TTT Diagram of 10 pct CaO-90 pct Fe2O3 in Low-Temperature Region Below 1499 K


The important property of a sinter is its ability to withstand the load in a blast furnace (BF). During the cooling process, many compounds among CaO(C), FeO(W), and Fe2O3(F) precipitate, thereby affecting the quality of the sinter. In a previous study, the compounds that precipitated at a high quenching rate (7600 K/s) were clarified. In this study, a 10 pct CaO-90 pct Fe2O3 sample was melted and held at the desired temperatures from 1 minute to 168 hours using the hot thermocouple (HTC) method. The precipitated compounds were clarified by X-ray diffraction (XRD), while a time-temperature-transformation (TTT) diagram for the 10 pct CaO sample was determined below 1499 K. Unstable compounds (C2W4F9 and WFSS) were precipitated together with CF and F in the low-temperature region below 1428 K (1155 °C). However, the unstable compounds disappeared when the holding time was long. In the temperature region from 1428 K to 1499 K (1155 °C to 1226 °C), the rate of formation of CF2 was low; over a period longer than 168 hours, CF disappeared. Therefore, the reaction, CF + F = CF2, is very slow because the locations of CF and F are separated during precipitation from the melt.

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

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Fig. 19
Fig. 20
Fig. 21
Fig. 22
Fig. 23
Fig. 24
Fig. 25


  1. 1.

    Y. Kashiwaya: Metall. Mater. Trans. B, 2017, 48B, pp. 3228-3238, DOI:10.1007/s11663-017-1094-6

    CAS  Article  Google Scholar 

  2. 2.

    B. Phillips and A. Muan: J. Am. Ceram. Soc., 1958, vol. 41, pp. 445–54.

    CAS  Article  Google Scholar 

  3. 3.

    Y. Kashiwaya, C. E. Cicutti, and A. W. Cramb: ISIJ Int., 1998, vol. 38, pp. 357–65.

    CAS  Article  Google Scholar 

  4. 4.

    Y. Kashiwaya, C. E. Cicutti, A. W. Cramb, and K. Ishii: ISIJ Int., 1998, vol. 38, pp. 348–56.

    CAS  Article  Google Scholar 

  5. 5.

    Y. Kashiwaya, T. Nakauchi, P. Khanhson, S. Akiyama, and K. Ishii: ISIJ Int., 2007, vol. 47, pp. 44–52.

    CAS  Article  Google Scholar 

  6. 6.

    A. Semykina, J. Nakano, S. Seetharaman, V. Shatokha, and S. Seetharaman: Mater. Trans. B, 2010, 41B. pp. 940-45, DOI: 10.1007/s11663-010-9392-2.

    CAS  Article  Google Scholar 

  7. 7.

    K. Kojima, K. Nagano, T. Inazumi, K. Takagi, and K. Shinada: Tetsu-to-Hagane, 1969, vol. 55, pp. 669-81.

    CAS  Article  Google Scholar 

  8. 8.

    B. Bergman: J. Am. Ceram. Soc., 1986, vol. 69, pp. 608-11.

    CAS  Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Yoshiaki Kashiwaya.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Manuscript submitted March 11, 2019.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Kashiwaya, Y., Yanai, S. TTT Diagram of 10 pct CaO-90 pct Fe2O3 in Low-Temperature Region Below 1499 K. Metall Mater Trans B 50, 2095–2110 (2019).

Download citation