Passi Test for Pickling and Passivation of Stainless Steel

[Material98]

For one of our project, because of environmental constraints, We have got COMPANY approval to use Sulfuric Acid as chemical for Pickling and Passivation instead of Nitric Acid. COMPANY is asking to do Ferroxyl testing and Passi Testing. Ferroxyl testing requirements are specified in A380. However, no detail found about Passi Testing. It is requested if someone can please share any detail about Passi Testing. Much Appreciate if ASTM number is shared. Thanks

 

[metengr]

https://www.koslow.com/3036-stainless-steel-passivation.html

 

[EdStainless]

I hope that your material had been very well pickled before you used sulfuric on it.
We have pickled in hot sulfuric+HF, but we had to follow with a dip in nitric in order to get consistently good results.
There are tests other than the ferroxyl, look in A967.
I have had poor luck with the Koslow and similar devices.
They seam too sensitive to other variations (surface finish and such).
What we do for a first test (unofficial) is cover an area with moisture trapping material (the stuff the disposable diapers are made from) and wet it down with DI water. After being wet for 24 hours we look for signs of rust staining.

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P.E. Metallurgy, Plymouth Tube