Method for enhancing corrosion resistance of a metallic coating on a steel strip or plate

US9115428B2 · kind B2 · utility

Assignee

• thyssenkrupp Rasselstein GmbH · DE

Inventors

• Winfried Hoehn · Neuwied, DE
• Helmut Oberhoffer · Annweiler am Trifels, DE
• Benjamin LIEBSCHER · Welschneudorf, DE
• Reiner Sauer · Neuwied, DE

Key dates

• Filing date: Jan 2, 2012
• Grant date: Aug 25, 2015
• Expiry date: Jan 2, 2032

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/12937
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

The invention relates to a method for enhancing a metallic coating on a steel strip or steel plate, the coating being melted by heating to a temperature above the melting temperature of the material of the coating, the heating taking place by irradiation of the surface of the coating with electromagnetic radiation having a high power density over a limited irradiation time of not more than 10 μs, and the mandated irradiation time and the energy density introduced into the coating by the electromagnetic radiation being selected such that the coating melts completely over its entire thickness down to the boundary layer with the steel strip, thereby forming a thin alloy layer at the boundary layer between the coating and the steel strip. The invention further relates to a steel strip or steel plate having a metallic coating, more particularly a coating of tin, zinc or nickel, in which, at the boundary layer between the steel and the coating, an alloy layer which is thin—compared with the thickness of the coating—and at the same time is dense, and is composed of iron atoms and atoms of the coating material, is formed, the thickness of the alloy layer corresponding to an alloy-layer add…