It is melted by 300KG medium frequency induction furnace, and is filled with ordinary scrap steel, ferrosilicon, ferromolybdenum and ferromanganese. The graphite is carbonized and the furnace charge is baked and slag-treated before being charged into the furnace to reduce the content of gas and inclusions in the molten steel.
In order to further improve the purity of the molten steel, the argon blowing process is adopted to install the ventilating brick at the bottom of the ladle, and the argon gas is blown through the ceramic ventilating steering molten steel, in addition to stirring the molten steel, the argon gas bubbles are small and dispersed, and have a degassing effect, thereby Reduce the amount of gases and inclusions. The process makes the alloy element and the deoxidation product have a uniform distribution, the degassing effect is good, the temperature is uniform, the occurrence of the ladle bottom phenomenon can be reduced, and the toughness of the high silicon cast steel can be improved.
In order to ensure the accuracy of the molten steel composition, the composition is measured by a fast spectrometer before the furnace is released. In the refining process, 0.1% silicon calcium is used as the deoxidizer, and the 0.2% aluminum block is finally deoxidized, and then the steel is discharged. When the molten steel is discharged (temperature is greater than 1600 degrees), the mixed rare earth containing cerium and lanthanum and vanadium titanium iron are broken to a particle size of less than 15 mm. The small pieces are placed in the lower part of the ladle after drying below 200 degrees, and the water is subjected to compound modification treatment by the in-package method. The austenitizing temperature of high silicon cast steel is 880~1080 degrees, the holding time is more than 2h, and then austempering is carried out in a salt bath furnace of 260~360 degrees. The isothermal holding time is 2~4h.