AMS 2700, AMS-QQ-P-35, ASTM A967, ASTM A380
Passivation is a critical step in maximizing the essential corrosion resistance of parts and components machined from stainless steels. The passivation process leaves a thin transparent oxide film that protects the stainless steel from corrosion.
TYPES
Type 1- Low temperature nitric acid with sodium dichromate.
Type 2 – Medium temperature nitric acid with sodium dichromate.
Type 3 – High temperature nitric acid with sodium dichromate.
Type 6 – Low temperature nitric acid.
Type 7 – Medium temperature nitric acid.
Type 8 – Medium temperature, high nitric acid concentration
CLASSES
CLASS 1 – fasteners, including nuts, bolts, washers, rivets and related hardware where a test frequency shall be specified by the customer.
CLASS 2 – Corrosion Resistance Testing
CLASS 3 – Testing in periodic basis
CLASS 4 – Visual Inspection
PASSIVATION-PROCESS CONTROL & TEST METHOD
VISUAL INSPECTION – AMS 2700, MIL-STD-753,
COPPER SULPHATE TEST – AMS 2700, MIL –STD-753, METHOD 102
WATER IMMERSION TEST – AMS 2700 MIL-STD-753 METHOD 100
HIGH HUMIDITY TEST – AMS 2700, MIL-STD-753 METHOD 101
POTASSIUM FERRICYANIDE TEST – AMS 2700, MIL-STD-753 METHOD 103
SALT SPRAY TEST – AMS 2700, MIL-STD-753 METHOD 104