Formation and Deformation Mechanism of Al2O3-CaS Inclusions in Ca-Treated Non-Oriented Electrical Steels


Industrial trials were performed to study the effect of calcium treatment on inclusions in non-oriented electrical steels. The evolution and characterization of inclusions in both molten steel and rolled steel were investigated, including a thermodynamic analysis using FactSage 7.1. In the Ca-treated steel, alumina inclusions were transformed into Al2O3-CaO-CaS, with a mass fraction of CaO that increased with increasing the Ca/S ratio. Inclusions of Al2O3-CaO-CaS were classified into wrapping and adhesion type according to their morphologies. Adhesion-type Al2O3-CaO-CaS inclusions were observed only in the steel with Ca/S > 0.84. The two types of Al2O3-CaO-CaS inclusions were transformed into Al2O3-CaS with distinctive morphologies. The mass fraction of Al2O3 and CaS in the inclusions was experimentally found to depend on the Ca/S ratio of the steel and confirmed by thermodynamic analysis. The two types of Al2O3-CaS inclusions could hardly be deformed during the hot-rolling process of the steel but showed different deformation behavior during the cold-rolling process of the steel. The component of CaS in the adhesion-type Al2O3-CaS inclusions was more easily separated from Al2O3 and formed a tail along the rolling direction of the steel, while only a little part of the CaS component broke off from the wrapping-type Al2O3-CaS inclusions.

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  1. 1.

    *LECO is a trademark of LECO Corporation, St. Joseph, MI.


  1. 1.

    1.H. Shimanaka, Y. Ito, K. Matsumara, and B. Fukuda: J. Magn. Magn. Mater., 1982, vol. 26, pp. 57–64.

    CAS  Article  Google Scholar 

  2. 2.

    2.L.J. Dijkstra and C. Wert: Phys. Rev., 1950, vol. 79, pp. 979–85.

    CAS  Article  Google Scholar 

  3. 3.

    3.P.A. Manohar, M. Ferry, and T. Chandra: ISIJ Int., 1998, vol. 38, pp. 913–24.

    CAS  Article  Google Scholar 

  4. 4.

    4.K. Matsumura and B. Fukuda: IEEE Trans. Magn., 1984, vol. 20, pp. 1533–38.

    Article  Google Scholar 

  5. 5.

    5.Q. Ren, L. Zhang, and W. Yang: Steel Res. Int., 2018, vol. 89, art. no. 1800047.

    Article  Google Scholar 

  6. 6.

    6.Y. Kurosaki, M. Shiozaki, K. Higashine, and M. Sumimoto: ISIJ Int., 1999, vol. 39, pp. 607–13.

    CAS  Article  Google Scholar 

  7. 7.

    7.F.J. Li, H.G. Li, Y. Wu, D. Zhao, B.W. Peng, H.F. Huang, S.B. Zheng, and J.L. You: J. Mater. Res., 2017, vol. 32, pp. 2307–14.

    CAS  Article  Google Scholar 

  8. 8.

    8.K. Jenkins and M. Lindenmo: J. Magn. Magn. Mater., 2008, vol. 320, pp. 2423–29.

    CAS  Article  Google Scholar 

  9. 9.

    9.H. Yashiki and T. Kaneko: ISIJ Int., 1990, vol. 30, pp. 325–30.

    Article  Google Scholar 

  10. 10.

    10.C.K. Hou: J. Magn. Magn. Mater., 2008, vol. 320, pp. 1115–22.

    CAS  Article  Google Scholar 

  11. 11.

    11.Y. Oda, Y. Tanaka, A. Chino, and K. Yamada: J. Magn. Magn. Mater., 2003, vols. 254–255, pp. 361–63.

    Article  Google Scholar 

  12. 12.

    12.T. Nakayama, N. Honjou, T. Minaga, and H. Yashiki: J. Magn. Magn. Mater., 2001, vol. 234, pp. 55–61.

    CAS  Article  Google Scholar 

  13. 13.

    13.W. Yang, L. Zhang, X. Wang, Y. Ren, X. Liu, and Q. Shan: ISIJ Int., 2013, vol. 53, pp. 1401–10.

    CAS  Article  Google Scholar 

  14. 14.

    14.Y. Liu, L.F. Zhang, Y. Zhang, H.J. Duan, Y. Ren, and W. Yang: Metall. Mater. Trans. B, 2018, vol. 49B, pp. 610–26.

    Article  Google Scholar 

  15. 15.

    15.L.F. Zhang, Y. Liu, Y. Zhang, W. Yang, and W. Chen: Metall. Mater. Trans. B, 2018, vol. 49B, pp. 1841–59.

    Article  Google Scholar 

  16. 16.

    16.L.E.K. Holappa and A.S. Helle: J. Mater. Process. Technol., 1995, vol. 53, pp. 177–86.

    Article  Google Scholar 

  17. 17.

    17.M. Lind and L. Holappa: Metall. Mater. Trans. B, 2010, vol. 41B, pp. 359–66.

    CAS  Article  Google Scholar 

  18. 18.

    18.Y. Tomita: J. Mater. Sci., 1994, vol. 29, pp. 2873–78.

    Article  Google Scholar 

  19. 19.

    19.F. Zhang, L. Miao, Z. Zong, B. Wang, Y. Zhang, and M.A. Zhigang: Baosteel Technol. Res., 2013, vol. 7, pp. 12–19.

    Google Scholar 

  20. 20.

    20.Y. Wan, S. Wu, and J. Li: Metall. Res. Technol., 2016, vol. 113, art. no. 101.

    Article  Google Scholar 

  21. 21.

    21.Y. Guo, K. Cai, Z. Luo, L. Liu, and Z. Liu: J. Univ. Sci. Technol. Beijing, 2005, vol. 27, pp. 427–30.

    CAS  Google Scholar 

  22. 22.

    22.N. Verma, P.C. Pistorius, R.J. Fruehan, M. Potter, M. Lind, and S.R. Story: Metall. Mater. Trans. B, 2011, vol. 42B, pp. 720–29.

    Article  Google Scholar 

  23. 23.

    23.Y. Ren, L. Zhang, and S. Li: ISIJ Int., 2014, vol. 54, pp. 2772–79.

    CAS  Article  Google Scholar 

  24. 24.

    24.J. Xu, F. Huang, and X. Wang: Metall. Mater. Trans. B, 2016, vol. 47B, pp. 1217–27.

    Article  Google Scholar 

  25. 25.

    Q. Ren, W. Yang, L. Cheng, Z. Hu, and L. Zhang: J. Magn. Magn. Mater. 2019, vol. 494, art. no. 165803.

    Article  Google Scholar 

  26. 26.

    26.Y. Chu, W. Li, Y. Ren, and L. Zhang: Metall. Mater. Trans. B, 2019, vol. 50B, pp. 2047–62.

    Article  Google Scholar 

  27. 27.

    27.G. Cheng, W. Li, X. Zhang, and L. Zhang: Metals, 2019, vol. 9, art. no. 642.

    CAS  Article  Google Scholar 

  28. 28.

    28.A. Segal and J.A. Charles: Met. Technol., 1977, vol. 4, pp. 177–82.

    Article  Google Scholar 

  29. 29.

    29.J. Guo, S.S. Cheng, Z.J. Cheng, and L. Xin: Steel Res. Int., 2013, vol. 84, pp. 545–53.

    CAS  Article  Google Scholar 

  30. 30.

    30.G. Xu, Z. Jiang, and Y. Li: Metall. Mater. Trans. B, 2016, vol. 47B, pp. 2411–20.

    Article  Google Scholar 

  31. 31.

    31.D. Zhao, H. Li, C. Bao, and J. Yang: ISIJ Int., 2015, vol. 55, pp. 2115–24.

    CAS  Article  Google Scholar 

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The authors are grateful for the support from the National Science Foundation China (Grant Nos. U1860206 and 51725402), Beijing International Center of Advanced and Intelligent Manufacturing of High Quality Steel Materials (ICSM), Beijing Key Laboratory of Green Recycling and Extraction of Metals (GREM), and High Quality Steel Consortium (HQSC), School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing (USTB), China.

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Correspondence to Wen Yang or Lifeng Zhang.

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Manuscript submitted June 8, 2019.

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Ren, Q., Yang, W., Cheng, L. et al. Formation and Deformation Mechanism of Al2O3-CaS Inclusions in Ca-Treated Non-Oriented Electrical Steels. Metall Mater Trans B 51, 200–212 (2020).

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