JPH08209253A - Method for controlling shape of metallic strip - Google Patents

Abstract

PURPOSE: To obtain a final product shape even if the follow-up of the shape control capacity of a temper rolling mill is not possible by detecting the shape of a strip on the outlet side of this temper rolling mill and controlling the temp. in the transverse direction of the strip in a continuous annealing furnace in accordance therewith. CONSTITUTION: The shape of the steel strip S emitted from the temper rolling mill 1 is measured by a shape detector 10 and the data thereof is recognized by a shape recognizing device 11. Whether or not the shape control capacity of the temper rolling mill 1 is approximate to the threshold is decided by a shape control capacity deciding device 14 by using the recognized actual shape of the steel strip 1, the target shape from a target shape setting device 16 and the control output quantity from a shape controller 13 to a roll bender 12. The range of the inlet side shape of the temper rolling mill 1 by which the outlet side shape of the temper rolling mill is controllable to the target value is calculated by an inlet side optimum shape determining device 15 from the result of the decision. The cooling pattern control in the transverse direction of the steel strip S in one, for example, primary cooling zone 5, of the heating zones of the continuous annealing furnace 3 is executed in order to realize the calculated inlet side optimum shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous processing line for a metal strip such as a thin steel strip (which will be described below as an example of a steel strip), which comprises a continuous annealing furnace followed by a temper rolling mill. The present invention relates to a shape control method for a metal strip, the shape of which is controlled by a temper rolling mill.

[0002]

2. Description of the Related Art In the cooling zone of continuous heat treatment equipment such as a continuous annealing furnace for performing heat treatment such as heating, soaking, and cooling on a steel strip,
Cooling temperature control in the plate width direction is usually performed. As one example thereof, a gas jet type cooling device described in JP-A-60-169524 is shown in FIGS. 2 and 3. FIG. 2 is a block diagram of the cooling device, S is a steel strip, 51 is a gas jet device,
52 is a roll, 54 is a control arithmetic unit, 55 is a plate thermometer,
The steel strip S is conveyed while being successively wound around a plurality of rolls 52, and is cooled at its contact surface.

FIG. 3 is a perspective view of the gas jet device 51.
Is a flow control valve and 57 is a gas supply pipe. The chamber 53 of the gas jet device 51 is divided into a plurality in the width direction,
A gas supply pipe 57 is connected to each chamber via a flow control valve 56, and the temperature distribution in the plate width direction is measured by a plate thermometer 55, and the temperature difference from the average temperature in the plate width direction exceeds an allowable value. Only in this case, the corresponding flow control valve 56 is opened by a command from the control arithmetic unit 54 to eject the cooling gas.

The purpose of such a conventional technique is to provide good plateability in the heat treatment equipment and to make the plate surface shape flat on the exit side of the heat treatment equipment. The main focus was on homogenization. That is, the target shape of the steel strip after cooling is the shape on the outlet side of the heat treatment furnace, and the final product shape after temper rolling was not considered.

By the way, in such a continuous heat treatment equipment, even if the product shape is good on the outlet side of the continuous heat treatment equipment, as the range of the target material such as material size and material such as plate thickness and width is expanded. Even if the steel strip is temper-rolled by the temper rolling mill installed on the outlet side of the continuous heat treatment equipment, the final product shape is not always good, and the shape control capability of the temper rolling mill can follow. However, there are some cases in which a defective shape occurs.

In order to ensure the shape control ability of the temper rolling mill, it is necessary to make a large capital investment such as expanding the pressure range for roll bending and changing the type of rolling mill. Although it can be dealt with by changing the initial crown given to the work roll of the temper rolling mill,
Since it is necessary to prepare a work roll having a different crown for each target material, the operating cost of the roll increases, which is not preferable.

That is, in the present situation, the shape control is independently performed in a series of manufacturing processes of heat treatment and temper rolling. If the shape control capability of the temper rolling mill is sufficient, there is a particular problem. However, if not, it is necessary to further correct the shape through another process such as tension leveler, and improvement has been desired.

[0008]

The present invention solves such problems and realizes a shape control method capable of obtaining a good final product shape even when the shape control capability of the temper rolling mill cannot follow. The purpose is to

[0009]

The present invention according to claim 1 is a method of controlling the shape of a metal strip in a continuous processing line of a metal strip, which comprises a continuous annealing furnace and a temper rolling mill. Then, the shape of the metal strip is detected on the exit side of the temper rolling mill, and if it is determined that the shape control capability of this temper rolling mill is exceeded, temperature control in the strip width direction is performed in the continuous annealing furnace. This is a method for controlling the shape of a metal strip, characterized in that the shape of the metal strip supplied to the temper rolling mill is corrected in advance by performing the above-mentioned operation.

The present invention according to claim 2 is a method for controlling the shape of a metal strip in a continuous processing line for metal strips, which comprises a continuous annealing furnace and a temper rolling mill installed next to the metal strip. When it is expected that the shape control capacity of the temper rolling mill will be exceeded from the operation data depending on the dimensions and materials, it is supplied to the temper rolling mill by controlling the temperature in the strip width direction in the continuous annealing furnace. A shape control method for a metal strip, characterized in that the shape of the metal strip is modified in advance.

[0011]

[Operation] In the present invention, whether or not the temper rolling mill is within the control capability limit is determined from the plate shape on the exit side of the temper rolling mill and the control command amount to the shape control actuator such as a roll bender. If it is judged and it is close to the control capacity limit,
Plate shape on the temper rolling mill entrance side, that is, by pre-controlling in a direction to help control in the temper rolling mill within the allowable range of plateability in the plate shape on the exit side of the annealing furnace which is the previous step, It is intended to control the plate shape on the outlet side of the temper rolling mill to a target level.

[0012] For example, when it is determined that the selvage elongation tendency remains on the temper rolling mill exit side, the target shape on the annealing furnace exit side is set to be a belly stretch tendency, and the temper rolling mill exit side has a belly stretch tendency. If it is judged that the remaining shape remains, the target shape on the outlet side of the annealing furnace is set to the ear extension tendency.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the equipment configuration of an embodiment of the present invention. S is a steel strip, 1 is a temper rolling mill, 2 is a looper, 3 is a continuous annealing furnace, 4 is its secondary cooling zone, 5 is a primary cooling zone, 6 is a heating soaking zone, 10 is a shape detector, 11 Is a shape recognition device, 12 is a roll bender, 13 is a shape control device, 14 is a shape control capability determination device, 15 is an input side optimum shape determination device, 16 is a target shape setting device, 17 is an input side optimum shape storage device, 18 Is a tracking device, 20 is a cooling device provided in the primary cooling zone, 21 is a scanning plate thermometer, 22 is a plate temperature profile determination device, 23 is a plate width direction cooling pattern control device, and 24 is an optimum plate temperature. The pattern determination device 25 is a target plate temperature constraint condition setting device.

The steel strip S extends from the right side to the left side in the figure, and the heating and soaking zone 6 of the continuous annealing furnace 3 is the primary cooling zone 5 and the secondary cooling zone 4 is
After passing through, it reaches the temper rolling mill 1 via the looper 2 and its shape is corrected. Steel strip S temper-rolled by temper rolling mill 1
The shape is measured by a shape detector 10 using a tension distribution measuring device using a split roll, a laser range finder, or the like, and the data is recognized by the shape recognizing device 11. In the shape recognition device 11, for example, the shape distribution in the plate width direction is approximated by a quartic function or an orthogonal function, and the value of the function at a predetermined position in the plate width direction is used as the shape, and the value and the target shape setting are set. The shape control device 13 so that the difference from the target shape set by the device 16 becomes zero.
The control output to the roll bender 12, which is a shape control actuator, is determined from this, and on the basis of this, the shape feedback control in the temper rolling mill 1 is performed.

The shape control in the conventional temper rolling mill is performed only by the above-described structure, but the present invention has the following functions in addition to this. The actual shape of the steel strip S after temper rolling recognized by the shape recognition device 11, the target shape set by the target shape setting device 16, and the control output amount from the shape control device 13 to the roll bender 12 are used. The shape control capability determination device 14 determines whether the shape control capability of the temper rolling mill 1 is close to the limit.

According to this determination method, for example, the bending force in the roll bender 12 is close to the upper limit even though the ear extension tendency is large with respect to the target shape, or conversely, the bending force is the lower limit when the belly extension tendency is large. If it is close to, the shape control capability is determined to be near the limit. From this determination result, the optimum inlet shape determining apparatus 15 calculates in what range the inlet shape of the temper rolling mill 1 can control the outlet shape of the temper rolling mill 1 to a target value. Roll vendor 12 for example
Based on the coefficient of influence of the shape on the input side and the coefficient of influence of the input side shape on the output side shape, the output side shape is as the target and the roll bender 12 which is the shape control actuator is located near the center of the operating range. Calculate the side optimal shape.

Next, in order to realize the entry-side optimum shape calculated here, in one of the heat treatment zones of the continuous annealing furnace 3, for example, the primary cooling zone 5, the cooling pattern control of the steel strip S in the plate width direction is performed. I do. First, based on the target shape determined by the entrance-side optimum shape determining device 15, the optimum plate temperature pattern determining device 24 determines the target value of the plate temperature distribution in the plate width direction on the cooling zone outlet side, which is determined in the plate width direction. Input to the cooling pattern control device 23. In the plate width direction cooling pattern control device 23, within the plate temperature pattern conditions set by this target plate temperature pattern and the target plate temperature constraint condition setting device 25, the plate temperature is obtained from the temperature signal obtained from the scanning plate thermometer 21. A cooling pattern control command is output to the plate width direction cooling pattern control device 23 based on the difference from the actual plate temperature profile value produced by the profile determination device 22. The plate width direction cooling pattern control device 23 changes the cooling capacity in the plate width direction based on this command to realize a desired plate temperature distribution.

As a means for changing the cooling capacity in the plate width direction, the gas jet type cooling device shown in FIG. 3 can be used. Here, the target plate temperature constraint condition setting device 25
Is for determining the constraint of the plate temperature pattern that does not impair the stripability of the line after the cooling zone, depending on the material conditions such as the plate width, plate thickness and steel type of the target steel strip S. You may leave it.

In the above description, the steel strips existing between the temper rolling mill and the annealing furnace have the same plate thickness, plate width, material, etc. However, in the actual continuous annealing equipment, Since there may be a plurality of steel strips having different plate thicknesses, plate widths, materials, etc. between the rolling mill and the annealing furnace, the tracking device 18 is necessary in this case. The connection part of the steel strip charged from the entry side of the line is tracked by the roll rotation speed signal, etc. to track where the connection part is currently located in the line, and the thickness and width of each steel strip. , The target shape setting device 1 while always holding information necessary for operation such as material
6, output to the optimum plate temperature pattern determination device 24, the target plate temperature constraint condition setting device 25, etc. at any time.

On the other hand, the entrance-side optimum shape memory device 17 is a memory having a learning function. Optimum entry side shape determined from the result of temper rolling for each factor affecting shape such as strip thickness, strip width, steel type for each strip, and data of target strip temperature pattern in the cooling zone of the strip Memorize and learn the data from the tracking device 18 such as the thickness, width and steel type of the steel strip that passes through the cooling zone as a key, and enter the data from the past steel strip data of the same type in the memory. The optimum shape set value is determined and input to the optimum plate temperature pattern determination device 24 through the entrance side optimum shape determination device 15 to control the cooling pattern in the width direction of the annealing furnace.

[0021]

According to the present invention, the final shape of the steel strip on the delivery side of the rolling mill can be made good even when the shape control capability of the temper rolling mill is exceeded. It is possible to avoid re-processing due to, and to improve quality and productivity, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a device configuration of an embodiment of the present invention.

FIG. 2 is a configuration diagram of a cooling device showing a conventional technique.

FIG. 3 is a perspective view showing a part of FIG.

[Explanation of symbols]

 1 Temper rolling mill 2 Looper 3 Continuous annealing furnace 4 Secondary cooling zone 5 Primary cooling zone 6 Heating soaking zone 10 Shape detector 11 Shape recognition device 12 Roll bender 13 Shape control device 14 Shape control capacity determination device 15 Optimal entry side Shape determining device 16 Target shape setting device 17 Optimal input side shape memory device 18 Tracking device 20 Cooling device 21 Scanning plate thermometer 22 Plate temperature profile determination device 23 Plate width direction cooling pattern control device 24 Optimal plate temperature pattern determining device 25 Target Plate temperature constraint condition setting device 51 Gas jet device 52 Roll 53 Chamber 54 Control calculation device 55 Plate thermometer 56 Flow control valve 57 Gas supply pipe S Steel strip

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Claims (2)

[Claims] 1. A method for controlling the shape of a metal strip in a continuous metal strip processing line comprising a continuous annealing furnace followed by a temper rolling machine, wherein the shape of the metal strip is at the exit side of the temper rolling machine. Is detected, and when it is determined that the shape control capability of this temper rolling mill is exceeded, by performing temperature control in the strip width direction in the continuous annealing furnace, the metal strip supplied to the temper rolling mill is controlled. A shape control method for a metal strip, characterized in that the shape is corrected in advance. 2. A method for controlling the shape of a metal strip in a continuous processing line for metal strips, comprising a continuous annealing furnace and a temper rolling mill, which is adjusted from operating data according to the size and material of the metal strip. When it is expected that the shape control capability of the temper rolling mill will be exceeded, the shape of the metal strip supplied to the temper rolling mill can be modified in advance by controlling the temperature in the strip width direction in the continuous annealing furnace. A characteristic method for controlling the shape of a metal strip.