Theoretical Study On Heat Transfer Behavior In Tinplate Slab Continuous Casting Mold

Aimed at the condition of tin plate blank which was produced by Hebei iron and Steel Group Tangshan Iron and Steel Group Limited liability company, starting from the three heat transfer process in the mold,three-dimensional transient heat transfer model, crystallizer copper plate three-dimensional steady state heat transfer model and the flux film two-dimensional heat transfer model were established, and the experimental simulation of the flux film vitrified behavior off occurred in the mold was conducted. The heat transfer of mold and solidification were analyzed by changing the process conditions, analyzing the effect of different technological conditions on the mold heat transfer and solidification, to explore the protective slag devitrification behavior rules, laying the foundation for the study of slag film devitrification behavior which had an effect on the thermal transfer in the mould.From the numerical simulation of heat transfer process in continuous cast slab concluded that the step size which was too large or too small would cause great impact on the simulation results, considering the accuracy of time needed for calculation and the calculation results, the 1s was chosen as the computation time of the model of the step. The billet thermal simulation results showed that, the surface temperature of the slab decreased gradually along the casting direction, shell along the casting direction thickened. Increasing the casting speed, superheat could make the slab surface temperature increased, at the same time would make the shell thickness thinning.The crystallizer copper plate heat transfer simulation results could be obtained: in the height direction of mold, at the meniscus and the coating near the junction temperature was higher, the recrystallization temperature but not more than copper. Because the coating effects and the bottom of the mould was not gradually effect of cooling water action, in mold coating area and from the bottom mould 30 mm has the phenomenon of back temperature. The temperature of bolt position was higher than the temperature at the location of the same thickness, which was caused by the large water joint spacing of bolt position and the weakness of the cooling effects than other position. Increasing the casting speed, the coating thickness and the wall thickness would make the mold hot surface temperature rise.The experimental simulation of flux film devitrification behavior showed that vitreous protective slag devitrification phenomenon occurred in the process of back temperature, the gun spar crystal was the main precipitation crystal; with the increase of the heating rate, the mold flux generated devitrification temperature rised. As the temperature increased, the crystallization of slag samples devitrification first increased and then decreased. With the thermostat setting temperature increasing, the incubation time of devitrification reduced; with the increase of slag vitreous membrane treatment temperature, flux film surface roughness and internal cavity increased. The flux film heat transfer simulation results showed: along the casting direction, the flux film temperature decreased gradually.