Patent ID: 8591673

Claim:
An antifriction bearing comprising: an inner ring; an outer ring; and a rolling element, wherein at least one of the inner ring, the outer ring, and the rolling element is made of a martensitic stainless steel consisting essentially of, by weight %, 0.35 to 0.45% of C, less than 0.2% of Si, not more than 0.3% of Mn, not more than 0.02% of P, not more than 0.02% of S, 15 to 17% of Cr, 1.5 to 2.5% of Mo, 0.001 to 0.003% of B, 0.015 to 0.25% of N, 0.1 to 0.2% of W, and the balance of Fe and inevitable impurities, wherein BN is precipitated but M 23 C 6 type Carbide is not precipitated in the martensitic stainless steel.