Failure mode prediction of resistance spot welded quenching and partitioning stainless steel

This paper presents an experimental and numerical study, carried out in order to develop knowledge about the assembly mechanical behavior of two spot-welded austenitic stainless steel (AISI 304) sheets. The assembly is subjected to a quasi-static tensile loading. Thus, the surface response methodology is used to evaluate the effects of the main welding parameters for an optimal improvement of the weldment mechanical strength. Regression analysis (statistical optimization) was applied to evaluate the behavior of welded joints under different stresses, necessary to predict the optimal parameters of the welding process, and to quantify the impact of various types of loading on welded joint damage. Using the desirability function, with a maximum of 98%, optimal multi-objective analysis predicted the optimal parameters (I, D and t) leading to maximum tensile-shear and tensile-peel of the weldment. The developed FEM proved to be effective in characterizing the tensile strength and deducing the type of damage to the spot-welded structure. This study makes it possible to meet several industrial requirements in order to improve the impact resistance of light vehicles.