This paper describes the ongoing results being obtained from a joint General Electric/ARAMCO program to improve gas turbine bucket corrosion lives in desert environments involving high concentrations of alkali salts and sulfur-containing fuels. The program has involved the insertion of buckets coated with a variety of experimental or developmental coatings into several General Electric MS-5002 gas turbines being operated by ARAMCO in the Eastern Province of Saudi Arabia. Buckets coated by a variety of process techniques, such as pack cementation, physical vapor deposition, plasma spray and sheet cladding, have been evaluated during this program. Service life on some of these coated buckets has now reached approximately 35,000 hr. In general, Pt-Cr-Al pack cementation coatings have been observed to perform well, with the Pt being critical for superior long-time service.

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