COMPUTER-SIMULATION OF SOLIDIFICATION IN COPPER BILLET CONTINUOUS-CASTING UNDER AN ASSUMPTION OF FLOW-FIELD

An algorithm has been developed for simulating the solidification in c opper billet continuous casting based on the direct finite difference method by assuming a flow field in the melt. The simulation model cons iders 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 obtaine d by adding molten Sn during casting. An experimentally determined rel ationship between DAS and cooling rate was used in the estimation of t he DAS distribution in the billet. The comparison between calculated a nd measured results showed a good agreement and it was found that negl ecting the heat transfer into the casting direction results in a maxim um error of 16.4%. It was also found that a more accurate estimation o f the thickness of the solidified layer and temperature near meniscus requires more accurate information on the velocity field.