Refractory Lining of a Continuous Casting Tundish Dec23

Refractory Lining of a Continuous Casting Tundish...

Refractory Lining of a Continuous Casting Tundish In the continuous casting (CC) of steels, tundish is a buffer refractory lined vessel which is located between the ladle and the CC mould. The tundish serves the purpose of a reservoir  and a distribution vessel. Over the years, there have been dramatic changes in CC tundish. From a mere reservoir and distribution vessel, the tundish today  is viewed as a steel refining vessel and a totally new field in the process of steel making technology has emerged which is known as tundish metallurgy. Tundish today also fulfills certain metallurgical functions such as feeding of the liquid steel to the mould at a controlled rate, and thermal and chemical homogenization etc. It also focus on the continuous improvement of many quality related parameters such as fluid dynamics, thermal insulation, inclusion floatation and removal, and hydrogen pickup etc. Different refractories associated with tundish include tundish lining materials (both permanent and working lining), dams and weirs, impact pad, flow control system (monoblock stopper or slide gate), pouring stream protection between tundish and mould (shroud or submerged entry nozzle,SEN), tundish nozzle, and seating block. Dams and weirs are made of magnesite (MgO) boards or alumina (Al2O3) bricks. Liquid steel from tundish to mould is fed by nozzle submerged into molten steel in mould. SEN are to be resistant to corrosion and spalling, Nozzle clogging is also important. Isostatic pressed SEN with alumina graphite-fused silica are commonly used. Fig 1 shows typical tundish along with its refractories. Fig 1 Typical tundish along with its refractories The refractory lining design and quality of refractories used for lining have major influence on the operational parameters of CC machines such as super heat requirements, speed of the machine, the phenomenon like initial cold running stopper,...