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.
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/μm2, the average grain size of old austenite grains after quenching is controlled to ≤3.5 μm, 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/μm2is heated at an Ac3point or above to an Ac3point+≤130°C or below in such a manner that the average heating rate in the temperature range from an Ac3point-10°C to an Ac3point is controlled to ≥0.5°C/s, and holding time at an Ac3point or above is controlled to ≤500 s so as to be subjected to quenching treatment.
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