Modelling of Transport Phenomena in Laser Welding of Steels
Résumé
Laser Welded Blank solutions enable to reduce vehicles weight and to optimize their crash performances by means of simultaneous tuning of different grades and thicknesses. The present work aims to characterize numerically and experimentally materials mixing during laser welding. For better understanding of materials mixing based on convection-diffusion process in case of full penetrated laser welding, a 3D simulation of fluid flow, heat transfer and mass transfer has been performed to provide fusion zone shape and elements distribution map. The model has been developed basing on steady keyhole approximation and solved in quasi-stationary form in order to reduce computation time. Turbulent flow model was used to calculate velocity field. Fick law for diluted species was integrated to simulate the transport of alloying elements in the weld pool. In parallel, a number of experiments using pure Ni foils as tracers have been performed to obtain mapping of Ni distribution in the melted zone. SEM-EDX analysis of chemical composition has been made to map elements distribution in the melted zone. The results of simulation have been found in good agreement with experimental data.
Domaines
Physique [physics]Origine | Fichiers produits par l'(les) auteur(s) |
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