Max Iron Content Of Nitric Acid Solution For Passivation
We use nitric acid at my employment for the passivation of stainless steel tanks, used in hard drive substrate manufacture. My question is to do with the maximum PPM level or %w/w allowed of iron in the nitric acid solution to clean the tanks.
Any help would be greatly appreciated.
- Limavady, U.K.
ASTM ASTM A380 [link is to the practice at TechStreet] -88, Standard Practice for Cleaning and descaling Stainless Steel Parts, Equipment and Systems,Annex A2, 'Recommendations and Precautions for Acid Cleaning of Stainless Steel'. paragraph A2.6 states "the concentration of iron should not exceed 2 weight %". I couldn't find a reference to iron contamination level in nitric acid passivation solutions in ASTM ASTM A380 [link is to the practice at TechStreet] , "Standard Specification for Chemical Passivation treatments for stainless Steel Parts".
I hope this helps.Thomas Kemp
- Erie, Pennsylvania