Tundish Coating Description:
Tundish powder is a free flowing non-toxic and non-hazardous mixture. It seals the surface of the liquid steel in the tundish. It is also known by several other names such as tundish covering compound, tundish covering flux, tundish flux, tundish covering slag, or tundish flux slag. Tundish powder has got very good insulating properties. It plays an important role in the continuous casting of liquid steel and is one of the influential and critical factors in the stable operation of the continuous casting machine. The use of a suitable tundish powder is an essential feature of the present day tundish metallurgical practice. However, the selection of powder is specific to the grade of steel and product quality requirements.With the development of the high speed casting, tundish powder is becoming the key material for the continuous casting process and has more and more important and irreplaceable roles on the quality of the cast steel.
Tundish Coating Function:
1.To protect liquid steel against oxidation
2.To control, optimize, and insulate the heat transfer from the liquid steel to the ambient and thus prevent the drop in the temperature of the liquid steel
3. To absorb the non-metallic inclusions from the liquid steel to produce cleaner cast steel product
4.To provide chemical protection to the liquid steel from oxidation and other undesired reactions,
5. To be compatible with the refractory materials which are used as the containment materials in the tundish.
The Service Life of Tundish Coating Mixture
Generally speaking, the higher the CaO content is, the better the cleaning effect of tundish coating material will be. But there is no definite value of CaO content, and the high CaO content coating material is hard to produce.
The service life of magnesia calica tundish coating material is correlated with the thickness of the coating layer. Generally speaking, the continuous casting times is between 8 and 10 if the coating thickness is 35~40mm, while the continuous casting times is over 10 if the coating thickness is 40~60mm.