Explanation

It is also called off furnace refining or secondary metallurdy. In the later stage of the steelmaking process, the composition and temperature of liquid steel can reach the predetermined requirements through steel mixing, powder spraying, slagging metallurgical technology, ferroalloy addition, vacuum treatment and other methods. refining is mainly to remove the impurity elements harmful to the quality of steel, reduce the inclusion content and carry out inclusion modification treatment, deoxidation and degassing, adjust and homogenize the composition of liquid steel, and accurately adjust the temperature of liquid steel. In modern steelmaking process, steel liquid melting in primary smelting furnace (converter, electric furnace or open hearth furnace) is often transferred to another container (such as ladle, vacuum furnace, etc.) for refining, so refining is also called off furnace refining or secondary metallurdy. The adoption of off furnace refining and staged steelmaking can improve product quality, shorten smelting time, improve production efficiency of steelmaking equipment, simplify process flow and reduce production cost.

Classification