GT26 2006 Turbine Stage 1 Blade Reconditioning Development and Qualification at Ansaldo Repair Centre

Abstract

The evolution of industrial gas turbines towards increased efficiency and performance requires even higher operating temperatures for the engines. In order to remain competitive in the market, OEM companies continuously need to develop maintenance programs and repair technologies able to extend the life of these components as much as possible. The repair technology improvement is fundamental to reduce scrap rates and maintenance costs to be competitive on the market. The Ansaldo Repair Centre answers to this market demand by providing advanced and competitive repair techniques and an increasing broad repair portfolio to its customers. This paper describes the steps and approach to determine the repair process of GT26 LPT Blade 1 in order to allow the component to run another service interval. The base material status and the indication found after service was used as the foundation for a development of a dedicated repair sequence from stripping, to suitable heat treatments, to enhanced repair technique to recoating of the blade. Particular attention was paid to the most damaged area, for which a particular welding procedure including an optimized filler material has been applied for the rebuilding of the tip and platform zones as well as for the restoration of the unique tip closing features.