Rolling elements for rolling bearings and rolling bearings using the same

Abstract

The present invention provides rolling bearing components (rolling elements) and rolling bearings using them that can dramatically improve the indentation resistance required for rolling bearings. [Solution] The rolling elements for a rolling bearing are made of alloy steel containing, by mass%, C: 0.40~0.95%, Si: 0.70~2.50%, Mn: 0.10~1.00%, Cr: 1.00~4.00%, W+2Mo: 0.40~3.00%, V: 0.05~0.80%, with the remainder being iron and unavoidable impurities. The rolling elements for the rolling bearing have a carburized and nitrided layer with a thickness of 300 μm or more on the raceway surface, and the amount of retained austenite on the raceway surface is in the range of 15 volume% to 30 volume%.

Claims

1. A rolling element for a rolling bearing, made of alloy steel containing, by mass%, C: 0.40-0.95%, Si: 0.70-2.50%, Mn: 0.10-1.00%, Cr: 1.00-4.00%, W+2Mo: 0.40-3.00%, V: 0.05-0.80%, with the remainder being iron and unavoidable impurities, wherein the rolling element for a rolling bearing has a carburized and nitrided layer with a thickness of 300 μm or more on the raceway surface, and has been quenched and tempered, with the amount of retained austenite on the raceway surface being 15 volume% to 30 volume%.

2. The rolling element for a rolling bearing according to claim 1, characterized in that the hardness of the carburized and nitrided layer is 800 HV or more on a Vickers hardness scale, and the hardness of the alloy steel directly beneath the carburized and nitrided layer is 760 HV or more on a Vickers hardness scale.

3. A rolling bearing characterized by comprising rolling elements for a rolling bearing as described in claim 1 or 2.

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