On the numerical prediction of coupled transfer and solidification process during vacuum consumable arc remelting of titanium alloys

A numerical model of the VAR process has been developed to optimize the remelting process of rich titanium alloys, which are highly prone to the formation of solidification defects related to the interdendritic liquid flow. The transient model describes the coupled transfer of heat, solutes and momentum, under turbulent flow conditions. It directly relates the operating parameters to the melt pool profile, to the hydrodynamic behavior in the melt and the mush zone and to the extent of segregation in the ingot. Simulations performed in both a pilot furnace and on an industrial scale, reveal the effect of stirring on the fluid flow and segregation phenomena. The model can be used to define the optimum melting conditions corresponding to the lowest risk of defect formation