The Paton Welding Journal, 2010, №12



2010 №12 (09)

2010 №12 (02)

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TPWJ, 2010, #12, 2-5 pages
 
PECULIARITIES OF THERMAL AND HYDRODYNAMIC PROCESSES OCCURRING IN TIG AND A-TIG WELDING OF STAINLESS STEEL


Journal                    The Paton Welding Journal
Publisher                 International Association «Welding»
ISSN                       0957-798X (print)
Issue                       № 12, 2010 (December)
Pages                      2-5
 
 
Authors
D.V. KOVALENKO, I.V. KRIVTSUN, V.F. DEMCHENKO and I.V. KOVALENKO
E.O. Paton Electric Welding Institute, NASU, Kiev, Ukraine
 
 
Abstract
Analysis of distribution of temperature over the surface of the weld pool in TIG and A-TIG welding of stainless steel using the stationary and moving arc was carried out on the basis of calculation and experimental data. It is shown that in TIG and A-TIG welding the distribution of temperature over the weld pool surface above the boiling point has a characteristic plateau, the size of which is commensurable with size of the anode spot of the arc, the maximal temperature and size of this plateau being somewhat smaller in A-TIG welding. Problems of mathematical description and modelling of the Marangoni convection developing in A-TIG welding by the thermal-capillary and concentration-capillary mechanisms are discussed. Two circulation flows may form in the weld pool, their interaction causing a flow of the melt directed deep into the weld pool.
 
 
Keywords: TIG and A-TIG welding, stainless steel, stationary and moving arc, weld pool surface temperature, capillary Marangoni convection, force factors, penetration, experiment, mathematical modelling
 
 
Received:                ??.??.??
Published:               28.12.10
 
 
References
1. Paton, B.E., Yushchenko, K.A., Kovalenko, D.V. et al. (2006) Role of quasi-keyhole and Marangoni convection in formation of deep penetration in A-TIG welding of stainless steel (Phenomenological model of A-TIG welding of stainless steel). In: Proc. of Joint 16th Int. Conf. on Computer Technology in Welding and Manufacturing and 3rd Int. Conf. on Mathematical Modelling and Information Technologies in Welding and Related Processes (Kiev, Ukraine, June 2006). Kiev: PWI, 258-263.
2. Yushchenko, K.A., Kovalenko, D.V., Kovalenko. I.V. et al. (2007) Phenomenological model of existence and interaction of the system of activated arc and liquid channel of metal pool in A-TIG welding. IIW Doc. XII-212-1112-07.
3. Yushchenko, K.A., Kovalenko, D.V., Krivtsun, I.V. et al. (2008) Experimental studies and mathematical modelling of penetration in TIG and A-TIG stationary arc welding of stainless steel. IIW Doc. XII-212-1117-08.
4. Yushchenko, K.A., Kovalenko, D.V., Kovalenko, I.V. (2003) Investigation of peculiarities of A-TIG welding of stainless steels. IIW Doc. 212-1047-03.
5. Lancaster, J.F., Mills, K.C. (1991) Recommendations for the avoidance of variable penetration in gas tungsten arc welding. IIW Doc. 212-796-91.
6. Taimatsu, M., Nogi, K., Ogino, K.J. (1992) Surface tension of liquid Fe-O alloy. High Temp., Soc. Jap., 18(1), 14-19.

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