MIC OF STEELS BY IRON REDUCING BACTERIA

摘要

Sulfate reducing bacteria (SRB) are generally recognized as the most destructive agents in microbiologically influenced corrosion (MIC) of steer under anaerobic conditions. However, other bacteria with different physiological properties are also considered to play roles in corrosion processes. These include the iron reducing bacteria (IRB), or "iron reducers", which reduce ferric ion to ferrous ion in anaerobic environments. The role and importance of IRB in MIC has been a matter of controversy. Some work indicate that they are directly important in causing or enhancing corrosion, while other work show that iron reducers may actually confer protection against biotic or abiotic aggressive agents. In this work we are giving two examples on the role of IRB in corrosion of carbon steel in chloride containing media: one is a laboratory case involving a marine vibrio (Vibrio alginolyticus) and SRB and the other is a field case in a water injection line of an oil platform located in the Gulf of Mexico where the IRB (Shewanella and Vibrio) are growing in biofilms with SRB and other marine bacteria.