METHOD OF FORMING SEAMED METAL TUBE.

摘要

A method of forming a seamed metal tube (20c) having a metal coating (56) on at least an inside surface of the tube (20c) from a continuously moving, relatively flat metal strip (20a) is disclosed. The primary feature of the inventive process is the step, after forming and welding the seamed metal tube (20c), of locating the seam in a lower portion of the tube (20c) and reheating at least that lower portion of the tube (20c) to melt the coating (56). The coating (56) is thereby caused to flow downwardly over and to coat the inner surface of the seam. The result is a seamed tube (20c) with a more corrosion resistant seam region.