Study on Deformablity and Material Flowing Behavior of Tailor-Welded Blanks of Dissimilar High-strength Steel

Abstract In this study, tensile and cupping tests were carried out aimed at dissimilar high-strength steel laser tailor-welded blanks(TWBs) of DP590-TRIP590 and DP590-HC420, in order to study deformation ability and material flow rule. The influence of welding position on cupping performance was also analyzed. Results indicate that the welding seam and its location have a significant effect on the deformation capacity of the TWBs. The tensile properties of TWBs are primarily governed by the weaker base metal, and TWBs tensile strength is close to the weaker base metal. The DP590-TRIP590 TWBs(x=0) exhibit the highest ductility compared to those with other welding positions. The fracture occurs randomly on each side of TWBs(x=0 and ±8), whereas all fractures happen on the base metal with a larger proportion for TWBs(x=±16). For DP590-HC420 TWBs, the overall ductility is governed by the proportion of HC420. Fracture always occurs on the HC420 base metal, in which side material flow is more pronounced.