JP2636624B2 - Apparatus for sealing molten metal on chill roll - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for sealing molten metal on a cooling roll, and more particularly to a sealing apparatus in which a ceramic fiber bar felt and a metal plate are interposed between the cooling roll and a casting nozzle.

[0002]

2. Description of the Related Art Conventionally, in continuous casting of thin sheets, it has been important to seal the molten metal between a rotating cooling roll and a casting nozzle, and there have been many proposals for a sealing device and mechanism therefor. . For example, JP-A-63-1010
No. 53 discloses an example in which a felt made of elastic ceramic fiber is provided on the casting nozzle side.

However, the cushioning material according to this proposal is insufficient in strength when actually used, and may be broken during use, and may be caught in a product to cause a push flaw. As a solution to such a defect, Japanese Patent Application Laid-Open No. 2-117749 discloses a method of removing a defect such as an indentation flaw by using a cloth material of an inorganic material as a sealing material on a sliding surface such as a casting nozzle for a cooling roll. It has been proposed to use.

[0004] However, even with this material, it is practically difficult to obtain a very thin and heat-resistant material that can withstand the frictional force between the roll and the pouring nozzle and that is used for sealing.
Moreover, they are expensive, and since they are consumables, the rise in product costs is unavoidable. In addition, woven fabric materials that meet the purpose are sometimes found, but in order to install them so that they do not protrude into the casting space formed by the casting nozzle and roll, cutting processing according to the actual product is necessary, and the end face is cut by cutting. Loses its strength and is broken by the frictional force with the rolls, which causes hot water leakage and push-in flaws.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an effective sealing means for preventing a molten metal from leaking between a cooling roll and a pouring nozzle in a continuous casting method of a thin plate. is there.

[0006]

Means for Solving the Problems Here, the present inventors have
Various studies were made to solve such a problem, and the following findings were obtained. The sealing of the molten metal is basically performed by using an elastic ceramic fiber felt to sufficiently prevent the molten metal from leaking. The insufficient strength of the ceramic fiber felt can be solved by protecting it with a metal plate.

[0007] The hardness of the metal plate used for reinforcement is equal to or less than the surface hardness of the cooling roll so as not to damage the cooling roll. The disposition relationship between the metal plate and the ceramic fiber felt is that the metal plate is set back from the casting space by 1 to 5 mm.
The quality of the cast sheet is ensured. The portion of the ceramic fiber felt that is in contact with the molten metal is protected by the ceramic bond, thereby avoiding the loss of the felt during casting and exerting the reinforcing effect of the ceramic fiber felt not protected by the metal plate.

Accordingly, the gist of the present invention is to provide a device for manufacturing a thin metal plate by rapidly solidifying molten metal on the peripheral surface of a rotating cooling roll. And between the ceramic fiber felt layer and the cooling roll, the tip is 1 to 5 from the tip of the casting nozzle.
A molten metal sealing device characterized by interposing a thin metal plate so as to retreat by mm.

According to a preferred aspect of the present invention, the surface of the ceramic fiber felt layer which contacts the molten metal may be covered with a ceramic bond layer. Preferably, the metal plate has a surface hardness equal to or lower than the surface hardness of the rotating cooling roll.

[0010]

Next, the operation of the present invention will be described. 1 to 3 are cross-sectional views illustrating an embodiment of the method according to the present invention. FIG. 1 is a plan view, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. FIG. As can be seen from FIG. 1, the tip of the tundish 10 has a casting nozzle bottom 12
b and a casting nozzle side weir 12a are integrally formed, and a casting nozzle 12 is formed.The tip of the casting nozzle bottom 12b and the casting nozzle side weir are in contact with the cooling rolls 14 to define the casting space and to be injected. To prevent molten metal (not shown) from overflowing.

Although the molten metal leaks during the continuous casting occurs at the contact surface between the side weir 12a and the cooling roll 14 and the contact surface between the casting nozzle bottom 12b and the cooling roll 14, the problem usually arises from the casting nozzle bottom 12b. This is a leak of hot water at the contact surface between the cooling roller 14 and the cooling roller 14.

FIG. 2 shows a ceramic fiber felt layer.
It is a diagram showing the arrangement of 20 and the metal plate 22 with respect to the nozzle 12,
Ceramic fiber felt layer 20 is nozzle bottom 12b
The metal plate 30 is fixed to the lower part of the tundish 10 and advances to the nozzle side, and is formed between the ceramic fiber felt layer 20 and the cooling roll 14. It is located between them.

FIG. 3 shows a sectional structure of the casting nozzle 12. A ceramic fiber felt layer 20 is adhered to a lower surface of a nozzle tip 24 which is usually made of a refractory. Is composed. The ceramic fiber felt layer 20 does not come into direct contact with the molten metal, and a ceramic bond layer 28 is provided at the tip thereof. In the drawing, there is a space between the ceramic fiber felt layer 20 and the cooling roll 14, but in practice, this portion is sealed in a state of contact, and continuous casting is performed.

According to the present invention, a metal plate 30 is provided between the ceramic fiber felt layer 20 and the cooling roll 14.
The tip is disposed so as to be located at a tip of a casting nozzle, in this case, at a position retracted by 1 to 5 mm from the tip of the ceramic bond layer 28.

The ceramic fiber felt used in the present invention is an alumina fiber, a silicon carbide fiber, a high silica glass fiber, or the like, and may be, for example, commercially available under the trade name "Arsen". The ceramic bond is obtained by dispersing particles of alumina, silica, ZrO ₂ or the like in a binder, and may be commercially available under the trade name “Sumiceram”.

The metal plate is not particularly limited as long as it has a surface hardness equal to or less than the surface hardness of the cooling roll, but generally, a material having excellent heat resistance, such as a stainless steel plate, is preferable. Generally, a plate thickness of about 0.05 to 0.3 mm is sufficient. As described above, by interposing the ceramic fiber felt layer and the metal plate between the casting nozzle and the cooling roll according to the present invention, the following synergistic effects are produced.

In the thin sheet continuous casting method, the oxide of the molten metal adheres to the casting roll, but the heat transfer coefficient changes depending on the state of the adhesion, and the thickness of the slab may become uneven or cracked. For this reason, various attempts have been made to make the attached matter uniform. For example, Japanese Patent Application Laid-Open No. 3-118944 proposes not to simply scrape off the deposits but to form a uniform thin film, but it is also possible to use a metal plate as in the present invention. Since the metal plate is pressed against the surface of the cooling roll, there is an effect that the oxide scale is leveled. As a result, a slab having a uniform thickness can be manufactured, and defects such as cracks, wrinkles, and depressions can be prevented.

[0018]

EXAMPLES The operation and effects of the present invention will be described more specifically with reference to examples. In this example, continuous casting of SUS 304 was performed for 5 minutes using the apparatus shown in FIGS. The cooling roll is made of stainless steel and has an outer diameter of 600 mm and a surface hardness of Hv
180, two types of stainless steel plates (0.1 mm thick) with different surface hardness were used as the metal plates. The results are summarized in Table 1.

[0019]

[Table 1]

[0020]

As described above, according to the present invention, the metal plate is used for reinforcing the ceramic fiber felt layer and for smoothing the deposit on the cooling roll. The effect of using
The following points can be mentioned. In the conventional example, it was necessary to cut the inorganic sealing material on site so that the inorganic sealing material did not protrude into the casting space, that is, did not protrude beyond the tip of the casting nozzle, according to the actual dimensions. This is not necessary because the metal plate used in (1) can be mounted 1-5 mm away from the casting space. The metal plate processed in the factory can be used as it is. For this reason, the setup time required for the attachment can be reduced, and the operability is improved. The metal plate is a general material, and the material cost is low. Reuse is possible, and the total cost can be significantly reduced. The synergistic action with the ceramic fiber felt layer provides a sufficient sealing effect and can further extend the life. Smoothness of the deposits on the cooling roll can also be effectively performed, and the quality of the cast slab can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view of an apparatus for performing a method according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

[Explanation of symbols]

10: Tundish 12: Nozzle 12b: Bottom of casting nozzle 14: Cooling roll 12a: Side dam 20: Ceramic fiber felt layer 28: Ceramic bond layer 30: Metal plate

Claims (3)

(57) [Claims] 1. An apparatus for manufacturing a thin metal sheet by rapidly solidifying a molten metal on a peripheral surface of a rotating cooling roll, wherein a ceramic fiber felt layer is disposed on a surface of the casting nozzle which is in contact with the cooling roll, and the ceramic fiber felt layer is provided. A molten metal sealing device, wherein a thin metal plate is interposed between the casting nozzle and the cooling roll so that the tip is retracted by 1 to 5 mm from the tip of the casting nozzle. 2. A surface of the ceramic fiber felt layer in contact with a molten metal is covered with a ceramic bond layer.
An apparatus according to claim 1. 3. The apparatus according to claim 1, wherein the metal plate has a surface hardness equal to or less than a surface hardness of the rotating cooling roll.