TWI629134B

A double-side submerged arc welding method for welding two end portions of vertically aligned Ni steel plates (1) from both sides while covering the end portions with flux (5), wherein, using a first wire (21) and a second wire (22) comprising a Ni-based alloy as electrodes, a first torch (31) from which the first wire (21) is extended toward a joint region where the two end portions come close to each other is moved along the joint region, and a second torch (32) from which the second wire (22) is extended toward the joint region from the opposite side to the first torch (31) is moved along the joint region (15) while the tip end of the second wire (22) is held behind the tip end of the first wire (21) by a specific distance of 10─60 mm.