抄録
To investigate the effect of surface conditions on fatigue strength in gigacycle range of high carbon-chromium bearing steel, JIS SUJ2,cantilever-type rotating-bending fatigue tests were conducted using specimens with mechanical-polishing, electro-polishing and two kinds of shot-peening. Duplex S-N curve having surface fracture mode and internal one was obtained for the mechanical-and electro-polished specimen. Fatigue limit of surface fracture mode for the electro-polished specimens decreased as compared with the mechanical-polished one. On the other hand, single S-N curve due to the internal fracture mode appeared for the shot-peeing specimens and was not affected by the any surface conditions.
