| 摘要 |
PROBLEM TO BE SOLVED: To prevent a pencil pipe defect within steel by directing gas containing nitrogen toward a flow passage part which is formed of an upper tundish nozzle or the like under a scheduled condition of gas flow. SOLUTION: A flow passage P is formed of an upper tundish nozzle 14 which is arranged just under a tundish 12, a throttle plate 48 which controls the flow of molten metal, and an immersion entry nozzle 18 which is arranged between the throttle plate 48 and a casting mold 20. Molten steel M is made to flow through the flow passage P. The gas containing nitrogen is directed toward the flow passage P part which is formed of the upper tundish nozzle 14, the throttle plate 48 and the immersion entry nozzle 18 under a scheduled condition of gas flow. The gas containing nitrogen is made to flow at a flow rate within the range of nearly 8-12 l/min, nearly 2-6 l/min and nearly 2-6 l/min through the upper tundish nozzle 14, the throttle plate 48 and the immersion entry nozzle 18, respectively.
|
