Thermo-Mechanical Simulation of Hybrid Welding of DP/AISI 316 and TWIP/AISI 316 Dissimilar Weld

In this paper, hybrid laser-MAG (metal active gas) welding of twinning-induced plasticity (TWIP) and dual-phase (DP) steels with austenitic stainless steel (AISI316) was simulated by means of the finite element method. A thermo-mechanical model, which uses a 3D heat sources, was developed using the software SimufactWelding. The calculated dimensions, shape and distortion of the weld were compared with the experimental results, thence the model was validated. The metallurgical transformations for the DP steel were evaluated using the continuous cooling transformation (CCT) diagram and the calculated cooling rate. The numerical model predicted accurately the shape of the molten pool, the thermal cycles as well as the geometrical distortion of the butt weld. Therefore, the numerical model showed a good reliability and its potential for further development.