| 摘要 |
PURPOSE:To realize a good welding even in the case of there being an abutting step difference by performing an automatic TIG welding along the same weld line once again after flattening an abutting line part by performing TIG automatic welding of the abutting part of a thin pipe in the circumferential direction. CONSTITUTION:An automatic circumferential TIG welding is performed along an abutting line 3 by locating the electrode 7 of a welding torch 6 on the abutting line 3 of thin pipes 1, 2. At this time, a 1st welding bead 4 is formed by flattening the step difference H of the abutting line 3 part. A 2nd welding bead 5 is then formed by performing the automatic circumferential TIG welding again along the same weld line. In the case of the step difference H being big, a filler metal is used and in the case of the root gap being large, the initial welding current is made smaller than the next welding current. In the case of abutting the pipes 1, 2 in horizontal state, a downward welding is performed again. Thus, a good welding can be realized even in the case of there being an abutting step difference.
|
