Joining the combination of AHSS steel and HSLA steel by resistance spot welding

The paper deals with the optimization of parameters of resistance spot welding and quality analysis of welded joints made by combination of galvanized Advanced High Strength Steel and High Strength Low Alloy steel. It is an advanced material combination uti-lized in automotive industry to reduce weight of the vehicle body and consequently lowering the fuel consumption to achieve the lowest possible fuel consumption, high active and passive safety of passengers while decreasing the amount of emission. The quality of welded joints was evaluated by destructive tests and non-destructive tests. The shear tensile test according to STN 05 1122 standard was used. Some samples were prepared for metallographic analysis, where the influence of the welding parameters on the structure of welded joint and occurrence of pores in the weld metal caused by evaporation of zinc from the coating was observed.