CONTINUOUS MANUFACTURE AND EQUIPMENT FOR METALLIC WELDED PIPE COMBINING HIGH-FREQUENCY PREHEATING WITH HIGH DENSITY ENERGY MELTING AND WELDING PROCESS

摘要

PURPOSE:To perform welding at high speed by preheating edges in opposition of a tubular body by high-frequency preheating equipment, pressing the edges by butt rolls and welding edge contact parts by high density energy welding equipment. CONSTITUTION:A metallic coil is formed into the tubular body 21 through forming rolls 6, 7 and 8 and an inductor 10 of the high-frequency preheating equipment 12 and as necessary, an impeder 9 are arranged on the pipe inside to carry out preheating. Welding is performed by a torch 14 of plasma welding, TIG welding, etc., with the welding equipment 15 to supply high density energy on the position separated from the soaking distance where the temperature difference in the direction of wall thickness of the edges can be equalized. As necessary, a bead is removed by a cutting device 18 and discharged by pull-out rolls 19. Since high density energy is charged after preheating, welding can be performed at remarkably high speed.