Arc welding

About: Arc welding is a research topic. Over the lifetime, 25393 publications have been published within this topic receiving 168182 citations.

A Perspective on Arc Welding Research: The Importance of the Arc, Unresolved Questions and Future Directions

Abstract: The state-of-the-art on arc welding research is considered, with unresolved questions and future directions highlighted. Both diagnostics and modelling are discussed. The focus is on the arc plasma, and its interactions with the electrode and workpiece, in tungsten–inert-gas and metal–inert-gas welding. Areas in which the need for further work is identified include development of techniques to measure current density distributions, calculation of the distribution of different gasses in the arc plasma (for example vapours of different metallic elements when welding alloys), computational methods for modelling metal transfer, and treatments of the sheath regions. It is shown that a thorough understanding of the arc is important in welding research and development. For example, reliable calculation of the heat flux to the workpiece requires the interactions between the arc and electrodes to be considered. Computational models of welding that take into account these interactions can already predict the shape and depth of the weld pool. Extensions of these methods would enable the determination of important properties of the welded metal, such as microstructure, residual stress and distortion, raising the possibility of the development of a “virtual manufacturing” capability.

Method and apparatus for controlling and simultaneously displaying arc welding process parameters

Abstract: A system (and method) of controlling and simultaneously displaying arc welding torch parameters includes a power supply for supplying weld voltage and current to the torch in accordance with demand signals from a computer. The computer also supplies a demand motor speed to a motor for controlling the travel speed of the torch electrode relative to a workpiece or the fed rate of a filler wire to the weld area. The actual values of the weld voltage/current and the motor speed are fed back to the computer and displayed on a video color display in separate colors and in real time to enable on operator to readily correlate the actual with the demand parameter values. The position of the electrode relative to the workpiece is also fed back to the computer for presentation on the video display. In addition, deviations of the individual actual parameter values from acceptable tolerance limits are highlighted on the display.

Heat and fluid flow in complex joints during gas metal arc welding—Part II: Application to fillet welding of mild steel

Abstract: A numerical model described in part I [W. Zhang, C.-H. Kim, and T. DebRoy, J. Appl. Phys. 95, 5210 (2004)] was used to investigate the heat transfer and free surface flow during gas metal arc fillet welding of mild steel. Dimensional analysis was used to understand the importance of heat transfer by conduction and convection and the role of various driving forces on convection in the liquid weld pool. The calculated shape and size, finger penetration characteristic and solidified surface profile of the fillet welds were in fair agreement with the experimental results for various welding conditions. The calculated cooling rates were also in good agreement with independent experimental data. The effect of welding parameters on important weld bead characteristics was quantitatively studied using the numerical model. The results reported here indicate a significant promise for understanding and control of gas metal arc fillet welding processes based on fundamental principles of transport phenomena.

Comparison of energy consumption and environmental impact of friction stir welding and gas metal arc welding for aluminum

Abstract: One of the advantages of friction stir welding (FSW) is reduced energy consumption as compared to arc welding processes. This advantage has been predicted and qualitatively established. However, a quantitative analysis based on energy measurements during the processes and how to equitably compare them is missing. The objective of this work is to quantitatively compare the energy consumption associated with the creation of full-penetration welds in aluminum 6061-T6 workpieces by FSW and gas metal arc welding (GMAW) processes. The workpiece thicknesses for the two processes (5-mm-thick for FSW and 7.1-mm-thick for GMAW) are chosen such that the maximum tensile force sustained by the joints during tensile testing is similar. This accounts for material saving due to the higher ultimate tensile strength resulting from FSW. The energy consumed for any pre-processes, the welding processes, and post-processes was measured. Finally, a life cycle assessment (LCA) approach was used to determine and compare the environmental impact of FSW and GMAW. For the welding parameters used in this study joining by FSW consumes 42% less energy as compared to GMAW and utilizes approximately 10% less material for the design criteria of similar maximum tensile force. This leads to approximately 31% less greenhouse gas emissions for FSW as compared to GMAW. Both, the lower energy consumption during FSW, and involved pre and post processes contributed in the overall energy reduction.