Process for phosphatizing metals

US4419199A · kind A · utility

Assignee

• Occidental Chemical Corporation · US

Inventors

• Dieter Hauffe · Frankfurt am Main, DE
• Gerhard Muller · Grafing, DE
• Werner Rausch · Hopewell Junction, US
• Gudrun Volling · Frankfurt, DE

Key dates

• Filing date: Apr 30, 1982
• Grant date: Dec 6, 1983
• Expiry date: Apr 30, 2002

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23C22/12
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A process for the phosphatizing of metals, particularly iron, steel and zinc, in which the metal is contacted with acidic aqueous zinc phosphate solutions, containing an oxidizing agent, which contain PA1 from 0.4 to 1.5 g/liter of Zn, PA1 from 0 to 1.3 g/liter of Ni and PA1 from 10 to 26 g/liter of P.sub.2 O.sub.5, and in which the weight ratio of Zn to P.sub.2 O.sub.5 is adjusted to a value of (from 0.012 to 0.12):1 and of Ni to Zn to a value of (from 0 to 1.5):1, and the bath is supplemented with a concentrate, in which Zn, Ni and P.sub.2 O.sub.5 are present in a weight ratio of (from 0.18 to 0.33:(from 0 to 0.06):1, so as to obtain satisfactory phosphatizing results over a long period. Preferably, the zinc phosphatizing solutions, which, in addition, may also contain simple or complex fluorides and compounds that reduce the weight of the coat, are applied at a temperature within the range of from 30.degree. to 65.degree. C.