The bearing steel which is superior in convolution fatigue life quality, the ingot-making material and those production methods null for the bearing

摘要

PROBLEM TO BE SOLVED: To provide a method for suppressing production of eutectic carbide in a segregated zone, even in a bearing steel derived from an ingot material as well as that derived from a continuously cast material.;SOLUTION: The bearing steel has a component composition which comprises 0.56 to 0.70 mass% C, 0.15 mass% or more but less than 0.50 mass% Si, 0.60 to 1.50 mass% Mn, 0.50 to 1.10 mass% Cr, 0.05 to 0.5 mass% Mo, 0.025 mass% or less P, 0.025 mass% or less S, 0.005 to 0.500 mass% Al, 0.0015 mass% or less O, 0.0030 to 0.015 mass% N and the balance being Fe and inevitable impurities, and which has an eutectic carbide generation index Ec that is 0Ec≤0.25 and an Mo segregation degree that is 2.8 or less.;COPYRIGHT: (C)2012,JPO&INPIT