Corrosion fatigue behavior and crack-tip characteristic of 316LN stainless steel in high-temperature pressurized water

摘要

The corrosion fatigue (CF) behavior and crack tip characteristic of 316LN stainless steel in 325 degrees C water at different strain rates were investigated under a strain amplitude of 0.6%. With decreasing the strain rate from 0.4% s(-1) to 0.0004% s(-1), the CF life decreased linearly in log-log plot. More obvious reduction of CF life at low strain rate was due to the environmental damage. The morphology of cracks and the dislocation density near the crack-tip front exhibit a significant different under different strain rate conditions. The hydrogen enhanced localized plasticity mechanism is discussed to explain the micro-damage process at different strain rates in high-temperature water. (C) 2019 Elsevier B.V. All rights reserved.