Abstract
Organic coatings are widely used to control of the corrosion of a steel structure. The water in coatings may cause the coatings to swell, leading to the degradation of the coatings. In addition, water affects the permeation of oxygen and other corrosive agents, and consequently, the presence of such substances at coating-metal interface promotes corrosion of the metal substrate. In this study, the anticorrosive properties of 4 types of coating, such as epoxy-epoxy, epoxy-urethane, urethane-epoxy, urethane-urethane, were evaluated. The evaluation tests were conducted under cyclic water-absorption/desorption conditions, consisting of alternative exposure to diluted 0.001M-LiCl(a$H_2O$≒1) and concentrated 10M-LiCl(a$H_2O$≒0.15). The anticorrosive performance of coatings was found to decrease in the order of urethane-urethane > urethane-epoxy > epoxy-epoxy coating.