| abstract |
Disclosed is a deep groove ball bearing (1) comprising, as its machine components, an outer wheel (11), an inner wheel (12) and a ball (13). Each of the outer wheel (11), the inner wheel (12) and the ball (13) comprises a steel which comprises 0.77 to 0.85% of carbon, 0.01 to 0.25% of silicon, 0.01 to 0.35% of manganese, 0.01 to 0.15% of nickel, 3.75 to 4.25% of chromium, 4 to 4.5% of molybdenum and 0.9 to 1.1% of vanadium, with the remainder being iron and unavoidable impurities. In an area having a rolling surface (11A, 12A, 13A) therein, a nitrogen-rich layer (11B, 12B, 13B) having a nitrogen content of 0.05 mass% or more is formed. The sum total of the carbon content and the nitrogen content in the nitrogen-rich layer (11B, 12B, 13B) is 0.82 to 1.9 mass% inclusive. |