The material of the product should be considered as an integral concept that combines the substance, the technology of its production, design, technology of its manufacture and processing. The durability of products depends not only on the properties of the material, determined by the manufacturing technology and volumetric hardening, but also to a large extent on the properties of the surface. Its role in ensuring the performance properties of products is constantly increasing, which, along with the widespread use of traditional methods of chemical-thermal treatment, has contributed to the emergence and development of a new direction - surface engineering by methods of energy and physico-chemical effects. The high rate of high-frequency heating (hundreds of degrees per second) causes a shift in phase transformations to higher temperatures. Therefore, the high-frequency quenching temperature should be higher than the quenching temperature of ordinary furnace heating, and the higher the higher the heating rate. The current density across the section of the part is uneven, on the surface it is much higher than in the core. The main amount of heat is released in a thin surface layer. The depth of current penetration into the metal depends on the properties of the heated metal and is inversely proportional to the square root of the current frequency. The higher the current frequency, the thinner the resulting hardened layer. A reliable method of hardening the surface layer can give comparable results only if the quality of the surface is stable, including its cleaning. The surface condition of the part (tool) depends not only on the structure of the base material and all the conditions for its manufacture, but especially on the last operation of its production or processing. Research is being conducted, among other things, within the framework of the AP14869891 project “Increasing the operational life of heavy-loaded railway transport parts using innovative plasma technology”.

The interaction of the wheel and the rail, being the physical basis for the movement of trains, determines not only such important technical and economic indicators of railway transport as the weight of trains and their speed, the reliability and operational life of wheel sets, but also the basis of the foundations of railway operation - the safety of train traffic. Therefore, studies of the problems of interaction of the wheel-rail friction pair are relevant and in demand not only within the framework of a particular wagon or locomotive depot, but also in the country’s railway transport as a whole. In this regard, it is important to note that one of the main and most loaded elements of the undercarriage of locomotives and wagons that directly interact with the rails are railway wheels. An important factor in the development and implementation of new surface hardening technologies is: firstly, rising prices and corresponding costs for the production of metal products for wheels with high energy consumption, secondly, increasing costs for spare parts, maintenance and overhaul of wheel sets; thirdly, the rise in prices for energy carriers and transportation costs for their delivery; traditional heat treatment is almost impossible to achieve.