Abstract
With a combination of high strength , toughness and resistance to corrosion, INCONEL® alloy 725 has been widely used in marine, aerospace, and land-based power industries. Typically, the alloy presents a conventional precipitate-strengthened γ-γ′/γ″ microstructure when appropriate aging treatments are employed. Although the corrosion resistance of INCONEL® alloy 725 is significant, its use is limited to relatively low temperatures when compared to other γ′ precipitate-strengthened Ni-based superalloys . This can limit the use of the alloy as turbine engine components or in other power-generation applications since future engine designs suggest increases in the operating temperature . This investigation aims at modifying the composition of the alloy to assess its high-temperature mechanical properties . Variations to the Ti /Al ratio were considered with respect to the precipitate phases stability as well as additions of Ta and Nb. Thermodynamic and kinetic predictions, such as phase fraction/stability and time–temperature –transformation diagrams, were used to help in the design process and were validated experimentally. The various compositions and relative aging treatments investigated produced microstructures differing in grain boundary phases and γ′ precipitate sizes and fractions. Tensile and creep testing were performed and the effect of the various compositions and microstructures on the mechanical performance of the modified INCONEL® 725 alloys was examined.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Online document. http://www.specialmetals.com/assets/smc/documents/alloys/inconel/inconel-alloy-725.pdf. Accessed 26 Sept 2017
Shoemaker LE (2005) Alloys 625 and 725: trends in properties and applications. In: Loria ED (ed) Superalloys 718, 625, 706 and derivatives 2005. Wiley, Hoboken, NJ, pp 409–418
Online document. http://www.specialmetals.com/assets/smc/documents/inconel_alloy_718.pdf. Accessed 7 Oct 2017
Mannan S, Veltry F (2001) Time-Temperature-Transformation diagram of alloy 725. In: Loria ED (ed) Superalloys 718, 625, 706 and various derivatives. Wiley, Hoboken, NJ, pp 345–356
Reed RC (2006) The superalloys: fundamentals and applications. Cambridge University Press, New York
Detrois M et al (2014) Precipitate phase stability in γ-γ′-δ-η Ni-base superalloys. JOM 66:2478–2485
Antonov S et al (2015) Precipitate phase stability and compositional dependence on alloying additions in γ-γ′-δ-η Ni-base superalloys. J. Alloys Compd. 626:76–86
Rath M, Povoden-Karadeniz E, Kozeschnik E (2016) Precipitation kinetic modeling of the new eta-phase Ni6AlNb in Ni-base superalloys. In: Hardy M, Huron E, Glatzel U, Griffin B, Lewis B, Rae C, Seetharaman V, Tin S (eds) Superalloys 2016: proceedings of the 13th international symposium on superalloys. Wiley, Hoboken, NJ, pp 97–105
Hibner EL, Sizek HW, Mannan SK (1997) Elevated temperature tensile and creep rupture. In: Loria ED (ed) Superalloys 718, 625, 706 and various derivatives. Wiley, Hoboken, NJ, pp 491–501
Anderson JO et al (2002) Thermo-calc and DICTRA computational tools for materials science. Calphad 26:273–312
Detrois M, Jablonski PD (2017) Trace element control in binary Ni-25Cr and ternary Ni-30Co-30Cr master alloy casting. In: Krane MJM, Ward MR, Rudoler S, Elliott AJ, Patel A (eds) Proceedings of the liquid metal processing & casting conference 2017, Philadelphia, p 75–84. https://doi.org/10.2172/1406915
Jablonski PD, Cretu M, Nauman J (2017) Considerations for the operation of a small scale ESR furnace. In: Krane MJM, Ward MR, Rudoler S, Elliott AJ, Patel A (eds) Proceedings of the liquid metal processing & casting conference 2017, Philadelphia, p 157–162
Jablonski PD, Hawk JA (2017) Homogenizing advanced alloys: thermodynamic and kinetic simulations followed by experimental results. J Mater Eng Perform 26:4–13
ASTM E8/E8 M-16a (2016) Standard test methods for tension testing of metallic materials. ASTM International, West Conshohocken, PA
ASTM E139-11 (2011) Standard test methods for conducting creep, creep-rupture, and stress-rupture tests of metallic materials. ASTM International, West Conshohocken, PA
Schneider CA, Rasband WS, Eliceiri KW (2012) NIH Image to imageJ: 25 years of image analysis. Nat Methods 9:671–675
Goldhoff RM, Hahn GJ (1968) Correlation and extrapolation of creep-rupture data of several steels and superalloys using time-temperature parameters. ASM Publication D8-100; American Society for Metals, Cleveland, OH, p 199–247
Morral FR (1984) Wrought Superalloys. Superalloys source book. ASM International, Metals Park, OH, pp 20–40
Hong HU et al (2009) The effect of grain boundary serration on creep resistance in a wrought nickel-based superalloy. Mater Sci Eng A 517:125–131
Azadian S, Wei L-Y, Warren R (2004) Delta phase precipitation in Inconel 718. Mater Charact 53:7–16
Unocic KA, Shingledecker JP, Tortorelli PF (2014) Microstructural changes in Inconel® 740 after long-term aging in the presence and absence of stress. JOM 66:2535–2542
Antonov S et al (2015) Comparison of thermodynamic database models and APT data for strength modeling in high Nb content γ-γ′ Ni-base superalloys. Mater Des 86(649):655
Acknowledgements
This technical effort was performed in support of the National Energy Technology Laboratory’s ongoing research in advanced alloy development under the RES contract DE-FE-0004000. The authors would like to thank Mr. Edward Argetsinger and Mr. Joseph Mendenhall for assistance in melting, and Mr. Christopher Powell for mechanical testing.
Disclaimer This project was funded by the Department of Energy, National Energy Technology Laboratory, an agency of the United States Government, through a support contract with AECOM. Neither the United States Government nor any agency thereof, nor any of their employees, nor AECOM, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2018 The Minerals, Metals & Materials Society
About this paper
Cite this paper
Detrois, M., Rozman, K.A., Jablonski, P.D., Hawk, J.A. (2018). Compositional Design and Mechanical Properties of INCONEL® Alloy 725 Variants. In: Ott, E., et al. Proceedings of the 9th International Symposium on Superalloy 718 & Derivatives: Energy, Aerospace, and Industrial Applications. The Minerals, Metals & Materials Series. Springer, Cham. https://doi.org/10.1007/978-3-319-89480-5_26
Download citation
DOI: https://doi.org/10.1007/978-3-319-89480-5_26
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-89479-9
Online ISBN: 978-3-319-89480-5
eBook Packages: Chemistry and Materials ScienceChemistry and Material Science (R0)