|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Materials for High Temperature Applications: Next Generation Superalloys and Beyond
||Gamma-Prime Strengthened Superalloys for Heavy Duty Gas Turbine Applications
||Andrew Detor, Reza Sharghi-Moshtaghin, Ning Zhou, Shenyan Huang, Richard DiDomizio
|On-Site Speaker (Planned)
Increasing combined cycle turbine efficiency beyond 65% requires a new heavy duty rotor material capable of operating at temperatures well in excess of today's H-class levels. Current alloys are limited by the stability of their major strengthening phase, gamma double prime, which coarsens and may convert to delta in service at high temperature. The gamma prime phase is more suited for strengthening in this application; however, gamma prime rapidly overages during the slow cooling rates inherent in processing thick-section gas turbine components. In the present work we are developing two new alloying strategies to control the coarsening of gamma prime during slow cooling. In one approach we use controlled coprecipitation to limit growth, and in the other we modify gamma prime chemistry to reduce coarsening kinetics. Microstructure and mechanical properties will be presented and discussed in the context of enabling a 650˚C+ capable heavy duty gas turbine rotor.