| 摘要 |
PROBLEM TO BE SOLVED: To provide a rolling member for a machine tool having a long service life even in a severe environment while suppressing the contents of alloy elements, and to provide a rolling bearing for the machine tool. SOLUTION: The outer ring 11, inner ring 12 and ball 13 of an angular contact ball bearing 1 supporting the main shaft of a machine tool are each composed of a steel having a composition comprising 0.7 to 1.1% carbon, 0.3 to 0.7% silicon, 0.3 to 0.8% manganese, 0.5 to 1.2% nickel, 1.3 to 1.8% chromium, 0.1 to 0.7% molybdenum and 0.2 to 0.4% vanadium, and the balance iron with impurities, and in which the content of silicon+manganese is≤1.0%, the content of nickel+chromium is≥2.3%, the content of nickel+molybdenum+vanadium is≤3.0%, a high carbon-containing layer is formed, the hardness of the surface layer part is 725 to 800 HV, the maximum grain size of carbide in the surface layer part is≤10μm, the area ratio thereof is 7 to 20%, the carbon content in the surface layer part is higher than that at the inside by 0.2 to 0.4%, and the content of nitrogen in the surface layer part is 0.1 to 0.5 mass%. COPYRIGHT: (C)2009,JPO&INPIT
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