The objective determination of MIC (microbially influenced corrosion) can only take place through a combination of analysis methods and techniques. Only a visual inspection of the morphology of the defect is insufficient. In practice, this single line of evidence is often taken as basis for a diagnosis to determine whether MIC can be appointed as the main corrosion mechanism.
How often does MIC occur? That depends on who you ask. The GenoMIC project conducted research into pipeline failures and found that visual inspection was the main basis for diagnosing MIC. This visual inspection mainly looks at the external characteristics of the corrosion defect. What you are doing is that you will only look at the morphology of the defect.
MIC is characterised by pitting corrosion. Localised corrosion defects, of which the external features can differ considerably. Scientific research shows that this is not a good basis for determining MIC, but that you should use a multilayer approach, in which, in addition to these morphological characteristics, you should also use other methods to find evidence of the presence and activity of micro-organisms that indicate MIC.
In addition to morphology, one can think about using microscopic techniques, MMM (Molecular Microbiological Methods), metallurgical and mineralogical techniques.
We have developed an online masterclass to help you to recognise and properly diagnose MIC. Read more.