Method for controlling the coating weight for strip-phosphating

US6461450B1 · kind B1 · utility

Assignees

• Henkel Kommanditgesellschaft fur Aktien · DE
• THYSSEN KRUPP STAHL AG · DE

Inventors

• Joerg Riesop · Niederzier, DE
• Franz Ricke · Schwelm, DE
• Frank Panter · Dortmund, DE
• Dieter Geruhn · Werl, DE
• Hubertus Peters · Dortmund, DE
• Manfred Wessel · Welver, DE
• Andreas KLARE · Bad Iburg, DE

Key dates

• Filing date: Feb 16, 2001
• Grant date: Oct 8, 2002
• Expiry date: Feb 16, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23C22/13
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A process for controlling the layer weight during the phosphating of steel strip zinc-coated on one or both sides, using a phosphating solution which contains 1 to 6 g/l zinc ions and 10 to 30 g/l phosphate ions, characterized in that a Fe(II) ion content within the range of 3 to 100 mg/l is established in the phosphating solution. The higher the Fe(II) content, the lower is the layer weight. An alteration in the Fe(II) content of 3 to 20 mg/l results in an alteration in the layer weight of about 0.1 g/m2.