| 摘要 |
PURPOSE:To obtain a complete joint even if a fitting gap before welding is large, by providing lap fillet welding of a thin Al pipe by TIG welding method with one pass for fusing the circumference of a socket-side base material corner part before fusing the corner part. CONSTITUTION:The thin Al pipe consisting of the socket-side base material 7 and an opposite base material 8 is as shown in a figure. A welding torch 9 is set nearly at right angles to the pipe center axis and while an arc is directed to a position at about 1mm. distance from the corner part of the base material 7, the torch is moved in a circumferential direction. In the 1st pass, a welding current is held at slightly state less except at a starting position and only the circumference of the corner part of the base material 7 is fused. Consequently, the corner part circumference of the base material 7 has a rounded shape 10 because of surface tension and the fitting gap with the base material 8 is less than before. consequently, the base materials become easy to fuse in one body, so the torch 9 is further moved until one turn to fuse the corner part circumference again to fuse the base materials in one body completely, thus finishing a lap fillet joint. |
