Resistance spot welding of dissimilar AISI 304 SS-AISI 1012 steel: Mechanical properties and numerical simulation

The present research reports the effects of resistance spot welding parameters like current intensity, welding time, and electrode force on mechanical properties and the nugget size of dissimilar AISI 304 stainless steel and AISI 1012 low-carbon weldments. The current intensity values were selected as 7.7, 8.2, and 9.7 kA. The welding times and electrode forces were chosen as 6, 10, and 16 cycles, and 2300, 2500, and 2900 N, respectively. The tensile-shear test analyzed the strength of the joints. Results depicted that all three welding parameters affect the mechanical properties of the joints: increasing the current intensity and welding time increased the strength of the joints; however, the joint strength decreased with the increase of the electrode force. Meanwhile, an optimum current intensity of 9.7 kA, a welding time of 10 cycles, and an electrode force of 2700 N were defined as the optimum parameters to obtain the maximum joint strength. The fracture mode after the tensile testing was a pull-out failure. Furthermore, the welding process simulation performed in ABAQUS software indicated that the highest residual stress is concentrated on the nugget zone of the plain carbon steel side.