JPH09262612A - Plane shape controlling method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively and precisely control a plane shape and to also execute the feed-back control on a plate during rolling. SOLUTION: This is a plane shape controlling method on a thick plate rolling to rectangularly make a plate edge rear end by using edging rolls 14a, 14b, the plate width after rolling is measured with a plate width detector 15, the width deformed amount of the plate edge rear end is calculated with a width deforming amount arithmetic part 16 from the measured value, and the calculated width deformed amount and a set width deforming amount of every pass- schedule which is obtained with a pre-calculation and stored in an arithmetic part 17 are compared and calculated with the arithmetic part 17. Based on this comparison calculated result, the rolling reduction of the edging rolls 14a, 14b on the next pass schedule is controlled, the plate shape is controlled effectively and precisely, and the feed-back control onto the plate during rolling is realized also.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plane shape control method for plate rolling and a plane shape control device for plate rolling.

[0002]

2. Description of the Related Art Generally, a plate rolling mill is composed of one finishing rolling mill,
Alternatively, it is composed of a combination of a rough rolling mill and a finish rolling mill. In recent years, width reduction rolling mills have been actively installed in order to make thick plate products as close to rectangular as possible for the purpose of improving yield.

An example of a thick plate shape defect will be described with reference to FIG. In general, if the final width plate product after rolling has a small width-to-width ratio (product width / slab width), tongue-shaped crops and claw-like leading and trailing edge width accuracy defects occur, as shown in Fig. 4 (a). ,
On the other hand, if the width-to-width ratio is large, a fishtail-shaped crop and a trough-shaped front / rear end width accuracy defect occur, as shown in FIG. 4B. Further, it is also known that the poor plate width accuracy as shown in FIG. 4C is caused by heating furnace / burn unevenness (skid marks). Furthermore, since there is a difference in width spread in the plate thickness direction on the side surface of the slab during horizontal rolling,
The curling up as shown in (d) may occur.

Since such a defective planar shape of the product causes a significant decrease in yield, various measures have been considered to make the planar shape of the product closer to a rectangle. As a powerful means among these, there is a method using a width rolling mill.

An example of controlling the planar shape of the thick plate front and rear ends by the width rolling mill will be described with reference to FIG. The slab 1 undergoes forming and rolling mainly for the purpose of making the plate thickness uniform as the first step, and then is rotated 90 degrees in a horizontal plane and width-rolled in the length direction by the width rolling mills 3a and 3'a. Horizontal tenter rolling (Fig. 5
Then, instead of rotating the slab 1 90 degrees, change the rolling direction to 9
(It is shown rotated by 0 degrees). This is further rotated 90 degrees in the horizontal plane, and width-rolled by the width-rolling machines 3b and 3'b in the width direction, and then finish-rolled.

In the planar shape control example shown in FIG. 5, the planar shape of the front and rear ends is controlled by changing the width reduction amount.

FIG. 6 and FIG. 7 show a schematic state of the planar shape of the rear end of the plate front. FIG. 6 shows a case where there is no edging process, that is, only horizontal rolling, and FIG. 7 shows a case where edging is applied.

The horizontal axis in each of FIGS. 6 and 7 indicates the rear end of the plate.
Sum of the length (ΔL) (ΔL_Top+ ΔL _Bottm), In FIG.
The vertical axis in FIG. 7 is the plate width deviation (ΔW) between the rear end of the plate front and the center
Sum of (Δω_Top+ Δω_Bottm). V in the figure is an edge
Rolling path, H is horizontal rolling path, DBT is
Shape rolling process, DW finishing width rolling process, DAT finishing
DF shows the front stage of the rolling and DF shows the finishing process.
You.

When there is no edging step, that is, when only horizontal rolling is performed, the elongation in the rolling direction at the central portion of the strip width is larger than that at the end portion of the strip width and at the widthwise direction than at the central portion in the strip longitudinal direction at the trailing edge of the sheet leading edge. The amount of spread increases. On the other hand, when edging is applied, the elongation in the rolling direction at the center of the sheet width is smaller than the elongation at the edge of the sheet width in the rolling direction at the trailing edge of the sheet front, as shown in the third quadrant in the figure, and compared with the center in the sheet longitudinal direction. Then, the width tends to decrease. In the actual production process, it is necessary to select the optimum edging amount such that the plate front and rear ends are rectangular in consideration of the above-described deformation amount.

FIG. 8 shows a line configuration of a typical current thick plate mill. The slab 1 delivered from the heating furnace is
Rough rolling process (edger 3a, 3'a, horizontal rolling mill 2a)
Then, it is processed in the finish rolling process (edgers 3a, 3'b, horizontal rolling mill 2b) to be formed into a predetermined shape and dimension, and the material is built in by the accelerating cooler 30.
Then, the shape is corrected by the hot leveler 31, and predetermined data such as the crop and the width of the plate front and rear edges are measured by the automatic plate shape measuring device (ASM) 32, and then the plate is carried into the cooling bed 33. The information on the crop of the front and rear edges of the plate obtained by the automatic plate shape measuring instrument 32 is used for the plate cutting in the shear line in the subsequent process, and is also used for controlling the plane shape, that is, for adjusting the edging amount. .

[0011]

However, the ASM
The data from 32 is the data of the plate that has already been rolled, and in reality, complicated data processing is required to obtain the crop length and width variation amount, and the accuracy is not so good. .

The present invention has been made in view of the above circumstances, and it is possible to efficiently and accurately control a flat shape and also to perform feedback control to a plate during rolling. An object is to provide a shape control device.

[0013]

A plane shape control method for plate rolling according to the present invention for achieving the above object is a plane shape control method for plate rolling in which a plate front / rear end is made rectangular by using an edging roll. Therefore, the strip width after rolling is measured, the width variation amount of the strip front end is calculated from the measured value, and the width variation amount and the preset width variation amount for each pass schedule calculated in advance are calculated and compared. It is characterized in that the amount of reduction of the edging roll of the next pass schedule is controlled based on the calculation result.

Further, the set width variation amount Δω for each pass schedule is calculated by the following formula, and the set width variation amount Δω after the final pass schedule is set to 0. Δω = (Δω _Top + Δω _Bottm ) / 2 where Δω _Top is the plate _width deviation between the plate front end and the plate center Δω _{Bottm is the} plate _width deviation between the plate rear end and the plate center

Further, the set width variation amount Δω for each pass schedule is calculated by the following formula, and the set width variation amount Δω after the final pass schedule is set to 0. Δω = ΣΔω _i / N where Δω _i : N division in the rolling direction, and the strip width deviation between each division point and the plate central portion

The set width variation amount Δω for each pass schedule is set such that the rolling direction of the rolled material is divided into N and the standard deviation of the strip width at each division point is minimized, and the standard deviation of the final pass schedule is set. It is characterized by setting to 0.

To achieve the above object, the plane shape control device for plate rolling according to the present invention has a plane shape control device for plate rolling provided with an edging roll and is arranged downstream of a horizontal rolling roll. A plate width detecting means, a measuring means for measuring the plate width based on a signal from the plate width detecting means, a calculating means for calculating the width variation amount of the plate front / rear end based on the signal from the measuring means, and a preset path. Comparison calculation means for comparing and calculating the set width variation amount for each schedule and the width variation amount;
And a control means for controlling the reduction amount of the edging roll based on the calculation result of the comparison calculation means.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic configuration of a plane shape control device for thick plate rolling according to an embodiment of the present invention, and FIG. 2 is a relation between an edging reduction amount, a width variation amount, a crop length and a yield. FIG.

In FIG. 1, 11 is a steel plate, 12 is a horizontal rolling roll, 13 and 13 'are edging rolls, 14a,
14b is a strip width detector (for example, a laser displacement meter) installed in the vicinity of the rolling mill, 15 is a strip width measuring unit, 16 is a strip profile amount calculating unit at the strip front / rear end calculated from the strip width of the entire rolling length, and 17 is an edge. This is a calculation unit for the jag gap setting value. From the measured value of the plate width of the plate width detector 14 over the entire length of the steel plate 11, the width-deformation-amount calculating unit 16 obtains the width-deformation amount of the plate front / rear end.

After each pass, the width variation amount Δω_Top ⁱ,
Δω_Bottom ⁱIs measured. Paths calculated in advance
Schedule setting calculation (recorded as data in the calculation unit 17
Memory width variation Δω_Top ^Pi, Δω_Bottom ^PcAnd measured
Width variation amount Δω_Top ⁱ, Δω _Bottom ⁱCompare with
U.

[Equation 1] From the difference δ between the actual measurement value and the calculated value, the correction amount δ _hE of the edge drag reduction amount in the next edge path is calculated by δ _hE = a ₁ · δ (2). Here, a ₁ is a parameter for adjustment.

As described above, the width variation amount after each pass is measured, the deviation amount from the set value is corrected in the next edging pass, and (Δω _Top + Δω _Bottom ) · (1/2) at the finish rolling exit side. = 0 (3) The control is performed.

FIG. 2 shows the relationship between the edging reduction ratio when rolled according to a predetermined pass schedule, the average width variation amount (a) at the trailing edge of the strip, the average crop length (b) at the trailing edge of the strip, and the yield. (C) is shown. As shown in the figure, by setting the edging reduction rate to about 14%, the average width variation amount at the platen rear end becomes 0, and the yield at that time takes about the maximum value. Therefore, by measuring the width variation amount by the plate width detector 14 without measuring the crop shape, it is possible to obtain the optimum edging reduction amount that maximizes the yield in practical use.

Further, instead of the equation (3), the equation (4) may be controlled so that the average of the plate width deviations over the entire length of the plate becomes zero, that is, the steel plate 11 becomes rectangular. If the strip width at the center of the strip in the rolling direction is ω _C , Δω _C = ω _i −ω
_C , ω _i is the plate width at the i division point, and the average value of Δω _i is Δω = ΣΔω _i / N (4) However, Δω _i is a plate width deviation between each of the dividing points and the plate central portion after N divisions in the rolling direction.

Further, according to the equation (5), the standard deviation of the plate width deviation of the entire length of the plate may be controlled to be the minimum, that is, the steel plate 11 may be rectangular. Regarding the standard deviation of the strip width, the strip width when divided into N in the rolling direction is ω ₁ ·· ω _i ··
_Let ω _N.

[Equation 2]

FIG. 3 shows an embodiment in which plate width detectors 21a and 21b for measuring the plate width before rolling are additionally provided.
By the plane shape control device shown in FIG. 3, the steel plate 1 before rolling
By actually measuring the plate width of 1 and performing the same control as described above,
The precision of setting the amount of reduction by the edger rolls 3, 3'is improved. As a result, it becomes possible to control the planar shape with high accuracy as in the embodiment shown in FIG.

[0026]

As described above in detail with the embodiments, according to the present invention, it is possible to set the optimum edging reduction amount for the planar shape control only from the actual measurement data of the plate width and measure the shape of the crop. It is possible to control the planar shape efficiently and accurately without any need to improve the yield.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a plane shape control device for plate rolling according to an embodiment of the present invention.

FIG. 2 is a graph illustrating a relationship between an edging reduction amount, a width variation amount, a crop length, and a yield.

FIG. 3 is a schematic configuration diagram of a plane shape control device for plate rolling according to another embodiment of the present invention.

FIG. 4 is a conceptual diagram showing a defective shape state in plate rolling.

FIG. 5 is an explanatory view showing a rolling condition of plate rolling.

FIG. 6 is an explanatory view showing a modification of the planar shape of the plate edge rear end.

FIG. 7 is an explanatory view showing a modification of the planar shape of the plate front end.

FIG. 8 is a line configuration diagram of thick plate rolling.

[Explanation of symbols]

 11 Steel Plate 12 Horizontal Rolling Roll 13, 13 'Edging Roll 14a, 14b, 21a, 21b Strip Width Detector 15 Strip Width Measuring Section 16 Width Variant Amount Calculating Section 17 Computing Section

Continued Front Page (72) Inventor Shuji Kaneko 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima Mitsubishi Heavy Industries Ltd. Hiroshima Works

Claims (5)

[Claims] 1. A plane shape control method in thick plate rolling, which comprises making a plate front and rear end rectangular by using an edging roll,
The strip width after rolling is measured, and the width variation amount of the strip front end is calculated from the measured value.The width variation amount is compared with the preset width variation amount for each pass schedule calculated in advance, and the comparison calculation result is obtained. A planar shape control method for thick plate rolling, characterized in that the amount of reduction of the edging roll of the next pass schedule is controlled based on the above. 2. The plane for plate rolling according to claim 1, wherein the set width variation amount Δω for each pass schedule is calculated by the following formula, and the set width variation amount Δω after the final pass schedule is set to 0. Shape control method. Δω = (Δω _Top + Δω _Bottm ) / 2 where Δω _Top is the plate _width deviation between the plate front end and the plate center Δω _{Bottm is the} plate _width deviation between the plate rear end and the plate center 3. The plane for plate rolling according to claim 1, wherein the set width variation amount Δω for each pass schedule is calculated by the following formula, and the set width variation amount Δω after the final pass schedule is set to 0. Shape control method. Δω = ΣΔω _i / N where Δω _i : N division in the rolling direction, and the strip width deviation between each division point and the plate central portion 4. The set width variation amount Δω for each pass schedule according to claim 1, wherein the rolling direction of the rolled material is divided into N parts,
A plane shape control method for thick plate rolling, characterized in that the standard deviation of the strip width at each division point is set to be the minimum, and the standard deviation of the final pass schedule is set to 0. 5. A plane shape control device for plate rolling equipped with an edging roll, wherein the plate width is measured based on a signal from the plate width detecting means arranged downstream of the horizontal rolling roll and the plate width detecting means. Measuring means, calculating means for calculating the width variation amount of the rear edge of the plate based on the signal from the measuring means, and comparison calculating means for comparing and calculating the preset width variation amount for each preset pass schedule and the width variation amount. And a control means for controlling the reduction amount of the edging roll based on the calculation result by the comparison calculation means.