Study on Clogging Mechanism of Submerged Entry Nozzle for Continuous Casting of Ferritic Stainless Steel Containing Ti

The types of inclusions and the phases of clogging of submerged entry nozzle in 00Cr18Ti stainless steel were investigated by optical microscope and scanning electron microscope(SEM), and meanwhile the mechanism of nozzle clogging was studied.The results showed that a lot of titania inclusions existed in molten steel, and some of them adhered and precipitated to the interface of nozzle, which led to clogging.The formation of mass titania inclusions was depressed, and the phenomenon of titania clogging of submerged entry nozzle was avoided by controlling the contents of w_[Al]-w_[Ti] below the equilibrium curve of competitive oxidation reaction between [Al] and [Ti], that is w_[Ti]/w_[Al]^4/3 less than 273.55.