Method of restoring worn turbine components

Abstract

The method of restoring the worn edge surfaces of the shroud portion of a turbine component, such as a blade of the type having a ribbed mounting base at one end, which involves the steps of applying welding material to the worn edges of the shroud portion so as to build up the same beyond the dimensions of the shroud of a new component, and thereafter clamping the blade by its base in a fixture having a reference surface with a fixed position-relationship with respect to one edge of the shroud of a new blade of the type being refurbished when said new blade is similarly clamped in the fixture, and grinding off the added or overlay metal from the one edge of the built-up shroud until such edge is restored and duplicates the fixed relationship with respect to the reference surface. Thereafter the blade is clamped in a second fixture which has a supporting surface so arranged as to back up the one restored edge and thereby accurately position the blade with respect to the fixture, and then a remaining one of the built-up edges is restored. Finally, the blade is clamped in a third fixture having multiple surfaces backing up respectively the one restored edge and the remaining restored edge, while a third edge of the shroud is resurfaced. The method is characterized by high accuracy and good repeatability; excellent uniformity between successive units being refurbished thereby results.