To provide an automatic gas tungsten arc welding method capable of obtaining excellent penetration of the root pass welding while avoiding hydrogen embrittlement.
The method includes: a step of preparing beveled workpieces 12 with beveled joint areas having minimal land thickness at the root extremities; a step of placing the prepared workpiece joint sections together with an open gap between their adjacent root extremities, the gap having a minimum dimension that avoids harmful compression stress between the workpieces due to weld shrinkage and a maximum dimension that avoids filler wire penetration of the gap; a step of fusion-welding the open root area of the adjacent workpieces 12 with a root pass weld using an automatic GTAW welder 20 supplied with filler wire and shield gas including 1 to 10% hydrogen gas and the balance inert gas; and a step of then promptly overlaying the root pass weld with at least one additional filler weld pass using the automatic GTAW welder 20 supplied with filler wire and hydrogen-free shield gas.
PORTER MICHAEL R
| JPH07100652A | 1995-04-18 | |||
| JPS5927784A | 1984-02-14 |
Satoshi Kono
Makoto Nakamura
Yoshihiro Fukuhara
Toshio Shirane
Sadao Muramatsu