Effect of Welding Parameters on GTA Weld Shape for Pure Iron Plate under Ar-O2 Mixed Shielding

Abstract

Abstract: Weld shape variation for different welding parameters is investigated on pure iron plate under gas tungsten arc (GTA) welding with argon-oxygen mixed shielding. Results showed that small addition of oxygen to the argon base shielding gas can effectively adjust the oxygen adsorption to the molten pool. An inward Marangoni convection occurs on the pool surface when the oxygen content in the weld pool is over the critical value, 80×10-6, for pure iron plate under Ar-0.3%O2 mixed shielding. Low oxygen content in the weld pool changes the inward Marangoni to an outward direction under the Ar-0.1%O2 shielding. The GTA weld shape depends to a large extent on the pattern and strength of the Marangoni convection on the pool surface, which is determined by the content of surface active element, oxygen, in the weld pool and the welding parameters. The strength of the Marangoni convection on the liquid pool is a product of the temperature coefficient of the surface tension (dσ/dT) and the temperature gradient (dT/dr) on the pool surface. Different welding parameters will change the temperature distribution and gradient on the pool surface, and therefore, affect the strength of Marangoni convection and the weld shape.

Key words: Weld shape, Oxygen, Marangoni convection, Mixed shielding gas

Shanping LU, H.Fujii, K.Nogi. Effect of Welding Parameters on GTA Weld Shape for Pure Iron Plate under Ar-O2 Mixed Shielding[J]. J Mater Sci Technol, 2006, 22(03): 359-366.

References

[1] H.Lugwig: Weld. J., 1957, 36(Suppl), 1.
[2] B.E.Paton: Avtom. Svarka., 1974, (6), 1.
[3] W.S.Bennett and G.S.Mills: Weld. J., 1974, 53, 548s.
[4] W.F.Savage, E.P.Nippes and G.M.Goodwin: Weld. J., 1977, 56, 126s.
[5] C.R.Heiple and J.R.Roper: Weld J., 1981, 60, 143s.
[6] Y.Takeuch, R.Takagi and T.Shinoda: Weld J., 1992, 71, 283s.
[7] M.Tanaka, T.Shimizu, H.Terasaki, M.Ushio, F.Koshi- ishi and C.L.Yang: Sci. Tech. Weld. Join., 2000, 5, 397.
[8] P.J.Modenesi, E.R.Apolinario and I.M.Pereira: J. Mater. Process Tech., 2000, 99, 260.
[9] M.Kuo, Z.Sun and D.Pan: Sci. Tech. Weld. Join., 2001, 6, 17.
[10] D.Fan, Z.Sun, Y.Gu and M.Ushio: Trans. JWRI, 2001, 30, 35.
[11] D.S.Howse and W.Lucas: Sci. Tech. Weld. Join., 2000, 5, 189.
[12] C.R.Heiple and J.R.Roper: Weld. J., 1982, 61, 97s.
[13] P.C.J.Anderson and R.Wiktorowica: Weld Met. Fabr., 1996, 64, 108.
[14] W.Lucas and D.Howse: Weld Met. Fabr., 1996, 64, 11.
[15] D.D.Schwemmer, D.L.Olson and D.L.Williamson: Weld J., 1979, 58, 153s.
[16] Fengyao LIU, Sanbao LIN, Chunli YANG and Lin WU: Trans. China Weld Inst., 2002, 23(1), 1. (in Chinese)
[17] T.Paskell, C.Lundin and H.Castner: Weld J., 1997, 76, 57.
[18] Fengyao LIU, Sanbao LIN, Chunli YANG and Liu WU: Trans. China Weld Inst., 2002, 23(2), 5. (in Chinese)
[19] Y.Wang and H.L.Tsai: Metall. Mater. Trans., 2001, 32B, 501.
[20] S.M.Gurevich and V.N.Zamkov: Avtom Svarka, 1966, (12), 13.
[21] B.N.Bad'yanov, V.A.Davdov and V.A.Ivanov: Avtom Svarlca, 1974, (11), 1.
[22] B.N.Bad'yanov: Avtom Svarka, 1975, (1), 74.
[23] C.R.Heiple and P.Burgardt: WeJd J., 1985, 64, 159s.
[24] S.P.Lu, H.Fujii, H.Sugiyama, M.Tanaka and K.Nogi: ISIJ Int., 2003, 43, 1590.
[25] S.P.Lu, H.Fujii and K.Nogi: 4th Int. Conf. on High Temperature Capillarity, IIS, Sanremo, Italy, 2004, 43.
[26] S.P.Lu, H.Fujii, H.Sugiyama, M.Tanaka and K.Nogi: Mater. Trans., 2002, 43, 2926.
[27] S.Kou and Y.H.Wang: Weld J., 1986, 65, 63s.
[28] G.M.Oreper, T.W.Eagar and J.Szekely: Weld J., 1983, 62, 307s.
[29] M.Tanaka, H.Terasaki, M.Ushio and J.J.Lowke: Plasma Chemistry and Plasma Processing, 2003, 23, 585.
[30] M.Ushio, M.Tanaka and J.J.Lowke: IEEE Trans. Plasma Sci., 2004, 32, 108.
[31] Y.Z.Zhao, Y.P.Lei and Y.W.Shi: J. Mater. Sci. Tech- nol, 2005, 21, 408.
[32] W.Pitscheneder, T.Debroy, K.Mundra and R.Ebner: Weld. J., 1996, 75, 71s.
[33] T.Zacharia, S.A.David, J.M.Vitek and T.Debroy: Weld J., 1989, 68, 499s.
[34] T.Zacharia, S.A.David, J.M.Vitek and T.Debroy: Weld J., 1989, 68, 510s.
[35] P.Sahoo, T.Debroy and M.JMcnallan: Metall. Trans., 1988, 19B, 483.
[36] H.Taimatsu, K.Nogi and K.Ogino: J. High. Temp. Soc., 1992, 18, 14.
[37] T.A.Palmer and T.DerRoy: Weld. J., 1996, 75, 197s.
[38] Y.Sato, W.Dong, H.Kokawa and T.Kuwana: ISIJ Int., 2000, 40, S20.
[39] H.Kokawa: Trans. Jpn. Weld. Soc., 2003, 72, 414.
[40] H.Wada and R.D.Pehlke: Metall. Trans., 1977, 8B, 675.
[41] W.Dong, H.Kokawa, Y.Sato and S.Tsukamoto: Metall. Mater. Trans., 2003, 34B, 75.
[42] M.Uda, S.Ohno and T.Wada: Trans. Jpn. Weld. Soc., 1969, 38, 382.
[43] J.D.Katz and T.B.King: Metall Trans., 1989, 20B, 175.
[44] T.A.Palmer and T.DebRoy: Sci. Tech. Weld. Join., 1998, 3, 190.
[45] N.S.Tsai and T.W.Eagar: Metall. Trans., 1985, 16B, 841.
[46] P.Burgardt and C.R.Heiple: Weld. J., 1986, 65, 150s.