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The Ca-Fe phase diagram in [Massalski2] was redrawn from [1992Kah]. The Ca-Fe phase diagram near the Fe corner was reported by [1993Gla] partly based on [1960Kre] for the solubility of Ca in liquid Fe, as reviewed by [1994Oka]. This phase diagram is shown in Fig. 1. Formation of a γ loop was concluded in this study.
Solid lines in Fig. 2 show the Ca-Fe phase diagram reported by [1987Sch]. The Ca corner of this phase diagram is enlarged in Fig. 3. The (γFe) phase was not shown in the diagram of [1987Sch]. This can be explained by assuming that the γ loop is so narrow that it is located within the line width of the pure Fe line. This is quantitatively consistent with the diagram of [1993Gla] (Fig. 1). However, the quantitative scale of Fig. 1 is questionable, as discussed below. Figure 4 shows the Fe corner of the Ca-Fe phase diagram calculated by [1994Ang]. The L1 + L2/L2 boundary was calculated based on the data of [1964Spo] and [1985Koh]. When Fig. 1 and 4 are compared, it is found that discrepancy in the solubility of Ca in liquid Fe is about 100 times. It is more reasonable to assume that the scale in Fig. 1 is questionable because the six 9 purity in the horizontal axis is very uncommon.
The (γFe) phase was missing in the diagram of [1987Sch], as described above. However, the van’t Hoff relationship demands certain initial angle for the (αFe)/(αFe) + (γFe) boundary away from the 100% Fe line at both highest and lowest temperature limits (1394 and 912 °C). Because the L1 + (αFe)/(αFe) boundary is located very close to the 100% Fe line, the γ loop must cross this boundary. The temperatures at the crossing should not be much different from the allotropic transformation temperatures of γFe. Two dashed lines have been added in Fig. 2 to reflect this situation. After all, the overall Ca-Fe phase diagram looks like the one proposed by [1992Kah], but the behavior of the (γFe) phase must be clarified (tends to form a γ loop or not).
Ca-Fe crystal structure data are given in Table 1.
References
N.S. Kreshchanovskii, On the Partition of Calcium in Cast Steel, Liteinoe Proizvod., 1960, (8), p 31; quoted in [1993Gla]
D.L. Sponseller and R.A. Flinn, The Solubility of Calcium in Liquid Iron and Third-Element Interaction Effects, Trans. Metall. Soc. AIME, 1964, 230, p 876-888
M. Köhler, H.J. Engell, and D. Janke, Solubility of Calcium in Fe-Ca-Xj Melts, Steel Res., 1985, 56(8), p 419-423
E. Schürmann and H. Jacke, Melting Equilibria in the System Fe-C-Ca, Steel Res., 1987, 58(9), p 399-405, in German
D.J. Kahan and L.J. Swartzedruber, Ca-Fe (Calcium-Iron), Phase Diagrams of Binary Iron Alloys, H. Okamoto, Ed., ASM International, Materials Park, OH, 1992, p 84-86
V.N. Gladkii and N.T. Shevelev, New Data on the Fe-Ca Phase Diagram, Izv. Ross. Akad. Nauk, Metally, 1993, (6), p 207-209, in Russian, TR: Russ. Metall., 1993, (6), p 113-115
J.C. Anglezio, C. Servant, and I. Ansara, Contribution to the Experimental and Thermodynamic Assessment of the Al-Ca-Fe-Si System—I. Al-Ca-Si, Al-Fe-Si, and Ca-Fe-Si Systems. Calphad, 1994, 18(3), p 273-309
H. Okamoto, Comment on Ca-Fe (Calcium-Iron), J. Phase Equilib., 1994, 15(5), p 565-566
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Okamoto, H. Ca-Fe (Calcium-Iron). J. Phase Equilib. Diffus. 31, 88–90 (2010). https://doi.org/10.1007/s11669-009-9633-8
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DOI: https://doi.org/10.1007/s11669-009-9633-8