JPS6021335A - Method and device for controlling heat treatment in continuous annealing - Google Patents

Abstract

PURPOSE:To detect automatically and quantitatively the sign for generation of heat buckling and to prevent the generation of the heat buckling by detecting whether a thin steel sheet under a continuous heat treatment has the heat buckling or not and controlling >=1 kind among the temp. of a heating zone, the speed of a cooling zone, the tension of the steel sheet, etc. according to the detection signal thereof. CONSTITUTION:The above-described thin steel sheet 10 is passed through a heating zone 12, a soaking zone 14, a cooling zone 16 and an overaging treatment zone 18 and is thereby subjected to prescribed heat treatments for heating, soaking and cooling. The conditions for dealing with emergency in the event of generation of heat buckling during such heat treatment and the equations for calculating the conditions necessary for suppressing such generation and restarting the normal operation are preliminarily inputted in an arithmetic device M. If the sign for generation of the heat buckling in the sheet 10 is detected, the place where the heat buckling arises and the size thereof are immediately detected according to the distance signals transmitted from distance detectors Pa-Pd. The optimum conditions meeting the same are calculated and the results thereof are made into control signals which are outputted to a temp. controller for the soaking zone, a temp. controller 32 for the soaking zone, a controller 36 for the overaging treatment zone, tension controllers for the steel sheet (40-46), etc.

Description

Detailed Description of the Invention (Technical Field) During heat treatment of cold-rolled thin copper sheets by continuous furnace annealing, buckling of the TLI sheets that often occurs during the treatment.
Regarding the method and device for preventing wrinkles, this Mei 111
The technical content described in the box is included in the field of technology to which continuous annealing of copper plates belongs, especially the appearance annealing process 1.
This paper will present the results of the development of a means for appropriately detecting signs of the heat buckle generation behavior in accordance with the generation behavior of heat buckles in section '6, and a means for controlling it1 that can immediately respond to the detected information. , Problem C) Thin molding, such as a processed flange plate for an automobile, is not suitable for molding using a press or the like.
(It is necessary to have a good compatibility, and for this reason, after 11 rounds of reimasho, annealing is applied).

For this type of annealing, the so-called box annealing method was once common, but the time required for annealing was 1111
Because the gap is so large, there are major disadvantages in terms of productivity, economy, and product regulations, and in recent years, 1. i
It is well known that the continuous annealing method has been developed and its superiority has been gradually clarified, and that the current state is shifting to the continuous annealing method.

However, at present, the continuous annealing method is not superior to the conventional box annealing method in all aspects.
There are still many issues that need to be improved.

One of them is the problem of transportability during continuous annealing of cold-rolled thin IN plates (hereinafter simply referred to as μ plates).

First of all, most continuous annealing equipment currently has a single vertical ship, in which the steel plate is transferred while being supported by upper and lower hearth rolls, and subjected to various thermal environmental conditions such as heating, soaking, and cooling. It gets roughed up.

At this time, steel plates tend to have temperature differences in the width direction, which causes deformation due to thermal stress caused by the difference in thermal expansion, and vibration of the steel plate makes the tension distribution between the hearth rolls uneven and uniform.1) As a result, meandering is likely to occur.

If this meandering occurs, normal conveyance will not occur, so in order to prevent this, the shape of the hearth roll is generally made into a medium-sized narrow body or a crown shape to give the hearth roll a self-centering effect. being done.

However, when the moisture content 41 and the non-uniformity of the tension distribution, which cause the meandering mentioned above, increase, a large amount of self-centering occurs, resulting in buckling deformation in the width direction of the steel plate 61, that is, JLT-like defects called heat buckles. occurs.

When this heat buckle occurs, the value of the product decreases,
In addition to damaging the plate, normal heat treatment 1·'h pear cannot be maintained, and sometimes serious troubles such as ω:1 (plate breakage) occur.

Also, due to the above, the thickness and width of the Wl plate,
Furthermore, there are restrictions on the maximum heating temperature, etc., which leads to the disadvantage that it becomes difficult to produce high value-added products using the continuous annealing method.

Therefore, establishing a method for preventing heat buckling during continuous annealing has become an extremely important issue from both the operational technology of continuous annealing equipment and the production technology of products.

(Prior art and its drawbacks) Regarding the above section, the current heatback detection means is, for example, by installing television cameras at several locations in the continuous annealing equipment and monitoring the images. , is considered to be the only and best method.

From a practical point of view, the most effective means of dealing with heat buckling is to detect the signs of heat buckling in its early stages and take immediate action accordingly. When using the above method, there remain problems such as delayed detection, the inability to obtain quantitative information, and the inability to perform automatic control that requires an observer, and no proposals for improvements from these viewpoints have been found.

In other words, the conventional techniques are far from being able to solve the basic problems mentioned above, and it is difficult to expect them to be effective in practical use.

(Objective of the Invention) In view of the problems of the prior art as described above, in order to advantageously solve the problems, the signs of heat buckling are automatically and quantitatively detected in the initial stage of occurrence, and the detected information is also used. The purpose of this invention is to take optimal and quick measures to deal with the situation, and it has the practical advantage that it can be put into practical use immediately at the current state of the art compared to the conventional technology, and it also has the practical advantage of being able to be put into practical use immediately at the current state of the art, as well as being able to adapt to future technological developments. It is an object of the present invention to provide a heat buckle detection device and a method for preventing heat buckle in continuous furnace annealing, which has excellent applicability and expandability, and is convenient for matching the occurrence of heat buckles even when such occurrences occur.

[Structure of the Invention] The above object is advantageously achieved by the procedure and structure that are based on the following matters.

(1) When continuously heat-treating a cold-rolled silver plate by passing it through a continuous furnace annealing furnace that includes a heating zone, a soaking zone, a cooling zone, or an overaging treatment zone in the order of processing steps,
The distance to the plate at each detector is determined by a distance detector installed at at least one position in the conveyance path of the silver plate.
By detecting the presence of heat buckling in the silver plate during the heat treatment, at least one of the heating zone temperature, soaking zone temperature, cooling zone cooling rate, steel plate conveyance speed, and steel plate tension is determined according to the detection signal. A method for controlling heat treatment in a continuous annealing furnace (C 1st invention) for controlling heat treatment in a continuous annealing furnace and preventing heat buckling in addition to controlling the heat buckling.

(2) A continuous furnace annealing device having a heating zone, a soaking zone, a cooling zone, or an overaging treatment zone, and the position in the conveyance path of the silver plate that is passed through this to be continuously heat-treated. Consisting of an excitation coil that generates an alternating magnetic flux with a constant distribution, which is placed close to the steel plate at at least one location, and a detection coil that detects the rate at which the magnetic flux from the excitation coil changes in accordance with the distance to the silver plate. , and has at least one distance detector, and according to the size of the heat buckle of fVJ 'Ik determined from the distance detected by the distance detector, heating a) 1) Temperature control device, soaking zone temperature Control device σ, cooling zone cooling power 1 juice L (at least 1 of J control bean production, 硅j & conveyance speed control device and steel plate tension flil + control fFt)
A control device for a heat tank 3311 in a continuous furnace annealing device having a control means for operating the heat tank 3311 (second invention).

It is recommended that the implementation team place the four separate detectors in the heating zone, soaking zone, and cooling zone, respectively. l 'l]'
It is possible to perform i degree of control.

ㅅ゜゛1 Inventive method ゛゛ Quickly detect the hole f15゛ in the iron and buckle and take action at 1411 W
Therefore, it is possible to reliably prevent heat buckling, and it is also possible to use the method of the second invention, number 111, which is effectively used in carrying out the method of the first invention, and it is easy to do 4. .

Taking continuous furnace annealing "f" as an example, the specific contents of the light [11J] will be explained in detail.

As shown in FIG. 1, this continuous furnace annealing device has f! l
A heating zone 2, a conditioning zone 14, and a cooling zone 16 for heat-treating all 10 of the plates 10, and a heating zone 14 and an aging zone 18, which mainly transport the plate 10 to be treated. A driving wheel 20 is provided for the purpose.

Furthermore, an atmosphere thermometer 22 for detecting the atmospheric temperature in the heating zone 12, an atmosphere thermometer 24 for detecting the atmospheric temperature in the soaking zone 14, and a steel plate]0 on the inlet side of the heating zone 12.
It has a copper plate conveyance speed detector 26 for detecting the conveyance speed of the steel plate 10, and a ρ plate conveyance speed detector 28 for detecting the conveyance speed of the steel plate 10 on the exit side of the overaging treatment zone 8. Tropical] Heating zone temperature control device 3 for controlling the temperature of 2
0, a soaking zone humidity control device 32 for controlling the temperature of the soaking zone 14, a cooling:jAI speed control device @ 34 for controlling the cooling rate of the FK4 board 10 in the cooling zone 16, and an overaging treatment zone. Overaging treatment zone wetting 19 control device '1736 for controlling the humidity of 18 and copper plate conveying speed control device 38 for controlling the conveying speed of the copper plate IO by controlling the rotational speed of the drive roll 200 and in the heating zone 12 a tension control device 40 for controlling the tension of the key analysis lO in the soaking zone 14, a tension control device 42 (for controlling the tension of the first plate 10) in the soaking zone 14, and a cooling zone 1
61 analysis in 6] Tension control device 4, 4, and overaging treatment zone for controlling the tension of 0] ρ...i in 8
A tension control device 46 for adjusting the tension S' of the plate 10 is provided.

Especially in this example, near the outlet side of heating zone 2), stand 3 &
At each predetermined position along the width of l'o,
Detect the distance to ul! from the size of the distance at each position. 1. 'l Detect the size of the heat buckle on steel plate 0. For example, a distance detector P consisting of 2 (1,'! or 8 detection coils (described later))
a, and this distance 1 [one plate near the detector Pa] for measuring the surface humidity of 0, the adjusting plate temperature i'TlTa, and a similar distance detector Pb near the entrance side of the soaking zone 14. , a steel plate thermometer Tb, and a similar heat adjustment detector P near the outlet side of the soaking zone. And steel plate thermometer T. , and a similar distance 1iII1. near the outlet side of the cooling qiV la. A detector Pd and a armor plate thermometer Td are provided.

As shown in detail in FIG. 2, the distance detectors Pa-Pd are excited by an AC excitation device yζE that generates an alternating current of, for example, 5 H2~] MHz, and a constant alternating magnetic flux α, An exciting coil C that generates β, γ, δ, and ε is interlinked with the alternating magnetic flux α, γ, or even ε, and a detection coil Cal that generates an induced voltage according to the amount of interlinked magnetic flux C5 are arranged near the plate surface at intervals in the direction of the plate width W of the U plate 10, and the induced voltage of each detection coil is measured,
A voltage measuring device Mα1M outputting to an arithmetic unit, or further M.

Connect to.

In the figure, alternating magnetic fluxes β and δ indicate invalid magnetic fluxes that do not interlink with any detection filter, h is the distance between each coil and the plate surface of the armor plate 10, μ is the magnetic permeability of the steel girder 10, and ρ is the Assuming that 1 of bond 1 plate 10 is the specific resistance, when there is 1 plate ]0 within the magnetic field range of excitation coil C, detection coils Cα, C
1 or roughly C5, an induced voltage corresponding to the above-mentioned distance, magnetic permeability μ, and electric resistivity ρ is generated.

If the induced voltages generated in the detection coil Cα and the detection coil V are Vα and ■, respectively, then the following formula % formula % (]
) (2) (3) By substituting equation (2) or (3) into equation (1) and eliminating the term μ×ρ, the distance 1h of the steel plate 10 can be calculated. be able to.

Here, the AC power frequency of excitation coil C is 5 H2~]
Preferably, the frequency is in the MHz range, and the frequency is in the I MHz range.
If z is exceeded, the N-coupling, in which the induced voltage generated in the detection coils Cα and C7 depends on the magnetic permeability μ and electric resistivity ρ of the steel plate JO, becomes excessively large, and the distance of the object to be measured! tif h
The resolution for OJ changes becomes smaller,
; This is not preferable because it deteriorates the frequency by 11'+'1 degree, and if this frequency is lower than 5H2, the responsiveness of the distance detector cannot be ensured.

As described above, the detection signals from the distance detectors Pa-Pd detect the heat buckle of the steel plate 10 in the heating 4if 12 , the soaking zone J4, the cooling zone 16, and the heat buckle of the steel plate 10 in each of the heating zone J4, the cooling zone 16, and the heating zone J4. Since it gives the signs of occurrence of
Along with the detection and output signals of 8, the signals are inputted to the arithmetic unit M as shown in FIG. Temperature control device 86 and steel plate conveyance speed control device 3
8 and the operation of the tension control devices 40 to 46 are controlled by the calculation device M.
control properly.

Therefore, if the calculation procedure described above is programmed in the arithmetic unit iM in advance, the induced voltage Vα generated in the detection coil Cα and the induced voltage Vα generated in the detection coil Cβ or C7 can be
By transmitting α or ■6 to the arithmetic device M, the distance bt- between the excitation coil C and the steel plate 10 to be processed can be measured.

As mentioned above, heat buckling is particularly likely to occur in steel sheets being passed in a continuous annealing device, for example in the heating zone 1.
2, near the entry side of the soaking zone 14, near the exit side of the soaking zone 14, and near the exit side of the cooling zone 16, respectively, in the widthwise direction of the steel plate 10. Each of the continuous piece annealing furnaces by juxtaposing the distance detectors as? No matter what time the heat buckle occurs on the V□11 plate, the sign of the heat buckle that occurs on the V (including the degree of heat buckle)
Since it is detected in a positive way, f'lJ Ii for that
This makes it easier to take countermeasures.

In other words, by using the above-mentioned distance detector, the occurrence of beat buckles can be detected without contact, and when the beat buckle is detected, the initials l'I! Mouthpiece 1! In particular, Yosu board 10
Even if the transmission bFJ ratio μ and electrical resistivity ρ change due to changes in r to α during the continuous piece annealing process, there is no difference in the plate 1 #1 direction, so it will not be affected by it. Detection of the heat buckle is not hindered.

By the way, the lead precipitation 10 includes a heating zone 12, a soaking zone 14, and a cold J3.
I? fV 16 and over-aging treatment zone] 8, predetermined heat treatments such as heating, soaking, and cooling are performed. By inputting in advance into the calculation device M a method for calculating the conditions necessary to suppress the occurrence of the above and return to smooth operation,
When a sign of heat buckling is detected on the steel plate 1o to be processed, the location and size of the heat buckling are determined by Hl according to the distance signal transmitted from the distance detectors Pa-Pd.
1'i temperature control system 3.
0, soaking zone temperature control device 32, cooling zone cooling rate control device 84, overaging treatment zone control device 36, and copper plate conveyance speed control device 88 Nara Hini g: 'i plate tension control device 40 to 46
Output to etc.

Each control device operates in response to this control signal to suppress the occurrence of heat buckling, and thus the operating conditions of the continuous piece annealing device for the entire process can be adjusted to return to normal conditions.

In this embodiment, distance detectors for detecting signs of heat buckling are installed in the heating zone, soaking zone, and cooling zone, allowing detailed detection of heat buckles. And it is possible to prevent it.

Note that the installation position and number of distance IF detectors Cj1 are not limited to the example, but by providing at least one along the route along which the 4 and 11 plates in the continuous-piece chisel furnace are conveyed. , W It is oJ's ability to detect and prevent effective heat buckling.

(Effects of the Invention) As explained above, the first invention prevents troubles caused by heat buckling during continuous piece annealing of cold rolled thin steel sheets; The apparatus can be operated automatically and stably, and the second invention can be used to implement a heat treatment control method in continuous piece annealing, contributing to increasing its initial effects.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a continuous piece annealing furnace, FIG. 2 is an explanatory diagram of a buckle detection procedure according to the present invention, and FIG. 8 is a block diagram of a control system. ]2... Heating zone ]4... Soaking zone 16... Cooling zone C... Exciting coil Cα+ Cr+
Ci...Detection coil Pa-Pd...Distance detector
30...Heating zone temperature control system 32...Soaking zone temperature control device 34...Cooling zone cooling speed control device 38...Door plate conveyance speed control device 40-46...Steel machine tension control device. Patent applicant: Kawasaki Steel Corporation

Claims (1)

[Claims] 1. A cold-rolled thin copper plate is placed in a continuous annealing furnace that includes a heating zone, a soaking zone, and a cold AI zone in the order of processing steps.
When continuously heat treating the 6111 plate, the distance to the copper plate at each detector is detected by a distance detector installed at at least one position 1i in the conveyance path of the 6111 plate. Detects the occurrence of heat buckle at 604 in the inside, and controls at least one of the heating zone temperature, soaking zone temperature, cooling zone cooling rate, steel machine conveyance speed, and copper plate tension according to the detection signal. In addition, a heat treatment control method in continuous furnace annealing characterized by preventing heat buckling. A continuous furnace annealing device having a heating zone, a soaking zone, and a cooling zone, through which the sheet is passed for continuous heat treatment1],
An excitation coil that generates an alternating magnetic flux with a constant distribution is placed in close proximity to the four cold-rolled sheets at at least one location in the conveyance path of the four cold-rolled sheets, and the magnetic flux from the excitation coil is directed to one sheet. It is equipped with at least one distance detector consisting of a detection coil that detects a rate of change corresponding to the distance, and according to the size of the heat buckle of the drawing board determined from the distance detected by the shaded distance detector. , heating zone temperature control device,
A heat treatment control device in a continuous furnace truncating device, characterized by having a control means for operating at least one of a soaking zone temperature control device, a cooling zone cooling rate control device, a steel plate conveyance speed control device, and an H plate tension control device. . & The heat treatment control device according to 2, wherein a distance detector is arranged in each of the heating zone, soaking zone, and cooling zone.