1. 1) M.Kikuchi: J. Jpn. Weld. Soc., 72(2003)7, 12.
2. 2) M.Kikuchi: Spec. Steel, 49(2000)10, 10.
3. 3) Y.Tarutani, M.Miyahara, T.Hashizume, K.Higuchi and H.Fujikawa: Sumitomo Met., 45(1993)5, 92.
4. 4) K.Ito: Sokeizai, 49(2008)8, 16.
5. 6) M. Oku, S. Nakamura, N. Hiramatsu and Y. Uematsu: Nisshin Steel Tech. Rep., 66(1992), 37.