The Process Optimization to Prevent the Local Wrinkles of Hot Stamping Parts and the Design of Tools

Abstract

During the process of hot stamping, due to the deformations of sheet metals are mainly bending and shallow drawing, as well as to prevent the temperature strikingly drop caused by the local contact of sheet metal and die, the hot stamping tool usually does not set up blank-holder. And this leads to the occurrence of local wrinkles in some types of hot stamping parts, which affect the quality of the parts. Through the hot stamping tool design and process test of a car ́s B pillar, it discovered that the local wrinkle in the part ́s big end is more severe. As a result the program was modified by taking advantage of the forming principle of the counter punch to improve the design of upper tool (die), which eliminated the local wrinkle in the big end and improved the contact cooling efficiency, consequently ensured the hot forming parts ́ quality and reduced the production rhythm.