Patent ID: 6537390
Filing Date: 2003-03-25
Classification: F16C,Y10S

Abstract:
An antifriction bearing comprising bearing rings and rolling members which are made from a steel material containing 0.15 to 0.3 wt. % of carbon by being subjected to heat treatments including carburizing, a surface layer of raceway surface of each of the bearing rings and a surface layer of rolling surface of each of the rolling members being 1.0 to 1.5 wt. % in carbon content, 64 to 66 in Rockwell hardness C, 150 to 2000 MPa in compressive residual stress, up to 3 &mgr;m in maximum carbide particle size and 10 to 25% in carbide area ratio, at a depth of 0 to 50 &mgr;m as measured from the outermost surface of the surface layer, the surface layers being 0.75 to 1.3 wt. % in carbon content, 150 to 1000 MPa in compressive residual stress, 25 to 45% in residual austenite content, up to 1 &mgr;m in maximum carbide particle size and up to 15% in carbide area ratio, at a depth of 50 to a/5 &mgr;m, wherein a is the effective case depth in &mgr;m, as measured from the outermost surface of the surface layer.