Methods of eliminating defects arising in the chemicothermal and thermal processing of chrome—nickel steel components

Abstract

Chrome—nickel steel 20Kh2N4A is used in bearing production, particularly for large bearings, which contains 0.16–0.22% C, 3.25–3.65% Ni, and 1.25–1.65% Cr, with the other elements in the usual ranges for electrosteel, and which is used with deep case hardening. In spite of much research, no steel equivalent in properties to 20Kh2N4A has been discovered for use with case hardening by chemicothennal treatment. The successful combination of chromium and nickel in 20Kh2N4A provides the best mechanical properties. Components operating with elevated frictional wear and high shock loads are made from that steel. However, the high chromium and nickel contents complicate technological operations and sometimes cause a specific form of rejection, which is most prominent on prolonged case hardening with case-hardened layers thicker than 2 mm.