| Molten metal solidifies in free surface state during electromagnetic casting (EMC) process. EMC is real non-mold foundry which improves surface quality of ingot greatly. But the continuously newborn oxide film in the surface of liquid column is damaged by the electromagnetic stirring in EMC and the pouring-in liquid metal, which results in the generation of inclusion in the inner and surface of ingots. And air content of ingots increases too. In this paper, the thought of hot-top EMC is used in aluminum slab EMC, and a lot of experimental and simulant researches are proceeded, based on which, some results with guiding meaning have been obtained.A whole set of hot-top EMC devices of aluminum slab and some types of screen structures were designed. The distribution of magnetic field under correlated conditions was measured. And the distribution rule of it was researched, based on which, the needed power supply and the position of freezing interface were determined.It is indicated by experimental result that, compared with integral screen, split screen can not only depresses magnetic field in the top of liquid column, which ensures the stabilization of liquid column, but also does not weaken magnetic field in the region of liquid-solid boundary obviously, which is favorable for meeting the half-suspending condition of molding.The rational technique parameters such as the position of the freezing interface, pouring temperature, cooling water strength and the height of liquid column were obtained by lots of experiments. Ingots with smooth surface were gained. It is found that the inclusion is retained in the top of ingot, and it is prevented of entering the inner and surface of ingots, which means that hot-top eliminates inclusion flaw of ingot efficiently.Air content test of test samples founded by hot-top EMC, DC, EMC and electromagnetic continuous casting are analyzed. It is found that air content of the first one is lower than others', which proves that hot-top does strengthen system stability and has the effect of removing inclusion.Experimental researches on hot-top electromagnetic continuous casting of Al round ingots are made. Rational technological parameters are confirmed, and Al round ingots whose surface quality is better than which of electromagnetic continuous casting ingots are casted.In this paper the calculation of numerical simulation for the magnetic field of hot-top EMC system was set up by using software of finite element software. |
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