Pickling stains..

[MrMetals]

I have some Alloy C22 that has some blackish stains around the length of a tube. The pipe looks smudged and foggy and the dark stains are not in any particular pattern down the length of the pipe. If they are pickling stains, this would not affect the corrosion resistance of the pipe, correct? If they are not pickling stains, I do not know what it could be.

 

[EdStainless]

If you rub them do they wipe off? Then it is picking stain.
I would probably not hurt corrosion resistance.
But it is poor workmanship. No excuse on this alloy.
If it is actually residual oxide on the surface (under pickled) then you would have serious corrosion issues.

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Plymouth Tube

 

[MrMetals]

Yea that's the problem the material is already in transit. I have heard that a dilute muriatic acid solution would wipe the material clean from grime and oils. I agree that this is poor workmanship if incomplete pickling has occurred.