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|1. (WO2017154652) STEEL MATERIAL FOR BEARING HAVING EXCELLENT ROLLING FATIGUE CHARACTERISTICS, METHOD FOR MANUFACTURING SAME, AND BEARING COMPONENT|
|Applicants:||KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.)
|Title:||STEEL MATERIAL FOR BEARING HAVING EXCELLENT ROLLING FATIGUE CHARACTERISTICS, METHOD FOR MANUFACTURING SAME, AND BEARING COMPONENT|
This steel material for a bearing comprises a steel component containing C, Si, Mn, Cr, P, S, Al, Ti, N, and O, the remainder being iron and unavoidable impurities, oxide-based inclusions having a minor axis of 1 µm or greater which are present in the steel material containing Al2O3, SiO2, and TiO2, the remainder comprising unavoidable impurities, the total percentage by mass of Al2O3, SiO2, and TiO2 being 60% or greater, the mass ratio of TiO2 with respect to the total mass of Al2O3 and SiO2 being 0.10 to 1.50, and the percentage of composite inclusions in which TiN is present at the interface with a parent phase of the steel material among the oxide-based inclusions with respect to the total number of oxide-based inclusions being 30% or greater.