AN EIS STUDY OF THE ANTICORROSION PERFORMANCE OF EPOXY RESIN COATING

The performance and failure process of organic coating/metal system was studied.The samples with coating immerged in 3.5% NaCl solution were tested by means of electrochemical impedance spectoscopy(EIS),combined with laser lanman spectroscopy(EIS) and scanning electron microscopy (SEM).The emphasis was put on the corrosive medium transportion and the transformation at the interface between coating and metal.The impedance decreased at the beginning of immersion,then increascd in the metaphase of immersion,and again became minished at last,which was related to the formation of corrosion product films.The concentration of Cl- in the coating increased with the immersion going on,resulting in damage of corrosion product.