The service life of plug brick varies with many factors, including its material, service conditions, molten steel temperature and composition. The following is the analysis of the common range and influencing factors of plug brick life under different conditions:

I. Common service life range

Ordinary clay plug brick: the service life is generally 1 ~ 4 times.

High-alumina or zircon plug brick: when used for casting high-temperature molten steel or special steel, the service life is relatively longer, generally up to 3 ~ 5 times.

Optimized plug brick: By improving the material and technology, the service life can be significantly improved. For example, excellent talent Division of Tangshan Iron and Steel Co., Ltd. has improved the service life of plug bricks to more than 30 hours by optimizing the material and tundish structure.

II. Factors affecting service life

(1) Material

Clay: The cost is low, but the corrosion resistance is relatively weak. It is suitable for ordinary steel grades and has a short service life.

High alumina: It has higher fire resistance and corrosion resistance, and is suitable for high-temperature steel with longer service life.

Zirconium: Excellent corrosion resistance and thermal shock resistance, suitable for special steel grades and long service life.

Silicon carbide (SiC) reinforced material: If silicon carbide particles are added to the plug brick, the corrosion resistance and service life can be significantly improved.

(2) Conditions of use

Temperature of molten steel: the corrosion of plug bricks by high-temperature molten steel is more serious, which shortens the service life.

Composition of molten steel: molten steel containing CaO and other components will accelerate the erosion of plug bricks.

Pouring technology: frequent opening and closing operations and temperature fluctuations will accelerate the thermal shock damage of plug bricks.

(3) Structural design

Shape of plug brick: The cone-shaped head has higher flow control accuracy and more erosion resistance than the hemispherical head.

Tightness of fit: the fit between plug brick and nozzle brick must be tight to avoid leakage and erosion of molten steel due to excessive gap.

III. Measures to prolong service life

Optimized material: high alumina, zircon or silicon carbide reinforced materials are used.

Improved structure: the brick part of the plug head is designed as a cone to improve the flow control accuracy and erosion resistance.

Process optimization: control the temperature and composition of molten steel to reduce the corrosion of plug bricks.

Regular maintenance: clean and repair the eroded parts in time and replace them if necessary.

To sum up, the service life of plug brick is affected by the material, service conditions and process design. By optimizing these factors, its service life can be significantly prolonged and the efficiency and stability of continuous casting production can be improved.