The Effects of Chemistry Variations in New Nickel-Based Superalloys for Industrial Gas Turbine Applications
Sabin Sulzer, Magnus Hasselqvist, Hideyuki Murakami, Paul A.J. Bagot, Michael P. Moody, Roger C. Reed
Abstract
Abstract Industrial gas turbines (IGT) require novel single-crystal superalloys with demonstrably superior corrosion resistance to those used for aerospace applications and thus higher Cr contents. Multi-scale modeling approaches are aiding in the design of new alloy grades; however, the CALPHAD databases on which these rely remain unproven in this composition regime. A set of trial nickel-based superalloys for IGT blades is investigated, with carefully designed chemistries which isolate the influence of individual additions. Results from an extensive experimental characterization campaign are compared with CALPHAD predictions. Insights gained from this study are used to derive guidelines for optimized gas turbine alloy design and to gauge the reliability of the CALPHAD databases.