Out-of-furnace refining can homogenize the temperature and chemical composition of continuous casting molten steel, adjust the molten steel temperature, adjust the molten steel composition, remove harmful elements, reduce the gas content in the molten steel, change the shape and composition of inclusions in the steel, and clean the molten steel as needed. , especially to ensure that large inclusions do not exceed the standard and improve the fluidity of molten steel. The out-of-furnace refining equipment can also play a role in coordinating the production rhythm between continuous casting and steelmaking, so that production runs smoothly.
Why does high-efficiency continuous casting put special emphasis on ensuring the temperature of the molten steel
Appropriate molten steel temperature (different steel grades have different temperature requirements) can enable efficient continuous casting to obtain high-quality slabs, while the superheat of molten steel is increased, the billet shell is thinned, molten steel is easy to secondary oxidation, inclusions If it increases, the refractory material is seriously eroded, and a series of problems such as bulging, breakout, columnar crystal development, serious center segregation, and serious shrinkage are prone to occur. The production practice and theory of high-efficiency continuous casting have reached the same conclusion, that is, low-temperature casting is one of the important means to increase the pulling speed and improve the quality of the slab. Of course, there must be a limit when the temperature is low. If the temperature is too low, there will be problems such as poor fluidity of molten steel, freezing of the nozzle, and difficulty for inclusions to float. Therefore, high-efficiency continuous casting emphasizes the need to ensure the temperature of the molten steel, that is, the temperature of molten steel is uniform and stable to ensure that it is within the specified range.