FORMING AND WELDING METHOD OF ELECTRIC WELDED STEEL PIPE

• Main Authors: TERASAWA TAKESHI, MIZUTANI WATARU
• Format: Patent
• Language: English
• Published: 08.11.1984
• 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 improve the quality of the weld zone of an electric welded steel pipe in forming and welding said pipe by inserting an insulator into the butt parts of the steel pipe. CONSTITUTION:A wedge-shaped insulator 6 is inserted into the butt parts 3 of a steel pipe and the tip of the insulator 6 is kept always pressed to a weld point 4. High-frequency electric current is conducted to the weld point 4 at the tip of the butt part by an electrode 5 for conducting high frequency in such a state, by which the point 4 is heated to melt. The molten part is joined by press contact with squeeze rolls 2, by which a pipe 1 is formed. The generation of an arc is thus suppressed before the point 4 and the electric current is conducted only near the weld point, by which the movement of the weld point is suppressed and stabilized and the generation of a defect is considerably improved.