Corrosion inhibition of stainless steel by a sulfate-reducing bacteria biofilm in seawater

Fu-shao Li 1,2) , Mao-zhong An 3) , and Dong-xia Duan 2) 1) School of Chemistry and Chemical Engineering, Qujing Normal University, Qujing 655011, China 2) State Key Laboratory for Marine Corrosion and Protection, Qingdao 266071, China 3) Chemical Engineering School, Harbin Institute of Technology, Harbin 150001, China

摘 要：Corrosion inhibition of stainless steel due to a sulfate-reducing bacteria （SRB） biofilm in seawater was studied. By atomic force microscopy, a layer of fish-scale-like biofilm was found to form as stainless steel coupons were exposed to the culture media with SRB, and this biofilm grew more and more compact. As a result, coupons’ surface under the biofilm turned irregular less slowly than that exposed to the sterilized culture media. Then, physicoelectric characteristics of the electrode/biofilm/solution interface were investigated by electrochemical impedance spectroscopy （EIS）, and the coverage of the biofilm as well as the relative irregularity of coupons’ surface was also recorded by EIS spectra. Finally, anodic cyclic polarization results further demonstrated the protective property of the biofilm. Therefore, in estimation of SRB-implicated corrosion of stainless steel, not only the detrimental SRB metabolites but also the protective SRB biofilm as well should be taken into account.

关键词：