Research Of Coating Protective System Accelerated Corrosion Tests

Metal surface coated with organic coating is the most widely used, most economical and effective anti-corrosive approach. The metal material will be seriously corroded due to the failure of coating, resulting in significant economic losses and fatalities. Therefore, there will be important theoretical and practical significance for selecting organic coating’s application and being provided theories to build and develop new protective coating systems through research of coating corrosion failure mechanisms and establishment transfer model of corrosive medium in the organic coating by accelerated tests.The coating accelerated corrosion tests includes loop tests consist of UV exposure and cycle infiltration and immersion tests. The variations of different substrates, surface treatments and different coatings protective systems’corrosion law and electrochemical behaviors was studied by accelerated tests, and the coating’s corrosion law and electrochemical behaviors under different medium was also discussed. Meanwhile, optical microscope was used to observe the changes of coating’s surface morphology and the components of coating before and after experiment were analyzed by infrared spectroscopy.The results of experiment showed that the surface gloss and thickness of samples were changed with experimental cycles under UV exposure and cycle infiltration tests due to UV degradation, hydrolysis of water penetration and cyclic dry/wet. The samples surface produced micropores which would expand and increase with experimental cycles’ addition. The corrosion law was less diverse between coating protective systems of different substrates or the type of surface treatment methods,the type of coating would influence the hydroscopicity of coating protective systems, the H2 type of coating is better.The EIS of the protective coating system was declining with the increase of experimental cycles, different surface treatments and different coating had a great impact on the performance of protective coating system, the H2 type of coating is better. Under the interaction of the UV and the corrosion media, the organic coatings have the photochemical reaction.With the infiltration of the corrosion media, the protection performance of the organic coating is declining.