Exploring Options for Simultaneously Reducing Cost and Improving Weldability of Nickel-Based Alloys for Advanced Power Generation

Thursday, February 27, 2025: 2:45 PM
Indian Wells I (Grand Hyatt Indian Wells Resort)
Ms. Sophie Mehl , Michigan Technological University, Houghton, MI
Dr. Paul G. Sanders , Michigan Technological University, Houghton, MI
Dr. Tanner Olson , Michigan Technological University, Houghton, MI
Dr. John Shingledecker, Ph.D., FASM , Electric Power Research Institute, Charlotte, NC
Anna Cole , Michigan Technological University, Houghton, MI

Title: Exploring options for simultaneously reducing cost and improving weldability of nickel-based alloys for advanced power generation

Authors: MTU-Sophie Mehl, Tanner Olson, Paul Sanders, EPRI- John Shingledecker, Shutong Zhang

Abstract

To advance sustainability efforts, electric power plants have reduced specific carbon dioxide emissions by increasing operating temperatures and pressures to improve power generation efficiency. The latest improvements are focused on advanced ultra-supercritical (A-USC) steam and supercritical carbon dioxide (sCO2) power generation operating above 700oC. To meet these challenging conditions, nickel superalloys are used in the highest temperature components; however, they are expensive and present weldability challenges. In this work, integrated computational materials engineering (ICME) alloy design strategies using computational thermodynamics and kinetics coupled with multi-objective Bayesian optimization (MOBO) were employed to optimize a nickel superalloy composition to simultaneously improve material weldability and decrease cost without compromising high-temperature creep strength. This is based in part on the use of the Ni3Ti eta (h) phase as an alternative strengthening phase compared to gamma prime (g'). Three selected compositions were cast, forged, and rolled for experimental study, and their microstructures and mechanical properties were compared to common nickel superalloys (263, Waspaloy, 740H).  Weldability was experimentally assessed using laboratory based solidification cracking and relaxation cracking experiments. Hot hardness was used to screen for material strength. The results are compared to the key computational design indices for performance. The findings will discuss the uses and limitations of the demonstrated ICME design approach and the practical potential for these lower cost eta phase strengthened alloys to be a viable replacement for some nickel superalloys in advanced energy applications.

 

See more of: Nickel-Based/Superalloy: Developments
See more of: Technical Program