Analysis of high temperature tensile properties of multi material matching laser tailor welded joints

In recent years, hot formed steel has been widely introduced into the automotive industry and has become an important part of automotive lightweight solutions. In order to meet the safety and energy absorption requirements of collision regulations, improved hot formed technologies such as laser tailor welding technology have been applied. HC340LA and HC340/590DP were used for laser tailor welding with 22MnB5 respectively, and high temperature tensile properties of each material were determined through high temperature tensile test, constitutive equation for simulation analysis was obtained by fitting calculation. By analyzing high temperature tensile fracture elongation and high temperature tensile strength, advantages and disadvantages of high temperature forming characteristics of materials were simply and quickly evaluated, so as to determine process feasibility of multi intensity gradient laser tailor welding hot forming, and two high-low matching hot forming combination schemes of 450 MPa, 600 MPa and 1 500 MPa were obtained.Highlights: By analyzing high temperature tensile fracture elongation and high temperature tensile strength, high temperature forming characteristics of materials were simply and quickly evaluated, and high temperature forming characteristics of dissimilar materials containing hot formed steel were revealed.