Effect of Predeformation on Corrosion Fatigue Crack Growth of Type 316NG Steel in 325°C Deaerated Water

The predeformed 316NG (00Cr17Ni12Mo2N) was prepared by cold rolling at room temperature and hot rolling at 400°C. The effect of predeformation on fatigue crack growth both in 325°C deaerated water and room temperature air was investigated. The effect of predeformation on corrosion fatigue crack growth (CFCG) in 325°C deaerated water was much smaller than that on fatigue crack growth. The cold rolling significantly enhanced CFCG rates while the applied ΔK closed to 11 MPa√m or the applied loading frequency decreased to 0.1 Hz. The accelerating effect of hot rolling on CFCG tended to become evident until the predeformation 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.