METHOD OF AND MACHINE FOR ARC WELDING COMBINING GAS-SHIELD ARC WELDING WITH SUBMERGED ARC WELDING

摘要

Provided are a combination welding method and a combination arc welding machine thereof having excellent construction efficiency and preventing a deterioration of toughness of a HAZ by maintaining the current density of each of gas matal arc welding and submerged-arc welding within an appropriate range at the time of welding a steel plate by the combination of the gas matal arc welding using multielectrodes and the submerged-arc welding using multielectrodes. Specifically, in a combination welding method and a combination arc welding machine thereof for performing gas matal arc welding on a butted portion between steel plates and performing submerged-arc welding behind the gas matal arc welding, the gas matal arc welding is performed using two or more electrodes, a wire for welding having a wire diameter of 1.4 mm or more is used in the first electrode of the gas matal arc welding, and a current density of the first electrode is set to 320 A/mm 2 or more.