Study of the Formation Mechanism of A-Segregation Based on Microstructural Morphology

Article
  • 15 Downloads

Abstract

A model that combines a cellular automaton (CA) and lattice Boltzmann method (LBM) is presented. The mechanism of A-segregation in an Fe-0.34 wt pct C alloy ingot is analyzed on the basis of microstructural morphology calculations. The CA is used to capture the solid/liquid interface, while the LBM is used to calculate the transport phenomena. (1) The solidification of global columnar dendrites was simulated, and two obvious A-segregation bands appeared in the middle-radius region between the ingot wall surface and the centerline. In addition, the angle of deflection to the centerline increased with the increasing heat dissipation rate of the wall surface. When natural convection was ignored, the A-segregation disappeared, and only positive segregation was present in the center and bottom corner of the ingot. (2) Mixed columnar–equiaxed solidification was simulated. Many A-segregation bands appeared in the ingot. (3) Global equiaxed solidification was simulated, and no A-segregation bands were found. The results show that the upward movement of the high-concentration melt is the key to the formation of A-segregation bands, and remelting and the emergence of equiaxed grains are not necessary conditions to develop these bands. However, the appearance of equiaxed grains accelerates the formation of vortexes; thus, many A-segregation bands appear during columnar–equiaxed solidification.

Notes

Acknowledgment

This work was funded by the National Science Foundation of China No. 51475138.

References

  1. 1.
    C. Beckermann: Mater. Sci. Technol., 2001, pp. 4733–38.Google Scholar
  2. 2.
    Marburg E: Metals, 1953, pp.157-172.Google Scholar
  3. 3.
    Suzuki K, Miyamoto T: Trans. Iron. Steel. Inst. 1978, vol.18, pp.80-89.Google Scholar
  4. 4.
    Schneider M C, Beckermann C: Metall. Mater. Trans. A. 1995, vol. 26, pp. 2373-2388.CrossRefGoogle Scholar
  5. 5.
    Beckermann C: Int. Mater. Rev. 2002, vol. 47, pp. 243-261.CrossRefGoogle Scholar
  6. 6.
    Wu M H, Könözsy L, Ludwig A, Schützenhöfer W, Ranzer R: Ste. Res. Int. 2008, vol.79, pp. 637-644.CrossRefGoogle Scholar
  7. 7.
    Wu M H, Ludwig A: Metall. Mater. Trans. A. 2006, vol.37, pp. 1613-1631.CrossRefGoogle Scholar
  8. 8.
    Flemings M C: Metall. Trans. 1974, vol.5, pp. 2121-2134.CrossRefGoogle Scholar
  9. 9.
    Flemings M C: Metal. 1976, vol.5, pp. 1-15.Google Scholar
  10. 10.
    Zaloznik M, Combeau H: Int. J. Therm. Sci. 2010, vol.49, pp. 1500-1509.CrossRefGoogle Scholar
  11. 11.
    Li J, Wu M H, Ludwig A, Kharicha A: Int. J. Heat. Mass. Transfer. 2014, vol.72, pp. 668-679.CrossRefGoogle Scholar
  12. 12.
    Bennon W D, Incropera F P: Metall. Trans. B. 1987, vol.18, pp. 611-616.CrossRefGoogle Scholar
  13. 13.
    Mehrabian R, Keane M, Flemings M C: Metall. Mater. Trans. 1970, vol.1, pp. 1209-1220.CrossRefGoogle Scholar
  14. 14.
    Combeau H, Založnik M, Hans S, Richy P E: Metall. Mater. Trans. B.2009, vol.40, pp. 289-304.CrossRefGoogle Scholar
  15. 15.
    Kumar A, Založnik M, Combeau H, Goyeau B, Gobin D: Modelling Simul.Mater.Sci.Eng. 2013, vol.21, pp.045016.CrossRefGoogle Scholar
  16. 16.
    Wu M H, Ludwig A, Kharicha A: Applied Math. Model. 2017, vol.41, pp.102-120CrossRefGoogle Scholar
  17. 17.
    Medina M, Terrail Y DU, Durand F, Fautrelle Y: Metall. Mater. Trans. B. 2004, vol.35, pp.743-754.CrossRefGoogle Scholar
  18. 18.
    Ge H H, Li J, Han X J, Xia M X, Li J G: Mater. Process. Technol. 2016, vol.227, pp.308-317.CrossRefGoogle Scholar
  19. 19.
    Ge H H, Ren F L, Li J, Hu Q D, Xia M X, Li J G: Mater. Process. Technol.2018, vol.252, pp.362-369.CrossRefGoogle Scholar
  20. 20.
    Chopard B, Masselot A: Future. Genera. Compu. Sys. 1999, vol.16, pp.249-257.CrossRefGoogle Scholar
  21. 21.
    Yin H, Felicelli S D, Wang L: Acta Mater. 2011, vol.59, pp.3124-3136.CrossRefGoogle Scholar
  22. 22.
    Sun D K, Zhu M F, Pan S Y, Yang C R, Raabe D: Comput. Math. Appl.2011, vol.61, pp.3585-3592.CrossRefGoogle Scholar
  23. 23.
    Jelinek B, Eshraghi M, Felicelli S, Peters J F: Comput. Phys. Commun. 2014, vol.185, pp.939-947.CrossRefGoogle Scholar
  24. 24.
    Pan S Y, Yang C R, Sun D K, Dai T, Zhu M F: Acta. Metall. Sin. 2009, vol.45, pp.43-45.Google Scholar
  25. 25.
    Guo Z L, Li Q, Zheng C G: Comput. Phys. 2002, vol.19, pp.483-487.Google Scholar
  26. 26.
    Rappaz M, Gandin C A: Acta. Metall. Mater. 1993, vol.41, pp.345-360.CrossRefGoogle Scholar
  27. 27.
    Rappaz M,Thevoz P: Acta. Metall. 1987, vol.35, pp.1487-1497.CrossRefGoogle Scholar
  28. 28.
    Sun D K, Zhu M F, Yang C R, Pan S Y: Acta. Phys. Sin. 2009, vol.58, pp.285-291.Google Scholar
  29. 29.
    Li Q, Beckermann C: Cryst. Growth. 2002, vol.236, pp.482-498.CrossRefGoogle Scholar
  30. 30.
    Prescott P J, Incropera F P: Metall. Mater. Trans. B. 1991, vol.22, pp.529-540.CrossRefGoogle Scholar
  31. 31.
    Lesoult G: Mater. Sci. Eng. A. 2005, vol.413, pp.19-29.CrossRefGoogle Scholar
  32. 32.
    Sun D K, Zhu M F, Dai T, Cao W S, Chen S L, Raabe D, Hong C P: Int. J. Cast. Metals. Res. 2011, vol.24, pp.177-183.CrossRefGoogle Scholar
  33. 33.
    Hu X L, Guo Z L, Zheng C G: Hydrodynam. 2003, vol.2, pp.127–128.Google Scholar
  34. 34.
    Li J, Wu M H, Hao J, Kharicha A, Ludwig A: Comput. Mater. Sci. 2012, vol.55, pp.419-429.CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2018

Authors and Affiliations

  • Zhao Zhang
    • 1
  • Yuchong Bao
    • 1
  • Lin Liu
    • 1
  • Song Pian
    • 1
  • Ri Li
    • 1
  1. 1.School of Materials Science and EngineeringHebei University of TechnologyTianjinChina

Personalised recommendations