抄録
In order to assess the sliding-rolling contact fatigue lives of surface-hardened sintered rollers from the view point of linear fracture mechanics, the crack propagation behavior has been investigated under a sliding-rolling contact condition. The surface-hardened rollers which have three kinds of artificial defects were fatigue tested, and the crack propagation rate was measured. The crack propagated from the hole was almost parallel to the roller surface. Therefore, the crack propagation under a sliding-rolling contact condition was supposed to be in the mode II. The parameters m and C in Paris's law were obtained from this experiment. Using these parameters, the fatigue lives of the surface hardened sintered roller were estimated. The estimated fatigue lives were almost the same as the experimental ones. The fatigue lives of the sintered rollers depend mainly on the pore distribution and the hardness. The relationship between the parameters in Paris's law and the hardness obtained in this paper might help to assess the sliding-rolling contact fatigue life.
