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Corrosion by air

  1. Sep 18, 2009 #1
    Hi all, just a quick question, I saw some of the carbon steel pipes which are used to tranpsort compressed air are corroded, when i ask, people told me that the corrosion was caused by the air. Is it the moisture in the air which causes the corrosion, or can the air pressure (sorry, can't remember the pressure in that pipe) within the pipe actually 'sheave' some of the pipe materials off?

  2. jcsd
  3. Sep 18, 2009 #2


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    It's going to be because of the moisture content in the compressed air. In compressed air systems, water content is a huge problem that is usually overlooked and not dealt with properly because it can be expensive to handle. Pressure by itself can cause fatigue issues, but not corrosion.
  4. Sep 19, 2009 #3
    unpopular idea
    rust is caused by life
    life needs water
    rust needs water

    iron in a water free environment [ deserts]
    doesNOT rust

    rust grows in shapes that look very much like
    the growth of micro-organismic life in a petri dish
  5. Sep 21, 2009 #4
    similar to the "biofilm" that degrades plastic?

    I am intrigued, and must ponder....hhmmmmm

  6. Sep 21, 2009 #5


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    Maybe, however:
    a) There's still plenty of bacteria in dryer environments
    b) If you heat pasteurize or gamma irradiate a sample of iron in water (thus killing all the bacteria), it'll still rust.

    EDIT: Not to say that 'life' isn't going to accelerate corrosion (unless it actually does the opposite and builds up a layer that prevents moisture / oxygen from getting through), but life isn't going to supply moisture out of nowhere.
  7. Sep 29, 2009 #6
    rust is caused by electrochemical corrosion.
  8. Oct 4, 2009 #7
    Thanks for the input guys! :)
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