The key to achieving low superheat casting is: (1) control inclusions in steel to prevent nodulation of the water outlet during the low superheat casting process;
(2) Accurately control the temperature stability of the molten steel in the process of continuous casting;
(3) Stable control of steelmaking one-continuous casting production rhythm.
In order to control the composition of inclusions in steel, calcium treatment technology is generally used, but when the sulfur content in steel is high, CaS inclusions are easy to form and lead to mouth nodulation, and the punctate inclusions formed by calcium treatment are very harmful to some steels. The use of low-aluminum clean steel technology achieves the dual purpose of improving cleanliness and optimizing inclusions. At present, the temperature of molten steel can be controlled within a narrow range through secondary refining, and the use of tundish insulation technology and steel inclusion control technology creates conditions for low superheat casting. Studies have shown that the most effective means to control the temperature stability of tundish steel is to use plasma heating device to supplement tundish with stable and reliable neutral thermal energy. In addition, to reduce the superheat of molten steel, it is also possible to consider using a water cooling nozzle or auxiliary cooling with a conical non-consumable condenser on the meniscus of the molten steel.
