JPH0796355A - Flat nozzle for continuous casting of wide and thin slabs - Google Patents

Abstract

(57) [Summary] [Object] The present invention provides a flat nozzle for continuous casting of a wide wide thin-walled slab, which has a slit-shaped nozzle hole in the lower portion, is easy and inexpensive to manufacture the nozzle body, and is strong. It provides a substructure. [Constitution] The nozzle body has a vertical inner surface or an inclined surface that spreads upward, the upper end of which is an open end, and a horizontal slit is formed in the lower part of the nozzle body. It is a flat nozzle for continuous casting of wide and thin cast pieces characterized by arranging a fireproof lid with an insertion hole.It is easy to pull out the mold for forming the inner side surface at the time of manufacturing the nozzle main body, which reduces the manufacturing cost. It can be greatly reduced. Further, it is strong because it is integrally formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous casting device for a wide and thin cast piece such as a twin drum type continuous casting device, which is used when a molten metal is supplied from a tundish into a moving mold, and has a slit nozzle at the bottom. The present invention relates to the structure of a flat nozzle having holes.

[0002]

2. Description of the Related Art In continuous casting using a twin-drum type continuous casting apparatus generally known in the prior art, FIG.
, A pair of rotating cooling drums Ra, R
b and side weirs Sa, S abutting on both end faces of this drum
The molten metal e is supplied from the inside of the tundish through the inner nozzle a and the outer nozzle b into the moving mold formed by b.
While forming a puddle p of a predetermined level in the moving mold, it is cooled by a cooling drum to form a solidified shell, and this solidified shell is pressure-contacted and integrated in a gap formed in the closest portion of a pair of cooling drums. A wide and thin slab c is obtained. At this time, in order to obtain a homogeneous thin cast piece,
It is necessary to suppress the positional fluctuation of the meniscus formed in the moving mold as much as possible, and therefore the role of the nozzle for supplying the molten metal into the moving mold is important.

In order to meet such a demand, for example, in the invention of Japanese Patent Laid-Open No. 63-203254, a filter f made of a porous refractory material having slit-shaped nozzle holes o in the side wall of the cooling drum near the lower closed end is formed. And a flat nozzle incorporating the fusible metal member d has been proposed.

The nozzle shown here is shown in FIG.
Since it has a complicated shape as shown in (b), it is almost impossible to integrally manufacture this nozzle with a refractory material. For this purpose, the nozzle body is installed on the upper b1 and the lower b2.
It is divided into two parts and manufactured, and these are assembled and integrated.

This separately manufactured upper part b1 and lower part b2
When assembling, it is necessary to secure sufficient sealing performance so that air in the atmosphere does not enter this assembly part, and precision processing is required to secure the surface accuracy of this assembly part. Is quite expensive.

On the other hand, as a means for assembling, it can be said that pin connection, adhesion, and a combination thereof are generally used. After the continuous casting is started, foreign matters are gradually deposited on the upper surface of the filter f incorporated in the nozzle body, and the nozzle is When the internal pressure applied to the main body rises, the nozzle main body often breaks starting from the combined portion of the upper part b1 and the lower part b2.

As a method of strengthening the nozzle body, it is conceivable that the material used is of higher grade, the number of pins is increased in the case of pin connection, the use of high-strength pins, etc., but there is a limit to that, and the fundamental solution is I won't.

[0008]

DISCLOSURE OF THE INVENTION The present invention has a flat nozzle for continuous casting of a wide thin-walled slab, which has a slit-shaped nozzle hole in its lower portion, is easy and inexpensive to manufacture a nozzle body, and is strong and has high pressure resistance. A nozzle structure is provided.

[0009]

According to the present invention, in a nozzle body, an inner surface of a side wall of the nozzle body is a vertical surface or an inclined surface that spreads upward, an upper end thereof is an open end, and a horizontal slit is formed in a lower portion. A flat nozzle for continuous casting of wide and thin cast slabs, characterized in that a fireproof lid having an insertion hole for an intermediate nozzle is provided at the upper end of the nozzle body.

[0010]

According to the present invention, the inner surface of the side wall of the nozzle body is a vertical surface or an inclined surface that spreads upward, and the upper end thereof is an open end. Therefore, it is easy to pull out the mold for forming the inner surface of the side wall when manufacturing the nozzle body. Since the nozzle main body can be integrally formed, the upper and lower assembling work as in the prior art can be omitted, the nozzle manufacturing process can be significantly shortened, and the manufacturing cost can be significantly reduced. Further, since the nozzle body is integrally formed and is strong, it is possible to stabilize the supply of the molten metal into the moving mold for a long period of time and stably maintain the continuous casting operation. Also, the effect of reducing the cost of refractories can be expected.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the embodiments shown in FIGS. The flat nozzle 1 of the present invention comprises a main body 2 integrally formed with a fireproof lid 3 disposed on the upper end thereof, and is horizontally arranged on both side walls on the cooling drum side near the lower closed end of the main body 2. The slit-shaped nozzle hole 4 is formed laterally, and the fireproof lid 3 is formed with an insertion hole 6 into which the intermediate nozzle 5 is inserted. A filter 8 made of a porous refractory and a meltable metal 7 for applying a pressure loss to the molten metal from the nozzle hole 5a of the intermediate nozzle 5 is built in the bottom of the main body 2.

In the flat nozzle 1 of the present invention, the inner side walls 2a and 2b of the main body 2 on the side of the cooling drum are vertical faces, and the inner side faces 2c and 2d of the side wall on the side of the cooling drum are inclined faces that widen upward. Has become. In addition, the side wall side wall inner surfaces 2e and 2f are formed as vertical surfaces, and the upper end of the main body 2 is an open end.

The nozzle body 2 is made of, for example, Al ₂ O ₃ −.
An outer molding frame and an inner molding frame are used for manufacturing the C type refractory, and the outer surface of the inner molding frame that forms the inner wall of the main body 2 is the same as the inside of the main body side wall. Therefore, the inner molding frame can be easily pulled out from the inside of the main body 2 molded using this inner molding frame.

After the main body 2 is molded, dried and fired in this way, horizontal slit nozzle holes 4 are formed in both side walls on the cooling drum side near the lower closed end of the main body 2 by machining or the like. The filter 8 and the fusible metal 7 are arranged on the bottom of the main body 2, and the refractory lid 3 is arranged on the upper end to form the flat nozzle 1 of the present invention.

The price of the nozzle body 2 obtained by the present invention is
The width is 680 mm and the thickness is about 20 mm, which is about 1/3 of the case of a conventional flat nozzle in which the upper and lower parts are manufactured separately and the upper and lower parts are assembled by using a connecting pin and an adhesive. Since the fireproof lid 3 may be an inexpensive precast block or the like, it can be made considerably inexpensive.

Further, since the nozzle main body 2 is integrally formed, it is strong, and after the continuous casting is started, the filter 8
Even if foreign matter gradually accumulates on the upper surface and the internal pressure applied to this nozzle body rises, unlike the conventional case, this nozzle body will not be destroyed for a long time and there is no connecting part.
There is no concern that the continuity of the molten metal will deteriorate due to the entrainment of air in the atmosphere.

FIG. 3 shows a state in which the flat nozzle 1 of the present invention constructed as described above is fixed to the lower part of the tundish 9. A refractory 11 is lined inside the outer skin 10 of the tundish 9 at the bottom.
2, an intermediate nozzle insertion hole 13 is provided. The insertion hole 13 is an inclined hole whose diameter decreases downward, and penetrates the outer skin 10.

An intermediate nozzle 5 whose upper outer peripheral surface is a tapered surface which is locked to the inner surface of the insertion hole is inserted and disposed in the insertion hole 13 from the inside of the tundish 9. The lower end of this intermediate nozzle is a closed end, and nozzle holes 5a and 5b are provided in the side wall in the vicinity thereof.

Above the intermediate nozzle 5, a stopper 14 for controlling the amount of molten metal supplied from the tundish 9 into the moving mold is arranged so that its vertical position can be adjusted. That is, by adjusting the gap between the upper end surface of the intermediate nozzle 5 and the lower end surface of this stopper, the amount of molten metal supplied into the moving mold can be controlled.

The lower portion of the intermediate nozzle 5 is inserted into the insertion hole 6 of the fireproof lid 3 provided at the upper end of the flat nozzle 1 of the present invention. The flat nozzle 1 is fixed by a support 15 and a movable support 16 fixed to the support by bolts and nuts 17.

As described above, after inserting the intermediate nozzle 5 into the flat nozzle 1 of the present invention and positioning it at a predetermined position, the lower portion of the flat nozzle 1 and the filter 8 are connected to the electric heating electrode 18.
Preheat with raising the stopper 14 to form a predetermined gap between the lower end surface of the stopper and the upper end surface of the intermediate nozzle 5, and supply the molten metal from the tundish 9 to the flat nozzle 1 through the intermediate nozzle 5. The flattening nozzle 1 is filled with the molten metal by the pressure loss effect of the fusible metal 7 and the filter 8,
This molten metal is densely continuous between the tundish 9, the intermediate nozzle 5 and the flat nozzle 1, and is supplied into the moving mold through the slit-shaped nozzle hole 4 below the flat nozzle 1 to form a molten metal pool of a predetermined level. , Continuous casting. After the shift to the steady operation, the position of the stopper 14 is adjusted and the molten metal supply amount is controlled so that the position of the meniscus in the moving mold does not fluctuate as much as possible. In the flat nozzle 1 of the present invention, continuous casting operation can be stabilized for a long time, and a homogeneous thin cast piece can be stably cast.

The present invention is not limited to this embodiment, but the structure is appropriately changed within the scope of satisfying the structure of claim 1. For example, the manufacturing method of the main body 2 of the flat nozzle 1 may be a method of pouring an indeterminate refractory material or a molten refractory material, and the slit-shaped nozzle hole 4 may be formed by a method other than machining. It may be divided into a plurality of pieces in the horizontal direction, provided downward at the lower end, or provided on the side dam side of the lower end.

Further, the mounting structure of the flat nozzle 1 of the present invention is not an essential part of the present invention, but, for example, the upper end surface of the flat nozzle 1 is provided with the support 15 and the movable support 1.
Tundish 9 using 6, bolts and nuts 17, etc.
The outer skin may be brought into contact with or fixed to the outer surface of the iron skin 10.

[0024]

According to the present invention, the nozzle main body is integrally formed, and the inner surface of the side wall is a vertical surface or an inclined surface that spreads upward, and the upper end thereof is an open end. The forming frame for forming can be easily pulled out, the conventional upper and lower assembly work can be omitted, and the manufacturing period of the nozzle body can be greatly shortened, and the manufacturing cost can be greatly reduced. Further, since the nozzle body is integrally formed and is strong, it is possible to stabilize the supply of the molten metal into the moving mold for a long time and stably maintain the continuous casting operation. Also, the effect of reducing the cost of refractories can be expected.

[Brief description of drawings]

1A and 1B are explanatory views showing an embodiment of the present invention, in which FIG. 1A is a partially cutaway sectional front view, FIG. 1B is a side sectional explanatory view of FIG. 1A, and FIG. FIG.

FIG. 2 is a partial cross-sectional front view showing an example of a flat nozzle mounting structure according to an embodiment of the present invention.

FIG. 3 is an elevational explanatory view showing an example of a conventional twin-drum type continuous casting device.

4A and 4B are explanatory views showing an example of a conventional flat nozzle, FIG. 4A is a partially cutaway sectional front view illustration, and FIG. 4B is a partially cutout sectional side view illustration of FIG. 4A.

[Explanation of Codes] 1 flat nozzle 2 nozzle body 2a, 2b drum-side sidewall inner surface 2c, 2d drum-side bottom portion inner surface 2e, 2f side weir-side sidewall inner surface 3 fireproof lid 4 slit-shaped nozzle hole 5 intermediate nozzle 5a, 5b intermediate nozzle hole 6 Intermediate Nozzle Insertion Hole 7 Melt Metal 8 Filter 9 Tundish 10 Skin Iron Shell 11 Refractory 12 Fireproof Block 13 Intermediate Nozzle Insertion Hole 14 Stopper 15 Support 16 Movable Support 17 Bolt Nut 18 Electric Heating Electrode a Inner Nozzle b Outer nozzle c Cast slab f Porous refractory d Meltable metal member e Molten metal p Hot water pool Ra, Rb Cooling drum Sa, Sb Side weir o Slit nozzle u pin h Nozzle body width t Nozzle body thickness

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[Procedure amendment]

[Submission date] October 5, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

In order to meet such a demand, for example, in the invention of Japanese Patent Laid-Open No. 63-203254 , a filter made of a porous refractory having slit-shaped nozzle holes o in the side wall of the cooling drum near the lower closed end. A flat nozzle including f and the fusible metal member d has been proposed.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

[0010]

In the present invention, since the inner surface of the side wall of the nozzle body is vertically or upwardly inclined and the upper end thereof is the open end, the mold for forming the inner surface of the side wall is manufactured at the time of manufacturing the nozzle body. Since it is easy to pull out and the nozzle body can be integrally formed, it is possible to omit the conventional assembly work of the upper part and the lower part, and it is possible to greatly shorten the nozzle manufacturing process and significantly reduce the manufacturing cost. Further, since the nozzle body is integrally formed and is strong, it is possible to stabilize the supply of the molten metal into the moving mold for a long period of time and stably maintain the continuous casting operation. Also, the effect of reducing the cost of refractories can be expected.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

FIG . 2 shows a state in which the flat nozzle 1 of the present invention configured as described above is fixed to the lower part of the tundish 9. A refractory 11 is lined inside the outer skin 10 of the tundish 9 at the bottom.
2, an intermediate nozzle insertion hole 13 is provided. The insertion hole 13 is an inclined hole whose diameter decreases downward, and penetrates the outer skin 10.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hatsumi Kirihara 3434 Shimada, Hikari City, Yamaguchi Prefecture Inside Nippon Steel Works, Ltd. Hikari Steel Works (72) Hideo Tsukiji, No. 1 Higashihama-cho, Hachiman Nishi-ku, Kitakyushu, Fukuoka No. 1 within Kurosaki Ceramics Co., Ltd. (72) Inventor Yukio Inoue 1 Kimitsu, Kimitsu-shi, Chiba Nippon Steel Corporation Kimitsu Works Service Center Kurosaki Ceramics Co., Ltd. Kimitsu Branch

Claims (1)

[Claims] 1. The nozzle body has a side wall inner surface that is a vertical surface or an inclined surface that spreads upward, the upper end of which is an open end, and a horizontal slit is formed in the lower portion of the nozzle body. A flat nozzle for continuous casting of wide and thin cast slabs, characterized in that a fireproof lid having an insertion hole formed therein is disposed.