| 摘要 |
In a method for butt welding a steel plate with submerged arc welding by welding a top side of the steel plate after welding a bottom side thereof, an angle ¸1 between a top side borderline and a line perpendicular to a first parallel line is 15° or more, the top side borderline connecting a junction and a first intersection point, the junction being an intersection between a melting borderline of bottom side weld metal and a melting borderline of top side weld metal, the first intersection point being an intersection between a first parallel line and the melting borderline of the top side weld metal, the first parallel line traversing a position 5 mm from the junction in a direction of an upper surface of the steel plate and being parallel to the upper surface. An angle ¸2 between a bottom side borderline and a line perpendicular to a second parallel line is 15° or more, the bottom side borderline connecting the junction and a second intersection point, the second intersection point being an intersection between a second parallel line and the melting borderline of the bottom side weld metal, the second parallel line traversing a position 5 mm from the junction in a direction of a lower surface of the steel plate and being parallel to the lower surface. A total heat input Q (kJ/cm) of a bottom side welding heat input and a top side welding heat input of the steel plate and a wall thickness t (mm) of the steel plate satisfy the relationship Q ‰¤ 1.3 × t 1.37 . A high-toughness welded heat affected zone is thus stably obtained. |
