Metallurgical and Materials Transactions A

, Volume 50, Issue 5, pp 2201–2217 | Cite as

Microstructural Evolution of Graded Transition Joints

  • Jonathan P. GallerEmail author
  • John N. DuPont
  • Sudarsanam Suresh Babu
  • Mohan Subramanian


Carbon diffusion and the associated microstructural changes in dissimilar metal welds at elevated temperatures lead to a microstructure that is susceptible to premature failure. Graded transition joints (GTJs) can potentially provide a viable replacement to prolong the service life of these components. The purpose of the current investigation is to fabricate, age, and characterize GTJs using three candidate filler metals (Inconel 82, EPRI P87, and 347H) to understand the microstructural evolution at elevated temperatures. Microhardness measurements were performed on the GTJs in the as-welded and aged conditions to understand the initial strength gradients throughout the graded region and how they evolve with aging time. Additionally, energy dispersive spectrometry was performed to measure the compositional gradients, which were input into thermodynamic and kinetic calculations to understand the carbon diffusion behavior and phase stability. Enhanced carbon diffusion occurred at the layer interfaces in the graded region of the GTJ, which indicated important regions that undergo microstructural evolution. The hardness results also revealed hardness changes at the layer interfaces. The analyzed interfaces demonstrated that carbon diffusion and corresponding carbide redistribution occurred that accounted for the observed hardness gradients. Additionally, the transition from a martensitic to austenitic region was observed in each GTJ that contributed to the hardness variations in the graded region. Finally, the formation of a nickel-rich martensitic constituent was observed in the graded region of all filler metals after aging. This constituent was originally austenite at the aging temperature, and transformed to martensite with no change in composition upon cooling. The morphologies of the constituent in the three filler metals are presented and discussed.



  1. 1.
    G. Çam and M. Koçak: Int. Mater. Rev., 1998, vol. 43, pp. 1–44.CrossRefGoogle Scholar
  2. 2.
    G. Çam and M. Koçak: Sci. Technol. Weld. Join., 1998, vol. 3, pp. 159–75.CrossRefGoogle Scholar
  3. 3.
    G. Çam and G. Ipekoglu: Int. J. Adv. Manuf. Technol., 2017, vol. 91, pp. 1851–66.CrossRefGoogle Scholar
  4. 4.
    R.L. Klueh and J.F. King: Weld. J., 1982, 62, pp. 302–11.Google Scholar
  5. 5.
    J.N. DuPont: Int. Mater. Rev., 2012, vol. 57, pp. 208–34.CrossRefGoogle Scholar
  6. 6.
    R. Dooley and P. Chang: Proc. Int. Conf. on Boiler tube failures in fossil plants, 1997, pp. 2–10.Google Scholar
  7. 7.
    I. Ramu and S.C. Mohanty: Procedia Mater. Sci., 2014, vol. 6, pp. 460–7.CrossRefGoogle Scholar
  8. 8.
    M. Bhandari and K. Purohit: IOSR J. Mech. Civ. Eng., 2014, vol. 10, pp. 46–55.CrossRefGoogle Scholar
  9. 9.
    A. Gupta and M. Talha: Prog. Aerosp. Sci., 2015, vol. 79, pp. 1–14.CrossRefGoogle Scholar
  10. 10.
    C.D. Lundin: Weld. J., 1982, 61, p. 58–63.Google Scholar
  11. 11.
    M. Gittos and T. Gooch: Weld. Res. Suppl., 1992, 71, pp. 461–72.Google Scholar
  12. 12.
    G.J. Brentrup and J.N. DuPont: Weld. J., 2013, vol. 92, pp. 72–9.Google Scholar
  13. 13.
    Brentrup, G. J., Snowden, B. S., DuPont, J. N., & Grenestedt, J. L. (2012). Design considerations of graded transition joints for welding dissimilar alloys. Welding Journal, 91, 252-59.Google Scholar
  14. 14.
    N. Sridharan, E. Cakmak, B. Jordan, D. Leonard, W.H. Peter, R.R. Dehoff, D. Gandy, and S.S. Babu: Weld. J., 2017, vol. 96, p. 295-306.Google Scholar
  15. 15.
    J.N. Dupont and A.R. Marder: Metall. Mater. Trans. B, 1996, vol. 27B, pp. 481–9.CrossRefGoogle Scholar
  16. 16.
    J.P. Galler, J.N. Dupont, S.S. Babu, and M. Subramanian: Metall. Mater. Trans. A, 2018.Google Scholar
  17. 17.
    D. Drouin, A.R. Couture, D. Joly, X. Tastet, V. Aimez, and R. Gauvin: 2007, vol. 29, pp. 92–101.Google Scholar
  18. 18.
    A. Borgenstam, L. Höglund, J. Ågren, and A. Engström: J. Phase Equilibria, 2000, vol. 21, pp. 269–80.CrossRefGoogle Scholar
  19. 19.
    Thermo-Calc Software MOB2 TCS Alloy Mobility Database.Google Scholar
  20. 20.
    Thermo-Calc Software TCFE7-TCS Steels/Fe-Alloys Database version 7.Google Scholar
  21. 21.
    Thermo-Calc Software Ni-Data-v7 Ni-Alloys Database.Google Scholar
  22. 22.
    R.L. Klueh: Metall. Trans. A, 1978, vol. 9, pp. 1591–8.CrossRefGoogle Scholar
  23. 23.
    K. Laha, K.S. Chandravathi, K.B.S. Rao, S.L. Mannan, and D.H. Sastry: Metall. Mater. Trans. a, 2001, vol. 32A, pp. 115–24.CrossRefGoogle Scholar
  24. 24.
    J.D. Parker and G.C. Stratford: J. Mater. Sci., 2000, vol. 35, pp. 4099–107.CrossRefGoogle Scholar
  25. 25.
    Y. Zhou, Y. Li, Y. Liu, Q. Guo, C. Liu, L. Yu, C. Li, and H. Li: J. Mater. Res., 2015, vol. 30, pp. 3642–52.CrossRefGoogle Scholar
  26. 26.
    S.W. Banovic, J.N. Dupont, and A.R. Marder: Weld. J., 2001, 80, pp. 63–70.Google Scholar
  27. 27.
    J.N. Dupont and C.S. Kusko: Weld. J., 2007, vol. 86, p. 51s–54s.Google Scholar
  28. 28.
    K.W. Andrews: J. Iron Steel Inst., 1965, 203, pp. 721–27.Google Scholar
  29. 29.
    R.J. Christoffel and M.R. Curran: Weld. J., 1956, vol. 35, 457-468.Google Scholar
  30. 30.
    D.A. Porter, K.E. Easterling, and M.Y. Sherif: Phase Trasformations in Metals and Alloys, Third., Taylor and Francis Group, 2009.Google Scholar
  31. 31.
    L. S. Darken: Metall. Mater. Trans. B, 1948, vol. 41B, 430–38.Google Scholar
  32. 32.
    J.F. Eckel: Weld. J., 1964, vol. 43, 170-78.Google Scholar
  33. 33.
    G. Krauss: Steels: Processing, Structure, and Performance, ASM International, 2015.Google Scholar
  34. 34.
    Sindo K (2003) Welding Metallurgy, Wiley, New York, pp. 822-832.Google Scholar
  35. 35.
    G. Krauss: Mater. Sci. Eng. A, 1999, vol. 273–275, pp. 40–57.CrossRefGoogle Scholar
  36. 36.
    E.C. Bain: Functions of the Alloying Elements in Steel, American Society for Metals, 1939.Google Scholar
  37. 37.
    R.W. Hertzberg, R.P. Vinci, and J.L. Hertzberg: Deformation and Fracture Mechanics of Engineering Materials, Fifth Edit., Wiley and Sons, 2013.Google Scholar
  38. 38.
    W.D. Callister and D.G. Rethwisch: Materials Science and Engineering: An Introduction, vol. 94, Wiley, New York, 2007.Google Scholar
  39. 39.
    I. Hajiannia, M. Shamanian, and M. Kasiri: Mater. Des., 2013, vol. 50, pp. 566–73.CrossRefGoogle Scholar
  40. 40.
    B. Shalchi Amirkhiz, S. Xu, J. Liang, and C. Bibby: in: 36th Annu. CNS Conf.Google Scholar
  41. 41.
    Y. Minami, H. Kimura, and M. Tanimura: J. Mater. Energy Syst., 1985, vol. 7, pp. 45–54.CrossRefGoogle Scholar
  42. 42.
    R. Mittal and B.S. Sidhu: J. Mater. Process. Technol., 2015, vol. 220, pp. 76–86.CrossRefGoogle Scholar
  43. 43.
    T. Sourmail: Mater. Sci. Technol., 2001, vol. 17, pp. 1–14.CrossRefGoogle Scholar
  44. 44.
    H. Tanaka, M. Murata, F. Abe, and K. Yagi: Mater. Sci. Eng. A, 1997, vol. 234–236, pp. 1049–52.CrossRefGoogle Scholar
  45. 45.
    R.L. Klueh and J.F. King: 1981, p. ORNL-5783.Google Scholar
  46. 46.
    E.J. Barrick, D. Jain, J.N. DuPont, and D.N. Seidman: Metall. Mater. Trans. A, 2017, vol. 48, pp. 5890–910.CrossRefGoogle Scholar
  47. 47.
    D. Isheim, A.H. Hunter, X.J. Zhang, and D.N. Seidman: Metall. Mater. Trans. Trans. A, 2013, vol. 44, pp. 3046–59CrossRefGoogle Scholar
  48. 48.
    D. Jain, D. Isheim, X.J. Zhang, G. Ghosh, and D.N. Seidman: Metall. Mater. Trans. A, 2017, vol. 48A, pp. 3642–54.CrossRefGoogle Scholar
  49. 49.
    S.J. Wu, G.J. Sun, Q.S. Ma, Q.Y. Shen, and L. Xu: J. Mater. Process. Technol., 2013, vol. 213, pp. 120–8.CrossRefGoogle Scholar
  50. 50.
    F. Matsuda, K. Ikeuchi, Y. Fukada, Y. Horii, H. Okada, T. Shiwaku, C. Shiga, and S. Suzuki: Transcations JWRI, 1995, vol. 24, pp. 1–24.Google Scholar
  51. 51.
    Y. Li and T.N. Baker: Mater. Sci. Technol., 2010, vol. 26, pp. 1029–40.CrossRefGoogle Scholar
  52. 52.
    C.L. Davis and J.E. King: Mater. Sci. Technol., 1993, vol. 9, pp. 8–15.CrossRefGoogle Scholar
  53. 53.
    X. Li, X. Ma, S. V. Subramanian, C. Shang, and R.D.K. Misra: Mater. Sci. Eng. A, 2014, vol. 616, pp. 141–7.CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2019

Authors and Affiliations

  • Jonathan P. Galler
    • 1
    Email author
  • John N. DuPont
    • 1
  • Sudarsanam Suresh Babu
    • 2
  • Mohan Subramanian
    • 2
  1. 1.Lehigh UniversityBethlehemUSA
  2. 2.University of Tennessee, KnoxvilleKnoxvilleUSA

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