GB1315420A - Method for the electric-arc welding of tubular workpieces - Google Patents

Abstract

1315420 Welding by fusion J I RAICHUK Z O KNYAZHINSKY S L MANDELBERG V K LEBEDEV and V N VOLKOV 4 June 1971 18940/71 Heading B3R [Also in Division H5] In helical seam arc welding of a pipe, magnetic influence of the arc and the molten pool is achieved by an auxiliary current flowing in the workpiece along the generating lines thereof, the auxiliary current being additional to that supplied to the arc. The auxiliary current source may be D.C., A.C., pulsating or a combination thereof. As shown, a welding current source 10 is connected between a flux-submerged internal welding electrode 5 and, via a contact 7, the workpiece; and an auxiliary current source 6 is connected to the workpiece via contact 7 and a further contact 8. The polarity connections of the sources are such that the current from the source 6 deflects the arc generally in the direction of welding and forces act on the molten pool in a direction radially inwardly of the workpiece to prevent molten metal running out of the pool. To avoid current by-passing, the workpiece is preferably insulated from the welding machine on at least one side of the normal plane passing through the workpiece axis and containing the arc, as by spacers 11. If desired, the auxiliary current may also be utilized in respect of the external seam weld effected by a flux submerged electrode 13 at a position 1¢ turns distance from the internal welding arc.