Investigation of the clinching process combines with hot stamping process for high-strength steel sheets

Abstract

The mechanical clinching process combining with hot stamping process for high-strength steel sheets is investigated in this study. Finite elements analysis method and experimental method are applied to analyse the formation of high-strength steel sheet. The connecting strength between two sheets is discussed via the relation between neck thickness and undercut, and the Vickers hardness. The results indicated that the cooling water channels of hot stamping die provided efficiently temperature exchange to control the temperature of sheets. The 15B22 sheet, after being hot stamping process, obtained higher connecting strength than S15C and S45C. At high temperature, the materials properties of 15B22 are similar to that of the S15C. However, due to the hardness of 15B22 is higher than that of S15C and S45C, the undercut is also higher. Hot stamping process means to rapid cooling hot metal, which change the structure from austenite to martensite, so that the hardness will be increased. Hence, the connecting strength of 15B22 is stronger than S15C and S45C.