| 摘要 |
A bearing part according the present invention includes, as the chemical composition, by mass%, C: 0.95% to 1.10%, Si: 0.10% to 0.70%, Mn: 0.20% to 1.20%, Cr: 0.90% to 1.60%, A1: 0.010% to 0.100%, N: 0.003% to 0.030%, P: 0.025% or less, S: 0.025% or less, O: 0.0010% or less, and optionally Mo: 0.25% or less, B: 0.0050% or less, Cu: 1.0% or less, Ni: 3.0% or less, and Ca: 0.0015% or less, and a remainder including Fe and impurities; metallographic structure includes a retained austenite, a spherical cementite and a martensite; an amount of the retained austenite is 15% to 25%, by volume%; an average grain size of prior-austenite is 8.0 µm or less; and a number density of a void having a circle equivalent diameter of 0.02 µm to 3.0 µm is 2000 mm -2 or less in the metallographic structure. |
