Effect of aluminum consumption and oxygen potential at final deoxidation on nozzle clogging of IF steel

By analyzing the composition and morphology of each layer IF steel clogs on the nozzle, it is found that aggregation and sintering of Al₂O₃ inclusions is the main reason for nozzle clogging. The effects of different aluminum consumptions on the stopper pole position were compared. When the quantity of aluminum consumption is large, the stopper pole position rises significantly. It may cause the casting accident of molten steel breakout while the quantity of aluminum consumption is more than 3.5 kg·t^-1. The average aluminum consumption and average oxygen potential at final deoxidation were defined. As the average aluminum consumption increases, the casting time decreases when a single submerged nozzle is used. When the quantity of average aluminum consumption is over 3.5 kg·t^-1, the casting time is less than 50 rain with a single submerged nozzle used. The aluminum consumption tends to increase with the improvement of oxygen potential at final deoxidation. When the oxygen potential at final deoxidation is more than 600×10^-6, the aluminum consumption may exceed 3.0 kg·t^-1. While the average oxygen potential at final deoxidation is more than 600×10^-6, the casting time with a single submerged nozzle is probably less than 50 min.