Patent ID: 9624559
Date: 2017-04-18
CPC Classifications: C21D,C22C,F16C

Claim:
1. A bearing steel, comprising iron and, by mass percent: C: 0.95-1.10%; Si: 0.15-0.35%; Mn: 0.2-0.50%; Cr: 1.30-1.60%; P: from greater than 0 to 0.025%; S: from greater than 0 to 0.025%; Ni: 0.02-0.25%; Cu: 0.02-0.25%; Mo: from 0% to less than 0.08%; Al: 0.001%-0.050%; Ti: from greater than 0 to 0.0015%; O: from greater than 0 to 0.001%; and N: from greater than 0 to 0.020%, wherein boundary Si, boundary Mn, boundary Cr, boundary Cu, boundary Ni, and boundary Mo included in a matrix phase boundary surface region from a surface of spheroidized cementite to 20 nm away satisfies formula (1): where boundary Si, boundary Mn, boundary Cu, boundary Ni, boundary Cr, and boundary Mo represent the mass % content of Si, Mn, Cu, Ni, Cr and Mo, respectively, which are included in the matrix phase boundary surface region from the surface of spheroidized cementite to 20 nm away.