Evaluation of the Long-Term Performance of Marine and Offshore Coatings System Exposed on a Traditional Stationary Site and an Operating Ship and Its Correlation to Accelerated Test

Abstract

Anticorrosive coatings are widely used to protect steel against corrosion. Different standards exist to access the corrosion performance of anticorrosive paints. Among them, the so-called neutral salt spray test (NSST-ISO 9227) or cycling corrosion tests ISO 12944-6, ISO 12944-9, NACE TM0304, or NACE TM0404 can be named. It is well-known that some accelerated corrosion tests are not fully representative of the field exposure results. However, a lack in the literature exists correlating accelerated tests to field exposure, especially when long-term durations are considered. In this study, 11 different organic coatings have been investigated in terms of coating resistance to corrosion creep in two types of field exposure sites, namely a stationary site and an operating ship, and their performance was compared to two accelerated tests (ISO 12944-9 and modified ASTM D5894 standard). The results showed differences in the sites’ corrosivity and the coating systems’ performance as a function of the exposure sites. A lack of correlation exists between the ISO 12944-9 standard and the stationary site, due to the latter’s high corrosivity, while, to the contrary, a satisfying correlation with the operating ship was demonstrated; whereas, the modified ASTM D5894 standard showed a satisfying correlation with both types of sites.