Passivation - Maximum Stainless Steel Protection

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Passivation - Improving Corrosion Resistance

Passivation improves the corrosion resistance properties of components made of precipitation-hardened, austenitic, ferritic and martensitic steels. Passivation treatments improve the surface condition of stainless steel by dissolving iron that has been im-bedded in the surface during forming or machining. If allowed to remain, the iron can corrode and give the appearance of rust spots on the stainless steel.

Passivation, which consists of immersing stainless steel components in a solution of nitric or citric acid without oxidizing salts, will dissolve the imbedded iron and restore the original corrosion-resistant surface by forming a thin, transparent oxide film.

Passivation - Corrosion Resistance

Features

Specifications

• Maximum stainless steel corrosion protection without plating.
• Superior clean surface.
• Eliminates iron contamination reactions with
other materials.
• No rust discoloration.
• Surface prepared for priming and painting.

               AMS-QQ-P-35 (Replaced QQ-P-35)
               AMS 2700
               ASTM A-380
               ASTM A-967
               ASTM B-254
               ASTM F-86 (Titanium Components)
               MIL-S-5002

Testing

Water Immersion

Verifies the passivation process on all grades of stainless steel, with exception of 440C. After testing, speciments shall show no signs of rust or corrosion.

Copper Sulfate

Verifies the passivation of austenitic stainless steel in the 200 and 300 series conducted in accordance with MIL-STD-753 Method 102. The specimens shall show no signs of copper deposit.

Salt Spray

Performed in accordance with ASTM B117 for 2 hours, when specified by engineering drawings. After testing, specimens shall show no signs of rust, stain or corrosion.

Applications

The Electrolizing Corporation of Ohio passivation process meets ASTM A-967-01 and AMS-QQ-P-35, Types 2, 6, 7 and 8.
We process large vessels that call for ID passivating, components that require special setups, and components from micro to 3’ x 4’ x 6’ in size. We take care in passivating austenitic or low chromium grades of stainless steel. We do not recommend passivating stainless steel that has a carbonized/nitrided surface, because nitric acid will dissolve the surface and reduce the size of the component. It is important that you identify the type of stainless steel to be passivated.