BEARING MEMBER EXCELLENT IN HEAT TREATING PRODUCTIVITY AND DELAYING CHARACTERISTIC IN CHANGE OF MICROSTRUCTURE DUE TO REPEATED STRESS LOAD

摘要

PURPOSE: To produce a bearing steel small in the change of the microstructure due to repeated stress loads and having a long bearing service life even under severe using conditions not only in a clean environment but also under severe use conditions in which dust is contained in high heat treatment productivity. ;CONSTITUTION: The componental compsn. contg., for improving heat treating productivity, by weight, 0.001 to 0.015% Sb, furthermore, for promoting the delay in the change of the microstructure due to repeated stress loads, particularly contg. 1.0 to 2.5% Cu as B₅₀ high load rolling fatigue life improving components and contg. one or ≥ two kinds selected from among 0.5 to 2.5% Si, 2.0 to 5.0%Mn, 2.5 to 8.0% Cr, 0.5 to 2.0% Mo, 1.0 to 3.0% Ni, 1.0 to 2.5% Cu, 0.012 to 0.050% N, 0.05 to 1.0% v, 0.05 to 1.0% Nb, 0.05 to 1.0% W, 0.02 to 0.5% Zr, 0.02 to 0.5% Ta, 0.02 to 0.5% Hf and 0.05 to 1.5% Co is formed. Furthermore, the amt. of retained austenite occupies 10 to 35% in the structure.;COPYRIGHT: (C)1995,JPO