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Galvanic corrosion
hautsteel -
Sunday, November 8, 2009 - 10:28am
copper | corrosion | stainless steel I am working on a concept for an outdoor garden gate. It would involve layering and alternating sheets of stainless and copper or brass with areas cut out in order to achieve a specific variegated pattern. I am aware that galvanic corrosion can occur between copper and mild steel, but am not certain about the potential chemical interactions arising from stainless being in direct contact with copper or brass... Can someone more well versed in metallurgy please advise? Thanks! Dino  Hi STEF, I am sorry if my
hautsteel -
Friday, November 13, 2009 - 9:32am
Hi STEF, I am sorry if my explanation was a bit confusing. A few years ago I built an awning (as per the designers specifications), comprised of a steel structure supporting a copper roof riveted to the steel (yes - it is still one piece for now). However, in this case I don't intend to have the copper come in contact with the steel - only copper/stainless and brass/bronze will be in contact. I read up a bit on the galvanic corrosion process and learned that it can occur when two dissimilar metals are in contact within the presence of an electrolyte, e.g. water, sea water, etc. The less noble metal (in this case the copper) can become the anode and will tend to corrode at an accelerated rate, while the more noble of the two metals (in this case the stainless) becomes the cathode and will tend to corrode more slowly. I also found a good example of galvanic current flow; that is the fruit powered electronic clock. When a copper (cathode) and zinc (anode) electrode are placed in the acidic electrolyte of a grapefruit, a galvanic current (enough to power a digital clock) is created. Dino  Copper and stainless are
Rich Waugh -
Thursday, November 12, 2009 - 7:25pm
Copper and stainless are pretty much fine together - look at the myriad pieces of copper/stainless cookware out there. Rich Hello Rich, I have
hautsteel -
Friday, November 13, 2009 - 9:35am
Hello Rich, I have overlooked the obvious once again - LOL! Dino Yeah, the number of times
Rich Waugh -
Friday, November 13, 2009 - 10:27am
Yeah, the number of times I've overlooked the obvious is beyond count at this point in my life! That's what friends are for, right? Rich |
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ArtMetal
galvanic corrosion
Dino,
I don't know about the stainless yet. What are you going to do to prenvent the corrosion between the mild steel and copper. Are you going to coat part of the copper, it being the more noble metal. I would think with an outdoor gate this might cause a problem because of it getting rained on. I am curious. I am not so well versed in some things yet. I thought you had to have an electric current to create galvanic corrosion or will it occur with the introduction of water, salt, or some other combinations only? Sorry for my lack of knowledge.
STEF