Galvannealed metal sheet and method for manufacture of such metal sheet

US6887590B2 · kind B2 · utility

Assignee

• THYSSEN KRUPP STAHL AG · DE

Inventors

• Sabine Zeizinger · Mülheim, DE
• Horst Berndsen · Duisburg, DE
• Frank Friedel · Leuna, DE
• Manfred Meurer · Rheinberg, DE
• Michael Westholt · Castrop-Rauxel, DE

Key dates

• Filing date: May 15, 2001
• Grant date: May 3, 2005
• Expiry date: Nov 22, 2021

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/12799
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The present invention relates to a method for the manufacture of galvannealed metal sheet, wherein a hot strip is produced from an IF steel containing 0.01 to 0.1 wt. % silicon, wherein the hot strip is coiled at a coiler temperature no lower than 700° C. and no higher than 750° C., wherein a cold strip is rolled from the coiled hot strip, wherein the cold strip is recrystallization-annealed in an annealing furnace in an annealing gas atmosphere, wherein the cold strip thus annealed is provided with a zinc coating in a zinc bath, and wherein the coated cold strip is post-annealed at a galvannealing temperature no lower than 500° C. and no higher than 540° C. The invention also relates to a galvannealed metal sheet which possesses improved adhesion of the coating layer to the base material and proposes a method which is suited for the manufacture of metal sheet having such properties.