Method for smelting high-carbon steel from semi-steel

Abstract

The invention provides a method for smelting high-carbon steel from semi-steel. The method adopts the semi-steel after extraction of vanadium as a raw material, and comprises the following steps of: adopting a low vanadium extraction process during smelting of a vanadium extraction converter to ensure that the carbon content of the semi-steel after the extraction of vanadium is not smaller than 3.70 weight percent, and the temperature of the semi-steel is not lower than 1,290 DEG C; adding active lime into the converter according to a standard of 10 to 15 kg in a ton of steel, adding high-magnesium lime into the converter according to a standard of 7 to 10 kg in a ton of steel, shaking the converter back and forth to ensure that the active lime and the high-magnesium lime are uniformly mixed with steel slag in the converter, then adding the semi-steel into the converter, and adding a ferro-silicon alloy into the converter, wherein the added amount of the ferro-silicon alloy can ensure that the initial alkalinity of furnace slag is 2 to 3; performing converting, and pouring out the furnace slag when the temperature of a molten pool is raised to be 1,400 to 1,500 DEG C; adding active lime into the converter according to a standard of 12 to 18 kg in a ton of steel and adding high-magnesium lime into the converter according to a standard of 9 to 12 kg in a ton of steel to perform secondary slagging; performing converting, and adding manganiferous iron ore into the converter to ensure that the alkalinity of the furnace slag is 4 to 5 and a CaO-SiO2-FeO-MnO low-melting-point slag system is formed; adding a cooling agent into the converter after converting for 3 to 5 minutes, and continuously converting until target molten steel and terminal furnace slag are obtained; and tapping. According to the method, dephophorization and carbon maintenance can be realized at the same time.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy, and more specifically, relates to a method for smelting high-carbon steel by using semi-steel after vanadium extraction. Background technique [0002] Usually, the method of converter smelting high carbon steel includes carburization method and high drawing supplementary blowing method. For the carburizing method, the tapping carbon is low, and a carburizing agent is added during the tapping process to carburize the molten steel. The carburizing method can ensure that the final molten steel has a low phosphorus content, but a large amount of carburizing agent needs to be added after tapping, so the composition of the molten steel fluctuates greatly. For the high-drawing supplementary blowing method, the carbon content of the tapped steel is relatively high, generally between 0.30wt% and 0.60wt%, the oxygen content in the molten steel is low, the alloy yield is high and stable, ...

AI Technical Summary

Problems solved by technology

However, for semi-steel steelmaking enterprises, due to the low carbon weight percentage in the semi-steel obtained after desulfurization and vanadium extraction (for example, 3.4wt% ~ 4.0wt%), the content of silicon and manganese exothermic slagging elements in the semi-steel They are all traces, and most of the slagging in semi-steel smelting is by adding acidic slagging materials.