
plating, anodizing, & finishing Q&As since 1989
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301 SS Passivated incorrectly
September 8, 2010
A subcontractor passivated 301 stainless steel parts using AMSQQP35 [canceled, affil. link] Type VIII instead of Type VI or VII. The parts showed rust in the bend radius, indicating ineffective cleaning and passivation, where I would expect it. 1. I've always have had an issue with the copper sulfate test, since typically, the copper sulfate solution is only applied to a small spot, likely a "flat" surface, and least likely to be an area with smeared iron. 2. Most importantly, I haven't a readily available published resource. Is there likely to be metallurgical attack of the 301 from Type VIII time-temperature-chemistry?
Douglas Hahnprocess engineer - Saint Charles, ILLINOIS
