| 摘要 |
PROBLEM TO BE SOLVED: To provide a groove structure in the laser-arc hybrid butt welding, capable of easily securing an appropriate amount of a root gap in the field to thereby perform good welding.SOLUTION: A groove structure is protrudingly provided with protrusions 5 each having a protrusion height d equivalent to a root gap G to be secured, respectively, on both sides of root faces 1a, 2a opposed to each other, and a minute width dimension with respect to the dimension of the root face. Those protrusions are disposed to be shifted with each other at the position in the board thickness direction of a welded member so as to be overlapped in the root gap direction, and the root gap G is secured by using the protrusions as criteria in the state. |
