Cathodic disbonding of a thick polyurethane coating from steel in sodium chloride solution

摘要: The cathodic disbonding of a thick, pigmented polyurethane coating from steel in 3.5 wt.% NaCl solution was studied by using an electrochemical AC impedance technique. Double-cylinder electrolyte cells were designed to separate the measurements process influence artificial defect. It found that for coating, more important transport pathway reactive species is along coating/steel interface rather than through coating. There existed delay time process, and polarization not predominant factor determining behavior early stages. thick which applied on well sand-blasted surface, had excellent resistance disbonding.