| 摘要 |
<p>In the preparation of plane or curved workpieces for welding together by means of an electron beam and wherein the weld takes the form of a full penetration joint, fusion lips are provided at the place where the lower welding bead forms. In the case where the workpieces are constituted by rotationally symmetrical thick-walled hollow bodies such as rotor discs for construction of turbo-machines which upon welding together form a closed cavity, the fusion lips have an annular configuration and are located at the inner radial contour of the welding interface. The workpieces are also provided with an arrangement for centering the lips and a metal foil is inserted between the lips to improve the toughness of the weld material, the foil having a carbon content lower than that of the parent metal of the workpieces.</p> |
