Operating conditions and materials selection and development in gas turbines

Abstract

This paper consists of two parts. In the first part, concerning operational conditions in gas turbines, the following topics are covered: - the magnitude of temperatures, temperature profiles, and stresses in various components - transient temperature conditions, occuring as a result of e.g. throttle setting changes and affecting thermal fatigue life - electrochemical corrosion, oxidation, hot corrosion, and erosion, as well as the factors which will promote these types of attack, including atmospheric pollutants and fuel contaminants. In the second part, which concerns material selection and application, the following items are considered: - the establishment of material selection criteria regarding compressor components, flame tubes, turbine blades, vanes and discs - an overview of the currently applied materials and the trend in materials development for future application, including directionally solidified eutectics, oxide-dispersion-strengthened alloys, fibre-reinforced superalloy composites and ceramics - the introduction and development of new production processes, like directional solidification, single crystal blade processing and powder metallurgy