304 Discolloration in New tank
304 Discolloration in New tank
(OP)

Has anyone experienced this sort of corrosion in a new stainless product and what causes it?
Vessel was filled with tap water
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304 Discolloration in New tank
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RE: 304 Discolloration in New tank
RE: 304 Discolloration in New tank
The photo on the left is the door which is sealed by a rubber seal and the right photo is the frame of which the door seals against.
This style of corrosion is occurring all around the tank, even after the parts were acided and polished.
We manufacture 100s of tanks a year and this has never happened before
Is it possible the water it was filled with is contaminated?
RE: 304 Discolloration in New tank
It doesn't take much to get this staining on 304.
I suspect that it wasn't pickled well enough after welding, and then it should have been passivated (cleaned to remove residual iron in the surface) after polishing. That either traces of oxide were still embedded in the surface or that the Cr depeated material from just under the scale had not been removed.
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P.E. Metallurgy, consulting work welcomed
RE: 304 Discolloration in New tank
"If you don't have time to do the job right the first time, when are you going to find time to repair it?"