抄録
The Rotating bending fatigue tests were done using notched PDI with ion carburizing. The plain specimen with ion carburized about 30MPa than the virgin PDI, and the fatigue strength of the carburized ion notched specimens were given an equivalent to the virgin PDI. Especially, the ion carburized notched specimens are effective materials they have a better effect than lower that the notched PDI. In the recapitulation, on the element parts demanded a shallow notch, the clear distinction appeared whether ion charge or not, respectively. An important point is that carburized PDI presented two bending S-N curve not clear in high cycle fatigue. If the hardness is constantly holed to an internal point, the shape of S-N curve is unclearly appeared. But, its phenomena appeared from ion boundary layer by observation of the SEM photograph. The ion carburizing can control the charged depth by the sputtering time. Consequently, this method warrants consideration as a non-polluting process and economical use of energy. (1) Pcn S-N curve by ion carburizing effect was controlled to affect on the crack propagating in our researched meso-scopic structure. (2) Typical fracture of quasi-fish eye in the surface vicinity can be decided on a/b. Where, a : equivalent defect radius, b : equivalent cleavage radius. Accordingly, it is expressed by life cycle of S-N curve.
