COMBINATION WELDING METHOD OF SIMULTANEOUSLY PERFORMING RESISTANCE WELDING, TUNGSTEN ARC WELDING AND SUBMERGED ARC WELDING

摘要

There is provided a combination welding method performed by leading with a tungsten arc welding method and following with a submerged arc welding method by keeping a predetermined separation distance from the tungsten arc weld zone. According to the combination welding method of the present invention, the occurrence of bending of a steel pipe is reduced and a welding time is shortened since the inside welding and the outside welding are simultaneously performed by keeping the predetermined separation distance. In addition, since the outside welding is performed before a fusion area temperature is below an A1 transformation point after the inside welding, the bending of the steel pipe is properly controlled after the welding and therefore straightening time in a post-process is shortened.