Abstract
A novel electrochemical method was developed to investigate underfilm corrosion of a temporarily protective oil coating. A multiple wire electrode was used to allow electrochemical parameters and their distributions to be measured directly from the coating/metal interface. This made it possible to measure electrochemical parameters that were related to underfilm corrosion directly so as to study the mechanism of underfilm corrosion. Corrosion currents of microcorrosion cells were measured. Anodic and cathodic areas of an underfilm corrosion cell also were documented. Results showed that underfilm corrosion taking place at the coating/metal interface was heterogeneous. It was suggested that this method is helpful in investigating the mechanism of underfilm corrosion and in studying the degradation process of oil coatings.