| 摘要 |
PROBLEM TO BE SOLVED: To provide a machine part, a roller bearing, and a method for manufacturing the machine part, which enable both improvements in durability and dimensional stability of the machine part to be achieved.SOLUTION: An outer ring 11, an inner ring 12, and a ball 13 which are machine parts, are made of a steel which comprises carbon of 0.60 to 1.50 mass%, silicon of 0.15 to 2.50 mass%, manganese of 0.30 to 1.50 mass%, chrome of 0.20 to 2.00 mass%, and the balance impurities. Nitrogen densities in surface layer parts 11B, 12B, and 13B below an outer ring rolling surface 11A, an inner ring rolling surface 12A, and a ball rolling surface 13A which are contact surfaces in contact with other parts, are 0.3 mass% or more, and an overall average contents of retained austenite in the outer ring 11, the inner ring 12 and the ball 13 are each 20 vol% or less. |
