The definition and functionality of the tunpackage
tundish is a refractory container used in the continuous casting process of steelmaking. It is mainly used to receive the molten steel poured from ladle and then distributed to various crystallizers by the tundish nozzle. Its main functions include reducing the static pressure of molten steel, promoting inclusions to float up, diverting molten steel and storing molten steel.
metallurgical function of tundish
Tundish has a variety of metallurgical functions in steelmaking:
purification function : by adding dam to the retaining wall, argon blowing, ceramic filter and other measures, the content of non-metallic inclusions in steel can be greatly reduced.
temperature control function : by adding small pieces of scrap steel to the tundish, blowing iron powder and other measures to adjust the temperature of molten steel, to ensure that the temperature change during the pouring process is less than 5℃.
composition fine-tuning : Fine-tuning of microalloy composition in steel is achieved by feeding cored wire into the mold.
refining function : Add double layer slag on the surface of molten steel to absorb inclusions floating up, or feed calcium wire in the tundish to change the form of inclusions and prevent water nozzle blockage.
The structure of the tundish
The structure of a tundish usually consists of three layers:
permanent layer : the thickness is 100 ~ 200mm, mainly plays the role of safety insulation.
working layer : the thickness is 20 ~ 50mm, and it is in direct contact with molten steel, requiring the material to have good baking adaptability and strength.
thermal insulation : used to maintain the temperature of the tundish, usually aluminum silicate felt.
The material of tundish and its importance
The material of tundish is crucial to its efficiency and effectiveness in the steelmaking process. Commonly used materials include:
permanent lining material : Al-Si castable is usually used, which has good strength, volume stability and thermal shock resistance.
work lining material : alkaline dry material, composed of sintered magnesia, magnesia calcium sand, etc., has the advantages of simple construction and high baking efficiency.
summary
Tundish plays a vital role in steelmaking process. Through its metallurgical function and reasonable structural design and material selection, it can effectively improve the purity, temperature uniformity and composition control of molten steel, thus significantly improving the quality of casting billet and production efficiency. Extending the service life of tunic can not only reduce the production cost, but also reduce the number of spare packages and improve the efficiency of the overall production system.
