Passivation of Stainless Steel

Passivation of Stainless Steel Prepares the Surface and Protects Against Contamination
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 imbedded 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.

Features • 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.		Specifications • 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 take care in passivating austenitic or low chromium grades of stainless steel. Request a passivation quote. 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.