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Artikel
The effect of surfactant redistribution on the weld pool shape during GTA-welding
| Författare: |
Winkler, C., Amberg, G.A., Inoue, H., Koseki, T, Fuji, M |
| Dokumenttyp: |
Artikel |
| Tillstånd: |
Publicerad |
| Tidskrift: |
Science and Technology of Welding and Joining |
| Volym: |
5
1-13 |
| År: |
1999 |
AbstractIn previous computations of GTA-welding on stainless steel plates the surfactant content in the workpiece is assumed to be in an equilibrium state. Moreover, we have found, that the surfactant concentration usually had to be adjusted in order to achieve agreement in the weld pool shapes of experiment and simulation. In this study a physicochemical approach for the redistribution of surfactant at the surface and in the bulk is presented for the first time in order to overcome the previous shortcomings. As representative surfactant sulfur is considered. The model allows surfactant molecular transport via convection, diffusion and sorption. It is shown that sulfur molecules accumulate at the surface at stagnation points, which affects the coefficient of surface tension and thus the final weld pool shape. Thus, the sulfur content in the simulation approaches to the nominal sulfur content in the steel plate. The theory is strengthened by both electron probe microanalysis and Auger electron spectroscopy.
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