SERVICES
ISO 9001:2000 Certified
Passivation Services
Passivation Services
Passivation Services offered are chemical treatments applied to stainless steel parts to provide resistance to oxidation, rusting and mild chemical attack. The Passivation process removes free iron (ferric material) from the surface of the parts that can be created during finishing operations such as milling, buffing, lapping, cutting, etc. These contaminants create potential sites for corrosion that result in premature deterioration of the component. The acids used for Passivation dissolve much of the alloyed iron on an atomic level right at the surface leaving a chromium and nickel-rich surface. It then creates the formation of a thin oxide film that protects the stainless steel from corrosion.
Advance Surface Technologies provides both Nitric and Citric Passivation treatments on Titanium and Stainless Steel alloys that adhere to QQ-P-35C, AMS-QQ-P-35A, AMS 2700C, ASTM A 967-05 and ASTM A 380-06 standards. Passivation alone will not remove heavy adherent oxide films created from heat treatment, welding, hot-forming and other high-temperature operations. Therefore AST uses different types of pickling acids designed to remove these films prior to the Passivation of the parts. Our extensive experience with Passivation allows us to choose and match the appropriate Passivation and pickling procedure for your needs and specific stainless steel grades.
ASTM A 967-05 Specifications · QQ-P-35C/AMS-QQ-P-35A Specifications · AMS 2700C Specifications
ASTM A 967-05 Specifications
| Nitric Acid Methods |
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| Citric Acid Methods |
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| Testing Methods | Practice A—Water Immersion Test (performed at AST) Practice B—High Humidity Test Practice C—Salt Spray Test Practice D—Copper Sulfate Test (performed at AST) Practice E—Potassium Ferricyanide–Nitric Acid Test Practice F—FreeIron Test (performed at AST) |
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| Passivation Types | Type I – Withdrawn Type II – 20-25 v% Nitric, 2-2.5 w% Sodium Dichromate, 120-130ºF, 20 minutes minimum Type III – Withdrawn Type IV – Withdrawn Type V – Withdrawn Type VI – 25-45 v% Nitric, 70-90ºF, 30 minutes minimum Type VII – 20-25 v% Nitric, 120-150ºF, 20 minutes minimum Type VIII – 45-55 v% Nitric, 120-130ºF, 30 minutes minimum |
| Testing Methods | 4.4.1.1 – Water Immersion Test (performed at AST) 4.4.1.2 – High Humidity Test 4.4.2.1 – Salt Spray Test 4.4.2.2 – Copper Sulfate Test (performed at AST) |
AMS 2700C Specifications
| Passivation Types1 |
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| Testing Methods | 3.2.1.1 Humidity 3.2.1.2 Water Immersion (performed at AST) 3.2.1.3.1 Copper Sulfate (performed at AST) 3.2.1.3.2 Salt Spray |
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