Q235钢在海洋铁细菌作用下的腐蚀行为研究

Research on corrosion behavior of Q235 steel in marine iron-oxidizing bacteria

采用开路电位、电化学极化曲线、电化学阻抗谱(EIS)等方法研究了海洋铁细菌作用下Q235钢的腐蚀行为与腐蚀机理。扫描电子显微镜(SEM)形貌分析结果表明有大量的杆状铁细菌附在Q235钢铁表面。在海洋微生物的影响下,Q235钢的开路电位变小,腐蚀倾向与腐蚀率变大。EIS结果表明在海洋铁细菌作用下Q235钢的交流阻抗模值减少,而且大大降低了Q235钢的极化电阻和表面膜的电阻。微生物的附着促进了钢材表面的溶解,使其表面氧化膜层消失,进而形成了疏松不致密的生物膜层,从而加速了其腐蚀进程。

This article studied the corrosion behavior and corrosion mechanism of marine iron-oxidizing bacteria on Q235 steel by using open circuit potential analysis, polarization curves and electrochemical impedance spectroscopy （EIS） etc. The scanning electron microscope （SEM）showed that the large rod-shaped microbial colonies distributed on the surface of Q235 steel materials. The presence of bacteria greatly reduced the open circuit potential of the materials, and made the corrosion tendency of Q235 steel become large. The EIS analysis resuhs showed that the activities of bacteria reduced the value of AC impedance, and made polarization resistance and surface film resistance polarization resistance decreased. The adherence of microorganisms on the material surface promoted the surface layer to dissolution and made the oxide film of steel disappear,instead of, more loose biofilm formed, that accelerated the corrosion process.