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Analyses of Creep Properties of Ni-base Superalloy Powders as Cooling Rate after Solid Solution Heat Treatment

니켈기 초내열합금 분말의 고용화 열처리 후 냉각속도에 따른 크리프특성 분석

  • Received : 2016.05.18
  • Accepted : 2016.06.20
  • Published : 2016.06.28

Abstract

In this study, solid solution heat treatment of consolidated nickel-based superalloy powders is carried out by hot isotactic pressing. The effects of the cooling rate of salt quenching, and air cooling on the microstructures and the mechanical properties of the specimens are analyzed. The specimen that is air cooled shows the formation of serrated grain boundaries due to their obstruction by the carbide particles. Moreover, the specimen that is salt quenched shows higher strength than the one that is air cooled due to the presence of fine and close-packed tertiary gamma prime phase. The tensile elongation at high temperatures improves due to the presence of grain boundary serrations in the specimen that is air cooled. On the contrary, the specimen that is salt quenched and consists of unserrated grain boundaries shows better creep properties than the air cooled specimen with the serrated grain boundaries, due to the negative creep phenomenon.

Keywords

Nickel-base superalloy;Solid solution heat treatment;Negative creep;Powder metallurgy;Electron back scatter diffraction

References

  1. W. F. Smith: Structure and Properties of engineering Alloys, McGraw-Hill, INC., New York (1993) 490.
  2. C. T. Sims and W. C. Hagel: Superalloys II, Wiley, INC., New York (1987) 3.
  3. K. Shigemitu and Y. Saiga: Metall. Trans. A, 11A (1980) 1019.
  4. J. H. Lee: The effect of B and Zr addition on the microstructural and mechanical properties in two-phase (NiAl+Ni3Al) alloy, KAIST (1997) (korean).
  5. R. M. German: Powder metallurgy & Particulate Materials Processing, Metal Powder Industry, German (2005) 67.
  6. D. S. Stolz and E. Gerhard: Effect of A supersolvus Heat Treatment on the Microstructure and Mechanical Properties of A Power Metallurgy Processed Nickel-Base Superalloy, Florida University (2004).
  7. O. H. U. Hong: Mater. Sci. Eng. A, 517 (2009) 125. https://doi.org/10.1016/j.msea.2009.03.071
  8. O. Miyagawa: Superalloys (1976) 245.
  9. C. Ducrocq and Y. Honnorat: Superalloys, The Metallurgical Society (1988) 70.
  10. J. T. Sun and Y. D. Kim: Microstructure and Mechanical Properties of Inconel 617 Degraded at High Temperature, Han-Yang University (2007) (korean).
  11. K. Chen, L.R. Zhao and J. S. Tse: Mater. Sci. Eng. A, 360 (2003) 197. https://doi.org/10.1016/S0921-5093(03)00464-7
  12. F. Louchet: Scr. Metall. Mater., 33 (1995) 6.

Acknowledgement

Supported by : 방위사업청