| 摘要 |
<p>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 5 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 io temperature is below an Al 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. [Figure 3] ---- m* Outside welding Uneolier Leveler Forming -faeding raw material coil - leveling the raw material coil - forming a pipe form using rllers Welder weldsng using ERW method the combinat on process of SAW+GTAW Heat retment St.raightening Non-festructive test</p> |
