Rolling bearing

摘要

A rolling bearing in which at least one of the bearing rings is obtained by applying a induction heat treatment to a spheroidizing annealed steel material having a DI value of 1.0 or more to form a hardened layer having a hardness of 550 HV or more on at least a raceway surface and a fitting surface. In the induction heat-treated bearing ring, (A) an average retained austenite amount is 12 vol % or less, (B) the raceway surface has a retained austenite amount of 12 vol % or more and a residual compressive stress of −100 MPa or less, and (C) a difference between a hardness of the raceway surface and a minimum hardness of a region having a hardness of less than 550 HV is 150 HV or more.

主权项

1. A rolling bearing comprising one or more parts of a pair of bearing rings and a rolling element, wherein:
at least one of the bearing rings is obtained by applying a induction heat treatment to a spheroidizing annealed steel material having a DI value represented by the following formula (1) of 1.0 or more to form a hardened layer having a hardness of 550 HV or more on at least a raceway surface and a fitting surface, and in the induction heat-treated bearing ring, the raceway surface has a retained austenite amount of 12 vol % or more, and a difference between a hardness of the raceway surface and a minimum hardness of a region having a hardness of less than 550 HV is 150 HV or more,
DI=D0×fSi×fMn×fNi×fCr×fMo  (1) D0=0.2×(C)+0.14 fSi=1+0.64×(Si) fMn=1+4.1×(Mn) fNi=1+0.52×(Ni) fCr=1+2.33×(Cr) fMo=1+3.14×(Mo) where (C), (Si), (Mn), (Ni), (Cr) and (Mo) are contents (mass %) of respective elements in the steel material.