Study of anti-contamination performance of temporarily protective oil coatings using wire beam electrode

A novel electrochemical method was developed to investigate the anti-contamination performance of temporarily protective oil coatings. Results showed that salt contamination on the metal substrate had influence on the heterogeneous distributions of corrosion potential, polarization resistance and their regularities. With increasing of salt contamination degree, the corrosion potentials distribution of oil coatings followed a discontinuous binomial probability distribution, whereas the anodic polarization resistance (Ra) distribution of oil coatings transformed from a log-normal probability distribution to an exponential probability distribution and then to a discontinuous binomial probability distribution, the cathodic polarization resistance (Rc) distribution of oil coatings followed a log-normal probability distribution. The influence of salt contamination on Ra and Rc of oil coatings was different. It was suggested that it is helpful to study the process of underfilm corrosion, and evaluate the performance of contamination resistance of oil coatings by using wire beam electrode.