Methods for evaluation of coating performance based on AC impedance technique

  Objectives  Coating on the surface of ships is a common method of ship anti-corrosion. The corrosion resistance of the coating directly reflects the corrosion degree of the ship's surface. Although coating has been used as an effective anti-corrosion technology on ships for decades, there has been a lack of rapid and effective test methods for the corrosion resistance of the coating.

  Methods  In this paper, a reasonable equivalent circuit model of the coating system was established, and the salt-fog aging and UV aging coating performance experiments were carried out on the test coating by AC impedance testing technology. The Matlab data processing software was used to calculate and analyze the experimental results.

  Results  The parameters of each equivalent component in the coating system were obtained to evaluate the performance of the coating, and the electrochemical evaluation criteria for coating aging failure were established.

  Conclusions  The results of salt-fog aging and UV aging coating performance experiments show that the performance of the coating can be comprehensively evaluated quickly and accurately based on the AC impedance technique and the corresponding electrochemical evaluation parameters.