Abstract
Two-cylinder type rolling contact fatigue (RCF) testing under an insufficient lubricating condition was conducted to investigate the mechanism of peeling, in which many small cracks were observed at RCF surfaces. The effect of black oxide treatment on the suppression of peeling was also investigated. Surface roughness of two-cylinder sets made of JIS-SUJ2 were adjusted to bring about peeling on the driven cylinder surface, which had a lower surface roughness. Measurement of surface roughness and observation of surface texture were carried out by using a laser microscope and a field emission scanning electron microscope (FE-SEM), respectively. The results showed that the initial cracks of peeling were formed by plastic deformation, which occurred due to the severe contacts of surface roughness asperities. When the black oxide treatment was applied to the driving cylinder, a reduction of driving cylinder’s surface roughness during rolling contact, i. e., “running-in”, was significantly promoted. This significant promotion of running-in leads to a reduction of the severity for asperity contact, and therefore results in the suppression of peeling.
