| 摘要 |
Separate segments, oversized to allow for shrinkage during welding, are assembled in the shape of a ring. The segments may be plates carrying guide vanes. The assembled ring is placed in a vacuum chamber and the joints between segments welded by an electron beam. The welding may be carried out in two steps, namely, first track welding the segments together followed by finish welding the entire length of each joint. The segments may be held during welding in a fixture comprising a circular array of radially-slidable jaw elements which carry the separate segments. A clamping ring urges the jaw elements, and hence the segments, radially inwardly, and a cover plate engages the separate segments and urges them radially inwardly so as to clamp the segments together in a ring shape.
|
