| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for welding an impeller, which can reduce or simplify finishing work of weld beads and also secure a necessary strength of weld joints, while improving work efficiency in build-up welding and reducing weld distortion. <P>SOLUTION: A groove 14 with a designated depth and width facing to a vane 13 is formed on an opposite side of side plate 12 to which the vane 13 is butt-welded. Laser beam 21 is irradiated to the bottom part 14a of the groove 14 and penetration welding is performed on both the groove bottom 14a and the end of vane 13 so that a bead portion 4 generated on the back side forms a concave face in its inside. Then, the build-up welding is conducted providing filler metal 8 in a molten portion while scanning the laser beam 21 at the groove bottom 14a. In the operation, a converging spot 211 of the laser beam 21 is set to form a narrow rectangle. During the penetration welding process, the long side of the converging spot 211 is set parallel or inclined by a designated angle to the longitudinal direction of the groove 14. During the welding process, the long side of the converging spot 211 is set so as to be inclined to the longitudinal direction of the groove 14 by a different angle from that of the penetration welding process. <P>COPYRIGHT: (C)2009,JPO&INPIT |
