Influences of Stress Ratios on Cyclic Stress Corrosion Crack Growth Characteristics of a High-strength Steel

抄録

Influences of stress ratios and stress cycle frequencies on cyclic stress corrosion crack growth characteristics of a high-strength steel have been investigated. The influences of stress ratios on crack growth rate under cyclic SCC are clearly distinguished between above and below K_ISCC. In the range of K_max, K_FSCC≤ K_max < K_ISCC, a decrease of R causes not only an increase of da/dt but also a lowering of K_FSCC. In this region crack growth rate is cycle-dependent, and the crack growth by a cyclic SCC is dominant. In high K_max, K_max≥ K_ISCC, time-dependent da/dt increases with an increase of R and the crack growth by a static SCC is dominant.