Improving the mechanical performance of a resistance spot welded 1200 MPa TBF steel

Abstract In the present work different approaches to improve mechanical properties of a resistance spot welded 1200 MPa transformation induced plasticity-aided bainitic ferrite steel are evaluated. An extension welding time results in coarsening microstructure outer fusion zone and maximum force derived by cross tension strength test did not significantly. A temper pulse after long cooling leads pronounced softening zone, as determined hardness mapping, which resulted enhanced weld properties. recrystallization modifies shape prior austenite grains at was visualized with electron backscatter diffraction. This also significant improvement force. For all failure mode improved, can be attributed an increased fraction high angle grain boundaries edge zone.