| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a multi-electrode submerged arc welding method suitable for the pipe-making welding of a large-diameter steel tube such as a UOE steel tube and a spiral steel tube having the thickness of≥25 mm. <P>SOLUTION: When executing the single-layer welding of inner and outer surfaces by the two-or-more electrode submerged arc welding of a steel material of the thickness of≥25 mm, the current density of the first electrode is set to≥220 A/mm<SP>2</SP>for both the inner surface welding and the outer surface welding, the wire center-to-center distance between the first and second electrodes on the surface position of the steel material is set to≥25 mm, and the current ratio of the first electrode to the second electrode is set to≤0.8. Further, the influence of the groove shape, the welding speed and the current on the penetration depth in each of the inner surface welding and the outer surface welding is represented by the value obtained by the parameter formula (where L<SB>IW</SB>denotes the penetration depth of the inner surface weld metal, and L<SB>OW</SB>denotes the penetration depth of the outer surface weld metal). The groove dimension and the welding condition are selected so as to satisfy the parameter formula consisting of these values and the thickness. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
