Abstract: The numerical simulation of butt brazing process of Al/steel dissimilar metal sheet under different welding conditions was carried out by using finite element analysis software ANSYS. Two models are established for TIG arc heat source and cold source respectively. Comparative analyses of residual stress and deformation reveal that the argon quenching at low temperature in the process of welding can effectively reduce longitudinal residual stress and deformation in the weld, resulting in apparent reduction by 32.8% and 48.1%, respectively. In order to verify the validity and prove the accuracy of our finite element simulation results, a welding test of Al/steel dissimilar metal sheet was carried out. Through analytical comparisons of the predicted results of temperature field and stress field and with tested ones, it is verified the effectiveness of the numerical model. It has been shown that the residual stress and deformation in Al/steel sheet welds can be effectively controlled by argon quenching technology.

Key words: numerical simulation, welding with trailing cooling of argon gas, control of welding distortion, control of welding residual stress, aluminum alloy/steel