What supersedes QQ P 35?
QQ-P-35 has been cancelled and superseded by ASTM A967 or AMS-QQ-P-35. AMS-QQ-P-35 has been cancelled and superseded by AMS 2700.
What is passivate per ASTM A967?
The ASTM A967 passivation standard applies to the cleaning, passivation and testing of stainless steel parts. Per passivation standard, ASTM A967 requires the parts to be immediately neutralized post immersion followed by a chemical treatment to treat the surface of the part.
What steels can be passivated?
Metal Passivation: Preventing Iron & Steel from Getting Active
- Stainless steel has a passivation layer that protects it from corrosion.
- Passivation was discovered during explorations of electrochemical reactions.
- Stainless steel alloys include chromium and other elements to create a passive layer.
How do you passivate steel?
The most commonly used chemical method to passivate a stainless steel surface is to apply nitric acid. Nitric is a strong mineral acid and will quickly dissolve all iron compounds and other trace metals on the surface. It is also a strong oxidizer and will simultaneously activate the chromium oxide layer.
Do you have to passivate after pickling?
After the process is completed, it is imperative to ensure that all residual acids are removed and neutralized to prevent pitting and corrosion. For optimum corrosion resistance, proceed with passivation process.
How is passivation done?
Passivation is a widely-used metal finishing process to prevent corrosion. In stainless steel, the passivation process uses nitric acid or citric acid to remove free iron from the surface. The chemical treatment leads to a protective oxide layer that is less likely to chemically react with air and cause corrosion.
What is the passivation temperature for QQ-p-35c?
QQ-P-35C/AMS-QQ-P-35A SPECIFICATIONS Passivation Types Type I – Withdrawn Type II – 20-25 v% Nitric, 2-2.5 w% Sodium Dichromate, 120-130ºF, 20 minutes minimum Type III – Withdrawn Type IV – Withdrawn Type V – Withdrawn Type VI – 25-45 v% Nitric, 70-90ºF, 30 minutes minimum Type VII – 20-25 v% Nitric, 120-150ºF, 20 minutes minimum
Does QQQ-P-35 cover nitric acid passivation?
QQ-P-35 does not cover citric acid passivation services. Four active nitric acid passivation services are covered as follows (four inactive methods have been withdrawn): Four testing methods to validate passivation services are provided as follows:
What is the QQ-P-35 specification?
This specification covers the different types of passivation treatments as well as recommendations, guidance and precautions for cleaning and descaling corrosion-resistant parts, components, equipment and systems. Many of the QQ series of Federal Specifications are withdrawn now, and QQ-P-35 is no exception.
What is the passivation specification?
This specification covers the different types of passivation treatments as well as recommendations, guidance and precautions for cleaning and descaling corrosion-resistant parts, components, equipment and systems. 1.2 Purpose.