Continuous casting nozzle

Abstract

A continuous casting nozzle 1 includes a nozzle main body 2 and a nozzle hole 3 formed to extend through the nozzle main body so that molten steel flows therethrough, and an alumina-hardly-adherable refractory 5 containing components of MgO, CaO and SiO₂ is disposed on an inner surface defining the nozzle hole. Consequently, even when a temperature of the nozzle is low, adhesion of inclusions in molten steel to a portion in contact with the molten steel can be reduced, with the result that the nozzle hole can be prevented from being blocked and the continuous casting nozzle can contribute to an improvement in the steel quality.

Description

TECHNICAL FIELD[0001]The present invention relates to a continuous casting nozzle used for continuous casting, such as an immersion nozzle, a long nozzle and a tundish upper nozzle for injecting molten steel from a tundish into a mold. More specifically, the present invention relates to a continuous casting nozzle which can contribute to prevention of inclusion adhesion and improvement in the steel quality by arranging a material reacting with inclusions present in molten steel on an inner hole surface.BACKGROUND ART[0002]In casting a steel slab, alumina inclusions in molten steel repeatedly adhere to, coalesce on and drop from an inner hole surface of a continuous casting nozzle to be taken into the steel slab together with the molten steel flow, resulting in a steel slab defect which degrades the quality of the steel slab. Furthermore, the alumina inclusions may adhere to the inner hole surface of the continuous casting nozzle, causing narrowing of the inner hole and subsequent bl...

AI Technical Summary

Benefits of technology

[0008]According to the continuous casting nozzle as claimed in claim 1, adhesion of inclusions in the molten steel to the portion in contact with the molten steel can be reduced even when the nozzle temperature is low, with the result that the nozzle hole can be prevented from being blocked and the continuous casting nozzle can contribute to an improvement in the quality of steel.

[0009]According to the continuous casting nozzle as claimed in claim 2, the continuous casting nozzle can be configured to have a higher thermal spalling resistance.

[0010]According to the continuous casting nozzle as claimed in claim 3, the aforementioned effect of claim 1 can be achieved more satisfactorily.

[0011]According to the continuous casting nozzle as claimed in claim 4, the aforementioned effect of claim 1 can be achieved more satisfactorily.

[0012]According to the continuous casting nozzle as claimed in claim 5, the aforementioned effect of claim 1 can be achieved more satisfactorily.

[0013]According to the continuous casting nozzle as claimed in claim 6, the aforementioned effect of claim 1 can be achieved more satisfactorily.

Problems solved by technology

In casting a steel slab, alumina inclusions in molten steel repeatedly adhere to, coalesce on and drop from an inner hole surface of a continuous casting nozzle to be taken into the steel slab together with the molten steel flow, resulting in a steel slab defect which degrades the quality of the steel slab.

Furthermore, the alumina inclusions may adhere to the inner hole surface of the continuous casting nozzle, causing narrowing of the inner hole and subsequent blockage.

However, this continuous casting nozzle has a problem that an inclusion adhesion reducing performance is not sufficiently exerted when a temperature of the nozzle decreases until molten steel flows through the nozzle hole from the time of completion of preheating.

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