The chemical homogeneity and metallurgical structure of vacuum arc remelted (VAR) zirconium ingots are directly responsible for product quality. It is therefore important to understand the relationship between these properties and the operating conditions. An in-depth analysis of the modelling of solidification phenomena during the VAR was carried out. Such model, solves a coupled set of transient equations for heat, momentum, solute transport and turbulence in an axisymmetric geometry. The remelting and cooling of a cylindrical ingot are calculated for time-dependent operating parameters. The solidification mechanisms implemented in the model can be applied to multi-component industrial alloys such as Zircaloy-4, which provides information on the macrosegregation phenomena studied in this paper. The model results were validated, based on the remelting of a specially designed chemically homogeneous Zircaloy-4 electrode. The results illustrate the importance of thermal and solute convection, the importance of the permeability of the partially solid material and the weak influence of nuclei density and solute diffusion in the solid phase on the prediction of macrosegregation in Zircaloy-4 ingots.

真空电弧重熔 (VAR) 锆锭的化学均匀性和冶金结构直接影响产品质量。因此，了解这些属性与操作条件之间的关系非常重要。对 VAR 期间的凝固现象建模进行了深入分析。这种模型求解了轴对称几何中热、动量、溶质输运和湍流的一组耦合瞬态方程。针对与时间相关的操作参数计算圆柱形锭的重熔和冷却。模型中实施的凝固机制可应用于多组分工业合金，例如 Zircaloy-4，它提供了有关本文研究的宏观偏析现象的信息。模型结果得到验证，基于特殊设计的化学均质 Zircaloy-4 电极的重熔。结果说明了热和溶质对流的重要性、部分固态材料的渗透性的重要性以及固相中的核密度和溶质扩散对预测 Zircaloy-4 铸锭宏观偏析的微弱影响。