Effect of pre-deformation on corrosion fatigue crack growth of Type 316NG steel in 325 °C deaerated water

The pre-deformed 316NG (00Cr17Ni12Mo2N) was prepared by cold rolling at room temperature and hot rolling at 400°C. The effect of pre-deformation on fatigue crack growth both in 325 °C deaerated water and room temperature air was investigated. The effect of pre-deformation on corrosion fatigue crack growth (CFCG) in 325 °C deaerated water was much smaller than that on fatigue crack growth (FCG). The cold rolling significantly enhanced CFCG rates while the applied Δ K closed to 11 MPa•m^1/2 or the applied loading frequency decreased to 0.1Hz. The accelerating effect of hot rolling on CFCG tended to get evident until the pre-deformation increased to 30%. Dynamic recovery was observed near the corrosion fatigue crack tip in hot rolled 316NG, which may result in relatively low CFCG rates.