An evaluation of coil coating formulations in marine environments

Abstract

This paper describes the activities carried out between 1996 and 1999 by the Group 6 "Coil Coating" in the frame of the Patina Network (Anticorrosive Protection in the Atmosphere), sponsored by CYTED. It includes the work accomplished by Science and Technology Institutions of the Ibero-American region on different painting systems supplied by Production Sectors of companies of participating countries. Twelve coil coating systems of varied protective characteristics were exposed outdoors, at three different marine atmospheric conditions of the MICAT Ibero-American Test Stations Network (CYTED). Steel, galvanised steel and Galvalume® samples coated with any of the painting systems built up with and without incision were used. In each case, the paint coating deterioration was evaluated according to ISO 4628-1 to ISO 4628-6, ISO 4623 and ASTM D-3274 standards. Results found after 12, 24, 36 and 42 months are discussed, in function of the aggressive agent characteristics of the test environment. These results are compared with those found in a salt spray chamber test, showing similar behaviour. Electrochemical impedance spectroscopy (EIS) was also applied on replicated samples of each material after different exposure periods, to evaluate deterioration of the metallic substrate/organic coating systems in the ambient conditions tested.