Wear Properties of High-Hardness Tool Steel by Directed Energy Deposition Based Additive Manufacturing

Abstract

Recently, with the increase in the application of UHSS plates in automobiles, the service life of existing molds is being shortened, and directed energy deposited type 3D printing technology is being considered as a way to extend the service life. In this study, in order to improve the service life of cold molds, the wear characteristics of the deposited parts using composition systems were analysed, and the possibility of practical application was estimated through evaluation with shear molds.</br>Since the high hardness of AM layer can be reached without additional heat treatment, it was expected to improve the service life when applied to the surface of the mold. Through the wear evaluation of the ball-on-disk method, it was confirmed the wear performance improvement of M4, and as a result of the shear mold life evaluation of 1.5 GPa class high-strength automotive steel plate for the M4 deposited, it was found that shear up to 17,000 strokes were possible. When the number of strokes was increased, a fracture layer due to deposition was observed in the cross-section of the mold surface, and it is believed that additional heat treatment research is required to improve the life of the AM mold.