Refractory plays an important role in the steel casting industry, and sleeve brick, as one of the important products, its performance and quality directly affect the smooth casting process and the quality of the final product. This paper will introduce the definition, function, characteristics, technical parameters and the importance in practical application of sleeve brick in detail.

I. Definition and structure of sleeve brick

Sleeve brick is a kind of hollow refractory tubular material, which is usually sheathed outside the metal mandrel. Its main function is to protect the metal core rod from direct erosion by high-temperature molten metal and slag, and at the same time maintain the rigidity of the metal core rod to control the direction and flow of casting flow. The structural design of sleeve brick makes it stable in extreme high temperature environment, ensuring the continuity and safety of casting process.

II. Function of sleeve brick

Protective metal mandrel: In the process of steel casting, the metal mandrel is in direct contact with high-temperature molten metal, which is easy to be corroded and damaged. As a protective layer, sleeve bricks can effectively isolate the corrosion of high-temperature molten metal and slag on metal mandrels, and prolong the service life of metal mandrels.

Control of casting flow: the internal channel of sleeve brick is designed reasonably, which can accurately control the flow direction and flow rate of molten metal and ensure the stability and uniformity of casting process. This is very important to improve the quality and production efficiency of castings.

Improve production efficiency: Because the sleeve brick can effectively protect the metal mandrel, it reduces the downtime and maintenance time caused by the damage of the metal mandrel, thus improving the efficiency of the whole casting production line.

III. Features of sleeve brick

High fire resistance: The main component of the sleeve brick is aluminum oxide (Al₂O₃), with a content of 40%-75%, which has extremely high fire resistance and can work stably in high temperature environment for a long time.

Good thermal shock resistance: In the casting process, the temperature changes sharply, so sleeve bricks need to have good thermal shock resistance to prevent cracking and damage caused by temperature changes.

Wear resistance and crack resistance: sleeve bricks will be washed and worn by molten metal during use, so they need to have good wear resistance and crack resistance to ensure their service life.

Corrosion resistance: In high temperature environment, the sleeve brick will come into contact with various chemicals, such as slag, so it needs to have good corrosion resistance to prevent it from being corroded by chemicals.

No pollution to molten metal: the sleeve brick will not release harmful substances and cause no pollution to molten metal during use, thus ensuring the quality of castings.

Accurate size: the sleeve brick has regular shape, accurate size and smooth channel, which can ensure the smooth flow of molten metal and reduce resistance.

IV. Technical parameters of sleeve brick

The technical parameters of sleeve brick include chemical composition, physical properties and size specifications. In terms of chemical composition, the content of main component alumina is between 40% and 75%, which can be adjusted according to different use requirements. In terms of physical properties, sleeve bricks have high fire resistance, good thermal shock resistance, wear resistance and crack resistance. In terms of size specifications, sleeve bricks can be customized according to the drawings provided by customers to meet the requirements of different casting processes.

V. Application of sleeve brick

Sleeve bricks are widely used in steel casting industry, especially in continuous casting process. It can effectively protect metal mandrel, control casting flow, improve production efficiency and ensure casting quality. With the continuous development of iron and steel industry, the demand for sleeve bricks is also increasing, and its application scope is also expanding.

VI. Conclusion

As an important refractory, sleeve brick plays an irreplaceable role in steel casting industry. Its excellent performance and wide application make it an indispensable part in the casting process. With the continuous progress of science and technology, the performance and quality of sleeve bricks will be continuously improved, which will provide more powerful support for the development of steel casting industry.