Stainless Steel Passivation improves corrosive resistance and the durability of the material, especially in atmospheric corrosion. Despite its name, in case of exposer of stainless steel to salty atmosphere may cause formation of corrosion- though slowly than steel.
Passivation Process
Passivation for stainless steel is a chemical procedure that removes the iron from the surface of the stainless steel and is performed in the air. At the end of the passivation process a natural, transparent oxide is created from the oxygen in the air. This oxide provides the stainless steel with the necessary corrosion resistance.
Metal Finishing & Plastic LTD is certified by IAI to perform stainless steel passivation according to PS.
Standard QQ-P-35
Table according to Type
Solutions based on nitric acid compositions and at different temperatures
Type
|
Solution Composition
|
Temperature
|
Type 2
|
nitric acid based solution
|
Moderate
|
Type 4
|
nitric acid based solution
|
Low
|
Type 7
|
nitric acid based solution
|
Moderate
|
Type 8
|
nitric acid based solution
|
?
|
Standard ASTM A 967
Recent standard which uses other nitrogenous solutions for nitric acid based solutions
Table according to Nitric
Nitric
|
Solution Type
|
1
|
Solution based on nitric acid and supplements
|
2
|
Solution based on nitric acid at room temperature
|
3
|
Solution based on hot nitric acid
|
4
|
Solution based on hot nitric acid
|
Citric Acid Based Solutions
Table according to Citric
Citric
|
Solution Composition
|
Temperature
|
Time
|
1
|
Citric Acid Based Solution
|
High
|
Short
|
2
|
Citric Acid Based Solution
|
Moderate
|
Medium
|
3
|
Citric Acid Based Solution
|
Low
|
Long
|
4
|
Citric Acid Based Solution or any other mixture that enables compliance with the Standard
|
|
|
5
|
Citric Acid Based Solution or any other mixture that enables compliance with the Standard according to defined acidity
|
|
|
IAI standard PS 23.1900
Classification according to Type
Type
|
Solution Composition
|
2
|
nitric acid based solution and supplements
|
4
|
nitric acid based solution
|
8
|
nitric acid based solution
|
Classification according to Group
Group
|
Stainless Steel Composition
|
1
|
Stainless Steel that contains more than 17% chrome (except 440C stainless steel)
|
2
|
Stainless Steel that contains less than 17% chrome
|
Aerospace Standard AMS 2700
Classification according to Type
Type
|
Solution Composition
|
Temperature
|
Type 1
|
nitric acid based solution
|
Low
|
Type 2
|
nitric acid based solution
|
Moderate
|
Type 3
|
nitric acid based solution
|
high
|
Type 4
|
highly concentrated nitric acid solutions for processed steels
|
|
Type 5
|
Electric based passivation for steels that contain high carbon martensitic
|
|
Type 6
|
nitric acid based solution
|
Low
|
Type 7
|
nitric acid based solution
|
Moderate
|
Type 8
|
highly concentrated nitric acid solutions
|
|
Classification according to Method
Method
|
Solution Basis
|
1
|
nitric acid based solution
|
2
|
nitric acid based solution
|
Classification according to Class
Class
|
Testing frequency
|
1
|
Testing frequency according to demand
|
2
|
Testing of item per dose
|
3
|
Testing frequency according to period
|
Passivation for Stainless Steel