JP3091814B2 - Continuous caster with easy model change - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous caster whose shape can be easily changed, such as a curved type and a vertical bent type.

[0002]

2. Description of the Related Art Conventionally, continuous casters used in continuous casting of steel, aluminum, and copper are of the following types.
For example, "Iron and Steel," 67th (1981) No. 8, 104
As shown in FIG. 1 on page 4, the types are classified into several types shown in (a) to (f) according to the roll arrangement, roll profile, and the like.

As shown in FIG. 5, conceptually, each type of continuous casting machine known in the art conceptually converts molten steel 1 from a tundish 2 through a dipping nozzle 3 to a cooling structure 4.
Is poured into a mold 6 provided with a vibrating device 5, cooled and solidified by the mold, and the obtained cast piece 7 is supported by a plurality of support rolls 8 arranged below the mold, and a plurality of support rolls 8 connected below the support roll 8. It has a structure for supporting and unloading via a slab support structure composed of a plurality of guide roll segments 10 composed of guide rolls 9.

[0004] The slab is supported by the slab support structure, and the unloading shape {vertical portion, curved portion (curvature), presence / absence of a horizontal portion, starting point, end point, etc.} of the above-mentioned "iron and steel" , The model names such as vertical type and vertical bending type are given. The characteristics of each model are shown in Table 1 below.

[0005]

[Table 1]

As shown in Table 1, each of these types has advantages and disadvantages associated with the above slab supporting shape (in the case of a curved shape, the curvature largely depends on the occurrence of cracks). Although it is selected according to the type, there are also cases where many types are cast, and it is preferable that the model can be arbitrarily changed according to the type.

However, in order to change this model, a major remodeling that requires a monthly facility stoppage is required. Therefore, the remodeling has been carried out only when there is a significant change in quality requirements. It is. In many cases, a type is selected and constructed according to the type of casting, and casting is performed for a type that is not optimal in terms of productivity and quality deterioration to some extent.

[0008]

In a conventional continuous casting machine of a classification type, there is no almighty casting machine for casting high quality slabs for continuous casting of many types. If the types can be properly used, it is possible to improve the quality of the slab or the productivity. For example, the types 3 and 4 in Table 1 are properly used.

Conventionally, there has been an example in which the table is switched from 4 to 3 in Table 1. In this example, the roll segments of the molten steel pot, the tundish, and the horizontal support portion can be used after the switch, but the mold from the mold to the curved portion can be used. Up to the roll segment, it was necessary to replace the support frame, including its support frame, and a major remodeling was required with long-term equipment downtime. After the remodeling, it was fixed to the three types shown in Table 1.

According to the present invention, it is possible to easily change the type between the curved type and the vertical bending type while leaving most of the roll segments intact. Of course, equipment related to molten steel such as a molten steel pot and a tundish is also available. It can be used in both types, depending on the change of casting type, by changing the range of mold support rolls that were frequently replaced due to the change of slab size or the wear of equipment, or by slightly increasing the replacement range. Another object of the present invention is to provide a continuous casting machine capable of changing the type easily and in a short time.

[0011]

Means for Solving the Problems The first invention of the present invention is:
A bay following the vertical section formed by the support roll below the mold
After bending to a radius less than the basic casting radius at the bend, support
Roll arrangement to return to the basic casting radius in the roll equipment
In model changes will readily continuous casting machine, characterized in that the support roll is disposed with the second invention, in the first invention, on following the support roll and a support roll
Basic casting radius at the curved part formed by the roll segment
After bending to the following radius, the equipment of the upper roll segment
With a roll arrangement to bend back to the basic casting radius within
This is a continuous caster in which the type is easily changed, which is characterized by disposing a metal segment .

In the above description, the basic casting radius means a casting radius having the longest roll section defined by the radius of the curved portion casting radius.

[0013]

In the present invention, the type of a continuous casting machine such as a curved type and a vertical bending type can be easily and simply changed by replacing a mold, a support roll and a part of an upper guide roll segment connected below the support roll. Can be changed in a short time.

Therefore, it is not necessary to provide a plurality of continuous casters of a special type having high suitability when casting a plurality of varieties as in the prior art, and the type can be changed without significant remodeling. Cost and equipment downtime can be significantly reduced.

For example, a variety having high crack susceptibility can be cast in a curved multipoint type to obtain a slab free of surface cracks and cracks immediately below the surface layer. In addition, in the case of a type in which nonmetallic inclusions and air bubbles are harmful, it is possible to obtain a cast piece free of nonmetallic inclusions and air bubbles by casting with a vertical multipoint bending type. In this way, it is possible to easily and quickly change the type to a type suitable for casting of the type according to the type to be cast.

The change of the model in the present invention means an arbitrary change of the model or a change (modification) to a dedicated model. The continuous casting machine of the present invention is applied to the types (c) to (d) among the various types described in the above “Iron and Steel”.

[0017]

EXAMPLES (Example 1) An example of a continuous casting machine according to the present invention will be described below based on an example in which the invention is applied to a general steel continuous casting machine. The continuous casting machine used here is a curved multipoint correction type continuous casting machine having no vertical portion in the slab support structure, and as shown in FIG. 6 having a cooling structure 4 and a vibration device 5 attached thereto
Slab 7 which has been cooled and solidified by this mold.
A plurality of support rolls 8 arranged at the bottom of the mold,
It has a structure in which it is carried out while being curved and supported via a slab support structure constituted by a plurality of roll segments 10 composed of a plurality of guide rolls 9 connected below.

In the description of the continuous casting machine shown in FIG. 1, since the difference from the conventional continuous casting machine (FIG. 5) is not clear, the roll arrangement which is a main part of the continuous casting machine of the present invention is described in detail in FIG.
Embodiments of the present invention will be described with reference to FIGS. In this embodiment, it is possible to switch (change) two types of a curved multipoint straightening continuous casting machine for steel and a vertical multipoint bending multipoint straightening continuous casting machine. By using the basic part of the multi-point straightening type continuous casting machine as it is and replacing the mold, the support roll and a part of the upper roll segment following this, the vertical multi-point bending type continuous casting machine shown in FIG. It is possible to switch (change) between the two models.

In the curved multipoint correction type continuous casting machine shown in FIG. 2A, the casting radius of the slab support of the curved portion slab support structure formed by the plurality of support rolls 8 and the plurality of roll segments 10 is 12530 mm. The basic casting radius is R1. In the roll segment at the end of the curved portion, the casting radius (R2 to R5) is gradually increased and connected to the horizontal portion.

In the vertical multi-point bending / multi-point correction type continuous casting machine shown in FIG. 2B, a vertical portion is formed in the upper region of the mold 6 and the support roll 8, and 7500 is formed in the subsequent support roll region.
mm, the casting radius (R2 to R6) is designed to be gradually reduced, and after holding for an appropriate section at 7500 mm, the casting radius (R2 to R6) is gradually reduced within the range of the first roll segment 18 of the upper guide roll following the support roll. R7 to R9) are increased to connect to the basic casting radius R10 of 12530 mm.

That is, in this example, by changing the uppermost roll segment 18 (from the mold 6 to the nineteenth guide roll 15) from the mold 6, the type can be changed between the two types. Here, the reason why the casting radius is gradually changed is to suppress the deformation (bending and unbending) of the slab to be equal to or less than the allowable value of slab crack generation. In addition, since the allowable value of crack generation differs depending on the type of casting, the value of the casting radius that is gradually changed may take a different value when limiting the type of casting target.

By setting such a roll arrangement, in this example, the rolls after the twentieth guide roll 14 and the roll arrangement are the same as those of the curved multipoint correction type continuous casting machine shown in FIG. Both types of the vertical multi-point bending type continuous casting machine (b) are exactly the same, and do not need to be replaced.

Here, the replacement range of the support roll and the guide roll (roll segment) is defined by the angle θ between the casting radius line a and the horizontal line b at the center position of each roll to be replaced.
When expressed by {see FIG. 2 (b)}, the range is 24 degrees or less. This angle θ is preferably set to 30 degrees or less in order to obtain the effect of the level described later.

The height of both types of continuous casting machines is set to 3 mm, which is practically no problem. This can be exactly the same with some modifications. The difference between the horizontal distance between the mold and the final straightening point between the two types is about 370 mm, so that the tundish can be shared if the tundish equipment can be moved when the equipment is constructed.

In this way, by simply changing the mold 6 to the nineteenth guide roll 15, two types of the curved multi-point straightening type and the vertical multi-point bending type continuous casting machine having a 1.5 m vertical portion are provided. In the meantime, the model can be changed easily and in a short time (replacement is several hours, remodeling is several days). At this time, depending on the equipment configuration of the continuous casting machine, a part of the mold vibrating device may be replaced.

Next, a specific method of changing the model will be described with reference to FIG. The mold 6, the support roll 8 and the roll segment 18 to be replaced when the model is changed are prepared for each model, and the mold 6 and the support roll 8 are incorporated in the collective exchange frame 16 and stored in a predetermined place.

At the time of these replacements, the tundish 2 on the upper part of the mold 6 is evacuated in advance to a position where it does not interfere, the collective exchange frame is removed by an overhead crane, carried out to the storage place, and stored in the storage place. The exchange frame is carried in and mounted, and the mold 6 and the support roll 8 are replaced.

The roll segment 18 is replaced by using a special extraction crane 17 and an overhead crane. If a sufficient space is secured in the upper space at the time of construction, this roll segment 18 can be
It can be replaced with a general overhead crane. The batch exchange frame 16 is positioned on the reference surface 19, and the roll segment 18 is positioned on the reference surface 20.

In the continuous casting machine having a curved multipoint correction type shown in FIG. 2A and the continuous casting machine having a vertical multipoint bending multipoint correction type shown in FIG. 8 relative position, roll segment 18 with respect to reference plane 20
Although the relative positions of the inner rolls are different, the molds, support rolls, batch exchange frames, roll segments, etc. are adjusted to the correct positions using liners and shims when assembling each device. Thus, in the continuous casting machine of the present invention, the type of the continuous casting can be changed in several hours to several days.

[0030] Incidentally, Oite in this example, the replacement range of the slab supporting structure, and support roll, although a guide roll (roll segment), these roles, a common function of support of the slab In order to facilitate continuous casting (optimizing the casting radius) and facilitate replacement of the mold and its attached equipment, the support range by the support roll may be longer than in this embodiment. In this case, a guide roll (roll segment)
The model may be changed without replacing the model.

The present invention is not limited to the above-described embodiment, and the type to be changed, the replacement range, the replacement structure, the replacement means, etc. are not limited to the range within which the constitutions of claims 1 and 2 can be satisfied. It is appropriately changed in consideration of the target product type (metal type and size), casting conditions, equipment conditions, factory layout conditions, and the like.

Next, the change of the type of the conventional continuous casting machine will be described with reference to FIG. In this example, the model is changed from the curved multipoint correction continuous casting machine of FIG. 2A to the vertical multipoint bending multipoint correction continuous casting machine of FIG. 2B. In this example, after the vertical portion is formed, the casting radius is gradually reduced, the radius is set to 9600 mm as the basic casting radius R7, and the bent back portion for gradually increasing the casting radius after forming the basic casting radius portion to an appropriate length is concentrated. Had formed.

As described above, when the bent portion is continuously concentrated and the appropriate section is formed with the basic casting radius, and then the bent-back portion is continuously concentrated, the continuous casting machine is used. Before and after the model change, the basic casting radius had to be changed so that there was almost no difference in the height of the continuous casting machine and the horizontal distance from the mold to the final bending return point.

As in this example, the basic casting radius 12530
In the case of remodeling to change the mm to 9600 mm, it is necessary to largely change the installation base frame 21 of the roll segment, concrete foundation, piping on the foundation surface, piping around the base frame, roll driving device attached to the roll segment In addition, the equipment requires a period of one to two months due to changes and modifications of the roll interval adjusting device and the like.

[0035]

According to the present invention, several types can be easily and quickly switched by exchanging a part of the support roll and a part of the upper guide roll segment connected below the support roll. . For example, varieties having high crack susceptibility can be cast with a curved multipoint straightening type continuous casting machine to obtain cast pieces without surface cracks and cracks just below the surface layer. In addition, in the case of non-metallic inclusions and bubbles of a type that is harmful, casting is performed with a continuous casting machine of the type of vertical multi-point bending type multi-point correction type to obtain a slab free of non-metallic inclusions and bubbles. be able to. Depending on the type to be cast, it can be easily and arbitrarily changed to a type that is highly suitable for casting of that type in a short time, and it is easy to change (remodel) to a dedicated type. Therefore, it is not necessary to install multiple continuous casters of a special type with high suitability for casting multiple types of products as in the past, greatly reducing equipment costs and improving the productivity and slab quality of continuous casting. It is possible to improve.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an example of a curved multipoint correction type continuous casting machine according to an embodiment of the present invention.

FIG. 2 shows a curved multipoint correction type according to an embodiment of the present invention;
The rolls of the continuous casting machine for switching the vertical multi-point bending multi-point straightening die are schematic side views showing the arrangement. FIG. 1 (a) shows the case of the curved multi-point straightening type continuous casting machine shown in FIG. The figure shows the case of a vertical multipoint bending multipoint correction type continuous casting machine.

FIG. 3 is a schematic side view showing an example of a model exchange procedure between a curved multipoint straightening continuous casting machine and a vertical multipoint bending multipoint straightening continuous casting machine according to an embodiment of the present invention.

FIG. 4 is a schematic side view showing a remodeling procedure for changing a model between a curved multipoint straightening continuous casting machine and a vertical multipoint bending multipoint straightening continuous casting machine in a conventional example.

FIG. 5 is a schematic side view showing the structure of a conventional general continuous casting machine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Molten steel 2 Tundish 3 Immersion nozzle 4 Cooling structure 5 Vibration device 6 Mold 7 Cast piece 8 Support roll 9 Guide roll 10 Roll segment 11 Cutting machine 12 Molten steel pot 13 Support roll under mold 14 20th guide roll 15 19th guide Roll 16 Batch change frame 17 Roll unloading crane 18 Top roll segment 19 Batch change frame setting reference surface 20 Roll segment setting reference surface 21 Roll segment setting base frame (curved portion) 22 Roll segment setting base frame (horizontal portion)

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Hiroyuki Fujii 2-6-3 Otemachi, Chiyoda-ku, Tokyo New Nippon Steel Corporation (56) References JP-A-60-250863 (JP, A) JP-A-52-75617 (JP, A) JP-A-58-29548 (JP, A) JP-A-2-263552 (JP, A) JP-A-51-81736 (JP, A) JP-A-6-246397 (JP, A) JP-A-5-277675 (JP, A) JP-A-3-106540 (JP, A) JP-A 62-113845 (JP, U) (58) Fields investigated (Int. Cl. ⁷⁾ B22D 11/128 B22D 11/128 330 B22D 11/04 317 B22D 11/041

Claims (2)

(57) [Claims] 1. Formed by a support roll below a mold
Bend to radius less than the basic casting radius at the curved part following the vertical part
Then bend to the basic casting radius in the support roll facility
An easily changeable type continuous casting machine, comprising a support roll having a return roll arrangement . 2. An upper roll segment following a support roll.
To a radius less than the basic casting radius
After bending, the basic casting half
Roll segment with a roll arrangement that returns to the diameter
2. The continuous casting machine according to claim 1, wherein said continuous casting machine is arranged .