| 摘要 |
<p>PURPOSE:To improve the strength of root of a runner blade by removing a section, in which a high stress is generated, is removed and the section is buried with a metallic material. CONSTITUTION:When the roots of respective runner blades 3, attached to a runner crown 2 and a runner band 4, are divided equally into 10 equal intervals along the blade 3, a range from 5.5 to 9.0 at the side of the crown and the range from 6.5 to 9.0 at the side of the band are the range whrein the level of stress is high. Accordingly, that area is removed partially by chipping or the like. The removed section is buried with a metal by welding. Subsequently, stress removing annealing is applied thereon to remove the stress remaining due to the welding.</p> |
