Process for coating elongated materials with multiple layers

摘要

The invention is directed to a process for coating elongated metallic material, particularly strip or wire, with multiple layers by applying different layers of metallic coating materials while the material to be coated travels continuously through an installation having a plurality of dip baths of molten coating materials which are arranged one after the other. In order to produce new corrosion-resistant coatings with improved properties and improved surfaces, the invention provides that the elongated metallic material is guided in a straight line through the installation so as to be regulated in temperature via the adjustable bath temperatures of the different molten coating materials. The device used for this purpose is characterized by a plurality of treatment tanks (4a, 4b) arranged in series and having through-ducts (12) for the elongated metallic material (B) below the surface (h) of the dip bath, the through-ducts (12) being closed by magnetohydrodynamic seals (13).