PURPOSE: To improve resistance welded tube quality by blowing a flame against the vicinity of a welding butt point from the welding heating region at the time of performing electric resistance welding of a resistance welded tube seam.
CONSTITUTION: At the time of performing welding of the resistance welded tube seam, welding is performed while blowing the flame 3 against the whole or a part of the vicinity of the welding butt point 8 from the welding heating region 7. When CO gas and combustion gas such as H2 are blown against the vicinity of the welding butt point 8 from a gas burner 4, oxygen concentration is low and reducing gas exists in the inside of the flame 3, hence the generation of an oxide is reduced and the oxide is reduced. By this method, weld defects of an oxide system generated at the time of manufacturing the resistance welded tube are suppressed. Accordingly, resistance welded tube quality is improved.
SUZUKI NORIAKI
TOYODA TETSUJI
TSUNODA TADASHI
KONNO NAOKI
KOYUMIBA MOTOFUMI
