Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-22T05:22:19.518Z Has data issue: false hasContentIssue false

Heat- and fluid-flow phenomena in weld pools

Published online by Cambridge University Press:  20 April 2006

G. M. Oreper
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 USA
J. Szekely
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 USA

Abstract

A mathematical formulation is presented for the transient development of the fluid-flow field and the temperature field in a liquid pool, generated by a spatially variable heat flux falling on an initially solid metal block. This physical situation is an idealized representation of a TIG (tungsten-inert-gas) welding process. In the formulation allowance is made for electromagnetic, buoyancy and surface forces and the resultant equations are solved numerically.

It is found that both the convective flow field and the temperature field are markedly affected by the nature of the heat flux and the flux of electric current falling on the free surface.

In the absence of surface-tension effects a broadly distributed heat flux and corresponding current distribution cause a situation where both electromagnetic and buoyancy forces are important in determining the fluid-flow field; however, in these systems the fluid-flow field does not play a significant role in defining the heat-transfer process. In contrast, a sharply focused heat flux and current density on the free surface give rise to strong electromagnetically driven flows, which play an important role in determining the shape of the weld pool.

Calculations are also done exploring the effect of surface-tension-driven flows. It is found that surface-tension gradients may produce quite high surface velocities and can have a profound effect on determining the weld-pool shape.

Type
Research Article
Copyright
© 1984 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Atthey, D. R. 1980 J. Fluid Mech. 98, 787.
Bertram, L. A. & Zanner, F. J. 1981 In Modelling of Casting and Welding Processes (ed. M. D. Brady and D. Appelian).
Choudhary, M. & Szekely, J. 1980 Metallurg. Trans. 11B, 549.
Choudhary, M. & Szekely, J. 1981a Iron Making & Steelmaking 8, 225.
Choudhary, M. & Szekely, J. 1981b IMM 20, 1691.
Dilawari, A. H., Szekely, J. & Eagar, T. W. 1978 Metallurg. Trans. 9B, 371.
Gosman, H. D., Pun, W. M., Runchal, A. K., Spalding, D. B. & Wolfshtein, M. 1969 Heat and Mass Transfer in Recirculating Flows. Academic.
Gourlay, A. R. 1970 J. Inst. Maths Applics 6, 375.
Gourlay, A. R. & McGuire, G. R. 1971 J. Inst. Maths Applics 7, 216.
Heiple, C. R. & Roper, J. R. 1982 Welding J. 61, 97s.
Lancaster, J. F. 1980 Metallurgy of Welding, 3rd edn. Allen & Unwin.
Nestor, O. M. 1962 J. Appl. Phys. 33, 1638.
Ostrach, S. 1979 In (COSPAR) Space Research 19 (ed. M. Rycroft). Pergamon.
Sparrow, E. M., Patankar, S. V. & Ramadhyani, S. 1977 Trans. ASME C: J. Heat Transfer 99, 520.
Szekely, J. 1979 In Rate Processes of Extractive Metallurgy (ed. H. Y. Sohn & M. E. Wadsworth). Plenum.