| 摘要 |
PROBLEM TO BE SOLVED: To provide a component for a bearing having improved fatigue properties by fining the old austenite grain size in the surface layer part, and subjected to quenching treatment suitable for a bearing, inner and outer races of the bearing, a bearing ball or the like, and to provide a method for producing the same. SOLUTION: Regarding the steel component for a bearing, in the surface layer, the number of spheroidized carbides in the former structure before quenching is controlled to≥1.15 pieces/μm<SP>2</SP>, the average grain size of old austenite grains after quenching is controlled to≤3.5μm, and, the steel component preferably has a componential composition comprising, by mass, 0.6 to 1.5% C, 0.1 to 1.0% Si, 0.1 to 1.5% Mn,≤0.1% Al and 0.05 to 2.0% Cr, and, when needed, one or more selected from Cu, Ni, Mo, W, Ti, Nb, B, Sb and N are added thereto. A steel in which the number of spheroidized carbides per unit area is≥1.15 pieces/μm<SP>2</SP>is heated at an Ac<SB>3</SB>point or above to an Ac<SB>3</SB>point+≤130°C or below in such a manner that the average heating rate in the temperature range from an Ac<SB>3</SB>point-10°C to an Ac<SB>3</SB>point is controlled to≥0.5°C/s, and holding time at an Ac<SB>3</SB>point or above is controlled to≤500 s so as to be subjected to quenching treatment. COPYRIGHT: (C)2007,JPO&INPIT |
