Evaluation of Degradation of High Performance Organic Coatings under Outdoor Salt Spray Test

A high performance organic coating is used for the corrosion protection of large steel constructions. Since the degradation of the coating takes long time, the degradation evaluation is difficult. Previously, the degradation of a coating was evaluated by electrochemical impedance method. However, these subjects of research were a coating with thin film thickness. Therefore, the evaluation of the high performance or the thick thickness coating is insufficient. The authors reported on the evaluating of the growth of the blistering of the coating. In this research, the degradation of the coating before blisters occur was evaluated as the penetration by water and chloride ion. The acceleration of coating degradation could be used as an outdoor salt spray test.