Dezincification of brass?

[daspferd88]

I have a brass component showing signs of corrosion, namely dark reddish/brown spots splattered on it. It's my understanding that this could be signs of dezincification, caused by exposure to water, acid, or salt. Now, I've also seen a greenish/turquoise corrosion on brass as well which I've read is copper sulfates/carbonates as a result of copper oxidation. My question: is the green corrosion simply a later stage of dezincification, i.e. after all the zinc has been selectively leached away, the copper is the next element to react? Or is this type of corrosion simply the result of exposure to different types of chemicals that cause the copper to react and not the zinc?

 

[EdStainless]

Depending on the alloy and environment you may get multiple stages, or it may just dealloy.
More details would help.

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P.E. Metallurgy, Plymouth Tube

 

[berkshire]

Once the zinc has been leached away the material will crumble; If you have brass components in a system, it is good to install sacrificial zinc anodes to help defray this kind of corrosion. Are you in a salt water environment?
B.E.

You are judged not by what you know, but by what you can do.

 

[mrfailure]

Green means you are seeing oxidation of copper. This can well be an effect of loss of zinc in the brass.