Biocorrosion induced by Sulfate-Reducing Bacteria on Stainless Steel – A Preliminary Study

304 stainless steel was tested under the media without Sulfate-reducing bacteria (SRB) and with SRB. The corrosion behaviors of 304 stainless steel in SRB and without SRB medium were studied by measuring the open circuit potential, the polarization curves and electrochemical impedance Spectrum,weight loss measurements to get the changes of fore-and-aft corrosion fouling. The open circuit potential shifted negatively with the time. The result showed that the slope of cathodic polarization curves measured in the medium included with SRB is lower than the one obtained in the medium without bacteria,while the slope of anodic polarization curves is higher than it. It is concluded that the process of anode polarization was repressed at the presence of SRB. With the growth of the culture time , the value of electrochemical impedance in the medium without bacteria reduced at first, then rose, while in the medium included with bacteria fell at all times. It indicated that SRB accelerated the corrosion of stainless steel. With the dipping time, a biofilm, under which corrosion products congregate to form local battery corrosion, was formed on the surface of stainless steel, so that the serious pitting corrosion is induced.