| Atmospheric corrosion monitoring of low carbon steel by using EIS comb sensor in the typical exposure site of China Junhua Dong1; Xin Mu1; 1SHENYANG NATIONAL LAB FOR MATERIALS SCIENCE, Shenyang, China; PAPER: 221/Corrosion/Regular (Oral) SCHEDULED: 14:50/Tue. 29 Nov. 2022/Andaman 2 ABSTRACT: As we all know, atmospheric corrosion is electrochemical corrosion of metal under thin liquid film in wet-dry cycle environment. Because it is difficult to carry out electrochemical measurement under the condition of thin liquid film, monitoring the electrochemical behavior and corrosion rate of atmospheric corrosion has always been a hot spot in the field of corrosion research, and it is a challenging task to carry out in-situ electrochemical monitoring outdoors. In this work, the comb-shaped low carbon steel electrochemical impedance spectroscopy probe was used to monitor the typical atmospheric environment in China for one year. The results show that the real wetting time of metal surface can be calculated by using high-frequency impedance data, while the corrosion rate of metal can be calculated by using low-frequency impedance data, and there is a monotonic linear response relationship between high-frequency impedance and low-frequency polarization impedance. The wetting grade of metal surface reflected by high-frequency solution resistance and the environmental corrosion grade reflected by low-frequency polarization resistance are basically consistent with the classification of corresponding environment made by ISO9223-9226. References: 1. Mansfeld, Florian, Monitoring of Atmospheric Corrosion Phenomena with Electrochemical Sensors, JOURNAL OF THE ELECTROCHEMICAL SOCIETY 135 (6) (1988) 1354–1358. 2. NISHIKATA, ICHIHARA, TSURU, An application of electrochemical impedance spectroscopy to atmospheric corrosion study, Corrosion Science 37 (6) (1995) 897–911. 3. A. Nishikata, Y. Ichihara, T. Tsuru, Electrochemical impedance spectroscopy of metals covered with a thin electrolyte layer, Electrochimica Acta 41 (7) (1996) 1057–1062. https://doi.org/10.1016/0013-4686(95)00438-6. 4. C. Thee, L. Hao, J. Dong, X. Mu, X. Wei, X. Li, W. Ke, Atmospheric corrosion monitoring of a weathering steel under an electrolyte film in cyclic wet–dry condition, Corrosion Science 78 (2014) 130–137. https://doi.org/10.1016/j.corsci.2013.09.008. 5. C. Thee, L. Hao, J. Dong, X. Mu, W. Ke. Numerical Approach for Atmospheric Corrosion Monitoring Based on EIS of a Weathering Steel. Acta Metallurgica Sinica, 2015, 28(2):261-271. |
