Relationship between the specific surface area of rust and the electrochemical behavior of rusted steel in a wet–dry acid corrosion environment
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- 作者：Wei Liu ; Qing-he Zhao ; Shuan-zhu Li
- 关键词：steel corrosion ; rust ; specific surface area ; electrochemical behavior ; polarization curves
- 刊名：International Journal of Minerals, Metallurgy, and Materials
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：24
- 期：1
- 页码：55-63
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Materials Science, general; Metallic Materials; Characterization and Evaluation of Materials; Ceramics, Glass, Composites, Natural Materials; Surfaces and Interfaces, Thin Films; Tribology, Corrosion
- 出版者：University of Science and Technology Beijing
- ISSN：1869-103X
- 卷排序：24
文摘
The relationship between the specific surface area (SSA) of rust and the electrochemical behavior of rusted steel under wet–dry acid corrosion conditions was investigated. The results showed that the corrosion current density first increased and then decreased with increasing SSA of the rust during the corrosion process. The structure of the rust changed from single-layer to double-layer, and the γ-FeOOH content decreased in the inner layer of the rust with increasing corrosion time; by contrast, the γ-FeOOH content in the outer layer was constant. When the SSA of the rust was lower than the critical SSA corresponding to the relative humidity during the drying period, condensed water in the micropores of the rust could evaporate, which prompted the diffusion of O2 into the rust and the following formation process of γ-FeOOH, leading to an increase of corrosion current density with increasing corrosion time. However, when the SSA of the rust reached or exceeded the critical SSA, condensate water in the micro-pores of the inner layer of the rust could not evaporate which inhibited the diffusion of O2 and decreased the γ-FeOOH content in the inner rust, leading to a decrease of corrosion current density with increasing corrosion time.