Types and Characteristics of Refractory Materials for Tundish Lining

The tundish is situated between the ladle and the continuous casting machine, featuring both a rectangular and T-shaped design. The refractory materials used for lining the tundish are varied. The permanent layer castable is composed of high-alumina bricks, forming a cohesive structure.

The working layer is fitted with a thermal insulation board, smearing material, and is integrally cast with dry castable. The materials used can be acidic, neutral, or alkaline. The tundish features a simple structure with a bottom and walls. Additionally, it includes nozzles and impact areas at the bottom, as well as overflow grooves or retaining walls along the side.

The tundish is the refractory lining that is the most frequently overhauled in steel plants. It must be used for future development, and the construction is quick and convenient. The permanent layer of the tundish is also made of high-aluminum castable, which is installed or painted as needed. If the permanent layer is cast as a whole, the cladding must be cleaned before pouring, and the tundish nozzle should be placed before demoulding. The bottom can then be poured with high-aluminum castable, ensuring the surface is flat and vibrated densely. During the mixing process, do not stop until it is complete, and allow the bottom to dry naturally for 24 hours before placing the mold for pouring the ladle wall. The gap between the cladding mold and the steel plate should be uniform, and the pouring of the high-aluminum castable should be consistent. The thickness of the stack should not exceed 300 mm. After natural curing for 24 hours, it can be demoulded and placed on the baking table.

If you use smears, the application process is straightforward. Begin by installing the nozzle, block, tundish impact plate, and slag retaining wall. Next, apply the mixed smear onto the permanent layer. Once the design thickness is achieved, pierce the heat dissipation holes. Ensure that the smear at the junction of the impact plate and the slag retaining wall is shaped into a slope. Additionally, the surface of the overflow tank should also be coated with tundish coating material.

In recent years, a significant amount of dry materials has been utilized. The construction process for dry materials resembles that of the permanent layer cast with high-aluminum castables. The mold is filled and vibrated, and after molding, the dry materials are evenly baked. Once they reach a specific temperature, they are demolded and subjected to further baking.

Key Characteristics of Refractory Materials

When selecting refractory materials for tundish lining, several key characteristics must be considered:

High Temperature Resistance: The ability to withstand extreme temperatures is critical to prevent premature wear and failure.

Chemical Resistance: Refractories must resist aggressive slag and molten metal, as chemical reactions can degrade material integrity.

Thermal Shock Resistance: Rapid temperature changes can cause cracks and damage; thus, materials should withstand such fluctuations.

Mechanical Strength: Adequate mechanical properties ensure that the lining can support the weight of the molten metal and withstand mechanical stresses.

Thermal Conductivity: Low thermal conductivity is desirable to maintain temperature within the tundish and optimize energy efficiency.

Conclusion

Refractory materials are essential for the effective operation of tundishes in steelmaking. Understanding the different types and their characteristics allows manufacturers to choose the right materials to enhance the performance and lifespan of their tundish linings. As a key element in steel production, the choice of refractory materials impacts not only operational efficiency but also the quality of the final product. If you're seeking a reliable supplier for refractory materials tailored to tundish lining, contact us today to discuss your specific needs and requirements.