Corrosion Behavior of 316L Stainless Steel Influenced by Iron-reducing Bacteria Shewanella Algae Biofilms

Microbiologically influenced corrosion of 316L stainless steel(316LSS) by iron-reducing bacteria(IRB) Shewanella algae was investigated by means of open circuit potential(OCP)measurement, electrochemical impedance spectroscopy(EIS) and cyclic anodic polarization curves, and scanning electron microscopy and energy dispersive X-ray spectroscopy for characterization of corrosion products. The results showed that after immersion in the IRB containing solution the free corrosion potential of 316LSS shifted negatively; the polarization resistance of316LSS increased firstly, and then decreased; the presence of IRB reduced the hysteresis loop area of the cyclic anodic polarization curves and also the characteristic potential range of 316LSS,which indicated that IRB inhibited the initiation and propagation of pitting corrosion of 316LSS.The presence of IRB might be beneficial to the formation of biofilms on the surface of 316LSS exposed to in the solution, and therewith the chemical composition and property of the 316LSS surface might be changed by biofilms and metabolites, whilst which resulted in a stronger corrosion inhibition to the 316LSS immersed in the IRB containing solution.