1. 1) H. K. D. H. Bhadeshia and Sir R. Honeycombe: Steels, 3rd ed., Elsevier, Butterworth-Heinemann, (2006).
2. 2) T. Takahashi, M. Nagumo and Y. Asano: J. Jpn. Inst. Met., 42 (1978), 708.
3. 3) T. Kimura, M. Takemasa and M. Honjo: JFE Tech. Rep., 26 (2010), 11.
4. 4) H. Yokoyama, S. Mitao and M. Takemasa: NKK Tech. Rep., (2002), No. 176, 59.
5. 5) Y. Kataoka, J. Furukawa, M. Ueda and T. Horita: 1992 Rail Steel Symp. Proc., Iron and Steel Society, Inc., USA, (1992), 11.