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Surface coating

  1. Sep 27, 2011 #1
    Is Passivation to s/s = to Zinc Clear Coating of s/s?

    I know passivation is adding a layer of chorosion inhibtor the the surface so can this layer be clear zinc or are these different means of coating s/s?
  2. jcsd
  3. Sep 27, 2011 #2


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    Gold Member

    Stainless steel is stainless because it has a layer of oxygen molecules at the surface. These form naturally during maching processes. Passivation (typically in nitric acid) makes the oxygen layer thicker and, therefore, more resilient.

    Zinc works differently. I have never heard of zinc plating on stainless, but on regular steel it forms a sacrificial anode. It doesn't even need to be plated for this to work, a lump of zinc near a steel propellor on a boat for instance will corrode in preference to the propellor.

    I am sure someone will be able to provide a more technical explanation than mine. In the meantime here are some wikilinks.
    http://en.wikipedia.org/wiki/Passivation" [Broken]
    http://en.wikipedia.org/wiki/Galvanic_anode" [Broken]
    Last edited by a moderator: May 5, 2017
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