A kind of smelting method of high-strength steel vanadium-nitrogen microalloying

Abstract

The invention discloses a high-strength steel smelting method capable of microalloying vanadium and nitrogen. The high-strength steel smelting method is characterized by comprising the following steps: A, smelting vanadium-titanium iron ore in a blast furnace; B, desulfurizing molten vanadium-titanium iron obtained in the step A; C, smelting the desulfurized molten vanadium-titanium iron in a converter; D, adding silicon carbide, carburant and vanadium-nitrogen alloys when the steel is discharged; F, continuously casting; and G, rolling the steel. The high-strength steel smelting method with the step parameter is a technique with combination of a low microalloying process and a steel surface cooling process; the residual vanadium in the molten vanadium-titanium iron is used, so that the consumption of the vanadium-nitrogen alloys is reduced; the cost is greatly reduced on the basis that the performance of the steel is ensured; the economic benefit is increased.

Description

technical field [0001] The invention relates to a method for smelting high-strength steel. Background technique [0002] At present, the production of ferroniobium (Nb) micro-alloying production is mainly used to manufacture high-strength seismic steel bars such as HRB500E and HRB400E. The production method of ferroniobium (Nb) microalloying has the following problems: The first pair of billets has high heating quality requirements: the effect of ferroniobium (Nb) microalloying can be fully manifested when the tapping temperature is above 1000 °C. Low cooling temperature of the second finished product: In the case of limited capacity of the rolling water system, in order to ensure the performance of the product, the rolling speed can only be reduced, resulting in low machine-hour output; it has a great impact on the 3# flying shear shear capacity of rolling steel. The third product has unstable performance: HRB500E Agt% is at the lower limit of the national standard, and HR...

AI Technical Summary

Problems solved by technology

The production method of ferroniobium (Nb) microalloying has the following problems: First, the quality of billet heating is high: the tapping temperature must be above 1000°C to fully reflect the effect of ferroniobium (Nb) microalloying

The cooling temperature of the second finished product is low: In the case of limited capacity of the steel rolling water system, the only way to ensure product performance is to reduce the rolling speed, resulting in low machine-hour output; it has a great impact on the shearing capacity of rolling steel 3# flying shear

The performance of the third product is unstable: HRB500E Agt% is at the lower limit of the national standard, and the yield strength of HRB400E (φ36, φ40) is low

Fourth, the cost of steelmaking and smelting is relatively high: ferroniobium (Nb) alloy is as high as 210,000 yuan per ton