JPH0763814B2 - Belt for single belt continuous casting machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a running metal belt, a side pool and a rear wall provided on the metal belt, and a molten metal pool formed on the surface of the metal belt. The present invention relates to a metal belt used in a single-belt continuous casting device, which pours a molten metal and solidifies the molten metal by removing heat through a metal belt to produce a thin metal strip.

[Conventional technology]

Recently, from molten metal such as molten steel, several mm to several tens, which is close to the final shape
Attention has been paid to a continuous casting method for directly producing a ribbon having a thickness of about mm. According to this method, the hot rolling step is not necessary or can be greatly simplified, and the steps and equipment can be simplified.

One of the continuous casting methods is a single belt method.
In this method, for example, a molten metal pool formed on an endless running belt is cooled and solidified by removing heat from the molten metal poured through the belt, and the generated shell is accompanied by the running of the belt. The metal ribbon is manufactured by sending it out from the pool. In this belt method, the molten metal is cooled from one direction and the surface opposite to the belt is open. Therefore, there are less restrictions on the arrangement of the nozzles that supply the molten metal from the container such as a tundish to the molten metal pool on the belt.

The present inventors have developed a casting apparatus in which the weir that partitions the side surface of the molten metal pool can be moved in this single belt system, and filed as Japanese Patent Application No. 60-155247.

FIG. 4 shows the belt type apparatus proposed in this prior application.

In this device, a metal belt 1 is provided with a pair of pulleys 2
It is hung on a and 2b and runs on an endless track. By holding one pulley 2a high, the endless track of the belt 1 rises toward the pulley 2a. Around the belt 1, a plurality of heat resistant blocks 3 connected by a chain or the like are arranged,
These heat resistant blocks 3 move in synchronization with the running of the belt 1.

The heat-resistant block 3 serves as a side weir 5 that partitions the side of the pool 4 at the upper portion where the belt 1 travels in a straight line. On the other hand, a fixed weir 6 is provided behind the hot water pool 4. As a result, the basin 4 is formed in which only the traveling direction of the belt 1 is open. Molten metal 8 is poured into the pool 4 from a pouring device 7.

The molten metal 8 poured is removed from heat by a cooling device 9 arranged on the back surface of the belt 1, cooled and solidified into a solidified shell 10. The solidified shell 10 is conveyed rightward in FIG. 4 as the belt 1 moves. Since the heat removal is continued in the course of this transportation, the solidified shell 10 grows into a thin strip 11 having a predetermined thickness and is sent out from the molten metal pool 4.

This thin strip 11 is then rolled by a pressure roll 12 to a target plate thickness, and is wound up as a thin plate coil 14 by a winding device 13.

[Problems to be solved by the invention]

In the basin 4 of this continuous casting apparatus, solidification occurs at the portion in contact with the fixed weir 6 in addition to the generation and growth of the solidified shell 10 on the surface of the belt 1. FIG. 5 shows the solidified state of the molten metal in this portion. That is, the molten metal of the molten metal pool 4 dissipates its heat even through the fixed weir 6. As a result, the solidified material is formed on the portion contacting the fixed weir 6.
15 is attached. The solidified material 15 grows with the lapse of time and becomes continuous with the solidified shell 10 which is the original purpose. When the solidified material 15 continues to the solidified shell 10, the solidified shell 10
The running force of the belt 1 carrying out 10 is applied to the solidified material 15, and the solidified material 15 is separated from the fixed dam 6. The solidified material 15 adheres again to the inner wall of the fixed weir 6 after the solidified material 15 is peeled off. In this way, the solidified material 15 is peeled off intermittently, which causes so-called cold shut, which appears as surface defects such as wrinkles and waves in the ribbon 11.

As a means for preventing the defect caused by the separation of the solidified material 15, it is conceivable to provide a refractory layer having good heat insulating property on the inner surface of the fixed weir 6 in order to suppress heat radiation through the fixed weir 6. . However, even with this refractory lining,
It is not possible to completely eliminate the heat dissipation, the formation of the solidified material 15 is still observed, and cold shut cannot be prevented. Also, a method of additionally providing a means for applying vibration to the fixed weir 6 is conceivable, but in this case it is necessary to separately arrange the vibration applying means, which complicates the configuration of the apparatus.

The solidification shell 10 produced in the basin 4 has different production / growth rates depending on the surface condition of the belt 1. For example, when using the belt 1 with a flat surface,
The solidification starting point 16 shown in the figure changes irregularly in the sheet width direction due to the uncontrollable flow of molten steel, the thermal conductivity between the belt and the molten steel, and the difference in the wettability between the belt and the molten steel. Irregular surface wrinkles are formed.

Therefore, the present invention improves the shape of the belt itself without arranging a separate vibration imparting means,
The object is to prevent the generation of cold shuts and irregular surface wrinkles, and to produce a metal ribbon having excellent surface properties.

[Means for solving problems]

The belt for a single-belt continuous casting device of the present invention is, in order to achieve the object thereof, a running metal belt, and a pool of water formed on a surface of the metal belt by a side dam and a rear dam provided on the metal belt. A belt used in a single-belt continuous casting device, in which molten metal is poured into a part and the molten metal is solidified by removing heat through a metal belt to produce a thin metal strip. It is characterized in that recesses and / or projections extending in the direction are provided continuously or intermittently.

〔Example〕

Hereinafter, the features of the present invention will be specifically described by way of examples with reference to the drawings.

FIG. 1 is a diagram for explaining the state of formation of a solidified shell and a solidified product when a molten metal pool is formed using the belt of the embodiment of the present invention. In FIG. 1, members and the like corresponding to FIG. 5 are designated by the same reference numerals.

The belt 1 of this example is provided with a large number of convex portions 1a and concave portions 1b alternately at regular intervals. This uneven belt 1
When traveling in the casting direction X, the convex portions 1a and the concave portions 1b periodically contact the lower surface of the fixed weir 6. As a result, the fixed weir 6 vibrates in the direction Y perpendicular to the belt 1. Further, as the distance from the lower surface of the fixed weir 6 to the surface of the belt 1 changes periodically, the solidified material 15 attached and formed on the inner wall of the fixed weir 6 is heated by the molten metal in the basin 4 and melted again. This periodic change in the distance, coupled with the vibration of the fixed weir 6, causes the solidified matter 15 adhered and formed on the inner wall of the fixed weir 6 to separate from the inner wall of the fixed weir 6 before it becomes too large.

Further, as shown in FIG. 5, the unevenness provided on the surface of the belt 1 acts to align the solidification starting points 16 in the width direction, and irregular surface wrinkles are generated on the solidification shell 10 formed thereon. Is prevented. That is, in the solidification shell 10,
There are only regular irregularities corresponding to the irregularities on the surface of the belt 1. Since these irregularities are sufficiently small, they can be removed by pressing down with the pressure roll 12 as needed. Since the metal ribbon during this rolling is still in a high temperature and soft state, a small rolling force is required. Alternatively, the metal ribbon with the concavities and convexities left can be used as a product. For example, the use of these irregularities as a base for painting improves the adhesion of the paint.

The convex portion 1a and the concave portion 1b can be provided along the width direction of the belt 1, as shown in FIG. Alternatively, as shown in FIG. 7B, the light emitting device can be provided in a state of being inclined with respect to the width direction.

In the example of FIG. 1, the convex portions 1a and the concave portions 1b are alternately and intermittently provided. However, the unevenness provided on the surface of the belt 1 is not limited to this example, and may be various convex portions 1a or concave portions 1b as shown in FIG. 3, for example.

In the example of FIG. 7A, the continuous wavy convex portion 1a and concave portion 1b are formed.
Is provided on the surface of the belt 1. In the example of FIG. 2B, the convex portions 1a are intermittently provided on the surface of the belt 1. Further, in the example of FIG. 7C, the recesses 1b are intermittently provided on the surface of the belt 1. Even with these irregularities, as in the example of FIG. 1, it is possible to apply vibration to the fixed dam 6 and prevent cold shut.

In FIG. 3 (a), the height A from the concave portion 1b to the convex portion 1a
Is preferably 0.1 to 2 mm, and the distance B between the adjacent convex portions 1a is preferably 40 mm or less. If the height A is less than 0.1 mm, the effect of unevenness formation is weakened, and cold shut and irregular surface wrinkles are likely to occur. On the other hand, height A is 2mm
When it exceeds the above range, a deep wrinkle is generated in the obtained metal ribbon, and the wrinkle cannot be removed by the pressure roll. In the same sense, the convex portion 1a in FIG. 3 (b)
Height C or the depth E of the recess 1b in FIG. 3 (c) is 0.
It is preferable that the distance D is 2 to 3 mm and the distance D between the adjacent convex portions 1a or the distance F between the adjacent concave portions 1b is 100 mm or less.

Next, specific operating conditions and properties of the obtained metal ribbon will be shown.

As the belt 1, a belt having the concavities and convexities shown in FIG. 3 (a) formed continuously is used. This belt 1 has a convex portion 1a having an unevenness height A of 0.3 mm and a distance B between adjacent convex portions 1a of 1.2 mm.
And a recess 1b. Then, a molten metal having a normal steel composition and a temperature of 1570 ° C. was poured into the pool 4 at a flow rate of 240 kg / min, and a metal strip having a width of 250 mm and a wall thickness of 7 mm was cast at a speed of 20 m / min. At this time, no irregular shape change was observed on the belt 1. In addition, the obtained metal ribbon had no defects such as cracks and surface roughness due to cold shut.

On the other hand, when the flat belt 1 was used, the flatness of the obtained metal ribbon was also poor. Also, 2/3 on the surface
Cold shut was generated at a rate of m [Effect of the invention] As described above, in the present invention, a belt having a surface provided with regular unevenness, which is used in the single belt type continuous casting apparatus. By using, the vibration is applied to the fixed weir and the stress applied to the belt is dispersed. As a result, cracks and surface roughness due to cold shut are prevented, and a metal ribbon with excellent shape characteristics can be obtained. Also, since no great force acts on the belt,
The durability of the belt is also improved. As described above, according to the present invention, it is easy to carry out the single belt type continuous casting method.

[Brief description of drawings]

FIG. 1 is a view for explaining the situation of the molten metal pool portion when casting is performed using the belt of the embodiment of the present invention, FIG. 2 is a plan view of a belt provided with irregularities, and FIG. 3 is The shape of the unevenness in another example is shown. On the other hand, FIG. 4 shows the single-belt type continuous casting apparatus previously proposed by the present inventors, and FIG. 5 is a diagram explaining that cold shut occurs in the conventional apparatus.

Claims (1)

[Claims] 1. A molten metal is poured into a molten metal pool formed on the surface of the metal belt by a running metal belt and side and rear weirs provided on the metal belt, and the molten metal is drained through the metal belt. In a belt used in a single belt type continuous casting device for producing a metal ribbon by solidifying a molten metal by heat, a concave portion and / or a convex portion extending in a width direction or an oblique direction is provided continuously or intermittently. A belt for a single-belt type continuous casting device, which is characterized in that