Continuous Casting of Refractory Materials
Continuous casting is one of the most commonly used casting methods. It involves pouring molten metal into a series of molds, which are placed one behind the other on a conveyor line. The molten metal is then cooled, solidified, and discharged onto a nearby conveyor belt. Refractory materials are used in continuous casting to protect the molds and the conveyor belts from thermal and mechanical damage, as well as insulate the molten metal from the environment.
Refractories are material substances with high melting points, which have the ability to remain thermally stable even when subjected to high temperatures. The most commonly used refractory materials for continuous casting are magnesia-carbon bricks, alumina-zirconia bricks, and zirconia-yttria refractories.
Magnesia-carbon bricks are a relatively lightweight refractory material composed of magnesia, carbon, and other elements. They possess a high thermal shock resistance, due to their high hydrogen content, and they are resistant to chemical attack. Magnesia-carbon bricks also offer good thermal insulation, making them ideal for continuous casting applications.
Alumina-zirconia bricks are composed of ceramic materials such as alumina and zirconia. They offer very good thermal insulation and high resistance to thermal shock. Alumina-zirconia bricks are also highly resistant to chemical attack, making them an ideal choice for application in continuous casting.
Zirconia-yttria refractories are a type of zirconia-based refractory made from yttrium oxide and zirconium oxide. Offering excellent thermal shock resistance and superior corrosion resistance, zirconia-yttria refractories are also very durable and long-lasting. They are also suitable for very high temperature applications, such as those used in continuous casting.
The choice of refractory material for a continuous casting application largely depends on the casting conditions and the type of material being cast. Refractory materials must therefore be carefully selected to ensure their compatibility with the specific application and to ensure long-term reliability and cost efficiency.
Continuous casting is one of the most important and reliable methods available for producing cast materials in large quantities. Refractory materials are not only essential for protection against thermal and mechanical damage, they also play an important role in insulating the molten metal from the environment. Accordingly, it is important to select the right refractory materials to ensure the successful outcome of a continuous casting application.
