JPH049207A - Control method of bend and wedge of rolled stock in hot rough rolling and hot rough rolling equipment - Google Patents

Abstract

PURPOSE:To improve the quality and yield of products by measuring wedge quantity of a rolled stock after the completion of each control pass of two passes, determining the set error of nonuniform rolling-down of the two passes and correcting the error by two passed when rolling the next stock. CONSTITUTION:In the rough rolling process by plural passes or with plural stands 1, 2, 3, 4, the transverse bend quantity and the wedge quantity of the rolled stock 5 before rolling pass are measured with a bend detector 6 and wedge detectors 7, 8, 9. From the measured results, the transverse bend quantity and the wedge quantity after the completion of rolling are predicted and the transverse bend quantity and the wedge quantity are controlled by performing the nonuniform rolling-down of two passes so as to cancel them. The wedge quantity of a rolled stock 5, after the completion of each control pass of the two passes is measured, the set error of nonuniform rolling-down of the two passes is determined and the error is corrected by two passes when rolling the next stock. In this way, the efficiency of rolling work can be raised.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control method and rough rolling equipment that can prevent bending of a plate and remove wedges in a rough rolling process of hot rolling equipment.

[Prior Art] Generally, continuous hot rolling equipment is comprised of a rough rolling mill group and a finishing rolling mill group, each consisting of a plurality of stands. Due to imperfect equipment maintenance in these rolling mills, the upper and lower rolls may not be parallel, or the elongation constants of the left and right mills may differ, leading to the possibility of one-sided reduction occurring during rolling. However, since continuous hot rolling equipment has a large number of rolling mills, it is difficult to maintain and manage all of these rolling mills so that they do not become asymmetrical, and it is difficult to maintain them so that they do not become asymmetrical. This often results in bends or wedges in the plate after rolling. Such bends and wedges will inevitably reduce the quality of the finished product, and often cause meandering of the plate, especially in finishing mill rows, leading to accidents. In finishing rolling mills, the thickness of the plate is thin and it is difficult to restrain the plate from side to side, so a technique has been put into practical use to prevent meandering by adjusting one side of some stands. However, since this control requires very high speed and delicate adjustment, there is a problem that the control becomes uncontrollable if there is a large disturbance such as bends or wedges that occur in the rough rolling mill. On the other hand, in rough rolling mill rows, the plate is thick and the left and right sides are restrained by side guides, edge rolling mills, etc., so meandering may not be a big problem, but bends and wedges may occur, and if left untreated, it will be difficult to finish. It is important to prevent bends and wedges from occurring as much as possible during the rough rolling stage, as this can cause meandering.

In order to prevent such bending and wedges, it is important to carry out sufficient accuracy control of the rolling mill equipment and to avoid performing asymmetrical rolling. However, it is not easy to implement this reliably in a large number of rolling mills, and none of them can cope with the rolling of slabs that originally have wedges. Therefore, various proposals have been made for methods of controlling board bending, and the representative ones include moving the edger roll or using different circumferential speeds, as in Japanese Patent Publication No. 63-29607 or No. 64-4845. There is a way to directly correct curvature by doing this. Also, as disclosed in JP-A-55-75811, there is a method in which the amount of bending of the rolled material is measured just before the final pass, and one side reduction adjustment is made in the final pass so that the bending is O. Unexamined Japanese Patent Publication No. 6 as a control method
As disclosed in No. 2-89510, the amount of bending and wedge of the rolled material after the i-th pass, which is an intermediate pass, is estimated or measured, and both the bending and wedge of the rolled material after the i+2th pass are O. A single-side pressure adjustment method in an intermediate pass for performing single-side pressure adjustment in the i+1th pass is also presented.

[Problems to be Solved by the Invention] As mentioned above, the wedge bends during rough rolling, and if the wedges cannot be controlled at the same time, it will cause meandering during finish rolling in the subsequent process. However, the method using the edger roll does not have the function of correcting the wedge even if the bend is corrected.

Next, there is a problem with the method of one-sided reduction adjustment, or the method of first adjusting one-side reduction in the final pass, in that a wedge is generated by correcting the bend. Further, even the method of adjusting one-side pressure reduction using an intermediate pass still does not have sufficient control accuracy.The reason for this will be explained in detail below.

For convenience of explanation, the rough rolling equipment includes a first stand 1, a second stand 2, a third stand 3, and a fourth stand as shown in FIG.
It consists of a rolling mill row consisting of stands 4, of which the first stand performs reverse rolling, and the second to fourth stands perform reverse rolling.
It is assumed that this is a process in which rolling is performed continuously without performing reverse rolling in the stand. In the figure, 5 is a slab which is a rolled material, 5' is a rolled material at the time when rolling on the second stand has finished, and 5'' is a sheet bar that has finished rolling on the final stand 4. The inventors conducted an experiment in the process of rough rolling a slab 200 mm thick x 102 h wide into a 3 hm thick sheet bar using the rough rolling equipment as described above, and obtained the following results. .

■When one side reduction adjustment was not performed on either stand, the sheet bar 5'' after rough rolling was bent approximately 7011 mm toward the operator side and a thin wedge of 0.02 mm was generated on the operator side. The cause is unknown, or it is thought to be due to a difference in the rigidity of the left and right mills of one of the stands, or an imbalance in the parallelism of the upper and lower rolls.

■Therefore, when adjusting the single pressure lower stage amount e2 of the fourth stand 4 that performs the final pass, the bending amount of the seat bar 5'' is Ys
As shown in FIG. 2, the result was that the curve changes almost linearly. Furthermore, the relationship between e2 and the wedge amount Ws of the seat bar 5'' was also found to change almost linearly as shown in FIG.
It can be seen that in order to eliminate the bending of the seat bar 5'' by adjusting the single-side pressure lowering amount e2 of the stand, it is sufficient to perform a single-side pressure that closes the operator side by about 0.18 m.However, at this time, from Fig. 3 As is clear, when 02 is set as described above, the amount of wedge produced in the seat bar 5'' is approximately 0.04 mm, which is thinner on the operator side. Therefore, it is understood that this method cannot control the amount of bending and the amount of wedge at the same time.

(2) Next, under the same conditions, an experiment was conducted in which the third stand 3 was lowered one-sidedly, with the one-sided lowering stage e2 of the fourth stand set to 0. As a result, the relationship between the single pressure lower stage e of the third stand 3 and the bending amount Ys of the seat bar 5'' is determined as shown in FIG. 4, and the relationship between e8 and the wedge amount Ws of the seat bar 5'' is determined as It was obtained as shown in the figure. Therefore, according to FIG. 4, in order to eliminate the bending that occurs in the seat bar 5'', it is necessary to set the single-side pressure lower stage of the third stand 3 so as to open the operator side by about 1.2 mm. According to Figure 5, the seat bar 5'' has approximately 0.11ei
It can be seen that a thick wedge will occur on the operator's side. In this way, it is impossible to control bending and wedge at the same time by adjusting one-side pressure on the intermediate stand. This result is from the above-mentioned Japanese Patent Application Publication No. 62
This may be contradictory to what is stated in -89510, but in the said invention, it is thought that the wedge becomes 0 approximately by setting the single pressure lower step setting in the final pass to 0,
In reality, the rolled material may be bent or wedged during the previous pass, or the rolling mill may be asymmetrically deformed during rolling during the final pass. This is because a wedge will occur.

Furthermore, there is another reason why the control accuracy is not improved in the conventional single-pressure control method described above. The reason is that the rolling mill itself that performs the single-rolling step setting has an error in the accuracy of the equipment, and it is extremely difficult to set the single-rolling step as desired. Even when such errors in equipment accuracy are measured, there are large variations, and it is extremely difficult to quantitatively capture them.

As described above, none of the conventional methods can control the bend and the wedge at the same time. The present invention has been made in view of these circumstances, and implements control such that both bending and wedge are zero in the rough rolling process, thereby supplying a sheet bar without bending or wedge to the finishing rolling process, Furthermore, the purpose is to suppress meandering during finish rolling.

[Means for Solving the Problems] The present invention as set forth in claim 1 provides a rough rolling process consisting of multiple passes or multiple stands, in which horizontal bending of a rolled material is prevented before any rolling pass except the final pass is performed. and wedge amount, predict the horizontal bending amount and wedge amount of the rolled material after the completion of rough rolling from the measurement results, and calculate the one-sided lower stage quantitative determination in any two passes after the measurement to cancel this. determining the combination, and determining the bending and wedge control method for the rolled material that performs one-side reduction rolling in the two passes, and measuring the amount of wedge of the rolled material after each control pass of the two passes, respectively; From the deviation between the measurement result and the predicted value of the wedge amount in each of the two passes predicted from the measurement result, the one-side rolling lower step error in each of the two passes is calculated, and the error is determined in the two passes when rolling the next material. This error is corrected.

The present invention as set forth in claim 2 provides a hot rough rolling facility having two or more stands of rough rolling mills, at least the last stand being a non-reversing type rolling mill, and any rolling mill other than the last stand. A front-stage wedge detector is installed at the entrance side of the mill to detect the amount of wedge in the rolled material, and a front-stage chamfer detector is installed to detect the amount of lateral bending of the rolled material. The first and second rear wedge detectors are installed on the exit side of each rolling mill in any two stands located at From the measurement results, predict the amount of lateral bending and wedge amount of the rolled material after completion of rough rolling, find a combination of single rolling lower stage determination in any two stands after the measurement that cancels this, and further calculate the Based on the deviation between the measurement results of each of the second-stage grinding detectors and the predicted values of the wedge amount in each of the two stands predicted from the measurement results of the front-stage wedge detector and the front-stage flatness detector, A computing device is provided for determining the one-side rolling lower stage determination error in each of the two stands, and is additionally provided in each rolling mill of the two stands, and the one-side rolling lower stage determination error in the two stands calculated by the computing device is used to determine the one-side rolling lower stage determination error in the two stands. The rolling stock is further provided with a reduction control device which uses the one-side reduction step setting error calculated by the arithmetic unit to correct the error in the two stands when rolling the next material.

[Operation] The control principle according to the present invention will be explained in detail. Here again, examples of the above-mentioned rough rolling equipment and operating conditions will be explained. The inventors of the present invention have focused on the fact that the slopes of the straight lines shown in FIGS. It was found that it can be controlled independently. That is, the bending control amount △Y and wedge control amount △W generated in the seat bar 5'' are the single pressure lower stage quantity e of the third stand 3.
, and the single pressure lower stage quantity e2 of the fourth stand 4 is expressed as follows.

△Y ” C,et + Chew
...' (1)△W =C3ex + C,e,
"" (2) In the above formula, 01 is the slope of the experimental line shown in Figure 4, C6 is the slope of the experimental line shown in Figure 2, C3 is the slope of the experimental line shown in Figure 5, C4
are constants representing the slopes of the experimental lines shown in FIG. 3, and these constants are determined from FIGS. 2 to 5 as shown in Table 1. In formulas (1) and (2) and Table 1, the positive and negative values of the numerical values indicate the bending control amount △Y when the bend is toward the operator's side, the wedge control amount ΔW when the wedge is thicker on the operator's side, and the one-sided reduction amount (el, C2). ) are defined as positive if the operator side opens. I will omit the mathematical proof, but (1), (2)
By using the formula and the values in Table 1, it is possible to independently and freely control the amount of bending and the amount of wedge by selecting an appropriate combination of values of e 1t 82. Therefore, if you know the amount of bending and wedge of the seat bar 5'' when no control is performed in advance, you can make both the bend and wedge of the seat bar 5'' O by performing one-side pressure down control to cancel this. The present invention utilizes this principle.

Next, in order to perform the above control, it is necessary to find the amount of bending and wedge of the seat bar 5'' when the control is not performed as described above. It would be better to install a bend detector and a wedge detector to directly measure the sheet bar during the rolling of the previous slab and predict that the next slab will have the same amount of bend and wedge, but this method does not work. There is a drawback that bends and wedges caused by the rolled material cannot be predicted, such as when there is a wedge in the slab 5.Therefore, in the present invention, between the second stand 2 and the third stand 3, there is a A method is used in which wedge detectors are installed, the amount of bending and the amount of wedge of the rolled material are measured by these detectors, and the amount of bending and wedge of the sheet bar 5'' is predicted based on this. As for this prediction method, the present inventors analyzed operation data on an actual rolling line and found that if the single rolling lower stage setting of the third stand 3 and the fourth stand 4 is not performed, the The amount of lateral bending Y2 and wedge amount W2 of the plate measured on the rolled material 5' and the amount of lateral bending Ys and wedge amount Ws of the sheet bar 5'' measured at the exit side of the final stand 4 are approximately as follows. It was found that the relationship holds true.

Ys = CsYg + C6112-(3) Ws =
CvYt÷cewt - (4)
(3) (In formula 43, 05 to C6 are constants obtained by regression of the experimental results, and their specific values were determined as shown in Table 2. The positive and negative values of the values in the table were determined in the same manner as described above. That is, Y2. was measured at the exit side of the second stand 2 during rolling of a certain rolled material.
By using the value of W, the amount of bending Y after the rolling of the rolled material at the final stand 4 can be determined before the rolling starts at the third stand 3.
s, Ws can be predicted using equations (3) and (4). So, now the bend after the rolling of the final stand 4,
In order to make both wedge amounts 0.

+3) Ys, Ws determined by formula (4) (1)
The third stand 3 and the fourth stand 4 are arranged so that ΔY and ΔW expressed by the formula (2) are both canceled.
What is necessary is to set the one-side pressure lower stage quantities e1 and C2. These values can be easily obtained by solving the following simultaneous equations obtained by setting ΔY = -Ys and Δwcony-s.

C1e+ + Cae2” (C3Y2” C6W
2) ...(5)C,, e+ + C12g
” (CtY* + C3W2) −<6) Next, send this calculation result to the third stand 3 and fourth stand 4, and add the one-sided pressure reduction amount e□ found by climbing these stands to C2. After setting, the third and fourth stands
If the stands are rolled one after the other, it is possible to obtain a sheet bar that is finally bent and has no wedges.

However, in reality, if the above control is performed, the bending will occur.
There are cases where it is not possible to control both wedges with sufficient precision.

To use the example above, this may be due to the imbalance of the upper and lower rolls due to incomplete equipment maintenance in the third stand 3 and the fourth stand 4, or the difference in the rigidity of the left and right mills, and it is not necessarily possible to achieve the desired one-sided pressure. This is because there are many cases where it is not possible to get the lower dan. Therefore, in the present invention, during the above-mentioned controlled rolling, first and second rear-stage wedge detectors are installed on the exit side of each of the third stand 3 and fourth stand 4, and the wedge amount of the rolled material is measured by these detectors. , this allows the third stand 3
It also has a function to further improve control accuracy by determining the one-side rolling step error for each of the and fourth stands 4 and correcting this when rolling the next material.

A specific example of how to obtain the above-mentioned single pressure lower step error will be explained below. If we assume that the resulting single-rolling errors due to the imbalance of the parallelism of the upper and lower rolls of the third stand 3 and the fourth stand 4 and the difference in left and right mill rigidity are △e1 and △e2, respectively, then the single-rolling equipment for these stands is When the above el and C2 are set,
In reality, due to the error in determining the one-side pressure lower step, the above-mentioned one-side pressure reduction amount becomes C1+Δe1 and C2+Δe2, respectively. Next, through experiments similar to those described above, the present inventors found that the wedge amount W3 of the rolled material at the exit side of the third stand 3 can be expressed as follows using Y2, W2, and el. .

W3m Ct'Yz + C8'W2 + C*'e+
+++ (7) Here, C,,C,',C
6' is a constant determined experimentally, and its specific values are shown in Table 3. Therefore, when there is an error in the one-side pressure lowering stage setting of the third stand 3, the actual result of the third stand 3
The wedge amount W1 of the rolled material measured on the exit side deviates from W3 in equation (7). If this deviation is △W3, then △
W3 is expressed as follows.

△L ” W31@ −L ” Cy'Yz + Ca
'W2 +C3' (e, + △e+3-(Cv'Y2
+C6'W2+ C:+'e+)=C3'△e+
-18> Therefore, by measuring the wedge amounts W and m of the rolled material at the exit side of the third stand 3, it becomes possible to obtain the one-sided reduction error △e□ of the third stand 3 from equation (8). .

Next, the wedge amount Wsm of the sheet bar 5'' after rough rolling, which is measured as a control error, is expressed by the following formula.

Wsn = C+(e++△e+) ÷C4(e2+△
e2)+cyy2÷C3W2...
・(9) Substituting equation (6) into this equation, Wsm = C, Δe, +C, Δe2 −
(to) Therefore, if the wedge amount of the sheet bar after rough rolling is measured and △e1 is found by the above method, then (10
) equation, the one-side pressure measurement error Δe2 of the fourth stand 4 is determined.

If the standard for determining the single rolling step of the third stand 3 and the fourth stand 4 is corrected according to Δe I and Δe2 obtained in this way, the third stand 3 and the third stand 4. The single pressure lower stage setting error of stand 4 will be erased. Therefore, by repeatedly performing this control when rolling the next slab, control accuracy can be further improved.

By adopting such a configuration, the present invention reduces both the bending and wedge of the sheet bar after rough rolling, thereby facilitating meandering control during finish rolling, and improving product quality and operational efficiency. I'll come.

[Example] FIG. 1 is a schematic diagram showing one embodiment of a rough rolling equipment according to the present invention. In FIG. 1, 1 is a first stand rough rolling mill, 2 is a second stand rough rolling mill, 3 is a third stand rough rolling mill, and 4 is a fourth stand rough rolling mill. Among these, at least the third stand 3 and the fourth stand 4 are continuous rolling mills that do not perform reverse rolling. Further, 5 is the slab which is the raw material before rolling, 5' is the rolled material after the second stand rolling, and 5'' is the sheet bar after rough rolling. is provided with a front wedge detector 7 which is a combination of a conventionally known optical front side bend detector 6 and a conventionally known laser distance meter, and the wedge detector 7 is also installed on the exit side of each of the third stand 3 and the fourth stand 4. First and second rear wedge detectors 8.9 having the same configuration as the detector 7 are provided.Furthermore, a third stand is provided based on the detection results of the bend detector 6 and the wedge detector 7.8.9. A calculation device 10 for calculating the single pressure lower step constant value of the third stand 3 and the fourth stand 4 is installed at an appropriate place, and furthermore, the third stand 3 and the fourth stand 4 each have a single pressure lower step setting value according to the calculation result. A reduction control device 11 is installed in each case.

Next, an example in which control is performed using this device will be described.

According to an experiment conducted on a different occasion than the one mentioned above, the first
If the wood grain slab is not controlled and rolled as it is until it reaches the fourth stand, the sheet bar 5'' after rolling will have a bend of about 87 mm toward the operator and about 0.
．． The result was that either the 07mm operator side or a thick wedge occurred. The amount of bending at the exit side of the fourth stand at this time was measured using a simple experimental measuring device (not shown).

Next, the bending and wedge of the second slab were controlled according to the above procedure under the same conditions.

First, the rolled material 5' after rolling on the second stand 2 is detected by a bend detector 6 and a wedge detector 7 for a length of 34.5 m.
A bend toward the drive side of m and a thin wedge amount of 0.34 mm on the operator side were detected. Therefore, these results were sent to the calculation device 10, and the single-pressure lower stage quantitative e of the third stand 3 and the single-pressure lower stage quantitative e2 of the fourth stand 4 were calculated using the calculation formulas (5) and (6). The calculation result is e,
-0,336mm, ea: -0,156mm. Then, the calculation results are sent to the reduction control device 11 installed in each of the third stand 3 and the fourth stand 4, and the third stand 3 is opened on the operator side by 0.3361!1.
After the fourth stand 4 was set to be rolled down on one side so as to close the operator side by 0.156 mm, rolling at the third and fourth stands 4 was slowed down.

By performing this control in this way, the bends and wedges that occur on the intermediate stand are both reduced on the exit side of the 4th stand, and finally the sheet bar 5'' after the completion of rolling on the 4th stand is on the operator side. The amount of lateral bending of 7.11 and the amount of wedge that is 0.04mm thick on the operator side (results detected by wedge detector 9) remained. Also, the wedge at the exit side of the third stand was 0.189w11 thick on the operator side. (detection results by the wedge detector 8).Therefore, these wedge amount detection results are sent again to the arithmetic unit 1o, and the third
When determining the single pressure lower step error of stand 3 and fourth stand 4, the results are △e1・0.2851m, △e2・−0,0
It was 61sa.

Next, when the third slab is rolled on the second stand 2, a bend detector 6 and a wedge detector 7 are detected on the entrance side of the second stand.
As a result, the rolled material at the exit of the second stand had 37.4aa.
A bend towards the + drive side and a 0.34mm operator side or thin wedge were detected. Then, in the same way as above, when the single pressure lower stage quantities e l and e 2 of the third stand 3 and the fourth stand 4 are calculated using equations (6) and (7) using the calculation device 10, the result is el・[1,320 mm , e 2 knee was 0.145 m5. Therefore, this time, this one-sided lower stage quantity was determined during the second slab rolling, △er, △e
2 is subtracted from each value e, ・0.035mm,
After correcting e a = -0.206 nm and setting each piece reduction amount of the third stand 3 and the fourth stand 4 at this value, rolling was continued. In this third rolled material, a sheet bar with almost no bends or wedges was obtained, confirming the effect of the present invention.

In the above description, the rough rolling equipment shown in FIG. 1 is an embodiment of the present invention, and changes can be made without departing from the spirit of the present invention. For example, the present invention is not limited to whether the rolling mill is a double type or a quadruple type. Also, the number of stands may be different. For example, in a rough rolling facility having five rolling mills, the milling detector and the wedge detector are installed between the third stand and the fourth stand, and the wedge detector is installed on the exit side of each of the fourth and fifth stands. All you have to do is install the 4th and 5th stands and correct the one-side pressure.

Since the constants shown in Tables 1 to 3 are expected to be different depending on the type and arrangement of rolling mills, it is necessary to experimentally determine the constants for each piece of equipment. Further, in this example, the second and last stand in the row of rough rolling mills is used as the one-reduction control stand, but in principle, control is possible even if the other two stands are used as the control stands. For example, in a rough rolling facility having five rolling mills, a side bend detector and a wedge detector are provided on the entry side of the third stand, and wedge detectors are provided on the exit side of each of the third and fifth stands.
It is also possible to set the third stand and the fifth stand in a single-pressure position.

Note that the aspects of the bend amount detector and the wedge amount detector are not limited to those of this embodiment.

[Effects of the Invention] According to the present invention, it is possible to prevent both bending and wedging of the sheet bar that occurs in the rough rolling process, and it is also possible to suppress meandering in the finishing rolling process, which is a subsequent process. Therefore, it has the excellent effects of increasing rolling efficiency and improving product quality and fractionation.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram schematically showing an example of equipment according to the present invention, Fig. 2 is an experimental diagram showing the relationship between the amount of one-side reduction of the fourth stand and the amount of bending of the seat bar, and Fig. 3 is an explanatory diagram showing the relationship between the amount of one-side reduction of the fourth stand and the amount of bending of the seat bar. An experimental diagram showing the relationship between the amount of one-side reduction and the amount of wedge of the seat bar. Figure 4 is an experimental diagram showing the relationship between the amount of one-side reduction of the third stand and the amount of bending of the seat bar. FIG. 3 is an experimental diagram showing the relationship between the amount of one-sided reduction and the amount of wedge of the seat bar. 1... 1st stand rough rolling mill, 2... 2nd stand rough rolling mill, 3... 3rd stand rough rolling mill, 4... 4th stand rough rolling mill, 5... Rolled material (Slab), 5'...Rolled material (in the middle of rolling), 5''...Rolled material (sheet bar), 6...Bending detector, 7... Wedge detector, 8... First Rear stage wedge detector, 9... 2nd @ stage wedge detector, 1o... Arithmetic device, 11... Lowering control device.

Claims (2)

[Claims] (1) In a rough rolling process consisting of multiple passes or multiple stands, measure the amount of lateral bending and wedge amount of the rolled material before performing any rolling pass except the final pass, and based on the measurement results, after the rough rolling is completed. predicting the amount of lateral bending and the amount of wedge of the rolled material, and finding a combination of one side reduction settings in any two passes after the measurement that cancels this,
Accordingly, there is provided a bending and wedge control method for a rolled material that performs one-side reduction rolling in the two passes, in which the wedge amount of the rolled material is measured after each of the two passes is completed, and the measurement results and 2 predicted from the measurement results
The heating method is characterized in that the one-side reduction setting error in each of the two passes is determined from the deviation from the predicted value of the wedge amount in each pass, and the error is corrected in the two passes when rolling the next material. Method for controlling bending and wedge of rolled material during rough rolling. (2) Hot rough rolling equipment that has two or more rough rolling mills, with at least the final stand being a non-reversing rolling mill, each installed on the entry side of any rolling mill other than the final stand. It is equipped with a front-stage wedge detector that detects the wedge amount of the rolled material and a front-stage bend detector that detects the amount of lateral bending of the rolled material, and a front-stage wedge detector that detects the amount of lateral bending of the rolled material. First and second rear wedge detectors are installed on the exit side of the rolling mill to detect the wedge amount of the rolled material, and the measurement results from the front wedge detector and the front bend detector determine whether rolling after rough rolling has been completed. Predict the amount of lateral bending and wedge amount of the material, find a combination of one-sided reduction settings in any two stands after the measurement to cancel this, and then measure the first and second post-bending detectors. 2 predicted from the results and the measurement results of the front wedge detector and the front bend detector.
A calculation device is provided for determining the one-side rolling reduction setting error in each of the two stands from the deviation from the predicted value of the wedge amount in each of the stands, and further provided incidentally in each rolling mill of the two stands, the calculation device The setting amount of one-side reduction in the two stands calculated by is used to set the one-side reduction in the two stands, and the one-side reduction setting error calculated by the calculation device is used to determine the error in the two stands when rolling the next material. Hot rough rolling equipment characterized in that it is equipped with a rolling reduction control device that corrects.