JPS63278648A - Belt for metal strip continuous producing apparatus - Google Patents

Abstract

PURPOSE:To prevent cold shut and surface wrinkle and to cast a metal strip having excellent surface characteristic by continuously or interruptedly arranging recessed part and projecting part extending toward width direction or sloping direction on a running belt. CONSTITUTION:The multiple number of the projecting parts 1a and the recessed parts 1b are alternatively arranged at the constant interval on the belt 1. When the belt 1 having the projecting and recessed parts runs to the casting direction X, the projecting part 1a and the recessed part 1b are periodically abutted on the lower face of the fixed weir 6 and the fixed weir 6 is vibrated to the Y direction. Further, as the distance from the lower face of the fixed weir 6 to the belt 1 is periodically varied, the solidified material 15 developing as sticking on inner wall of the fixed weir 6 is heated and melted by molten metal in a pouring basin part 4. Further, the solidified material 15 sticking and developing on the inner wall of the fixed weir 6 is peeled by vibration of the fixed weir 6. The projecting and recessed parts 1a, 1b act to arrangement of solidified starting point toward width direction and prevent the development of the surface wrinkle on the solidified shell 10 and also give the solidified weir 6 the vibration and prevent the cold shut.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a belt used in an apparatus for manufacturing a metal ribbon by cooling and solidifying molten metal on a running belt.

[Conventional technology]

BACKGROUND ART Recently, a continuous casting method that directly produces a thin strip from molten metal such as molten steel, which has a thickness similar to the final shape and has a thickness of about the same size as the final shape, has been attracting attention. When using this method, the hot rolling process is not required or can be significantly simplified, and the process and equipment can be simplified.

One of these continuous casting methods is a belt method. In this method, for example, a pool is formed on a belt that runs endlessly, and the molten metal poured into the pool is cooled and solidified by heat removal through the belt, and the resulting shell is released as the belt runs. The molten metal is then sent out from the pool to produce metal ribbon. When using this belt method, the molten metal is cooled from one direction, and the surface opposite to the belt is open. Therefore, there are fewer restrictions on the arrangement of nozzles that supply molten metal from a container such as a tundish to a pool on the belt.

The inventors of the present invention have developed a casting device using this belt method in which the weir that partitions the side surface of the basin can be moved, and has filed an application for this as Japanese Patent Application No. 155247/1982.

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

In this device, a metal belt 1 is connected to a pair of Boo! J
2a and 2b have hooks and are designed to run on endless tracks. By holding one pulley 2a high, the endless track of the belt 1 is controlled by the pulley 2a.
It will rise towards.

A plurality of heat-resistant blocks 3 connected by chains or the like are arranged around the belt 1, and 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 sump 4 at the upper part where the belt 1 runs linearly. On the other hand, a fixed weir 6 is provided at the rear of the water reservoir 4. As a result, a trough portion 4 is formed that is open only in the direction in which the belt 1 moves.

Molten metal 8 is poured into this pool 4 from a pouring device 7.

The poured molten metal 8 is heated by a cooling device 9 disposed on the back side of the belt 1, cooled and solidified, and becomes a solidified shell 10. This solidified shell 10 is conveyed rightward in FIG. 4 as the belt 1 moves. Since heat continues to be removed during this transportation process, the solidified shell 10
grows into a thin ribbon 11 having a predetermined thickness, and is sent out from the pool 4.

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

[Problem that the invention seeks to solve]

In the sump 4 of this continuous casting apparatus, in addition to the formation and growth of the solidified shell 10 on the surface of the belt 1, solidification occurs in the portion that contacts the fixed weir 6. Figure 5 shows
This shows the solidification state of the molten metal in this part. That is, the heat retained in the molten metal in the pool 4 is dissipated even through the fixed weir 6. As a result, the coagulated material 15 adheres to the portion that contacts the fixed weir 6. This solidified material 15 grows over 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 running force of the belt 10 carrying out the coagulated shell 10 is applied to the coagulated material 15, and the coagulated material 15 is peeled off from the fixed weir 6. After the solidified material 15 has been peeled off, the solidified material 15 is attached again to the inner wall of the fixed weir 6. In this way, the solidified material 15 is intermittently peeled off, and this results in so-called cold shut, which appears as surface defects such as wrinkles and wave directions on the ribbon 11.

As a means for preventing defects caused by the peeling of the solidified material 15, in order to suppress heat radiation via the fixed weir 6,
It is conceivable to provide a refractory layer with good heat insulation on the inner surface of the fixed weir 6. However, even with this refractory lining, the heat dissipation cannot be completely eliminated, and the formation of coagulum 15 is still observed, making it impossible to prevent a cold shaft. Alternatively, a method of attaching a means for applying vibration to the fixed weir 6 may be considered, but in this case, it is necessary to separately arrange the means for applying vibration, making the configuration of the device complicated.

Furthermore, the solidified shell 10 generated in the water reservoir 4 is
The formation and growth rate differs depending on the surface condition of the material. For example, when using a belt 1 with a flat surface, the solidification start point 16 shown in FIG. It changes irregularly in the width direction of the plate, and this continues to form irregular surface wrinkles on the slab.

Therefore, the present invention improves the shape of the belt itself without requiring a separate vibration imparting means.
The purpose is to prevent the occurrence of cold shut and irregular surface wrinkles, and to produce a metal ribbon with excellent surface properties.

[Means for solving problems]

In order to achieve the purpose of the belt for a continuous manufacturing device for metal ribbon of the present invention, the metal ribbon is produced by cooling and solidifying molten metal poured into a pool provided on the running belt. It is used in a continuous casting apparatus for manufacturing, and is characterized by continuous or intermittently provided recesses and/or protrusions extending in the width direction or diagonal direction.

〔Example〕

Hereinafter, the features of the present invention will be specifically explained using examples with reference to the drawings.

FIG. 1 is a diagram illustrating the formation of a coagulated shell and a coagulated material when a pool portion is formed using the belt of the embodiment of the present invention. In FIG. 1, members corresponding to those in FIG. 5 are indicated by the same reference numerals.

The bell 1 of this example is provided with a large number of convex portions 1a and concave portions 1b alternately arranged at regular intervals. When this uneven belt 1 is run in the casting direction X, the convex portions 1a and the concave portions 1b periodically come into contact with the lower surface of the fixed weir 6. This causes the fixed weir 6 to vibrate in the direction Y perpendicular to the belt l. 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 deposited on the inner wall of the fixed weir 6 is heated by the molten metal in the sump 4 and remelted. This periodic change in distance, together with the vibration of the fixed weir 6, causes the solidified material 15 that adheres to the inner wall of the fixed weir 6 to
Peel off from the inner wall of the fixed weir 6 before it becomes too large.

In addition, the unevenness provided on the surface of the belt 1 has the effect of aligning the solidification start point 16 in the width direction, as shown in FIG.
Irregular surface wrinkles are prevented from occurring in the solidified shell 10 formed thereon. That is, the solidified 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 if necessary. During this rolling process, the metal ribbon is still in a high temperature and soft state, so only a small number of rolling blades are needed. Alternatively, the metal ribbon with the unevenness left can be used as a product. For example, by using these irregularities as a base for painting, the adhesion of paint is improved.

The convex portion 1a and the concave portion 1b are, as shown in FIG. 2(a),
It can be provided along the width direction of the belt 1.

Alternatively, as shown in FIG. 6(b), it may be provided in a state inclined with respect to the width direction.

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

In the example shown in FIG. 2A, continuous wavy convex portions 1a and concave portions 1b are provided on the surface of the belt 1. In the example shown in FIG. 2B, convex portions 1a are provided intermittently on the surface of the belt 1. In the example shown in FIG. 2C, the recess 1b is intermittently
It is placed on the surface. These irregularities also make it possible to impart vibration to the fixed weir 6 and prevent cold shafts, as in the example shown in FIG. 1.

In FIG. 3(a), the height from the concave portion 1b to the convex portion 1a is 0.1 to 2fflI11, and the adjacent convex portion 1a
It is preferable that the distance B is 40 strokes or less. If the height A is less than 0.1 ma+, the effect of forming the unevenness is weakened, and cold shut and irregular surface wrinkles are likely to occur. On the other hand, when the height A exceeds 2M, deep horizontal wrinkles occur in the obtained metal ribbon, and the pressure rolls cannot remove the horizontal wrinkles.

In the same sense, the height C of the convex portion 1a in FIG. 3(C) or the depth E of the concave portion 1b in FIG. 3(C) is 0.
．． It is preferable that the distance is 2 to 3 mm, and the distance between adjacent convex portions 1a or the distance F between adjacent concave portions 1b is 100 mm or less.

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

The belt 1 used was one in which the unevenness shown in FIG. 3(a) was continuously formed. In this belt 1, the height of the protrusions 18 is 0.3 mm, and the distance B between adjacent protrusions 18 is 1.2 mm.
A convex portion 1a and a concave portion 1b of mm are provided.

The water pool R4 has a common steel composition and the temperature is 1570℃.
of molten metal is injected at a flow rate of 240 kg/min, and the width is 250 kg/min.
A metal ribbon of RX7III1 was cast in a caster at a rate of 20 mm/min. At this time, no irregular shape change was observed in the bell). Furthermore, the obtained metal ribbon had no defects such as cracks or surface roughness caused by cold shut.

On the other hand, when flat bell) 1 was used, the flatness of the obtained metal ribbon was also poor. In addition, there are 2 lines/
Cold shafts occurred at a rate of 3m [Effects of the Invention] As explained above, according to the present invention, by using a belt with a surface having regular irregularities, it is possible to prevent the occurrence of cold shafts on fixed weirs. In addition to imparting vibration, it also disperses the stress applied to the belt. As a result, cracks and surface roughness caused by the cold shaft are prevented, and a metal ribbon with excellent shape characteristics is obtained.

Furthermore, since no large force is applied to the belt, the durability of the belt is also improved. Thus, according to the present invention, when
It becomes easier to implement the belt cast method.

[Brief explanation of drawings]

Fig. 1 is a diagram illustrating the state of the pool during casting using the belt of the embodiment of the present invention, Fig. 2 is a plan view of the belt with unevenness, and Fig. 3 is The shape of unevenness in another example is shown. On the other hand, FIG. 4 shows a continuous casting apparatus previously proposed by the present inventors, and FIG. 5 is a diagram illustrating the occurrence of cold shafts in the conventional apparatus. Patent Applicant Nippon Steel Co., Ltd. Representative Masu Kobori (and 2 others) Fig. 1 Fig. 2 (0) (b) Fig. 3 1 O/LJ group S: Naoki of mouth gtl F: Direct connection recess Distance between Fig. 4 1 Nijioyu (iζrN1 Fig. 5

Claims (1)

[Claims] 1. In a continuous casting device that manufactures metal ribbon by cooling and solidifying molten metal poured into a pool provided on a running belt, recesses and/or Alternatively, a belt for continuous production of metal ribbon, characterized in that the convex portions are provided continuously or intermittently.