Abstract
In order to evaluate the influence of artificial defects (holes) on rolling contact fatigue strength of steel rollers, the steel rollers with artificial defects were contact fatigue-tested under a sliding-rolling contact condition. The crack propagation behavior was investigated. The rolling contact fatigue strength of rollers with artificial defects was smaller than those of rollers with non-artificial defect. In the case of rollers with artificial defects, cracks occurred in the vicinity of holes. The initial crack propagated from the hole was parallel to the roller surface. Then the crack propagated in a range of 20 degrees -45 degrees for the crack that progressed in parallel with the surface. To examine what kind of subsurface stress affected the crack, internal stresses around hole were calculated with FEM. The factor that affected the initiation of cracks would be the maximum shear stress τ_<max>, and the factor that affected the propagation of cracks would be the orthogonal shear stress τ_<yz>.
