| 摘要 |
PROBLEM TO BE SOLVED: To provide a roller bearing which can be manufactured at a low cost without employing a special material or a special heat treatment by appropriately regulating hardness in each portion of respective rollers 3 and 3, an amount of retained austenite and a value of a compression residual stress in a predetermined portion, which cause the increase of the cost, and besides, can show superior performance including durability. SOLUTION: A value X of the harnesses in the core portion of each of the rollers 3 and 3 shall be at 770 to 830 Hv by Vickers hardness. A value of hardnesses on the surface of each of the rollers 3 and 3 shall be represented by Y. Then, the hardnesses satisfy 1.006×X≤Y≤1.050×X. In addition, the amount of retained austenite in the core portion of each of the rollers 3 and 3 shall be 15 to 25 vol.%. Furthermore, the maximum value of the compression residual stress at a depth of 50μm from the surface of each of the rollers 3 and 3 shall be 300 to 900 MPa. COPYRIGHT: (C)2009,JPO&INPIT
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