Heating Parameters Optimization of Hot Stamping by Partition Heating for Tailored Properties

抄録

In this paper, a new hot stamping process of boron steel by using partition heating was adopted to produce the components with tailored properties for a better crash response. A hot stamping simulation experiment was performed using a furnace and a flat die to investigate the effect of heating temperature and heating time on the mechanical and microstructural properties of as-quenched boron steel. Response surface models reflecting the relationship of tensile strength and elongation with heating temperature and heating time in both high and low temperature regions are established and analyzed. Multi-objective optimization is performed by using non-dominated sorting genetic algorithm II (NSGA-II) to obtain the optimal frontiers, and the optimal heating parameters are selected according different demands for mechanical properties in high and low temperature regions. The M-shaped part with tailored properties was hot stamped using partition heating according to optimal heating parameters, whose tensile strengths and elongations are 1572 MPa and 9.41% in high-temperature region and 554 MPa and 26.73% in low-temperature region, respectively.