Rate-determining processes for corrosion fatigue crack growth in ferritic steels in seawater

The results of recent experiments on measuring corrosion fatigue crack propagation rates in structural steel immersed in seawater with and without cathodic polarisation are reported. These include measurements of electrochemical potentials near the growing crack tip. The experiments have been designed to learn more about the mechanisms and rate-determining processes influencing the rate of crack growth. From these and other results in the literature, deductions are made about the relative importance of mechanical and electrochemical limitations on the rate of crack propagation.