Investigation on rolling contact fatigue of 55 medium-carbon steel

Rolling contact fatigue characteristics of 55 medium-carbon steel provided by two different steel mills have been investigated. The results indicate that the rated contact fatigue life (L10) of steel A is higher than that of steel B. All samples show typical contact fatigue characteristics with spalling, delamination, pitting and debris. Moreover, all samples show specific fatigue propagation characteristics which is consistent with the rolling direction of the steel ball. The frequency of the inclusions B, D and Ds in steel B is significantly higher than that in steel A, which have great influence on the contact fatigue life.