Method for hot dip coating a flat steel product

US9279175B2 · kind B2 · utility

Assignee

• ThyssenKrupp Steel Europe AG · DE

Inventors

• Marc Blumenau · Hagen, DE
• Hans-Joachim Heiler · Moers, DE
• Fred Jindra · Lennestadt, DE
• Rudolf Schoenenberg · Daphne, US
• Hans-Joachim Krautschick · Solingen, DE

Key dates

• Filing date: Aug 18, 2011
• Grant date: Mar 8, 2016
• Expiry date: Jul 11, 2032

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23C2/40
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A method for hot dip coating a flat stainless steel product with more than 5 wt. % Cr with a protective metallic coating by: heating the flat steel product under an oxygen-free heating atmosphere to 100° C.-600° C. within 1-30 seconds; continuing heating to a holding temperature of 750° C.-950° C., by heating to 550° C.-800° C. under an inert or reducing atmosphere, holding within this temperature window for 1 to 15 seconds under an oxidizing atmosphere, and continuing heating under an inert or reducing atmosphere, until the holding temperature is reached; holding at the holding temperature for 10-120 seconds under a reducing atmosphere; and passing the flat steel product through a nozzle area under an inert or reducing atmosphere at 430°-780° C. and into a molten bath in which the flat steel product is coated with the metallic coating.