Process for coating the surface of elongated materials

摘要

The invention is directed to a process and apparatus for coating the surface of elongated materials, in particular steel strips, with a metallic coating. The material is guided in one direction through a tank holding the molten coating material. The tank has a through-duct surrounded by an electric field below the surface of the molten bath. An electromagnetic force is generated in the region where the through-duct opens into the melt, which electromagnetic force is equal to or greater than the metallostatic pressure, directed oppositely thereto vectorially and quantitatively proportional to the product of the cross-sectional area of the inlet opening and the metallostatic pressure, and in which the dwell of the strip in the melt can be controlled independently of the rate of feed of the strip. The molten is constantly moved against the surface of the elongated material while the elongated material passes through it; and the molten material is circulated in a closed system, without contact to oxygen in the atmosphere.