JPH1110215A - Method for controlling wedge of hot rolled stock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely control a wedge on the outlet side of a finishing mill and camber on the outlet side of a roughing mill at the time of hot rolling within an allowable range. SOLUTION: In the case that the amount of a wedge on the outlet side of a finishing mill exceeds a predetermined threshold value or in the case that the amount of camber on the outlet side of a roughing mill exceeds a predetermined threshold value, the controlled amount of a roll gap which is enough to dissolve at least the amount which exceeds the threshold value of the amount of the wedge on the outlet side of the finishing mill is obtained from the relationship between the controlled amount of the roll gap and the variation of the wedge which are predetermined in accordance with thickness, width and a material. The amount of camber on the outlet side of the roughing mill is predicted based on this amount and by controlling the amount of leveling in the roughing mill so that the predicted amount of camber does not exceed the predetermined threshold value, the both wedge and camber are surely controlled within an allowable range without respectively taking the various factors of the generation of the wedge into consideration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a wedge of a hot-rolled material, which suppresses asymmetry between left and right plate thicknesses in a width direction, which is called a wedge of a hot-rolled steel strip in hot rolling.

[0002]

2. Description of the Related Art Generally, in hot rolling, a hot-rolled steel strip is called a wedge due to various asymmetries in the driving side and the working side of a rolling mill, that is, in the width direction of the hot-rolled steel strip. There may be a difference in thickness between the left and right plate width ends, and bending of the front and rear ends called cambers. Causes of wedges and cambers generated during hot rolling include horizontal rolling mills, left and right unevenness in the temperature distribution in the horizontal direction and inclination of the material to be rolled when biting into the vertical rolling mill, and differences in the left and right roll gaps of the horizontal rolling mill. The difference in thickness between the left and right sides of the slab itself, which is a rolled material, is mentioned, but these are complicatedly affecting,
Even if various data are processed and controlled, it is very difficult to reduce the wedge and camber to zero, and the installation cost of the sensor increases.

[0003] As a conventional method for controlling the camber, meandering, and wedge of a hot-rolled steel strip in hot rolling, a roll gap difference at both ends of a rough rolling mill stand during rolling and rolling data are determined based on rolling data. Side wedge amount is calculated, and the next stage stand is fed-forward controlled before biting of the rolled material so that the wedge at the next stage stand exit side becomes small according to the wedge amount, and the rough rolling mill exit side While reducing the wedge amount of the rolled material, the camber of the rolled material was measured between the rough rolling mill and the finish rolling mill, and the thickness of the rolled material and the wedge in the rolled material of the wedge were determined from the difference in roll gap between the camber and the post-rolling stand. Calculate the longitudinal changes of the rolls, and perform feedforward control during rolling to reduce the reduction and single reduction of the front stage of the finishing mill so that they are both small. How to both small wedge and camber stand outlet side of the rolled material (JP 57-206
511) has been proposed.

Further, the wedge amount and meandering amount of the rolled material before the rolling mill and the leveling offset amount of the rolling mill are obtained, and based on these, the meandering amount of the rolled material is suppressed within an allowable range, and A method of calculating the leveling amount of a rolling mill that minimizes the camber amount by an optimization method, and controlling the meandering amount by controlling the calculated leveling amount (Japanese Patent Laid-Open No. 3-57)
507) has been proposed.

Further, the camber amount and the meandering amount are measured at the entry side of the rolling mill to estimate the wedge amount at the exit side of the rolling mill, and the roll gap difference sufficient to eliminate the estimated wedge amount is obtained to control the work roll balance force. In addition, a method (Japanese Patent Laid-Open No. 6-7819) has been proposed to suppress the increase in camber and meandering.

In addition, the meandering amount and the wedge amount are measured before any rolling pass except the final pass of the rough rolling mill, and the wedge amount after the rough rolling is completed is predicted based on the measured meandering amount and the wedge amount. The combination of the roll gap differences in any two passes after the measurement is obtained and corrected, and the meandering amount and wedge amount of the rolled material after the final pass is measured, and the roll gap difference error in each of the two passes is determined from the measured values. And correcting the error in the two passes at the time of rolling the next material (Japanese Patent Laid-Open No. 4-9208).

[0007]

The above-mentioned JP-A-57-20
The method disclosed in Japanese Patent No. 6511 predicts the wedge amount from the roll gap difference and the rolling data such as the slab thickness, the draft, the sheet width, and the steel type. Therefore, when the rolled material is meandering, a prediction error occurs ( When the rolled material meanders, even if the wedge is zero, the rolling becomes asymmetrical in the left and right direction, so that the load applied to the left and right stands has a difference).

In the method disclosed in Japanese Patent Application Laid-Open No. 3-57507, the meandering amount and wedge amount are obtained by calculating from the left-right load difference of the front stand and the like.
As in the method disclosed in Japanese Patent Application Laid-Open No. 06511, there is a disadvantage that an error easily occurs.

Further, the method disclosed in Japanese Patent Laid-Open No. 6-7819 controls camber and meandering by reducing the output side wedge by correcting the roll gap difference. When the wedge amount of the rolled material itself is large, the camber is rather generated by the wedge control. That is, in the methods disclosed in the above-mentioned JP-A-57-206511, JP-A-3-57507 and JP-A-6-7819,
Since other camber and wedge generation factors such as non-uniform temperature distribution in the slab width direction and the amount of wedges on the entry side are not taken into account, there is a problem that errors are likely to occur.

Further, the method disclosed in Japanese Patent Application Laid-Open No. Hei 4-9208 improves the accuracy because the wedge error after the rough rolling is reflected in the next rolled material, but the meandering amount on the entrance side and the exit side is reduced. Measuring camber requires multiple sensors, complicates control, and does not measure the amount of wedges in the final product, causing wedges to occur in subsequent finishing mills. There is a point. In addition, the meandering control in the finishing mill is very costly because the shape sensor is arranged between all stands, and it is largely dependent on manual intervention by an operator. There is a problem in that meandering in the rolling mill cannot be suppressed, leading to spill trouble.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a reliable wedge detector on the exit side of the finishing mill and a camber detector on the exit side of the rough rolling mill of the hot rolling equipment. Another object of the present invention is to provide a method for controlling a wedge of a hot-rolled material, which can control a wedge and a camber in a hot rolling within an allowable range.

[0012]

According to the present invention, there is provided a method for controlling a wedge of a hot-rolled material, comprising the steps of finishing rolling of a hot rolling facility having a rough rolling mill comprising a plurality of stands or a plurality of passes and a finishing rolling mill comprising a plurality of stands. When the wedge amount of the rolled material measured by the wedge detector installed on the outlet side of the mill exceeds a predetermined threshold, or the camber amount of the rolled material measured by the camber detector installed on the outlet side of the rough rolling mill is When a predetermined threshold value is exceeded, in the method of controlling the leveling amount of the next rolled material in the rough rolling mill, the relationship between the roll gap control amount and the wedge change amount obtained in advance according to the sheet thickness, the sheet width, and the material. From at least determine the roll gap control amount sufficient to eliminate the amount exceeding the threshold of the wedge amount on the exit side of the finish rolling mill, and predict the camber amount on the rough rolling mill exit side based on this, and predicted Yanba amount is decided to control the leveling amount in a predetermined period not exceeding the threshold as rough rolling mill.

As described above, according to the present invention, the wedge of the hot-rolled product to be controlled is output from the wedge detector (usually measuring the wedge by a profile meter) installed on the output side of the finishing mill. Using a camber detector installed on the side (often a width gauge is installed on the output side, the camber amount can be calculated from the width meter output and line speed)
From the relationship between the roll gap control amount and the wedge change amount obtained in advance according to the sheet thickness, the sheet width, and the material, a roll gap control amount sufficient to eliminate at least the amount exceeding the threshold value of the output side wedge amount of the finishing mill is obtained. Based on this, the camber amount on the rough rolling mill exit side is predicted, and by controlling the leveling amount in the rough rolling mill so that the predicted camber amount does not exceed a predetermined threshold, various wedge occurrence factors are respectively determined. There is no need to consider it, and the control error is reflected in the next rolled material, so that neither the wedge nor the camber exceeds the allowable range. Further, when the wedge amount on the exit side of the finishing mill and the camber amount on the exit side of the rough rolling mill are both suppressed within the threshold value, the roll gap control is not performed. The frequency of manual intervention is reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 4 shows the rolling sequence of a hot-rolled material on the exit side of a finishing mill when a low-carbon ordinary steel slab is hot-rolled under the hot rolling conditions shown in FIGS. An example of a change in the wedge amount is shown. As shown in FIG. 4, the wedge amount of a general continuous hot-rolled material fluctuates periodically due to various factors, and the pre-rolled material has a predetermined threshold (± 20 μm in FIG. 4).
m), the next rolled material is within the allowable range (± in FIG. 4).
30 μm). Therefore, when the wedge amount of the pre-rolled material does not exceed the threshold value, the roll gap control of the rolled material need not be performed, and the roll gap control of the rolled material may be performed only when the wedge amount exceeds the threshold value.

When the wedge amount of the pre-rolled material on the exit side of the finishing mill exceeds the threshold value, the wedge threshold upper / lower limit value of the next rolled material ± W _TH The leveling amount δ _W1 , δ of the rough rolling mill aimed at the _TH
W2 is obtained by grouping the sheet thickness, the sheet width, and the material, and determining in advance the relationship between the roll gap control amount and the wedge change amount (for example, the correlation as shown in FIG. 3) corresponding to each group, From the relationship between the roll gap control amount and the wedge change amount of the group corresponding to the sheet thickness, sheet width, and material of the next rolled material, it can be obtained by the following equations (1) and (2). Further, when the camber amount on the exit side of the rough rolling mill of the pre-rolled material exceeds the threshold value, the camber threshold upper and lower limit values of the next rolled material ± ρ _TH The leveling amounts δ _C1 and δ of the rough rolling mill aimed at
_C2 can be obtained by the following equations (3) and (4).

Δ _W1 = ｛(W _N−1 × B _N / B _N−1 ) −W _TH ｝ × L / B _N Equation (1) (W _TH target leveling amount) δ _W2 = ｛(W _{N -1} × B _N / B _N-1 ) + W _TH ｝ × L / B _N (2) Equation (−W _TH Aiming Leveling Amount) δ _C1 = η (r, B) × (ρ _N-1 −ρ _TH ) × L... (3) Formula (ρ _TH Aiming Leveling Amount) δ _C2 = η (r, B) × (ρ _N-1 + ρ _TH ) × L... Formula (4) (-Ρ _TH target leveling amount) where L: distance between load application points, B _N-1 : width of pre-rolled material,
B _N : width of the rolled material, W _N-1 : wedge amount of the pre-rolled material, ρ
_N-1 : Pre-rolled material camber amount (curvature), W _TH : wedge threshold, ρ _TH: camber threshold (curvature), η (r, B):
The change coefficient of the wedge ratio (wedge / width) with respect to the camber curvature is shown. Also, the wedge sign is positive when the drive side is thick, the leveling amount is positive when the drive side rolling down direction is positive,
The sign of the camber amount is positive when it turns to the drive side.

In the control of the roll gap of the next rolled material, it is not always necessary to set the wedge amount on the exit side of the finishing mill to zero. Control may be performed so that both values fall within the threshold value. That is, in order to suppress the wedge of finishing mill exit side in the threshold, the leveling of the rough rolling machine may be carried out in the range of [delta] _W2 from [delta] _W1, also the camber quantity of the roughing mill delivery side to suppress within a threshold would leveling amount of rough rolling mill may be performed in the range of [delta] _C2 from [delta] _C1. Since the value that satisfies these conditions is usually not one, it is necessary to determine a target value in advance.

[0018] For example, in the case as much as possible of the casing 1 which want to reduce the leveling number, aim the threshold limit (W _TH) when the wedge amount is larger than the upper limit threshold (W _TH), the threshold limit (-W
_If it is smaller than _TH ), the leveling amount of the rough rolling mill is calculated and controlled by the following formula (5) so as to aim at the lower limit of the threshold value (−W _TH ). However, if the camber amount on the exit side of the rough rolling mill does not fall within the threshold value, the leveling amount of the rough rolling mill is changed. Conversely, in case 2 where the wedge amount on the exit side of the finishing mill is desired to be as small as possible even if the number of times of leveling increases, the leveling amount of the rough rolling mill is calculated and controlled according to the following equation (6) with the target set to 0. However, also in this case, it is assumed that the camber amount on the exit side of the rough rolling mill falls within the threshold value. In case 3 where the camber amount on the exit side of the rough rolling mill is desired to be as small as possible, the leveling amount of the rough rolling mill may be set to (δ _C1 + δ _C2 ) / 2 as shown in the following equation (7). However, also in this case, it is assumed that the wedge amount on the exit side of the finishing mill falls within the threshold value.

Case 1 δ = α · δ _W1 + (1−α) δ _W2 (5) where α = 1 if W _N-1 > W _{TH and} α = W _N-1 <W _TH 0 Case 2 δ = α · δ _W1 + (1−α) δ _W2 (6) where α = 0.5 if W _N-1 > W _{TH and} α = W _N-1 <W _TH 0.5 Case 3 δ = β · δ _C1 + (1−β) δ _C2 (7) where β = 0.5 if W _N−1 > W _{TH and} β = W _N−1 <W _TH β = 0.5

The target values of α and β in the above formulas are the sheet width, sheet thickness,
Efficient wedge control can be achieved by obtaining in advance according to the material. For example, in the case of a thick material in which the wedge does not cause much problem, the case 1 is selected. In the case of a material having a strict wedge accuracy such as a reroll material for cold rolling after slitting a hot-rolled coil, the case 2 is selected.
The case 3 is selected for a thin material that requires a threading property in a finish rolling mill.

[0021]

【Example】

Embodiment 1 Hereinafter, details of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram of the overall configuration of a hot rolling facility to which the present invention is applied, and FIG. 2 is a flowchart of a wedge control method of the present invention.

In FIG. 1, 1 is a rolled material (hot slab)
2 is a rough rolling mill for rough rolling, and 3 is a finishing rolling mill comprising first to sixth stands provided at a subsequent stage of the rough rolling mill 1, and a rough bar 4 roughly rolled by the rough rolling mill 1 is rolled to a predetermined sheet width. Then, the steel strip 5 is finish-rolled to a hot strip thickness. 6 is a roll gap control device for controlling the roll gap of the rough rolling mill 1, and 7 is a calculation device. Reference numeral 8 denotes a camber detector comprising a width gauge installed on the output side of the rough rolling mill 2, which detects the camber amount of the coarse bar 4 on the output side of the rough rolling mill 1 and outputs the detected camber amount to the arithmetic unit. Reference numeral 9 denotes a wedge detector comprising a profile meter installed on the exit side of the finishing mill 3, which is configured to detect the wedge amount of the hot steel strip 5 on the exit side of the finishing mill 3 and output the detected wedge amount to the arithmetic unit 7. ing.

The arithmetic unit 7 calculates the camber amount of the coarse bar 4 on the output side of the rough rolling mill 1 measured by the camber detector 8 and the heat on the output side of the finishing mill 3 detected by the wedge detector 9. When the wedge amount of the steel strip 5 is input, as shown in FIG. 2, a preset wedge threshold value (for example, 20 μm) is set.
m) and the input wedge amount of the hot steel strip 5 on the exit side of the finishing mill 3 are compared to determine whether the wedge amount exceeds the wedge threshold or a preset camber threshold (for example, 30 mm). / 10 m)
Is compared with the camber amount of the outgoing coarse bar 4 to determine whether the camber amount exceeds the camber threshold.

When the wedge amount or the camber amount does not exceed the threshold value, the arithmetic unit 7 inputs to the roll gap control unit 6 that the next rolled material will not be leveled.
On the other hand, if the wedge amount or the camber amount exceeds the threshold value, the arithmetic unit 7 determines the width, thickness, material, etc. of the next rolled material and the thickness, width, and material based on the target α. From the relationship between the roll gap control amount and the wedge change amount stored in advance, a relevant one is selected, and the leveling amount δ ₀ of the rough rolling mill 1 is determined from the relationship between the selected roll gap control amount and the wedge change amount according to (5). ) Or (6), the leveling amount of the rough rolling mill 1 that suppresses the camber amount on the output side of the rough rolling mill 1 calculated by the above equations (3) and (4) to be within the upper and lower limits of the camber threshold. δ _C1, δ _C2
And it is determined whether or not δ _C1 ≦ δ ₀ ≦ δ _C2 .

If δ _C1 ≦ δ ₀ ≦ δ _C2 , the arithmetic unit 7 outputs the leveling amount δ of the next rolled material δ = δ ₀ to the roll gap control device 6 and sets the leveling amount of the next rolled material to δ ₀ . Control. On the other hand, if δ _C1 ≦ δ ₀ ≦ δ _C2 , the arithmetic unit 7
Calculates and compares the absolute value of δ-δ _{C1 and} the absolute value of δ-δ _C2 based on the leveling amount of the next rolled material, and | δ-δ _C1
If | <| δ−δ _C2 |, it is determined whether 0 ≦ α ≦ 1 when the leveling amount of the next rolled material (δ = δ _C1 ), and if 0 ≦ α ≦ 1, , Roll gap control device 6
Then, the leveling amount δ = δ _C1 of the next rolled material is output, and the leveling amount of the next rolled material is controlled to δ _C1 . On the other hand, if 0 ≦ α ≦ 1, the arithmetic unit 7 inputs to the roll gap control unit 6 that the next rolled material will not be leveled.

The arithmetic unit 7 calculates | δ−δ _C1 | <| δ−δ _C2
Is not |, the leveling amount of the next rolled material (δ = δ _C2 ) is used to determine whether 0 ≦ α ≦ 1 and 0 ≦ α ≦
If it is 1, the leveling amount δ = δ _C2 of the next rolled material is output to the roll gap control device 6, and the leveling amount of the next rolled material is controlled to δ _C2 . If 0 ≦ α ≦ 1, the arithmetic unit 7
Is input to the roll gap control device 6 not to level the next rolled material, so that the next rolled material is not leveled.

With the above configuration, the arithmetic unit 7 detects the wedge amount W _N-1 of the hot steel strip 5 on the exit side of the finishing rolling mill 3 of the pre-rolled material detected by the wedge detector 9 and the camber detection. When the camber amount ρ _N-1 of the coarse bar 4 on the exit side of the rough rolling mill 1 detected by the device 8 is input, the wedge amount W _N-1 and the camber amount ρ _N-1 and each of the preset threshold values W _TH, [rho compares the _TH, wedge amount W _N-1 or camber amount [rho _N-1 is the threshold value W _TH, does not exceed the [rho _TH, the fact that following the rolled material in the roll gap control device 6 is not leveled Since the output is performed, the leveling control of the next rolled material is not performed.

On the other hand, when the wedge amount W _N-1 or the camber amount ρ _N-1 exceeds each of the threshold values W _TH , ρ _TH , the arithmetic unit 7 outputs data such as the sheet width, sheet thickness, and material of the next rolled material. Based on the target α of the wedge amount, the thickness, the width, and the relationship between the roll gap control amount and the wedge change amount stored in advance according to the material are selected, and the selected roll gap control amount and The leveling amount δ ₀ of the rough rolling mill 1 is calculated from the relation of the wedge change amount by the above equation (5) or (6), and the output side of the rough rolling mill 1 obtained by the above equations (3) and (4) is calculated. suppressing camber amount within the lower limit on the camber threshold [rho _TH rough rolling mill 1 of leveling the amount [delta] _C1, compared with the [delta] _C2, determines whether the _{δ C1 ≦ δ 0 ≦ δ C2} .

Then, the arithmetic unit 7 calculates that δ _C1 ≦ δ ₀ ≦ δ _C2
In this case, the leveling amount δ = δ ₀ of the next rolled material is output to the roll gap control device 6, so that the leveling amount of the next rolled material is controlled to δ ₀ . On the other hand, when δ _C1 ≦ δ ₀ ≦ δ _C2 is not satisfied, the calculating device 7 calculates and compares the absolute value of δ−δ _{C1 and} the absolute value of δ−δ _C2 based on the leveling amount δ of the next rolled material, If | δ−δ _C1 | <| δ−δ _C2 |, the leveling amount of the next rolled material (δ = δ _C1 ) is 0 ≦ α ≦ 1.
If 0 ≦ α ≦ 1, the leveling amount δ = δ _C1 of the next rolled material is output to the roll gap control device 6, so that the leveling amount of the next rolled material is controlled to δ _C1 . Is done. On the other hand, if 0 ≦ α ≦ 1, the arithmetic unit 7 outputs to the roll gap control unit 6 that the next rolled material is not leveled, so that the leveling control of the next rolled material is not performed.

The arithmetic unit 7 determines that | δ−δ _C1 | <| δ−δ _C2
Is not |, the leveling amount of the next rolled material (δ = δ _C2 ) is used to determine whether 0 ≦ α ≦ 1 and 0 ≦ α ≦
If it is 1, the leveling amount δ = δ _C2 of the next rolled material is output to the roll gap control device 6, so that the leveling amount of the next rolled material is controlled to δ _C2 . If 0 ≦ α ≦ 1, the arithmetic unit 7 outputs to the roll gap control unit 6 that the next rolled material is not leveled, so that the leveling control of the next rolled material is not performed.

Therefore, the target value α of the wedge amount of the hot steel strip 5 on the exit side of the finishing mill 3 and the target value β of the camber amount of the rough bar 4 on the exit side of the rough rolling mill 1 are determined by By making selections according to the sheet width, sheet thickness, and material, the control error of the wedge amount is reflected in the next rolled material without having to consider various causes of wedge generation, and the hot rolling on the exit side of the finishing mill 3 is performed. Neither the wedge amount of the steel strip 5 nor the camber amount of the rough bar 4 on the exit side of the rough rolling mill 1 exceed the allowable range. When the wedge amount of the hot steel strip 5 on the exit side of the finishing mill 3 and the camber amount of the coarse bar 4 on the exit side of the rough rolling mill 1 are suppressed within predetermined threshold values, leveling control is performed. Therefore, the frequency of manual intervention by the operator of the finishing mill can be reduced.

The value α of the wedge amount of the hot steel strip 5 on the exit side of the finish rolling mill 3 and the value β of the camber amount of the rough bar 4 on the exit side of the rough rolling mill 1 are determined by the values of the next rolled material. By making selections according to the sheet width, sheet thickness, and material, efficient wedge control of the hot steel strip 5 on the exit side of the finishing mill 3 can be performed. For example, when the wedge does not cause much problem, the case 1 is selected, and the case 1 is selected. When the requirement of the wedge accuracy is strict, such as a reroll material in which a hot-rolled coil is slit and then cold-rolled, the case 2 is used. In the case where the thickness is small and the sheet rolling property in the finishing mill 3 is required, the case 3 may be selected.

Example 2 A slab of low carbon ordinary steel having a width of 1500 mm and a thickness of 212 mm was roughly rolled to a coarse bar thickness of 50 mm by a rough rolling mill using the wedge control method of the present invention described in Example 1, and Finishing plate thickness 4.0mm, plate width 125 by finishing mill
In hot rolling to 0 mm, the relationship between the roll gap control amount (mm) of the rough rolling mill and the wedge change amount (μm) on the exit side of the finishing mill was determined. The result is shown in FIG.

As shown in FIG. 3, the roll gap control amount (mm) of the rough rolling mill and the wedge change amount (μm) on the exit side of the finishing mill have a correlation, and the leveling in the rough rolling mill is performed. It has been confirmed that by controlling the amount, the wedge on the exit side of the finishing mill can be controlled within a threshold value (for example, 20 μm), and the camber on the rough rolling exit side can be controlled within a threshold value (for example, 30 μm).

[0035]

The method for controlling wedges of a hot-rolled material according to the present invention uses a wedge detector installed on the exit side of a finishing mill and a camber detector installed on the exit side of a rough rolling mill. The control error is reflected on the next rolled material only when the value is outside the predetermined threshold value, and at least on the exit side of the finish rolling mill from the relationship between the roll gap control amount and the wedge change amount determined in advance according to the sheet thickness, the sheet width, and the material. A roll gap control amount sufficient to eliminate the amount exceeding the threshold of the wedge amount is obtained, and the camber amount on the exit side of the rough rolling mill is predicted based on the roll gap control amount, so that the rough camber amount does not exceed the predetermined threshold value. Since the leveling amount in the rolling mill is controlled, it is possible to reliably control both the wedge and the camber to an allowable range without considering various wedge generation factors.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the overall configuration of a hot rolling facility to which the method of the present invention is applied.

FIG. 2 is a flowchart of a wedge control method according to the present invention.

FIG. 3 is a graph showing a correlation between a roll gap control amount of a rough rolling mill and a wedge change amount on the exit side of a finishing rolling mill in Example 2.

FIG. 4 is a graph showing a relationship between a rolling order in hot rolling and a change in a wedge amount on the exit side of a finish rolling mill.

FIG. 5 is a graph showing a relationship between a rolling order in the hot rolling in FIG. 4 and a rolling load of a rough rolling mill.

FIG. 6 is a graph showing a relationship between a rolling order and a finished plate width in the hot rolling in FIG.

FIG. 7 is a graph showing a relationship between a rolling order in the hot rolling in FIG. 4 and a coarse bar thickness on the exit side of a rough rolling mill.

FIG. 8 is a graph showing a relationship between a rolling order and a finished plate thickness in the hot rolling in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rough rolling mill 2 Rolled material 3 Finish rolling mill 4 Rough bar 5 Hot steel strip 6 Roll gap control device 7 Computing device 8 Camber detector 9 Wedge detector

Claims (1)

[Claims] 1. A wedge of a rolled material measured by a wedge detector installed on an output side of a finishing mill of a hot rolling facility having a rough rolling mill having a plurality of stands or a plurality of passes and a finishing rolling mill having a plurality of stands. If the amount exceeds a predetermined threshold, or if the camber amount of the rolled material measured by a camber detector installed on the exit side of the rough rolling mill exceeds a predetermined threshold, the rough rolling mill of the next rolled material In the method of controlling the amount of leveling in the plate thickness, the width of the plate, the amount exceeding the threshold of the wedge amount on the exit side of the finishing mill at least from the relationship between the roll gap control amount and the wedge change amount determined in advance according to the material. A roll gap control amount sufficient to solve the problem is obtained, and the camber amount on the exit side of the rough rolling mill is predicted based on the roll gap control amount, and the ratio of the camber amount on the rough rolling mill is set so that the predicted camber amount does not exceed a predetermined threshold value. A method for controlling a wedge of a hot-rolled material, comprising controlling the amount of belling.