Water-Cooled Gas Turbine Monometallic Nozzle Development

Abstract

This paper describes the materials and processes development required to fabricate the second stage monometallic water-cooled nozzle for the Department of Energy funded High Temperature Turbine Technology (HTTT) program. Materials engineering and development work including alloy selection, hot isostatic pressing (HIP), and heat treat optimization necessary to fabricate this component is described and the results of this work are reported. Specialized processes utilized to achieve tight design tolerances such as TRW’s split mold investment casting and shaped tube electrode machining (STEM) are also described. The advantages of these processes are discussed in terms of the overall component design goals.