Microbiologically Influenced Corrosion

When a metal is exposed to natural waters, corrosion begins immediately. In some cases, microorganisms influence the corrosions process. The corrosion of the metal and the composition of the corrosion deposits largely depend on :

1. microbiology
2. Metallurgy
3. Electrochemistry
4. Bulk water chemistry

Microbiology is a factor in terms of environmental variables and the activity of the organisms, metallurgy is key factor, given the many variables, such as the type, structure and processing of the metal and electrochemistry is essential because of the mechanisms by which the corrosion processes occur. For example, the metal goes intro solution as ion, and solid products, such as rust, form by a subsequent reaction. Not all corrosion is MIC. Resolving, understanding and mitigating MIC problems require familiarity with all four fields : microbiology, metallurgy, electrochemistry and water chemistry.

source : corrosion handbook