CONTINUOUS CASTING METHOD

To provide a continuous casting method capable of efficiently floating and separating inclusions and stably suppressing the entrainment of the suspended inclusions into molten steel more than before.SOLUTION: The molten steel in the ladle is charged into a tundish 11 by using a long nozzle 10 provided with a side discharge hole 12 so that Uobtained from the following equation is less than 0.043. U={(α×W)/(ρ×π×d×x)}×(S/S)×sinθ x=L/sinθ where, Uis flow velocity of molten steel in the vertical direction at a molten steel surface position of the discharge flow, θ: upward discharge angle of the side discharge hole, x: distance of the molten steel surface from the side discharge hole in the discharge angle θ direction, α: decay constant of the molten steel flow velocity at the distance x from the side discharge hole, W: amount of charged molten steel per unit time from the ladle, ρ: density of molten steel, d: radius of the side discharge hole, S: area per side discharge hole, S: total area of all the discharge holes, and L: vertical distance of the molten steel surface from the center of the side discharge hole.SELECTED DRAWING: Figure 1 【課題】介在物を効率的に浮上分離させると共に、浮上分離された介在物の溶鋼中への巻き込みを、従来よりも安定して抑制可能な連続鋳造方法を提供する。【解決手段】側部吐出孔１２が設けられたロングノズル１０を用いて、下式から求められるＵＣ,Ｚが０．０４３未満となるように、取鍋内の溶鋼をタンディッシュ１１内に注入する。ＵＣ,Ｚ＝｛（α×Ｗ）／（ρ×π×ｄ×ｘ）｝×（ＳＳｉｄｅ／ＳＡｌｌ）×ｓｉｎθｘ＝Ｌ／ｓｉｎθここで、ＵＣ,Ｚ：吐出流の湯面位置での鉛直方向の溶鋼流速、θ：側部吐出孔の上向き吐出角度、ｘ：吐出角度θ方向の側部吐出孔から湯面の距離、α：側部吐出孔からの距離ｘでの溶鋼流速の減衰定数、Ｗ：取鍋からの単位時間当たりの溶鋼注入量、ρ：溶鋼の密度、ｄ：側部吐出孔の半径、ＳＳｉｄｅ：側部吐出孔１つ当たりの面積、ＳＡｌｌ：全吐出孔の総面積、Ｌ：側部吐出孔の中心から湯面の鉛直距離、である。【選択図】図１