The nozzle clogging in the continuous casting of the steel the nozzle clogging

摘要

PROBLEM TO BE SOLVED: To provide a method for achieving a stable continuous casting operation without clogging a ladle nozzle and an immersion nozzle.;SOLUTION: A method for preventing the clogging of the nozzle, is performed as the followings, by which FeSi, FeMn, FeP, FeCr alloys are added into molten steel exceeding 50 ppm soluble oxygen concentration so as to become ≥80% of the aimed concentration shown with mass% in each element to the aimed Si, Mn, P, Cr concentrations in a molten steel in a tundish or a cast slab. Further, the method for preventing the clogging of the nozzle, is performed as the followings, in which total Ca mixed quantity from these alloys is limited so that the charging quantity of the added FeSi, FeMn, FeP, FeCr alloys satisfies the following formula (A) after Al-deoxidation. That is, the above (A) formula is Total Ca mixed quantity=(0.5×W_FeSi×Ca_FeSi/100+0.01×W_FeMn×Ca_FeMn/100+0.02×W_FeP×Ca_FeP/100+0.005×W_FeCr×Ca_FeCr/100)/W_steel×10⁶≤6. Wherein, W_i(kg) is added quantity of i alloy after Al deoxidation, W_steel(kg) is molten steel quantity and Ca_i(mass%) is Ca concentration in the ferro-alloy i.;COPYRIGHT: (C)2006,JPO&NCIPI