Evaluation of Corrosion Characteristics of Underwater Hardening Paint

doi:2011.25.2.85

J. Ocean Eng. Technol. > Volume 25(2); 2011 > Article

J. Ocean Eng. Technol. 2011;25(2):85-91.
DOI: https://doi.org/10.5574/KSOE.2011.25.2.085

Moon Kyung-Man,Oh Min-Seok,Lee Myung-Hoon,Lee Syung-Yul,Kim Yun-Hae

Dept. of Marine Equipment Engineering Korea Maritime Univ.,Dept. of Marine Equipment Engineering Korea Maritime Univ.,Dept. of Marine System Engineering Korea Maritime Univ.,Dept. of Marine Equipment Engineering Korea Maritime Univ.,Dept. of Marine Eq

수중 경화형도료의 부식특성에 관한 전기화학적 고찰

문경만,오민석,이명훈,이성렬,김윤해

한국해양대학교 조선기자재공학부,한국해양대학교 조선기자재공학부,한국해양대학교 기관시스탬공학부,한국해양대학교 조선기자재공학부,한국해양대학교 조선기자재공학부

Keywords: Corrosion resistance, Underwater hardening paints, Electrochemical methods, Resin series, Diffusion limiting current density

핵심용어: 내식성, 수중경화형도료, 전기화학적방법, 수지계열, 확산한계전류밀도

Abstract

Many protection methods such as surface coating, electric protection, or other methods have been applied to the numerous steel structures widely used in continental and marine areas to control their corrosion, which is done from an economic point of view. Most of these steel structures are primarily protected by coating methods. However, some steel piles under seawater are protected by the electric protection method, that is, either using an impressed current or a sacrificial anode method. Furthermore, environmental contamination may cause a severely corrosive environment, which, in turn, causes the accelerated corrosion of steel structures. Subsequently, coated steel structures could deteriorate more rapidly than the designed lifetime because of the acid rain caused by air pollution, etc. Therefore, a coating of marine paint exposed to seawater, that is, underwater hardening painting, is increasingly required to be fast drying as well as highly corrosion resistant. In this study, five types of underwater hardening paints were prepared with different resin series and additives. Their corrosion and water resistances were investigated using electrochemical methods such as corrosion potential, polarization curves, impedance and cyclic voltammogram measurements, etc. Even though it is generally accepted that the corrosion resistance of bare steel tends to increase with a shift of the corrosion potential in the noble direction, the corrosion resistance of a sample with a coating exhibited a relatively better tendency when it had a lower corrosion potential in this study. The corrosion current density was also decreased with a decrease in the diffusion limiting current density, which may mean that there is some relationship between corrosion and water resistance. The S sample of the ceramic resin series showed the relatively best corrosion and water resistance among those of samples, while the worst corrosion and water resistance were observed for the R sample of the epoxy resin series. The corrosion and water resistance of those samples tended to deteriorate with an increase in the immersion days, and their corrosion and water resistances were considered to be apparently improved by the types of resin and additives.