ABSTRACT
In fact, the potential of the bare steel with atmospheric rust or mill scale will be very much more positive when it is immersed in the seawater. This means that sacrificial anode cathodic protection systems, designed according to Det Norske Veritas to give the initial current densities will actually deliver very much higher currents than the code values during the early stages of polarisation. Although that claim might overstate their importance somewhat, it is certainly true that the quality of the calcareous deposit formed during the initial polarisation has a profound effect on the subsequent current density needed for protection throughout the remainder of the life. The electrochemistry involves conducting the polarisation experiments to create the deposits and to measure their effects on the electrode behaviour. The surface analysis employs sophisticated techniques for characterising the composition and structure of the deposits.
