Patent ID: 8636854

Claim:
A method for coating a flat steel product including alloy constituents with a metallic coating, wherein the flat steel product is initially subjected to a heat treatment, in order then, in the heated state, to be hot-dip coated with the metallic coating in a melting bath including at least 85% zinc and/or aluminum, wherein the heat treatment comprises the following method steps: a) heating the flat steel product in a reducing atmosphere with an H 2 content of 2% to 8% to a temperature of >750° C. to 850° C., a heating-up speed during the heating of the flat steel product upstream of oxidation amounting to at least 2.4° C./s, whereby the heated flat steel product has a surface consisting predominately of pure iron such that an iron oxide layer can be formed on the same surface in the following step; b) converting said same surface from step a) into an iron oxide layer by a heat treatment of the flat steel product lasting 1 to 10 secs. at a temperature of >750° C. to 850° C. in a reaction chamber integrated into a continuous furnace, with an oxidizing atmosphere with an O 2 content of 0.01% to 1%; c) then annealing the flat steel product in a reducing atmosphere with an H 2 content of 2% to 8% by heating to a maximum of 900° C. over a period of time which is longer than the duration of the heat treatment carried out for the formation of the iron oxide layer such that the iron oxide layer formed previously is reduced at least on its surface to pure iron; and d) then cooling the flat steel product to melting bath temperature.