PRODUCTION OF POWDER AND GRANULAR MATERIAL FILLED PIPE

摘要

PURPOSE:To provide a manufacture for production of the powder and granular material filled pipe which is free from cracking in a pipe sheath by obtaining a defectless joined weld zone. CONSTITUTION:This manufacturing method for the powder and granular material filled pipe consists in supplying the powder and granular material into a tubular body in the process of molding a metallic strip to the tubular body and joining both edge surfaces of the tubular body by high-frequency welding and diametrally reducing the welded pipe filled with the powder and granular material. While the edge surfaces near the upstream side at a V converging point are irradiated with a laser beam, these edge surfaces are high-frequency welded at the heat input quantity over the permissible lower limit heat input quantity PELN which is the max. heat input quantity to generate cold crack and below the permissible upper limit heat input quantity PEUN which is the min. heat input quantity to generate spatters of grain sizes above the inside diameter of the final finished pipe.