Induction assisted laser welding of advanced high strength steels to increase the formability of welded automotive body structures Available to Purchase

Advanced high-strength multi phase steels are currently approaching to practical application in the automotive body industry. The outstanding mechanical properties of these materials, e.g. high strength and excellent formability, base on their multi phase structure. Due to high productivity and low heat input, laser welding is a profitable production procedure for joining these materials in semi-finished production and in body in white manufacturing. But the enhanced content of alloying elements of high strength multi phase steels causes an increased seam hardness which results in a reduced ductility within the weld metal and the HAZ and leads to a severely restricted formability of the welded structure. In order to improve the mechanical properties of the welded joint several strategies of induction assisted laser welding have been investigated. The optimized welding procedure realizes a hardness reduction and a significant increase of ductility. This makes the adjustment of the weld seam formability possible and improves the joint properties adapted to the functional requirements. The formability of laser-induction welded structures of various materials have been discovered by determination of forming limit curves. Different preformed material states have been investigated too, in order to determine the influence of work hardening effects. The results enable the assessment of the forming behavior of complex welded components as well as the estimation of the material performance in case of crash.