Abstract: A one-side submerged arc welding method includes setting: a welding speed transition section, in which welding is performed such that a welding speed is lowered from a welding speed of main welding to a welding speed being 80% or less of the welding speed of main welding; and a low welding speed section, in which welding is performed at a welding speed being 80% or less of the welding speed of main welding. A length of the welding speed transition section is set to be more than 200 mm and 1,000 mm or less. The low welding speed section is set as a section from a position of 100 mm or more and less than 1,000 mm in front of the end part of the steel plates to the end part.

Abstract: A one-side submerged arc welding method, includes joining two steel plates butted against each other by submerged arc welding from one side using a plurality of electrodes. During the submerged arc welding, at least one of electrode distances between adjacent electrodes in an end part region of the steel plates is reduced to be smaller than the at least one of electrode distances in a region in front of the end part region. Variation in heat input into the electrode moved so as to reduce the at least one of electrode distances in a transitional region in which the at least one of electrode distances is reduced is within 20% relative to the heat input at a starting point of the transitional region.

Abstract: A one-side submerged arc welding method, includes joining two steel plates butted against each other by submerged arc welding from one side using a plurality of electrode. During the submerged arc welding, at least one of electrode distances between adjacent electrodes in an end part region of the steel plates is reduced to be smaller than the at least one of electrode distances in a region in front of the end part region. In reducing the at least one of electrode distances, an increasing section of change rate from when a change of the at least one of electrode distances starts to when the change rate of the at least one of electrode distances reaches its maximum has a time of 2 seconds or more.

Abstract: A one-side submerged arc welding method includes joining two steel plates butted to each other by submerged arc welding from one side using a plurality of electrodes. During the submerged arc welding, at least one of the electrode distances between adjacent electrodes in a terminal end region of the steel plates is changed.