KR101460284B1 - Device and method for levelling strip - Google Patents

Abstract

A plurality of rolling steel plates having a thickness equal to or less than the thickness of the steel material are arranged at intervals along the progress line of the rolled steel plate so as to perform plastic bending at an appropriate bending curvature according to the thickness of the steel plate, Wherein the calibration roll comprises a first roll and a second roll having different diameters, wherein the first roll and the second roll are arranged one above the other to form a set, The present invention provides a rolled steel plate calibrating device having a structure in which a plurality of rollers are arranged alternately up and down.

Description

Technical Field [0001] The present invention relates to a rolled steel plate correcting apparatus and a calibrating method,

The present invention relates to a steel plate correcting apparatus. More particularly, the present invention relates to a rolling steel plate calibrating apparatus and a calibrating method that can perform plastic bending with an appropriate radius of curvature according to the thickness of the rolled steel plate.

Generally, in the thick plate process, all products with different steel types, thicknesses and widths are produced in one line. Depending on the thickness of the rolled steel plate, the thickness of the material (thickness: ~ 15mm) (Thickness: 40mm or more).

Rolled steel sheets are produced by heating, rolling, cooling, and calibrating. After reheating the hot slab or material, it is rolled to the desired size and cooled to obtain the desired material. Through this process, residual stress due to plastic deformation and quenching occurs in the steel sheet, and the plate shape becomes uneven, so that the shape of the plate is flattened in the calibration process and the internal residual stress is reduced.

The shape defect and the residual stress which can not be removed in the inline calibration process are calibrated offline once again, and the final product is completed. The off-line calibration facility is larger than the on-line calibration facility because the high temperature (200 ~ 700?) Steel plate is applied online and the low temperature (less than 200?) Steel plate is calibrated offline.

The roller calibrator of the conventional thick plate process is arranged so that a plurality of rolls are arranged in an up and down zig-zag manner irrespective of hot or cold and the vertical gap between the upper and lower rolls is set smaller than the thickness of the steel sheet, have.

At this time, the bending amount (upper roll reduction amount) is set to be large in order to make a uniform residual stress at the entrance side of the calibrator, and the bending amount is made zero by making the vertical roll interval equal to the thickness of the steel sheet .

In recent years, steel plates for energy-transporting steel pipes have been strategically developed. Due to the trend of hardening of steel pipes, it is required to increase the strength of steel plates for steel pipes. This steel sheet steel plate is required to be cooled down under reduced pressure due to the characteristics of the production process. In most cases, the width of the steel plate is about 4 m wide and the cooling in the lateral direction is uneven in the cooling process. A defective level that can not be achieved occurs. In addition, shipbuilding heavy materials are being replaced by TMCP steels in general steel, and plate deformation is also increasing due to uneven cooling due to harsh cooling conditions. Therefore, there is a growing demand for effective correction of the steel sheet, which has a higher strength and a worsened shape, than the conventional steel sheet or steel plate.

Conventional calibrators are capable of calibrating design thicknesses of all thicknesses from a base material to a backing material. However, in practice, the calibration effect is good only in a heavy material region and the calibration effect is not large in a material of a material or a material of a rear material.

This is because the curvature of the material is a function of the diameter of the roll, the roll pitch, and the amount of indentation when the material is subjected to a bending deformation by the calibrator roll. In the conventional calibrator, the roll diameter and pitch are fixed, This is because the diameter and pitch of the rolls optimized for thickness are used. Therefore, there is a problem that the shape of the steel sheet does not become flat even if the steel sheet is calibrated under pressure.

In order to solve this problem, several calibrators with different roll diameters are installed in actual production sites, and a method of separating the heavy material into a calibrator with a small roll diameter and a calibrator with a large roll diameter are used according to the material thickness .

In addition, although a calibrator using rolls of large / medium / small diameter has been proposed, since the number of rolls of each caliber is smaller than that of a general calibrator, the calibration effect is insufficient, and if the number of rolls is increased, The applicability is poor. Similarly, a calibrator having a small roll calibrator and a large roll calibrator arranged in the longitudinal direction has been proposed. However, there is a disadvantage in that the length of the apparatus is increased to twice or more, and it is difficult to apply it to a plate. In addition, a method of calibrating a piece of work material by elevating and lowering a part of the work roll, and correcting the work piece by lifting the work roll one by one to increase the pitch. However, the above-mentioned conventional structure compensates for the disadvantages of the conventional structure in terms of space, but it is inadequate in terms of roll management because the structure is complicated and the upper work roll is used as a backup roll when the roll is lifted.

There is provided a rolling steel plate calibrating device and a calibrating method for performing a plastic bending process on a rolled steel plate having a thickness equal to or less than a thickness of a steel material at a bending curvature appropriate to the thickness of the steel plate, thereby improving the calibration efficiency.

Also provided is a rolling steel plate calibrating device and a calibrating method which are capable of uniformly calibrating in the width direction of the steel plate by minimizing roll shape change.

The calibrating apparatus includes a plurality of calibrating rollers arranged at intervals alternately up and down along the progress line of the rolled steel sheet, the calibrating rolls including a first roll and a second roll having different diameters from each other, Two rolls and one second roll may be arranged vertically so as to form a set and a plurality of sets may be arranged alternately up and down opposite to each other along the progress line.

And a calibrating step of flattening the rolled steel sheet subjected to the rolling process by passing through a calibrating device along a progress line, wherein the calibrating step includes a first roll and a second roll having different diameters from each other, Two rolls are vertically arranged to constitute a set and a plurality of sets are alternately arranged vertically opposite each other at intervals along the progress line so that the rolled steel sheet is fed to the first roll and the second roll of each set in turn And is subjected to a plastic bending process.

The first roll may have a relatively larger diameter than the second roll.

The first roll may have a relatively smaller diameter than the second roll.

The diameter difference between the first roll and the second roll may be a structure in which the diameter of a small roll is 1/2 of that of a roll having a large diameter.

And a back-up roll coupled to the calibrating roll to support the calibrating roll, wherein the diameter of the back-up roll supporting the calibrating roll may be greater than or equal to a D2 value satisfying I >

Here, ^{I = ((πd1 4/64} ) + (πd1 2/4) d3 2)) + ((πd2 4/64) + (πd2 2/4) (d2 2/4)), I '= ( and ^{(πD1 4/64) + (} πD1 2/4) D3 2)) + ((πD2 4/64) + (πD2 2/4) (D2 2/4)),

d1, d2, and d3 are the calibration roll diameter, backup roll diameter, and distance from the reference axis to the calibration roll center, respectively, in a conventional calibration device.

D1, D2, and D3 are the calibration roll diameter, backup roll diameter, and distance from the reference axis to the calibrating roll center, respectively, in the calibrator.

The rolled steel sheet may be a heavy material or a natural material.

According to the present embodiment as described above, an excellent correction effect can be obtained from the heavy material to the thin material.

In addition, since the shape of the article can be corrected only by the hot-calibrating process, the cold-calibrating process can be omitted and the productivity can be increased.

1 is a schematic view showing a progress line for calibrating a rolled steel plate according to the present embodiment.
Fig. 2 is a schematic view showing a calibration roll structure of a rolling steel plate calibrating device according to the present embodiment.
3 is a schematic view showing a calibration roll structure of a rolling sheet straightening apparatus according to yet another embodiment.
4 and 5 are schematic views showing the backup roll structure of the calibrating device of the conventional structure and the calibrating device of the present embodiment.
Figs. 6 and 7 are graphs showing the amount of deflection of the rolled steel sheet of the calibrating device according to the present embodiment in comparison with the conventional one.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Wherever possible, the same or similar parts are denoted using the same reference numerals in the drawings.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified, and that other specific features, regions, integers, steps, operations, elements, components, and / And the like.

All terms including technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

1 is a schematic view showing a progress line for calibrating a rolled steel plate according to the present embodiment.

As shown in Fig. 1, the rolled steel sheet has a heating section 100 for heating the slab, a rolled section 200 for rolling the slab, a rolling section for rolling the rolled section, And is commercialized through the calibration apparatus 10.

The orthodontic appliance 10 includes a plurality of calibrating rolls 20 arranged in a zigzag arrangement arranged at upper and lower alternating intervals along the progress line of the rolled steel sheet. The calibrating rolls 20 are set so that the distance between the rolls arranged vertically is set to be smaller than the thickness of the rolled steel sheet so that the rolling bending in the vertical direction is sequentially performed on the rolled steel sheet moved therebetween.

The orthodontic appliance 10 of the present embodiment has a structure in which a rolled steel sheet is calibrated with a bending curvature appropriate to the thickness of a heavy material having a thickness of 40 mm or less and a material having a thickness of 15 mm or less.

To this end, as shown in FIG. 2, the calibrating rolls 20 of the present embodiment include a first roll 22 and a second roll 24 of different diameters. Two of the first rolls 22 and one of the second rolls 24 are vertically arranged to form a set and a plurality of sets are arranged alternately up and down facing each other along the progress line. The groups may be arranged in three or as many as necessary.

In this embodiment, the first roll 22 has a larger diameter than the second roll 24. Thus, two rolls having a large diameter and one roll having a relatively small diameter form a pair. In each tank, a second roll (24) having a small diameter is disposed between the first rolls (22) having a large diameter, with the progress line interposed therebetween.

The structure in which the groups are arranged alternately up and down alternately along the progress line means that when two first rolls 22 are disposed at the lower portion and a second roll 24 is disposed at the upper portion as shown in FIG. The first roll 22 of the bath is disposed on the upper side and the second roll 24 is disposed on the lower side and the first roll 22 of the next bath is arranged again on the lower side and the second roll 24 is placed on the upper side .

The second roll 24 having a relatively small diameter can be made to have a half size as compared with the first roll 22 having a large diameter. If the diameter of the second roll 24 is larger than or less than half of the diameter of the first roll 24, it will not be possible to properly calibrate the article.

By arranging the two kinds of calibrating rolls 20 having different diameters in this way to calibrate the rolled steel plate, the bending curvature can be added in two forms according to the thickness of the rolled steel plate.

3 shows another embodiment of the arrangement of the calibrating rolls 20 of the calibrating device 10. [

As shown in FIG. 3, the calibration roll 20 of the present embodiment has a structure in which the first roll 26 is smaller in diameter than the second roll 28. Thus, two rolls having a small diameter and one roll having a relatively large diameter form a set. In each tank, a second roll 28 having a large diameter is disposed between the first rolls 26 having a small diameter, with the progress line therebetween.

3, when two first rolls 26 are disposed at the bottom and a second roll 28 is disposed at the top, the first rolls 26 of the next set are arranged at the top, The two rolls 28 are disposed at the bottom, and the first rolls 26 of the next set are arranged at the bottom again and the second rolls 28 are arranged at the top.

The following description will be made by way of example of a calibration apparatus having a calibration roll structure shown in the embodiment of Fig. Of course, the embodiment of FIG. 3 can also achieve the same effect through a calibrating roll having two different diameters.

By arranging the two kinds of calibrating rolls 20 having different diameters in this way to calibrate the rolled steel plate, the bending curvature can be added in two forms according to the thickness of the rolled steel plate.

That is, the present apparatus forms a small bending curvature necessary for the heavy material by the first roll 22 having a large diameter for the heavy material at the time of bending the rolled steel sheet, and by the second roll 24 having a small diameter for the thin material It is possible to form a large curvature necessary for the material.

Therefore, the effect of shape correction can be enhanced not only in the weight material but also in the high strength material through one correcting device. In addition, conventionally, since the calibration effector is insufficient, it is possible to calibrate only the hot material using the hot and cold cold calibrators simultaneously.

5, the calibrating apparatus 10 further includes a back-up roll 30 coupled to the calibrating roll 20 to support the calibrating roll 20.

The back-up roll 30 of this embodiment has a structure in which the diameter of the back-up roll 30 supporting the second roll is formed to be larger than that of the prior art in order to reinforce the section rigidity of the second roll 24, which is a roll having a small diameter have.

The calibrating roll of the calibrator has a length and diameter ratio of about 15 to 20 and is long and thin. Therefore, when a wide-width high-strength rolled steel sheet having a length of about 4 m is rolled down, a bending deformation occurs at the center of the calibrating roll in a convex shape in the width direction, and the correction in the width direction becomes uneven due to such deformation. To prevent this, a back-up roll is installed on the backside of the calibrating roll to support the widthwise bending of the calibrating roll.

The backup roll 30 plays a role of maintaining a proper interval between the calibrating roll 20 and the frame 32 in order to secure the load of the calibrating roll 20 to the frame and ensure the sectional rigidity of the calibrating roll set do.

The backup roll 30 is formed to have a large diameter, so that the diameter of the second roll 24 is made smaller than that of the prior art so that the reduced sectional rigidity can be reinforced.

In this embodiment, the diameter of the back-up roll 30 supporting the calibrating roll 20 may be formed to have a diameter equal to or larger than the D2 value satisfying I ≥ I 'in the following equation (1).

Here, equation (1)

^{I = ((πd1 4/64} ) + (πd1 2/4) d3 2)) + ((πd2 4/64) + (πd2 2/4) (d2 2/4)),

I a ^{'= ((πD1 4/64} ) + (πD1 2/4) D3 2)) + ((πD2 4/64) + (πD2 2/4) (D2 2/4)).

In FIG. 4, d1, d2 and d3 denote the diameter of the calibration roll 300 shown in the conventional calibration apparatus, the diameter of the backup roll 310, and the distance from the frame 320, which is the reference axis, to the center of the calibration roll 300, respectively. D1 is the diameter of the calibration roll 300 of the conventional calibrator and d2 is the diameter of the backup roll 310 in the conventional calibrator and d3 is the diameter of the center of the calibrating roll 300 in the frame 320, .

5, the diameter D1 of the calibrating roll 20 in the calibrator 10 of the present embodiment, the diameter of the backup roll 30 and the diameter of the calibrating rolls D2 is the diameter of the backup roll 30 supporting the second roll 24 and D3 is the diameter of the frame 32 that is the reference axis, ) To the center of the second roll (24).

The diameter of the backup roll 30 with respect to the second roll 24 satisfying I ≥ I 'can be obtained through the above equation (1). The thus obtained value is the minimum diameter of the backup roll 30, and the backup roll is formed larger than the diameter.

Hereinafter, the operation of the present embodiment will be described with reference to FIGS. 6 and 7 in comparison with a comparative example.

FIG. 6 is a result of numerical analysis of a warp shape of a steel plate after calibration by applying a calibrating device of a conventional structure and a calibrating device of the present embodiment to a general steel material having a thickness of 15 mm, It is determined whether or not the shape is defective.

In FIG. 6, the comparative example 1 is a conventional calibrating device composed of only a large-diameter calibrating roll, and the comparative example 2 is a conventional calibrating device composed of only a small calibrating roll. to be.

In all of the examples and comparative examples, the total number of rolls was 4 in the upper part and 5 in the lower part. In the case of Comparative Example 1, the calibrating roll diameter was 280 mm, and the diameter of the calibrating roll of 2 was 140 mm and the pitch was 300 mm in all of the comparative examples.

In the calibrator of the embodiment, the diameter of the first roll of the calibrating roll was 280 mm, the diameter of the second roll was 140 mm, and the pitch was 300 mm.

The amount of indentation was set to be the same for both Example and Comparative Example, and was set at 6 mm-4 mm-2 mm-0 mmm from the inlet side.

In FIG. 6, the horizontal axis represents the distance in the longitudinal direction of the rolled steel sheet, and the vertical axis represents the height of the rolled steel sheet in the vertical direction. When a portion having a vertical bending amount of 3 mm or more was formed over the entire length of the rolled steel sheet, it was judged that the shape was defective.

As shown in Figs. 6 and 7, the amount of deflection of the steel sheet before calibration is 20 mm at the tip / rear end, respectively. In Comparative Example 1, in which only a large-diameter calibrating roll was used, the warpage exceeded 3 mm at both of the front and rear ends, indicating a failure. In the case of Comparative Example 2 composed of only a small diameter calibrating roll, the amount of deflection at the tip was good at 1.5 mm, but the amount of deflection at the rear end was 4 mm, indicating a defective.

In the case of the embodiment, the tip end portion was 1.8 mm and the rear end portion was 2 mm, and the amount of deflection was 3 mm or less over the entire steel plate length.

As described above, in the case of a calibrating device composed of a roll having a small diameter or only a roll having a large diameter, the calibrating device is more suitable for either a blank or a heavy material. In this embodiment, The excellent correction effect can be obtained.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Of course.

10: calibration device 20: calibration roll
22, 26: first roll 24, 28: second roll
30: Backup Roll

Claims (7)

A plurality of calibrating rolls arranged at intervals alternately up and down along the progress line of the rolled steel sheet, and a backup roll coupled to the calibrating roll and supporting the calibrating roll,
Wherein the calibration rolls comprise a first roll and a second roll having different diameters, wherein the first roll and the second roll are vertically arranged to form a set, and the plurality of sets are alternately arranged in the vertical direction Lt; / RTI >
Wherein the diameter of the back-up roll supporting the calibrating roll is formed to a diameter equal to or greater than a D2 value satisfying I > I 'in the following formula (1).
Equation (1)
^{I = ((πd1 4/64} ) + (πd1 2/4) d3 2)) + ((πd2 4/64) + (πd2 2/4) (d2 2/4)),
^{I '= ((πD1 4/} 64) + (πD1 2/4) D3 2)) + ((πD2 4/64) + (πD2 2/4) (D2 2/4))
D1 = calibration roll diameter in the above calibration device,
D2 = backup roll diameter in said calibrating device,
D3 = distance from the reference axis in the calibration device to the center of the calibration roll,
d1 = calibrated roll diameter in the calibrating apparatus shown in Fig. 4 with the same size of the upper and lower calibrating rolls,
d2 = back-up roll diameter in the calibrating device shown in Fig. 4 with the same size of the upper and lower calibrating rolls,
d3 = the distance from the reference axis to the center of the calibrating roll in the calibrating apparatus shown in Fig. 4 with the same size of the upper and lower calibrating rolls. The method according to claim 1,
Wherein the first roll has a relatively larger diameter than the second roll. The method according to claim 1,
Wherein the first roll has a relatively smaller diameter than the second roll. The method according to claim 1,
Wherein the diameter difference between the first roll and the second roll is a half of the diameter of a small roll with respect to the roll having a large diameter. delete 5. The method according to any one of claims 1 to 4,
Wherein the rolled steel sheet is a heavy material or a mortar. And a calibrating step of flattening the rolled steel sheet subjected to the rolling process by passing through a calibrating device along a progress line, wherein the calibrating process includes a calibrating roll including a first roll and a second roll having different diameters, Wherein the first roll and the second roll are vertically arranged to form a set and a plurality of sets are alternately arranged vertically and spaced apart along the progress line in accordance with a calibration device The rolled steel sheet is advanced so that the rolled steel sheet passes through the first roll and the second roll of each set one by one,
Wherein the diameter of the back-up roll supporting the calibrating roll is formed to have a diameter equal to or larger than the D2 value satisfying I > I 'in the following formula (1).
Equation (1)
I = ((dd14 / 64) + (d12 / 4) d32) + d12 / 64) +
I '= ((? D 14/64) + (? D 12/4) D 32) + (? D 24/64) +? D 22/4 D 22/4)
D1 = calibration roll diameter in the above calibration device,
D2 = backup roll diameter in said calibrating device,
D3 = distance from the reference axis in the calibration device to the center of the calibration roll,
d1 = calibrated roll diameter in the calibrating device shown in Fig. 4 with the same size of the upper and lower calibrating rolls,
d2 = back-up roll diameter in the calibrating device shown in Fig. 4 with the same size of the upper and lower calibrating rolls,
d3 = the distance from the reference axis to the center of the calibrating roll in the calibrating apparatus shown in Fig. 4 with the same size of the upper and lower calibrating rolls.

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