vibrates in a desirable first direction to form a weld on a work piece. The element controls any vibrations in a second direction by applying calibrated response to the anvil body in the second direction. A method for controlling undesirable vibrations in the system includes positioning the element with respect to the anvil assembly, connecting the anvil body to the support member through the back plate, vibrating the horn in a desirable first direction, and transmitting an input signal to the element to control vibration in an undesirable second direction.

  18. Results of crack-arrest tests on two irradiated high-copper welds

    SciTech Connect (OSTI)

    Iskander, S.K.; Corwin, W.R.; Nanstead, R.K. (Oak Ridge National Lab., TN (USA))

    1990-12-01T23:59:59.000Z

    The objective of this study was to determine the effect of neutron irradiation on the shift and shape of the lower-bound curve to crack-arrest data. Two submerged-arc welds with copper contents of 0.23 and 0.31 wt % were commercially fabricated in 220-mm-thick plate. Crack-arrest specimens fabricated from these welds were irradiated at a nominal temperature of 288{degree}C to an average fluence of 1.9 {times} 10{sup 19} neutrons/cm{sup 2} (>1 MeV). Evaluation of the results shows that the neutron-irradiation-induced crack-arrest toughness temperature shift is about the same as the Charpy V-notch impact temperature shift at the 41-J energy level. The shape of the lower-bound curves (for the range of test temperatures covered) did not seem to have been altered by irradiation compared to those of the ASME K{sub Ia} curve. 9 refs., 21 figs., 10 tabs.

  19. Way to reduce arc voltage losses in hybrid thermionic converters

    SciTech Connect (OSTI)

    Tskhakaya, V.K.; Yarygin, V.I.

    1982-03-01T23:59:59.000Z

    Experimental results are reported concerning the output and emission characteristics of the arc and hybrid regimes in a plane-parallel thermionic converter with Pt--Zr--O electrode pair. It is shown that arc voltage losses can be reduced to values below those obtainable in ordinary arc thermionic converters.

  20. Evaluation of the clinical usefulness of modulated Arc treatment

    E-Print Network [OSTI]

    Lee, Young Kyu; Kim, Yeon Sil; Choi, Byung Ock; Nam, Sang Hee; Park, Hyeong Wook; Kim, Shin Wook; Shin, Hun Joo; Lee, Jae Choon; Kim, Ji Na; Park, Sung Kwang; Kim, Jin Young; Kang, Young-Nam

    2015-01-01T23:59:59.000Z

    The purpose of this study is to evaluate the clinical usefulness of modulated arc (mARC) treatment techniques. The mARC treatment plans of the non-small cell lung cancer (NSCLC) patients were performed in order to verify the clinical usefulness of mARC. A pre study was conducted to find the most competent plan condition of mARC treatment and the usefulness of mARC treatment plan was evaluated by comparing it with the other Arc treatment plans such as Tomotherapy and RapidArc. In the case of mARC, the optimal condition for the mARC plan was determined by comparing the dosimetric performance of the mARC plans with the use of various parameters. The various parameters includes the photon energies (6 MV, 10 MV), optimization point angle (6{\\deg}-10{\\deg} intervals), and total segment number (36-59 segment). The best dosimetric performance of mARC was observed at 10 MV photon energy and the point angle 6 degree, and 59 segments. The each treatment plans of three different techniques were compared with the followin...