| 摘要 |
PURPOSE:To perform tack welding to form a continuous and stable bead by lowering an arc voltage of a succeeding electrode when a plural weld electrode is approached at the edge of base metal to carry out gas shield arc welding. CONSTITUTION:In gas shield arc welding to carry out tack welding of base metal using a plural consumable electrode, molten metal 4 from an arc 3 of a proceeding electrode 1 is intercepted by an arc 5 of a succeeding electrode 2 to form a weld bead. When the weld electrode approaches at the edge of base metal, the voltage of the succeeding electrode 2 is lowered and arc length of an arc 5 is shortened to carry out tack welding. Therefore, the decrease of arc power by magnetic blow are prevented to show the sufficient effects of interception a molten metal 4 and a continuous weld bead is formed to prevent the occurrence of weld defects in this welding. |
