Abstract
This paper proposes two-stage hardening modes for U11, 9XVG, and XGS steels. In this case, the first hardening is performed with heating above Ac3, and the second hardening with heating above Ac1s. Such heat treatment ensures the production of dispersed secondary carbides, and the service life of the product increases by 3-4 times. It is shown that a high level of defectiveness of the crystalline structure of hardened steel is achieved only after heating to 1000-1200 °C. In this case, the austenite grain grows sharply. Repeated heat treatment using conventional technology ensures not only crushing of the austenite grain, but also inheritance of an increased level of defectiveness of the crystalline structure. Due to this, wear resistance increases. An increase in wear resistance is possible from 20-25% to 2 times or more. Similar heat treatment modes (double hardening, when the first hardening is high-temperature) can provide an increase in the crack propagation resistance of steel.