JPH11347629A - Straightening and cooling device for high temperature steel plate and its straightening and cooling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a cooling technique, wherein a gradient of heat flux on the surface of a steel plate becomes positive with respect to temperature by combining straightening after rolling to water cooling and moreover a temperature history of each corresponding section of the upper and lower surfaces becomes the same in on-line of a hot rolling and manufacturing process of the steel plate, with a simple structure and inexpensive equipment. SOLUTION: In a straightening and cooling device for a hot temperature steel plate wherein the steel plate is transported with plural upper and lower roll pairs 6a while cooling water being drained in a first straightening after rolling, water cooling 4 and a second straightening processes, the first straightening is executed using a multiple type simple leveler having five rolls or more, a crown is applied to the leveling roll, a steel plate guide mechanism in the width direction is provided before the first straightening, the number of injecting row which is formed by jetting cooling water from nozzle hole rows 8 and slits 10 aligned in the width direction is increased in the lower surface side more than in the upper surface side of the plate, moreover a position in the longitudinal direction of collision starting of cooling water against the surface of the plate between each roll is set to coincide with in the upper and lower surfaces, and leaked water on the upper surface of the plate wherein draining by the roll is incomplete is blown away from the plate side end part to the opposite side end part. A nozzle type is specified to a slit, a spray, a round tube laminar nozzle, a round tube jet stream with a conduit or a perforated plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to on-line cooling of a hot-rolled high-temperature steel sheet, in which the distortion of the hot-rolled high-temperature steel sheet is corrected, uniformly cooled, and corrected again to produce a flat steel sheet. For straightening and cooling a high-temperature steel sheet, and a method for straightening and cooling the same.

[0002]

2. Description of the Related Art In recent years, in controlled rolling, which combines cooling and rolling of a high-temperature steel sheet, and in controlled cooling, in which the high-temperature steel sheet is cooled on-line, high-precision temperature control, especially the cooling stop temperature, has been accompanied by the improvement of products. Control is being performed.

[0003] In general, a hot-rolled high-temperature steel sheet is likely to have cooling unevenness during cooling due to a difference in temperature distribution, shape or surface state of the steel sheet immediately after rolling. Further, uneven cooling of the steel sheet is likely to occur due to the performance of the cooling device. Then, when cooling unevenness occurs in the steel sheet, deformation, residual stress, material variation and the like of the steel sheet occur after cooling. In particular, when cooling a hot-rolled thick steel plate online, cooling of the upper and lower surfaces of the steel plate is difficult to be performed vertically and symmetrically. And other operational problems. In addition, the steel sheet deformed in this way is used in a later process.
It requires costly refining processing by a press and a straightening machine, which increases the cost.

Therefore, in order to eliminate the uneven cooling of the steel sheet, a method of uniformly cooling the steel sheet has been proposed, and a method of straightening the steel sheet prior to cooling, and a method of straightening the steel sheet again after cooling. Proposed.

In order to achieve uniform cooling and flattening of such a steel sheet, the following matters are important: 1. In the cooling device, completely drain the cooling water after cooling, and quickly remove residual cooling water from the steel sheet. 2. The steel plate to be sent to the cooling device should be in a state of small distortion. 3. The cooling of the steel sheet in the cooling device is performed such that the steel sheet is always cooled from a higher temperature portion and the temperature histories at the corresponding portions on the upper and lower surfaces of the steel sheet are the same; The steel sheet sent out from the cooling device must be straightened immediately to the required flat shape.

[0006] When cooling a high-temperature steel sheet by an on-line type in the manufacturing process, a so-called on-line cooling apparatus is provided immediately after the hot steel sheet rolling apparatus. As the on-line cooling device, a device that is arranged and configured in the order of the straightening device, the cooling device, and the straightening device along the flow of the steel sheet is preferable. For example, the following technology is disclosed.

[0007] A first hot leveler provided immediately after a hot rolling mill, a steel plate cooling device provided immediately after the leveler,
A technique for obtaining a flat steel sheet using a series of devices including a second hot leveler provided immediately after the cooling device is disclosed (hereinafter referred to as Prior Art 1).

Next, as a cooling device, a system is generally used in which a steel sheet is cooled by injecting cooling water between the rolls while passing the steel sheet through a plurality of sets of rolls provided at required intervals. That is, a cooling zone is formed by providing a steel plate cooling mechanism between the rolls, and each roll has a function of a draining roll for blocking cooling water on the upper surface of the steel plate (hereinafter, referred to as a constrained roll).

[0009] In cooling the steel sheet using the above cooling device, in particular, a thick steel sheet has a large product size, a sheet width of 5 m, and a large sheet thickness. Therefore, a large amount of cooling water is used to cool the steel sheet. I do. How to block such a large amount of cooling water at the end of each cooling zone to drain water, and how to quickly flow and separate this blocked water from the side end of the steel sheet, This is an important issue from the viewpoint of distortion prevention and cooling stop temperature control.

[0010] On the other hand, various researches have been made on a steel plate drainer. For example, the following technology has been proposed. No. 53-39508 gazette The air nozzle is vertically arranged toward the upper surface of the steel plate.
There is disclosed a method of draining the upper surface of a steel plate by jetting air (hereinafter referred to as prior art 2).

[0011] A water jet nozzle is provided at one side end of a steel sheet transferred on a table roller, from which high-pressure spray water is jetted in the width direction of the steel sheet and stays on the steel sheet. There is disclosed a method of removing remaining water from the other side end of the steel sheet (hereinafter referred to as Prior Art 3).

Japanese Unexamined Utility Model Publication No. 58-125611 and Japanese Unexamined Utility Model Application Publication No. 59-161062 discloses a method of draining a steel sheet by pressing the steel sheet with rubber lining rolls provided vertically above and below the steel sheet. , Referred to as Prior Art 4).

Japanese Patent Laid-Open Publication No. Sho 60-206516 and Japanese Utility Model Laid-Open Publication No. Hei 7-33406 A draining roll is arranged, and a water jet nozzle is provided at a central portion in the width direction of the plate on the outlet side thereof. And a method of injecting water toward a draining roll to drain the water (hereinafter referred to as Prior Art 5).

Further, a technique has been proposed in which, during cooling of a steel sheet in a cooling device, the temperature histories at respective parts of the steel sheet are made as equal as possible at corresponding positions on the upper and lower surfaces. For example, the following technology is disclosed.

When cooling a steel plate by passing it through two cooling devices on-line, the first cooling device injects cooling water from upper and lower slit nozzles and cools the second steel plate. As a cooling device, a device for cooling a thick steel plate by injecting cooling water from a spray nozzle is disclosed (hereinafter referred to as Prior Art 6).

Japanese Patent Application Laid-Open No. 61-264137 discloses a method of cooling by injecting cooling water from a slit nozzle provided above and below a steel sheet at an angle of 15 to 25 ° to the steel sheet (hereinafter referred to as cooling). , Referred to as Prior Art 7).

JP-A-59-144513 discloses a method in which two pairs of nozzles are provided above and below a steel sheet and opposed to each other, and cooling water is injected from the nozzles to cool the steel sheet. , Referred to as prior art 8).

The upper cooling nozzle is a slit nozzle that is long in the width direction of the sheet, is provided near the outlet side of the upstream roll, and injects cooling water in the traveling direction along the surface of the steel sheet. . The top side cooling water is
Water is absorbed near the downstream roll. On the other hand, the lower nozzle is also a slit nozzle similar to the upper nozzle, but a method is disclosed which is provided at the center between the rolls and injects cooling water toward the lower surface of the steel sheet (hereinafter referred to as prior art 9).

[0019]

(1) According to Prior Art 1, when a hot steel sheet after rolling is uniformly cooled to produce a flat steel sheet, internal stress due to rolling distortion is reduced by a first hot leveler. The second hot leveler is advantageous in that the internal stress caused by the cooling strain that is subsequently generated is released by the second hot leveler. However, as for the cooling device for the steel sheet and the two hot levelers, only those commonly used are used. Accordingly, a relatively large cooling distortion is generated, so that a second hot leveler having a large load is required, and the equipment cost is increased.

(2) With respect to the conventional cooling water draining and cooling residual water removal, as in the prior art 2, a method of arranging an air nozzle freely on the upper surface of the steel plate and draining with blast air, or as in the prior art 3. In the method of spraying high-pressure spray water from the side end of the steel sheet to remove the residual water of the cooling water remaining on the upper surface of the steel sheet, a large amount of cooling water flows in the case of a wide thick steel sheet, It is difficult to stop this in a non-contact state and push it to the side end of the steel sheet to remove it. Prior art 4
According to the method of draining by draining with a rubber lining roll, or by spraying water from the center of the width of the plate on the exit side of the draining roll of the prior art 5 to both end portions of the plate and the draining roll, water leakage can be eliminated. Although the effect should be achieved to some extent, it is difficult to eliminate the cooling water flowing out from the gap between the steel sheet and the draining roll because the steel sheet is considerably distorted during the implementation. It is difficult to control with accuracy.

(3) Regarding the uniform cooling performance of the steel plate of the cooling device, a technique of injecting cooling water into the steel plate so that the temperature histories at the respective parts of the steel plate during cooling become the same at the symmetrical position of the upper and lower surfaces is important. .

In this regard, it is difficult to adjust the amount of cooling water to be injected as described above by any of the prior arts 6 to 8, and in particular, because of the distortion and stress generated in the steel sheet during cooling, There was a problem that the steel plate was deformed during or after cooling. That is, on the upper surface of the high-temperature steel plate, in addition to the cooling by the jet of the cooling water colliding with the steel plate, there is also the cooling by the stagnant water after the collision flowing on the upper surface of the steel plate. On the other hand, on the lower surface side of the steel sheet, the cooling water after the collision with the steel sheet immediately separates from the steel sheet due to the effect of gravity, so that only cooling by the collision jet can be expected. Therefore, in the method of cooling the upper and lower surfaces of the steel sheet by the same method, it is not possible to perform vertically symmetric cooling.

Therefore, in general, a method of increasing the flow rate and flow velocity of the cooling water with respect to the lower surface of the steel sheet, or increasing the cooling length of the lower surface, or the cooling amount of the lower surface side of the steel plate and the cooling amount of the upper surface side are used. It has been necessary to make adjustments such as reducing the amount of cooling on the upper surface side so as to make the same.

Furthermore, even if the cooling amounts for the upper and lower surfaces of the steel sheet were the same, there was a clear difference in the cooling distribution in the longitudinal direction of the steel sheet. That is, on the upper surface of the steel sheet, even after the cooling water collides with the steel sheet, the cooling water flows on the surface of the steel sheet, so that the heat flux is uniform in the longitudinal direction of the steel sheet, whereas In this case, the impinging cooling water immediately separated from the lower surface of the steel sheet, so that the heat flux tended to decrease in the longitudinal direction of the steel sheet.

Even if the amount of cooling on the upper and lower surfaces of the steel sheet is the same by means such as increasing the heat flux on the lower surface of the steel plate or lowering the heat flux on the upper surface of the steel plate, depending on the position in the longitudinal direction when viewed locally. It is difficult to say that cooling is always vertically symmetrical, and therefore the temperature histories of the upper and lower surfaces of the steel sheet are not the same. And deformation was inevitable.

In the prior art 9, cooling water is sprayed from a slit nozzle that is long in the plate width direction on both upper and lower surfaces, the upper nozzle is sprayed at the start position of the cooling zone, and the lower nozzle is sprayed at the center of the cooling zone. Therefore, the position of the steel sheet in the conveying direction of the steel sheet at the start of collision between the steel sheet and the cooling water injected from the nozzle is different, and the heat flux after the collision is relatively constant in the longitudinal direction on the upper surface side of the steel sheet. On the underside,
As a result of the intensity of the heat flux in the longitudinal direction, cooling of the upper and lower surfaces is not completely symmetrical, and therefore, the occurrence of distortion is inevitable.

(4) It is an object of the present invention to provide a straightening and cooling apparatus capable of uniformly cooling a hot steel sheet after hot rolling in online cooling to obtain a flat and uniform steel sheet. In order to achieve this purpose, the above (1),
There are the problems described in (2) and (3), and the problems to solve each problem are organized into the following three items.

In order according to the line traveling direction of the steel sheet, the first
In the straightening and cooling device provided with the straightening device, the cooling device, and then the second straightening device, the problem 1. As the first straightening device, a device with a simple structure and low equipment cost was developed, and a device capable of reducing the distortion of the steel sheet to such an extent that the cooling water in the next cooling device can be easily drained was developed. I do.

Task 2. For some reason, for example, when the distortion of the steel sheet immediately after hot rolling is abnormally large, or when the first straightening device cannot suppress the steel sheet distortion to a predetermined value or less due to, for example, wear of the leveling roll crown. For the reason, even if the cooling water is not sufficiently drained by the constraining rolls in the cooling device and the water leaks from the constraining rolls, a device capable of quickly removing the leaked cooling water from the steel plates is developed.

Task 3. As a cooling device, (a) between the heat flux and the temperature on the steel sheet surface, the sign of the heat flux gradient on the steel sheet surface always has the same relationship as the sign of the temperature gradient on the steel sheet surface. A condition in which a portion where the surface temperature is higher than the surroundings is constantly cooled more than a portion where the surface temperature is lower,
Alternatively, (b) a device having a condition capable of cooling such that the temperature histories at the corresponding portions on the upper and lower surfaces of the steel plate are the same is developed.

In the present invention, the object of the present invention is achieved by studying the means for solving the above-mentioned problems, and selectively implementing the means.

[0032]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies from the above-mentioned viewpoints to develop a device for correcting and cooling a high-temperature steel sheet.

(1) First, in connection with the development of a cooling device capable of uniformly cooling a steel sheet, the present inventors have determined that the heat flux on the steel sheet surface in item (a) of the problem 3 is the temperature of the steel sheet surface. A device capable of performing cooling under cooling conditions having a positive gradient with respect to was studied, and the following experiment was performed.

FIG. 3 is a schematic perspective view showing a part of the cooling device used in the experiment. The cooling device 4 includes two vertically arranged cooling devices.
This is a cooling device that performs on-line cooling while conveying the hot rolled steel sheet 1 with 0 sets of constraining rolls 6, and the interval s between the constraining rolls 6 is 1000 mm. Here, each constraining roll 6 has a function of draining the cooling water and a function of transporting the steel sheet 1. Cooling steel sheet 1 between each restraining roll 6 with cooling water
An upper cooling upper nozzle 7 and a lower cooling nozzle 8 for cooling the cooling water are provided.

The upper cooling nozzle 7 is provided on the upper surface of the steel sheet between the constraining rolls 6 and immediately after the constraining roll, and injects cooling water from the constraining roll to a constraining roll adjacent to the downstream side. A slit nozzle 10 was used as a nozzle to be used, and 2000 l / min · m was obtained from the slit nozzle 10 in which the slit length direction was arranged in parallel with the plate width direction.
Flowing a ^second cooling water along the surface of the steel sheet.

On the other hand, the lower cooling nozzle 8
The nozzle rows arranged at a pitch of 100 mm on a straight line parallel to the plate width direction were provided at five positions where the interval between the constrained rolls was divided into six. Cooling water is jetted upward from the five rows of nozzles thus provided. The type of each nozzle constituting the nozzle row is a circular pipe jet nozzle with a conduit. this is,
A pipe with the inner diameter larger than the outer diameter of the pipe nozzle is placed just above the pipe nozzle, and the upper end of the pipe is immersed in the cooling water supplied to a sufficiently large amount in a separately prepared container. (See reference numeral 13 in FIG. 7). When the cooling water is injected from the circular pipe, the liquid flow of the cooling water generated by the accompanying flow collides with the lower surface of the steel plate and cools the steel plate. The cooling water volume density on the lower surface side was 1000 liter / min · m ² .

A static cooling experiment was conducted in which a hot steel plate having a steepness of 2 μm in the shape of the ear wave was caught between the restraining rolls 6 of the cooling device 4 and the conveyance of the steel plate was stopped. Was. As a result, the water flow on the upper surface flowed along the shape of the steel sheet, and the temperature distribution of the steel sheet after cooling was uniform. It has been found that the use of such a cooling device does not disturb the shape of the hot steel sheet before cooling any more.

(2) Next, in connection with the degree of drainage of the cooling water draining roll of the problem 1, the present inventors conducted the following experiment and analysis and studied in detail. First, a cold steel plate having the same thickness as an actual production thick steel plate and having no distortion is successively bitten by a plurality of sets of restraining rolls, and water is poured into the steel sheet between the restraining rolls while passing through. The drainage condition of the steel plate was tested. As a result, as expected, it was found that drainage was completely performed even when a simple steel roll was used as the restraining roll. Thus, if there is no distortion in the steel sheet, the constraining roll does not rise from the steel sheet.

Next, a predetermined strain was applied to the steel sheet in advance, and the steel sheet was passed through a cooling device to test the state of drainage. The pressing force of the restraining roll was 5t. As a result, depending on the thickness of the steel sheet and the magnitude of the strain, it was found that draining was performed well or draining was poor.

FIG. 20 shows this state. FIG. 4 is a graph showing the relationship between the steepness of the ear wave shape of the steel plate and the goodness / badness of the water drainage property when the plate thickness is 10 mm, 20 mm, and 30 mm. However, when the wave height of the ear wave is A and the pitch of the ear wave is B, the steepness α = (A / B) × 100 (%) ---------------- ( 1) Indicated by. As can be seen from FIG. 20, when the steel sheet distortion is small, the drainage property is good, but when the distortion exceeds a certain level, the drainage property is deteriorated, and both good and defective are mixed (in the hatched area in FIG. 20). ). When the distortion is further increased, the drainage property is always poor. And, as the plate thickness increases, the upper limit strain at which good drainage properties can be obtained decreases. However, the influence of the strain on the good / bad drainability varies depending on the magnitude of the restraining force of the restraining roll.

As described above, if the distortion of the steel sheet is reduced to a predetermined value or less by the first straightening device and then sent to the next cooling device, the cooling water is drained well by the constraining rolls in the cooling device. be able to. However, here, the required value of the distortion of the steel sheet before entering the cooling device is determined according to the performance specifications of the constraining roll of the cooling device, particularly the restraining force of the constraining roll, and the thickness and width of the steel sheet. .

Since the present inventors have obtained the above knowledge, the present inventors have completed the development of a drainer which is insufficiently effective at present and will not adopt the step of providing the drainer in the cooling device of the present invention.

FIG. 20 shows the distortion of the steel sheet before entering the cooling device.
As shown in (1), a hot leveler device having a simple structure capable of repeatedly bending is suitable as a straightening device for keeping the required value below a required value. In general, a hot leveler, which is widely used for online shape correction of steel plate manufacturing, requires a huge construction cost of about 1 billion yen or more per unit. However, in this invention, the hot leveler as the first straightening device installed on the inlet side of the cooling device in order to make the cooling of the steel sheet uniform is sufficient if it is a double type and has five or more rolls. Reach the purpose However, in the double type leveler, the bending of the roll has an adverse effect on the shape of the steel plate, and cannot be used as a normal thick steel plate leveler.
If the roll diameter is increased to 350 mm or more, it is possible to correct a steel sheet having a thickness of 15 mm or less, in which the shape of the steel sheet is easily disturbed, to a shape that can ensure drainage.

That is, at the time of correcting the shape of the steel sheet, the leveling roll bends due to the correction load. Table 1
Shows the results.

[0045]

[Table 1]

As can be seen from this, the deflection of the leveling roll at the time of correcting the shape of the steel sheet increases as the sheet width increases and as the sheet thickness increases. Therefore, when a deflection τ (mm) occurs in the leveling roll due to the straightening load, the steel sheet is straightened by the leveled roll in the bent state, and the steepness α of the ear wave remaining on the steel sheet coming out of the straightening device ( %). On the other hand, according to FIG.
Since the allowable upper limit of the ear wave steepness of draining becomes good by constraining rolls of the cooling apparatus of the next step α _{U, Lim} (%) are required, allowable upper limit of the steepness α _{U, Lim} (% ), The deflection τ _{U, Lim} (mm) of the leveling roll at the time of correcting the shape of the steel sheet can be obtained. Thus, the upper limit value τ _{U, Lim} (mm) of the deflection of the leveling roll at which the drainage property by the constraining roll becomes good was determined according to the combination of the width and thickness of the steel sheet. According to this result, in Table 1 above, a result was obtained that, as long as the high-temperature steel plate had a plate width and a plate thickness above the double line, the drainage by the constraining roll was good. In Table 1, the diameter of the leveling roll is 350 mm, and the length of the leveling roll is 47 mm.
In this case, a hot leveler having a corrective force capable of sufficiently securing drainage is obtained.

Further, if the leveling roll is crowned to compensate for the deflection, good drainage can be obtained up to a range where the plate thickness is larger, and the applicable range is expanded.
Table 2 shows the amount of deflection of the leveling roll when a crowned leveling roll was used under the same conditions as in Table 1.

[0048]

[Table 2]

The crown shape is designed such that the curved shape of the roll surface in the roll body length direction corresponds to a half wavelength of the sine function.
The diameter at the center of the trunk length is 350.8 mm). Board thickness 25m
When it is less than m, good drainage properties are ensured in almost all sheet widths, and a range capable of coping with shape defects (strain and warpage) caused by rolling is expanded.

The deflections of the leveling rolls in Tables 1 and 2 are indicated by the maximum value of the deflection generated by a double hot leveler having five or more leveling rolls. Based on the various findings described above, an apparatus and a method for straightening and cooling a high-temperature steel sheet have been configured as follows.

First, the invention relating to the apparatus will be described. The invention according to claim 1 is based on the knowledge described in the above (1) and (2), and the device for correcting and cooling a high-temperature steel sheet removes a shape defect of a hot-rolled high-temperature steel sheet. A first straightening device for straightening before cooling of the steel plate, and installed on the outlet side of the straightening device, and one each for up and down
The high-temperature steel sheet is conveyed while being engaged with a plurality of sets of constraining rolls formed by rolls arranged one by one, and cooling water is injected between upper and lower surfaces of the high-temperature steel sheet between the constraining rolls to cool the steel sheet. And a second straightening device installed on the outlet side of the cooling device and correcting the shape defect of the steel plate cooled by the cooling device. In the above, the first
Is characterized in that the correction device has the configuration of the following item (a). (A) The method of the first straightening device is a hot leveler, and the hot leveler has a roll number of five or more, and a type of a pressing / driving mechanism of the hot leveler is a double type or more multiple structure. thing.

The invention according to claim 2 is based on the findings described in the above items (1) and (2), and the leveling roll according to the invention (a) according to the item (1) is as follows: It is characterized by having the configuration of b). (B) The leveling roll of the hot leveler is crowned.

(3) The present inventors further conducted the following experiment on the drainage of the cooling water by the roll of the problem 1.
Using the apparatus used in the experiment of (1) above, a steel sheet guide is provided on the entry side of the first straightening apparatus in accordance with the experimental method of (2), and the width center line of the hot steel sheet after rolling is corrected. Aligned to the width centerline of the device. Then, after correcting by a leveling roll, it was sent to a cooling device. The restraining force of the restraining roll in the cooling device was set to 5 t. And the drainage property and steepness of the cooling water of the steel plate were measured.

As a result, the distribution of the steepness of the steel sheet is reduced by using the steel sheet guide so that the width of the steel sheet is matched with the center of the leveling roll width of the straightening machine as compared with the case where the steel sheet guide is not used. Was done. Furthermore, by the centering operation of the width of the steel plate by the steel plate guide,
The biting state of the steel sheet in the constraining roll of the cooling device is also centered in the width direction. As a result, the drainage by the constraining rolls was significantly dependent on the steepness of the steel sheet before entering the cooling device. And FIG.
However, even if the steepness is at the same level as in the above, there are mixed regions where the drainage is good or poor, and the drainage is stable.

No special function is required for the structure of the steel sheet guide for the purpose of positioning the steel sheet in the width direction. However, the installation location is provided immediately before the first straightening device, and if the width center line of the steel plate is aligned with the width center line of the straightening device by the guide, the steel plate is restrained by the straightening device. The cooling device is also advantageous because the width center line of the steel plate coincides with the width center line.

The invention according to claim 3 is obtained by adding the knowledge of item (3) to the knowledge described in items (1) and (2) above. The cooling device according to the first or second aspect of the present invention is characterized in that the first straightening device has the following configuration (c). (C) A guide mechanism for a high-temperature steel plate is provided on the entry side of the first straightening device so as to align the center line of the width of the high-temperature steel plate with the center line of the width of the straightening device.

(4) If both the first straightening device and the cooling device have the above-described configurations, the cooling water flows from the gap formed between the draining roll, which is the restraining roll, and the steel plate. Even if it leaks, the amount is small and practically does not hinder the uniform cooling of the steel sheet and the control of the cooling stop temperature.
However, for example, when the cooling imbalance or the shape correction before the cooling device becomes insufficient, a gap is generated between the drain roll and the steel plate. In this case, if the leaked cooling water is not promptly removed from the upper surface of the steel sheet, the water leaks non-uniformly in the non-cooled zone.

Therefore, as a mechanism for quickly removing the water leakage from the draining roll of the problem 2 from the steel sheet, immediately after the exit side of the constraining roll, high-pressure water is applied from one end of the steel sheet side to the other side of the steel sheet. It was expected that the above-mentioned water leakage could be promptly removed from the surface of the steel sheet if the jet was sprayed so as to slide.

The invention according to claim 4 provides the above (1) to (4).
The knowledge of (3) is further added to the knowledge of (4), and the device for correcting and cooling a high-temperature steel plate is provided in the invention according to claim 1, 2, or 3. The cooling device is characterized by having the following configuration (d). (D) on the exit side of each of a plurality of sets of restraining rolls of the cooling device,
A fluid ejecting mechanism for forming a jet fluid from one side end of the upper surface of the steel plate toward the other side end is provided.

(5) Next, in connection with the development of a cooling device capable of uniformly cooling the steel sheet, the present inventors have determined that the upper and lower surfaces of the steel sheet corresponding to item (b) of the problem 3 should be dealt with. The following study was conducted to develop a device that can perform cooling under conditions that allow cooling so that the temperature histories at each part become the same.

FIG. 22 shows the thermal histories of the front and back surfaces of the steel sheet when the cooling water was sprayed from the slit jet nozzle onto the upper and lower surfaces of the steel sheet immediately after rolling, using the finite element method. FIG. 23 is a graph showing the results obtained by plastic analysis, and FIG. 23 shows the change with time of the C warp amount δ (mm), which is the warp in the width direction of the steel sheet at that time, obtained by thermo-elasto-plastic analysis by the finite element method. 9 is a graph showing the results.

As is apparent from FIGS. 22 and 23,
Due to the difference between the overall heat transfer coefficient for the upper surface of the steel sheet and the overall heat transfer coefficient for the lower surface, residual C warpage occurs in the steel sheet even when the upper and lower surfaces have the same cooling end temperature. In order to avoid this, not only the cooling amount of the entire cooling zone but also the cooling heat flux during the cooling needs to be kept the same on the upper and lower surfaces of the steel sheet.

FIG. 24 is a schematic diagram showing a normal contact state of the cooling water on the upper and lower surfaces of the steel plate. Here, the steel sheet 1 conveyed online is noted. As shown in FIG. 24, the position at which the cooling water starts to contact the upper surface of the steel sheet 1 after passing through the preceding constraining roll 6 is the position of the straight line p,
The position where the cooling water starts to contact the lower surface is the position of the straight line q. As described above, if the position in the longitudinal direction of the steel sheet at which the cooling water starts to contact the upper and lower surfaces of the steel sheet is not the same, the C-warp of the steel sheet whose cross-sectional shape in the width direction of the steel sheet is convexly curved upward or downward may occur. It was found by thermo-elasto-plastic analysis by finite element method. FIG. 25 shows the result.

FIG. 25 shows the positions at which the upper and lower surfaces of the steel plate start contacting the cooling water, p and q, respectively, and the coordinate axes of the contact start position in the steel plate conveying direction are taken, and the difference y and C between p and q are plotted. 6 is a graph illustrating an example of a relationship with a warp amount δ. As can be seen from the figure, the larger the absolute value of y, the sharper the absolute value of δ. As described above, the displacement of the upper and lower surfaces of the steel sheet surface in the conveyance direction of the steel sheet at the start of contact between the cooling water injected from the nozzle and the steel sheet surface has a great effect on the C warpage of the steel sheet. However, it has been found that if the deviation y is equal to or less than a predetermined value, the C warpage of the steel sheet does not practically occur.

The inventors of the present invention have already studied the uniform cooling of the steel sheet in the above item (1), and have found out about the desirable condition of the heat flux with respect to the temperature distribution of the steel sheet surface which is the item (a) of the problem 3. Have gained. In addition, the cooling water at the lower part of the steel sheet immediately departs from the steel sheet due to the influence of gravity after colliding with the steel sheet. Therefore, unless the number of upper cooling nozzles is greater than the number of lower cooling nozzles, the upper and lower surfaces of the steel plate cannot be cooled symmetrically.

The invention according to claim 5 is obtained by adding the knowledge in this paragraph (5) to the knowledge in the above paragraph (1). The device for correcting and cooling a high-temperature steel plate has the following features. It has. That is, a first straightening device for correcting a shape defect of a hot-rolled high-temperature steel plate before cooling the steel plate, and a first straightening device installed on an outlet side of the first straightening device, and one each for upper and lower portions. In order to cool the steel sheet by injecting cooling water between the constraining rolls onto the upper and lower surfaces of the high-temperature steel sheet while conveying the high-temperature steel sheet while being engaged with a plurality of sets of the constraining rolls formed by one set of rolls. A cooling device, and a straightening and cooling device for a high-temperature steel plate, which is installed on the outlet side of the cooling device, and comprises a second straightening device for correcting a shape defect of the steel plate cooled by the cooling device, The cooling device is characterized by having the following configurations (e) and (f). (E) The cooling device is provided with an upper cooling nozzle and a lower cooling nozzle for injecting cooling water toward the upper surface and the lower surface of the steel plate, respectively. Both the upper cooling nozzle and the lower cooling nozzle are long nozzles in the width direction of the steel sheet so that the aging change of the temperature and the aging change of the temperature at each minute portion on the lower surface are the same with the steel sheet thickness center plane as the symmetry plane. Forming a row, the number of nozzle rows whose lower cooling nozzle rows are arranged in the steel sheet length direction, that the upper cooling nozzles are installed more than the number of nozzle rows arranged in the steel sheet length direction, And (f) in any cooling zone in which the steel sheet is injected with cooling water between the constraining rolls, the arrangement of the upper cooling nozzle and the lower cooling nozzle is such that the cooling water injected from the upper cooling nozzle is The position in the longitudinal direction of the steel sheet at which contact with the upper surface of the steel plate starts and the position of the longitudinal direction of the steel plate at which the cooling water injected from the lower cooling nozzle starts contacting the lower surface of the steel plate may be adjusted to be the same. Structure.

(6) In the invention of claims 1 to 4 described above, based on the knowledge that all of the problems 1 to 3 can be solved, in order to configure a more excellent apparatus for correcting and cooling a high-temperature steel sheet,
The invention according to claim 6 is constituted.

The invention according to claim 6 is the invention according to any one of claims 1 to 4, wherein
It is characterized by having the following configurations (e) and (f). (E) The cooling device is provided with an upper cooling nozzle and a lower cooling nozzle for injecting cooling water toward the upper surface and the lower surface of the steel plate, respectively. Both the upper cooling nozzle and the lower cooling nozzle are long nozzles in the width direction of the steel sheet so that the aging change of the temperature and the aging change of the temperature at each minute portion on the lower surface are the same with the steel sheet thickness center plane as the symmetry plane. Forming a row, the number of nozzle rows whose lower cooling nozzle rows are arranged in the steel sheet length direction, that the upper cooling nozzles are installed more than the number of nozzle rows arranged in the steel sheet length direction, And (f) in any cooling zone in which the steel sheet is injected with cooling water between the constraining rolls, the arrangement of the upper cooling nozzle and the lower cooling nozzle is such that the cooling water injected from the upper cooling nozzle is The position in the longitudinal direction of the steel sheet at which contact with the upper surface of the steel plate starts and the position of the longitudinal direction of the steel plate at which the cooling water injected from the lower cooling nozzle starts contacting the lower surface of the steel plate may be adjusted to be the same. Structure.

A seventh aspect of the present invention is characterized in that, in the sixth aspect of the present invention, the cooling device has the following configuration (g). (G) The upper cooling nozzle of the cooling device is constituted by a single row of slit nozzles, and the lower cooling nozzle is constituted by a plurality of rows of nozzles. , A circular pipe laminar nozzle, a circular pipe jet nozzle with a conduit, or a perforated plate nozzle.

Next, an invention relating to a method for straightening and cooling a high-temperature steel sheet will be described. The invention of claim 8 is a method invention corresponding to the invention of claim 1, and is as follows. That is, in the process of manufacturing a steel sheet by hot rolling, the shape of the steel sheet is hot straightened by a first straightening device, then cooled by a cooling device, and then straightened by a second straightening device. The method for straightening and cooling a high-temperature steel sheet has the following features. The straightening of the high-temperature steel sheet by the first straightening device is performed by using a five or more continuous leveling rolls by a double-type or more multi-layer structure pressing / driving mechanism, and the cooling of the high-temperature steel plate by the cooling device is performed by: A method in which cooling water is injected into the upper and lower surfaces of the high-temperature steel sheet between the constraining rolls while the high-temperature steel sheet is being conveyed while being engaged with a plurality of sets of constraining rolls, one set of rolls arranged one above each other. It is.

The ninth aspect of the present invention is directed to a method corresponding to the second aspect of the present invention, and is as follows. That is,
The present invention according to claim 8 is characterized in that the use of a leveling roll with a crown when straightening a high-temperature steel sheet by the first straightening device is further added.

The tenth aspect of the present invention is a method corresponding to the third aspect of the present invention, and is as follows. That is, in addition to the invention according to claim 8 or 9, when the first straightening device corrects the high-temperature steel plate, the correction is performed after the width center line of the high-temperature steel plate is aligned with the width center line of the correction device. It is characterized by adding the following.

The invention described in claim 11 is a method invention corresponding to the invention in claim 4, and is as follows. That is, in any one of the inventions according to claims 8, 9 and 10, furthermore, as a method of cooling a high-temperature steel sheet by a cooling device, drainage of cooling water by the constraining roll is incomplete. It is characterized in that water leaking to the upper surface of the steel plate on the outlet side is removed by blowing it off with a jet fluid from one side end to the other side end of the steel plate.

The twelfth aspect of the present invention relates to a method corresponding to the fifth aspect of the present invention, and is as follows. That is, in a process of manufacturing a steel sheet by hot rolling online, the shape of the steel sheet is hot-corrected by a first straightening device,
A method for straightening and cooling a hot steel sheet, which is then cooled in a cooling device and then straightened in a second straightening device,
The cooling of the high-temperature steel sheet by the cooling device is performed by engaging a plurality of sets of constraining rolls, one set of rolls arranged one above and another one below, and transporting the high-temperature steel sheet between the constraining rolls. The method is characterized by adding the following step (h) as a method of cooling a high-temperature steel sheet by a cooling device. (H) A long nozzle row is provided in the steel sheet width direction with nozzle openings directed to the upper and lower surfaces of the steel sheet, and cooling water is jetted from the nozzle row. Number, the lower side of the steel sheet is larger than the upper side, and the position in the steel sheet longitudinal direction at which the cooling water jet train starts colliding with the steel sheet between the constraining rolls, the upper and lower surfaces of the steel sheet. In accordance with this, adjustment is made so that the temporal change of the temperature in each minute portion of the upper and lower surfaces of the steel sheet during the cooling process of the steel sheet becomes the same with the center plane of the steel sheet thickness as the symmetry plane.

The invention of claim 13 is an invention of a method corresponding to the invention of claim 6, and is as follows. That is, any one of the inventions according to claims 8, 9, 10 and 11 is characterized in that the following method (h) is further added as a method for cooling a high-temperature steel sheet by a cooling device. It is. (H) A long nozzle row is provided in the width direction of the steel sheet with nozzle openings directed to the upper and lower surfaces of the steel sheet, and cooling water is injected from the nozzle row, and the number of injection rows formed by the cooling water thus injected is formed. The lower surface side of the steel plate is more than the upper surface side, and the upper and lower surfaces of the steel plate coincide with the longitudinal position of the steel plate at which the cooling water injection row starts colliding with the steel plate between the constraining rolls. Then, the time-dependent change of the temperature in each minute portion on the upper and lower surfaces of the steel sheet during the cooling process of the steel sheet is adjusted so that the center plane of the steel sheet thickness is the same as the symmetry plane.

The invention of claim 14 is an invention of a method corresponding to the invention of claim 7, and is as follows. That is, the method according to the thirteenth aspect is characterized in that the following method (i) is added as a method for cooling a high-temperature steel sheet by a cooling device. (I) The jet line of cooling water for cooling the upper surface side of the steel plate is jetted from a single line of slit nozzles, and
The jet line of cooling water for cooling the lower surface side of the steel sheet is jetted from plural rows of nozzles, and the type of plural rows of nozzles is a slit nozzle, a spray nozzle, a circular laminar nozzle, a circular tube with a conduit. It must be jetted from a jet nozzle or a perforated plate nozzle.

[0077]

Next, the present invention will be described with reference to the drawings. (1) First Embodiment FIG. 1 is a schematic explanatory view showing a first embodiment of the device of the present invention. This is a process in which a high-temperature thick steel plate immediately after rolling is cooled online while being transported through a steel plate production line. As shown in FIG. 1, a hot steel sheet 1 is sent from a hot finishing mill 2 to the apparatus of the present invention. The device of the present invention
A first straightening device 3, a cooling device 4, and a second straightening device 5 are provided online on the outlet side of the hot finishing mill 2.

FIG. 2 is a schematic perspective view of the first straightening device 3. The first straightening device 3 is a double or more hot leveler, and has five or more rolls, that is, leveling rolls 3a, and each leveling roll 3a is crowned. This hot leveler is 2
It is a simple type hot leveler. Further, no guide mechanism for the steel plate is provided on the entrance side of the hot leveler.

FIG. 3 is a partial perspective view of a main part of the cooling device according to the first embodiment of the present invention. The cooling device 4 includes a constraining roll 6, an upper cooling nozzle 7, and a lower cooling nozzle 8. As shown in the figure, the constraining rolls 6 form one set of one roll pair each of an upper roll 6a and a lower roll 6b, and a plurality of sets are provided at a predetermined pitch in the traveling direction L of the steel sheet.
The constraining roll 6 has a function of transporting the steel sheet during cooling and a function of draining the cooling water. The lower roll 6b is a fixed type, and the upper roll 6a is a movable type having a vertical control mechanism with a predetermined pitch in the vertical direction. When the thickness of the steel sheet is equal to or greater than a predetermined gap between the upper and lower rolls, when the steel sheet is bitten into the roll, a suppressing force acts on both ends of the upper roll 6a via the hydraulic cylinder 9, and the upper and lower rolls are used to hold the steel sheet. It has a structure to restrain.

The cooling zones of the steel sheet are as follows. Between the adjacent constraint rolls 6, an upper cooling nozzle 7 and a lower cooling nozzle 8 are provided above and below the steel sheet passing level, respectively, toward the upper and lower surfaces of the steel sheet.
Thus, the space between the adjacent constraint rolls 6 forms a zone where the steel sheet can be cooled. However, the space may be a non-cooling zone in which the steel sheet is not cooled according to the target value of the steel sheet cooling rate.

As shown in FIG. 3, the upper cooling nozzle 7 is located downstream of each upper roll 6a, that is, on the outlet side, close to the upper roll 6a, and at a location close to the upper surface of the steel plate. The nozzle type is a slit nozzle 10 that is long in the plate width direction and covers the entire plate width. Then, the cooling water is jetted from the upstream side (indicating the direction of the line where the hot finishing mill 2 is installed) in the traveling direction of the steel sheet to the downstream side.

On the other hand, various types suitable for the lower cooling nozzle will be described. In the first mode of the lower cooling nozzle 8, a plurality of nozzle holes are arranged in a straight line at predetermined intervals in the plate width direction in the cooling zone to form a single nozzle row, The rows are provided such that the entire length in the longitudinal direction of the cooling zone is divided into a plurality of sections at predetermined intervals.

The second mode of the lower cooling nozzle 8 is as described in the first embodiment.
The upper cooling nozzle 7 corresponds to the nozzle row of the row.
In this case, a slit nozzle is formed which is long in the plate width direction and covers the entire plate width.

FIG. 4 is a schematic longitudinal sectional view for explaining a second embodiment of the lower cooling nozzle. Multiple slit nozzles 1
Rows 0 are provided in such a manner that the entire length in the longitudinal direction of the cooling zone is divided into a plurality of sections at predetermined intervals.

The manner in which the cooling water is ejected from the nozzle holes in the lower cooling nozzle of the first embodiment will be described in detail. As with the cooling performance of the upper cooling nozzle, the lower cooling nozzle needs to be able to cool the lower surface of the steel plate as uniformly as possible. Therefore, similarly to the slit nozzle of the lower cooling nozzle of the second embodiment, it is necessary to make the cooling water contact as uniformly as possible in the plate width direction. As a nozzle type for that, for example, spray nozzle,
A tube laminar nozzle, a circular tube jet nozzle with a conduit, or a nozzle array in which perforated plate nozzles are arranged so as to cover the entire plate width at a relatively short pitch in the plate width direction are suitable.

Each of FIGS. 5, 6, 7 and 8
A spray nozzle, a circular pipe laminar nozzle, a circular pipe jet nozzle with a conduit, and a perforated plate nozzle as a lower cooling nozzle,
Between adjacent constraining rolls, the situation where it is installed as a plurality of nozzle rows, and the outer shape of the injection cooling water will be described macro-
It is a schematic longitudinal cross-sectional view. Here, a single row of slit nozzles 10 is provided as the upper cooling nozzle 7. Each cooling nozzle will be further described.

In the case of the spray nozzle shown in FIG. 5, the nozzle rows of the spray nozzles 11 arranged in a straight line at a predetermined pitch in the width direction of the plate are eight rows perpendicular to the longitudinal direction L of the plate at predetermined intervals. It is a case where it is provided. Adjusting the spray nozzle design and use conditions, such as the nozzle hole pitch in the plate width direction and the plate longitudinal direction of the lower surface of the steel plate, the distance between the tip of the nozzle hole and the lower surface of the steel plate, the spray angle of spray water, or the water pressure, etc. The cooling water is adjusted so that the cooling water is sprayed uniformly in both directions in the plate longitudinal direction.

In the case of the circular laminar nozzle shown in FIG. 6, seven nozzle rows of circular laminar nozzles 12 arranged in a straight line at a predetermined pitch in the width direction of the plate have a predetermined number of lines at right angles to the longitudinal direction L of the plate. This is a case where they are provided at intervals.
According to the spray nozzle described above, the nozzle pitch in the plate width direction and the plate longitudinal direction, the distance between the tip of the nozzle hole and the lower surface of the steel plate, the cross-sectional hole diameter of the tube laminar nozzle, or the water pressure, etc. By adjusting the design and use conditions, the cooling water is adjusted so that the cooling water is sprayed uniformly in both the width direction and the length direction of the lower surface of the steel sheet.

However, the circular tube laminar nozzle in the present invention refers to a nozzle having a function of supplying a continuous fluid which is practically circular in cross section of a water flow to be jetted from the nozzle and has no turbulence.

In the case of the circular pipe jet nozzle with a conduit shown in FIG. 7, the nozzle row of circular pipe nozzles 13a arranged in a straight line at a predetermined pitch in the width direction of the plate is formed by five nozzles at right angles to the longitudinal direction L of the plate.
The columns are provided at predetermined intervals. Immediately above each of the circular nozzles 13a, a circular conduit 13b having an inner diameter sufficiently larger than the outer diameter of the circular nozzle 13a is provided. And the circular tube nozzle 13a
Is immersed to a predetermined depth below the water surface filled with a container 15 capable of accommodating and supplying a sufficiently large amount of cooling water 14, while the upper end of the conduit 13b is located above the water surface. Then, when the cooling water is injected upward from the circular tube nozzle 13a, the cooling water 14 in the container 15 is injected through the conduit 13a, and an accompanying flow 16 accompanying this injected water is generated. The liquid flow of the accompanying cooling water collides with the lower surface of the steel sheet and cools the steel sheet.

Here, a pair of the circular tube nozzle 13a and the conduit 13b is referred to as a circular tube jet nozzle 13 with a conduit. Also in this case, according to the spray nozzle and the circular tube laminar nozzle, the pitch of the circular tube jet nozzle with the conduit in the plate width direction and the plate longitudinal direction, the distance between the conduit and the distal end of the circular tube nozzle hole and the lower surface of the steel plate, the conduit By adjusting the design and use conditions of the pipe-jet nozzle with conduit, such as the diameter of the pipe nozzle and the diameter of the pipe nozzle, or the jet pressure of the cooling water, it is practically uniform in both the sheet width direction and the sheet longitudinal direction on the lower surface of the steel sheet. It is adjusted so that cooling water is injected.

In the case of the perforated plate nozzle 17, as shown in FIG. 8, a nozzle hole 17d for jetting cooling water is provided in a steel plate constituting the ceiling plate 17b of the cooling water supply container 17a. The cooling water supply container 17a is filled with cooling water of a required pressure supplied from outside.

FIG. 9 is a plan view of the perforated plate nozzle 17 of FIG. 8, and a nozzle 17d is formed in the ceiling plate 17b in the width direction of the steel plate 1 at a predetermined pitch w, for example, w = 100 mm. The hole row 17c has a predetermined interval e, for example, e = 5.
A plurality of rows are provided at 0 mm intervals at right angles to the steel sheet advancing direction L, and the nozzle holes 17d in the adjacent rows are arranged in a staggered manner. Also in this case, according to the spray nozzle, the circular pipe laminar nozzle, or the circular pipe jet nozzle with a conduit, the pitch between the nozzle holes in the plate width direction and the interval between the nozzle hole rows, the distance between the nozzle hole tip and the steel plate lower surface, By adjusting the design and use conditions of the perforated plate nozzle, such as the cross sectional hole diameter of the nozzle hole or the water pressure, the cooling water is sprayed practically uniformly in both the plate width direction and the plate longitudinal direction on the lower surface of the steel plate. Has been adjusted as follows.

A plurality of nozzles, such as a spray nozzle, a circular tube laminar nozzle, a circular tube jet nozzle with a conduit, and a perforated plate nozzle, which are the first form of the above-mentioned lower cooling nozzle, have a predetermined pitch. Form a nozzle row arranged in the plate width direction. The ratio of the number of rows of the upper cooling nozzles and the number of rows of the lower cooling nozzles can be arbitrarily set according to cooling conditions. Reduce the pitch and spacing of the nozzles in a row,
The closer the nozzles are arranged, the less the local non-uniform heat flux. However, the effect is saturated even if it is made too narrow, and on the other hand, from the viewpoint of maintenance and economical efficiency of the nozzle, the denser the nozzle, the more disadvantageous. Further, in the actual equipment, there is a restriction on the space for installing the nozzle mechanism. Therefore, there is a desirable pitch range according to the specific circumstances of the equipment, and therefore the nozzle installation pitch should not be defined uniformly.

Desirable conditions for uniformly cooling the steel sheet are as follows. In each of the cooling zones, the cooling water sprayed from the upper cooling nozzle contacts the upper surface of the steel sheet. And the position at which the cooling water injected from the lower cooling nozzle starts to contact the lower surface of the steel plate can be adjusted to be the same. The reason is that, as described in the section (5) of the means for solving the problem, the magnitude of the deviation y of the position in the steel sheet transport direction at which the upper and lower surfaces of the steel sheet start contacting the cooling water is equal to the steel sheet. This has a large effect on the magnitude of the C warpage amount δ. If the deviation y is equal to or less than a predetermined value, practically no C warpage of the steel sheet occurs, and it is more desirable that the deviation y is substantially 0. It is.

(2) Embodiment 2 A second embodiment of the apparatus of the present invention is the same as the first embodiment, except that a steel plate guide mechanism is provided on the entrance side of the first straightening device. The details will be described below.

FIG. 10 is a schematic longitudinal sectional view for explaining a second embodiment of the device of the present invention. In the drawing, reference numeral 18 denotes a guide mechanism, which is provided immediately before the first straightening device 3 to center the steel sheet in the width direction before loading the high-temperature steel sheet into the first straightening device 3. I have.

FIG. 11 is a partial perspective view of a main part of the first straightening device 3 and the cooling device 4 in the second embodiment of the present invention. A hot leveler is provided as the first straightening device 3. The system / structure is a double type or higher hot leveler, which has five or more rolls, that is, leveling rolls 3a, and each leveling roll 3a is crowned. This hot leveler is a double-type simple hot leveler. The above is the same as the first embodiment. As an important feature of the second embodiment, a steel sheet guide mechanism 18 is further provided on the entrance side of the hot leveler. The form of the guide may be any of the roll guide 19 and the plate guide, and is not particularly limited.

The cooling device 4 also has the same configuration as that of the first embodiment, and includes a constraining roll 6, an upper cooling nozzle 7, and a lower cooling nozzle 8, and the details of the configuration and functions thereof are the same as those of the first embodiment. is there.

As described above, the second embodiment is added to the first embodiment in that the guide mechanism 18 is provided immediately before the entrance of the first straightening device. Then, the steel plate 1 centered in the width direction by the guide mechanism 18 is sent to the first straightening device 3 and then sent to the cooling device 4 with the width direction of the steel plate centered. In the cooling device, the effect of draining by the roll is further improved.

(3) Embodiment 3 In a third embodiment of the apparatus of the present invention, the fluid injection mechanism for removing water leakage from the constraining roll during cooling of the steel sheet from the upper surface of the steel sheet according to the first embodiment, This is provided in the cooling device. The details will be described below.

FIG. 12 is a schematic longitudinal sectional view for explaining a third embodiment of the device of the present invention. It comprises a first straightening device 3, a cooling device 4 and a second straightening device 5, and no steel plate guide mechanism is provided on the first straightening device entrance side. In the figure, reference numeral 21 denotes a fluid ejection mechanism.

FIG. 13 is a partial perspective view of a main part of a cooling device 4 according to a third embodiment of the present invention. The cooling device 4 includes a constraining roll 6, an upper cooling nozzle 7, and a lower cooling nozzle 8. Immediately after the upper roll 6a exit side of each constraining roll 6, a fluid ejection mechanism 21 is provided on one side end side of each steel plate. The fluid ejecting mechanism 21 has a function of spraying a water ejecting spray nozzle or other fluid at a high speed, and is capable of quickly blowing water from the constraining roll 6 and removing it from the upper surface of the steel sheet. And the like need not be limited.

The function of the fluid ejecting mechanism 21 is as follows.
Is to inject high-pressure fluid toward the remaining cooling water leaked from the constraining roll 6 due to insufficient draining action of the plate, and to quickly remove the leaked water from the other side end of the plate. That is, the fluid ejecting mechanism can promptly remove the leaked cooling water from the upper surface of the steel sheet in a case where distortion that cannot be drained by the constraining roll occurs in the first straightening device 3 or the cooling device 4. Therefore, water is not injected in all of the cooling zones. For example, when water is injected into the steel plate every other zone, the steel plate is supercooled by the fluid injection mechanism due to water leakage from the cooling zone to the non-cooling zone, or Non-uniform cooling can be prevented.

A guide mechanism for steel sheet centering is not provided on the entry side of the first straightening roll. As described above, in the third embodiment, the fluid ejection mechanism 21
However, since the high-speed jet fluid from one side end of the upper surface of the steel plate on the exit side of each constraining roll of the cooling device to the other side end quickly removes the leakage of cooling water from the steel plate, the drainage action by the constraining rolls is reduced. Can be backed up.

(4) Fourth Embodiment FIG. 14 is a schematic explanatory view for explaining a fourth embodiment of the device of the present invention. This is the same as the apparatus of the third embodiment shown in FIG. 12, but further provided with a steel sheet guide mechanism 18 on the entry side of the first straightening device 3. Therefore, according to the device of the fourth embodiment, the use of the guide mechanism 18 improves the drainage of the cooling water by the constraining roll, and further backs up the draining action of the constraining roll by the water jet spray nozzle of the fluid jetting mechanism 21. The effect is added, and the uniform cooling of the steel sheet and the control of the cooling stop temperature are improved.

(5) Fifth Embodiment FIG. 15 is a schematic explanatory view for explaining a fifth embodiment of the device of the present invention. This is because the hot steel plate just after rolling
This is a process that is cooled on-line while being transported through the steel sheet production line. As shown in the figure, a hot steel sheet 1 is sent from a hot finishing mill 2 to the apparatus of the present invention. The apparatus of the present invention includes a first straightening device 3, a cooling device 4, and a second straightening device 5 on-line on the outlet side of the hot finishing mill 2.

Regardless of the type and structure of the first straightening device 3, it may be a commonly used one or a simple hot leveler. At that time, the leveling roll may or may not have a crown. It does not matter whether the steel plate guide on the entry side is required. The cooling device 4 includes a cooling nozzle adjustment mechanism 22.
Is provided. The most important feature of the fifth embodiment is that the cooling nozzle adjustment mechanism is provided.

FIG. 16 is a partial perspective view of a main part of a cooling device 4 according to a fifth embodiment of the present invention. The cooling device 4
Restraining roll 6, upper cooling nozzle 7, and lower cooling nozzle 8
In addition, a cooling nozzle adjustment mechanism 22 is provided. Among these, the configuration and function of the constraining roll 6, and the type and arrangement method of the upper cooling nozzle 7 and the lower cooling nozzle 8 are the same as those in the first embodiment, and the plurality of sets of constraining rolls are used to transport and drain the steel sheet. And the use of an upper and lower roll gap control mechanism, and the setting of predetermined in-row pitch and row spacing of various nozzles.

On the other hand, the cooling nozzle adjusting mechanism 22 attempts to make the position in the plate longitudinal direction where the cooling water injected from the upper and lower cooling nozzles starts to contact the steel plate coincide with the upper surface and the lower surface of the steel plate. The need to adjust the cooling water flow density in accordance with the required cooling conditions changes the starting position of the cooling water contact with the upper surface of the steel sheet, and it is necessary to eliminate this. Thus, the C-warping of the steel sheet is to be eliminated.

As a method of the cooling nozzle adjusting mechanism 22, there are:
First of upper cooling nozzle 7 and / or lower cooling nozzle 8
Attention should be paid to the cooling water jetted from the second nozzle row. However, the nozzle positions in the second and subsequent rows are appropriately adjusted according to the set positions of the nozzles in the first row. From this viewpoint, a mechanism for moving and adjusting the position of the nozzle hole or the slit of the nozzle, and therefore, a method for moving and adjusting the entire nozzle in the first row. A method for adjusting the injection angle of the nozzle hole or the slit injection angle of the nozzle. There are various methods, such as a method of adjusting the injection speed of the above (however, the cooling water flow density is maintained at a predetermined value or more), and there is no particular limitation.

In the fifth embodiment, the number of the nozzle rows of the lower cooling nozzle 8 parallel to the plate width direction is further changed to the number of the slit nozzles 10 of the upper cooling nozzle 7 (one row parallel to the plate width direction). Install more than That is, at least a plurality of rows of the lower cooling nozzles are provided.

By operating the cooling nozzle adjustment mechanism 22 under the above conditions, the C warpage of the steel sheet generated during cooling is suppressed. Therefore, in the fifth embodiment, the fluid ejection mechanism may not be provided.

(6) Sixth Embodiment FIG. 17 is a schematic explanatory view for explaining a sixth embodiment of the apparatus of the present invention. In this embodiment, a cooling nozzle adjusting mechanism 22 is further provided in the apparatus according to the second embodiment shown in FIG. Therefore, according to the device of the sixth embodiment, the use of the guide mechanism 18 improves the drainage of the cooling water by the constraining rolls, and furthermore, the operation of the cooling nozzle adjusting mechanism 22 causes the cooling jets injected from the upper and lower cooling nozzles. The position in the plate longitudinal direction where water starts to contact the steel plate can be matched between the upper surface and the lower surface of the steel plate. Thus, the uniform cooling of the steel sheet and the control of the cooling stop temperature are improved.

(7) Seventh Embodiment FIG. 18 is a schematic explanatory view for explaining a seventh embodiment of the device of the present invention. This is a device in which a water jet spray nozzle 21 is further provided in the device of the fifth embodiment shown in FIG. Therefore, according to the device of the seventh embodiment, by the operation of the cooling nozzle adjusting mechanism 22, the position in the plate longitudinal direction at which the cooling water injected from the upper and lower cooling nozzles starts to contact the steel plate is different between the upper surface and the lower surface of the steel plate. The cooling water leaked from the constraining roll can be quickly removed from the upper surface of the steel sheet by using the water spray nozzle 21. Thus, the uniform cooling of the steel sheet and the control of the cooling stop temperature are improved.

(8) Eighth Embodiment FIG. 19 is a schematic explanatory view for explaining an eighth embodiment of the device of the present invention. This is a high temperature steel plate 1 just after rolling.
The shape of the steel plate is corrected by the first straightening device 3 provided with the guide mechanism 18 on the entrance side, the number of lower cooling nozzle rows is set to be larger than the number of upper cooling nozzle rows, and the fluid ejection mechanism 21 and the cooling nozzle adjustment mechanism are adjusted. The steel plate is cooled by the cooling device 4 provided with 22 and then corrected by the second straightening device 5.

When the high-temperature steel sheet is straightened and cooled by using the apparatus of the eighth embodiment, the shape of the steel sheet is corrected at the time of loading into the cooling device, the warpage is prevented from being generated during cooling, and the drainage by the restraining roll is performed. In addition, it is possible to perform an operation in which desirable conditions are satisfied from all viewpoints of removing cooling leakage from the confining roll from the upper surface of the steel plate.

(9) In any of the above-described first to eighth embodiments, every other cooling zone may be used or all the cooling zones may be used depending on the target steel sheet cooling rate or the like. It is necessary to use. Further, which embodiment should be adopted depends on the operating conditions of the steel sheet production.

[0119]

Next, the apparatus of the present invention will be described in more detail by way of examples. The hot steel plate sent out from the hot finishing mill was straightened and cooled using a device within the scope of the present invention (Example), and straightened and cooled using a device outside the present invention. The case (comparative example) will be described.

Tables 3 to 19 and Tables 20 and 21 show the main equipment contents of the equipment for straightening and cooling the high-temperature steel sheet and the main use conditions of the equipment in the tests of Examples 1 to 17 and Comparative Examples 1 and 2, respectively. Show.

The following items were common to all of the examples and comparative examples. Common test conditions: Conveying, cooling, and draining of steel sheet in cooling system Method: Conveying by constraining rolls, cooling with cooling water during passing between rolls, draining with constraining rolls Number of sets of constraining rolls: 20 Sets of constraining rolls: 1000mm Upper and lower roll gap setting value: Steel plate thickness-1.5mm Second straightening device (referred to as "outside straightening device") Method and structure: quadruple hot leveler Leveling roll: Flat roll (Note 1) Cooling The zones were either cooled in all sections between the rolls or in every other section.

(Note 2) A plurality of nozzles and one slit nozzle installed in parallel with the width direction of the plate are each referred to as a nozzle row. (In this specification, the term “nozzle row” is used in this sense.) (Note 3) The first straightening device is referred to as “entrance-side straightening device”.

(Note 4) The inlet-side correction device, guide, fluid ejection mechanism (spray nozzle for removing water leakage), and cooling nozzle adjustment mechanism were always provided, but tests were conducted with and without this.

Hereinafter, each test of the examples and comparative examples will be described.
1 to 19 and Tables 3 to 21.
You. (Example 1) Table 3 shows the test conditions. Hot finishing mill
12mm thick, 3.2m wide, 30m long
While conveying the high temperature steel plate at a speed of 120 m / min,
Straightening with the device of Embodiment 1 (see FIG. 1), cooling,
Was corrected. The double-sided simple hot
Feed into the Traveler and form a steel plate with 5 flat rolls
The condition was corrected. Then, in the cooling device, the upper cooling nozzle
One row of slit nozzles immediately after the exit side of each restraining roll
And the cooling water flow density at the top of the steel plate is 4.0m ^Three/ Mi
nm^TwoAnd flow along the plate toward the downstream side in the plate travel direction
Was. On the other hand, the lower cooling nozzle is
With the pipe jet nozzle with the conduit submerged in the water facing upward (Fig. 7
), 1 nozzle row with 100 mm nozzle hole pitch
Five rows are arranged at 67mm intervals, and water is injected from a circular pipe.
1. The cooling water flow density on the lower surface of the steel plate
3m^Three/ Min · m^TwoAnd cooled. However, in the first embodiment
Performed the above water cooling in every other cooling zone. cold
During cooling, a spray nozzle to remove water leakage from the
The adjusting mechanism of the cooling nozzle was not operated. In addition,
The spray nozzle to remove the cooling water leak to the outlet side of the
I didn't.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the maximum temperature and the minimum temperature in the plate width direction and the longitudinal direction was 4 ° C., and the temperature was 12 ° C., and substantially uniform cooling was performed over the entire surface. Then, the steepness α of the ear wave shape according to the above equation (1) is 0.
It was as small as 02%.

Example 2 Table 4 shows the test conditions. 25mm thickness and 4.0 width sent from hot finishing mill
A high-temperature steel plate having a length of 15 m and a length of 15 m was straightened by the apparatus of Embodiment 1 (see FIG. 1) while being conveyed at a speed of 120 m / min, cooled, and then straightened. Without using the entrance guide, 2
It was sent to a heavy duty simple hot leveler, and the shape was corrected with five crowning leveling rolls. The crown shape adopted a sine curve, and the roll body length was set so as to correspond to a half wavelength of the sine function. Next, in the cooling device, as an upper cooling nozzle, a row of slit nozzles is arranged one row immediately after the exit side of each constraining roll, and the cooling water flow density on the upper surface of the steel plate is 4.0.
It flowed along the plate at m ³ / min · m ² toward the downstream side in the plate traveling direction. On the other hand, the lower cooling nozzles are arranged such that a circular pipe jet nozzle with a conduit submerged in water is directed upward between the constraining rolls (see FIG. 7), and the nozzle rows having a nozzle hole pitch of 100 mm in the rows are arranged in five rows at intervals of 167 mm. Then, water was injected from a circular pipe and cooled by a cooling water flow density of 2.3 m ³ / min · m ² on the lower surface of the steel sheet with a water flow generated by the accompanying flow. However,
In Example 2, the water cooling was performed every other cooling zone. During cooling, the spray nozzle for removing water leakage from the constraining roll and the adjusting mechanism of the cooling nozzle were not operated.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the maximum temperature and the minimum temperature in the plate width direction and the longitudinal direction was 2 ° C., and the entire surface was uniformly cooled. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 5%.

(Example 3) Table 5 shows the test conditions. Thickness 15mm, width 3.2 sent from hot finishing mill
While conveying at a speed of 100 m / min, a high-temperature steel sheet having a length of 20 m and a length of 20 m was straightened by the apparatus of Embodiment 2 (see FIG. 10), cooled, and then straightened. The centering of the steel sheet width was performed using the entrance roller guide, and it was sent to a double type simple hot leveler, and the shape was corrected with five flat leveling rolls. Next, in the cooling device, a slit nozzle is provided as an upper cooling nozzle immediately after the exit side of each restraining roll.
The cooling water flow density on the upper surface of the steel plate is 4.0 m ³ / m.
It flowed along the plate at in · m ² toward the downstream side in the plate traveling direction. On the other hand, the lower cooling nozzles are arranged such that the circular tube laminar nozzles face upward between the constraining rolls (see FIG. 6), and the nozzle rows having a nozzle hole pitch of 70 mm in the rows are arranged at intervals of 111 mm.
^They were arranged in a row, and water was injected from a circular pipe to cool the steel sheet at a cooling water flow density of 5.3 m ³ / min · m ² on the lower surface. However, in Example 3, the water cooling was performed every other cooling zone. In addition, the adjustment mechanism of the spray nozzle for water leakage removal and the cooling nozzle was not operated.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
At 0 ° C., the difference between the maximum temperature and the minimum temperature in the plate width direction and the longitudinal direction was 5 ° C., and almost uniform cooling was performed. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 9%.

(Example 4) Table 6 shows the test conditions. Thickness 20 mm, width 4.5 sent from hot finishing mill
The high-temperature steel sheet having a length of 15 m and a length of 15 m was straightened by the apparatus shown in Embodiment 2 (see FIG. 10) while being conveyed at a speed of 75 m / min, cooled, and then straightened. It was fed into a double simple hot leveler using the entry roller guide mechanism. The shape was corrected with five leveling rolls with crown. The crown shape is a sin curve and the roll body length is s
It was applied so as to be half the wavelength of the in function. Next, in the cooling device, slit nozzles are arranged one row at a time immediately after the exit side of each constraining roll as an upper cooling nozzle, and the cooling water flow density on the upper surface of the steel sheet is 5.3 m ³ / min · m ² toward the downstream side in the sheet traveling direction. , Flowed along the plate. On the other hand, a circular laminar nozzle was used as the lower cooling nozzle (see FIG. 6). Eight nozzle rows with a nozzle hole pitch of 70 mm in the row were arranged at an interval of 111 mm, water was injected from a circular pipe, and the steel sheet was cooled at a cooling water flow density of 5.3 m ³ / min · m ² on the lower surface. However, in Example 4, the water cooling was performed every other cooling zone. In addition, the adjustment mechanism of the spray nozzle for water leakage removal and the cooling nozzle was not operated.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the maximum temperature and the minimum temperature in the plate width direction and the longitudinal direction was 3 ° C., and the cooling was substantially uniform over the entire surface. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 4%.

(Example 5) Table 7 shows the test conditions. Hot
12mm thickness and 4.5 width sent from finishing mill
m, high-temperature steel plate with a length of 30m at a speed of 120m / min
While transporting, the apparatus shown in Embodiment 3 (FIGS. 12 and 1)
3), cooled and then straightened. Entrance guy
Without using the mechanism, feed into a double simple hot leveler
It is. The steel plate shape was corrected with five flat rolls. Next
In the cooling device, each constrained roll is used as an upper cooling nozzle.
The slit nozzles are arranged one row at a time immediately after the
Surface cooling water flow density 4.0m^Three/ Min · m^TwoHow to proceed with the board
It flowed along the plate toward the downstream side. On the other hand,
The chisel is provided with a slit nozzle 10 arranged in parallel to the plate width direction.
(See FIG. 4). The spacing between rows is 167 mm, and
The lit nozzle 10 is arranged, and a steel plate is
Flow along the lower surface, cooling water flow density of the lower surface 6.3m ^Three/ M
in ・ m^TwoAnd cooled. However, in Example 5, the water cooling
Cooling was performed every other cooling zone. Furthermore, water leakage removal
Each water is sprayed from the water spray nozzle.
Cooling water leaking from the constraining rolls immediately from the plate side end
Removed. Do not operate the cooling nozzle adjustment mechanism.
Was.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
At 6 ° C., no difference was observed between the maximum temperature and the minimum temperature in the plate width direction and the longitudinal direction, and uniform cooling was performed over the entire surface. And
The steepness α of the ear wave shape according to the above equation (1) is 0.04%
Was small.

(Example 6) Table 8 shows the test conditions. Thickness 20 mm, width 3.2 sent from hot finishing mill
A high-temperature steel sheet having a length of 15 m and a length of 15 m was straightened, cooled, and then straightened using the apparatus of the apparatus shown in Embodiment 3 (FIG. 12) while being conveyed at a speed of 75 m / min. Without using the entrance-side guide mechanism, it was fed into a double-type simple hot leveler, which is an entrance-side correction device. Here, the shape of the steel plate was corrected using five rolls with a crown. The crown shape adopted a sine curve, and the roll body length was set so as to correspond to a half wavelength of the sine function. Next, in the cooling device, a slit nozzle is arranged one row at a time immediately after the exit side of each constraining roll as an upper cooling nozzle, and the cooling water flow density on the upper surface of the steel plate is 4.0 m ³ / min.
In · m ² towards the plate advancing direction downstream side, was passed along a plate.
On the other hand, as the lower cooling nozzle, a slit nozzle 10 was arranged parallel to the plate width direction (see FIG. 4). 167 spacing between rows
mm, five rows of slit nozzles 10 were arranged, flowed along the lower surface of the steel sheet in the traveling direction of the plate, and cooled at a cooling water flow density of 6.3 m ³ / min · m ² on the lower surface. However, in Example 6, the water cooling was performed every other cooling zone. Further, the cooling water leaked from each constraining roll was quickly removed from the plate side end by the water injected from the water injection spray nozzle for water removal. The cooling nozzle adjustment mechanism was not operated.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the maximum temperature and the minimum temperature in the plate width direction and the longitudinal direction was 1 ° C., and the entire surface was uniformly cooled. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 9%.

Example 7 Table 9 shows the test conditions. Thickness 15mm, width 4.0 sent from hot finishing mill
The apparatus shown in Embodiment 4 while conveying a high-temperature steel plate having a length of 15 m and a length of 15 m at a speed of 100 m / min (see FIG. 14).
Was used to straighten, cool, and straighten. Using a flat guide as the entry side guide mechanism, centering the width of the steel plate, sending it to the double simple hot leveler,
The shape was corrected with five flat leveling rolls. Next, in the cooling device, as an upper cooling nozzle, a row of slit nozzles is disposed one row at a time immediately after the exit side of each constraining roll, and the cooling water flow density on the upper surface of the steel sheet is 4.0 m ³ / min · m ² toward the downstream side in the plate advancing direction. , Flowed along the plate. On the other hand, the lower cooling nozzle is arranged such that the pipe jet nozzle with a conduit submerged in water is directed upward between the constraining rolls (see FIG. 7), and a nozzle row having an in-row nozzle hole pitch of 100 mm is formed at intervals of 167 mm.
The cooling water flow density on the lower surface of the steel plate is 2.3m ³ / min · m
Cooled in ² . However, in Example 7, the water cooling was performed every other cooling zone. Then, the cooling water leaked from each of the constraining rolls was quickly removed from the plate side end by the water sprayed from the water leakage spray nozzle. The cooling nozzle adjustment mechanism was not operated.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the highest temperature and the lowest temperature in the plate width direction and the longitudinal direction was 2 ° C., and substantially uniform cooling was performed over the entire surface. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 3%.

(Example 8) Table 10 shows the test conditions. Thickness 12mm, width 4.0 sent from hot finishing mill
The apparatus shown in Embodiment 4 while conveying a high-temperature steel plate having a length of 30 m and a length of 30 m at a speed of 120 m / min (see FIG. 14).
Was used to straighten, cool, and straighten. Using a flat guide as the entry side guide mechanism, centering the width of the steel plate, sending it to the double simple hot leveler,
The shape was corrected with five leveling rolls with crown. The crown shape adopted a sine curve, and the roll body length was set so as to correspond to a half wavelength of the sine function. Next, in the cooling device, as an upper cooling nozzle, a row of slit nozzles is disposed one row at a time immediately after the exit side of each constraining roll, and the cooling water flow density on the upper surface of the steel sheet is 4.0 m ³ / min · m ² toward the downstream side in the plate advancing direction. , Flowed along the plate. On the other hand, the lower cooling nozzles are arranged between the constraining rolls such that the circular pipe jet nozzles with conduits submerged in water face upward (see FIG. 7), and five rows of nozzles having a nozzle hole pitch of 100 mm are arranged at intervals of 167 mm. And water is injected from the circular pipe, and the water flow generated by the accompanying flow
The steel sheet was cooled at a cooling water flow density of 2.3 m ³ / min · m ² on the lower surface. Water cooling was performed in all 19 cooling zones. Further, the cooling water leaked from each constraining roll was quickly removed from the plate side end by the water injected from the water injection spray nozzle for water removal. The cooling nozzle adjustment mechanism was not operated.

In the cooling test, the surface temperature distribution of the steel sheet was measured with a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the maximum temperature and the minimum temperature in the sheet width direction and the longitudinal direction was 9 ° C., and the entire surface was uniformly cooled. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 7%.

(Example 9) Table 11 shows the test conditions. Thickness 40 mm, width 4.0 sent from hot finishing mill
The high-temperature steel sheet having a length of 15 m and a length of 15 m was straightened, cooled, and then straightened using the apparatus shown in Embodiment 5 (see FIG. 15) while being conveyed at a speed of 53 m / min. Without using the entry side guide, send it to the double simple hot leveler,
The shape was corrected with a flat leveling roll of books. Next, in the cooling device, as an upper cooling nozzle, a row of slit nozzles is disposed one row at a time immediately after the exit side of each constraining roll, and the cooling water flow density on the upper surface of the steel sheet is 4.0 m ³ / min · m ² toward the downstream side in the plate advancing direction. , Flowed along the plate. On the other hand, the lower cooling nozzles are arranged between the constraining rolls such that the circular pipe jet nozzles with conduits submerged in water face upward (see FIG. 7), and five rows of nozzles having a nozzle hole pitch of 100 mm are arranged at intervals of 167 mm. Then, water is injected from a circular pipe, and a water flow generated by the accompanying flow of the water flows, and a cooling water flow density of 2.3 m ³ / min · m ² on the lower surface of the steel plate.
And cooled. In this test, the cooling nozzle adjustment mechanism 22 (see FIG. 16; however, illustration is omitted for the second and subsequent cooling zones) is performed so that the cooling water injected from the upper and lower cooling nozzles comes into contact with the steel plate. The starting position in the plate longitudinal direction was adjusted so that the upper surface and the lower surface of the steel plate coincided with each other. The configuration of the cooling nozzle adjusting mechanism 22 includes, for example, a fine adjustment driving mechanism 25, an arm 26 connected thereto, and a connecting rod 27 connecting the same row of the lower cooling nozzles 8 collectively. By the movement of the connecting rod 27, the lower cooling nozzles 8 belonging to the same row are finely moved back and forth. The above water cooling was performed in all cooling zones of the 19 sections. In addition,
Cooling leakage from each restraining roll was not removed by the removal spray.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the maximum temperature and the minimum temperature in the sheet width direction and the longitudinal direction was 7 ° C., and substantially uniform cooling was performed over the entire surface. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 5%.

(Example 10) Table 12 shows the test conditions.
2. A thickness of 15 mm and a width of 3 delivered from a hot finishing mill.
6m, 20m long high temperature steel plate, 100m / min speed
Using the apparatus described in the fifth embodiment (see FIG. 15), straightening, cooling, and straightening were performed. The sheet was fed into a double simple hot leveler without using the entrance side guide, and the shape was corrected with five flat leveling rolls. Then, in the cooling device, slit nozzles are arranged one row at a time immediately after the exit side of each constraining roll as an upper cooling nozzle, and the cooling water flow density on the upper surface of the steel plate is 4.0 m ³ / min · m ^2.
And flowed along the plate toward the downstream side in the plate traveling direction. on the other hand,
As the lower cooling nozzle, a perforated plate nozzle was used (FIGS. 8, 9).
reference). The nozzle hole pitch in the row of the perforated plate is 100 mm,
Nineteen nozzle rows were arranged at intervals of 50 mm, and the nozzle holes were arranged in a staggered manner. Here, the reason why the row interval between the perforated plate nozzles is set to 50 mm is that if the water flow rate is 50 mm or less, uniform cooling with almost no unevenness in the width direction is performed under the condition of the amount of water. The cooling water flow density on the lower surface of the steel sheet is 6.3.
m ³ / min · m ² . In this test, by operating the cooling nozzle adjusting mechanism 22 (see FIG. 16), the position in the plate longitudinal direction at which the cooling water injected from the upper and lower cooling nozzles starts to contact the steel plate is shifted between the upper surface and the lower surface of the steel plate. Was adjusted to match. However, the water cooling was performed every other cooling zone. Further, the cooling water leak from each of the constraining rolls was not removed by the removing spray.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of the cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the maximum temperature and the minimum temperature in the plate width direction and the longitudinal direction was 7 ° C., and substantially uniform cooling was performed over the entire surface. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 4%.

(Example 11) Table 13 shows the test conditions.
2. thickness 25 mm, width 3 sent out from the hot finishing mill.
High-speed steel plate of 2m, length 15m, speed 100m / min
Using the apparatus described in the fifth embodiment (see FIG. 15), straightening, cooling, and straightening were performed. The sheet was fed into a double-type simple hot leveler without using the entrance side guide, and the shape was corrected by five leveling rolls with a crown. The crown shape adopted a sine curve, and the roll body length was set so as to correspond to a half wavelength of the sine function. Then
In the cooling device, as an upper cooling nozzle, a row of slit nozzles is arranged one row at a time immediately after the exit side of each of the constraining rolls, and the cooling water flow density on the upper surface of the steel sheet is 4.0 m ³ / min · m ² , toward the downstream side in the sheet traveling direction. Shed along. On the other hand, a perforated plate nozzle was used as the lower cooling nozzle (see FIGS. 8 and 9). The perforated plate nozzles used were the same as those in Example 10, the nozzle hole pitch in the row was 100 mm, and the nozzle row was 1 mm at intervals of 50 mm.
Nine rows were arranged, and the nozzle holes were arranged in a staggered manner. Also,
The cooling water flow density on the lower surface of the steel sheet was 6.3 m ³ / min · m ² . In this test, by operating the cooling nozzle adjusting mechanism 22 (see FIG. 16), the position in the plate longitudinal direction at which the cooling water injected from the upper and lower cooling nozzles starts to contact the steel plate is shifted between the upper surface and the lower surface of the steel plate. Was adjusted to match. The water cooling was performed in all 19 cooling zones. In addition, the cooling water leak from each restraining roll was not removed by the removal spray.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the maximum temperature and the minimum temperature in the width direction and the longitudinal direction was 1 ° C., and the difference between the maximum temperature and the minimum temperature was 5 ° C., so that substantially uniform cooling was performed over the entire surface. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 9%. Table 14 shows the new (Example 12) test conditions. The high-temperature steel plate having a thickness of 12 mm, a width of 3.6 m, and a length of 30 m sent from the hot finishing mill is transported at a speed of 120 m / min using the apparatus shown in Embodiment 6 (see FIG. 17). Straightened, cooled and then straightened. A plate guide was used as an entrance side guide, and the plate was fed into a double-type simple hot leveler, and the shape was corrected with five flat leveling rolls. Then, in the cooling device, slit nozzles are arranged one row at a time immediately after the exit side of each constraining roll as an upper cooling nozzle, and the cooling water flow density on the upper surface of the steel plate is 4.0 m ³ / min · m ^2.
And flowed along the plate toward the downstream side in the plate traveling direction. on the other hand,
The lower cooling nozzles are arranged such that the spray nozzles 11 face upward (see FIG. 5), eight rows of nozzles having a nozzle hole pitch of 200 mm in the rows are arranged at intervals of 111 mm, and a cooling water flow density of 1.8 m ³ / min. It was cooled in m ^2. Here, the cooling nozzle adjusting mechanism 22 (see FIG. 16) is operated to adjust the jetting direction of the nozzle holes of the lower first row spray nozzles 11 so that the position at which the cooling water starts to contact the lower surface of the steel plate is determined. As a result, the cooling water was brought into contact with the upper and lower surfaces of the steel plate at the same position in the longitudinal direction of the steel plate. However, the water cooling was performed every other cooling zone. Further, the cooling water leak from each of the constraining rolls was not removed by the removing spray.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the maximum temperature and the minimum temperature in the sheet width direction and the longitudinal direction was 7 ° C., and substantially uniform cooling was performed on the entire surface. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 2%.

(Example 13) Table 15 shows the test conditions.
2. Thickness 20 mm, width 3 sent from hot finishing mill.
The apparatus shown in Embodiment 6 (see FIG. 17) while conveying a 6 m high-temperature steel plate having a length of 15 m at a speed of 75 m / min.
Was used to straighten, cool, and straighten. A plate guide was used as an entrance guide, and the plate was fed into a double-type simple hot leveler, and the shape was corrected by five leveling rolls with a crown. Crown shape adopts sin curve,
The roll body length was set so as to be a half wavelength of the sin function. Then, in the cooling device, slit nozzles are arranged one row at a time immediately after the exit side of each constraining roll as an upper cooling nozzle, and the cooling water flow density on the upper surface of the steel plate is 4.0 m ³ / min · m ^2.
And flowed along the plate toward the downstream side in the plate traveling direction. on the other hand,
The lower cooling nozzles are arranged such that the spray nozzles 11 face upward (see FIG. 5), eight rows of nozzles having a nozzle hole pitch of 200 mm in the rows are arranged at intervals of 111 mm, and a cooling water flow density of 1.8 m ³ / min. It was cooled in m ^2. Here, the cooling nozzle adjusting mechanism 22 (see FIG. 16) is operated to adjust the jetting direction of the nozzle holes of the lower first row spray nozzles 11 so that the position at which the cooling water starts to contact the lower surface of the steel plate is determined. As a result, the cooling water was brought into contact with the upper and lower surfaces of the steel plate at the same position in the longitudinal direction of the steel plate. However, the water cooling was performed every other cooling zone. Further, the cooling water leak from each of the constraining rolls was not removed by the removing spray.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the maximum temperature and the minimum temperature in the plate width direction and the longitudinal direction was 4 ° C., and the entire surface was uniformly cooled. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 8%.

(Example 14) Table 16 shows the test conditions.
3. A thickness of 15 mm and a width of 4 delivered from a hot finishing mill.
5m high-temperature steel plate of 15m length, 100m / min speed
Using the apparatus described in the seventh embodiment (see FIG. 18), straightening, cooling, and straightening were performed. The sheet was fed into a double-type simple hot leveler without using the entrance side guide, and the shape was corrected with five flat leveling rolls. Then, in the cooling device, slit nozzles are arranged one row at a time immediately after the exit side of each constraining roll as an upper cooling nozzle, and the cooling water flow density on the upper surface of the steel plate is 4.0 m ³ / min · m ^2.
And flowed along the plate toward the downstream side in the plate traveling direction. on the other hand,
The lower cooling nozzles are arranged between the constraining rolls such that the circular pipe jet nozzle submerged in water is turned upward (see FIG. 7), and five nozzle rows having a nozzle hole pitch of 100 mm in the rows are arranged at intervals of 167 mm. Injecting water from a circular pipe, the water flow generated by the accompanying flow, the cooling water flow density of 2.3 m ³
/ Min · m ² . Cooling nozzle adjustment mechanism 22
(Refer to FIG. 16), the spray direction of the nozzle holes of the lower first row spray nozzles 11 is adjusted, and the position where the cooling water starts to contact the lower surface of the steel plate is adjusted. The position at which the cooling water starts contacting the lower surface in the longitudinal direction of the steel plate was set to be the same. However, the water cooling was performed every other cooling zone. Further, the cooling water leaked from each constraining roll was quickly removed from the plate side end by the water injected from the water injection spray nozzle for water removal.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the maximum temperature and the minimum temperature in the sheet width direction and the longitudinal direction was 7 ° C., and substantially uniform cooling was performed over the entire surface. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 1%.

(Example 15) Table 17 shows the test conditions.
3. thickness 12 mm, width 4 sent from hot finishing mill.
5m, high-temperature steel plate of 20m length, speed 120m / min
Using the apparatus described in the seventh embodiment (see FIG. 18), straightening, cooling, and straightening were performed. The paper was fed into a double-type simple hot leveler without using an entrance guide, and the shape was corrected by five leveling rolls with a crown. The crown shape adopted a sine curve, and the roll body length was set so as to correspond to a half wavelength of the sine function. Then
In the cooling device, as an upper cooling nozzle, a row of slit nozzles is arranged one row at a time immediately after the exit side of each of the constraining rolls, and the cooling water flow density on the upper surface of the steel sheet is 4.0 m ³ / min · m ² , toward the downstream side in the sheet traveling direction. Shed along. On the other hand, the lower cooling nozzles are arranged such that a circular pipe jet nozzle with a conduit submerged in water is directed upward between the constraining rolls (see FIG. 7), and five rows of nozzles having a nozzle pitch of 100 mm in the rows are arranged at intervals of 167 mm. The cooling water flow density on the lower surface of the steel plate is 2.3 m ³ / min · m ² by the water flow generated by the water flow injected from the circular pipe and the accompanying flow.
And cooled. Cooling nozzle adjustment mechanism 22 (see FIG. 16)
Is operated to adjust the injection direction of the nozzle holes of the lower first row spray nozzles 11 to adjust the position where the cooling water starts to contact the lower surface of the steel plate. As a result, the cooling water flows on the upper and lower surfaces of the steel plate. The position in the longitudinal direction of the steel plate at which the contact was started was the same. However, the water cooling was performed every other cooling zone. Further, the cooling water leaked from each constraining roll was quickly removed from the plate side end by the water injected from the water injection spray nozzle for water removal.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the highest temperature and the lowest temperature in the sheet width direction and the longitudinal direction was 1 ° C., and 6 ° C., so that substantially uniform cooling was performed over the entire surface. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 4%.

(Example 16) Table 18 shows the test conditions.
2. thickness 12 mm, width 3 sent out from the hot finishing mill.
High speed steel plate of 2m, length 30m, speed 120m / min
Using the apparatus described in Embodiment 8 (see FIG. 19), the sheet was straightened, cooled, and straightened. Using a plate guide as the entry side guide, centering the width of the steel plate and sending it to the double simple hot leveler,
The shape was corrected with five flat leveling rolls. Next, in the cooling device, as an upper cooling nozzle, a row of slit nozzles is disposed one row at a time immediately after the exit side of each constraining roll, and the cooling water flow density on the upper surface of the steel sheet is 4.0 m ³ / min · m ² toward the downstream side in the plate advancing direction. , Flowed along the plate. On the other hand, as the lower cooling nozzle, a slit nozzle 10 was arranged parallel to the plate width direction (see FIG. 4). The spacing between the rows is 167 mm, and five rows of slit nozzles 10 are arranged and flow along the lower surface of the steel sheet in the direction of travel of the plate, and the cooling water flow density on the lower surface is 6.3 m ³ /
Cooled at min.m ² . However, the water cooling was performed every other cooling zone. Cooling nozzle adjustment mechanism 22
(See FIG. 16) to adjust the injection position of the lower first-row slit nozzle 10 to adjust the position at which the cooling water starts to contact the lower surface of the steel plate, and as a result, to cool the upper and lower surfaces of the steel plate. The position in the longitudinal direction of the steel sheet at which water starts contacting was set to be the same. However, the water cooling was performed every other cooling zone. Further, the cooling water leaked from each constraining roll was quickly removed from the plate side end by the water injected from the water injection spray nozzle for water removal.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the maximum temperature and the minimum temperature in the plate width direction and the longitudinal direction was 1 ° C., and the entire surface was uniformly cooled. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 4%.

(Example 17) Table 19 shows the test conditions.
2. thickness 25 mm, width 3 sent out from the hot finishing mill.
6m, length 15m high temperature steel plate, 100m / min speed
Using the apparatus described in Embodiment 8 (see FIG. 19), the sheet was straightened, cooled, and straightened. Using a plate guide as the entry side guide, centering the width of the steel plate and sending it to the double simple hot leveler,
The shape was corrected with five leveling rolls with crown. The crown shape adopted a sine curve, and the roll body length was set so as to correspond to a half wavelength of the sine function. Next, in the cooling device, as an upper cooling nozzle, a row of slit nozzles is disposed one row at a time immediately after the exit side of each constraining roll, and the cooling water flow density on the upper surface of the steel sheet is 4.0 m ³ / min · m ² toward the downstream side in the plate advancing direction. , Flowed along the plate. On the other hand, as the lower cooling nozzle, a slit nozzle 10 was arranged parallel to the plate width direction (see FIG. 4). The interval between the rows is 167 mm, and five rows of slit nozzles 10 are arranged. The slit nozzles 10 flow along the lower surface of the steel sheet in the traveling direction of the plate, and the cooling water flow density on the lower surface is 6.3 m ³ / mi.
was cooled in n · m ^2. Cooling nozzle adjustment mechanism 22 (FIG. 1)
6) to operate the lower first slit nozzle 1
The injection position of 0 is adjusted to adjust the position at which the cooling water starts to contact the lower surface of the steel plate. As a result, the position in the longitudinal direction of the steel plate at which the cooling water starts to contact the upper and lower surfaces of the steel plate is the same. did. The water cooling was performed in all 19 cooling zones.
Further, the cooling water leaked from each constraining roll was quickly removed from the plate side end by the water injected from the water injection spray nozzle for water removal.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the highest temperature and the lowest temperature in the plate width direction and the longitudinal direction was 4 ° C., and the entire surface was uniformly cooled. The steepness α of the ear wave shape according to the above equation (1) is 0.0
It was as small as 6%.

(Comparative Example 1) Table 20 shows the test conditions. Thickness 20 mm, width 3.6 sent from hot finishing mill
A high-temperature steel sheet having a length of 15 m and a length of 15 m was cooled by a cooling device without correcting the shape of the steel sheet while being conveyed at a speed of 75 m / min, and then corrected. The cooling device has a space of 10
Twenty sets of constraining rolls are provided at a distance of 00 mm, and a slit nozzle is arranged as an upper cooling nozzle immediately after the exit side of each constraining roll, one row at a time, and the cooling water flow density on the upper surface of the steel plate is 4.0 m.
It flowed along the plate at ³ / min · m ² toward the downstream side in the plate traveling direction. On the other hand, the lower cooling nozzles are arranged between the constraining rolls such that the circular pipe jet nozzles with conduits submerged in water face upward (see FIG. 7), and five rows of nozzles having a nozzle hole pitch of 100 mm are arranged at intervals of 167 mm. Then, water was injected from the circular pipe, and the water flow generated by the accompanying flow was used to cool the steel sheet under the cooling water flow density of 2.3 m ³ / min · m ² . The water cooling was performed in all 19 cooling zones. Then, the cooling water leaked from each of the constraining rolls was quickly removed from the plate side end by the water sprayed from the water leakage spray nozzle. The cooling nozzle adjustment mechanism was not operated.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 51
The difference between the maximum temperature and the minimum temperature in the sheet width direction and the longitudinal direction was 0 ° C., and the difference between the maximum temperature and the minimum temperature was 108 ° C., and large cooling unevenness occurred in the steel sheet.
The steepness α of the ear wave shape according to the above equation (1) is
It was as large as 1.08%.

(Comparative Example 2) Table 21 shows the test conditions. 15mm thickness and 4.5 width sent out from hot finishing mill
A high-temperature steel sheet having a length of 15 m and a length of 15 m was cooled by a cooling device without correcting the shape of the steel sheet while being conveyed at a speed of 75 m / min, and then corrected. The cooling device has a space of 10
Twenty sets of constraining rolls are provided at a distance of 00 mm, and a slit nozzle is arranged as an upper cooling nozzle immediately after the exit side of each constraining roll, one row at a time, and the cooling water flow density on the upper surface of the steel plate is 4.0 m.
It flowed along the plate at ³ / min · m ² toward the downstream side in the plate traveling direction. On the other hand, the lower cooling nozzles are arranged between the constraining rolls such that the circular pipe jet nozzles with conduits submerged in water face upward (see FIG. 7), and five rows of nozzles having a nozzle hole pitch of 100 mm are arranged at intervals of 167 mm. Then, water was injected from the circular pipe, and the water flow generated by the accompanying flow was used to cool the steel sheet under the cooling water flow density of 2.3 m ³ / min · m ² . The cooling nozzle adjustment mechanism 22 (see FIG. 16) is operated, and the lower first
The injection position of the row slit nozzle 10 is adjusted to adjust the position at which the cooling water starts to contact the lower surface of the steel sheet. As a result,
The position in the longitudinal direction of the steel plate where the cooling water starts to contact the upper and lower surfaces of the steel plate was made the same. The water cooling was performed in all 19 cooling zones. Further, the cooling water leaked from each constraining roll was quickly removed from the plate side end by the water injected from the water injection spray nozzle for water removal.

In the cooling test, the surface temperature distribution of the steel sheet was measured by a scanning radiation thermometer 20 seconds after the completion of cooling. As a result, the average temperature of the steel sheet surface was 50
The difference between the highest temperature and the lowest temperature in the sheet width direction and the longitudinal direction was 80 ° C., and large cooling unevenness occurred in the steel sheet. The steepness α of the ear wave shape according to the above equation (1) is 1.
It was as large as 68%.

In the above examples and comparative examples, the flow rate of the cooling water from the upper and lower cooling nozzles of the cooling device was adjusted.
The row spacing of the lower cooling nozzles and the nozzle hole pitch in the plate width direction were determined as follows.

In order to balance the cooling capacity of the cooling water between the upper surface and the lower surface of the steel sheet, specifically, the amount of heat removed by the steel sheet in each cooling zone when the steel sheet passes through each cooling zone. Adjust the amount of cooling water on the upper and lower surfaces so that the amount of heat is the same on the upper and lower surfaces.

The amount of cooling water from each row (indicating a nozzle row parallel to the plate width direction) on the lower side of the steel sheet is adjusted so that the temperature histories of the upper and lower surfaces of the steel sheet during cooling are the same. by the way,
Since the cooling water on the lower surface side immediately drops due to gravity after colliding with the steel plate, the number of nozzle rows is increased and the interval is reduced to some extent. Then, in order to make the local heat flux distribution symmetrical on the upper and lower surfaces, the cooling water flow rate from the lower cooling nozzle having a plurality of nozzle rows is changed by changing the nozzle row for each nozzle row.

The number of rows of the lower cooling nozzles and the nozzle holes in the plate width direction are determined to be equal to or less than a certain upper limit so as not to cause cooling unevenness. The upper limit of the number of rows and the pitch varies depending on the type of nozzle and the amount of injected water.

The cooling becomes more uniform as the nozzle row interval and the nozzle hole pitch in the row become denser, but should be kept within appropriate ranges in consideration of the maintainability and economy of the apparatus. .

[0166]

[Table 3]

[0167]

[Table 4]

[0168]

[Table 5]

[0169]

[Table 6]

[0170]

[Table 7]

[0171]

[Table 8]

[0172]

[Table 9]

[0173]

[Table 10]

[0174]

[Table 11]

[0175]

[Table 12]

[0176]

[Table 13]

[0177]

[Table 14]

[0178]

[Table 15]

[0179]

[Table 16]

[0180]

[Table 17]

[0181]

[Table 18]

[0182]

[Table 19]

[0183]

[Table 20]

[0184]

[Table 21]

[0185]

As described above, according to the present invention,
When cooling the hot-rolled high-temperature steel sheet, it is possible to uniformly cool the upper and lower surfaces of the steel sheet, so that distortion due to heat after cooling is prevented, and there is no defective shape of the steel sheet. And subsequent refining costs are reduced. Furthermore,
Troubles due to defective shape of the steel sheet while passing through the cooling device are reduced, and the operation rate of the equipment is improved, and the variation in the material of the steel sheet due to insufficient cooling and overcooling is reduced, so that a uniform product can be obtained. Many industrially useful effects such as an improvement in product yield are brought about.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view illustrating a first embodiment of the device of the present invention.

FIG. 2 is a perspective view showing a main part of the first straightening device in FIG.

FIG. 3 is a partial perspective view of a main part of the cooling device in FIG.

FIG. 4 is a schematic longitudinal sectional view illustrating a case where the lower cooling nozzle is a slit nozzle in the first embodiment of the apparatus of the present invention.

FIG. 5 is a schematic longitudinal sectional view illustrating a case where the lower cooling nozzle is a spray nozzle in the first embodiment of the device of the present invention.

FIG. 6 is a schematic longitudinal sectional view illustrating a case where the lower cooling nozzle is a circular laminar nozzle in the first embodiment of the device of the present invention.

FIG. 7 is a schematic longitudinal sectional view illustrating a case where the lower cooling nozzle is a circular pipe nozzle with a conduit in the first embodiment of the apparatus of the present invention.

FIG. 8 is a schematic longitudinal sectional view illustrating a case where the lower cooling nozzle is a perforated plate nozzle in the first embodiment of the apparatus of the present invention.

FIG. 9 is a plan view of the multi-plate nozzle of FIG. 6;

FIG. 10 is a schematic explanatory view showing a second embodiment of the device of the present invention.

11 is a perspective view showing an example of a main part of a guide, a cooling device and the like in FIG. 10;

FIG. 12 is a schematic longitudinal sectional view illustrating a third embodiment of the device of the present invention.

FIG. 13 is a perspective view showing an example of a main part of a cooling device provided with the water fountain spray nozzle of FIG.

FIG. 14 is a schematic longitudinal sectional view illustrating a fourth embodiment of the device of the present invention.

FIG. 15 is a schematic longitudinal sectional view illustrating a fifth embodiment of the device of the present invention.

FIG. 16 is a perspective view showing an example of a main part of a cooling device provided with the cooling nozzle adjustment mechanism of FIG.

FIG. 17 is a schematic longitudinal sectional view illustrating a sixth embodiment of the device of the present invention.

FIG. 18 is a schematic longitudinal sectional view illustrating a seventh embodiment of the device of the present invention.

FIG. 19 is a schematic longitudinal sectional view for explaining an eighth embodiment of the device of the present invention.

FIG. 20 is a graph showing the relationship between the steepness of the ear wave shape and the drainability by a drain roll in the cooling device, and the effect of the plate thickness on this relationship.

FIG. 21 is a diagram showing temperature histories of the upper and lower surfaces of a steel plate when the upper and lower surfaces of a high-temperature steel plate are cooled by one slit nozzle.

FIG. 22 is a diagram showing a change over time in the amount of C warpage of a steel sheet when a high-temperature steel sheet is cooled under the same cooling conditions as in FIG. 21.

FIG. 23 is a diagram illustrating a state in which the position of the plate in the plate conveyance direction at which the cooling water starts to contact the upper surface and the lower surface of the steel plate.

24 is a graph showing a relationship between a shift amount of a cooling water contact start position with respect to a steel plate in FIG. 23 and a C warpage amount of the steel plate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Steel plate 2 Hot finishing mill 3 First straightening device 3a Leveling roll 4 Cooling device 5 Second straightening device 6 Restraining roll 6a, 6a 'Upper roll 6b, 6b' Lower roll 7 Upper cooling nozzle 8 Lower cooling nozzle 9 Hydraulic cylinder 10 Slit nozzle 11 Spray nozzle 12 Circular tube laminar nozzle 13 Circular tube jet nozzle with conduit 13a Circular nozzle 13b Conduit 14 Cooling water 15 Vessel 16 Associated flow 17 Perforated plate nozzle 17a Cooling water supply container 17b Ceiling plate 17c Nozzle hole array Reference Signs List 18 Guide mechanism 19 Roll guide 20 Plate guide 21 Water spray spray nozzle 22 Cooling nozzle adjustment mechanism 23 Water absorption nozzle 24 Slit nozzle 25 Fine adjustment drive mechanism 26 Arm 27 Connecting rod p Plate transport direction in which cooling water starts to contact the upper surface of steel plate Position q Cooling water on the underside of the steel plate Deviation L steel traveling direction or plate longitudinal and position of the q of the plate conveyance direction position y p to start contacting

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B21B 45/02 320 B21B 45/02 320V 320S (72) Inventor Akira Tagane 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Japan Inside Steel Pipe Co., Ltd. (72) Inventor Yoshitaka Inoue 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan Inside Steel Pipe Co., Ltd. (72) Inventor Masamasa Kamada 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (72) Inventor Takashi Uchimura 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Masayuki Horie 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Shogo Tomita 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (72) Yoneaki Fujita Inventor Chiyoda-ku, Tokyo Chome No. 1 No. 2 Date. This steel pipe within the Corporation out of (72) inventor Isao Takahashi Marunouchi, Chiyoda-ku, Tokyo chome No. 1 No. 2 Date. This steel pipe in the Corporation

Claims (14)

[Claims] 1. A first straightening device for correcting a shape defect of a hot-rolled hot steel sheet before cooling the steel sheet,
A plurality of sets of constraining rolls are installed on the outlet side of the first straightening device, and one set of rolls are arranged one above and below each other. A cooling device for cooling the steel plate by injecting cooling water into the upper and lower surfaces of the high-temperature steel plate, and installed on an outlet side of the cooling device, and correcting a shape defect of the steel plate cooled by the cooling device. A straightening and cooling device for a high-temperature steel sheet, comprising: a first straightening device having the following configuration (a): (A) The method of the first straightening device is a hot leveler, in which the number of leveling rolls of the hot leveler is 5 or more, and the pressing / driving mechanism of the hot leveler is a double type or more multiple structure. There is. 2. The leveling roll of item (a) has a configuration of item (b) below.
An apparatus for straightening and cooling a high-temperature steel sheet as described above. (B) The leveling roll is crowned. 3. The high-temperature steel sheet according to claim 1, wherein a steel sheet guide mechanism having the following configuration (c) is further added to the entrance of the first straightening device. Straightening and cooling equipment. (C) The guide mechanism of the steel plate has a function of aligning the center line of the high-temperature steel plate with the center line of the straightening device. 4. The invention according to claim 1, 2 or 3, further comprising a fluid ejection mechanism having the following configuration (d) on the outlet side of each of the plurality of sets of constraint rolls of the cooling device. A straightening and cooling device for a high-temperature steel sheet, characterized in that: (D) The fluid ejecting mechanism has a function of forming an ejected fluid from one side end of the upper surface of the steel plate to the other side end. 5. A first straightening device for correcting a shape defect of a hot-rolled hot steel sheet before cooling the steel sheet,
Each of the constraining rolls is installed on the outlet side of the first straightening device, and while the high-temperature steel sheet is conveyed while being bitten by a plurality of constraining rolls forming one set of rolls arranged one by one above and below. A cooling device for cooling the steel plate by injecting cooling water into the upper and lower surfaces of the high-temperature steel plate, and installed on the outlet side of the cooling device, and reducing a shape defect of the steel plate cooled by the cooling device. A high-temperature steel plate straightening and cooling device comprising a second straightening device for straightening, wherein the cooling device is provided with a nozzle having the following configurations (e) and (f). , High temperature steel sheet straightening and cooling equipment. (E) As the nozzle, an upper cooling nozzle and a lower cooling nozzle for injecting cooling water toward each of the upper surface and the lower surface of the steel plate are provided, and in each minute portion of the upper surface in the cooling process of the steel plate. The upper cooling nozzle and the lower cooling nozzle are both so that the temporal change of the temperature and the temporal change of the temperature at each minute portion of the lower surface are the same as the steel plate thickness center plane as a plane of symmetry.
A long nozzle row is formed in the steel sheet width direction, and the number of nozzle rows in which the lower cooling nozzle rows are arranged in the steel sheet length direction is greater than the number of nozzle rows in which the upper cooling nozzles are arranged in the steel sheet length direction. (F) In any cooling zone in which the steel sheet is injected with cooling water between the constraining rolls, the arrangement of the upper cooling nozzle and the lower cooling nozzle is such that the upper cooling nozzle The position in the steel plate length direction at which the cooling water injected from the steel plate starts contacting the upper surface of the steel plate, and the position in the steel plate length direction at which the cooling water injected from the lower cooling nozzle starts contacting the lower surface of the steel plate. That can be adjusted to be identical. 6. The high-temperature apparatus according to claim 1, wherein the cooling device includes a nozzle having the following configurations (e) and (f). Steel plate straightening and cooling equipment. (E) As the nozzle, an upper cooling nozzle and a lower cooling nozzle for injecting cooling water toward each of the upper surface and the lower surface of the steel plate are provided, and in each minute portion of the upper surface in the cooling process of the steel plate. The upper cooling nozzle and the lower cooling nozzle are both so that the temporal change of the temperature and the temporal change of the temperature at each minute portion of the lower surface are the same as the steel plate thickness center plane as a plane of symmetry.
A long nozzle row is formed in the steel sheet width direction, and the number of nozzle rows in which the lower cooling nozzle rows are arranged in the steel sheet length direction is greater than the number of nozzle rows in which the upper cooling nozzles are arranged in the steel sheet length direction. (F) In any cooling zone in which the steel sheet is injected with cooling water between the constraining rolls, the arrangement of the upper cooling nozzle and the lower cooling nozzle is such that the upper cooling nozzle The position in the steel plate length direction at which the cooling water injected from the steel plate starts contacting the upper surface of the steel plate, and the position in the steel plate length direction at which the cooling water injected from the lower cooling nozzle starts contacting the lower surface of the steel plate. That can be adjusted to be identical. 7. The high temperature steel sheet straightening and cooling apparatus according to claim 6, wherein the upper cooling nozzle and the lower cooling nozzle have the following configuration (g). (G) the upper cooling nozzle is constituted by a single row of slit nozzles elongated in the steel sheet width direction, and the lower cooling nozzle is constituted by a plurality of rows of nozzles arranged long in the steel sheet width direction; The type of the nozzle shall be one of a slit nozzle, a spray nozzle, a circular laminar nozzle, a circular jet nozzle with a conduit, or a perforated plate nozzle. 8. On-line in the process of producing a steel sheet by hot rolling, the shape of said steel sheet is hot straightened in a first straightening device, then cooled in a cooling device and then in a second straightening device. In the method of straightening and cooling a high-temperature steel sheet, the straightening of the high-temperature steel sheet by the first straightening device uses five or more continuous leveling rolls to reduce and drive a double-type or more multiple structure. The cooling of the high-temperature steel plate by the cooling device is performed vertically by one each.
A plurality of sets of constraining rolls, each of which is arranged by a set of rolls, bite the set of constraining rolls, and carry the hot steel sheet while injecting cooling water between upper and lower surfaces of the hot steel sheet between the constraining rolls. And a method for straightening and cooling a high-temperature steel sheet. 9. The straightening of a high-temperature steel sheet according to claim 8, wherein a leveling roll provided with a crown is used as a leveling roll used for correcting the high-temperature steel sheet by the first straightening device. And cooling method. 10. The invention according to claim 8, wherein, prior to the correction of the high-temperature steel sheet by the first straightening device, the width center line of the high-temperature steel sheet is aligned with the width center line of the straightening device. A method for correcting and cooling a high-temperature steel sheet, wherein the high-temperature steel sheet is corrected by the first straightening device later. 11. The invention according to claim 8, 9 or 10, wherein the cooling of the high-temperature steel sheet by the cooling device is performed because the drainage of the cooling water by the constraining rolls is incomplete. The water leaked to the top of the steel plate,
A method for straightening and cooling a high-temperature steel sheet, comprising removing the steel sheet by blowing it off with a jet fluid from one side end toward the other side end. 12. On-line in the process of producing a steel sheet by hot rolling, the shape of said steel sheet is hot straightened in a first straightening device, then cooled in a cooling device and then in a second straightening device.
In the method of straightening and cooling a high-temperature steel sheet, wherein the cooling of the high-temperature steel sheet by the cooling device is performed vertically by one each.
A plurality of constrained rolls, one set of rolls arranged one by one, bite with a plurality of constrained rolls, and while conveying the high-temperature steel sheet, cooling water is injected between upper and lower surfaces of the high-temperature steel sheet between the constrained rolls, and As a cooling method for the upper and lower surfaces of the high-temperature steel plate, the cooling is performed in the following step (h),
A method for straightening and cooling high-temperature steel sheets. (H) a long nozzle row in the width direction of the steel sheet having nozzle openings directed to the upper and lower surfaces of the steel sheet, injecting cooling water from the nozzle row, and forming an injection row formed by the cooling water thus injected. Number, the lower surface side of the steel plate is larger than the upper surface side, and the position in the steel plate length direction at which the cooling water injection row starts to collide with the steel plate between the constraining rolls, The upper and lower surfaces of the steel plate are adjusted so that the temporal change of the temperature in each minute portion of the upper and lower surfaces of the steel plate during the cooling process of the steel plate becomes the same with the center plane of the steel plate thickness as the symmetry plane. 13. A high-temperature steel sheet according to claim 8, 9, 10 or 11, wherein the cooling device cools the upper and lower surfaces of the high-temperature steel sheet in the following step (h). Straightening and cooling methods. (H) a long nozzle row in the width direction of the steel sheet having nozzle openings directed to the upper and lower surfaces of the steel sheet, injecting cooling water from the nozzle row, and forming an injection row formed by the cooling water thus injected. Number, the lower surface side of the steel plate is larger than the upper surface side, and the position in the steel plate length direction at which the cooling water injection row starts to collide with the steel plate between the constraining rolls, The upper and lower surfaces of the steel plate are adjusted so that the temporal change of the temperature in each minute portion of the upper and lower surfaces of the steel plate during the cooling process of the steel plate becomes the same with the center plane of the steel plate thickness as the symmetry plane. 14. A method for correcting and cooling a high-temperature steel sheet according to the invention of claim 13, wherein the cooling method for the upper surface side and the lower surface side of the high-temperature steel sheet is performed in the following step (i). (I) The cooling water jet line for cooling the upper surface side of the steel sheet is jetted from a single row of slit nozzles long in the width direction of the steel sheet, and the cooling for cooling the lower surface side of the steel sheet. The jet line of water is jetted from a plurality of nozzles long in the width direction of the steel sheet, and is jetted from a slit nozzle, a spray nozzle, a circular tube laminar nozzle, a circular tube jet nozzle with a conduit, or a perforated plate nozzle. That