Secondary cooling technology for high-efficiency continuous billet-casting

The mathematical model of high-efficiency continuous billet casting was developed, incorporating the effective spraying water coefficient and the effective specific spraying water flowrate of secondary cooling. To realize uniform cooling in secondary cooling zones, the spraying cooling structure and the arrangement of nozzles were redesigned and optimized, and an additional spraying cooling zone was used. A new secondary cooling model of spraying water was built. It was found that the required spraying water flowrate of a cooling zone was related with the casting speed, the casting temperature, the compositions of liquid steel and the cooling water temperature of secondary cooling. The operation of the reformed caster proved that the spraying cooling structure and the new secondary cooling model were suitable, and the casting speed was greatly enhanced. The highest casting speed was （3.8 to 4.0） m/min for billet with a section of 150× 150 mm^2. The quality And the outout of the billet were imoroved, andthe economical benefit was heightened.

Dynamic Water Modeling and Application of Billet Continuous Casting

The continuous casting process is used for solidifying molten steel into semi-finished steel.The technology of secondary cooling is extremely important for output of the casting machine and billet quality.A dynamic water model was introduced,including solidification model in the secondary cooling,feedforward control strategy based on continuous temperature measurement in tundish,and feedback control strategy based on surface temperature measurement.The mathematical model of solidification process was developed according to the principle of solidification,and the solidification model was validated by measuring billet shell thickness through shooting nail and sulfur print.Primary water distribution was calculated by the solidification model according to procedure parameters,and it was adjusted by the other two control strategies online.The model was applied on some caster and billet quality was obviously improved,indicating that the dynamic water model is better than conventional ones.

Effect of M-EMS Parameters on Quality of 82B High Carbon Steel

In this paper,the rule of M-EMS on Φ250mm 82B high carbon steel during the casting process was investigated by numerical simulation and experiments.The influence of M-EMS current and frequency on distribution of flow field was researched.The simulation results show that:At the same current,velocity increases with the frequency increase.With the increase of frequency,the velocity first decreases and then increases as the frequency increase along the casting direction. At the same frequency,velocity increases with the current increase.The turbulence zone also become more strenuous, especially in free surface,the suitable turbulence is benefit to uniform steel temperature.Experiment results show that the quality defects of 82B high carbon steel can be significantly improved with M-EMS.The zone of central pipe decreases. With the increase of current,equiaxed zone ratio increases.Considered the results of numerical simulation and experiments, the optimized EMS parameters of Φ250mm high carbon steel are the stirring current of 480A and the stirring frequency of 3Hz,which can improve strand quality greatly.