阅读说明：本技术 防结瘤中间包透气上水口 (Anti-caking tundish breathable water feeding port ) 是由 甘菲芳 高华 陈兆平 蒋晓放 徐国栋 梅峰 于 2020-03-30 设计创作，主要内容包括：本发明涉及一种防结瘤中间包透气上水口,包括碗部(1)、外层本体(2)、内层透气体(3)、直通孔(4)、气室狭缝(5)和进气吹氩管(6),外部氩气依次经进气吹氩管、气室狭缝和直通孔进入到所述上水口的内腔中；所述碗部和内层透气体为Al-2O-3-MgO-C质材料,其化学组分按重量百分比为：Al-2O-3：60～74%、MgO：18～32%、C：6～10%,其余为微量杂质；所述Al-2O-3-MgO-C质材料还外加有抗氧化剂和酚醛树脂结合剂。本发明能提供优良的抗热震性、抗侵蚀性、抗氧化性,综合性能优异,能改善上水口容易结瘤和堵塞的问题,且成本合理、质量稳定。(The invention relates to an anti-caking tundish breathable water feeding port which comprises a bowl part (1), an outer layer body (2), an inner layer breathable gas (3), a straight through hole (4), a gas chamber slit (5) and a gas inlet argon blowing pipe (6), wherein external argon sequentially enters an inner cavity of the water feeding port through the gas inlet argon blowing pipe, the gas chamber slit and the straight through hole; the gas permeable body of the bowl part and the inner layer is Al 2 O 3 -MgO-C material, which comprises the following chemical components in percentage by weight: al (Al) 2 O 3 : 60-74%, MgO: 18-32%, C: 6-10% and the balance of trace impurities; the Al is 2 O 3 the-MgO-C material is additionally provided with an antioxidant and a phenolic resin binder. The invention can provide excellent thermal shock resistance, erosion resistance and oxidation resistance, has excellent comprehensive performance, can improve the problems of easy nodulation and blockage of the water feeding port, and has reasonable cost and stable quality.)

1. An anti-caking tundish breathable water feeding port comprises a bowl part (1), an outer layer body (2), an inner layer breathable gas (3), a through hole (4), a gas chamber slit (5) and a gas inlet argon blowing pipe (6), wherein external argon enters an inner cavity of the water feeding port through the gas inlet argon blowing pipe (6), the gas chamber slit (5) and the through hole (4) in sequence;

the method is characterized in that: the bowl part (1) and the inner layer are permeable to gas (c)3) Is Al₂O₃-MgO-C material, which comprises the following chemical components in percentage by weight: al (Al)₂O₃: 60-74%, MgO: 18-32%, C: 6-10% and the balance of trace impurities; the Al is₂O₃the-MgO-C material is additionally provided with an antioxidant and a phenolic resin binder.

2. The anti-clogging tundish breathable upper nozzle according to claim 1, characterized in that: the chemical component Al₂O₃The raw material of the high-performance corundum is one or a combination of more of fused corundum, sintered corundum, alumina and magnesia-alumina spinel.

3. The anti-clogging tundish breathable upper nozzle according to claim 1, characterized in that: the raw material of the chemical component MgO is one or a combination of more of fused magnesia, sintered magnesia and magnesia-alumina spinel.

4. The anti-clogging tundish breathable upper nozzle according to claim 1, characterized in that: the raw material of the chemical component C is one or a combination of more of graphite, carbon black, asphalt and resin.

Technical Field

The invention relates to the technical field of steelmaking continuous casting, in particular to an anti-caking tundish breathable upper nozzle.

Background

The tundish is an important link in a continuous casting system, and is used for stabilizing the quality of molten steel after secondary treatment, promoting floating separation of impurities in the molten steel, homogenizing components and temperature, improving the quality of the molten steel and stabilizing casting operation. The tundish water feeding port is an important part in continuous casting production, and a water feeding port bowl part is matched with a stopper rod head to control the flow of molten steel so as to influence the liquid level of a tundish. However, in the continuous casting process, inclusions in molten steel often adhere to the inner wall and bowl of the upper nozzle, which causes the nodulation or blockage of the upper nozzle and seriously affects the quality of cast steel and casting blanks.

At present, inert gas-argon gas is blown into molten steel by a commonly adopted argon blowing breathable water feeding port, namely a tundish breathable water feeding port, formed argon bubbles can accelerate floating of impurities and form bubble films on the surface of an inner wall to prevent the impurities from adhering, so that the diameter reduction of an inner hole of the water feeding port is slowed down, and the castability of the molten steel is ensured. The ventilation mode includes a dispersion mode and a straight-through hole mode. The dispersive water feeding port is formed into a loose porous structure by using a material with higher porosity at the bowl part of the water feeding port, and has the defects of unstable air permeability, incapability of adjusting the air permeability in time according to production needs and the like. The through hole type tundish breathable water feeding port usually comprises a bowl portion, an outer layer body and an inner layer breathable gas, the inner layer breathable gas is an inner cavity of the water feeding port formed in a cavity structure, the inner cavity is communicated with the bowl portion to allow molten steel to flow through, a plurality of through holes are pre-buried in the wall of the inner layer breathable gas, and the through holes are communicated with an air inlet argon blowing pipe through a gas chamber slit arranged between the outer layer body and the inner layer breathable gas.

Therefore, the material of the air-permeable upper nozzle needs to have excellent air permeability (i.e. no clogging or clogging), thermal shock resistance and molten steel erosion resistance. At present, the breathable water feeding port of the tundish can be made of a plurality of materials, and mainly comprises Al of corundum mullite₂O₃-SiO₂Al of corundum of chromium₂O₃-Cr₂O₃Texture, Al₂O₃-C, Al₂O₃-ZrO₂-C, wherein corundum-mullite contains SiO₂The corundum and the chrome corundum contain Al, so that the thermal shock property is good, but the erosion resistance is poor, and the corundum and the chrome corundum are easy to form nodules and block after being melted and damaged₂O₃The alloy has good erosion resistance, high strength and scouring resistance, but has poor thermal shock resistance, is easy to crack and can cause nodulation on the inner wall. The permeable upper nozzle of the tundish can also be divided into two main categories of carbon-containing upper nozzle and carbon-free upper nozzle, the C content of the carbon-containing upper nozzle is generally at least 18 percent, the carbon content is high, the strength is lower, the scouring resistance and the oxidation resistance and the anti-caking performance are poor, and the carbon-free upper nozzle is generally Al₂O₃-SiO₂Material quality, Al₂O₃The components are 72-88 percent of SiO₂The component is 5-25%, which causes the defects of unstable air permeability and short service life, and Al is also adopted in the tundish water feeding port₂O₃-Cr₂O₃Material quality, Al₂O₃85-92% of components and Cr₂O₃The components are 2-8%, the molten steel scouring and erosion resistance is improved, the problem that the upper nozzle is quickly melted in the using process is solved, nodulation and blockage are easy to occur, and the argon blowing qualification rate of continuous casting production is influenced. With the change of the steel-making process conditions and the continuous casting furnace number, the existing water feeding port can not adapt to the requirements of the steel mill process and the change of the smelting steel varieties.

Disclosure of Invention

The invention aims to provide an anti-caking tundish breathable upper nozzle, wherein the inner layer of the upper nozzle is permeable to Al₂O₃The MgO-C material can effectively reduce the nodulation and the blockage of the water feeding port in a straight through hole ventilation mode.

The invention is realized by the following steps:

an anti-caking tundish breathable water feeding port comprises a bowl part, an outer layer body, an inner layer breathable gas, a straight-through hole, a gas chamber slit and a gas inlet argon blowing pipe, wherein external argon sequentially enters an inner cavity of the water feeding port through the gas inlet argon blowing pipe, the gas chamber slit and the straight-through hole;

the gas permeable body of the bowl part and the inner layer is Al₂O₃-MgO-C material, which comprises the following chemical components in percentage by weight: al (Al)₂O₃: 60-74%, MgO: 18-32%, C: 6-10% and the balance of trace impurities; the Al is₂O₃the-MgO-C material is additionally provided with an antioxidant and a phenolic resin binder.

The chemical component Al₂O₃The raw material of the high-performance corundum is one or a combination of more of fused corundum, sintered corundum, alumina and magnesia-alumina spinel.

The raw material of the chemical component MgO is one or a combination of more of fused magnesia, sintered magnesia and magnesia-alumina spinel.

The raw material of the chemical component C is one or a combination of more of graphite, carbon black, asphalt, resin and silicon carbide.

The invention adopts a through hole ventilation mode, and the upper nozzle bowl part and the inner layer ventilation body adopt Al₂O₃MgO-C material, consisting of corundum (Al)₂O₃) And aluminum magnesium spinel (Al)₂O₃predominantly-MgO) phase, magnesia-alumina spinel is not only excellent in corrosion resistance but also comparable to corundum (Al)₂O₃) The material has the advantages of providing better thermal shock resistance, ensuring that the erosion resistance, molten steel scouring resistance and thermal shock resistance of the material meet the use requirements by combining the two, simultaneously controlling the proper carbon (C) content, ensuring that the material is not easy to sinter in the use process, has better ventilation stability, is not easy to be infiltrated by molten steel and slag, has good thermal shock resistance, is not easy to crack or break, and ensures the strength and the oxidation resistance. Particularly, the corundum-spinel-low carbon material is also adopted at the bowl part of the water feeding port, so that the anti-nodulation and anti-blocking performance of the breathable water feeding port of the tundish can be obviously improved. The outer layer body of the upper nozzle adopts Al₂O₃the-C material can control lower cost, ensure stable quality and have excellent product cost performance. In addition, the upper water gap adopts a straight-through hole ventilation mode, the manufacturing is simple, the yield is high, the argon blowing flow is stable, the hysteresis is avoided, and the permeability and the stability of the argon blowing are effectively ensured.

Compared with the prior art, the invention has the following beneficial effects: the tundish breathable upper nozzle can provide excellent thermal shock resistance, erosion resistance and oxidation resistance, has excellent comprehensive performance, can solve the problem that the upper nozzle is easy to form lumps and block, and has reasonable cost and stable quality.

Drawings

FIG. 1 is a schematic structural view of an anti-clogging tundish breathable upper nozzle of the present invention;

in the figure, a bowl part 1, an outer layer body 2, an inner layer 3, a through hole 4, an air chamber slit 5 and an air inlet argon blowing pipe 6 are arranged.

Detailed Description

The invention is further described with reference to the following figures and specific examples.

Referring to fig. 1, the anti-caking tundish breathable water feeding port comprises a bowl part 1, an outer layer body 2, an inner layer breathable gas 3, a straight through hole 4, a gas chamber slit 5 and a gas inlet argon blowing pipe 6, wherein external argon sequentially enters an inner cavity of the water feeding port through the gas inlet argon blowing pipe 6, the gas chamber slit 5 and the straight through hole 4.

The bowl part 1 and the inner layer gas permeable body 3 are Al₂O₃-MgO-C material, which comprises the following chemical components in percentage by weight: al (Al)₂O₃: 60-74%, MgO: 18-32%, C: 6-10 percent, and the balance of trace impurities, wherein the composition phase is a corundum-spinel-carbon material, and the material is a low-carbon type functional refractory material. Wherein, Al₂O₃Melting point of 2050 ℃, MgO melting point of 2800 ℃, MgO-Al₂O₃The melting point of the magnesium aluminate spinel is 2135 ℃, the corundum and aluminum aluminate spinel phases are taken as main phases, and the excellent erosion resistance and molten steel scouring resistance can be ensured. Meanwhile, the carbon-containing material is not easy to sinter in the using process, has good air permeability stability, is not easy to be infiltrated by molten steel and slag, can meet the anti-caking requirement, also has good thermal shock resistance, is not easy to crack or fracture, but if the carbon content is too high, the material strength is reduced, the material is not resistant to corrosion and has poor oxidation resistance, so that Al₂O₃The carbon content of the-MgO-C material is controlled to be 6-10%, and a better performance balance point can be achieved.

The Al is₂O₃Chemical component Al in-MgO-C material₂O₃One or more combinations of refractory materials such as fused corundum, sintered corundum, alumina, magnesia-alumina spinel and the like can be selected as chemical component MgO, one or more combinations of refractory materials such as fused magnesia, sintered magnesia and magnesia-alumina spinel and the like can be selected as chemical component C, one or more combinations of carbon-containing raw materials such as graphite, carbon black, asphalt, resin and the like can be selected as chemical component C according to the weight percentage (Al) of the chemical components₂O₃: 60-74%, MgO: 18-32%, C: 6-10%) and adding antioxidant (such as B)₄C. One or two of Al and Mg) and phenolic resin binder, and putting the mixture into a forming die after uniformly mixing the ingredients, and integrally and carrying out one-time isostatic pressing.

The outer layer body 2 is Al₂O_3-The C material can keep lower cost and stable quality and provide better product cost performance.

Table 1 lists the specific weight percent (wt%) of the chemical components of examples 1-5 and comparative examples 6-9, as compared to the chemical components and performance of the examples, as follows:

as can be seen from Table 1, the chemical compositions of examples 1-5 have the following weight percentage ranges: al (Al)₂O₃: 60-74%, MgO: 18-32%, C: 6-10%, mainly by corundum and aluminum magnesium spinel phases, can provide excellent erosion resistance and molten steel scouring resistance, and simultaneously, the appropriate carbon content can ensure the anti-nodulation, thermal shock resistance and oxidation resistance of the material, so that the overall performance of the whole material is excellent due to the proportion of the chemical components, and the problems of nodulation prevention and blockage prevention of the breathable water feeding port of the tundish can be solved. Examples 1 to 5 contained only a trace amount of SiO introduced from the raw material₂Impurities. In addition, the antioxidant and the phenolic resin combined binder are raw material additives and are not in the calculated range of the weight percentage of the chemical components.

Comparative example 6 is Al₂O₃-SiO₂Aluminum carbonaceous material of-C, SiO₂The content is higher, resulting in poor erosion resistance. Comparative example 7 is Al₂O₃-ZrO₂the-C aluminum-zirconium carbon material has improved erosion resistance, but has high carbon content, so that the oxidation resistance and the strength are not high, the service life of the material is shortened, and the anti-nodulation and anti-clogging effects are not facilitated. Comparative example 8 is a commonly used Al₂O₃-SiO₂Of corundum-mullite material, SiO₂The content is high, the sintering is easy in the using process, the air permeability is reduced, and the phenomena of nodulation and blockage are frequently caused. Comparative example 9 is Al₂O₃-Cr₂O₃The chromium corundum carbon-free material has good erosion resistance, but poor thermal shock performance, and is easy to crack in use, so that argon blowing and air leakage are caused.

The bowl part and the inner layer air permeable body of the anti-caking tundish air permeable upper nozzle adopt Al₂O₃The MgO-C material ensures that the upper nozzle has better erosion resistance and scouring resistance, is not easy to form nodules and has long service life, and is combined with a ventilation mode of arranging a straight through hole in the inner layer ventilation gas, bubbles and bubble films formed by blowing argon can prevent the upper nozzle from forming nodules or blocking, and impurities in molten steel float upwards along with argon bubbles so as to clean the molten steel, thereby not only prolonging the service life of the upper nozzle, but also ensuring the number of continuous casting furnaces and the qualification rate of argon blowing.

The present invention is not limited to the above embodiments, and any modifications, equivalent replacements, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.