Combined Thermochemical Treatment of High-Chromium Bearing Steels

Abstract—The influence of combined thermochemical treatment consisting of preliminary vacuum nitriding, subsequent vacuum carbonitriding, and final heat treatment (quenching from repeated heating + subzero treatment at –78°C + low tempering) on the wear resistance of high-chromium martensitic bearing steels (95Kh18-Sh, 110Kh18M-ShD) is studied. The combined treatment is shown to increase the contact fatigue limit to 4900 MPa at a specific wear rate no more than (1.05–1.29) ×10^–5 mm³/(N m). Preliminary nitriding is found to positively affect wear resistance and fatigue limit, and subzero treatment negatively affects these characteristics.