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Ammonium Phosphate forming on stainless steel

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White granular film was discovered on "Stainless Steel" material. Apparently the stainless steel is 304 grade. We are trying to get a contaminated part and have it analyzed for verification. A swap sample of contaminant was taken for analysis. Result indicated that the substance is Ammonium Phosphate Crystals. How could Ammonium Phosphate crystals form on Stainless Steel?

Are there any passivation processes, welding, or other processes that can cause this problem?

I appreciate any help.

Massoud Rezaei
Automated Material Handing - Salt Lake City, Utah, USA

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I'm sorry but I don't quite understand, Mr. Rezaei. This fabricated material was in some unknown service environment after you built a machine from it? Or the incoming stainless steel from the mill doesn't look right? Certainly if it was used in an ammonium phosphate manufacturing or packaging environment this would happen.

Ted Mooney, P.E.
finishing.com
Brick, New Jersey

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