1. 1) S.Okushima, S.Kawasaki, Y.Suzuki and H.Matsuyama : Steelmaking Conf. Proc., Vol. 71, (1988), 145.
2. 2) K.Isobe, Y.Ishibashi, Y.Kawauchi, J.Tamura and N.Masumitsu : Steelmaking Conf. Proc., Vol. 71, (1988), 151.
3. 3) K.Isobe, Y.Kusano, M.Kobayashi, R.Kakimoto and E.Anzai : CAMP-ISIJ, 12 (1999), 153.
4. 4) T.Ito, T.Takahashi, S.Abeyama and A.Kimura : Influence of Metallugy of Machinability, ASM, (1975), 189.
5. 5) Y.Ohba, T.Kawamoto and S.Kitade : Sanyo Tech. Rep., 10 (2003), 19.