| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel material which is a bearing material used for roller bearing such as ball bearing and enables high-precision and high-efficiency grinding at the final grinding of rolling elements and to contribute to the improvement of the productivity and performance of a bearing. SOLUTION: This bearing steel excellent in grindability has a composition consisting of, by weight, 0.6-1.2% C, 0.1-2.0% Si, 0.1-2.0% Mn, 0.8-14.0% Cr and the valance Fe with inevitable impurities. Moreover, the relationship between the length, in a rolling direction, of carbonitrides composed essentially of Ti existing as the inevitable impurities and the number of these carbonitrides, with respect to 200 mm2 inspection area, is as follows: the number of the carbonitrides with a length of 10-<25μm is n1; the number of those with a length of 25-<50μm is n2; the number of those with a length of 50-<75μm is n3; and the number of those with a length of >=75μm is n4. Further, when an inclusion index N is represented by N=2n1+5n2+10n3+15n4, 10<=N<=80 is satisfied.
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