Evaluation of Corrosion Resistance of Anti-Corrosive Paint by Investigation of Diffusion Limiting Current Density

J. Ocean Eng. Technol. 2009;23(4):64-68.

Moon Kyung-Man,Kim Yun-Hae,Lee Myung-Hoon,Lee In-Won,Park Hyun,Chun Ho-Hwan

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 Naval Architecture and Ocean Engineering Pusan Nation Univ,Dept. of Nav

확산한계전류밀도 고찰에 의한 방청도료의 내식성평가

문경만,김윤해,이명훈,이인원,박현,전호환

한국해양대학교 조선기자재공학부,한국해양대학교 조선기자재공학부,한국해양대학교 기관시스템공학부,부산대학교 조선해양공학과,부산대학교 조선해양공학과,부산대학교 조선해양공학과

Keywords: Corrosion resistance, Anti-corrosive paint, Electrochemical methods, Resin series, Diffusion limiting current density

핵심용어: 내식성, 방청도료, 전기화학적방법, 수지계열, 학산한계전류밀도

Abstract

It has been observed that coated steel structures deteriorate more rapidly than the designed lifetime due to acid rain caused by air pollution, etc. Therefore, improving the corrosion resistance of anti-corrosive paint is very important in terms of safety and the economic point of view. In this study, the corrosion resistance of five kinds of anti-corrosive paints, including the Acryl, Fluorine, and Epoxy resin series, were investigated with electrochemical methods, such as corrosion potential measurements, polarization curves, diffusion limiting current density, etc. As a result, the corrosion resistance of the F101 specimen with the fluorine resin series was found to be superior to the other specimens, while E100 with the epoxy resin series also showed a somewhat good corrosion resistance. Furthermore, it was observed that the amount of water and oxygen entering the inner side of a painted film increased with an increase in immersion time, irrespective of the kind of resin series. However, the oxygen diffusion limiting current density of a specimen with good corrosion resistance was relatively decreased compared to other specimens, because of the difficulty of oxygen diffusion penetrating to the inner side of the film. Consequently it is suggested that we can qualitatively evaluate the corrosion resistance of an anti-corrosive paint by measuring the diffusion limiting current density as an electrochemical method.