Sliding Damage Evaluation of Coatings for Press Forming Die

Abstract

In this study, we developed a basic test method of reproducing the slide damage of surface coating layers on dies during actual press working. To simulate actual production processes, dies made of SKD11 on which TiC, TiN, CrN, or VC was coated by PVD, CVD or TRD were used. The sliding damage of the coatings was quantitatively evaluated by this new method, and results showed good agreement with the results of the X-ray diffraction technique and surface roughness measurement. In the case of galvanized blank steel sheets, it was found that the surface damage was caused by the adhesion of zinc onto the coated die. Excellent resistance against the sliding damage was obtained for the VC coating layer by TRD.