Simulation And Experiment Of Magnetic Permeability And Cooling Effect Analysis Of Two-section Mold With High Permeability

The soft-contact electromagnetic continuous casting technology of steel utilizes the electromagnetic pressure generated by the alternating electromagnetic field to deform the meniscus,widen the slag passage,improve the lubrication conditions and heat transfer conditions,and can remarkably improve the surface quality of the slab,which is very broad prospects for industrial application.However,the soft-contact continuous casting mold must meet the requirement of good magnetic permeability,high strength and good cooling effect.But the existing soft-contact mold can not meet the above requirements at the same time,failing to achieve industrial application now.The research group has developed a new type of high permeability copper alloy material in the earlier stage.The copper alloy and pure copper are connected by argon arc welding to form a high permeability two-section mold.In this paper,the study on the permeability and cooling effect of two-section mold are carried out to further verify the application prospects in the soft-contact continuous casting of steel.In this paper,aiming at the high permeability copper alloy mold developed by our research group,the permeability of copper alloy was studied by using the detection coil method to test the magnetic flux density distribution in the mold.As the object of study,the influence of different electromagnetic parameters and structural parameters on the magnetic flux density and electromagnetic force distribution in the mold was investigated by numerical calculation method.By examining the thickness of the shell at the outlet of the mold and the two-stage mold temperature distribution,the cooling effect of two-section mold was studied.The main research results are as follows.(1)The experimental results show that when the thickness of copper alloy mold is 10mm and the thickness of pure copper mold is 5mm,the maximum magnetic flux density in copper alloy mold is four times of the maximum magnetic flux density in pure copper mold.The magnetic flux density increases 36%when placing ingot in the mold.The magnetic flux density increases with the increase of the current intensity and decreases with the increase of the coil height.(2)The magnetic field distribution in the two-section mold is closely related to the parameters of current intensity,power frequency,coil position and liquid level.The numerical results show that the magnetic flux density increases with the current along the slope of 0.023mT/A.While increasing the frequency of the power supply,the magnetic flux density decreases almost linearly.Increase the coil position,magnetic flux density will increases.When the liquid level increases,the magnetic flux density increases.However,when the liquid level exceeds a certain value,further increasing the liquid level has almost no effect on the magnetic flux density.(3)For the two-section mold,the influence of current intensity,power frequency,coil position and liquid level on the distribution of electromagnetic force is further investigated.The results show that the electromagnetic force increases parabolic with the increase of current.Electromagnetic force increases with the parabolic linear frequency decreases,when the frequency is between 2500?3100Hz,a better soft contact effect can be obtained.Increase the coil position,the electromagnetic force increases,but increase significantly slower.Increase the liquid level,the electromagnetic force increases.When the liquid surface is located between the center of the coil and the top of the coil,the maximum value of the electromagnetic force is obtained.(4)The suitable parameters of the two-section mold used in SC-EMCC are obtained through numerical simulation.The coil current density is 2000A,the power frequency is 2500Hz,the top of the coil from the mold is 40 mm,the liquid level is 770mm.(5)The numerical calculation of the cooling effect of the two-section mold shows that the thickness of the shell at the outlet of the two-stage mold is 15.3mm,the maximum hot surface temperature of the mold is 529K,which is less than the recrystallize temperature of copper,and the maximum temperature of cold surface is 364K,less than the boiling temperature of cooling water.The results show that the two-section soft-contact mold could meet the cooling requirements for continuous casting.