阅读说明：本技术 防堵塞浸入式水口 (Anti-blocking submerged nozzle ) 是由 姚金甫 舒友亮 杨光维 于 2020-04-17 设计创作，主要内容包括：本发明涉及一种防堵塞浸入式水口,包括本体、渣线段和内孔体,所述本体为Al-(2)O-(3)-C质材料,所述渣线段为ZrO-(2)-C质材料；所述内孔体为Al-(2)O-(3)-MgO-CaO质材料,其化学组分按重量百分比为：Al-(2)O-(3)：71～73%、MgO：19～26%、CaO：2～7%,其余为微量杂质,并外加有抗氧化剂和酚醛树脂结合剂；所述内孔体的原料包括尖晶石和二铝酸钙,其中二铝酸钙的重量百分比为8～30%；所述内孔体的厚度为5～8mm。本发明的内孔体材料兼顾了抗热震、抗冲刷和抗侵蚀性能,使得浸入式水口具备良好的防堵塞性能。(The invention relates to an anti-blocking submerged nozzle which comprises a body, a slag line segment and an inner hole body, wherein the body is made of Al 2 O 3 -a C material, the slag line segment being ZrO 2 -a material C; the inner hole body is Al 2 O 3 -MgO-CaO material, the chemical composition of which is as follows by weight percentage: al (Al) 2 O 3 : 71-73%, MgO: 19-26% of CaO: 2-7 percent of the total weight of the phenolic resin, and the balance of trace impurities, and an antioxidant and a phenolic resin bonding agent are additionally added; the raw materials of the inner pore body comprise spinel and calcium dialuminate, wherein the weight percentage of the calcium dialuminate is 8-30%; the thickness of the inner hole body is 5-8 mm. The inner hole body material has thermal shock resistance, erosion resistance and erosion resistance, so that the submerged nozzle has good anti-blocking performance.)

1. An anti-blocking immersion type water gap comprises a body, a slag line segment and an inner hole body, wherein the body is made of Al₂O₃-a C material, the slag line segment being ZrO₂-a material C;

the method is characterized in that: the inner hole body is Al₂O₃-MgO-CaO material, the chemical composition of which is as follows by weight percentage: al (Al)₂O₃: 71-73%, MgO: 19-26% of CaO: 2-7 percent of the total weight of the composition, trace impurities and oxidation resistanceAgent and phenolic resin binder.

2. The anti-clogging submerged entry nozzle of claim 1, wherein: the raw materials of the inner pore body comprise spinel and calcium dialuminate, wherein the weight percentage of the calcium dialuminate is 8-30%.

3. The anti-clogging submerged entry nozzle of claim 2, wherein: the spinel is sintered spinel or electric-melting spinel.

4. An anti-clogging submerged entry nozzle according to any one of claims 1 to 3, wherein: the thickness of the inner hole body is 5-8 mm.

Technical Field

The invention relates to the technical field of steelmaking continuous casting, in particular to an anti-blocking submerged nozzle.

Background

A submerged entry nozzle, which is a key functional refractory material in a continuous casting process, is installed between a tundish and a mold, and generally includes a body, a slag line section, and an inner bore body in which a passage for transferring molten steel from the tundish to the mold is provided. In continuous casting production, the interior pore body nodulation or jam often takes place when the casting aluminium killed steel, and the problem that slight jam can only be solved to increase slide or stopper stick aperture, if block up seriously then lead to unable continuation casting, directly influence continuous casting production in the same direction as moving. The inner hole body nodulation also brings a plurality of quality problems, for example, nodulation on the inner hole body can cause bias current and crystallizer liquid level fluctuation, peeled nodulation floats and stays in molten steel, and the like, so that surface and inner defects of casting blanks are generated, and defects such as 'black lines' of plates and flaw detection incompatibilities of sectional materials are generated. Therefore, how to avoid the clogging of the submerged nozzle has become one of the key links for improving the production efficiency of continuous casting.

The main body of the prior most submerged nozzle is Al₂O₃-C material with ZrO in the slag line segment₂The inner hole body which is in contact with the molten steel is made of Al₂O₃-SiO₂Material, Al₂O₃The components are 65-80 percent of SiO₂The component is 15-30%, can meet the requirements of erosion resistance and thermal shock resistance, but contains SiO₂The inner hole body of the component can react with molten steel in the continuous casting process, and the surface of the material is easy to form nodules, so that a water gap is blocked. Further, the foreign and endogenous inclusions in molten steel adhere to the inner wall of the inner bore, which is also a factor of clogging of the nozzle. Endogenic inclusions, e.g. Al as deoxidation product in steel making₂O₃Solid Al formed in aluminum killed steel or Al-Si killed steel and not completely floating and removing₂O₃Inclusions or containing Al₂O₃The high-melting-point composite inclusion is easy to adsorb, gather and grow on the inner wall under the action of molten steel turbulence, thereby causing the water gap to be blocked. The foreign inclusions are formed by the erosion of the refractory materials of the steel ladle and the tundish, and are not completely floated after entering the molten steel, for example, the inclusions of MgO or magnesia-alumina spinel formed by the erosion of the refractory materials containing MgO are easily attached to the inner wall of the inner hole body because of the high melting points of the inclusions.

Disclosure of Invention

The invention aims to provide an anti-clogging submerged nozzle, wherein an inner hole body of the submerged nozzle is made of a spinel material, and a proper amount of calcium dialuminate is added into the spinel material, so that the anti-clogging and anti-clogging performance of the submerged nozzle is effectively improved.

The invention is realized by the following steps:

prevent blockking up and soakThe formula mouth of a river, including body, sediment line section and hole body, the body is Al₂O₃-a C material, the slag line segment being ZrO₂-a material C;

the inner hole body is Al₂O₃-MgO-CaO material, the chemical composition of which is as follows by weight percentage: al (Al)₂O₃: 71-73%, MgO: 19-26% of CaO: 2-7 percent of the total weight of the phenolic resin, and the balance of trace impurities, and an antioxidant and a phenolic resin bonding agent are additionally added.

The raw materials of the inner pore body comprise spinel and calcium dialuminate, wherein the weight percentage of the calcium dialuminate is 8-30%.

The spinel is sintered spinel or electric-melting spinel.

The thickness of the inner hole body is 5-8 mm.

The raw material of the inner hole body adopts spinel (Al)₂O₃MgO) and calcium dialuminate (CaAl)₄O₇Abbreviated as CA₂) In combination, the stable characteristic of spinel at high temperature is utilized, and Al in molten steel cannot be mixed in the continuous casting process₂O₃The components react, the compact strength is high, and a compact surface is formed at the casting temperature, so that Al in molten steel is ensured₂O₃The impurities are not easy to adhere to the inner wall of the inner hole body, and the characteristics of low thermal expansion coefficient and high melting point of calcium dialuminate are utilized to improve the thermal shock resistance of the spinel, so that the obtained inner hole body is made of Al₂O₃The ternary system of-MgO-CaO has good thermal shock resistance and excellent anti-scouring performance, does not produce low-melting-point compounds, and can meet the performance requirements of anti-nodulation and anti-clogging.

Compared with the prior art, the invention has the following beneficial effects: the inner hole body material has thermal shock resistance, erosion resistance and erosion resistance, so that the submerged nozzle has good anti-nodulation and anti-clogging performances.

Detailed Description

The present invention will be further described with reference to the following specific examples.

An anti-blocking submerged nozzle comprises a body, a slag line segment and an inner hole body.The body is Al₂O₃-a C material, the slag line segment being ZrO₂And the-C material adopts an isostatic pressing process.

The inner hole body is Al₂O₃-MgO-CaO material, the chemical composition of which is as follows by weight percentage: al (Al)₂O₃: 71-73%, MgO: 19-26% of CaO: 2-7 percent of the total weight of the phenolic resin, and the balance of trace impurities, and an antioxidant and a phenolic resin bonding agent are additionally added.

The raw materials of the inner pore body comprise spinel and calcium dialuminate. The spinel may be sintered spinel or fused spinel, and is high-grade spinel, SiO₂The content of (A) is not more than 0.5%. The spinel material is stable at high temperature and will not react with Al and Al in molten steel during continuous casting₂O₃The components react, and the compactness and the high strength ensure that Al in molten steel₂O₃And the like, are not easily adhered. However, the thermal expansion coefficient of spinel is large, the thermal shock resistance is not enough, and the spinel material may crack or even peel off in use, so that the spinel (Al) is formed₂O₃-MgO) with calcium dialuminate (CaAl)₄O₇Abbreviated as CA₂) Calcium dialuminate is a compound of calcium aluminate series, and has high melting point (1765 + -25 deg.C) and very low thermal expansion coefficient (200 deg.C, 1.4 × 10)^-6/℃；1400℃，4.4×10^-6/° c), the combination of spinel and calcium dialuminate provides the inner pore body with good thermal shock resistance and excellent scour resistance. The weight percentage of the calcium dialuminate is 8-30%, if the weight percentage is lower than 8%, the effect of improving the thermal shock resistance of the inner hole body material is insufficient, and if the weight percentage exceeds 30%, although the thermal shock resistance of the inner hole body material is improved, the content of spinel is relatively low, and good anti-blocking performance cannot be guaranteed.

In the preparation process of the inner hole body, 8-30 wt% of calcium dialuminate is added into sintered spinel or electric-melting spinel, a small amount of antioxidant (such as metal Al, Si and the like) and phenolic resin bonding agent are added, the mixture is uniformly mixed and then is subjected to isostatic pressing, and the obtained inner hole body is Al₂O₃-MgO-CaO substanceThe material comprises the following chemical components in percentage by weight: al (Al)₂O₃: 71-73%, MgO: 19-26% of CaO: 2-7% and the thickness of the inner hole body is 5-8 mm.

Table 1 lists the specific weight percentages (wt%) of the raw material ratios and chemical components for examples 1-5, and the performance of each example, as shown below:

table 2 lists the specific weight percentages (wt%) of the raw materials and chemical components of comparative examples 6-9, and lists the performance of each comparative example, as follows:

as can be seen from table 1, the weight percentage of the calcium dialuminates of examples 1 to 5 is within a proper numerical range, and the performance indexes in various aspects are considered, so that the better anti-blocking performance can be provided during continuous casting, and the good thermal shock resistance, erosion resistance and corrosion resistance can be ensured. As can be seen from Table 2, comparative example 6 does not contain calcium dialuminate, has poor thermal shock resistance, and the material is easy to crack in use; the calcium dialuminate in the comparative example 7 has a low content, poor thermal shock resistance and is easy to crack; the calcium dialuminate in the comparative example 8 has higher content and good thermal shock resistance, but has poorer anti-blocking performance; in comparative example 9, the inner porous body was Al₂O₃-SiO₂The material has good thermal shock resistance but poor anti-blocking performance.

Table 3 specifically shows the comparison between the nozzle clogging of example 2 and comparative example 9 after five casting furnaces of bearing steel, as follows:

item	Example 2	Comparative example 9
			Nozzle nodulation layer thickness (mm)	3.5	9
Reduction ratio of nozzle clogging layer (%)	61	/

As can be seen from Table 3, example 2 contains the chemical component Al in an appropriate ratio₂O₃MgO and CaO have obvious effects of preventing nodulation and blocking, and the thickness of the nodulation layer of the water gap is reduced by 61 percent.

The inner hole body material of the anti-blocking submerged nozzle is added with the calcium dialuminate in a proper proportion on the basis of the spinel, so that the inner hole body is not easy to form a nodule in the continuous casting process, has good anti-blocking performance, and has good thermal shock resistance, scouring resistance and erosion resistance.

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.