JPS6216851A - Device for casting thin sheet - Google Patents

Abstract

PURPOSE:To obtain a thin sheet having an excellent surface characteristic and uniform thickness by providing a rear stationary gate and movable side gate for inclining a casting direction so as to raise and forming a pouring basin for a molten metal on a metallic belt. CONSTITUTION:The metallic belt 1 is driven by a pulley 2 and the side gate 4 is also driven in synchronization with the belt 1. The molten metal is poured from a pouring device 6 into the space formed by the rear stationary gate 5 and the movable side gate 4 on the surface of the inclined belt 1 to form the pouring basin 8. The rear surface of the belt 1 is cooled with water by a cooler 3 in the process of casting which begins from the gate 5. The solidification starts on the surface of the belt 1 past the bottom surface of the gate 5 in the lower part of the basin 8. A solidified layer develops under the molten metal surface and is extracted diagonally upward as a thin sheet. The solidification starts right after the gate 5 on the belt 1 surface. The solidification initiation point is thus made uniform and the formation of cold shut and double surfaces, the ununiform thickness of the solidified layer, etc. arising from the ununiform solidification start point are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a single-sided solidification continuous casting apparatus for producing sheet metal, such as steel strip.

BACKGROUND OF THE INVENTION Conventionally, in order to produce a thin metal plate, such as a thin steel plate, a steel ingot is bloomed and rolled to obtain a slab with a thickness of 200 to 250 m+s.
This slab is hot-rolled in a hot-strength 1-roll mill, or the molten steel is continuously rolled for 2 tons to obtain a slab, which is then hot-rolled.

However, since these conventional techniques require energy to heat a large-scale hot strip mill or slab, it is desired to develop a technique for directly obtaining thin plates by wbcPI production of molten steel.

Conventionally, when continuously casting molten steel, a method has generally been used in which the molten steel is injected into a mold, solidified around the cross section, and then pulled out downward. However, with this method, it is difficult to obtain slabs with a thickness of several tens of meters or less due to the relationship between the diameter of the nozzle that injects molten steel into the mold and the cross-sectional dimensions of the mold.■ Slab slabs and mold inner wall surface Due to the friction between
It is difficult to raise it above m/win, and 2m/ll.
If the thickness exceeds 1 inch, there is a risk that the solidified shell will break and a flow of molten steel will blow out (breakout).

In order to solve these problems in the conventional continuous casting process and provide an efficient manufacturing method by continuous casting of thin plates and an apparatus therefor, the applicant previously filed a Japanese Patent Application No. 58-188.
In No. 882, a method and apparatus for manufacturing thin metal sheets by single-sided casting was proposed.

That is, this method and apparatus is a method of pouring molten steel onto a flat plate forming an inclined endless track to cast a thin steel plate, and in which the casting direction and the method of pouring molten steel flow are reversed, that is, the flat plate forming an endless track is cast on an inclined plane. A method in which molten steel is poured onto a flat plate while moving upward, and the lower end of the molten steel (molten metal) flow on the inclined moving flat plate is self-retained by the surface tension of the molten steel, and a driving wheel. a belt mechanism driven by a belt mechanism having an endless track and an inclined plane; a means for supplying molten metal downward onto the inclined belt plane;
This is a continuous casting device for molten metal, which includes a device for extracting slabs above the slope, and a device for driving a belt upwards on the slope via a drive wheel.

With this technology, steel plates with a thickness of 2 to 20 mm, for example, can be produced by continuous casting. According to this technology, molten steel (molten metal) solidifies on a track plane that is inclined and moves upward, and the extraction speed of the solidified shell (slab) and the moving speed of the track plane (belt) are synchronized. If so,
Since breakout due to friction between the belt surface and the slab does not occur, the casting speed can be dramatically increased.

In addition, since it is one-sided solidification, the bottom surface of the slab is in contact with the belt surface during casting, but the top surface is in contact with the molten steel or the atmosphere, and since there is no space constraint such as a mold, the molten steel is transferred from the tundish to the molten steel. There are no problems with the nozzle arrangement for supplying the water.

The present applicant has further improved this technique by disposing a fixed weir extending in the width direction of the metal belt at the lower end of the molten metal injection flow so as to be in elastic contact with the metal belt. The patent application No. 59-120 describes a process for forming a molten metal pool in a metal belt to solve the problem of wrinkle formation in slabs caused by irregularities in the planar shape of the tip of the molten metal injection flow on a metal belt.
It was proposed in No. 588.

However, in these techniques, the side bases that regulate the side edges of the slab are fixed. In a single-sided solidification type thin plate continuous casting apparatus having such a fixed side base,
The slab during solidification is restrained by the side base, allowing smooth movement of the slab (
Extraction) was obstructed, and not only did the power required to drive the metal belt become excessive, but there were also problems such as the slab being cut if it was forcibly pulled out.

Problems to be Solved by the Invention The present invention solves the problems in the prior art described above, and furthermore makes it possible to obtain a thin metal sheet having a length of 714 m, excellent surface quality without double skin, and a uniform thickness. The purpose of this project was to provide a single-sided solidification type thin plate continuous casting equipment.

Means for Solving the Problems The configuration of the present invention includes an endless metal belt that is inclined so that the casting direction is upward, and a cooling device is attached to the back side;
It has a rear fixed weir for forming a puddle of molten metal on the metal belt, and a side base that moves in synchronization with the metal belt, and the molten metal injection position is separated from the rear fixed weir by a predetermined distance. The thin plate casting apparatus is characterized in that it is located at

The present invention will be explained below by taking the embodiment shown in FIG. 1 as an example.

In Figure 1, (1) is a metal belt and a pulley (
2) and forms an endless track.

(3) is a cooling device during the casting process.

The metal belt (1) is cooled from its back side. (4) is
The side base is composed of a chain of heat-resistant blocks wound around a not-shown tin rocket wheel to form an endless track, and moves in synchronization with the metal belt (1).

(5) is a rear fixed weir, which is provided so as to extend in the width direction of the metal belt, and at least a part of its lower surface is in contact with the upper surface of the metal belt, and is elastically pressed against the upper surface of the metal belt by, for example, a spring. be done.

(6) is an injection device, from the rear fixed weir (5),
The injection flow (7) is arranged at a predetermined distance in the PIJ:11 direction. (8) is a hot water reservoir, with a rear fixed weir (5) on the surface of the metal belt (1).
The space surrounded by the movable side base (4) is formed by molten metal supplied from the injection device (6).

(9) is a solidified thin plate, that is, a slab, and a metal belt (
1) is extracted from the pool (8) above the slope formed by the hot water pool (8), rolled or surface-shaped by the rolling rolls (10), and wound by the winding device (It) to form a thin plate (strip) coil (12). ).

Function The function of the thin plate casting apparatus of the present invention will be explained below.

The metal belt (1) is driven by a pulley (2) at a speed of, for example, 70 m/win. At the same time, the side base (4) is also driven by a sprocket wheel (not shown) in synchronization with the metal belt (1).

Molten metal, such as molten steel, is injected from an injection device (6) into the space formed on the inclined surface of the metal belt (1) by the fixed rear weir (5) and the movable side base (4),
A trough (8) is formed.

The back side of the metal bell (1) is water-cooled by a cooling device (3) during the casting process starting from the rear fixed weir (5).

So, 71! At the bottom of the pool (8), the rear fixed weir (5)
Solidification begins on the metal belt (1) surface, a solidified layer develops below the surface, and is extracted as a thin plate (slab) above the slope by the metal belt (1).

In this invention, in order to obtain a thin plate with excellent surface properties (no wrinkles, double skin, etc.) and uniform thickness by continuous casting with high productivity, the position of the injection stream (7) is determined. is important.

That is, as shown in FIG. 1, on the surface of the metal belt (1),
Solidification begins immediately after the rear fixed weir (5). Due to the presence of this rear fixed weir (5), the solidification starting point on the surface of the metal belt (1) becomes uniform, and the formation of hot water wrinkles and double skin due to non-uniform solidification starting point, Non-uniformity in the thickness of the coagulated layer, etc. is prevented.

If the injection flow (7) is located at or near the rear fixed weir (5), the solidification start point will be disturbed, and because the solidified shell is thin, the solidified shell that has been solidified will be remelted. ,
Excellent surface quality. This makes it difficult to extract thin plates (slabs) of uniform thickness.

Further, after the solidified layer (slab) has been extracted from the molten metal pool (8), or when the injection flow (7) is positioned at the end of the molten metal pool (8) on the slab extraction side, The heat and falling energy of the injection stream (7) will eventually damage the solidified layer that has developed up to that point, impairing the surface quality of the thin plate (slab) and making the thickness non-uniform.

According to research by the present inventors, the injection flow (7) is at least 100 mm from the slab extraction side surface of the rear fixed weir (5).
For the reasons stated above, it is necessary to position the metal belt within 90% of the length of the metal belt moving direction of the water reservoir (8).

Now,? Thin plate (slab) extracted from i% pool (8)
9) is further rolled or shaped by a pair of rolling rolls (10) and wound up by a winding device (11).

It is a thin plate (strip) coil (12).

Effects of the Invention This invention can produce thin metal sheets with excellent surface quality and uniform thickness with high productivity without worrying about breakouts or ruptures, so it is possible to manufacture thin metal sheets with excellent surface quality and with high productivity. This greatly simplifies the process, resulting in significant energy savings and cost savings.

[Brief explanation of drawings]

FIG. 1 is an elevational view illustrating the thin plate casting apparatus of the present invention. 111φφ metal belt, 2・kai・pulley, 311 fist・
Cooling device, 4. Fist/(movable) side base, 5. φ/ (fixed type) rear ring, 6... Injection device, 7... Injection flow, 8
. . . Hot water reservoir, 9 . . . Solidified thin plate, 10 . . . Roll, 11 . . . Winding device, 12 . . IIg, plate coil.

Claims (1)

[Claims] an endless metal belt inclined so that the casting direction is upward and a cooling device attached to the back side; a rear fixed weir for forming a pool of molten metal on the metal belt; 1. A thin plate casting apparatus comprising a movable side weir, the injection position of molten metal being located a predetermined distance from a fixed rear weir.