阅读说明：本技术 一种适用于高钛钢的连铸保护渣 (Continuous casting mold flux suitable for high titanium steel ) 是由 刘志明 尚德礼 朱晓雷 彭春霖 魏崇一 杨骥 范思鹏 杨光 于 2021-09-14 设计创作，主要内容包括：本发明涉及一种适用于高钛钢的连铸保护渣,所述高钛钢的钛含量为0.5wt％～1.0wt％；所述连铸保护渣由以下质量百分比的组分组成：CaO 28％～32％,SiO-(2)10％～18％,MgO 2％～4％,TiO-(2)6％～12％,Al-(2)O-(3)16％～20％,B-(2)O-(3)+Na-(2)O+Li-(2)O 8％～10％,C 2％～4％,余量为不可避免的杂质。本发明所述连铸保护渣中添加TiO-(2),使得连铸保护渣中的钛与钢液中的钛形成动态平衡,添加含量较低的SiO-(2)并调节熔渣的酸碱性,添加B-(2)O-(3)用于提高润滑性,保证钢水连铸过程稳定进行；保护渣中不含氟元素,降低了对生态环境的危害。(The invention relates to continuous casting mold flux suitable for high titanium steel, wherein the titanium content of the high titanium steel is 0.5-1.0 wt%; the continuous casting mold flux consists of the following components in percentage by mass: CaO 28-32%, SiO 2 10％～18％，MgO 2％～4％，TiO 2 6％～12％，Al 2 O 3 16％～20％，B 2 O 3 +Na 2 O+Li 2 8 to 10 percent of O, 2 to 4 percent of C and the balance of inevitable impurities. TiO is added into the continuous casting mold flux 2 So that titanium in the continuous casting protective slag and titanium in the molten steel form dynamic balance, and SiO with lower addition content 2 Adjusting the acidity or alkalinity of the slag, adding B 2 O 3 The lubricating agent is used for improving the lubricating property and ensuring the stable operation of the molten steel continuous casting process; the protective slag does not contain fluorine, so that the harm to the ecological environment is reduced.)

1. The continuous casting mold flux is suitable for high titanium steel, and the titanium content of the high titanium steel is 0.5-1.0 wt%; the casting powder is characterized by comprising the following components in percentage by mass: CaO 28-32%, SiO₂ 10％～18％，MgO 2％～4％，TiO₂ 6％～12％，Al₂O₃ 16％～20％，B₂O₃+Na₂O+Li₂8 to 10 percent of O, 2 to 4 percent of C and the balance of inevitable impurities.

2. The continuous casting mold flux suitable for the high titanium steel according to claim 1, which is characterized by comprising the following components in percentage by mass: CaO 30%, SiO₂ 15％，MgO 4％，TiO₂ 12％，Al₂O₃ 18％，B₂O₃+Na₂O+Li₂O9%, C3%, and the balance unavoidable impurities.

3. The continuous casting mold flux suitable for high titanium steel according to claim 1, wherein said composition is CaO/SiO₂＝1.5～3.2。

4. The continuous casting mold flux suitable for high titanium steel according to claim 1, wherein the physical properties satisfy: the melting point is 970-1120 ℃, and the viscosity is 0.06-0.29 pas at 1300 ℃.

Technical Field

The invention relates to the technical field of metallurgy, in particular to continuous casting mold flux suitable for high titanium steel.

Background

The main functions of the continuous casting crystallizer casting powder include absorbing and dissolving non-metal inclusions in molten steel, lubricating between a crystallizer and a casting blank, improving heat transfer and the like. In the continuous casting process, if the titanium content in the molten steel is high, the molten steel is easy to chemically react with the covering slag, so that the performance of the covering slag is changed, and high-melting-point substances such as perovskite and the like are generated and mixed with the covering slag, so that the covering slag is easy to solidify on the surface of the liquid level of the crystallizer, and the problems of continuous casting bleed-out, slag inclusion, casting blank defects and the like are caused.

The chemical components of the conventional titanium-containing steel continuous casting covering slag mainly comprise CaO and SiO₂In order to improve the performance of the mold flux, Al is added into the mold flux₂O₃、B₂O₃、Na₂O、Li₂O, C, etc. When smelting high titanium steel, TiN is easily formed in molten steel, so that nozzle nodulation and blockage are caused; and TiO is added into the casting powder₂The reaction between the steel slag can be reduced to a great extent, and the smooth continuous casting process is ensured.

Patent No. CN105642849A discloses a casting powder for titanium-containing steel continuous casting, which has lower SiO2 content and higher Al2O3 content, and simultaneously, a certain amount of Mn2O3 is added as a strong oxidant, thereby effectively eliminating or relieving the harm of solid condensate on the steel slag interface in a crystallizer in the titanium-containing steel continuous casting process, and maintaining the stable performance of the casting powder. But the casting powder does not contain TiO2, so that the casting powder is not suitable for high titanium steel, and the casting powder has serious steel slag reaction and worsens the performance of the casting powder when smelting the high titanium steel.

Patent No. CN108127094A discloses a non-reactive covering slag for high titanium steel, which does not contain components such as SiO2, Na2O, B2O3 and the like, has low CaO content, and can effectively reduce the possibility that the covering slag absorbs TiO2 and is included to generate high-melting-point perovskite. However, since the mold flux does not substantially contain SiO2, the system of the mold flux is changed by controlling the melting temperature and the CaO content in order to reduce the basicity.

Patent No. CN11531140A discloses a high-titanium-oxide continuous casting mold flux for titanium-containing steel, wherein the mold flux contains 210-20% of TiO, so that the deterioration degree of the mold flux can be remarkably reduced, and the smooth continuous casting is ensured. However, the components of the fluorine-containing organic silicon material comprise (NaF + CaF2+ BaF2) 10-16%, and the fluorine content is high, so that the environment pollution is easily caused.

The patent No. CN110315039A discloses an application of fluorine-free covering slag in titanium-containing steel continuous casting, which solves the problem that slag rings or nozzle nodulation appears on the surface of molten steel in the titanium-containing steel continuous casting production process. But the slag does not contain TiO2, so that when high-titanium steel is smelted, the SiO2 content is high, the steel slag reacts seriously, continuous casting is not smooth, and the casting blank quality is poor.

Disclosure of Invention

The invention provides a continuous casting protective slag suitable for high titanium steel, which is added with TiO₂So that titanium in the continuous casting protective slag and titanium in the molten steel form dynamic balance, and SiO with lower addition content₂Adjusting the acidity or alkalinity of the slag, adding B₂O₃The lubricating agent is used for improving the lubricating property and ensuring the stable operation of the molten steel continuous casting process; the protective slag does not contain fluorine, so that the harm to the ecological environment is reduced.

In order to achieve the purpose, the invention adopts the following technical scheme:

the continuous casting mold flux is suitable for high titanium steel, and the titanium content of the high titanium steel is 0.5-1.0 wt%; the continuous casting mold flux consists of the following components in percentage by mass: CaO 28-32%, SiO₂ 10％～18％，MgO 2％～4％，TiO₂ 6％～12％，Al₂O₃ 16％～20％，B₂O₃+Na₂O+Li₂8 to 10 percent of O, 2 to 4 percent of C and the balance of inevitable impurities.

The continuous casting mold flux suitable for the high titanium steel comprises the following components in percentage by mass: CaO 30%, SiO₂15％，MgO 4％，TiO₂ 12％，Al₂O₃ 18％，B₂O₃+Na₂O+Li₂O9%, C3%, and the balance unavoidable impurities.

Among the components, CaO/SiO₂＝1.5～3.2。

The continuous casting mold flux is suitable for high titanium steel, and has the following physical properties: the melting point is 970-1120 ℃, and the viscosity is 0.06-0.29 pas at 1300 ℃.

Compared with the prior art, the invention has the beneficial effects that:

1) in the casting process of high titanium steel, because the titanium content in molten steel is high, a large amount of TiN can be separated out at the casting temperature and floats to a steel slag interface, and the TiN and SiO of the components in the casting powder₂When the slag is reacted, the components in the slag are reacted with [ Al ] in the molten steel]、[Ti]The reaction causes the alkalinity of the slag system to be increased, high-melting-point substances such as perovskite and the like are generated to be wrapped and mixed with the steel slag, solid coagulates are formed on the interface of the steel slag in the crystallizer, the performance of the casting powder is changed, and the problems of steel leakage, slag inclusion and other defects are easily caused. SiO in the casting powder₂Low content of TiO₂The casting powder has high content, and the casting powder can effectively inhibit steel slag reaction and prevent the casting blank quality problem caused by the performance deterioration of the casting powder in the continuous casting process when the casting powder is used for smelting the high-titanium steel;

2) the invention is on SiO₂Under the condition of low content, the lubricity is improved by adjusting the acidity and alkalinity of the slag, namely adding B into the covering slag₂O₃The study shows that B is added₂O₃The performance of the post-mold flux is improved;

3) the casting powder contains 18-28% of Al₂O₃With TiO in the mold flux₂And Li₂The components such as O and the like interact with each other, so that the lubricating and heat transfer effects between the casting blank and the crystallizer can be improved, the smooth running of the continuous casting process is ensured, and the quality of the casting blank is improved;

4) the casting powder disclosed by the invention does not contain fluorine, namely, the fluorine-free casting powder is developed, the problem of fluorine pollution is effectively solved, and the performance deterioration of the casting powder in the process of smelting high-titanium steel can be prevented.

Detailed Description

The invention relates to continuous casting mold flux applicable to high titanium steel, wherein the titanium content of the high titanium steel is 0.5-1.0 wt%; the continuous casting mold flux consists of the following components in percentage by mass: CaO 28-32%, SiO₂ 10％～18％，MgO 2％～4％，TiO₂ 6％～12％，Al₂O₃ 16％～20％，B₂O₃+Na₂O+Li₂8 to 10 percent of O, 2 to 4 percent of C and the balance of inevitable impurities.

The continuous casting mold flux suitable for the high titanium steel comprises the following components in percentage by mass: CaO 30%, SiO₂15％，MgO 4％，TiO₂ 12％，Al₂O₃ 18％，B₂O₃+Na₂O+Li₂O9%, C3%, and the balance unavoidable impurities.

Among the components, CaO/SiO₂＝1.5～3.2。

The continuous casting mold flux is suitable for high titanium steel, and has the following physical properties: the melting point is 970-1120 ℃, and the viscosity is 0.06-0.29 pas at 1300 ℃.

The following examples are carried out on the premise of the technical scheme of the invention, and detailed embodiments and specific operation processes are given, but the scope of the invention is not limited to the following examples. Any person skilled in the art should be able to substitute or change the technical solution of the present invention and its inventive concept within the technical scope of the present invention.

[ example 1 ]

In the embodiment, the titanium content of the smelted high-titanium steel grade is 1 wt%.

In the embodiment, the high titanium steel continuous casting mold flux consists of the following components in percentage by mass: CaO 30%, SiO₂14％，MgO 3％，TiO₂ 12％，Al₂O₃ 19％，B₂O₃+Na₂O+Li₂10% of O, 3% of C and the balance of inevitable impurities. Wherein, CaO/SiO₂＝2.14。

The melting point of the continuous casting mold flux is 998 ℃, and the viscosity is 0.15 pas at 1300 ℃.

When molten steel is poured, the continuous casting covering slag is added into a crystallizer. The liquid level fluctuation of the molten steel is kept within 3mm, the pulling speed is stabilized at 0.7m/min, the thickness of the slag layer is measured every 20min, the thickness of the slag layer is 8.5-10 mm, and the ideal design standard is achieved.

In the casting process, the continuous casting mold flux is uniformly spread on the surface of the molten steel. The continuous casting covering slag has the advantages of uniform and stable slagging, good air permeability, uniform flame distribution, no agglomeration and the like.

And observing the cold-state casting blank after cooling, wherein the surface of the casting blank has no transverse and longitudinal cracks, and the interior of the casting blank has no looseness and cracks.

[ example 2 ]

In the embodiment, the titanium content of the smelted high-titanium steel grade is 0.8 wt%.

In the embodiment, the high titanium steel continuous casting mold flux consists of the following components in percentage by mass: CaO 31%, SiO₂16％，MgO 2％，TiO₂ 10％，Al₂O₃ 20％，B₂O₃+Na₂O+Li₂O9%, C3%, and the balance unavoidable impurities. Wherein, CaO/SiO₂＝1.94。

The melting point of the continuous casting mold flux is 992 ℃, and the viscosity is 0.14 pas at 1300 ℃.

When molten steel is poured, the continuous casting covering slag is added into a crystallizer. The liquid level fluctuation of the molten steel is kept within 3mm, the pulling speed is stabilized at 0.7m/min, the thickness of the slag layer is measured every 20min, the thickness of the slag layer is 8.5-10 mm, and the ideal design standard is achieved.

In the casting process, the continuous casting mold flux is uniformly spread on the surface of the molten steel. The continuous casting covering slag has the advantages of uniform and stable slagging, good air permeability, uniform flame distribution, no agglomeration and the like.

And observing the cold-state casting blank after cooling, wherein the surface of the casting blank has no transverse and longitudinal cracks, and the interior of the casting blank has no looseness and cracks.

[ example 3 ]

In the embodiment, the titanium content of the smelted high-titanium steel grade is 0.7 wt%.

In the embodiment, the high titanium steel continuous casting mold flux consists of the following components in percentage by mass: CaO 29%, SiO₂15％，MgO 2％，TiO₂ 9％，Al₂O₃ 20％，B₂O₃+Na₂O+Li₂O10%, C3%, the balance being nothingAvoiding impurities. Wherein, CaO/SiO₂＝1.93。

The melting point of the continuous casting mold flux is 980 ℃, and the viscosity is 0.13 pas at 1300 ℃.

When molten steel is poured, the continuous casting covering slag is added into a crystallizer. The liquid level fluctuation of the molten steel is kept within 3mm, the pulling speed is stabilized at 0.7m/min, the thickness of the slag layer is measured every 20min, the thickness of the slag layer is 8.5-10 mm, and the ideal design standard is achieved.

In the casting process, the continuous casting mold flux is uniformly spread on the surface of the molten steel. The continuous casting covering slag has the advantages of uniform and stable slagging, good air permeability, uniform flame distribution, no agglomeration and the like.

And observing the cold-state casting blank after cooling, wherein the surface of the casting blank has no transverse and longitudinal cracks, and the interior of the casting blank has no looseness and cracks.

[ example 4 ]

In the embodiment, the titanium content of the smelted high-titanium steel grade is 0.9 wt%.

In the embodiment, the high titanium steel continuous casting mold flux consists of the following components in percentage by mass: CaO 29%, SiO₂13％，MgO 3％，TiO₂ 9％，Al₂O₃ 18％，B₂O₃+Na₂O+Li₂O9%, C4%, and the balance unavoidable impurities. Wherein, CaO/SiO₂＝2.23。

The melting point of the continuous casting mold flux was 1020 ℃ and the viscosity was 0.15 pas at 1300 ℃.

When molten steel is poured, the continuous casting covering slag is added into a crystallizer. The liquid level fluctuation of the molten steel is kept within 3mm, the pulling speed is stabilized at 0.7m/min, the thickness of the slag layer is measured every 20min, the thickness of the slag layer is 8.5-10 mm, and the ideal design standard is achieved.

In the casting process, the continuous casting mold flux is uniformly spread on the surface of the molten steel. The continuous casting covering slag has the advantages of uniform and stable slagging, good air permeability, uniform flame distribution, no agglomeration and the like.

And observing the cold-state casting blank after cooling, wherein the surface of the casting blank has no transverse and longitudinal cracks, and the interior of the casting blank has no looseness and cracks.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.