Investigation on mechanical properties distribution on hot stamped part

Abstract

A M-shaped part is a typical section in advanced high strength steel components such as side impacts, bumper beams and bpillar. In this paper, an M-shaped part has been hot stamped. To research the microstructure and mechanical properties distribution of the M-shaped part, tensile tests of hot stamped samples were performed. The mechanical properties vary in different regions of the M-shaped part. To explain this difference and to predict the properties distribution, a 2D thermomechanical finite element (FE) model based on the Johnson Cook constitutive equation, was developed to simulate the hot stamping process for the M-shaped part. Based on the FE results, the cooling rates in die-quenching stage changes along the Mshaped section because of different tools' gap and holding pressure, which causes the fluctuation of microstructure and mechanical properties.