Fretting damage of sus 304 in a vacuum

Fretting damage morphology was investigated for SUS 304 stainless steel in a vacuum (4X10^-3 Pa) by varying the number off retting cycles, the normal load and slip amplitude, in which the generation of surface cracks was examined by SEM observation. The condition for the generation of cracks and the morphology of the cracks depended on both load and slip amplitude. Cracks initiated at the boundary between fretted and unfretted areas after a certain number of cycles Long cracks Were formed Under higher loads at a constant slip amplitude. The length of a crack increased with an increase in slip amplitude, followed by a stop of he crack generation at a certain slip amplitude at a constant load. The slip amplitude for the limitation of the crack generation was approximately proportional to the load.