天然海水中微生物膜对316L不锈钢腐蚀行为研究

采用电化学技术包括开路电位、电化学阻抗谱、动电位极化、循环极化、表面表征技术、包括扫描电镜和能谱分析研究了316L不锈钢在天然海水中微生物膜影响的初期腐蚀行为。研究表明,海洋微生物在不锈钢表面发生附着形成生物膜。在天然海水中不锈钢的开路电位正移约450mV,而在灭菌海水中不锈钢的开路电位基本保持不变。电化学阻抗和极化实验结果指出,海洋微生物膜使不锈钢阻抗增加,点蚀电位升高,生物膜抑制了不锈钢的腐蚀发生。这种抑制作用经历了一个先变大后减小的过程。天然海水中,海洋生物膜的附着和其代谢产物作用使不锈钢的耐蚀性能得到提高,这一耐蚀性能的提高与生物膜影响的阳极抑制作用有关。     

用丝束电极研究SRB微生物诱导腐蚀的电化学特征

应用丝束电极研究了半连续培养基中SRB及其生物膜对Q235低碳钢腐蚀的影响，采用电位、电流以及阻抗扫描技术测试了生物膜的不均匀性特性，以及电极开路电位和电化学阻抗谱（EIS）与培养时间的关系，发现微生物膜的成长，开路电位负移，由于生物膜中SRB代谢产生的硫化物具有导电性，使表面电位扫描已不能作为生物膜下局部腐蚀的判据，但表面阻抗扫描却可探测到膜下的局部腐蚀，EIS表明，生物膜电容极大（10^4－10^5μF／cm^2），且膜电容随时间呈S型增加，而溶液电阻和电荷传递电阻则呈指数下降。     

厌氧微生物对紫铜腐蚀行为的影响

采用开路电位、电化学极化曲线、电化学阻抗谱(EIS)研究了紫铜在海洋厌氧菌影响下的腐蚀行为。结果表明,扫描电子显微镜SEM形貌分析结果表明在紫铜上附着的SRB海洋微生物呈微弯杆状,材料表面形成较致密的半透明的生物细菌膜。电化学测试结果表明,紫铜在SRB细菌培养基海水中的腐蚀过程主要受活化极化控制,SRB微生物的存在导致紫铜的开路电位和活化极化率变小,从而加速了紫铜的腐蚀进程。     

316L不钢在回用污水培养微生物介质中的腐蚀行为锈

采用电化学方法研究了316L不锈钢材料在经三级处理以后的回用污水培养的微生物介质中的腐蚀行为。结果表明，不锈钢电极在回用污水接种的培养基介质中的自腐蚀电位较纯培养基介质中明显负移，阳极极化电流大于纯培养基介质中不锈钢电极的阳极极化电流，含菌培养基中不锈钢的电化学阻抗值小于相应的无菌培养基中的电化学阻抗值，这表明回用污水中的微生物对不锈钢材料的腐蚀起到促进作用。     

磁场作用下的微生物腐蚀研究进展

磁体周围存在磁场,磁体间的相互作用就是以磁场作为媒介的,磁场力包括洛伦兹力和安培力.概述了磁场对微生物和金属腐蚀过程的影响,包括对单一细菌和混菌体系、电化学控制和浓差极化控制的电化学过程的影响.归纳了磁场作用于微生物金属腐蚀的防控方法,包括微生物竞争手段、缓蚀杀菌剂的应用以及存在的不足等问题.在此基础上,重点综述了近年来磁场条件下金属微生物腐蚀的研究进展,分析了磁场对于微生物生长特性和生物膜形成的影响,分别以不同微生物存在的体系、电化学过程控制的类型等方面展开详细讨论.针对磁场存在的环境,总结了微生物对金属的腐蚀机理,包括生物膜理论、离子干涉理论、自由基理论等.最后结合磁场对金属腐蚀过程的相关机理,展望了后续磁场对微生物腐蚀防控的研究方向.     

316L不锈钢在回用污水培养微生物介质中的腐蚀行为

采用电化学方法研究了316L不锈钢材料在经三级处理以后的回用污水培养的微生物介质中的腐蚀行为。结果表明,不锈钢电极在回用污水接种的培养基介质中的自腐蚀电位较纯培养基介质中明显负移,阳极极化电流大于纯培养基介质中不锈钢电极的阳极极化电流,含菌培养基中不锈钢的电化学阻抗值小于相应的无菌培养基中的电化学阻抗值,这表明回用污水中的微生物对不锈钢材料的腐蚀起到促进作用。     

天然海水微生物对5083铝合金初期腐蚀行为的影响

利用荧光电子显微镜,扫描电镜及能谱表面分析技术和开路电位,电化学阻抗谱,动电位极化电化学技术研究了在天然海水中浸泡初期,天然海水微生物对5083铝合金腐蚀行为的影响.结果表明,在天然海水中,铝合金表面形成良好的生物膜.电化学结果表明,在天然海水中铝合金腐蚀电位负移,点蚀电位正移,电荷转移电阻增大,说明短期浸泡时,天然海水生物膜的形成可以抑制其腐蚀,尤其对点蚀具有明显的抑制作用.在无菌海水中,随时间的增长,铝合金的腐蚀也受到一定程度的抑制,原因是锈蚀产物的形成对铝合金具有一定的保护作用.     

铁还原细菌Shewanella algae生物膜对316L不锈钢腐蚀行为的影响

通过电化学阻抗谱、环阳极极化、扫描电镜和X射线能谱等方法研究了铁还原细菌Shewanella algae对316L不锈钢腐蚀行为的影响。电化学结果表明,Shewanella algae使不锈钢的腐蚀电位发生负移;在含该细菌的介质中,不锈钢表面的阻抗值先增大后减小,在第4 d达到最大,是初始阻抗值的260倍;不锈钢在无菌介质中的滞后环面积和特征电位区间(击穿电位与保护电位之差)小于其在有菌介质中的滞后环面积和特征电位区间,说明Shewanella algae对不锈钢点蚀的发生与发展起到抑制作用。观察到不锈钢表面为生物膜所覆盖,生物膜及代谢产物改变了不锈钢表面的元素组成和化学性质。从微生物膜氧消耗和电活性生物膜的角度,初步提出了Shewanella algae的腐蚀抑制机理。     

AFM技术在微生物腐蚀研究中的应用

介绍了原子力显微镜(AFM)的工作原理、操作模式以 及在微生物腐蚀研究中的应用,包括原位观察细菌和微生物膜形貌、测量力-距离曲线研究微生物在材料表面的粘附力、测量材料表面电位的不同得知生物膜厚度和腐蚀程度.同时还介绍了电化学原子力显微镜的应用.     

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。     

The use of electrochemical techniques for the investigation and monitoring of microbiologically influenced corrosion and its inhibition – a review

The background of several electrochemical techniques – recording of the corrosion potential E_corr, electrochemical impedance spectroscopy (EIS), electrochemical noise analysis (ENA) and recording of potentiodynamic polarization curves – has been discussed and examples of the use of these techniques in studies of microbiologically influenced corrosion (MIC) and MIC inhibition have been presented. These examples range from the use of the polarization resistance R_p and the noise resistance R_n in corrosion monitoring in a sewer environment and a gas production field, respectively, to the application of EIS and ENA in the evaluation of the interaction of bacteria with protective coatings on steel exposed to natural seawater (NS). A more detailed analysis based on EIS and ENA of Corrosion protection of Al 2024, mild steel and brass in artificial seawater (AS) by bacteria such as B. subtilis, B. licheniformis, E. coli and Shewanella has been presented. Determination of the changes of R_p and R_n as well as E_corr allows to propose appropriate mechanisms of MIC inhibition. These mechanisms have been confirmed in the case of S. algae by recording of anodic and cathodic potentiodynamic polarization curves after exposure to AS containing the bacteria for extended time periods.     

Comparison of electrochemical techniques during the corrosion of X52 pipeline steel in the presence of sulfate reducing bacteria (SRB)

This work compares three electrochemical techniques, linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN), used in the study of corrosion of X52 steel samples in an environment containing a culture of sulfate reducing bacteria (SRB). The study emphasizes the different electrochemical information obtained when using these techniques in microbiologically influenced corrosion (MIC) studies.     

Sophisticated Electrochemical methods for MIC investigation and monitoring

Due to the electrochemical nature of MIC electrochemical methods are useful tools to study reactions at the metal/biofilm interface, investigate MIC mechanisms and monitor the onset of MIC and its propagation. The paper discusses various electrochemical methods—measurement of corrosion potential, redox potential, polarization resistance, galvanic currents, large signal polarization techniques, random potential pulse method, electrochemical impedance spectrometry, electrochemical relaxation methods (programmed pulse relaxation, sinusoidal ac relaxation), electrochemical noise analysis, scanning vibrating electrode techniques (Kelvin probe, vibrating microreference electrode, electrochemical sensors)–;with respect to their applicability and merits for MIC investigations and monitoring.     

Electrochemical techniques used in MIC studies

This paper presents a review of the application of electrochemical techniques in studying the microbially influenced corrosion (MIC) process of metals and their alloys. Some electrochemical techniques used in microbiology and biofilm study are discussed as well as some classic electrochemical techniques, such as corrosion potential, redox potential, polarization curves, electrochemical impedance spectroscopy, electrochemical noise and microelectrode techniques. Electrochemical quartz crystal microbalance (EQCM) which is seldom used in MIC study is also discussed.     

Corrosion of API XL 52 steel in presence of Clostridium celerecrescens

During the characterization of sediments formed in pipelines transporting hydrocarbons, the knowledge of the microbiological diversity becomes very interesting, especially when it is related to microbiologically influenced corrosion (MIC). The presence of microorganisms is considered as one of the factors that affect the corrosion processes occurring at the pipeline; therefore, their corrosiveness must be determined. In this way, the identification of new species affecting the MIC processes is still considered relevant. In this work, the effect of Clostridium celerecrescens upon the corrosion of API KL 52 steel was evaluated. This microorganism was isolated and identified from the sediments collected during the inner cleaning procedures of a gas pipeline. The polarization resistance (PR) and electrochemical impedance spectroscopy (EIS) techniques were considered to estimate the microorganism behavior during the corrosion process. The results were complemented with a metal surface analysis, using a scanning electron microscope (SEM). The resistance values induced by the presence of the microorganisms clearly indicated that C. celerecrescens has an effect on the corrosion process occurring at the API XL 52 steel surface.     

Corrosion Behavior of Mild Carbon Steel in Ethanolic Solutions

Electrochemical evaluation of ASTM A36 steel was performed in ethanolic solutions containing small concentrations of water ranging from 0 to 10 vol.%. Electrochemical techniques such as open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization were utilized to analyze corrosion parameters. A fixed concentration of chloride, as per the ASTM specification for fuel grade ethanol, was added to increase the conductivity of the solutions. The effects of water and oxygen on the corrosion behavior of steel in these solutions have been discussed. Pitting corrosion of the steel specimens in these solutions was evaluated using scanning electron microscopy (SEM) and pitting analysis. This investigation was performed to establish a baseline for the microbiologically influenced corrosion (MIC) of steel in ethanolic solutions.     

Electrochemical behavior of microbiologically influenced corrosion on Fe3Al in marine environment

In this article, microbiologically influenced corrosion behavior of Fe₃Al intermetallic compound in microorganism culture medium has been investigated by using weight loss methods, electrochemical techniques, and electron microscopy. Polarization curves showed that a sharp electrical current peak caused by surface pitting could be observed after Fe₃Al electrodes were immersed in culture medium for 15 days when the polarization potential was about -790 mV vs SCE. Based on the electrochemical impedance spectroscopy (EIS) and the equivalent circuit parameters of the associated system, the corrosion products were found to exhibit a two-layer structured feature and the microorganisms could induce pitting and erosion corrosion of the inner layer. In addition, the passivating film of the inner layer was absolutely destroyed by microbial metabolic products.     

电弧喷涂Al-Zn-Si-RE合金涂层在3.5%NaCl溶液中的电化学腐蚀行为(英文)

采用电弧喷涂方法在低碳钢表面获得高铝含量的Al-Zn-Si-RE涂层。通过测量Al-Zn-Si-RE涂层在3.5%NaCl溶液中的动电位极化曲线,腐蚀电位-时间曲线和电化学阻抗谱,系统地研究涂层的电化学腐蚀行为。通过将测量电化学阻抗谱拟合成等效电路图,研究涂层在3.5%NaCl溶液中浸泡不同时间的阻抗行为。结果表明:Al-Zn-Si-RE涂层与Zn-15Al涂层具有相似的极化行为,阳极极化曲线均无钝化特征,仅呈现出活性溶解,但其腐蚀性能优于Zn-15Al涂层。Al-Zn-Si-RE涂层可以给钢基体提供有效的牺牲阳极保护作用,且牺牲阳极保护作用在涂层腐蚀过程中占主导地位。此外,腐蚀电位-时间曲线和电化学阻抗谱结果表明:在浸泡过程中存在点蚀-溶解-再沉积、活化溶解、阴极保护、腐蚀产物引起的物理屏蔽和涂层失效五个腐蚀阶段。     

不同晶粒尺寸的Cu-40Ni合金在酸性介质中的耐蚀性能

采用电弧熔炼(CA)和机械合金化(MA)通过热压烧结工艺制备了晶粒尺寸差别较大的Cu-40Ni合金,借助于PARM273A和M5210电化学综合测量仪,利用动电位扫描法和交流阻抗技术对比研究了上述合金在酸性介质中的腐蚀电化学性能以及腐蚀机理。结果表明:随着H 浓度的增加,CA Cu-40Ni合金的自腐蚀电位负移,而MA Cu-40Ni合金则正移,两种合金的动电位扫描极化曲线均未出现钝化现象;随着H 浓度的增加,CA Cu-40Ni合金的极化电阻增大,腐蚀电流减小,合金的耐蚀性能增加,而MA Cu-40Ni合金的极化电阻减小,腐蚀电流增加,合金的耐蚀性能降低。两种合金的交流阻抗谱均由双容抗弧组成,腐蚀过程受电化学反应控制。晶粒细化后,合金中存在大量晶界,参与腐蚀反应的活性原子数增加,促使MA Cu-40Ni合金的腐蚀速度高于CA Cu-40Ni合金。