Patent ID: 9139887
Filing Date: 2015-09-22
Classification: C21D,C22C

Abstract:
1. Bearing steel, comprising a chemical composition including by mass %, C: 0.56% to 0.70%, inclusive of 0.56% and 0.70%, Si: 0.15% to 0.50%, inclusive of 0.15% and exclusive of 0.50%, Mn: 0.60% to 1.50%, inclusive of 0.60% and 1.50%, Cr: 0.50% to 1.10%, inclusive of 0.50% and 1.10%, Mo: 0.05% to 0.5%, inclusive of 0.05% and 0.5%, P: 0.025% or less, S: 0.025% or less, Al: 0.005% to 0.500%, inclusive of 0.005% and 0.500%, O: 0.0015% or less, N: 0.0030% to 0.015%, inclusive of 0.0030% and 0.015%, and remainder as Fe and incidental impurities, wherein “eutectic carbide formation index Ec” represented by following formula (1) is in the range of 0.04=<Ec≦0.23 and “degree of segregation” represented by following formula (2) is equal to or less than 2.8 in the bearing steel, in formulae (1) and (2), “[% M]” represents content (mass %) of component M and C