Laser welding between twip steels and automotive high-strength steels

Abstract

Car-bodies are increasingly made with advanced high-strength steels in order to reduce weight and improve passenger safety. High-manganese austenitic steels have been recently proposed for such an application, due to their excellent combination of strength and toughness. However, a widespread usage of these steels in the automotive industry is conditional on the development of effective welding methods to join high-Mn steels with other steel grades employed for adjacent car-body parts. Therefore, dissimilar laser welding, without any filler metal, between a high-Mn austenitic sheet steel and some high strength steel grades, frequently employed in the fabrication of car body parts, are examined here. The weldments are characterized by means of metallography, tensile and microhardness tests. Fractographic examination was carried out on the fracture surfaces of the tensile samples