Influence of Technological Heredity on the Process of Ion-Plasma Nitriding in the Glow Discharge of Tool Steel R6m5

This paper presents the results of determining the effect of preliminary polishing on the structure and depth of the hardened layer after ion nitriding in the glow discharge. Dry electropolishing of the surface of high-speed steel P6M5 with subsequent ion nitriding in the glow discharge contributes to the intensification of diffusion processes and, as a consequence, an increase in the thickness of the diffusion layer with a decrease in the nitride zone due to increased adsorption activity of the surface. Measurement of microhardness showed that pre-polishing allows obtaining more uniform profile of microhardness distribution along the depth of the surface layer due to increased diffusion of nitrogen into the core of the sample. The application of dry electropolishing of the surface of high-speed steel P6M5 before ion nitriding in the glow discharge has prospects for application in the tool industry as an independent method of surface hardening and as a pretreatment before deposition of wear-resistant coating because it allows obtaining on the treated surface of a hardened layer with a smoother hardness gradient.