Comparison of residual stress induced by TIG and LBW in girth weld of AISI 304 stainless steel pipes

A combined heat source model involving two-part conical models and a cylindrical model was dramatically developed to predict the thermal process of laser beam welding, and a double ellipsoid heat source model was employed to simulate the tungsten inert gas welding process. A nonlinear mixed hardening model and an annealing temperature were considered to character the thermo-elastic-plastic stress-strain behaviour. The developed numerical simulation methods were validated by the experimental measurements. In both cases, excellent agreement was obtained between predicted and measured weld bead macrographs and temperature histories, as well as the welding residual stresses. In terms of the welding residual stress, deformation and production efficiency, the LBW is more advantageous than the TIG on the welding of AISI 304 stainless steel pipes.