ArcelorMittal S.A.
Method for producing a coated metal strip having an improved appearance

Abstract:

A process for manufacturing a coated metal strip having a metallic corrosion protection coating is provided. The process includes passing a metal strip through a molten metal bath comprising from 2 to 8 wt % aluminum, 0 to 5 wt % magnesium, up to 0.3 wt % additional elements, and a balance including zinc and inevitable impurities, to yield a molten metal coated metal strip, wiping the molten metal coated metal strip with a nozzle spraying a gas on either side of the molten metal coated metal strip and cooling the coating in a controlled manner until the coating has completely solidified, to obtain the coated metal strip. A temperature of the molten metal bath is from 350 to 700.degree. C., and the cooling is conducted at a rate less than 15.degree. C./s between a temperature on leaving a unit where the wiping occurs and a start of solidification of the coating, and then at a rate greater than or equal to 15.degree. C./s between a start and an end of solidification of the coating.