銅ビレット連続鋳造の速度場を仮定した凝固数値シミュレーション

抄録

An algorithm has been developed for simulating the solidification in copper billet continuous casting based on the direct finite difference method by assuming a flow field in the melt. The simulation model considers the temperature dependent thermo-physical properties, convection heat transfer due to the movement of liquid and solid phases, latent heat of solidification and heat transfer among carbon and copper molds, billet and cooling water. The simulation results were compared with a measured sump shape, cooling curves and dendrite-arm-spacing (DAS). The sump shape was estimated from the solidification structure obtained by adding molten Sn during casting. An experimentally determined relationship between DAS and cooling rate was used in the estimation of the DAS distribution in the billet. The comparison between calculated and measured results showed a good agreement and it was found that neglecting the heat transfer into the casting direction results in a maximum error of 16.4%. It was also found that a more accurate estimation of the thickness of the solidified layer and temperature near meniscus requires more accurate information on the velocity field.