The Simulation of Oxide Inclusions Transformation during Reoxidation of LCAK-Steel
Abstract
It is known that nozzle clogging during casting of low carbon low silicon aluminum killed steel is greater then one during casting of LCAK steel contained silicon. It is obvious that silicon content variation in range from 0.01 to 0.02 wt. pct. cannot influence on equilibrium oxides composition, taking into account that aluminum amount in these grades is more then 0.02 wt. pct. But silicon content in the melt can effect on composition of nonequlibrium reoxidation products, which appear in the melt stream inside the nozzles and on the transformation of primary oxides (calcium aluminates) if soluble oxygen increases because of the reoxidation. Transformation of reoxidation products and primary oxides was simulated for 08K (wt. pct.: 0.2 [Si], 0.025 [Al]) and 08Yu (wt. pct.: 0.02 [Si], 0.05 [Al]) steel. We used own software for simulation of oxide inclusions transformation after reoxidation. It was found that transformation time for these grades is visibly different. Transformation of initially liquid oxides (on base of FeO as well as primary calcium aluminates) to solid inclusions (on base of Al2O3 with a touch of CaO) in 08K steel takes 2.5 – 3 times more then in 08Yu steel. Therefore, the probability that oxides in liquid state leave the nozzles and SESs for 08K steel is greater then for 08Yu steel.
Key words: continuous casting, LCAK steel, 08Yu, 08K steel, nozzle clogging, reoxidation, computer thermodynamic simulation, nonmetallic inclusions
