FORMATION OF STRUCTURE AND PROPERTIES OF LOCAL HARDENING ZONE DURING PLASMA HARDENING OF HYPEREUTECTOID STEELS

Abstract

Hypereutectoid steels, potentially possessing increased hardness and wear resistance under contact loading, are usually used in a heat-hardened condition (quenching and tempering) to ensure the required strength. Such heat treatment does not allow realizing the maximum hardness of the working surface of parts and is accompanied by a corresponding decrease in their service life. The solution to this problem, especially relevant for massive products such as rolling rolls, is possible using heat hardening of the working surfaces, for example, plasma hardening. In this case, the physicochemical state and properties of the material in the internal layers of the product do not change, ensuring the specified structural strength. Surface hardening of such products allows increasing their wear resistance and service life due to a favorable combination of high hardness of the surface working layer with a sufficiently strong core, the structure and properties of which are formed at previous stages of production.