Studies on electrochemical noise analysis of an epoxy coating/metal system under marine alternating hydrostatic pressure by pattern recognition method

The electrochemical noise (EN) measurement of an epoxy coating/metal system under alternating hydrostatic pressure (AHP) was performed, and pattern recognition (PR) method was utilized for EN data analysis to evaluate the protective performance of the coating system. The results indicated that EN time records displayed different characteristics for corrosion states of the coated steel under AHP, some certain potential spikes should be due to a residual effect of the pressure change instead of a corrosion effect. The PR procedures, including principal component analysis (PCA), hierarchical agglomerative cluster analysis (HACA) and discriminant analysis (DA), were applied to the establishment of an evaluation model for EN statistical parameters. Based on the established discriminant functions, different failure stages of the other coatings under AHP can be identified conveniently and accurately.