Flaking failure in rolling contact fatigue caused by indentations on mating surface (I): Reproduction of flaking failure accompanied by cracks extending bi-directionally relative to the load-movement

摘要: The crack growth in rolling contact fatigue has been investigated with a newly devised testing rig. A surface normally extends the direction of load-movement, and flaking failures accompanied by cracks extending opposite to load-movement are rarely observed. However, some situations, appear an as not yet clarified mechanism. In this study, double-roller type rig reproduce opposite-direction growth. Equally spaced artificial indentations marked on one roller, while other roller is defect-free. that set-up, bi-directionally almost always occurs defect-free surface. appearance consistent throughout tests, but cycles failure vary according test conditions such (1) load, (2) additional tangential force between rollers, (3) number indentations, (4) whether operated driver or follower, (5) rotational speed, (6) size indentations.