红壤浸出液中X100管线钢微生物腐蚀特征

Characteristics of Microbiologically Induced Corrosion of X100 Pipeline Steel in Red Soil Extract Solution

采用开路电位、线性极化曲线和阻抗谱等电化学手段,结合扫描电子显微镜研究了酸性红壤浸出液中硫酸盐还原菌对X100管线钢腐蚀的影响。研究结果如下:实验初期硫酸盐还原菌的存在降低了管线钢的自腐蚀电位,增加了管线钢腐蚀敏感性,促进了X100管线钢的腐蚀;实验中后期硫酸盐还原菌的生理活动改变了溶液中和X100管线钢表面的化学、电化学状态,抑制了腐蚀;硫酸盐还原菌的生理活动升高了酸性土壤浸出液的pH值,改变了X100管线钢表面膜层的结构,结合层出现了韦伯扩散,阻碍了腐蚀产物的扩散。

Effect of sulphate-reducing bacteria （SRB） on corrosion of pipeline X100 steel in acidic red soil extract solution was investigated using linear polarization technique, electrochemical impedance spectroscopy （EIS） and scanning electron microscope （SEM）. SRB tends to accelerate corrosion of pipeline X100 steel in initial stage of the experiment, while to inhibit corrosion at the end of experiment. The physiological activity of SRB may alter the pH of acidic red soil extract solution and chemical and electrochemical state of the surface of pipeline X100 steel. What＇ s more, a product layer was detected on the surface of pipeline X100 steel in inoculated environment, which may lead to the Weber impedance.