Patent ID: 8596875

Claim:
A bearing constituent member obtained from a steel comprising 3.2 to 5.0% by mass of chromium and 0.05% by mass or more to less than 0.5% by mass of vanadium and having a polish-finished surface, the bearing constituent member comprising: a surface layer, wherein the content of carbon in the surface layer ranging from a surface of the surface layer to a depth of 10 μm is 1.1 to 1.6% by mass, wherein Vickers hardness at a position of a depth of 50 μm from the surface is 740 to 900, wherein the amount of residual austenite at a position of a depth of 10 μm from the surface is 20 to 55% by volume, wherein the content of nitrogen in the surface layer ranging from the surface to a depth of 10 μm is 0.1 to 1.0% by mass, and wherein at least one of particles composed of vanadium nitride having a particle diameter of 0.2 to 2 μm and particles composed of vanadium carbonitride having a particle diameter of 0.2 to 2 μm are present in the surface layer ranging from the surface to a depth of 10 μm and at least one of the area ratio of the particles composed of vanadium nitride having a particle diameter of 0.2 to 2 μm and the particles composed of vanadium carbonitride having a particle diameter of 0.2 to 2 μm in the surface layer ranging from the surface to a depth of 10 μm is 1 to 10%.