New insights into the fracture behavior of advanced high strength steel resistance spot welds

While the automotive industry is striving for reduction of car body weight to increase fuel efficiency and reduce CO2 emission without compromising safety crashworthiness vehicles, a new generation advanced high strength steels (AHSS) have emerged as excellent candidates meet these requirements. However, their integration into structure associated with welding-related problems. This research utilizes novel approach establish fundamental correlation between welding parameters, microstructure mechanical performance AHSS resistance spot welds. In-situ micro-cantilever bending experiments are executed analyzed in quantitative manner evaluate effect texture post-welding heat treatment on local fracture toughness A striking finding that, through switch from single double pulse weld scheme, martensite formed fusion zone becomes responsible significantly higher area front pre-crack. In addition, it found that paint baking also results much enhanced tempering martensitic microstructure. made micro-scale macro-scale steel