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Procedure for Testing Success of SS Passivation

Sir,

I am a quality assurance engineer working for a manufacturer of eco-friendly solar products like solar water heating systems, solar lanterns, etc. We are planning to set up a passivation unit in our campus for passivating stainless steel tanks- both inside and outside. We have conducted some tests in our lab. I want to know the exact method of testing for passivation in the laboratory and how to ensure that we get optimum results. We are using nitric acid for passivation. In case you have any laboratory manual for passivation please send us a copy.

Thanking you,

It is unlikely that you will receive detailed procedures unless buying a commercial passivation solution, e.g., Citrisurf from Stellar Solutions [a finishing.com supporting advertiser], or a passivation tester as mentioned in letter 26084.

ASTM A967 Standard Specification for Chemical Passivation Treatments for Stainless Steel Parts (available from www.astm.org) covers both passivation and testing. For mechanical and chemical pretreatments, more details are given inASTM A380 Standard Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and Systems. For a very basic passivation procedure, AMSQQP35 [canceled]C PASSIVATION TREATMENTS FOR CORROSION-RESISTANT STEEL is a free download from the ASSIST site: http://assist1.daps.dla.mil/quicksearch/. For cleaning and other pretreatments, this procedure refers to MIL-S-5002 (also skimpy) and ASTM A380 . The latter is more detailed and especially useful for welded materials.

Passivation testing procedures are also given in MIL-STD-753 [on DLA / cancelled] [ed. note: replaced by AMSSTD753 ] CORROSION-RESISTANT STEEL PARTS: SAMPLING, INSPECTION AND TESTING FOR SURFACE PASSIVATION. The MIL specifications are available from ASSIST.

dear Sir,

Can you please provide the Passivation procedure for SS pipes with nitric acid.

How much concentration nitric acid we can use for passivation?

Hi, Srinivasa. I believe that both the procedure and the chemical concentrations are in the industry standards which Ken identified for us. If you have questions after consulting them, please follow up. Thanks.

Regards,

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