摘要
In a continuous casting process,EMLS/EMLA(electromagnetic level stabilizer/accelerator)is applied effectively,which is able to control the surface stream velocity at meniscus in mold.The EMLS are applied to stabilize the molten steel flow and the meniscus fluctuation to prevent powder entrapments on high speed casters.Conversely,the EMLA are applied to activate the molten steel flow to promote heat transfer to the steel meniscus and keep proper temperature at meniscus in mold or wash inclusions off near the solidification front on low speed casters or at the beginning,the ending and during the ladle change of the casting for high speed casters.In this study,the effect of the EMLA on the molten steel flow is investigated.Numerical simulation of the electromagnetic field and the flow field were carried out.The EMLA applies a low frequency alternating magnetic field moving from SEN(submerged entry nozzle)to narrow slab faces below the nozzle exit ports.Simulation results indicate that,due to the electromagnetic force,the molten steel is forced to flow toward the magnetic field traveling direction in the region where the magnetic field is imposed.The molten steel flow is increased in proportion to the imposed accelerating electromagnetic force on the spouting stream from SEN.And excessive accelerating changes the double-roll pattern.However,the magnitude of the electromagnetic force is decided by the current intensity and frequency,a suitable imposed electric current can be chosen to increase the flow velocity properly and also reduce the amount of mold powder entrapments to a minimum.
In a continuous casting process,EMLS/EMLA(electromagnetic level stabilizer/accelerator)is applied effectively,which is able to control the surface stream velocity at meniscus in mold.The EMLS are applied to stabilize the molten steel flow and the meniscus fluctuation to prevent powder entrapments on high speed casters.Conversely,the EMLA are applied to activate the molten steel flow to promote heat transfer to the steel meniscus and keep proper temperature at meniscus in mold or wash inclusions off near the solidification front on low speed casters or at the beginning,the ending and during the ladle change of the casting for high speed casters.In this study,the effect of the EMLA on the molten steel flow is investigated.Numerical simulation of the electromagnetic field and the flow field were carried out.The EMLA applies a low frequency alternating magnetic field moving from SEN(submerged entry nozzle)to narrow slab faces below the nozzle exit ports.Simulation results indicate that,due to the electromagnetic force,the molten steel is forced to flow toward the magnetic field traveling direction in the region where the magnetic field is imposed.The molten steel flow is increased in proportion to the imposed accelerating electromagnetic force on the spouting stream from SEN.And excessive accelerating changes the double-roll pattern.However,the magnitude of the electromagnetic force is decided by the current intensity and frequency,a suitable imposed electric current can be chosen to increase the flow velocity properly and also reduce the amount of mold powder entrapments to a minimum.
