Rolling bearing made of improved bearing steel
AssigneeNsk Ltd.
InventorsYasuo Murakami, Nobuaki Mitamura, Seiji Sato
Life of this patent
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Abstract
A bearing steel includes 0.70 to 0.93 wt % of C, 0.15 to 0.50 wt % of Si, 0.50 to 1.10 wt % of Mn and 0.3 to 0.65 wt % of Cr, with the balance being Fe and incidental impurities, and it has the ratio Cr/C specified to fall within 0.4 to 0.7. Because of these compositional features, the generation of macro carbides is prevented and the need to perform soaking at high temperature for a prolonged time is eliminated. Further, the bearing steel saves the materials cost and the overall cost of heat treatments in the manufacture of bearings and which yet is capable of satisfying the requirements of various characteristics of bearings, as well as a rolling bearing that employs the bearing steel.
Claims2
A rolling bearing comprising component parts of an inner race, an outer race and a plurality of rolling elements, at least one of the component parts being made of a bearing steel comprising:
- 0.70 to 0.93 wt % of C;
- 0.15 to 0.50 wt % of Si;
- 0.50 to 1.10 wt % of Mn;
- 0. 3 to 0.65 wt % of Cr;
- and
- the balance being Fe,
- wherein the one of the component parts satisfies a relationship of 0.4.ltoreq.Cr/C.ltoreq.0.7 to thereby avoid generation of eutectic carbides.
Dependencies are inferred from the claim text.