Abstract:In order to get a better understanding of the vacuum consumable arc remelting (VAR) processes and thus to optimize them, a 3D finite element model was developed for the temperature fields and heat transfer of titanium alloy ingots during VAR process. The results show that the temperature fields obtained by the simulation are well validated through the experiment results. The temperature distribution is different during the whole VAR process and the steady-state molten pool forms at 329 s for d100 mm × 180 mm ingots. At the initial stage of remelting, the heat dissipation of crucible bottom plays an important role in the whole heat dissipation system. At the middle of remelting, the crucible wall becomes a major heat dissipation way. The effect of cooling velocity on the solidification structure of ingots was investigated based on the temperature fields and the results can well explain the macrostructure of titanium alloy ingots.

Key words: vacuum arc remelting (VAR) process; titanium alloy ingot; macrostructure; temperature field; heat transfer