The number of crystal nuclei is reduced when the eutectic crystallization of cast iron is melted in the induction melting furnace

In cupola smelting, the time from the melting of the charge to the outflow of molten iron from the furnace is very short, about 10 minutes. When smelting in an induction melting furnace, it takes at least 1 hour from the beginning of the charge to the tapping of iron, and it also has the unique stirring effect of induction heating, which greatly reduces the material in the molten iron that can be used as the foreign nucleus of graphite during eutectic crystallization. . For example, SiO2, which can be used as a foreign crystal nucleus, can easily react with the carbon in cast iron and disappear when the temperature is very high and there is a stirring effect:

SiO2＋O2→Si＋2CO↑

Therefore, when smelting gray cast iron in an induction melting furnace, special attention should be paid to the inoculation treatment. The amount of inoculant should be slightly more than that in the cupola smelting. It is best to perform a pre-incubation (pre-inoculation) in the furnace before being discharged. To improve the nucleation conditions of cast iron eutectic crystallization.