JPH06330187A - Device for controlling annealing in continuous annealing equipment - Google Patents

Abstract

PURPOSE:To uniformly anneal a steel strip in the longitudinal direction by controlling the steel strip velocity in on-line without using expensive equipment. CONSTITUTION:The tension of the steel strip 16 elongation of which is given by inlet side bridle rolls 12 and outlet side bridle rolls 14 before and after a skin pass mill or a tension leveler 10 respectively in the outlet side of continuous annealing equipment 1 is measured with a tension meter 18. The tension variation rate DELTAF is detected froom the variation of this tension and based on this DELTAF, the steel strip velocity is changed with a steel strip control unit 32 and the annealing time at each position in the longitudinal direction of the steel strip is controlled and the quality is uniformized in the longitudinal direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an annealing control device for continuous annealing equipment.

[0002]

2. Description of the Related Art Conventionally, as a method for controlling annealing in continuous annealing equipment, a plate thermometer is installed on the exit side of the annealing furnace to measure the plate temperature of a steel strip, and annealing is performed so that this plate temperature becomes a set value. Methods of controlling furnace temperature have been known.

In addition, a method of controlling the annealing temperature by detecting the state of the steel strip by measuring the crystal grain and hardness of the steel strip online using a grain size meter or a magnetic type hardness measuring device has been tried. There is.

[0004]

As described above, the purpose of controlling the annealing furnace temperature based on the plate temperature on the outlet side of the annealing furnace is to obtain a uniform material in the longitudinal direction of the steel strip. However, the state of the steel strip before annealing, such as chemical composition, rolling temperature,
Since the material is influenced by the difference in material such as rolling reduction, there is a problem in that the annealing temperature control applied to the plate thermometer does not always provide a steel strip having a uniform material in the longitudinal direction.

Further, in the case of online control using the above-mentioned crystal grain size measuring instrument or magnetic hardness measuring instrument, the equipment cost is high, and it is necessary to have a lot of data to be the standard of the material to be measured. It was difficult to put into practical use due to problems such as not being easy to maintain.

Further, when controlling the temperature of the annealing furnace, it takes time to change the temperature, so that there is a problem that the responsiveness to the temperature of the steel strip is poor.

The present invention has been made in view of the above-mentioned problems of the prior art. The equipment cost is relatively low, and there is no need to prepare data as a reference for the material to be measured, and maintenance is not required. An object of the present invention is to provide an annealing control device for continuous annealing equipment, which is easy and can be controlled online so that the material of the steel strip becomes uniform in the longitudinal direction.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to an elongation rate control device which is arranged on the outlet side of a continuous annealing equipment and which gives a constant elongation rate to a steel strip that is passing through. A tension measuring device for measuring the tension of a given steel strip, and detecting a tension change based on the measured value of this tension measuring device, and controlling the steel strip speed of the continuous annealing equipment according to the tension change amount. The above-mentioned object is achieved by an annealing control device for a continuous annealing equipment comprising a control device.

[0009]

The present invention focuses on the fact that when the steel strip to which the elongation has been applied has a change in material, this appears as a change in the tension of the steel strip. Since the change in the tension of the steel strip after being given the elongation is detected and the speed of the steel strip is controlled based on the change in the tension, the steel strip can be longitudinally moved in the longitudinal direction without expensive equipment. It can be annealed to a uniform material.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

In this embodiment, a skin pass mill or a tension leveler 1 arranged on the outlet side of a continuous annealing equipment 1.
The input side bridle 12 and the output side bridle 14 of 0 are used as components of the elongation rate control device 20,
By these inlet bridle 12 and outlet bridle 14, a skin pass mill or a tension leveler 10 is provided.
A predetermined elongation rate, that is, a speed difference is given to the steel strip 16 that passes through.

A tensiometer 18 for measuring the tension of the steel strip 16 is arranged between the entrance side bridle 12 and the skin pamill or the tension leveler 10. The tensiometer 18 is also configured as a part of the elongation control device 20.

The elongation control device 20, as shown in FIG. 1, includes a tension converter 22, a PLG 24, and a speed calculator 2.
6, an elongation rate calculator 28 and a tension change amount calculator 30 are included. Further, the signal from the elongation control device 20 is output to the steel strip speed control device 32.

The tension converter 22 converts the output signal of the tensiometer 18 into a steel strip tension F, and the speed calculator 26 calculates the feed amount L of the steel strip 16 at the position of the outlet bridle 14. The line speed V _D is calculated and output based on the signal from the PLG 24 output accordingly.

The elongation rate calculator 28 calculates and outputs a substantial elongation rate ε'of the steel strip 16 from the speed difference between the entrance side bridle 12 and the exit side bridle 14.

The tension change amount computing unit 30 receives the steel strip tension signal F from the tension transducer 22 and the speed computing unit 2.
Based on the line speed signal V _D from 6 and the set elongation rate set value ε, the actual elongation rate ε ′ from the elongation rate calculator 28, and the material correction value M input value, the tension change of the steel strip 16 The amount ΔF is calculated.

The steel strip speed control device 32 controls the steel strip speed in the continuous annealing equipment based on the signal of the tension change amount ΔF input from the tension change amount calculator 30.

For example, if the tension change amount ΔF is positive,
The hardness of the corresponding part of the steel strip 16 is too high,
On the contrary, if it is negative, it means that the corresponding portion of the steel strip 16 is insufficient in hardness, and the steel strip speed control device 32 controls the steel strip speed in the continuous annealing equipment so as to compensate for the excess or deficiency of these hardnesses. Has been

Next, the operation of the apparatus of the above embodiment will be described.

Skin pass mill or tension leveler
-The steel strip 16 passing through the
A predetermined elongation rate ε, that is, a speed difference between the bridle 14 on the outgoing side
(V _D-V_E) Is given.

The tension of the steel strip 16 between the entrance-side bridle 12 and the exit-side bridle 14 is detected by the tensiometer 18, and this signal is converted into the tension signal F by the tension converter 22 to change the tension. It is input to the calculator 30. On the other hand, the speed calculator 26 calculates the line speed V _D of the steel strip 16 based on the signal from the PLG 24 corresponding to the feed amount of the steel strip 16 in the exit side bridle 14, and this is calculated by the elongation rate calculator 28 and the tension. Output to the change amount calculator 30.

The elongation rate calculator 28 calculates an elongation rate ε'substantially given to the steel strip 16 based on the input line velocity V _D signal and outputs it to the tension change amount calculator 30.

The tension change amount calculator 30 receives the input tension signal F, line speed V _D , material correction value M, and set elongation ε.
Then, the tension change amount ΔF is calculated from the actual elongation rate ε ', and this signal is output to the steel strip speed control device 32.

Here, the reason why the actual elongation rate ε'is detected and input to the tension change amount computing unit 30 is that when the line speed V _D is changed, the change in the strain rate of the steel strip 16 affects the steel strip output F. Changes, so that the tension change amount ΔF can be accurately detected by correcting the speed and making it the same as in the constant speed state. Here, since the strain rate further changes depending on the material of the steel strip, the correction value M is added to calculate the tension change amount ΔF more accurately.

When the steel strip was annealed by using the elongation control device 20 and the steel strip speed control device 32, the responsiveness was very good and the material in the longitudinal direction of the product steel strip could be made uniform. That is, when controlling with the plate temperature, it is necessary to change the furnace temperature of the annealing furnace having a large heat capacity in order to change the plate temperature, so it takes time, but the change of the steel strip speed is quick. By changing the steel strip speed, that is, the annealing time, the material could be controlled with good responsiveness.

In this embodiment, the material in the longitudinal direction of the steel strip after continuous annealing can be made uniform on-line without the need for expensive equipment.

By recording the input signal of the tension change amount calculator 34 and the tension change amount signal ΔF without performing the annealing temperature control, the abnormal portion can be determined and the abnormal portion is cut off. As a result, it is possible to eliminate the abnormal portion from being mixed in the product. Furthermore, by preparing data that serves as a reference for the material to be measured, it is possible to evaluate the hardness, tensile strength, etc. based on the steel strip tension.

In the above embodiment, the skin pass mill or the tensilverer after the continuous annealing equipment is provided with the inlet side bridle 12 and the outlet side bridle 14, and the elongation rate is controlled by the present invention. However, if a continuous path equipment such as a skin pass mill or a tension leveler is installed in-line as a shape correction device in the continuous annealing equipment, these can be replaced with an elongation control device and used to reduce the equipment cost. It can be reduced.

Further, if the speed of the steel strip is lowered in order to change the annealing speed, it becomes a factor of lowering the efficiency and hence the productivity. Therefore, in this case, control of the annealing temperature should be combined with speed control. May be.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an annealing control device for continuous annealing equipment according to the present invention.

[Explanation of symbols]

 1 ... Continuous annealing equipment 10 ... Skin pass mill or tension leveler 12 ... Incoming bridle 14 ... Outgoing bridle 16 ... Steel strip 18 ... Tensometer 20 ... Extension control device 22 ... Tension transducer 24 ... PLG 26 ... Speed calculator 28 ... Elongation rate calculator 30 ... Tension change amount calculator 32 ... Steel strip speed control device

Claims (1)

[Claims] Claim: What is claimed is: 1. An elongation rate control device, which is arranged on the outlet side of a continuous annealing facility and gives a constant elongation rate to a passing steel strip, and a tension of the steel strip to which the elongation rate is given by the elongation rate control device. A tension measuring device for measuring, and a controller for detecting a change in tension based on a measured value of the tension measuring device and controlling a steel strip speed of the continuous annealing equipment according to the amount of change in tension. An annealing control device for continuous annealing equipment.