Optimal parameters for laser welding of advanced high-strength steels used in the automotive industry

Laser welding process depends on several parameters that deeply influence the final result. Thus, it is important to determine how these parameters influence the welding. The aim of this work is to determine the optimal laser welding parameters of a dual-phase steel, more specifically the DP600. In order to accomplish this objective, small sheets were welded in the flat position with a butt joint, using a laser Nd:YAG welding machine SISMA SWA300. Thus, in this work, the weldability of this steel is assessed by determining the optimal parameters to weld it with a pulsed laser. In order to evaluate the welded samples, tensile and microhardness tests were performed. In addition, a heat treatment was carried out in order to reduce the hardness of the heat affected zone. In conclusion, with the optimal parameters, it is possible to successfully weld a dual-phase steel with laser technology, more specifically the DP600.