METHOD FOR PRODUCING CLAD TUBULAR PRODUCT

摘要

A powder-metallurgy method for producing tubular product having at least one surface and preferably an internal surface thereof clad with an alloy different from the preferably more resistant to destructive media than the material from which the remainder of the tubing is constructed. An assembly is constructed of a metal tubing having an internal surface to be clad and a tubular insert mounted generally axially within the tubing in spacedapart relation to the internal surface thereof, which provides a generally annular cavity between the internal surface of the tubing and the tubular insert. This cavity is filled with metal particles of a composition to be clad on the tubing internal surface. The cavity is sealed and the assembly is heated to an elevated temperature at which it is forged to compact the metal particles introduced to the cavity to substantially full density and metallurgically bond the particles to the internal surface of the tubing to provide a desired destructive-media resistant cladding. The forging operation includes passing the assembly along a feed path having an axis through a forging box having a plurality of hammers evenly spaced around the assembly. The hammers extend and retract radially with respect to the feed-path axis to impart a radial forging action to the assembly as the assembly passes through the forging box.