Welding investigations of modern high strength dual phase and TRIP - Steel for Automotive Industry application

Abstract

Year by year the user and process site of steelmarket keep growing and lay claim to the steelmakers. The researchers, developers and technologists use every effort to try to produce steels with compound properties. From claim of users - especially the Automotive Industry - developed the DP- (Dual Phase) and TRIP - steels (TRansformation Induced Placticity). In the Automotive Industry draft mostly the claim of loose of weight and increase the safety reserve.Welding of these Advanced High Strenght Steels (AHSS does have but very few publications and studies approach the subject). This study is about problems of weldability of Dual Phase and TRIP - steels. Welding difficulties were associated with hard and brittle spot weld nuggets and fusion weld heat affected zones being caused by nitrid. Our aim is to develop a welding procedure giving good quality of spot weld, thus the problem of hardened and brittle spot welds would cease to exist.