Effects of Microorganism on Corrosion of Zn-Al-Cd Sacrificial Anode in Natural Seawater
SONG Xiu-xia1,2, ZHANG Jie2, YANG Dong-fang1, DUAN Ji-zhou2
1. College of Fisheries and Life Science,Shanghai Ocean University,Shanghai 201306,China;
2. Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,Shandong,China
Abstract:The effects of the sterile seawater and natural seawater on corrosion of Zn-Al-Cd sacrificial anode were investigated by using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and fluorescence microscopy. The results show that the corrosion potential of sample in the sterile seawater is lower than that in the natural seawater at the beginning of experiment, but at the late of experiment, the result is opposite. The EIS results show that the Rct value in the sterile seawater is much smaller than that of anode in natural seawater, which is because in the natural seawater, a layer of biofilm through the metabolic activities of bacteria is formed on the sample surface. The biofilm could prevent the sample from contacting with seawater directly and slow down the corrosion rate. SEM images reveal the presence of localized corrosion morphologies on the sample in the sterile seawater, while in natural seawater, the corrosion is much uniform. Fluorescence microscopy results show that the bacteria uniformly attach to the sample first, and then reunite uneven. About fourteen days later, the local biofilm forms, and it detaches from the sample finally because of the exhaustion of nutrients.
[1] 黄宗国,蔡如星.海洋污染生物及其防除[M].北京:海洋出版社,1984.127.[2] 付玉彬.生物膜对金属材料腐蚀性能影响的研究进展(上)[J].材料开发与应用,2006, 21(1): 34-39.[3] 武素茹,段继周,杜敏,等. 硫酸盐还原细菌和铁还原细菌混合生物膜对碳钢腐蚀的影响[J].材料开发与应用,2008, 23(3): 53-56.[4] 许昆明. 海洋生物膜的形成及其对金属腐蚀的影响[J].海洋科学,2008,32(9): 71-75.[5] 林晶.海水中微生物膜下金属材料初期腐蚀行为.哈尔滨:哈尔滨工程大学,2006.[6] DICKINSON W H, CACCAVO F, LEWANDOWSKI Z. The ennoblement of stainless steel by manganic oxide biofouling [J]. Corr Sci, 1996, 38(8):1407-1422.[7] 李异.锌合金牺牲阳极在海水的性能及应用[J].化工腐蚀与防护,1997,(2): 21-26.[8] 龙萍,李庆芬.热海水中Zn-Al-Cd阳极腐蚀机理的探讨[J].腐蚀科学与防护技术,2007,19(4): 235-238.[9] 符岩,翟秀静,王杰,等.添加稀土元素的锌基合金牺牲阳极的研究[J].稀土,2005,26(1): 49-52.[10] 王伟.海洋环境中微生物膜与金属电化学状态相关性研究.青岛:中国科学院海洋研究所,2003.29.[11] SCOTTO V, LAI M E. The ennoblement of stailess steels in seawater: a likely explanation coming from the field [J]. Corr Sci,1998,40(6):1007-1018.[12] 许凤玲.海洋生物膜的电活性及其在微生物燃料电池中的应用基础研究.青岛:中国科学院海洋研究所,2009.36-40.[13] WAN Yi, ZHANG Dun, LIU Huai-qun, et al. Influence of sulphate-reducing bacteria on environmental parameters and marine corrosion behavior of Q235 steel in aerobic conditions [J]. Electrochim Acta,2010, 55(5): 1528-1534.[14] CUI X Y, MARTIN D C. Electrochemical deposition and characterization of poly (3, 4-ethylenedioxythiophene) on neural microelectrode arrays [J]. Sens Actuators B: Chem,2003, 89(1-2):92-102.[15] 洪雪宝,林瑞木,李德楷,等.几种海洋附着生物对海洋用钢影响的电化学研究[J].海洋学报,1989,11(5):645-649.[16] 杜娟,李松梅,刘建华,等. A3钢在芽孢杆菌作用下的腐蚀行为[J]. 物理化学学报,2010,26(6): 1527-1534.[17] MA J, WEN J. The effects of lanthanum on microstructure and electrochemical properties of Al-Zn-In based sacrificial anode alloys[J]. Corrosion Science,2009, 51 (9): 2115-2119.[18] 邓正平. 表面处理渗氢浅谈[J].电镀与精饰,2000,22(2):33-34.[19] 马士德. 海洋微型生物与金属腐蚀关系的初步探讨.1979年腐蚀与防护学术报告会议论文集.北京: 科学出版社,1982. 376-380.