JPS58218349A - Stationary side plate of continuous casting device of thin steel plate - Google Patents

Abstract

PURPOSE:To prevent the abrasion of circulating bodies and to improve the life thereof by mounting sliding plates to both side edges of stationary side plates of an inverted triangular shape for regulating the short side of an ingot in the parts thereof contacting with the circulating bodies. CONSTITUTION:A stationary side plate 3 is formed into an approximate triangular shape of an upward divergent and downward convergent shape, and the inside surface to contact with molten steel is constituted of a refractory material having excellent heat resistance. Sliding plates 13, 13 having excellent resistance to thermal sliding are fixed by means of bolts or brazing materials to both side edge parts of the plate 3 contacting with circulating bodies 1, 2. The abrasion and scratches on the inside surfaces of the bodies 1, 2 and the consequent leakage of molten steel are thus prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixed side plate of a continuous manufacturing apparatus for thin steel sheets, and particularly! This is a proposal for a fixed side plate equipped with a sliding plate used for manufacturing thin steel plates directly from molten steel without going through the process of ingot or rough rolling.

Conventionally, in order to manufacture thin steel sheets, a steel ingot was first created through an ingot treatment, then it was bloomed into a slab with a thickness of 100 to 800 mm, and then further rolled into a slab with a thickness of 80 mm. The steel plate was made into a thin steel plate with a thickness of about 100 mL, and then hot-striped into a thin steel strip with a thickness of 1Qs+x or less.

On the other hand, there is a conventional technique as shown in FIG. 1 in which a thin slab is directly cast by a continuous casting method and then rolled into a thin steel plate. In this technique, molten metal (molten metal) is injected into a water-cooled mold 102 through an injection nozzle 101, a solidified shell 108 is entirely generated along the casting wall, and then the solidified shell 108 is moved by guide rolls 104, etc. In this method, thick slabs are continuously drawn out through a steel plate, and then rough rolled to make thin steel plates.However, this method has the following problems. Since the thickness of the injection nozzle 101 is determined by the diameter of the injection nozzle 101, the smaller the nozzle diameter is, the better.

However, in order to prevent the molten metal from solidifying inside the nozzle during injection, it is necessary to set the nozzle diameter to 1001 + 1 m or more, and generally a nozzle diameter of 150 to 170 m is used. are doing. Therefore, the thickness of the slab that can be cast is at least 130 pieces, and usually 2oo4z.
It will be as thick as ao. In this sense, the mold used in the conventional continuous casting method described above has a substantially rectangular parallelepiped shape as shown in FIG. 1, and has a structure that makes it difficult to draw out a thin slab.

On the other hand, as a further improvement to the conventional continuous casting apparatus, a pair of circulating metal belts (circulating bodies) are arranged opposite each other in the shape of a concave area with an upper width lower than the upper part. A casting space is formed in which the casting is performed directly from the bottom.
Contact: There is a technology that allows the inner steel plate to be pulled out,
Even in the case of this device, there were the following drawbacks.

□ That is, even if it is possible to obtain a casting space with a downwardly concave shape in which the lower end on the drawing side is smaller than the diameter of the injection nozzle, the extent of this is small. For example, a large amount (more than aoot/Hr)
In order to supply hot water using the injection nozzle 1, at least the inner diameter cross section p1 product (100/2)2×π(-) or more (inner diameter 1
Therefore, a nozzle with an outer diameter of 130 mm or more is required. Using such a large capacity nozzle, 800t/
In order to continuously cast thin steel plates with a thickness of 100 mm or less while supplying hot water of f(r or more), the shape of the stationary side plate constituting the short side of the casting space must be tapered to a degree greater than natural solidification shrinkage. In this regard, conventional thin steel sheet continuous casting equipment has a structure in which all four sides forming the casting space are water-cooled, and especially on the side of the fixed steel plate that corresponds to the short side. In order to form a solidified shell at the same speed as the surface, it is impossible to narrow down the concave shape of the short side surface more than the natural shrinkage due to solidification.In short, this fixed side plate used in such a device In this case, the ratio of the width difference between the top and bottom of the row to the height of the casting space (the height of the casting space and the length of the fixed side plate) to form a downward converging shape is at most 1.5% natural shrinkage. It was difficult to directly manufacture extremely thin steel plates.

This invention was developed with the aim of overcoming the drawbacks of the conventional fixing and side plates for thin steel plate casting equipment mentioned above. In addition to proposing a fixed side plate for surface regulation, we also propose a structure for a fixed side plate with an improved sliding surface with the circulating body. 4.1 Details of the configuration will be explained below with reference to the drawings.

Fig. 2 of the drawings shows a preferred embodiment of the continuous casting apparatus of the present invention, and 1 and 2 in the drawing show an endless casting system while maintaining a gap (reservoir) for holding the cast metal over a certain distance. It is a circulating body (long side, against the wall) that is placed in a pair of opposing positions that move (circulate) in a cylindrical manner. In addition, 8 in the figure is a fixed side plate using a cast slab (steel plate) short side wall gauge located at the side edge between the opposing two picture rings 1 and 2, and has a wide upper part and a concave lower part shape. It is approximately triangular. A casting space is formed by these fixed side plates 8 and the pair of circulation bodies 1.2. The casting space, that is, the molten metal holding area 4a located in the upper part that corresponds to the molten steel pool, has a cross-sectional shape on the side that corresponds to the plate thickness surface. However, the fixed side portion 8 forms a substantially triangular shape with a downward convergence, and a pair of thickness adjustment openings 5, 51 are arranged at the 9th part of the narrowest minimum cross-sectional area. The thickness adjustment roll 5
, 51 is approximately equal to the product board thickness.

The part continuing below the molten metal holding area 4a is a solidified shell growth area 4b, where the solidified shell 6 that has grown and formed along the inner surface of the circulating body 1.2 is rapidly cooled and becomes a thin steel plate 7. As the circulating bodies 1 and 2 move, they are extracted sequentially from the bottom.

Water-cooled cooling plates 8 and 9 are provided on the back surfaces of the circulation bodies 1 and 2 corresponding to the molten metal holding area 4a and the solidified shell growth area 4b, respectively.
is installed to cool the circulation bodies 1 and 2. 10 shown
is the injection nozzle.

In the case of the apparatus described above, the fixed side plate 3 corresponding to the molten metal holding area 4a has an inverted triangular casting space, which eliminates the conventional drawbacks of using a slit-type nozzle.

However, in such a continuous casting device, in order to smoothly continuously cast the solidified shell 6 without breaking or bulging, it is necessary to remove the solidified shell from the surface of the fixed side plate 3. It is desirable that the growth starts at a position immediately before or immediately after the minimum gap for installing the thickness adjustment layer 17515'. For example, if the solidification start point occurs far before the minimum gap, the solidified shell is likely to break and the load on the thickness adjustment rolls 5, 5I increases, making stable continuous casting difficult. become.

On the other hand, if the solidification of the surface in contact with the fixed side plate 8 occurs far below the thickness regulating rolls 5, 5', this is because the fixed side plate 8 is of a fixed type without any oscillation. Seizure between the solidified shell 6 and the surface of the fixed side plate 8 is likely to occur, resulting in breakage of the solidified shell 6 and steel leakage.

Therefore, when we examined the structure of the molten metal holding area 4a of the fixed side plate 3 of the apparatus according to the present invention, we found that the formation of the solidified shell 6 on the side in contact with the short side surface of the steel plate, at least on the long side of the molten metal holding area 4a. It was found that it is effective to make the fixed side plate 3 made of a refractory material suitable for slow cooling in order to meet this requirement. did.

Based on the above-mentioned knowledge, the structure of the fixed side plate of the present invention, as shown in FIG. It is composed of a refractory 11, and on the other hand, the part that continues directly below the refractory 11, that is, the part below the molten metal holding area 4a that is in contact with the injected molten metal and corresponds to the casting space, is spaced at intervals equal to the width of the slab thickness. Quenching plate 1 with
2 are installed in series, and when the solidified shell 6 reaches a position where a slab of a predetermined width can be obtained, the solidified shell 6 is rapidly cooled to become a strong slab, thereby making it compatible with high-speed production and thinning. .

Then, sliding plates 13 and 13' made of copper or ceramics having excellent heat-resistant sliding properties are fixed to both ends of the refractory fixed side plate 3 in contact with the circulating bodies 1 and 2 via bolts or brazing material. do. The reason why the sliding plates 13 and 13' made of copper or the like are installed on the sliding surfaces of the circulating bodies 1 and 2 is that wear and scratches are likely to occur on the inner surfaces of the circulating bodies 1 and 2 due to sliding. This is because this tends to lead to accidents such as molten steel leakage and shortens the service life.

In short, the purpose of attachment is to reduce the frictional resistance between the two.

Note that the sliding plates 13 and 1 have a remarkable cooling effect on the fixed side plates 8.
Even if 3' is used, the intended effect will not be affected at all since most of the area including the center is occupied by the refractory material 11.

As an example continuous casting device, the circulating body has a width of 1 ooms and a thickness of 2
The injection nozzle has an outer diameter of 1.
4.0 l+ll+L, inner diameter 701+lJ+, made of alumina graphite is used, while the fixed side plates are made of fused silica refractories with copper sliding plates of water-cooled jacket structure and thickness of 7-thick installed on both sides of the refractories. It was carried out using a

The width of the upper part that forms the casting space (thickness including the sliding plate) is 2001 ns, and the width of the lower thickness adjustment roll part is 8012 m.
.

When a steel plate with a width of 800mm was drawn continuously at a speed of 1/ml, it was possible to produce a steel plate with a clean surface. In addition, the chemical composition of the steel material is Olo,
04%, In10. , llO% , Plo, 023
%.

A material containing 10.016% S and 042% Al2O was used.

In addition, the circulatory body is completely free from scratches and has a significantly longer lifespan. For example, the conventional lifespan was replaced after a throughput of 5000 tons, but with the present invention! In the above embodiment using the foot side walls, the service life could be extended to 15,600 tons of molten steel.

As explained above, when the fixed side plate of the present invention is used, it is possible to delay the solidification of the short sides, so high-speed production of thin steel plates is possible, and it is also effective in preventing breakage of the solidified shell and bulging, etc. . Moreover, by using such a fixed side plate with a sliding plate, there is also the effect of significantly improving the service life of the circulating body itself and the circulating body.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of a conventional continuous casting apparatus. FIG. 2 is a partial sectional view of a continuous thin steel plate casting apparatus according to the present invention. FIG. 8 is a perspective view of a stationary side plate according to the present invention. 1.2... Circulating body 3... Fixed side plate 4a...
- Molten metal holding area 4b... Solidified shell growth area 5, 51... Thickness adjustment roll 6... Solidified shell 6'... Molten steel 7...
- Solidified metal plate 8, 9... Cooling plate 10... Injection nozzle 11... Refractory 12... Quenching plate
13, 13'... Sliding plate patent applicant Kawasaki Steel Corporation Figure n Figure 3

Claims (1)

[Scope of Claims] 1. A circulating body arranged opposite to each other, which circulates while maintaining a gap for holding cast molten steel over a certain distance, and a pair located on both side edges between the circulating bodies. In the fixed side plate of a thin steel sheet continuous casting apparatus that constitutes a casting space with a fixed side plate, the fixed side plate is connected to a substantially triangular molten metal holding part with a concave shape at the top and a lower part, and a solidified slab thickness following the fixed side plate. The molten metal holding part is composed of a solidified shell growth region having approximately the same width, and both edges of the molten metal holding part in contact with the circulating body are made of a gradually resistant material, and sliding plates are attached to both edges. A fixed side plate of a continuous thin steel plate casting apparatus characterized by: