JPS6015052A - Continuous casting device of thin plate - Google Patents

Abstract

PURPOSE:To provide a titled device which eliminates seizure and overcooled parts and to roll a molten metal to a thin plate having a good shape in continuous casting of the thin plate in which the molten metal is solidified on the surface by a precooled casting mold and is cold rolled by oscillating vertically the precooled casting mold and suppressing the solidification at both ends by heating. CONSTITUTION:A molten metal 7 flowing downward from a tundish 6 enters a precooled casting mold 5 from a vessel 3 for reserving the molten metal and is solidified to have a shell on the surface by a water-cooling mechanism 11 then the molten metal is conducted to cooling mold rolls 1. The formed shell saggs smoothly without seizure by the vertical oscillation of the mold 5 and the growth of the shell by the overcooling at the ends is prevented by heaters 12 at both ends. The surface-solidified metal entering the rolls 1 in this state is rolled to a thin plate having a good surface and a good end shape without leakage and said thin plate is drawn by said rolls.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for directly and continuously casting thin plates from molten metal, particularly molten steel.

In continuous casting of molten steel, proposals have been made to manufacture thin plates directly by casting instead of conventional thick slabs. For example, an invention was published in JP-A-55-7 that attempted to directly manufacture thin plates from molten steel using cooled twin rolls as molds.
No. 5862 and Japanese Unexamined Patent Publication No. 58-32548. These are made by placing a pair of cooled casting rolls that rotate in opposite directions horizontally in parallel with a predetermined gap between them, and continuously extracting the thin plate slabs downward through this gap. Although continuous casting is intended, the rolls cannot rotate unless a gap is formed between the rotating roll and the non-rotating molten metal holding container located above it. Therefore, measures must be taken to prevent hot water from entering this gap.

The overall surface quality of the formed slab deteriorates, and in particular, defects in shape occur at both edges of the thin slab. However, these publications do not disclose specific solutions to avoid this problem. The present invention has a method in which a pair of cooled casting rolls rotating in opposite directions are arranged horizontally in parallel with a predetermined gap, and the thin slab is continuously extracted downward through this gap. In a continuous thin plate casting machine. This was done to solve the problems of deterioration of the surface quality of slabs and poor shape of both edges of thin slabs.

This problem can be avoided at its root by cooling the molten metal to such an extent that it is no longer in a fluid state just before it is cast into such casting rolls.

In other words, in the present invention, a pair of cooled casting rolls rotating in opposite directions are arranged horizontally in parallel with a predetermined gap, and the thin slab is continuously extracted downward through this gap. In the thin plate continuous casting apparatus, a mold for forming a plate-like intermediate body having a thickness larger than the slab drawn out from the gap between the casting rolls is placed such that the plate-like intermediate body coming out from the mold is sandwiched in the gap. , a device for injecting molten metal into the mold is placed above the casting roll, and a device for injecting molten metal into the mold is installed above the mold, and the mold is installed via a mold vibrating device that applies vertical vibration. For troublesome surfaces, use cooling means.

The present invention also provides a continuous thin plate casting apparatus characterized in that heating means are provided on both sides of the casting surface of the mold.

The details of the present invention will be specifically explained below with reference to the drawings.

Fig. 1 is a perspective view showing the appearance of the main parts of the apparatus of the present invention, in which a pair of cooled large diameter casting rolls la and lb, which rotate synchronously in opposite directions, are used to form a thin slab of slab thickness. A device is shown in which the rolls la and lb are arranged horizontally in parallel with a corresponding gap, and the thin slab 2 is continuously extracted downward from the gap between the rolls la and lb.

3 is a hot water reservoir, and hot water is injected into this hot water reservoir 3 through a nozzle 4 from a tandesosh above. In the apparatus of the present invention, the hot water in the hot water reservoir 3 is poured into the casting rolls la, 1.
A pre-cooling device (herein referred to as the mold 5) is installed before the hot water is poured into the casting mold 5, and while passing through this, the hot water is cooled to a point where it does not self-flow, and then it is poured into the casting roll. so that it is sent to la and lb.

FIG. 2 shows this state in cross-section, and shows the hot water tank 3.
The nozzle 4 from the tandesh 6 located above the
The hot water 7 injected through the mold 5 is pre-cooled in the mold 5, and after passing through the mold 5, the hot water 7 no longer flows by itself and is sandwiched between the casting rolls la and lb.

It is rolled and cast to the desired thickness. By cooling the casting rolls to a level where they do not self-flow, the casting rolls la,'
A free space can be provided between lb and the mold 5,
The casting rolls 1a+lb can be moved freely without the problem of contact with the non-rotating bodies above them, and the problem of pouring hot water into this free space is avoided.

In the apparatus of the present invention, the mold that provides such a pre-cooling effect is configured to form a plate-like intermediate body that is thicker and thicker than the finished thin plate slab.

This mold is centrifuged through a mold vibration device that gives vertical vibration to the mold, and a cooling means is installed to take care of the casting surface of this mold.
Further, heating means are provided on both sides of the casting surface of this mold.

To explain this in detail according to the drawings, as shown in Fig. 3, this mold 5 has an opening 8 that penetrates vertically in the form of a slit, and the width of this slit (which is the thickness of the plate-shaped intermediate) t is It is several times larger than the thickness of the finished slab. Both short sides 9 and both sides 10 on the inner surface of this opening 8 form the mold surface, and the surface near the center of the two sides 10 is made of metal such as a copper plate or a steel plate with a water cooling mechanism 11 behind it. - consists of 2
Both sides of both shop sides lO and both short sides 9 are.

It has a refractory 13 surface with a heater 12 embedded therein. This heater 12 is as shown in FIG.

It is arranged in the refractory 13 so as to occupy most of the height of the mold 5. As a result, when the molten metal poured into the mold 5 passes through the mold 5, it exits the mold 5 in the form of a plate-shaped intermediate having a thickness greater than that of the finished sheet slab. .

The wide surface side of this plate-shaped intermediate body is strongly cooled by the water cooling mechanism 11, and overcooling is prevented by the heaters 12 on both sides of the plate-shaped intermediate body, so that the whole plate-shaped intermediate body coming out of the mold 5 is uniformly pre-cooled. Even if it moves downward away from the mold 5, the plate-like intermediate formed by the mold 5 maintains its shape as it is and is sandwiched between the casting rolls 1a and 1b. Therefore, casting roll la, special weirs and dams that block the flow of
It is not necessary to provide it directly above lb. On the other hand, as shown in FIG. 2, this mold 5 is firmly set via a vibration applying device 15, and minute vibrations are applied in the vertical direction by this vibration applying device. The amplitude and frequency of this vibration are set to prevent seizure between the solidified shell and the surface of the mold.

Although not shown in Figure 2, casting rolls 1a and 11
] both have a water-cooling mechanism inside, and the plate-shaped intermediate that has advanced to the roll gap is cooled here while being cast and rolled into a thin plate.

As described above, according to the apparatus of the present invention, in the direct casting of a thin plate from molten steel using a cooling roll, there is no need to insert hot water between the rotating roll and the non-rotating body thereon, so that the hot water is not poured between the rotating roll and the non-rotating body thereon. The problem of deterioration of the surface properties of the slab due to the insertion of the cast slab and the problem of poor shape of both edges of the slab are simultaneously completely avoided, and direct continuous casting of high-quality thin plates becomes possible.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view showing an example of the device of the present invention, FIG. 2 is a schematic vertical sectional view not showing an example of the device of the present invention, and FIG.
FIG. 4 is a schematic sectional view taken along the line Tt/-TV in FIG. 3; 1. Cooling casting roll, 2. Thin sheet slab. 3. Water reservoir, 4. Injection nozzle. 5.Mold (pre-cooling device), 6.Tandeshuma...hot water, 8.Slit-shaped opening. 9...Short side, 10...Wide surface, 11...Water cooling mechanism. 12...Heater, 15...Vibration imparting device. Applicant: Nisshin Steel Co., Ltd.□゛,-1 Agent: Patent attorney Kenji Wada,,! L! Nia, ji

Claims (1)

[Claims] A pair of cooled casting rolls that rotate in opposite directions are arranged horizontally in parallel with a predetermined gap, and the thin slab is continuously extracted downward through this gap. In a thin plate continuous casting machine. A mold for forming a plate-shaped intermediate body that is thicker than the slab pulled out from the gap between the casting rolls is placed above the casting rolls so that the plate-shaped intermediate body coming out of the mold is sandwiched in the gap. And in this mold? 8? A device for injecting & is installed further above this mold, and the mold is installed via a mold vibration device that applies vertical vibration,
A continuous thin plate casting apparatus characterized in that a cooling means is provided on the casting surface of the mold, and heating means are provided on both sides of the casting surface of the mold.