In the process of steel casting, plug brick is one of the indispensable refractory materials, which plays a vital role in controlling molten steel flow and ensuring casting quality. This paper will introduce the characteristics, functions, production process and its importance in iron and steel industry in detail.

I. Characteristics of plug bricks

Plug brick is a kind of refractory used in steel casting, and its main component is alumina (AL₂O₃), the content of which is between 40% and 75%. This material has the following remarkable characteristics:

High fire resistance: the plug brick can remain stable in high temperature environment and will not be eroded by high temperature molten steel, ensuring the smooth casting process.

Good thermal shock resistance: during the casting process, the plug brick will frequently contact and leave the high-temperature molten steel, and its good thermal shock resistance enables it to withstand this temperature change and prolong its service life.

Excellent wear resistance and crack resistance: under the impact of molten steel, the wear resistance and crack resistance of plug brick can prevent its surface from wearing and cracking, and ensure its shape and size stability.

Good corrosion resistance: the plug brick will not be corroded by chemical components in molten steel and slag, thus avoiding pollution to molten steel.

Accurate size and shape: the plug brick has regular shape, accurate size and smooth surface, which can be closely matched with the nozzle brick to ensure the smooth and stable flow of molten steel.

II. Functions of plug bricks

The main function of plug brick is to control the flow of molten steel. In the process of steel casting, the plug brick is installed at the bottom of the plug rod and closely cooperates with the nozzle brick. When it is necessary to stop the flow of molten steel, the plug brick will contact with the nozzle brick to form a seal to prevent the leakage of molten steel; When it is necessary to resume the flow of molten steel, the plug brick will be separated from the nozzle brick, and the molten steel will flow out through the nozzle brick. This precise control is very important to ensure the casting quality, which can avoid the waste of molten steel and the occurrence of casting defects.

III. Production Process of Plug Brick

The production process of plug bricks includes the following steps:

Raw material preparation: Choose high-quality refractory materials as raw materials, such as high-alumina and corundum, which have high fire resistance and good corrosion resistance.

Batching and mixing: all kinds of raw materials are mixed according to a certain proportion, and a proper amount of binder is added for full mixing to make it have good plasticity and strength.

Molding: put the mixed mud into the mold and make the blank of the plug brick by pressing or grouting. It is necessary to strictly control the size and shape of the blank in the molding process to ensure that it meets the design requirements.

Drying and sintering: drying the molded green body to remove water, and then sintering in a high-temperature kiln. The control of firing temperature and time is very important for the quality of plug bricks, which can make them achieve the required fire resistance and strength.

Inspection and packaging: the fired plug bricks need to undergo strict quality inspection, including chemical analysis, physical performance test and appearance inspection, to ensure that they meet the quality standards. The qualified plug bricks will be packaged for transportation and storage.

IV. Importance of plug bricks in iron and steel industry

Plug bricks have irreplaceable importance in iron and steel industry. First of all, it can accurately control the flow of molten steel, ensure the smooth casting process and improve production efficiency. Secondly, the high quality of plug bricks can avoid the pollution and waste of molten steel and reduce the production cost. In addition, the service life of plug brick directly affects the maintenance cost of casting equipment, and its good corrosion resistance and wear resistance can prolong the service life and reduce the replacement frequency of equipment.

V. Conclusion

As a key refractory, plug brick plays an important role in steel casting. Its excellent performance and precise function make it an indispensable part of iron and steel industry. With the continuous development of iron and steel industry, the quality and performance requirements of plug bricks are getting higher and higher. Therefore, plug brick manufacturers need to constantly innovate and improve their production technology and improve product quality to meet market demand and make greater contributions to the development of iron and steel industry.