Transient VAR ingot growth modelling: application to specialty steels

A numerical model of the VAR process has been developed at the Ecole des Mines de Nancy over more than 12 years, in close collaboration with industrial partners, to simulate remelting of titanium and zirconium alloys. Nowadays, its applications are extended to specialty steels. Recent studies on the flow modelling highlighted the influence of the turbulence model and the mesh size on the computed evolution of the pool geometry in the upper part of the remelted ingot. Thus, various improvements have been achieved, resulting in a better modelling of the transport phenomena. In particular, a numerical model to simulate the continuous supply of metal in the crucible based on mesh cell splitting and growth has been developed and implemented in the software. The results obtained from the improved version are compared with experimental data from the observation of ingots remelted by Aubert & Duval. The relationship between electromagnetic stirring and the generation of turbulence is investigated from the model results.