Q:
What is Microbiologically
Influenced Corrosion (MIC)?





A:
  • During the past ten years or so, there has been a growing
    appreciation for the effects of microbiologically influenced
    corrosion.

  • An excellent reference work is the "Microbiologically
    Influenced Corrosion Handbook
    " by S. W. Borenstein, P.E.
    Industrial Press, Inc. 1994. ISBN 0-8311-3056-3.(You can
    learn more about Ms. Borenstein
    here).

  • Both salt water and fresh water.

  • Nuclear plants, chemical process plants,
    pulp and paper mills.

  • Stainless steels and aluminum alloys are
    susceptible in general.

  • Weldments in aluminum and steel structures
    are particular targets.

  • Concrete structures are also targets.

  • Crown corrosion in a concrete sewer is illustrated
    below. Anaerobic chemoheterotrophs produce H2S, which
    is absorbed in condensate on the walls above the water
    line.

  • Aerobic chemolithotrophs oxidize the reduced sulphur to
    SO4, forming H2SO4, which attacks and erodes the concrete,
    often to the point of structural failure.