Skip to main content
SpringerLink
Log in

The stochastic modeling of solidification structures in alloy 718 remelt ingots

  • Research Summary
  • Melting Technologies
  • Published:
JOM Aims and scope Submit manuscript

Abstract

A stochastic numerical approach was developed to model the formation of grain structure and secondary phases during the solidification of nickel-based alloy 718 remelt ingots. The significance of the present stochastic approach is that the simulated phases can be directly compared with actual phases from experiments at two different scales: grain characteristics can be visualized at the macroscale, while the amount, size, and distribution of secondary phases can be viewed at the microscale. The computer becomes a “dynamic metallographic microscope.” Stochastic modeling was applied to simulate the formation of solidification phases (γprimary phase and NbC and eutectic γ-Laves secondary phases) during the solidification of vacuum-arc-remelted and electroslag-remelted alloy 718 ingots. Modeling results, such as pool profile, grain-growth pattern, grain structure (both columnar and equiaxed grains), columnar-to-equiaxed transition, grain size, and secondary dendrite arm spacing, as well as amount, size, and location of both eutectic γ-Laves and NbC phases compared well with experimental data for cast alloy 718. This research demonstrates that the stochastic approaches are relatively fast, comprehensive, and more accurate than the deterministic approaches in predicting the solidification characteristics of remelt ingots and are mature enough to be used effectively by the metal industry for process development and optimization.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. L. Nastac et al., Proceedings of the 1997 International Symposium on Liquid Metals Processing and Casting, eds. A. Mitchell and P. Aubertin (Sante Fe, NM: AVS, 1997), pp. 145–165.

    Google Scholar 

  2. L. Nastac, S. Sundarraj, and K.O. Yu, Proceedings of the Fourth International Symposium on Superalloy 718, 625, 706 and Various Derivatives, ed. E.A. Loria (Warrendale, PA: TMS, 1997), pp. 55–66.

    Google Scholar 

  3. S. Sundarraj et al., Proceedings of the Modeling of Casting, Welding, and Advanced Solidification Processes VIII (Warrendale, PA: TMS, 1998).

    Google Scholar 

  4. J. Gleick, Chaos—Making a New Science (New York: Penguin Books, 1987).

    Google Scholar 

  5. COMPACT™ (Minneapolis, MN: Innovative Research)

  6. M. Rappaz and Gh.A. Gandin, Acta Metall., 41 (2) (1993), pp. 345–360.

    Article  CAS  Google Scholar 

  7. L. Nastac, Ph.D. dissertation, University of Alabama, Tuscaloosa (1995).

    Google Scholar 

  8. L. Nastac and D.M. Stefanescu, Modelling Simul. Mater. Sci. Eng., 5 (1997), pp. 391–420.

    Article  CAS  Google Scholar 

  9. M.P. Anderson et al., Acta Metall., 32 (5) (1991), pp. 783–791.

    Google Scholar 

  10. H.W. Hesselbarth and I.R. Goebel, Acta Metall., 39 (9) (1991), pp. 2135–2143.

    Article  CAS  Google Scholar 

  11. D.M. Stefanescu, Modeling of Casting, Welding and Advanced Solidification Processes VI, ed. T.S. Piwonka et al. (Warrendale, PA: TMS, 1993), pp. 3–20.

    Google Scholar 

  12. D.M. Stefanescu and H. Pang, Proceedings of the International Symposium by the Computer Applications Committee of the Metallurgical Society of CIM, eds. S.A. Argyropoulus and F. Mucciardi (Montreal: CIM, 1996), pp. 164–176.

    Google Scholar 

  13. H. Pang and D.M. Stefanescu, Solidification Science and Processing, eds. I. Ohnaka and D. M. Stefanescu (Warrendale, PA: TMS, 1996).

    Google Scholar 

  14. G.K. Upadhya et al., Modeling of Casting, Welding and Advanced Solidification Processes, eds. M. Cross and J. Campbell (Warrendale, PA: TMS, 1995), pp. 517–524.

    Google Scholar 

  15. L. Nastac and D.M. Stefanescu, Met. Mat. Trans., 28A (1997), pp. 1582–1587.

    Article  CAS  Google Scholar 

  16. B. Radhakrishnan and R.G. Thompson, Met. Trans., 22A (1991), pp. 887–902.

    CAS  Google Scholar 

  17. C. Chen, R.G. Thompson, and D.W. Davis, Superalloys 718, 625 and Various Derivatives, ed. E.A. Loria (Warrendale, PA: TMS, 1991), pp. 81–96.

    Google Scholar 

  18. L. Nastac and D.M. Stefanescu, Met. Mat. Trans., 27A (1996), pp. 4061–4074.

    Article  CAS  Google Scholar 

  19. L. Nastac and D.M. Stefanescu, Met. Mat. Trans., 27A (1996), pp. 4075–4083.

    Article  CAS  Google Scholar 

  20. L. Nastac and D.M. Stefanescu, Modeling of Casting, Welding and Advanced Solidification Processes VI, eds. T.S. Piwonka et al. (Warrendale, PA, TMS, 1993), pp. 209–218.

    Google Scholar 

  21. L. Nastac and D.M. Stefanescu, AFS Trans. (1996), pp. 425–434.

  22. L. Nastac and D.M. Stefanescu, Met. Trans., 24A (1993), 2107–2118.

    CAS  Google Scholar 

  23. K.O. Yu and H.D. Flanders, Proceedings of the Vacuum Metallurgy Conference on Specialty Metals, Melting and Processing (Pittsburgh, PA: AVS, 1984), pp. 107–118.

    Google Scholar 

  24. K.O. Yu, Proceedings of the Vacuum Metallurgy Conference on Specialty Metals, Melting and Processing (Pittsburgh, PA: AVS, 1984), pp. 83–92.

    Google Scholar 

  25. K.O. Yu, internal report, Special Metals Corporation (1982).

  26. J.S. Chou et al., private communication, Concurrent Technologies Corporation (1997).

  27. J.F. Radavitch, Proceedings of the Fourth International Symposium on Superalloy 718, 625, 706 and Various Derivatives, ed. E.A. Loria (Warrendale, PA: TMS, 1997), pp. 17–26.

    Google Scholar 

  28. A. Haji-Sheikh and E.M. Sparrow, J. of Heat Transfer, 89 (1967), pp. 121–131.

    CAS  Google Scholar 

  29. A. Haji-Sheikh and F.P. Buckingham, J. of Heat Transfer, 115 (1993), pp. 26–33.

    Article  Google Scholar 

  30. A. Haji-Sheikh and R. Lakshminarayanan, Proc. Int. Symp. On Cooling Technology for Electronic Equipment (Hawaii, 1987), pp. 550–564.

  31. T.J. Hofmann and N.E. Banks, Nuclear Sci. and Engrg., 59 (1976), pp. 205–214.

    Google Scholar 

  32. A. Haji-Sheikh and E.M. Sparrow, J. SIAM Appl. Math., 14 (1966), pp. 370–389.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Concurrent Technologies Corporation, 1450 Scalp Avenue, 15904, Johnstown, Pennsylvania

    Laurentiu Nastac

Authors
  1. Laurentiu Nastac
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Suresh Sundarraj
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Kuang-O Yu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Yuan Pang
    View author publications

    You can also search for this author in PubMed Google Scholar

Additional information

Laurentiu Nastac earned his Ph.D. in metallurgical and materials engineering at the University of Alabama at Tuscaloosa in 1995. He is currently a senior staff engineer at Concurrent Technologies Corporation. Dr. Nastac is a member of TMS.

Suresh Sundarraj earned his Ph.D. in mineral engineering at the University of Minnesota in 1994. He is currently a process modeling engineer for Concurrent Technologies Corporation. Dr. Sundarraj is also a member of TMS.

Kuang-O Yu earned his Ph.D. in metallurgical engineering at the University of Kentucky in 1978. He is currently director of research and development at RMI Titanium Company. Dr. Yu is also a member of TMS.

Yuan Pang earned his M.S. in mechanical engineering at the University of Akron in 1977. He is currently a principal engineer at Concurrent Technologies Corporation.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Nastac, L., Sundarraj, S., Yu, KO. et al. The stochastic modeling of solidification structures in alloy 718 remelt ingots. JOM 50, 30–35 (1998). https://doi.org/10.1007/s11837-998-0376-5

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11837-998-0376-5

Keywords

Search

Navigation