A review of domestic and foreign experience of steel treatment in CCM tundishes

The modern steelmaking facilities melt as a rule a semi product, which is further subjected to various processes of refining in steel ladle. Recently an additional treatment of the metal in CCM tundish became widespread in the domestic and foreign practice. A tendency of transforming tundish into a multifunctional metallurgical reactor was noted, since more and more technological operations are transferred in it, including alloying, stirring, various methods of heating, modifying and removal of nonmetallic inclusions. Examples of comprehensive utilization of a bloom CCM tundish at some Japanese plants of Kobe Steel in Kakagava presnted, at which the metal is filtered when going through holes in the two partitions thus effectively removing nonmetallic inclusions. New variants of metal blowing off in the tundish by inert gas developed by domestic specialists considered, including a technology for metal blowing off by an inert gas and a facility for the inert gas supply through the stopper of the tundish. Supply of inert gas through the stopper results in efficiency increasing of degassing and nonmetallic inclusions removal as well as submerged nuzzles service time increase, which is particularly important at casting of steels with high content of aluminum. Examples of solutions of metal treatment in tundish by cored and aluminum wire given. Schemes of cored wire introduction into tundish and liquid steel treatment in a CCM mold considered. Considerable attention was given to the problem of metal temperature control in tundish, including by an electric arc, induction and plasma heating. List of domestic and foreign plants presented, implemented facilities of steel plasma heating in the CCM tundish. It was noted, that steel chemical heating in tundish can be applied at unforeseen problems arising at casting.