Carburized bearing steel parts and steel bars for carburized bearing steel parts

摘要

A carburized bearing steel part has a predetermined chemical composition, and, in the carburized bearing steel part, the number density of oxide particles having an equivalent circle diameter of 5 μm or more, and containing CaO, Al2O3 and SiO2, such that the content ratio of Al2O3 with respect to the total mass of CaO, Al2O3, and SiO2 is 50% by mass or more, is 3.0/cm2 or less in an arbitrary cross section of the part, the Vickers hardness at a depth of 50 μm from a rolling surface is 750 or more, and the compressive residual stress at the rolling surface is 900 MPa or more. Also provided is a steel bar for a carburized bearing steel part that is suitable for obtaining the foregoing carburized bearing steel part.