Optimal Design for Cooling System of Hot Stamping Dies

In recent years, hot-stamped components with advanced high strength have been more and more widely used in car body manufacturing for the advantageous properties such as high strength-to-weight ratio and good crash behavior, which enable the possibility of weight reduction and enhancing passenger safety at the same time.1–3) In the production of hot-stamped components, the initial blank with ferritic-perlitic microstructure is heated to completely austenitic state firstly, and then formed and quenched in the closed dies.4,5) The rapid cooling in the hot stamping dies results in the transformation from austenite to martensite. The martensitic microstructure provides the final part with an ultra high strength up to 1 500 MPa.6) To achieve rapid cooling, a cooling system is essential to be integrated into the hot stamping dies. Cooling system design of the hot stamping dies significantly influences not only the cooling performance of the dies and the properties of the final part, but the production efficiency and the service life of the dies as well. To improve the cooling performance of the hot stamping dies, several studies have been conducted. Steinbeiss et al.7) presented a specific evolutionary algorithm to design the hot stamping Optimal Design for Cooling System of Hot Stamping Dies