Research on the cooling rate of hot stamping
                                                            MA Yu jie1, GUO Ying ying1, MA Ning2
（1.School of mechanical and electrical engineering, Longyan University, Longyan 364000, China;2.School of Automotive Engineering and Automation, Fuzhou University, Fuzhou 350108, China）

Abstract: Aiming at the cooling rate of some complicated part of B pillar is slow and failure to completely transform to martensite which is seriously affects its mechanical properties. The hot stamping process was studied. Two optimizing designs were presented: Optimize the cooling water pipe layout to increase the cooling rate of the local mold to the plate and optimize the shape of the die surface to reduce the gap between the plate and the die. By studying the test results, the cooling rate which is the important parameters of in the hot stamping was researched. The results show that the optimization of mold cooling water piping layout has some influence on the cooling rate of hot stamping. The optimization of the die surface shape significantly improves the cooling rate of the B pillar, The gap between the die and the plate has a great influence on the cooling rate of the hot stamping.

Key words: hot stamping; cooling rate; forming process; numerical simulation