Rolling contact fatigue characteristics of newly developed bearing steel with addition of Si and Mo under quasi-high temperatures

In order to study rolling contact fatigue characteristics of newly developed bearing steel SBS1, principally in a quasi-high temperature, the washer and ball specimens made of SBS1 were tested at a temperature of 403 K and also at noncontrolled temperatures under a rolling contact condition using a thrust bearing rolling fatigue testing machine. This test was also performed using conventional bearing steel SUJ2 for comparison. To discuss results about the rolling contact fatigue lives of the washers, microstructural changes of the fatigue-tested washers and balls were observed around the depth where the orthogonal shear stress and the maximum shear stress became maximum. The soaking test was also conducted at a temperature of 453 K using the balls, and we examined the changes of the hardness and the full width at half maximum by increasing the soaking time. It could be summarized from these investigations that the rolling contact fatigue life of the newly developed bearing steel SBS1 was much longer than that of the conventional bearing steel SUJ2, especially under a quasi-high temperature.