Developing Alloy Compositions for Future High Temperature Disk Rotors

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Authors

  • M. C. Hardy
  • C. Argyrakis
  • H. S. Kitaguchi
  • A. S. Wilson
  • R. C. Buckingham
  • K. Severs
  • C. Jackson
  • E. J. Pickering
  • C. Papadaki
  • K. A. Christofidou
  • P. M. Mignanelli
  • A. Evans
  • D. J. Child
  • N. G. Jones
  • C. M.F. Rae
  • H. J. Stone

External organisations

  • Rolls Royce PLC
  • University of Cambridge
  • Allegheny Technologies Incorporated (ATI) Forged Products Cudahy
  • University of Manchester
  • University of Oxford
  • BAM Federal Institute for Materials Research and Testing

Abstract

Two new alloy compositions for possible disk rotor applications have been examined. Both were intended to have higher γ content than the existing alloy, RR1000, and be produced using powder metallurgy and isothermal forging to enable forgings to show a consistent coarse grain microstructure. Small pancake forgings of the new alloys and RR1000 were made and from these, blanks were cut, solution heat treated, cooled at measured rates and aged. Results of screening tests to understand the tensile, creep and dwell crack growth behavior, oxidation resistance and phase stability of these new alloys and coarse grain RR1000 are reported. The development alloys were similar in composition but exhibited different tensile and creep properties, phase stability and resistance to oxidation damage. Despite attempts to minimize variation in microstructure from heat treatment, differences in γ size distribution were found to influence tensile and creep behavior. One of the new alloys (Alloy 2) showed improved yield and tensile strength compared to RR1000. Alloy 2 displayed similar initial creep strain behavior to RR1000 but superior resistance to subsequent creep damage, producing longer creep rupture lives. All of the alloys showed crack retardation at low stress intensity factor ranges (ΔK) from 3600 s dwell cycles at 700 °C in air. This occurred whilst crack growth was intergranular. Alloy 1 was found to precipitate C14 Laves phase from long term exposure at 800 °C. Like RR1000, σ phase was not detected in the new alloys after 750 h at 800 °C.

Details

Original languageEnglish
Title of host publicationSuperalloys 2020 - Proceedings of the 14th International Symposium on Superalloys
EditorsSammy Tin, Mark Hardy, Justin Clews, Jonathan Cormier, Qiang Feng, John Marcin, Chris O'Brien, Akane Suzuki
Publication statusPublished - 2020
Event14th International Symposium on Superalloys, Superalloys 2021 - Seven Springs, United States
Duration: 12 Sep 202116 Sep 2021

Publication series

NameMinerals, Metals and Materials Series
ISSN (Print)2367-1181
ISSN (Electronic)2367-1696

Conference

Conference14th International Symposium on Superalloys, Superalloys 2021
CountryUnited States
CitySeven Springs
Period12/09/2116/09/21

Keywords

  • CALPHAD, Material properties, Phase stability, Powder metallurgy