JPH07100609A - Device for rapidly cooling hot slab - Google Patents

Abstract

PURPOSE:To produce high quality slabs at a speed corresponding to speed of a continuous casting machine by rapidly and efficiently cooling the slabs using a device which is provided with a holding, vertical moving and carrying means (slab traverser), a cooling tank, a temporary storage for cooled slabs and a movable crane. CONSTITUTION:The hot slab A is carried in a cooling device 10 by a carrying table 20 and thrown in the cooling tank 14 at a specific position using the traverser. After the cooled slab is taken out and carried in the temporary storage place 16, the cooled slab A is carried out from the device by the overhead crane. The slab traverser 12 consists of a holding part 22 by which the slab A is held, a vertical moving part 24 by which the stab is vertically moved (shown by the arrow b) and a carrying part 26 by which the slab A is carried in the direction about orthogonally crossing with the direction on which the slab A is carried by the carrying table 20 (shown by the arrow C). The slab traverser 12 is mounted on a rail for moving 30 which is supported on a frame 28 and the carrying part 26 is made self-traveling on the rail.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rapid cooling device for a high temperature slab capable of rapidly cooling a high temperature slab manufactured by a continuous casting facility or the like with good efficiency.

[0002]

2. Description of the Related Art Stainless steel and alloy steel are required to have stricter quality than ordinary steel grades. Therefore, when manufacturing these steel types, after cooling the red hot continuous cast piece (hereinafter referred to as continuous cast piece) produced by the continuous casting equipment to the ambient temperature, it is necessary to perform surface inspection and flaw maintenance. It is common.

However, in some types of such stainless steel and alloy steel, the alloy elements and carbon contained in the steel are chemically bonded to each other during the cooling process of the slab to form a carbide, and this carbide is generated. It may be concentrated in the crystal grain boundaries. Concentration of some elements or compounds in a portion having a crystal structure means that a microscopic difference in concentration of components occurs in steel. Such a concentration difference adversely affects the gloss of the rolled steel sheet and various physical properties of the surface treatment.

In order to prevent this, among the steel grades among these grades that do not have the risk of undercooling cracks, in order to prevent the formation of carbides in the steel, the high temperature slab is immersed in a cooling bath such as a water bath. The rapid cooling suppresses the precipitation of carbides.

[0005]

As for the effect of such rapid cooling, the effect of suppressing the formation of carbides is greater when the material is cooled rapidly from a higher temperature state. Therefore, for rapid cooling of the slab, after continuous casting, the slab immediately after cutting with a torch cutter is lifted from the transport table by an overhead crane, etc., and the slab is put in a water tank placed under this crane until the slab reaches a prescribed temperature. When cooled, it is generally lifted from the water tank by the overhead crane.

However, this cooling work for lifting the slab by the overhead crane takes a long time to move up and down and move the slab, and it is difficult to perform the cooling work in synchronization with the production of the slab by the continuous casting machine. If the speed is high, the cooling operation will be significantly delayed with respect to the production of the slab. Therefore, most of the slab cooling work uses a method in which a slab is once placed in a temporary storage area and then a plurality of slabs are collectively put into a water tank by an overhead crane.

However, this method also has a problem that the formation of carbides partially progresses during the temporary occurrence, and since a plurality of slabs are put in a water tank at the same time in a stacked state, There is also a problem that a large temperature difference occurs between the superposed portion of the slab and the other surface portion, and the warp of the slab becomes large.

An object of the present invention is to solve the above-mentioned problems of the prior art. Even in the continuous casting at a high speed, the slab production speed by the continuous casting machine is not significantly delayed, and the good efficiency can be obtained. The purpose of the present invention is to provide a rapid cooling device for high-temperature slabs, which can reliably perform rapid cooling of high-temperature slabs with no partial precipitation of carbides or warpage of slabs. .

[0009]

In order to achieve the above object, the present invention provides a slab elevating and moving means for holding and elevating a conveyed high temperature slab, and moving the slab elevating and moving means. A cooling tank, which is arranged at the lower part of the range, stores a plurality of high-temperature slabs in parallel in the moving direction of the slab elevating and moving means and rapidly cools, and a cooling by the cooling tank, which is arranged at the lower part of the moving range of the slab elevating and moving means. A rapid cooling device for a high temperature slab, comprising: a temporary storage place for temporarily placing the finished slab; and a crane for moving the slab placed on the temporary storage place.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A rapid cooling apparatus for a high temperature slab according to the present invention will be described below in detail with reference to the preferred embodiments shown in the accompanying drawings. FIG. 1 shows a schematic view of an example of a rapid cooling apparatus for a high temperature slab according to the present invention. In addition, in FIG. 1, (a) shows a schematic plan view and (b) shows a schematic front view, respectively.

The rapid cooling device 10 for a high temperature slab shown in FIG. 1 (hereinafter referred to as the cooling device 10) is basically a slave lifter traverser 12 which is a means for moving the slab A up and down.
(Hereinafter referred to as a traverser 12), a water cooling tank 14 as a cooling tank, a temporary storage space 16 for temporarily storing cooled slab A, and an overhead crane 1 for moving a plurality of slabs A collectively.
8 is included.

In the cooling device 10 of the illustrated example, the slab A continuously cast and cut into a predetermined length by a torch cutter is indicated by an arrow shown in FIG. a direction (Fig. 1
In (b), it is conveyed in the front direction perpendicular to the paper surface. Here, when the slab A is to be rapidly cooled (or temporarily placed), the slab A must first be connected to the traverser 1
It is conveyed to a predetermined position of the water cooling tank 14 by the No. 2. In addition,
If rapid cooling or temporary placement is not necessary, it may be directly transferred to the next step by the transfer table 20.

The traverser 12 holds and transports the high temperature slab A transported by the transport table 20 and inputs it into the water cooling tank 14, and also retains the slab A which has been cooled by the water cooling tank 14 and temporarily stores it. Transport to 16. Such a traverser 12 has a holding portion 2 for holding the slab A.
2, an elevating part 24 for elevating the slab A by elevating the holding part 22 (in the direction of arrow b), and the transport table 2
The moving unit 26 is configured to move the slab A by moving the slab A in a direction substantially perpendicular to the direction in which the slab A is transferred (direction of arrow c in the figure). The moving direction of the traverser 12 is not limited to the direction substantially orthogonal to the conveying direction of the slab A in the illustrated example, and a suitable moving direction may be set according to the layout and scale of the continuous casting equipment.

The holding unit 22 holds the high temperature slab A transported by the transport table 20 and the slab A that has been cooled by the water cooling tank 14, and can move up and down and move. The method of holding the slab A by the holding portion 22 is not particularly limited, and it can be held or held by various jigs / members,
Any known method for holding the slab A, such as a method using magnetic force or a combination thereof, can be used.

The holding part 22 is supported by the elevating part 24. In the traverser 12, the slab A is raised and lowered by raising and lowering the holding portion 22 by the raising and lowering portion 24.

As the elevating part 24, the slab A (holding part 2
Any known means capable of raising and lowering 2) can be used. Specifically, various types of wire winding electric motors, various cylinders such as oil and air, link mechanisms, rack and pinion, screw transmission, etc. can be used. Mechanical means etc. are illustrated. In particular, the wire winding electric motor is preferably used from the viewpoints that the ascending / descending speed of the slab A can be increased, the response of the control operation is good, the number of components is small, and the frequency of failure is small.

An upper end of the elevating part 24 is fixed to the moving part 26. The traverser 12 includes a mount 28,
28. The traverser 12 is mounted on a rail 30 for moving the traverser 12, and the moving portion 26 moves on the rail 30 by itself to move in the direction of arrow c in the figure, and is held. The slab A is moved in the direction of arrow c by being moved by the moving part 26 while the slab A is held by the part 22.

That is, in the cooling device 10 of the illustrated example, the traverser 12 holds the high temperature slab A transported by the transport table 20 by the holding part 22 and lifts it by the elevating part 24, and then moves the moving part 26 (traverser). 12) to move to a predetermined position on the water cooling tank 14,
Then, by descending by the elevating unit 24 and releasing the holding by the holding unit 22, the slab A is rapidly cooled by being put into a predetermined position of the water cooling tank 14 (submerged). On the other hand, the traverser 12 similarly holds the cooled slab A by the holding part 22, lifts it by the elevating part 24, conveys it onto the temporary storage space 16 by the moving part 26, and then elevates it.
4 and the holding portion 22 is opened, the temporary storage space 1
Place on 6.

As the moving part 26, various moving means can be used as long as the holding part 22 can move while holding the slab A. Self-propelled by wheels such as shown in the figure, screw type. Any known means can be used, such as one using transmission or winding transmission. In particular, the self-propelled type using wheels is preferably used in terms of moving speed, failure frequency, and the like.

If the water cooling of the slab A is unnecessary, the slab A is directly transferred to the temporary storage space 16 by the traverser 12.
May be transported and placed.

The water cooling tank 14 is for submerging the high temperature slab A into water and quenching it.
That is, in the illustrated example, the slabs A are arranged below the rails 30 and will be described in detail later, but the slabs A can be arranged in parallel in the direction substantially orthogonal to the conveying direction of the conveying table 20, that is, in the moving direction of the traverser 12 to cool them. it can. In the cooling device 10 of the present invention, the method of rapidly cooling the high temperature slab A is not limited to the water cooling in the illustrated example, and various refrigerants other than water may be used. Further, the supply amount of the refrigerant per unit time may be appropriately controlled.

The number of slabs A that can be put into the water cooling tank 14 is determined by the sizes of the water cooling tank 14 and the slabs A to be cooled, and is not particularly limited. Therefore, the maximum number of sheets to be put into the water cooling tank 14 in the rapid cooling operation of the slab A of the cooling device 10 of the present invention is the size and steel type of the slab A (cooling time corresponding thereto), continuous casting speed, slab length, before cooling. It may be appropriately determined according to the temperature of the slab A, the temperature of the slab A after cooling, the cooling capacity of the refrigerant used, and the like.

In the cooling device 10 of the illustrated example, the slab A, which has been cooled by the water cooling tank 14 as described above, is temporarily placed below the moving range of the traverser 12, that is, below the rail 30 in the illustrated example. It is placed on the storage 16. When the number of slabs A placed on the temporary storage 16 reaches a predetermined number, the overhead crane 18 movable in the directions of arrows b and c in the figure conveys the slabs to a predetermined storage and the next step.

The overhead crane 18 used in the cooling device 10 of the present invention is not particularly limited, and any known crane used for transporting or moving the slab A can be used in an ordinary steelmaking line or the like. .

The number of slabs A transported by the overhead crane 18 at one time is not particularly limited. Needless to say, the slabs A piled up in the temporary storage area 16 are grasped per work so as not to accumulate (congestion). The number of sheets, working speed (traveling speed, hoisting, hoisting speed), etc. may be determined.

An example of the quenching operation of the slab A by the cooling device 10 of the present invention will be described below with reference to FIGS. 2 and 3. 2 and 3, for simplification of the drawings, the traverser 12 shows only the holding portion 22, and details of the transport table and the overhead crane 18 are omitted.

First, when the water cooling tank 14 is empty, the traverser 12 holds, raises, moves, and moves the slab A as described above.
As shown in FIGS. 2A and 2B, the slab A is lowered and opened, and the slab A is sequentially moved from the position closest to the transport table 20 (that is, the position 1 in the drawing) to the water cooling tank 1.
Put in 4 and submerge in water to quench.

In this way, when the slab A is loaded up to the position 7 as shown in FIG.
As shown in (c), the traverser 12 takes out the first submerged slab A, that is, the slab A put in the No. 1 position from the water cooling tank 14 and places it in the temporary storage space 16.

The next slab A by the transport table 20
2D, the traverser 12 holds the slab A and puts it in the empty position 1 of the water cooling tank 14 to cool it with water, as shown in FIG. 2 (d). Figure 3
As shown in (e), the second loaded slab A, that is, the slab A placed at the second position, is transported to the temporary storage space 16. Next, as shown in FIG. 3 (f), the slab A that is next transported to the vacated position 2
Is charged and cooled. By repeating the above operation, the high temperature slab A continuously cast and transported by the transport table 20 is rapidly cooled and transported to the temporary storage space 16.

Here, the slab A placed on the temporary storage area 16
When the number of sheets reaches a predetermined number, a plurality of slabs A are conveyed to a predetermined place or the next step by the overhead crane 18 shown in FIG.

According to the cooling device 10 of the present invention as described above, the traverser 12 capable of moving up and down the slab A,
By using a water cooling tank 14 for arranging a plurality of slabs A in the moving direction of the traverser 12 to cool them, a temporary storage space 16 for mounting a plurality of cooled slabs A, and an overhead crane 18, a high temperature slab It is possible to rapidly cool slab A with high efficiency by following the production speed of slab A without waiting for A or stacking multiple sheets into a water-cooling tank. It is possible to stably produce high-quality slabs that have no

As an example, the cooling device 10 shown in FIG.
In, the size of the water cooling tank 14 is vertical (direction of arrow a) 1
3.5m, side (direction of arrow c) 19.9m, depth 1.2m
Then, the ascending / descending speed of the ascending / descending portion 24 (wire winding motor) of the traverser 12 is 20 m / min, and the ascending / descending stroke is 3.
When the moving speed of the moving unit 26 (using a self-propelled trolley) is 33 m and the moving speed is 150 m / min, a slab having a thickness of 200 mm, a length of 5.0 to 5.5 m, and a width of 1230 mm is shown in FIG. FIG. 4 shows the continuous casting speed and the slab cooling practicability at the continuous casting speed, that is, the followability of the cooling speed with respect to the continuous casting speed, when rapid cooling is performed as shown in FIG. 3 (solid line).

For comparison, a slab A of the same size is used.
4 is also shown in FIG. 4 (hatched area surrounded by a dotted line) for the following property of the cooling rate when the cooling is performed in the conventional rapid cooling method using the overhead crane. In addition, this cooling was performed by a method in which an overhead crane using electric wire hoisting was used and a water cooling tank was charged and extracted one by one. The lifting speed of the overhead crane is 8 to 20 m / min, and the moving speed is 80.
~ 150 m / min.

As shown in FIG. 4, in the conventional cooling method, the followability decreases as the continuous casting speed increases,
In particular, when the continuous casting speed is 0.5 m / min or more, the cooling followability is significantly reduced, and in order to rapidly cool all the slabs A, the continuous casting speed must be significantly reduced. On the other hand, according to the cooling device of the present invention, the followability of the cooling rate with respect to the increase of the continuous casting rate is high, and the slab A can be rapidly cooled with high efficiency. It is possible to stably and efficiently produce a high-quality slab without any partial precipitation or warpage of carbide.

Although the rapid cooling apparatus for a high temperature slab according to the present invention has been described in detail above, the present invention is not limited to the above-mentioned examples, and various modifications and improvements can be made without departing from the gist of the present invention. Of course it is okay.

[0036]

As described in detail above, according to the rapid cooling system for a high temperature slab of the present invention, the rapid cooling of the slab can be performed with high efficiency, which is suitable for continuous casting at high speed. Correspondingly, a high-quality slab with no partial precipitation or warpage of carbide can be stably and highly efficiently manufactured.

[Brief description of drawings]

FIG. 1 (a) is a schematic plan view of a rapid cooling apparatus for a high temperature slab according to the present invention, and FIG. 1 (b) is a schematic front view thereof.

2 (a), (b), (c) and (d) are views conceptually showing an example of the slab rapid cooling operation in the rapid cooling apparatus for the high temperature slab shown in FIG.

3 (e) and 3 (f) are views conceptually showing an example of the slab rapid cooling operation in the rapid cooling system for the high temperature slab shown in FIG.

FIG. 4 is a graph showing the relationship between the continuous casting speed and the slab cooling feasibility in the present invention and the conventional high-temperature slab rapid cooling device.

[Explanation of symbols]

 10 Rapid cooling device for high temperature slab (cooling device) 12 Slave lifter traverser (traverser) 14 Water cooling tank 16 Temporary storage space 18 Ceiling crane 20 Transfer table 22 Holding part 24 Lifting part 26 Moving part 28 Stand 30 Rail A slab

Claims (1)

[Claims] 1. A slab elevating and moving means capable of holding, elevating and moving a conveyed high temperature slab, and arranging the slab elevating and moving means below a moving range of the slab elevating and moving means.
A cooling tank for storing and quenching a plurality of high temperature slabs in parallel in the moving direction of the slab elevating and moving means, and arranged at the lower part of the moving range of the slab elevating and moving means,
A rapid cooling device for a high temperature slab, comprising: a temporary storage space for temporarily storing the slab that has been cooled by the cooling tank; and a crane for moving the slab mounted on the temporary storage space.