抄録
In order to examine the fine granular area (FGA) formed timing in high cycle fatigue for bearing steel, the rotating bending tests were carried out under two conditions of decremental step loading. The cumulative damage value of stress cycles at the high stress level was 0.1 against the average of the fatigue life in the interior inclusion induced fracture. And the cumulative damage values were 0.14 and 0.32 against the average of the fatigue life in the surface induced fracture. In this experiment, the roll processing performed in order to improve a fatigue life in surface induced fracture mode. From the experimental results, the different fine granular area aspect from stress constant cases was observed.
