College of Marine Studies, University of Delaware, Lewes, DE
Pages: 14 Published: Jan 2005
THERE IS NO SINGLE, unique microbiological environment. Rather, the microscopic organisms present in all natural aqueous (and many artificial) environments should be regarded as having a potential influence on any corrosion reaction that takes place in that environment. Theoretically, that influence can range, as shown in Fig. 1, anywhere from the organisms being the sole causative agent for corrosion, to innocent bystanders having no influence on corrosion, to corrosion inhibitors. In practice, when the influence of the organisms is a significant factor in determining the overall rate and extent of corrosion, that influence will usually make the corrosion more localized, and the penetration rate higher, than it would be in a sterile environment with the same chemistry. In such cases the corrosion is often referred to as “microbiologically influenced corrosion,” or MIC. As of late 2001, a significant influence of microorganisms has been reported on uniform corrosion of a variety of materials in both aerated (aerobic) and deaerated (anaerobic) environments [1,2], pitting and crevice corrosion [3-8], corrosion fatigue , galvanic corrosion [10,11] and cathodic protection [12,13]. Effects have also been reported on cracking and embrittlement related to hydrogen evolution . For additional general information on various types of microbiologically influenced corrosion the reader is referred to the books by Borenstein , Gaylarde and Videla , Kobrin , Stoecker  and Videla  as well as a conference proceedings edited by Angel, et al. .
Paper ID: MNL11049M