PASSIVATION STANDARD

[grayseal]

Is AMS QQP-35 the correct standard for the passivation of 304 ss that has free iron contamination?

grayseal

 

[TVP]

No, this standard is now obsolete. It has been replaced by SAE AMS2700. ASTM A 967 is also a passivation standard.

 

[SJones]

Is A380 not better?

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[israelkk]

I see nothing wrong with obsolete specs. I continue to to use QQ-P-35C unless there is a special request for different spec. Many times specs become obsolete because the newer has an additional type or class or the publisher authority was replaced. Such as when QQ-P-35 published by the federal transferred to SAE and was renamed SAE AMS QQ-P-35. Later on it was replaced by AMS 2700.

I do not have a copy of AMS 2700 and do not know if it is really a major change.

ASTM A380 is mainly for commercial use while AMS2700 and QQ-P-35 are for military and aerospace use. QQ-P-35 was adopted for commercial use by many users to.

 

[EdStainless]

You have to read A380 and A967 carefully.
A967 is the direct replacement for QQ-P-35 and covers passivation only, no other cleaning or treatments.
A380 is broader and covers pickling and other chemical treatment.
Both of them cover testing. The testing only addresses free iron on the surface. None of the tests determine the actual passivation of the material.

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