炼油厂冷却水系统硫酸盐还原菌对316L不锈钢点腐蚀的研究

用开路电位、动电位扫描、电化学阻抗技术和扫描电镜等方法，研究了316L不锈钢在硫酸盐还原菌(SRB)溶液中的腐蚀电化学行为，分析了炼油厂冷却水系统微生物腐蚀的特征及机制.结果表明，在含有SRB溶液中的自腐蚀电位(Ecorr)和点蚀电位(Epit)随浸泡时间的增加而负移，极化电阻(Rp)随浸泡时间的增加而减小；在含有SRB溶液中的腐蚀速率均大于在无菌溶液中；SRB的生长代谢活动影响了316L SS表面的腐蚀过程，使不锈钢表面的钝化膜层腐蚀破坏程度增加，加速了316L SS的腐蚀.

INVESTIGATION OF SULFATE-REDUCING BACTERIA ON PITTING OF 316L STAINLESS STEEL IN COOLING WATER SYSTEM FOR OIL REFINERY

Microbiological induced pitting corrosion on 316L stainless steel used in water cooling system for oil refinery was analyzed,the electrochemical features on pitting of stainless steel in sulphate-reducing bacteria (SRB)media were investigated by using of open circuit potential measure、potentiodynamic scanning、electrochemical impedance spectrum (EIS)and scanning electron microscopy(SEM).With prolonging the immersion time,the corrosion potentia l and pitting potential decreased,and polarization resistance (Rp)decreased as well.The corrosion rate of 316L SS in SRB medium is larger than those in sterile medium.The experimental results showed that the metabolic activity of SRB influenced the corrosion process,increased the corrosion damage degree of the passive film,accelerated the corrosion rate of 316L SS with the increase of immersion time.