电弧喷涂Zn和Al涂层在含SRB海水中的腐蚀行为与机理  

Corrosion behavior and mechanism of arc-sprayed Zn and Al coating in seawater with SRB

作　　者：高文文[1] 吴玉萍[1] 段继周[2] 洪晟[1] 王博[1] 

机构地区：[1]河海大学力学与材料学院,江苏南京210098 [2]中国科学院海洋研究所,山东青岛266071

出　　处：《材料热处理学报》2014年第3期193-199,共7页Transactions of Materials and Heat Treatment

基　　金：国家海洋局海洋可再生能源专项资金项目(GHME2011CX02)

摘　　要：利用电弧喷涂技术在Q235钢基体上分别制备了Zn、Al涂层,研究涂层在含硫酸盐还原菌(SRB)海水中的腐蚀行为与机理。采用EIS、PC等电化学方法研究Zn、Al涂层在SRB一个生长周期内的腐蚀电化学行为,采用SEM和EDS对浸泡15 d后的涂层表面微观形貌和化学成分进行分析。EIS和PC结果表明,Zn、Al涂层在含SRB海水中的腐蚀速率均表现出先增大后减小的趋势,在整个实验过程中,Zn涂层的腐蚀速率一直大于Al涂层;SEM分析表明,浸泡结束后,Zn涂层表面覆盖了一层由微生物(SRB)和腐蚀产物共同组成的混合膜层,而铝涂层表面的覆盖层主要为生物膜,腐蚀产物较少。EDS结果显示,Zn涂层表面的S元素含量远高于Al涂层,说明SRB的代谢活动对Zn涂层的影响相对较大。The corrosion behavior and mechanism of pure Zn and pure A1 coatings fabricated by arc spraying on Q235 steel were studied in seawater with sulfate-reducing bacteria （SRB） using circuit potential monitoring, electrochemical impedance spectroscopy （EIS）, polarization curve （PC） , scanning electron microscopy （SEM） and energy dispersive spectroscopy（EDS）. The results of EIS and PC show that the corrosion rate of both Zn coating and AI coating is first increases and then decreases, and the corrosion rate of Zn coating is significantly greater than that of A1 coating during the whole experiment process. After immersion for fifteen days in seawater with SRB, SEM images show that Zn coating surface formed a thick mixed layer of corrosion product and microorganism, while the coverage layer of AI coating surface is mainly biofilm and the corrosion product is rare. EDS analysis shows that the concentration of S element in the Zn coating surface is much more than that of AI coating, which suggests the effect of metabolism activity of SRB on Zn coating is stronger.

关 键 词：硫酸盐还原菌 电弧喷涂 涂层 电化学 腐蚀 

分 类 号：TG174.44[金属学及工艺—金属表面处理]