Antwerp Corrosion & Fouling Meeting 2019 01-4-2019 [email protected]1 April 1, 2019, 2 nd international symposium on corrosion and fouling, Antwerp, Belgium Dr. Job Klijnstra +31 (0)6 10 49 00 59 Fouling control & material protection [email protected]Dr. Nanni Noël-Hermes +31 (0)6 46 84 72 96 MIC and biofilms [email protected]Microbial influenced corrosion (MIC) in maritime environment Corrosion, Failure analysis and Antifouling research since 1964 Former corrosion laboratory Royal Netherlands Navy Expertise Corrosion Electrochemistry Metallurgy Antifouling Microbiology Coating performance testing Material durability in seawater Natural seawater Outdoor exposure In-house laboratory of Royal Netherlands Navy a initiative ENDURANCE through RESEARCH
MIC is a rapid form of corrosion initiated or accelerated by microorganisms
Localized form of corrosion
Direct or indirect mechanism
Up to 20% of all serious corrosion events are related to MIC
It affects a wide diversity of industries such as maritime & offshore, water distribution and waste water treatment systems, oil and gas, food industry
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General facts about microorganisms:
Characteristics of microorganisms related to MIC: (Borenstein, 1994)
Other corrosion mechanisms are often not taken into account: Failure in the choice of a suitable mitigation strategy MO’s are found present but their activity is not established or investigated Often MIC is “blamed” when other explanations cannot be given
“Chicken or egg” question: what was first? Wrong choice/ failure of material/ no protection of material
or Presence and activity of microorganisms
MIC may take place regularly in conjunction with other corrosion mechanisms:
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Galvanic corrosion
Stray current
Under deposit corrosion
MIC diagnosis and failure analysis
1 Coatings: Correct choice of coating (part of structure, exposure conditions, lifetime, …) Proper application (surface pre-treatment and condition, equipment, ...) Difficult for mudline or area under seabed
Metallization (TSZ, TSA) seems to be promising but further investigations required, for instance in offshore wind
2. Cathodic protection: Depending on potential applied and maybe also on MO’s present Install and operate CP right from the beginning! Late installment and
interruptions may give problems
CP will probably work but optimal settings and conditions are still under investigation Cases are described in which biofilm formation was stimulated when using CP
3. Other mitigation strategies Biocides, corrosion inhibitors UV light, ultrasound
Chemicals often not possible in open systems; physical methods still under investigation
