Manufacturing method of mettalic pipes which are cladded inside

摘要

The process comprises: (a) inserting a pipe length (5) to form the subsequent internal plating with a close fit into a pipe blank (4) with a large wall thickness and a short length in comparison with its final dimensions, with the contacting surfaces machined beforehand to make them metallically bright; (b) in the resultant assembly, subjecting the pipe (5) simultaneously to internal pressure and axial compression; and (c) heating the resultant compound pipe to its hot-forming temperature, and then extruding to its final dimensions in a single stage.