Integration of State-of-the-Art Methods for Assessing Possible Failures due to Microbiologically Influenced Corrosion

Microbiologically Influenced Corrosion (MIC) is a complex form of corrosion caused by the activity of microorganisms such as bacteria, archaea and fungi. It is typically characterized by the presence of microbial populations within a biofilm or semi-solid deposit resulting in localized and accelerated corrosion. Compared to other corrosion threats, however, MIC can be quite complex requiring multi-disciplinary approaches in its assessment. In this presentation, a new approach to undertake investigations of suspected MIC failures is proposed. This methodology was developed through a review of the available literature, case studies, and expert solicitation. The failure mechanism is evaluated using multiple lines of evidence including service history, operational parameters, chemical assessment, and microbiological analyses based on Molecular Microbiological Methods (MMM). A failure assessment checklist was developed to assist and guide investigators in confirming MIC as a probable cause of failure. Special considerations such as component preservation and sampling methods are also presented. This new checklist assists practitioners in assessing MIC failures, and is complimentary to existing protocols used for other corrosion mechanisms and failure modes.