To provide a rolling bearing which does not have a tendency to cause internal start rupture and has a long service life, and to provide a method of manufacturing the rolling bearing.
The inner ring 1, the outer ring 2, and the rolling elements 3 of a cylindrical roller bearing are made of bearing steel such as SUJ2. Heat treatment including induction hardening is applied to the inner ring 1 and the outer ring 2, and a hard layer hardened by the heat treatment is formed on each of raceway surfaces 1a, 2a. The hardness of the hardened layer exceeds Hv600, and the hardness of an un-hardened core in the hardened layer is equal to or lower than Hv600. The heat treatment including the induction hardening is performed in such a manner that the hardness gradient of the boundary area between the hardened layer and the core is gentle. Namely, the value of the hardness gradient of the boundary area between the portion of the hardened layer which has a hardness of Hv650 and the portion of the core which has a hardness of Hv300 in the depth direction obtained by a least-square method is equal to or lower than 89. Consequently, the hardness gradient is gentler than the gradient of stress acting thereon.
WATANUKI DAISUKE
| JP2002004003A | 2002-01-09 | |||
| JPS57174414A | 1982-10-27 | |||
| JP2007277728A | 2007-10-25 | |||
| JPH07224627A | 1995-08-22 |
Yoshiaki Naito
Cui Shu Tetsu