Fatigue mechanism of a coating film under rolling contact loading: Study of methods for evaluation of rolling contact fatigue strength of coating films (2nd Report)

摘要

In the previous report, to establish an evaluation method for rolling contact fatigue strength of a coating film, the endurance limit of a coated roll under contact loading was investigated and crack initiation was found to dominate the determination of the endurance strength. The authors proposed that the mechanism of cracking was a fatigue process caused by a compressive tangential stress under contact loading. So, in this study, static and fatigue properties of Cr-plating films under bending, tension and compression were obtained. And these properties were compared with rolling contact fatigue strengths of Cr-plating film on a fatigue endurance diagram. As a result, we found that the rolling contact fatigue strength agrees well with the value estimated from the static and fatigue properties, and the rolling contact fatigue strength of Cr-plating film could be estimated from the static and fatigue properties. Also, it was found that residual stress in the Cr-plating had a large effect on the rolling contact fatigue strength.