海洋环境下金属材料微生物腐蚀研究进展

海洋环境下的微生物易附着在金属材料表面形成生物膜,进而导致金属材料表面的微生物腐蚀(MIC)。分析了海洋环境下常见的易导致腐蚀的微生物种类及其特征,如硫酸盐还原菌(SRB)、铁氧化细菌(IOB)、产酸菌(APB)与产粘液菌(SPB)等,归纳了船舶与海洋平台涉及的微生物腐蚀及其与材料摩擦磨损的协同作用。在此基础上,重点综述了近年来碳钢、不锈钢与铜合金在海洋环境下的微生物腐蚀研究进展,包括溶解氧(DO)浓度、胞外聚合物(EPS)、生物膜微观形态等因素对碳钢MIC的影响,不锈钢在MIC过程中钝化膜与Cr元素化合物形态与含量变化,微生物抵抗Cu离子毒性机制以及铜合金在MIC过程中出现的脱合金成分腐蚀。对比了碳钢、不锈钢与铜合金表面在MIC中由生物膜、腐蚀产物与钝化膜形成的复合表面层结构差异。并从阴极去极化理论与微生物电化学腐蚀理论的角度解释了MIC,总结了两种理论间的关联性与局限性,指出了一些亟待解决的问题。

Research Progress on Microbiological Induced Corrosion of Metallic Materials under Ocean Environment

Microorganisms attached on surfaces of metallic materials are easy to form biofilms under ocean environment and then result in microbiological induced corrosion (MIC). Typical species and traits of corrosive microorganisms under ocean environment such as sulfate-reducing bacteria (SRB), iron-oxidizing bacteria (IOB), acid-producing bacteria (APB) and slime-producing bacteria (SPB) were analyzed and then the synergistic effect between the microbiological induced corrosion involved in marine vessels and platforms and the material friction wear was explained. Accordingly, the recent research progress of MIC under ocean environment in terms of carbon steel, stainless steel and copper alloy was summarized, including the effects of concentration of dissolved oxygen (DO), extracellular polymeric substances (EPS) and biofilm micromorphology on the MIC of carbon steel, the morphological and content changes of the passive film and Cr element in the MIC process, and microorganic resistance against toxicity of Cu ion as well as de-alloying corrosion in MIC. Meanwhile, the structural difference of composite surface layer on carbon steel, stainless steel and copper alloy surface resulted from biofilm, corrosion products and passivity in MIC was compared. Lastly, MIC was explained from the perspectives of cathodic depolarization theory and electrochemical microbially influenced corrosion theory. The relationship and limitations between the two theories were summarized, and some imperative problems to be solved were proposed and presented.