STEEL MATERIAL WITH EXCELLENT ROLLING FATIGUE LIFE AND METHOD OF PRODUCING THE SAME

摘要

A steel material with excellent fatigue life and method of producing the material. The material contains, in mass percent, 0.7-1.1% of C, 0.2-2.0% of Si, 0.4-2.5% of Mn, 1.6-4.0% of Cr, not less than 0.1% and less than 0.5% of Mo, 0.010-0.050% of Al, with the balance being Fe and unavoidable impurities . The material is subjected to quenching and tempering. In the material, the diameter of a grain of residual cementite is 0.05-1.5 .mu.m, and the diamete r of a grain of former austenite is not more than 30 .mu.m. Using the steel material as bearing steel can extend bearing life even under severe use conditions.