Fire resistance and application of plug brick

I. Fire resistance

The refractoriness of plug brick refers to its resistance to melting at high temperature, which is one of the important indexes to measure the properties of refractory materials. According to the search results, the fire resistance of plug bricks varies with the material composition and production process:

Clay plug brick: The fire resistance is usually between 1690℃ and 1730℃.

High-alumina plug brick: the fire resistance is higher, for example, the fire resistance of SK-34 grade high-alumina brick is 1750℃, and the fire resistance of SK-38 grade high-alumina brick can reach 1850℃.

Graphite plug brick: Because of the high melting point of graphite, graphite plug brick has high fire resistance and is suitable for high temperature environment.

II. Uses

Plug bricks are mainly used for continuous casting and die casting in steel production, and their main uses include:

Control the flow of molten steel: the plug brick is installed at the lower end of the plug rod and closely cooperates with the nozzle brick. When not pouring, the plug brick blocks the nozzle to prevent molten steel from leaking; When pouring, by lifting the stopper rod, a gap is generated between the stopper brick and the nozzle brick, and molten steel flows out of the nozzle.

Adjusting the molten steel flow: By controlling the lifting height of the stopper, the outflow of molten steel can be accurately adjusted, thus achieving accurate control of the pouring process.

Protection equipment: the high refractoriness and good thermal shock resistance of the plug brick make it stable in high temperature environment and protect the tundish and nozzle brick and other equipment.

Improve the purity of molten steel: due to the refractory characteristics of the plug brick, it will not release impurities at high temperature, thus ensuring the purity of molten steel.

III. Other characteristics

Thermal shock resistance: the plug brick has good thermal shock resistance and can maintain structural integrity in frequent temperature changes.

Wear resistance and corrosion resistance: the wear resistance and corrosion resistance of plug brick make it able to resist the erosion and chemical erosion of molten steel.

Low porosity: Low porosity is helpful to reduce the penetration of molten steel and further improve the sealing performance.

To sum up, plug brick plays a key role in steel production with its high refractoriness, good thermal shock resistance and wear resistance, and is an important refractory material to ensure the smooth pouring process.