| 摘要 |
PROBLEM TO BE SOLVED: To provide a continuous casting method capable of continuously casting medium to high carbon steel, in which solidification is apt to delay, with high productivity. SOLUTION: An immersion nozzle is used, which has a pair of molten steel discharge holes 3. The discharge holes 3 opposite to each other are formed at the positions of the peripheral wall of the immersion nozzle, which are separated upward by a predetermined distance from the inside bottom surface of the nozzle, and further a projection 4 is extended on the inside bottom surface of the nozzle. When the height (mm) of the projection 4 is h, the width (mm) of the extending direction edge of the projection 4 is a, the width (mm) of the extending direction middle of the projection 4 is b, and the inner diameter (mm) of the immersion nozzle is Dsn, the following formulae (1) and (2) are satisfied, the formula (1): h/H=0.5-2.0 and the formula (2): (a-b)/Dsn=0.15-0.45. The casting speed Vc (m/min) is made to be 1.4-2.2, and the molten steel superheat degreeΔT (°C) is made to be 20-45. COPYRIGHT: (C)2009,JPO&INPIT
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