WELDING METHOD FOR SPIRAL STEEL PIPE

• Main Authors: HIROMOTO NOBUMI, WADA KOUICHI, OKA TAMOTSU
• Format: Patent
• Language: English
• Published: 12.02.1983
• Subjects: CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; SOLDERING OR UNSOLDERING; TRANSPORTING; WELDING; WORKING BY LASER BEAM

PURPOSE:To mitigate the flow of molten metal in an inclined attitude and to obtain sound bead shapes by deviating the joining part of a spiral forming part and a belt-like steel plate to the side of supplying the steel plate from the bottom part of the formed pipe and directing the arc in the advancing direction of the steel plate by means of a magnetic field. CONSTITUTION:A belt-like steel plate 7 is supplied from above a base plate 22 in the direction of an arrow (a), and a forming pipe part 14' is rotated horizontally in the direction of an arrow 6 on the plate 22. Then the plate 7 is bent to a forming roll 23 just before the plate is wound on the pipe 14' and the joining part 15 of the part 14' and the plate 7 is positioned with deviation to the supply side of the plate 7 from the center in a pipe bottom part 21. A torch 16 for welding the inside surface is installed at right angle to the inside circumference of the part 14' toward the part 15 at an angle theta of inclination around center of the pipe 14'. The arc is directed forcibly in the advance direction of the plate 7 by applying a magnetic field 25 from a transverse direction with an electromagnet 24 at the leading end of the torch 16.