阅读说明：本技术 一种高硫钢水快速脱硫的lf精炼方法 (LF refining method for quickly desulfurizing high-sulfur molten steel ) 是由 姜静宇 赵国昌 刘德胜 郑京辉 李慧勇 付振坡 骈建峰 于 2019-09-30 设计创作，主要内容包括：本发明公开了一种高硫钢水快速脱硫的LF精炼方法,LF精炼前期加入电石1.2～1.5㎏/t钢、碳粉0～1㎏/t钢、萤石1.5～2.0㎏/t钢、硅铁0.5～2.0㎏/t钢、石灰7～8㎏/t钢扩散脱氧,造流动性好的CaO-SiO<Sub>2</Sub>-CaF<Sub>2</Sub>系炉渣；炉渣变白后将氩气调至1.2～1.5MPa强搅拌5～8min,然后喂铝线1.3～1.5㎏/t钢,将炉渣改性为吸附夹杂物较好的CaO-SiO<Sub>2</Sub>-Al<Sub>2</Sub>O<Sub>3</Sub>系炉渣；喂铝线后,待温度升至1600～1620℃,氩气调至0.8～1.2MPa,补加石灰2～3㎏/t钢搅拌1～5min。本发明LF精炼后钢液S≤0.005%,脱硫率95～98%；所得钢板中夹杂物≤2.0级。(The invention discloses an LF (ladle furnace) refining method for quickly desulfurizing high-sulfur molten steel, which comprises the steps of adding 1.2-1.5 kg of calcium carbide per ton of steel, 0-1 kg of carbon powder per ton of steel, 1.5-2.0 kg of fluorite per ton of steel, 0.5-2.0 kg of silicon iron per ton of steel, 7-8 kg of lime per ton of steel in a diffusion and deoxidation manner, and making good-fluidity CaO-SiO 2 ‑CaF 2 Slag is tied; after the slag is whitened, adjusting the argon gas to 1.2-1.5 MPa, strongly stirring for 5-8 min, feeding 1.3-1.5 kg of aluminum wires per t of steel, and modifying the slag into CaO-SiO with good impurity absorption 2 ‑Al 2 O 3 Slag is tied; after feeding the aluminum wires, after the temperature is raised to 1600-1620 ℃, argon is adjusted to 0.8-1.2MPa, and 2-3 kg of lime is added per t of steel and stirred for 1-5 min. According to the invention, the S content of molten steel after LF refining is less than or equal to 0.005%, and the desulfurization rate is 95-98%; the inclusion in the obtained steel plate is less than or equal to 2.0 grade.)

1. An LF refining method for quickly desulfurizing high-sulfur molten steel is characterized by comprising the following steps:

(1) 1.2-1.5 kg of calcium carbide per ton of steel, 0-1 kg of carbon powder per ton of steel, 1.5-2.0 kg of fluorite per ton of steel, 0.5-2.0 kg of ferrosilicon per ton of steel, and 7-8 kg of lime per ton of steel are added in the early stage of LF refining for diffusion and deoxidation, so that CaO-SiO2-CaF2 series slag with good fluidity is produced;

(2) after the slag is whitened, adjusting the argon gas to 1.2-1.5 MPa, strongly stirring for 5-8 min, feeding 1.3-1.5 kg of aluminum wires per t of steel, and modifying the slag into CaO-SiO2-Al2O3 series slag with good impurity absorption;

(3) after feeding an aluminum wire to molten steel, adjusting the temperature to be 1600-1620 ℃ and adjusting argon to be 0.8-1.2MPa, and adding 2-3 kg of lime per t of steel and stirring for 1-5 min.

2. The LF refining method for rapidly desulfurizing high-sulfur molten steel according to claim 1, wherein the desulfurization rate of the white slag in the step (2) is more than 50% by strong stirring.

3. The LF refining method for rapidly desulfurizing high-sulfur molten steel according to claim 1, wherein the LF refining method is applied to molten steel with a sulfur content of not less than 0.060% before LF refining.

4. The LF refining method for rapidly desulfurizing high-sulfur molten steel according to any one of claims 1 to 3, wherein the molten steel S after refining by the LF refining method is less than or equal to 0.005%, and the desulfurization rate is 95-98%.

5. The LF refining method for the rapid desulfurization of high-sulfur molten steel according to any one of claims 1 to 3, wherein inclusions in steel sheets produced from the molten steel after the refining by the LF refining method are controlled to be less than or equal to 2.0 level.

Technical Field

The invention belongs to the technical field of metallurgy, and particularly relates to an LF refining method for quickly desulfurizing high-sulfur molten steel.

Background

In the process of refining molten steel, desulfurization is one of the main refining tasks; the refining desulfurization rate is 90-95%; but when inferior scrap steel and sulfur-containing organic matters are used in electric furnace smelting and cannot be thoroughly separated, the sulfur content of the LF entering the station can reach more than 0.060 percent; at the moment, the LF smelting time and the aluminum consumption are increased during smelting, and secondary oxidation of molten steel is increased by stirring and desulfurizing the large argon after aluminum feeding, so that the production cost and the quality are adversely affected.

Sulfur is a harmful element in steel and has adverse effect on the service performance of products, so clean steel has strict requirements on sulfur in steel, the S is generally required to be less than 0.005%, and the S is required to be less than 0.002% in some cases, so the desulfurization efficiency is of great importance.

However, since the steel-making process is a more complex metallurgical process involving chemical, thermodynamic, kinetic, and other disciplines, the desulfurization process is more complex. At present, for the desulfurization smelting of high-sulfur steel with the LF arrival sulfur content of more than 0.060 percent, the desulfurization is carried out by using CaO-SiO2-CaF2 series slag, and then the desulfurization mode of adsorbing inclusions by using CaO-SiO2-Al2O3 series slag is not reported at present.

Disclosure of Invention

The invention aims to provide an LF refining method for quickly desulfurizing high-sulfur molten steel.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: an LF refining method for quickly desulfurizing high-sulfur molten steel comprises the following steps:

(1) 1.2-1.5 kg of calcium carbide per ton of steel, 0-1 kg of carbon powder per ton of steel, 1.5-2.0 kg of fluorite per ton of steel, 0.5-2.0 kg of ferrosilicon per ton of steel, and 7-8 kg of lime per ton of steel are added in the early stage of LF refining for diffusion and deoxidation, so that CaO-SiO2-CaF2 series slag with good fluidity is produced;

(2) after the slag is whitened, adjusting the argon gas to 1.2-1.5 MPa, strongly stirring for 5-8 min, feeding 1.3-1.5 kg of aluminum wires per t of steel, and modifying the slag into CaO-SiO2-Al2O3 series slag with good impurity absorption;

(3) after feeding an aluminum wire to molten steel, after the temperature is raised to 1600-1620 ℃, argon is adjusted to 0.8-1.2MPa, 2-3 kg of lime is added per t of steel, and stirring is carried out for 1-5 min, so that the aluminum loss and the secondary oxidation amount caused by strong argon stirring desulfurization are reduced.

In the step (2), the desulfurization rate of the white slag is over 50 percent through strong stirring.

The LF refining method is suitable for molten steel with the sulfur content of more than or equal to 0.060% before LF refining.

According to the LF refining method, the molten steel S is less than or equal to 0.005% after refining, and the desulfurization rate is 95-98%.

The inclusion in the steel plate produced by the molten steel refined by the LF refining method is controlled to be less than or equal to 2.0 grade.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in: 1. according to the invention, carbon powder, calcium carbide, ferrosilicon, fluorite and lime are added in the early stage of LF refining for diffusion deoxidation, CaO-SiO2-CaF2 series slag with good fluidity is produced, and the desulfurization rate is more than 50% after the slag is whitened by stirring through strong argon. 2. According to the invention, molten steel is fed with an aluminum wire after stirring and desulfurization by strong argon to modify the slag into CaO-SiO2-Al2O3 series slag with good impurity adsorption, the argon is adjusted to 0.8-1.2MPa after the temperature is raised to 1600-1620 ℃, and stirring is carried out for 1-5 min, so that the desulfurization effect is ensured, and the aluminum loss and secondary oxidation caused by stirring and desulfurization by strong argon are reduced. 3. The LF refining method is suitable for the molten steel with the sulfur content of more than or equal to 0.060 percent before LF refining. 4. According to the LF refining method, the molten steel S is less than or equal to 0.005% after refining, and the desulfurization rate is 95-98%. 5. The inclusion in the steel plate produced by the molten steel refined by the LF refining method is controlled to be less than or equal to 2.0 grade.

Detailed Description

The present invention will be described in further detail with reference to specific examples.