Long nozzle and continuous casting method

Abstract

The invention discloses a long nozzle and a continuous casting method. The long nozzle comprises a durable material (1) and a steel sleeve (2) arranged outside the durable material in a sleeving way, wherein a hollow part (3) is arranged in the durable material; the durable material is sequentially provided with a gas inlet (4), an annular gas chamber (5) and a vent groove (6), which are communicated with one another, in the thickness direction; the vent groove extends in the thickness direction of the durable material to be communicated with the hollow part; a plurality of gas gaps are formed between the upper surface of the durable material and the steel sleeve, and are communicated with the top of the hollow part and the gas inlet respectively. According to the long nozzle, a double-sealing mode is adopted, a lower nozzle of a large ladle is primarily sealed through the gas inlet, the annular gas chamber and the vent groove by gas, and meanwhile, the combination part of the long nozzle and the lower nozzle of the large ladle can be secondarily sealed through the gas gaps formed by a plurality of bumps which are distributed on the upper surface of the durable material at intervals by the gas, so that double sealing effects are achieved, the sealing performance is high, the nitrogen increase of molten steel from the large ladle to a medium ladle can be effectively reduced, and the nitrogen increase of the molten steel in a continuous casting process can be controlled within 3ppm.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a shroud and a continuous casting method. Background technique [0002] For most steel types, nitrogen is a harmful element, and the nitrogen content in steel has a great influence on the mechanical properties of steel, especially when producing low-carbon steel and ultra-low carbon steel for deep drawing conditions, nitrogen is unfavorable The impact is particularly pronounced. Therefore, when producing high-grade, high-value-added low-nitrogen steel, the lower the nitrogen content in molten steel, the better. In the modern steelmaking production process, the production of low nitrogen steel is often realized through the control of nitrogen content in each process of steelmaking. [0003] The continuous casting process of molten steel is a process of increasing nitrogen, especially the process of molten steel flowing from the ladle to the tundish. Usually, a lon...

AI Technical Summary

Problems solved by technology

However, the traditional shroud nozzle is single-sealed, and the parameter control of argon blowing at the shroud nozzle is unreasonable, resulting in poor sealing effect between the shroud nozzle and the ladle lower nozzle, and the nitrogen increase of the molten steel is severe.

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