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Concentration of acid required for passivation

WHAT IS THE CORRECT CONCENTRATION OF NITRIC OR citric acid FOR PASSIVATION OF 304 ss.

THANK YOU

FRANK CALABRESE
DIETRAY SUPPLEMENTS - W.CALDWELL, New Jersey
2004

Well, that would depend on what specification that you are going to do the work to.

James Watts
- Navarre, Florida
2004

Nitric acid in most any concentration will work - depends on time and temp. Most use 25-50%. citric acid ? Question is - does citric really work? I've seen evidence both ways.

Jeffrey Holmes, CEF
Spartanburg, South Carolina
2004

2004

Frank,

Following ASTM A967, the concentration of citric acid should be 4 to 10 pecent by weight. Let us know if we can be of assistance.

Lee Kremer
Stellar Solutions, Inc.

McHenry, Illinois

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