METHOD FOR PREVENTING OVERLAP OF ADJACENT SHROUD COVERS AT TIP OF TURBINE BUCKET

摘要

PURPOSE: A method for preventing the overlap of adjacent shroud covers at the tip of a turbine bucket is provided to preclude shroud cover overlap during a turbine operation by building up weld material along the inside radial surface of the overlapping cover adjacent to the overlapped edge of the adjoining cover and increasing the thickness of the overlapping cover. CONSTITUTION: A method for preventing the overlap of adjacent shroud covers(14a,14b) at the tip of a turbine bucket is composed of steps for increasing the radial extent of one of the adjacent shroud covers adjacent to an edge thereof to a location substantially in circumferential registration with another of the adjacent shroud covers; forming a weld material along a portion of a radial facing surface adjacent to the edge of one shroud cover; and forming a first weld material of a predetermined hardness adjacent to the edge and a second weld material of a lesser hardness than the first weld material on a side of the first weld material remote from the edge.