| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rolling bearing capable of controlling any acoustic degradation and prolonging the acoustic lifetime by using a material in which the surface roughness is hardly degraded. <P>SOLUTION: At least any one of outer and inner rings, and a rolling element is formed of steel containing, 0.3-1.2 mass% C, 0.3-2.2 mass% Si and 0.3-2.0 mass% Mn. Bearing steel is used, in which the nitrogen concentration of a surface of a rolling surface is 0.2-2.0 mass% through the carbonitriding treatment or the nitriding treatment, and the area ratio of nitride containing Si and Mn is ≥1% and <20%, while the inequalities γrAB-15≤γrC≤γrAB+15, 0≤γrAB, and γrC≤50 are satisfied, where γrAB denotes the amount of residual austenite of the surfaces of the inner and outer ring raceway surfaces, and γrC denotes the amount of residual austenite of the rolling surface of the rolling element. Further, the kinematic viscosity of the base oil of grease at 40-70°C is 10-30 mm<SP POS="POST">2</SP>/s. <P>COPYRIGHT: (C)2013,JPO&INPIT |
