摘要 |
The invention provides a method and composition for coating a ferrous metal surface with a zirconium/vanadium conversion coating which is substantially free of an organic film forming composition and tannins. The method is a low temperature method which contemplates an aqueous conversion coating composition which is low in phosphates and which comprises zirconium, vanadium, fluoride, as well as phosphate ions in a ratio and a concentration effective for providing a conversion-coated ferrous metal surface.
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