Influence of Direct Current Electric Field on the Formation,Composition and Microstructure of Corrosion Products Formed on the Steel in Simulated Marine Atmospheric Environment  

作　　者：Nian-Wei Dai Jun-Xi Zhang Qi-Meng Chen Xin Zhang Fa-He Cao Jian-Qing Zhang 

机构地区：[1]Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, Shanghai University of Electric Power [2]Department of Chemistry, Zhejiang University

出　　处：《Acta Metallurgica Sinica(English Letters)》2016年第4期373-381,共9页金属学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.51271110);supported by Science and Technology Commission of Shanghai Municipality(No.14DZ2261000)

摘　　要：X-ray diffraction, Raman spectroscopy and scanning electron microscopy were employed to investigate the effects of the DC electric field on the composition, formation and structure of corrosion products formed on the surface of the steel immersed in NaCl solution. The results show that goethite （α-FeOOH）, akaganeite （β-FeOOH）, lepidocrocite （γ- FeOOH） and magnetite （Fe3O4） are the major constituents among the corrosion products. The arrangement of different levels of the DC electric field intensity gives rise to the following results. The little higher DC electric field intensity （around 100-200 kV/m） promotes the crystallinity and growth of y-FeOOH; obviously, much higher DC electric field intensity （greater than 400 kV/m） prevents the growth of α-FeOOH and facilitates the generation of Fe3O4. Both the promotional growth of γ-FeOOH and suppression of α-FeOOH growth indicated the weakness of the protectiveness of the rust layer. Consequently, the suppression of the transformation of α-FeOOH from y-FeOOH favors the yield of the Fe3O4, which works as a large cathode area and would be about to quicken the subsequent steel corrosion.X-ray diffraction, Raman spectroscopy and scanning electron microscopy were employed to investigate the effects of the DC electric field on the composition, formation and structure of corrosion products formed on the surface of the steel immersed in NaCl solution. The results show that goethite （α-FeOOH）, akaganeite （β-FeOOH）, lepidocrocite （γ- FeOOH） and magnetite （Fe3O4） are the major constituents among the corrosion products. The arrangement of different levels of the DC electric field intensity gives rise to the following results. The little higher DC electric field intensity （around 100-200 kV/m） promotes the crystallinity and growth of y-FeOOH; obviously, much higher DC electric field intensity （greater than 400 kV/m） prevents the growth of α-FeOOH and facilitates the generation of Fe3O4. Both the promotional growth of γ-FeOOH and suppression of α-FeOOH growth indicated the weakness of the protectiveness of the rust layer. Consequently, the suppression of the transformation of α-FeOOH from y-FeOOH favors the yield of the Fe3O4, which works as a large cathode area and would be about to quicken the subsequent steel corrosion.

关 键 词：STEEL Atmospheric corrosion RUST Electric field Raman spectroscopy 

分 类 号：TG172[金属学及工艺—金属表面处理] TG142[金属学及工艺—金属学]