Sizing nozzle casting method utilized by tundish of small square billet continuous casting machine in steelmaking enterprise

Abstract

The invention discloses a sizing nozzle casting method utilized by a tundish of a small square billet continuous casting machine in a steelmaking enterprise. The method is characterized in that (1), the temperature of sizing starting-up molten steel is 1605 DEG C to 1630 DEG C, the temperature under a normal casting state is 1575 DEG C to 1595 DEG C, and the temperature of the tundish is larger than 1570 DEG C when casting is started and is less than or equal to 1550 DEG C under a normal casting state; (2), sizing casting and pulling speed is controlled, the starting pulling speed is 1.2 m/min, and the temperature pulling speed is 1.2 to 3 m/min; (3), the liquid level of the tundish is controlled, and the depth of the molten steel in the tundish is controlled at 450 to 750 mm; and (4), key points of the sizing are characterized in that a, continuous baking is carried out on the tundish for more than 60 minutes according to the order of soft fire, middle fire and large fire, b, dummy ingot feeding and plugging and cooling strip placing are carried out, and c, starting operation is carried out, the emergence time is longer than 13 seconds, and the method of pulling speed automatic control is adopted. According to the method, casting of molten steel flow injected into a crystallizer is controlled through the inner diameter of the sizing nozzle, a stopper rod and a stopper rod control mechanism are not needed, the control of the flow of the sizing nozzle is relatively stable, the improvement of the quality of the continuous casting blank is facilitated, automatic casting is realized, and the labor intensity of workers is reduced.

Description

technical field [0001] The invention belongs to the technical field of steelmaking, in particular to a method for casting a tundish of a billet continuous casting machine in a steelmaking enterprise using a sizing nozzle. Background technique [0002] Billet continuous casting sizing pouring technology is a new technology, which is a pouring method that does not need a stopper but relies on the inner diameter of the nozzle to control the flow of molten steel injected into the mold. The advantages of this method are: no stopper rod and stopper rod control mechanism are needed, the cost of refractory materials and equipment spare parts is reduced, and the flow control of the sizing nozzle is relatively stable, which is beneficial to the improvement of the quality of the continuous casting slab. At the same time, automatic pouring can be realized and the labor intensity of employees can be reduced. [0003] At present, the billet continuous casting machine mainly adopts the st...

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Problems solved by technology

[0003] At present, the billet continuous casting machine mainly adopts the stopper rod to control the casting mode. Due to the design characteristics of this casting method, the molten steel is easy to turn out from the upper part of the nozzle when pouring, which affects the normal pouring of continuous casting, not only affects the improvement of casting speed, but also affects the casting speed. Moreover, the turned-out molten steel tends to accumulate around the crystallizer, resulting in the failure of pouring, resulting in the inability to accurately control the size of the injection flow during the production process, and frequent accidents of stopper rod out of control

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