Study on the Microstructure and Liquid Phase Formation in a Semisolid Gray Cast Iron

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The development of high-quality semisolid raw materials requires an understanding of the phase transformations that occur as the material is heated up to the semisolid state, i.e., its melting behavior. The microstructure of the material plays a very important role during semisolid processing as it determines the flow behavior of the material when it is formed, making a thorough understanding of the microstructural evolution essential. In this study, the phase transformations and microstructural evolution in Fe2.5C1.5Si gray cast iron specially designed for thixoforming processes as it was heated to the semisolid state were observed using in situ high-temperature confocal laser scanning microscopy. At room temperature, the alloy has a matrix of pearlite and ferrite with fine interdendritic type D flake graphite. During heating, the main transformations observed were graphite precipitation inside the grains and at the austenite grain boundaries; graphite flakes and graphite precipitates growing and becoming coarser with the increasing temperature; and the beginning of melting at around 1413 K to 1423 K (1140 °C to 1150 °C). Melting begins with the eutectic phase (i.e., the carbon-rich phase) and continues with the primary phase (primary austenite), which is consumed as the temperature increases. Melting of the eutectic phase composed by coarsened interdendritic graphite flakes produced a semi-continuous liquid network homogeneously surrounding and wetting the dendrites of the solid phase, causing grains to detach from each other and producing the intended solid globules immersed in liquid.

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  1. 1.

    [1] D.B. Spencer, R. Mehrabian and M.C. Flemings: Metall. Trans., 1972, vol. 3, pp. 1925–32. doi:10.1007/BF02642580

  2. 2.

    [2] H.V. Atkinson: Prog. Mater. Sci., 2005, vol. 50, pp. 341–412. doi: 10.1016/j.pmatsci.2004.04.003

  3. 3.

    [3] M.C. Flemings: Metall. Trans. B, 1991, vol. 22, pp. 269–93. doi: 10.1007/BF02661090

  4. 4.

    [4] S. Zabler, A. Ershov, A. Rack, F. Garcia-Moreno, T. Baumbach and J. Banhart: Acta Mater., 2013, vol. 61, pp. 1244–53. doi: 10.1016/j.actamat.2012.10.047

  5. 5.

    [5] B. Cai, S. Karagadde, L. Yuan, T.J. Marrow, T. Connolley and P.D. Lee: Acta Mater., 2014, vol. 76, pp. 371–80. doi: 10.1016/j.actamat.2014.05.035

  6. 6.

    [6] T. Werz, M. Baumann, U. Wolfram and C.E. Krill III: Mater. Charact., 2014, vol. 90, pp. 185–95. doi: 10.1016/j.matchar.2014.01.022

  7. 7.

    [7] K. Du, Q. Zhu, D. Li and F. Zhang: Mater. Charact., 2015, vol. 106, pp. 134–40. doi: 10.1016/j.matchar.2015.05.035

  8. 8.

    [8] D. Phelan, N. Stanford and R. Dippenaar: Mater. Sci. Eng. A, 2005, vol. 407, pp. 127–34. doi: 10.1016/j.msea.2005.07.015

  9. 9.

    [9] D. Zhang, H. Terasaki and Y. Komizo: Acta Mater., 2010, vol. 58, pp. 1369–78. doi: 10.1016/j.actamat.2009.10.043

  10. 10.

    [10] M.M. Attallah, H. Terasaki, R.J. Moat, S.E. Bray, Y. Komizo and M. Preuss: Mater. Charact., 2011, vol. 62, pp. 760–67. doi: 10.1016/j.matchar.2011.05.001

  11. 11.

    Y. Komizo and H. Terasaki (2010) In situ study of phase transformation in steel during welding. In: T. Kannengiesser, S.S. Babu, Y. Komizo and A.J. Ramirez (Eds.), In situ studies with photons, neutrons and electrons scattering. Springer, Berlin, pp. 1–11. doi: 10.1007/978-3-642-14794-4_1

  12. 12.

    [12] I. Sohn and R. Dippenaar: Metall. Mater. Trans. B, 2016, vol. 47, pp. 2083–94. doi: 10.1007/s11663-016-0675-0

  13. 13.

    [13] G.C. Gu, R. Pesci, L. Langlois, E. Becker, R. Bigot and M.X. Guo: Acta Mater., 2014, vol. 66, pp. 118–31. doi: 10.1016/j.actamat.2013.11.075

  14. 14.

    [14] X.G. Hu, Q. Zhu, H.X. Lu, F. Zhang, D.Q. Li and S.P. Midson: J. Alloy. Compd., 2015, vol. 649, pp. 204–10. doi: 10.1016/j.jallcom.2015.07.121

  15. 15.

    S.P Midson: Solid State Phenom., 2015, vol. 217-218, pp. 487–95. doi: 10.4028/

  16. 16.

    S.P. Midson: in Comprehensive Materials Processing, S. Hashimi, ed., Elsevier, Oxford, 2014, vol. 5, pp. 259–74. doi:10.1016/B978-0-08-096532-1.00517-3

  17. 17.

    [17] M. Tsuchiya, H. Ueno and I. Takagi: JSAE Rev., 2003, vol. 24, pp. 205–14. doi: 10.1016/S0389-4304(03)00013-4

  18. 18.

    [18] F. Pahlevani and M. Nili-Ahmadabadi: Int. J. Cast. Metal. Res., 2004, vol. 17, pp. 157–61. doi: 10.1179/136404604225020560

  19. 19.

    [19] M. Ramadan, M. Takita and H. Nomura: Mater. Sci. Eng. A, 2006, vol. 417, pp. 166–73. doi: 10.1016/j.msea.2005.10.054

  20. 20.

    [20] M. Ramadan, N. El-Bagoury, N. Fathy, M.A. Waly and A.A. Nofal: J. Mater. Sci., 2011, vol. 46, pp. 4013–19. doi: 10.1007/s10853-011-5329-7

  21. 21.

    [21] B. Abbasi-Khazaei and S. Ghaderi: J. Mater. Sci. Technol., 2012, vol. 28, pp. 946–50. doi: 10.1016/S1005-0302(12)60156-X

  22. 22.

    [22] J. Cui, H. Zhang, L. Chen, H. Li and W. Tong: Acta Metall. Sin., 2014, vol. 27, pp. 476–82. doi: 10.1007/s40195-014-0067-x

  23. 23.

    [23] A.S. Roca, H.D.C. Fals, J.A. Pedron and E.J. Zoqui: J. Mater. Process. Technol., 2012, vol. 212, pp. 1225–35. doi: 10.1016/j.jmatprotec.2012.01.012

  24. 24.

    [24] R.L. Nadal, A.S. Roca, H.D.C Fals and E.J. Zoqui: J. Mater. Process. Technol., 2015, vol. 226, pp. 146–56. doi: 10.1016/j.jmatprotec.2015.07.015

  25. 25.

    [25] A.M. Camacho, H.V. Atkinson, P. Kapranos and B.B. Argent: Acta Mater., 2003, vol. 51, pp. 2319–30. doi: 10.1016/S1359-6454(03)00040-5

  26. 26.

    ASTM A247-16a: Standard test method for evaluating the microstructure of graphite in iron castings, ASTM International, West Conshohocken, PA, 2016. Doi:10.1520/A0247-16A

  27. 27.

    ASTM E112-13: Standard test methods for determining average grain size, ASTM International, West Conshohocken, PA, 2013. doi:10.1520/E0112

  28. 28.

    [28] G.L Rivera, R.E. Boeri and J.A. Sikora: Scr. Mater., 2004, vol. 50, pp. 331–35. doi: 10.1016/j.scriptamat.2003.10.019

  29. 29.

    D.M. Stefanescu: in Properties and Selection: Irons, Steels and High Performance Alloys, ASM Handbook, ASM International, 1990, vol. 1, pp. 3–11. ISBN: 978-0-87170-377-4

  30. 30.

    [30] W. Xue and Y. Li: J. Alloy. Compd., 2016, vol. 689, pp. 408–15. doi: 10.1016/j.jallcom.2016.07.052

  31. 31.

    [31] K. Nakajima, M. Apel and I. Steinbach: Acta Mater., 2006, vol. 54, pp. 3665–72. doi: 10.1016/j.actamat.2006.03.050

  32. 32.

    [32] D. Liu, H.V. Atkinson and H. Jones: Acta Mater., 2005, vol. 53, pp. 3807–19. doi: 10.1016/j.actamat.2005.04.028

  33. 33.

    P.J. Uggowitzer and D.I. Uhlenhaut: in Thixoforming: Semi-solid Metal Processing, G. Hirt and R. Kopp, eds., Wiley-VCH, Weinheim, 2009, pp. 29–42. doi:10.1002/9783527623969.ch2

  34. 34.

    [34] C.A. Schneider, W.S. Rasband and K.W. Eliceiri: Nat. Methods, 2012, vol. 9, pp. 671–75. doi: 10.1038/nmeth.2089

  35. 35.

    [35] H. Wabusseg, G.C. Gullo, P.J. Uggowitzer, K. Steinhoff and H. Kaufmann: J. Mater. Sci., 2002, vol. 37, pp. 1173–78. doi: 10.1023/A:1014315421781

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This study was supported by São Paulo Research FoundationFAPESP under Grant Numbers 2011/19997-0 and 2015/06965-3. The authors would like to thank IMBIL Industry and Maintenance of Pumps ITA Ltda. for producing the cast iron and the Joining and Welding Research Institute, Osaka University, and the School of Mechanical Engineering, University of CampinasUNICAMP, for providing the necessary facilities.

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Correspondence to Eugenio José Zoqui.

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Manuscript submitted December 20, 2016.

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Benati, D.M., Ito, K., Kohama, K. et al. Study on the Microstructure and Liquid Phase Formation in a Semisolid Gray Cast Iron. Metall and Materi Trans B 48, 2293–2303 (2017).

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