Features of Structural–Phase Changes and Tribological Behavior of Tool Steel After Vacuum and Plasma Electrolytic Nitriding

Nitriding is one of the technologies used to improve the performance properties of tool steels. In addition to traditional gas nitriding, technologies aimed at increasing the productivity and/or efficiency of processing have found application in industry. This paper presents the results of using vacuum and plasma electrolytic nitriding to improve the wear resistance of M2 high-speed steel, as well as prospects for further development of these technologies. XRD and SEM methods were used to study the structural and phase changes in the surface layers, showing the formation of layers of connections hardened to 1200–1300 HV. Tribological tests were carried out under dry friction conditions according to the shaft-shoe scheme with varying sliding speed. The mechanism of contact interaction during the friction of nitrided steel was established. It is shown that plastic deformations are the prevailing type of deformation. The mechanism of destruction of the surface layer is fatigue wear during dry friction without lubrication. This provides an increase in wear resistance by 6–29 times.