海水微生物对Zn-Al-Cd牺牲阳极腐蚀性能的影响  

Effects of Microorganism on Corrosion of Zn-Al-Cd Sacrificial Anode in Natural Seawater

作　　者：宋秀霞[1,2] 张杰[2] 杨东方[1] 段继周[2] 

机构地区：[1]上海海洋大学水产与生命学院,上海201306 [2]中国科学院海洋研究所,山东青岛266071

出　　处：《材料工程》2013年第1期58-63,共6页Journal of Materials Engineering

基　　金：国家自然科学基金资助项目(41006054);中国科学院知识创新工程重要方向项目(KZCX2-EW-205)

摘　　要：通过电化学阻抗(EIS)、扫描电镜(SEM)和荧光显微镜技术等方法对Zn-Al-Cd牺牲阳极在灭菌和天然海水中的腐蚀行为进行了对比研究。结果表明:在实验前期,试样在天然海水中的腐蚀电位高于灭菌海水中的腐蚀电位,在实验后期,结果相反。EIS测试结果表明,灭菌海水中试样的Rct值要比天然海水中试样小很多,原因是在天然海水中,试样表面附着的细菌通过代谢活动形成一层生物膜,在一定程度减缓了试样的腐蚀速率。SEM结果表明,灭菌海水中的试样表面发生了局部腐蚀,而在天然海水中试样的腐蚀较均匀。荧光显微镜结果表明:细菌先是在试样上以单体形式附着,然后形成局部的团聚,进而形成生物膜,随着营养物质的耗尽,生物膜最后从试样表面脱落。The effects of the sterile seawater and natural seawater on corrosion of Zn-A1-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 experi- ment, but at the late of experiment, the result is opposite. The EIS results show that the Rctvalue 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 mi- croscopy 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.

关 键 词：Zn-Al—Cd阳极 海水 电化学阻抗谱 荧光显微镜技术 

分 类 号：TG171[金属学及工艺—金属表面处理]