AbstractThe design life for blades of large stationary gas turbines is at least 100000 h in creep terms. Typical damage occurring within the lifetime of gas-turbine blading may be hot corrosion and/or erosion, foreign-object damage, tip rubbing, and cracking caused by low-cycle fatigue, thermocycle fatigue, high-cycle fatigue, and creep crack growth. When applying refurbishing procedures both technical and economic aspects should be considered. The repair procedures available are welding, brazing, plasma spraying, recoating, combined with special heat treatment cycles, and occasionally intermediate hot isostatic pressing. The limiting factors for repair procedures are the mechanical properties and the hot corrosion behaviour of the refurbished parts. Examples are given of results from metallographic and laboratory tests on refurbished Kraftwerk Union (KWU) test specimens and blades in relation to the material, design, and stressing of the components. Typical examples of the refurbished parts are also presented. Service experience with refurbished blades in stationary gas turbines is limited at present. Therefore, KWU can only consider these procedures in the light of the growing knowledge of refurbishing processes and the operating experience of refurbished parts as well as the economic aspects.MST/102