Simulating Study of Atmospheric Corrosion of Galvanized Steels: Influence of Zinc Rusts on the Formation of 尾-FeOOH Rust Particles by Aerial Oxidation of Aqueous FeCl2 Solution

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• 作者：Hidekazu Tanaka ; Tatsuya Kitazawa ; Nagisa Hatanaka ; Tatsuo Ishikawa ; Takenori Nakayama
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2012
• 出版时间：January 11, 2012
• 年：2012
• 卷：51
• 期：1
• 页码：248-254
• 全文大小：977K
• 年卷期：v.51,no.1(January 11, 2012)
• ISSN：1520-5045

文摘

To simulate the corrosion of galvanized steel in a marine zone, steel rust of 尾-FeOOH particles was prepared by aerial oxidation of aqueous FeCl₂ solutions containing ZnCl₂ and zinc rusts such as ZnO and zinc hydroxychloride (Zn₅(OH)₈Cl₂路H₂O, ZHC). The crystallinity and particle size of 尾-FeOOH were slightly decreased by adding the ZnCl₂. The produced particles contained a small amount of ZnCl₂, while the zinc rusts of ZnO and ZHC markedly impeded the crystallization and particle growth of 尾-FeOOH. In the presence of a large amount of zinc rusts, the formation of 尾-FeOOH was suppressed and 纬-FeOOH and ZHC of which the particle size was larger than that of 尾-FeOOH were generated. The inhibitory effect on the formation of 尾-FeOOH was on order of ZHC 鈮?ZnO ZnCl₂. The effect of zinc rusts was ascribed to the increment of solution pH by dissolution of rust particles and adsorption of Zn(II) on a precursor of 尾-FeOOH particles. The adsorption of CO₂ on the products was also suppressed by the addition of ZnCl₂ and zinc rusts. These results imply that the 尾-FeOOH rust formed on galvanized steel in a marine environment is more compact, leading to improved corrosion resistance. However, existence of a large amount of zinc rust particles inhibits the formation of a compact rust layer and lowers the ability for corrosion resistance.