Quasi-four-hole submersed nozzle for FTSC (flexible thin-slab casting) mold

Abstract

The invention relates to the field of metallurgical continuous casting equipment nozzles, in particular to a quasi-four-hole submersed nozzle for an FTSC (flexible thin-slab casting) mold. The quasi-four-hole submersed nozzle comprises an upper liquid steel inflow end, a middle flow channel and a lower outflow end which are sequentially connected, bilaterally symmetric discharge holes are arranged at the lower outflow end, and split-flow bodies are arranged between the discharge holes. The quasi-four-hole submersed nozzle is characterized in that middle flow guide bodies are arranged in the discharge holes, and four discharge channels are formed at the lower outflow end. Compared with the prior art, the quasi-four-hole submersed nozzle has the advantages that by the aid of lower flat structures of four basically downward discharge holes with proper opening, flow of liquid steel on the periphery of the nozzle is facilitated, a slab shell in solidification is prevented from being adhered with the nozzle, the structural sizes of a liquid steel inner channel and the outflow end of the nozzle are optimized in design, vortex core positions of two symmetric swiveling areas formed below the four discharge channels of two discharge openings, and floating nonmetal inclusions in the liquid steel can be absorbed and removed by covering slag.

Description

Technical field [0001] The invention relates to the field of metallurgical continuous casting equipment nozzles, in particular to a quasi-four-hole immersion nozzle for FTSC thin slab continuous casting molds. Background technique [0002] The thickness of the slab produced by the Flexible Thin Slab Caster (FTSC) developed by Danieli Company of Italy is generally between 65-92mm and the width is about 900-1650mm. The FTSC thin slab caster is different from the flat mold commonly used in the conventional slab caster. The mold of the FTSC thin slab caster is similar to the CSP thin slab caster, and its wide copper plates have continuous arcs. The curved surface composed of the transition, the entire mold is "funnel-shaped", but the shape and size of the "funnel" surface of the two kinds of molds are different. The increase in the upper space of the molten steel pool in the funnel-shaped mold makes it possible to use immersion nozzles and continuous casting mold powder for thin sla...

AI Technical Summary

Problems solved by technology

Figure 7 The four-hole submerged nozzle shown in the figure directly transports the high-temperature molten steel to the liquid surface of the molten pool around the nozzle through two upward spout holes (7). The impact fluctuation of molten steel jet on the liquid surface of the molten steel pool of the mold is relatively serious, and the high temperature area of ​​the molten steel surface in the molten pool is only concentrated around the nozzle, which makes the temperature distribution of the entire molten steel surface uneven

Figure 8 The shown is an improved four-hole submerged nozzle, relying on the upper part of the upward spout hole (7) to form a substantially horizontal flow of molten steel jet to suppress the circulation flow in the mold caused by the downward spit hole (8) of molten steel jet , so that the fluctuation of the liquid steel level in the molten pool has been improved to a certain extent, but at the same time it has also caused the negative effect of non-metallic inclusions floating up, so it is not suitable for continuous casting production of varieties of steel that require high billet cleanliness

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