Corrosion of Carbon Steel Induced by SulfateReducing Bacteria in Anaerobic Soil

Abstract

Microbiologically influenced corrosion (MIC) of carbon steel in soil environments was investigated at field and laboratory. MIC is very severe corrosion and it is not easy to distinguish this corrosion from inorganic corrosion because of its localized, pitting-type character. Therefore, it is important to provide proper assessment techniques for the prediction, detection, monitoring and mitigation of MIC. It is possible to predict the MIC risk, i.e., the activity of sulfate-reducing bacteria (SRB) through the analysis of soil environments. Chemical, microbiological and surface analysis of corrosion products and metal attacked could reveal the possibility of the occurrence of MIC. Various electrochemical and surface analysis techniques could be used for the study of MIC. Among these techniques, thin-film electrical resistance (ER) type sensors are promising to obtain localized corrosion rate of MIC induced by SRB. It is also important to study the effect of cathodic protection (CP) on the MIC. In case of coated pipeline, the relationship between coating disbondment and the activity of SRB beneath the disbanded coating is also important.