Patent ID: 8652275

Claim:
A process for melt coating a strip of steel having one or more alloy constituents including at least one of Mn, Al, Si and Cr, in a molten bath of in total at least 85% zinc, aluminum, or both in a cycle involving the following process steps: a) heating the strip in a reductive atmosphere having an H 2 content of 2% to 8% to a temperature of from 650° C. to 750° C., wherein the heated strip has a diffusion suppressed surface at which the alloy constituents have not yet diffused to a surface of the strip or have done so merely in small amounts such that an iron oxide layer can be formed on the same diffusion suppressed surface in the following step; b) converting the diffusion suppressed surface, consisting predominantly of pure iron, into an iron oxide layer by heat treatment, for a treatment time lasting from 1 to 10 sec, of the strip at a temperature of from 650° C. to 750° C. in a reaction chamber which is integrated in a continuous furnace and has an oxidizing atmosphere having an O 2 content of from 0.01% to 1%; and c) annealing the strip in a reductive atmosphere having an H 2 content of from 2% to 8% by further heating the strip up to at most 900° C. and then cooling the strip down to a temperature of the molten bath, the iron oxide layer being reduced to pure iron at least at its surface.