Application of Scanning Kelvin Probe Surface Potential Characteristic Parameters to lnvestigation of Ognic Coating Reteriortion

The deterioration process of organic coatings exposuring in 3.5% NaCl solution was investigated using the electrochemical impedance spectroscopy (EIS) and scanning Kelvin prove (SKP) to study the effectiveness of SKP in studying corrosion occurring under organic coatings. SKP surface potential characteristic parameters Vmin and (Vmax－Vmin) were analyzed . For the first time, the gradmax, which is the maximum surface potential gradient, was proposed. Surface potential characteristic parameters showed good relationship with the results of EIS. Using the surface potential characteristic parameters is a good method to evaluate the deterioration of organic coatings, the maximum surface potential gradient gradmax, is a useful method to calculate the corrosion trend and speed under organic coatings.