METHOD FOR AUTOMATIC OVERHEAD SUBMERGED ARC WELDING AND APPARATUS FOR CARRYING OUT THE METHOD

PCT No. PCT/SU88/00263 Sec. 371 Date Feb. 6, 1990 Sec. 102(e) Date Feb. 6, 1990 PCT Filed Dec. 14, 1988 PCT Pub. No. WO89/11945 PCT Pub. Date Dec. 14, 1989.The invention relates to technology and equipment for arc welding. A method of overhead submerged arc welding consists in that flux at the welding site is pressure-fed to the joint being welded from below at different pressures along the joint being welded, a consumable electrode (3) is fed through the flux (3) from below and an arc is struck. A weldpool is formed thereat with a layer of liquid slag. The joint is welded by feeding the flux (A) on the section (A) before the arc relative to the weld being formed under a constant pressure, needed to provide conditions for pressuring the weldpool, and on the section of the arc burning and the weldpool location pressure is exercised through a layer of flux and a layer of liquid slag, the bulk of the flux being pressure-fed to the zone of the weldpool formation and the pressure gradually built up in a manner that its maximum value is distributed along the boundary of the section of the beginning of the weld solidification and maintained constant all along the boundary of solidification. Then solidification is effected and the weld is formed. There is also proposed an apparatus to implement the method. The invention may be used for welding longitudinal and circumferential rotatable joints.