Long‐term corrosion fatigue behaviour of structural materials

In this paper, long‐term corrosion fatigue behaviour of structural materials such as 12Cr stainless steel and Ti−6Al−4V alloy for steam turbine moving blade and high‐strength steels for ship and offshore structures up to the ultrasonic frequencies is reviewed mainly on the basis of the author's experimental results. The emphasis is focused upon the corrosion fatigue behaviour of 12Cr stainless steel in NaCl and NaOH aqueous solutions. It is shown that the corrosion fatigue strength of 12Cr stainless steel is strongly dependent on NaCl content in aqueous solution. It is also exemplified that the ultrasonic corrosion fatigue strength of 12Cr stainless steel decreases remarkably if an aggressive environment like 40% NaOH aqueous solution should be formed at the crack bottom even in a dilute NaOH aqueous solution.