Propagation behavior of an internal crack of a radical nitrided bearing steel

摘要: In order to investigate the propagation behavior of an internal crack in surface treated steel, rotaing bending fatigue tests were carried out for a radical-nitrided bearing steel. The fracture occurred from specimen under high stress levels, whereas fish-eye low levels. Consequently, S-N curve was duplex one. A circular trace observed inside when two-step variable amplitude test. It suggested that formed by change amplitude. Moreover, size depending on level and number cycles, it concluded there is limit meaning most life occupied growth small crack.