Gas Turbine Bucket Corrosion Protection Developments

Abstract

This paper describes a joint General Electric/ARAMCO program for improving rotating gas turbine parts lives in desert environments with high concentrations of alkali salts and sulfur-containing fuels. A description of the environment is given along with a definition of the hot corrosion problem. A series of buckets coated with experimental or developmental coatings produced by a variety of processes such as pack cementation, physical vapor deposition, plasma spray and sheet claddings are described and results from actual field trials are discussed. Pt-Cr-Al pack cementation coatings were observed to perform well. Next generation overlay coatings of the MCr-AlY-type applied by plasma spraying electron beam and sheet cladding processes also performed well.