Abstract
Two series of experiments have been conducted to determine the influence of rare earth additions on the nucleation and crystallization behavior of pure iron and 1045 steel. In the first series, additions of rare earth suicide or cerium dioxide powder to two-Kg 1045 steel ingots indicated that rare earth suicide can refine the as-cast structure of such ingots. However, if the holding time after rare earth silicide addition is over two minutes, the grain refinement decreases. With cerium dioxide additions, a relatively large columnar zone was obtained. In the second series, the effects of cerium metal or cerium dioxide powder additions on the degree of undercooling obtainable in pure iron and 1045 steel were examined by the lévitation melting method. Surface tension measurements of the levitated droplets were carried out at the same time to investigate the possible effects of surface tension variations on the nucleation and crystallization behavior of the metals. The experimental data show that rare earth inclusions can greatly reduce the degree of undercooling of iron and steel, and that a small amount of dissolved cerium can further reduce the degree of undercooling of levitated droplets. The structure and reaction products obtained with Fe-Ce levitated droplets were examined with both optical and scanning electron microscopy as well as X-ray diffraction analysis. The experimental results clearly indicated that cerium solute redistribution during solidification is the dominant factor in refining the as-cast structure. A nucleation and solidification model for the Fe-Ce levitated droplets has been developed, which can successfully explain the experimental results.
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References
P. E. Waudby:International Metals Reviews, 1978, vol. 2, pp. 74–98.
J.C.M. Farrar and R.E. Dolby:Sulfide Inclusions in Steel, ASM, Metals Park, OH, 1975, p. 252.
Y. Nuri, T. Ohashi, T. Hiromoto, and O. Kitamura:Trans. I.S.I.J., 1982, vol. 22, pp. 399–407.
Y. Nuri, T. Ohashi, T. Hiromoto, and O. Kitamura:Trans. I.S.I.J., 1982, vol. 22, pp. 408–16.
A. Vahed and D.A. R. Kay:Metall. Trans. B, 1976, vol. 7B, pp. 375–83.
W. K. Lu and A. McLean:Iron and Steelmaking, 1974, vol. 1(4), pp. 228–33.
W. K. Lu and A. McLean:Met. Mater., Oct. 1974, pp. 452-57.
Y. Dong and Q. Han:Acta Metallurgica Sinica, 1986, vol. 22, no. 2, pp. 149–55.
M. P. Braun and Y. Y. Skok:Russian Casting Production, 1966, vol. 98, pp. 417–19.
T. Ohashi, H. Fujii, Y. Nuri, and K. Asano:Trans. I.S.I.J., 1977, vol. 17, pp. 263–70.
H. Hu, X. Zhong, and H. Li:Acta Metallurgica Sinica, 1984, vol. 20, no. 4, pp. 247–55.
H. Soda, A. McLean, and W. A. Miller:Trans. Japan Inst. Metals, 1977, vol. 18. pp. 445–54.
J. Schade, A. McLean, and W.A. Miller:Proc. of the TMS-AIME Hume Rothery Symp. on Undercooled Alloy Phases, New Orleans, LA, March 2-6, 1986, pp. 233-48.
L. Rayleigh:Theory of Sound, MacMillan and Co., 1894, vol. 2, p. 371.
H. Li: M. A.Sc. Thesis, Departments of Metallurgy and Materials Science, University of Toronto, 1986.
Q. Han, Y. Dong, X. Feng, C. Xiang, and S. Yang:Metall. Trans. B, 1985, vol. 16B, pp. 785–92.
N. El-Kaddah and J. Szekely:Metall. Trans. B, 1983, vol. 14B, pp. 401–10.
W.A. Tiller, K. A. Jackson, J. W. Rutter, and B. Chalmers:Acta Metall, 1953, vol. 1, pp. 428–37.
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on research leave from Beijing University of Iron and Steel Technology
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Li, H., McLean, A., Rutter, J.W. et al. Influence of rare earth metals on the nucleation and solidification behavior of iron and 1045 steel. Metall Trans B 19, 383–395 (1988). https://doi.org/10.1007/BF02657736
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DOI: https://doi.org/10.1007/BF02657736