Mechanical and Microstructural Characterizations of Resistance Spot Welded Dissimilar TWIP/304L Stainless Steel

In this work, a dissimilar TWIP/304L stainless steel joint was welded with resistance spot welding technique. The weld joint was evaluated by tensile-shear tests, SEM, EBSD, elemental mapping techniques. According to results, TWIP steel side compromised the weakest side for all experiments. An interlayer between weld nugget and heat-affected zone of the TWIP were found where borderline of the grains was determined by rolling lines. The inhomogeneity originated at the rolling lines in TWIP steel behaved like secondary alloy, resulting in intergranular gaps. Metal carbides including Chromium carbide were detected at the joints. An interlayer between weld nuggets and the heat-affected zone of the 304L stainless steel was also observed but not directly affected the mechanical results.