| 摘要 |
PURPOSE:To eliminate welding defects to be generated by deviation of a succeeding electrode from the centerline of welding by forming the sections of the preceding and succeeding electrodes with respect to the butt groove of low temp. service materials respectively into circular and rectangular shapes. CONSTITUTION:A backing strip 4 consisting of a copper plate 3 and a heat curable flux is forced upward by a hose 5 to the lower part of the groove 2 provided to materials 1 to be welded. Thereafter, the groove is welded from one side in a direction 10 by using a preceding electrode 6 of a circular section, a succeeding electrode 7 which has a rectangular section and of which the long side directions are disposed in the direction at a right angle to the welded joint line extending to the groove width, as well as a flux 8, whereby beads 9 are formed. On account of the above-described shape of the electrode 7, the quantity of weld heat input per unit area is decreased and therefore it is possible to reduce the spacing between the electrodes 6 and 7 sufficiently. It is therefore possible to melt the slag formed by the electrode 6 thoroughly, and to obtain the weld zones of beautiful bead appearance and high toughness at low temps. |
