Continuous treatment of steel sheet

US4389254A · kind A · utility

Assignee

• Centre De Recherches Metallurgiques-Centrum Voor Research in De Metallurgie · BE

Inventors

• Vittorino Tusset · Oupeye, BE
• Jules Hancart · Jupille, BE
• Philippe Paulus · Liège, BE

Key dates

• Filing date: Apr 28, 1981
• Grant date: Jun 21, 1983
• Expiry date: Apr 28, 2001

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23G1/088
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

Steel sheet is subjected to a thermal treatment as a result of which an oxide layer is formed. The sheet is pickled by contact with an organic acid solution (formic acid), containing at least 50 mg/l of iron, at a pH of 1.5 to 4 and at a temperature above a minimum value T.sub.m given by T.sub.m =20+(pH-1.5)32.