Patent ID: 7763124

Claim:
A steel having excellent rolling contact fatigue life, consisting essentially of 0.7 to 1.1% C, 0.61 to 2.0% Si, 0.4 to 2.5% Mn, 3.5 to 4.0% Cr, 0.33% or more and less than 0.5% Mo, 0.010 to 0.050% Al, by mass, optionally at least one element selected from the group consisting of 0.5 to 2.0% Ni, 0.05 to 1.00% V, 0.005 to 0.50% Nb and 0.0010 to 0.0050% Sb, by mass and a balance of Fe and inevitable impurities; having a martensite-based microstructure caused by quenching and tempering; and having residual cementite grains of an average grain size ranging from 0.05 to 1.5 μm, and prior-austenite grains of an average grain size of 30 μm or smaller.