ROLLER OR BALL IN BEARING HAVING EXCELLENT ROLLING FATIGUE PROPERTY AND CRUSHING STRENGTH, AND BEARING

摘要

PROBLEM TO BE SOLVED: To provide a roller or a ball having an improved rolling fatigue life, and further, having improved crushing strength, and to provide a bearing using the same.;SOLUTION: In the roller or ball of a bearing using a bearing steel as the stock, the retained austenite grain size of the steel structure from the surface at least to a depth position of 1.5 mm is controlled to ≤3.5 μm. For obtaining the steel structure in a transferring section, treatment where the stock is heated to a two phase region of austenite and spheroidized carbides, is thereafter rapidly cooled, and is quenched is performed for two or more times.;COPYRIGHT: (C)2008,JPO&INPIT