The electrochemical impedance spectroscopy(EIS) was used to study the electrochemical corrosion behavior of twelve coating systems including four primer, epoxy intermediate coat and polyurethane topcoat. The evolution of impedance spectra of the four primers immersed in sodium chloride solution was investigated. The protective properties of the primer, the impedance of the two-layer system and the impedance spectra of three-layer composite system after different periods of immersion were compared based on the study. The results indicate that the protective properties of three-layer composite system was better than that of two-compound system, while that of the single coating system was the worst. The protective properties of three-layer composite system with anticorrosive epoxy coating is the best among all the systems. Paint finish and intermediate coating play the role of isolation from the outside medium and protection of the primer in the coating system based on the characteristic of the electrochemical impedance spec-troscopy. The electrochemical impedance spectroscopy can be used to research the corrosion resistance of coating systems.%采用电化学阻抗谱(EIS)研究了由4种常用底漆、环氧云铁中间漆和聚氨酯面漆复合而成的12种涂层体系的电化学腐蚀行为,考察了4种底漆的EIS在NaCl溶液浸泡过程中的演化,并以此比较底漆的防护性能,考察了2层复合涂层体系的阻抗大小以及3层复合涂层体系在浸泡不同周期后的EIS.结果表明:3层复合涂层体系的防护性能最好,2层复合涂层体系次之,单涂层体系最差,其中以环氧防锈漆3层复合涂层体系的防护性能最优；面漆和中间漆在涂层体系中起到了隔绝外界介质和保护底漆的作用；EIS可用于研究涂装体系的防腐性能.
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