Fracture mechanism of shot-peened maraging steel in long-life region

摘要

The influence of reversion austenite on the fatigue strength of shot-peened maraging steel was investigated under rotating bending fatigue in order to achieve further improvement of fatigue strength in long life region. Fracture origin changed from the surface to the internal of a specimen with decrease in stress level. Fatigue strength at low stress levels, where internal fracture occurred, increased by formation of reversion austenite. This is mainly caused by the suppression effects of reversion austenite on the growth of a small crack and the intergranular crack. By formation of reversion austenite, a clear fish-eye was observed.