JP3930847B2 - Thick plate rolling method - Google Patents

Description

  The present invention has a mechanism in which at least one of the upper and lower roll assemblies supports a work roll by a divided backup roll divided into three or more in the axial direction, and each of the divided backup rolls has a load detecting device, In a plate rolling mill equipped with a reduction mechanism and a reduction position detection device, a warm thick plate material having a temperature distribution in the plate width direction or a thick plate material having no temperature distribution in the control cooled plate width direction or a controlled cooled plate width The present invention relates to a rolling method for correcting a thick plate material having a temperature distribution in the direction.

In recent years, quality requirements of steel materials called thick steel plates are becoming stricter, and various rolling and straightening techniques have been developed to meet these requirements. In general, the above-described thick steel plate is a steel plate rolling facility, that is, a plate rolling mill, and the finished rolled plate is subjected to finishing processes such as shearing, heat treatment, shape correction, and painting through a cooling device and / or a cooling floor. The product is shipped to the factory.
When a manufacturer performs secondary processing, a product that does not have the undulation or bending when the product is cut to a predetermined dimension is desired. In order to guarantee flatness at the time of product shipment, it has been dealt with by correcting with a leveler or a press. However, a plate rolling machine that detects the load distribution for each of the divided backup rolls divided into three or more divisions, estimates the load distribution between the rolled material and the work roll, and controls the plate shape based on the estimated load distribution (For example, refer to Patent Document 1 or Patent Document 2) discloses a method of correcting a thick plate material (for example, refer to Patent Document 3). In this plate rolling machine, it is not necessary in principle to measure and feed back the plate shape on the delivery side of the rolling mill, and therefore the plate shape can be directly controlled without time delay. According to this plate rolling machine, good plate quality, that is, good plate profile and flatness can be obtained. Hereinafter, such a plate rolling machine is referred to as an intelligent plate rolling machine.

In other words, this intelligent plate rolling machine is divided into three or more divided backup rolls, each of which is divided into three or more divided load distributions between the rolled material and the work roll during rolling, which is closely related to the shape of the rolled material. If there is a temperature distribution in the thick plate material to be corrected at the time of correction, the plate thickness will be Flatness deteriorates when thin and wide, and flatness does not deteriorate when the plate thickness is thick, but the stress remaining on the thick plate material increases, and the flatness is good and the product is cut to a predetermined size. It was not possible to stably produce a thick plate material that is a product without undulation or bending.
In general, in the case of a thin strip having a thickness of less than 5 mm, the flatness appears in a plate shape according to the stress remaining after rolling. For example, a shape detector is provided on the delivery side of the rolling mill to provide a plate shape after rolling and rolling. Measure the plate temperature distribution immediately after correction with a temperature detector provided on the machine exit side, and control the shape control end of the rolling mill (work roll bender, intermediate roll bender, intermediate roll) so as to eliminate the effects of thermal shrinkage after cooling Shift, work roll cross angle, etc.) can be mentioned, but in the case of thick plate material, the flatness hardly appears in the plate shape according to the stress remaining after rolling (correction), so the above-mentioned existing The technology could not be applied. For this reason, it has been common knowledge that with a thick plate material, the material to be corrected is corrected after cooling to room temperature. However, in recent years, there is an increasing demand to correct warm thick plate materials up to about 400 ° C. with an intelligent plate rolling machine with the aim of improving productivity and shortening the delivery time of products.

On the other hand, in this intelligent plate rolling machine, the plate shape at the time of correction requires deformation resistance when estimating the load distribution between the rolled material and the work roll, and when there is a distribution of deformation resistance in the plate width direction, There is a problem that the plate shape accuracy estimated if it is not taken into account accurately deteriorates. In general thick plate materials, even though the distribution of the deformation resistance in the plate width direction is small, there is no problem in the shape estimation accuracy. However, in the thick plate material (hereinafter referred to as CLC material) that has undergone controlled cooling, Further, there is a problem that due to uneven cooling, there is a distribution of deformation resistance in the width direction of the thick plate material to be corrected after cooling, and the shape controllability in the intelligent plate rolling machine is deteriorated.
JP-A-5-48375 JP-A-5-69010 JP 2002-66603 A

The present invention meets the above-described needs, and at least one of the upper and lower roll assemblies has a mechanism for supporting a work roll by a divided backup roll divided into three or more in the axial direction, and each divided backup. This is a plate rolling machine equipped with a load detection device, a reduction mechanism and a reduction position detection device independently on each roll, and the temperature distribution in the plate width direction with a plate thickness of 5 mm or more and a plate surface temperature of 400 ° C. or less as the material to be corrected When straightening ordinary warm planks with a certain level, even after the material to be straightened is cooled to room temperature, a plank with good flatness and no waviness or bending when the product is cut to the specified dimensions is used. A rolling method for stable production is provided.
In addition, the present invention provides an intelligent plate rolling machine with a high profile so as to obtain a target plate shape when correcting a CLC material having a temperature distribution in the plate width direction or no temperature distribution in the plate width direction. A rolling method that enables shape control with high accuracy is provided.

According to a first aspect of the present invention, at least one of the upper and lower roll assemblies has a mechanism for supporting a work roll by a divided backup roll divided into three or more in the axial direction, and each of the divided backup rolls is independently provided. load detection device, pressure mechanism and in pressing position detecting device and the provided plate rolling mill, the plate thickness 5mm and plate surface temperature with a temperature distribution in the plate width direction of 400 ° C. or less thickness 5mm or more is to be straightened material When correcting the warm thick plate material having a plate surface temperature of 400 ° C. or lower as described above , at least a temperature detector installed on the inlet side of the plate rolling machine detects the temperature in the plate width direction of the warm thick plate material, The obtained temperature signal is averaged, and the temperature of the warm thick plate material just below the center of the trunk length of the center divided backup roll and the temperature of the warm thick plate material just below the center of the trunk length of each divided width backup roll. Seeking deviation, so that the thermal expansion amount based on the obtained temperature deviation is to eliminate the influence of the plate-shaped straightening material after cooling, by adjusting the displacement of each divided backup rolls of the plate rolling mill shape And a method of rolling a thick plate material characterized by controlling residual stress ,
According to a second aspect of the present invention, in the method for rolling a thick plate material according to the first aspect, the warm thick plate material immediately below the center of the body length of each divided backup roll is obtained based on the obtained averaged temperature signal. the deformation resistance was estimated by calculating the shape immediately below the divided backup rolls of the plate rolling mill, of the plate rolling mill each split backup rolls as obtained plate-shape becomes the target value set in advance displacement Is a thick plate rolling method characterized by controlling the shape and residual stress .
Further, claim 3 of the present invention is intended for CLC material, and has at least a finishing rolling mill and a cooling device for a thick plate rolled by the finishing rolling mill, and after controlled cooling by the cooling device , At least one of the upper and lower roll assemblies has a mechanism for supporting the work roll by a divided backup roll divided into three or more in the axial direction. Each of the divided backup rolls has an independent load detection device, When straightening a thick plate with no temperature distribution in the plate width direction of 5 mm or more, which is a material to be straightened, by a thick steel plate rolling facility provided with a plate rolling machine provided with a device and a roll position detection device , when said at cooler outlet side was a difference of more than 20 ° C. in plate width direction the temperature of the plate width direction upon detection of the correct material, resulting plate rolling mill at the time of straightening the temperature The deformation resistance of the material to be straightened directly under each divided backup roll is calculated, the plate shape at the time of correction of the plate rolling machine is estimated using the deformation resistance, and this plate shape matches the target plate shape designated in advance. It is a rolling method of thick plate material characterized by controlling the plate shape and residual stress to ,
Claim 4 is the method of claim 3, when correcting the thick plate with a temperature distribution in the plate width direction of the above plate thickness 5mm is to be straightened material, the temperature detector installed in at least a plate entry side of the rolling mill The temperature in the plate width direction of the warm thick plate material is detected at, the obtained temperature signal is averaged, and the temperature of the warm thick plate material just below the center of the trunk length of the center divided backup roll and the width of each divided width backup roll Rolling to obtain the deviation from the temperature of the warm thick plate just below the center of the trunk length, and to eliminate the influence of the thermal expansion amount on the plate shape of the straightened material after cooling based on the obtained temperature deviation Adjusting the displacement of each split backup roll of the machine to control the shape and residual stress ,
Further, according to claim 5, in the method of claim 4, the deformation resistance is calculated by using the detected temperature of the correction material on the outlet side of the cooling device and the detected temperature of the correction material on the inlet side of the sheet rolling mill. It is a rolling method of the thick plate material.

  In the prior art, warm rolling of a thick plate material could not be corrected, but according to the present invention, it is possible to stably produce a product which does not generate warpage even after warm correction and good flatness after cooling and after cutting. In addition, it has become possible to stably produce a product that does not warp even after CLC material having a good flatness and slitting similarly for CLC materials that could not be corrected with high accuracy.

  FIG. 1 is a configuration diagram showing an example of a rolling mill when the present invention is applied to a warm thick plate material. In this example, the intelligent plate rolling machine is a symmetrical 6-high rolling mill, and upper and lower inner housings 4, 4 ′ are supported in the mill housing 5 so as to be movable up and down. The upper work roll 1 is supported on the upper inner housing 4 via the upper work roll chock 3 so as to be displaceable in the vertical and horizontal directions. The lower work roll 1 'is supported by the lower inner housing 4' via the lower work roll chock 3 'so as to be displaceable in the vertical direction. In addition, as shown in FIG. 2, the upper entrance side divided backup roll 2a composed of 8 sets of divided backup rolls and the upper exit side divided backup roll 2b composed of 9 sets of divided backup rolls (total of 17 sets) are respectively connected to the upper inner. It is attached to the housing 4 independently. Although not shown, each of the upper / outside divided backup rolls 2a and 2b is individually provided with a reduction device, a load detection device, and a reduction position detection device. A lower input side divided backup roll 2a 'consisting of 8 sets of divided backup rolls and a lower outgoing side divided backup roll 2b' consisting of 9 sets of divided backup rolls (17 sets in total) are respectively independent of the lower inner housing 4 '. It is attached. Although not shown, each of the lower entry / exit-side divided backup rolls 2a ′ and 2b ′ is also provided with a reduction device, a load detection device, and a reduction position detection device.

The upper inner housing 4 is moved up and down by the pass line adjusting device 6 to adjust the pass position of the material S to be corrected. A lowering force is applied to the lower inner housing 4 ′ by the hydraulic pressure reducing device 7. The upper and lower work rolls 1, 1 ′ have the same roll diameter, and although not shown, a spindle is connected to these upper and lower work rolls to transmit torque during rolling, and an electric motor and a speed reducer The upper and lower work rolls are rotated through the machine.
Table rollers 8 and 9 for conveying materials along the pass line are installed on the entrance and exit sides of the intelligent plate rolling machine. Although not shown, a work roll bending device is provided between the upper and lower work rolls 1, 1 '.

A plate temperature detector 10 is installed on the entry side of the intelligent plate rolling machine to detect the temperature in the plate width direction. This plate thermometer is of the infrared type, and by scanning in the plate width direction, the temperature (T _i ) in the plate width direction is detected, for example, at a pitch of about 10 mm and a full width of 500 msec. Since the obtained temperature in the plate width direction may include an abnormal value, an averaging process is performed in the plate width direction (average is performed immediately below each divided backup roll width. Data is ignored), and the average plate temperature (T _i ′: i = 1 to 17) immediately below the width of each divided backup roll is calculated, and the warm thickness just below the center of the trunk length of the divided backup roll located at the center A deviation (ΔT _i = T _i ′ −T ₉ ′) between the temperature (T ₉ ′) of the plate material and the temperature (T _i ′) of the warm thick plate material immediately below the center of the body length of each divided width backup roll is obtained.
When the coefficient of linear expansion of the thick plate material is α, the difference in elongation between each divided backup roll and the center of the plate when it is cooled to room temperature is expressed by ΔL _i = α · ΔT _i per unit length. When the Young's modulus of the thick plate material is E, a stress difference (Δσ _i : i = 1 to 17) between the center of the plate immediately below each divided backup roll is E · ΔL _i .
Therefore, in order to prevent a stress difference from the center of the plate after cooling, this stress difference is added to the product target plate shape from the plate shape directly under each split backup roll immediately after the correction of the thick plate material during warm rolling. The shape is controlled as the shape control target value at the time of correction. Since it takes a transfer time to the temperature detector and the straightening machine, it is preferable to perform tracking. The plate temperature detector is desirably installed not only on the entrance side of the intelligent plate rolling machine but also on the exit side, and more accurate shape control is possible using both temperature signals.

The above rolling method is effective when the temperature distribution is relatively small or when there is little influence on the deformation resistance even if there is a temperature distribution, but if not, the shape is estimated by an intelligent plate rolling mill during correction. Since accuracy deteriorates, it is necessary to change the deformation resistance immediately below the center of each divided backup roll body length according to the plate temperature at the time of shape estimation.
A tensile test piece is prepared from a thick plate material to be corrected in advance, and the effect of temperature on 0.2% proof stress is experimentally investigated by changing the ambient temperature in the temperature range from room temperature to 400 ° C, for example, by the rolling tensile test method. A relational expression k = k (ε, T) is created from the temperature T and the strain ε exerted on the resistance k. From the obtained relational expression, the load control between the plate and the work roll is estimated by an intelligent plate rolling machine to perform shape control. At that time, JP-A-6-262228, which has already been filed by the following inventors, has been applied. The shape is controlled by using the method disclosed in the Japanese Patent Publication.

That is, the load acting on the i-th divided backup roll is q _i , the load between the rolled material and the work roll corresponding to the position is p _i , the deformation matrix of the work roll axis deflection is K ^W _ij , and the divided backup roll system Assuming that the deformation matrix is K ^B _ij , the work roll profile expressed in the form of roll crown is C ^W _i , the divided backup roll profile is C ^B _i , and the work roll axial deflection is y ^W _i , the divided backup roll and work roll Equation (1) is obtained from the matching conditions.
y ^W _i = K ^B _ij q _j + C ^B _i + C ^W _i (1)
In addition, in the mathematical expression of this specification, when there is repetition of the subscript, it is expressed using Einstein's sum rules. K ^B _ij is an influence coefficient matrix representing the displacement of the i-th divided backup roll when a unit load is applied to the j-th divided backup roll. Here, the deformation of the housing and the work roll to the divided backup roll It represents a deformation matrix including flat deformation of both rolls due to contact. K ^B _ij , K ^W _ij , and y ^W _i all extract only the relative position from the mill center.

On the other hand, the work roll deflection is expressed by Expression (2) using the deformation matrix K ^W _ij and the rolling load distribution p _i acting between the rolled material and the work roll.
_{^{y W i = K W ij (}} p j -q j) (2)
Equation (1), the rolling load distribution _{p i} and erasing ^y _{W i} from the equation (2) is obtained according to equation (3).
_{^{p i = q i + [K}} W] -1 ij (K B jk q k + C B j + C W j) (3)
On the right side of Equation (3), [K ^W ] ⁻¹ _ij is a component of the inverse matrix of K ^W _ij and can be calculated in advance together with K ^B _ij . Further, since C ^B _j and C ^W _j are also quantities that can be measured or estimated, if the measured value of q _k is obtained by the rolling mill of the present invention, the rolling load distribution between the rolled material and the work rolls can be calculated by the equation (3). p _i can be calculated immediately.

Incidentally, the rolling load p _i is generally thickness at entrance side H, delivery side thickness h, deformation resistance k, friction coefficient mu, the average entry side tension sigma _b, the average exit side tension sigma _f, elongation strain difference representing the shape of a flat plate It is a function of Δε and is given by equation (4).
p _i = p _i (H, h, k, μ, σ _b , σ _f , Δε) (4)
This is expressed as follows from the relational expression k = k (ε, T).
p _i = p _i (H, h, k (ε, T _i ′), σb, σf, Δε) (5)
Here, μ in the roll bite is almost constant in the plate width direction and can be obtained by calculation and experiment. Deformation resistance k (ε, T _i ′), inlet side plate thickness H, outlet side plate thickness h, and average inlet side by _{entering: (i = 1,17 T i '} ) and the desired and the rolling conditions tension sigma _b the mean exit side tension sigma _f above average plate temperature immediately below the divided backup roll width calculated by the method of Given.
Therefore, the equation (5), by substituting elongation strain difference Δε a target, rolling load p _i for the desired shape is obtained is obtained. In order to eliminate the influence of the thermal expansion amount of the material to be straightened on the plate shape of the straightened material after cooling, the target elongation strain difference Δε is corrected and the rolling load _pi is obtained from the equation (5). , by substituting the rolling load p _i in formula (3), the load q _i of each divided backup roll for the desired shape is obtained is obtained. Therefore, the displacement of each divided backup roll is adjusted while observing the load of each divided backup roll so that the load of each divided backup roll matches q _i .

Next, the case where the present invention is applied to the correction of the CLC material will be described.
Although CLC material is often corrected with a general temperature distribution correction or plate width direction after being cooled down to room temperature is small state, in some cases, needs to be corrected also C LC material with a temperature distribution in the plate width direction . Therefore, a case where there is a temperature distribution and a case where there is no temperature distribution will be described.
First, the case where there is no temperature distribution in the plate width direction or the temperature distribution is small will be described.
3, finishing mill 11, in many cases usually a 4-high rolling mill of the mechanism for supporting the pair of work rolls in a pair of backup rolls are used, 2-high rolling mill or six-stage or more multi-high rolling mill It may be. The cooling device 12 is located on the downstream side of the finish rolling mill 11, and cools the thick steel plate after the rolling is finished to a predetermined temperature. The cooling device 12 is generally a facility that uses water as a refrigerant, but may use other refrigerants. In the cooling device 12, the thick plate rolled by the finish rolling mill 11 is controlled and cooled to produce a material called CLC material. A thermometer 14 for detecting a temperature distribution in the plate width direction after cooling of the material to be corrected cooled to a plate surface temperature of about 600 ° C. is disposed on the downstream side of the cooling device 12. Although not shown, a cooling bed is disposed downstream of the cooling device 12, and the CLC material is cooled to room temperature. A device such as a roller leveler may be provided between the finishing mill 11 and the cooling device 12. An intelligent plate rolling machine 16 is disposed downstream of the cooling device 12. This intelligent plate rolling machine 16 performs rolling with a reduction ratio smaller than that of the finish rolling mill 11, and is basically the same as the structure shown in FIG. Between the cooling device 12 and the intelligent plate rolling mill 16, there is a light rolling mill front pinch roll 15. In the figure, a pinch roll having an upper roll having a diameter larger than that of the upper work roll of the intelligent plate rolling mill 16 is shown as the front pinch roll 15 of the light rolling mill, but the vertical position of the rolled sheet is constrained. Anything is fine. Therefore, a small-diameter roll that is not driven may be used, but it is more preferable to have a structure that can apply tension. Furthermore, it is preferable to provide an upper surface guide between the light rolling mill front pinch roll 15 and the intelligent plate rolling machine 16 for preventing the biting failure of the rolled plate tip into the intelligent plate rolling machine 16.

  Downstream of the intelligent plate rolling machine 16, a light rolling mill rear surface pinch roll 17 is installed. In the figure, a pinch roll having an upper roll having a diameter larger than that of the upper work roll of the intelligent plate rolling mill 16 is shown as the rear pinch roll 17 of the light rolling mill, but the material to be straightened (rolled material) S is vertical. What is necessary is just to restrain the position of a direction. Therefore, a small-diameter roll that is not driven may be used, but it is more preferable to have a structure that can apply tension. Between the cooling device 12 and the intelligent plate rolling mill 16, there may be a plurality of devices for finishing processes such as shearing and heat treatment. Rather, since there is a possibility that the shearing and heat treatment processes may cause the plate shape to change, it is preferable that the shearing and heat treatment processes be arranged upstream of the intelligent plate rolling mill 16. In addition, it is preferable in terms of productivity that the finish rolling mill 11 and the cooling device 12 and the cooling device 12 and the intelligent plate rolling machine 17 are directly connected by a roller table. It may be in the form of being connected by other transportation means such as.

A basic experiment was conducted using the above equipment.
A thick plate material called a general material is manufactured by being slowly cooled by the cooling device 12. At this time, when the temperature distribution in the plate width direction was measured with the thermometer 14, the deformation resistance in the plate width direction of the material cooled to room temperature on the cooling floor although the plate edge portion was slightly lower in temperature than the plate center portion was sampled. As a result of cutting and measuring by performing a tensile test, there was almost no difference in deformation resistance in the plate width direction. A thick plate material called a CLC material is manufactured by being rapidly cooled by the cooling device 12. At this time, as a result of measuring the temperature distribution in the plate width direction with the thermometer 14, it is 20 at a pitch of about 50 cm in the plate width direction. The temperature distribution of ℃ ~ 60 ℃ was measured, the deformation resistance in the plate width direction of the material cooled to room temperature on the cooling floor was measured by cutting out a sample and conducting a tensile test. As a result, the pitch was about 50cm in the plate width direction. A difference was recognized, and the deformation resistance corresponding to the location where the temperature was low was 30-80 MPa proof stress greater than the deformation resistance corresponding to the location where the temperature was high. As a result of measuring the same CLC material using a thermometer at the cooling bed inlet, a temperature distribution of 1 ° C. to 10 ° C. was measured at a pitch of about 80 cm in the plate width direction.

Immediately after cooling by the cooling device, there is a good correlation between the temperature distribution measured in the plate width direction and the deformation resistance distribution in the plate width direction of the CLC material cooled to room temperature. However, the temperature distribution of the CLC material is relaxed and the temperature difference is reduced by heat transfer. Therefore, it is preferable to measure the temperature distribution of the CLC material as short as possible after the end of cooling downstream of the cooling device 12.
The relationship between the plate temperature (T _CLC ) of the CLC material and the deformation resistance (k) of the CLC material after cooling to room temperature with a thermometer downstream of the cooling facility is experimentally obtained in advance, and the temperature T _CLC and strain on the deformation resistance k are obtained. ε and a relational expression approximate expression (k = k (ε, T _CLC )) are created. Since the obtained temperature in the plate width direction may include an abnormal value, averaging processing is performed in the plate width direction (averaging is performed immediately below each divided backup roll width, in which case a threshold value is provided and abnormal data is ignored. ) To calculate the average plate temperature ( _TCLCi : i = 1, n) corresponding to the width immediately below each divided backup roll. From the obtained relational expression, when the CLC material is corrected by an intelligent plate rolling machine, the load distribution between the plate and the work roll is estimated by the intelligent plate rolling machine, and the shape is controlled by the following equation (6). The method for reaching this equation may be the method disclosed in Japanese Patent Laid-Open No. 6-262228.
p _i = p _i (H, h, k (ε, T _CLCI ), σb, σf, Δε) (6)
When there is a temperature distribution in the sheet width direction, the temperature in the sheet width direction obtained by the sheet temperature detector on the inlet side of the sheet rolling mill as described above is averaged in the sheet width direction (directly below each divided backup roll width) In this case, a threshold value is set, and abnormal data exceeding the threshold value is ignored), and the average plate temperature (T _i ′: i = 1, 17) immediately below each divided backup roll width is calculated. Between the temperature (T ₉ ′) of the warm thick plate material directly below the center of the body length of the split backup roll located at the center and the temperature of the warm plate material (T _i ′) immediately below the center of the body length of each divided width backup roll. a deviation _{(△ T = T i '-T} 9').
As described above, assuming that the linear expansion coefficient of the thick plate material is α, the difference in elongation between each divided backup roll and the center of the plate when it is cooled to room temperature is expressed as ΔL _i = α · ΔT per unit length. The When the Young's modulus of the thick plate material is E, a stress difference (Δσ _i : i = 1, 17) between the center of the plate immediately below each divided backup roll is E · ΔL _i .
Therefore, in order to prevent a stress difference from the center of the plate after cooling, this stress difference is added to the product target plate shape from the plate shape directly under each split backup roll immediately after the correction of the thick plate material during warm rolling. The shape control is performed by the method described above as the shape control target value at the time of correction. Since it takes a transfer time to the temperature detector and the straightening machine, it is preferable to perform tracking.
The plate temperature detector is desirably installed not only on the entrance side of the intelligent plate rolling machine but also on the exit side, and more accurate shape control is possible using both temperature signals.
Furthermore, in order to increase the accuracy, a tensile test piece is prepared from the CLC material after cooling to the room temperature ( _TCLC ) and the room temperature of the CLC material in advance with a thermometer downstream of the cooling equipment, and the room temperature is measured by the rolling tensile test method. The temperature effect on 0.2% proof stress was experimentally investigated by changing the ambient temperature in the temperature range from 400 ° C. to 400 ° C., and the plate temperature of the CLC material of the thermometer downstream of the cooling facility on the deformation resistance k (T _CLC ), Temperature T, strain ε, and a relational expression k = k (ε, T _CLC , T). Then, shape control is performed using the formula (7) instead of the formula (6) by the above-described method. P _i = p _i (H, h, k (ε, T _CLCI , T _i ′), σb, σf, Δε (7)
In addition, the plate temperature used here can also be a temperature measured at the entrance side of the intelligent plate rolling mill, and is not limited to the entrance side of the intelligent plate rolling mill, but is more accurate using the temperature at the exit side. Shape control can also be performed.

The rolling mill used in Example 1 of the present invention is the same as that shown in FIGS.
[Rolling conditions and main specifications]
Upper and lower work rolls: φ300mm x 5800mm (upper and lower work roll drive)
Split backup roll: φ600mm × 300mm (17 splits)
Thick plate temperature
30 ° C: (No temperature distribution: conventional conditions)
100 ° C: (plate edge 90 ° C, temperature difference 10 ° C)
200 ° C: (plate edge 185 ° C, temperature difference 15 ° C)
300 ° C: (plate edge 275 ° C, temperature difference 25 ° C)
400 ° C: (plate edge 360 ° C, temperature difference 40 ° C)
Elongation rate: 0.3%
Thick plate material: Plate thickness: 20 mm, Plate width: 5100 mm, Length: 30 m
Rolling speed: 100m / min
Table 1 shows the results of the rolling method affecting the plate shape after cooling and the warp after cutting.

The evaluation criteria in Table 1 are as follows.
・ Flatness
○: Average wave height per 1m length is within 1mm
Δ: Average wave height per 1m length is more than 1mm and within 2mm
×: Average wave height per 1m length is over 2mm. Warpage after cutting (camber)
○: Average warpage per 1m length is within 1mm
Δ: Average warpage per 1m length> 1mm to within 3mm
×: Average warpage per 1m length is over 3mm. Cutting is performed by gas cutting the entire length with a plate width of 250mm at positions of 10mm and 260mm from the plate edge on the work side and drive side, and measuring the warp (camber) after cutting. The average warpage amount per 1 m length was determined.

In the conventional rolling method that does not take into account the temperature distribution, there is no problem when straightening a normal thick plate material, but when straightening a warm thick plate material, steel type A (the effect of temperature on deformation resistance is affected). Small steel grades have good flatness after cooling, but warp after cutting. Further, in the steel type B (steel type having a small effect of temperature on deformation resistance), the flatness after cooling becomes poor when the temperature difference becomes large.
In the rolling method according to claim 1 of the present invention, the flatness after cooling is good, but with regard to warping after slicing, there is a large temperature difference between steel types A (steel types having a small effect of temperature on deformation resistance). , Steel type B (steel type having a small effect of temperature on deformation resistance) is defective. On the other hand, in the rolling method according to claim 2 of the present invention, there was no problem with respect to the flatness after cooling and the warp after cutting.

The rolling equipment used in Example 2 is shown in FIG.
[Rolling conditions and main specifications]
Upper and lower work rolls: φ300mm x 5800mm (upper and lower work roll drive)
Split backup roll: φ600mm x 300mm (17 splits)
Surface temperature immediately after cooling 650 ° C: (general material: almost no temperature distribution, conventional conditions)
600 ° C: (CLC material: temperature distribution 50 ° C)
Elongation rate: 0.3%
Thick plate material: Plate thickness: 25 mm Plate width: 5100 mm, length: 30 m
Rolling speed: 100m / min
Table 2 shows the results of the rolling method affecting the plate shape after cooling and the warp after slicing.

The evaluation criteria for the flatness and warpage (camber) after cutting in Table 2 are the same as the criteria shown in Table 1 of Example 1.
As can be seen from Table 2, in the conventional rolling method of general materials that does not take into account deformation resistance, there is no problem when forcing a thick plate material at normal temperature, but when correcting a thick plate material that is a CLC material at normal temperature. The flatness after cooling deteriorates, and warping occurs after cutting. In the rolling method according to claim 3 of the present invention, the flatness after cooling and the warp after cutting were good for both the general material and the CLC material.

It is a side view which shows the outline | summary of the intelligent type plate rolling machine used in order to implement the rolling method which concerns on this invention. It is a top view which shows the example of decomposition | disassembly of the division | segmentation backup roll in the rolling mill of FIG. It is a side view which shows the outline | summary of the thick plate material rolling equipment used in order to implement the other rolling method concerning this invention.

Explanation of symbols

1, 1 ': Upper and lower work rolls 2a, 2b: Upper / lower side divided backup roll 2a', 2b ': Lower / outer side divided backup roll 3, 3': Upper / lower work roll chock 4, 4 ' : Upper / lower inner housing 5: Mill housing 6: Pass line adjusting device 7: Hydraulic pressure reducing device 8: Incoming table roller 9: Outgoing table roller 10: Plate temperature detector 11: Finishing mill 12: Cooling device 13: Rolling material traveling direction 14: Thermometer 15: Intelligent plate rolling machine front pinch roll 16: Intelligent plate rolling machine 17: Intelligent plate rolling machine rear pinch roll

Claims (5)

At least one of the upper and lower roll assemblies has a mechanism for supporting the work roll by a divided backup roll divided into three or more in the axial direction. Each of the divided backup rolls has a load detection device, a reduction mechanism, and a reduction mechanism independently. A plate rolling machine provided with a position detecting device, at the time of correcting a warm thick plate material having a thickness distribution of 5 mm or more with a temperature distribution in the sheet width direction and a sheet surface temperature of 400 ° C. or less , at least on the sheet rolling machine entrance side The temperature in the plate width direction of the warm thick plate material is detected at, the obtained temperature signal is averaged, and the temperature of the warm thick plate material directly below the center of the trunk length of the central divided backup roll and each divided width backup Obtain the deviation from the temperature of the warm thick plate just below the center of the body length of the roll, and eliminate the influence of the amount of thermal expansion on the plate shape of the straightened material after cooling based on the obtained temperature deviation. As such, the rolling method of thick plate material and controlling an adjustment to the shape and the residual stress of the displacement of each divided backup rolls of the plate mill. In the rolling method of the thick plate material according to claim 1, the deformation resistance of the warm thick plate material immediately below the center of the body length of each divided backup roll is estimated based on the obtained averaged temperature signal, and the plate rolling Calculate the shape directly under each split backup roll of the mill, and control the shape and residual stress by adjusting the displacement of each split backup roll of the plate rolling mill so that the obtained plate shape becomes a preset target value A method for rolling a thick plate material. At least a finishing rolling mill and a cooling device for a thick plate rolled by the finishing rolling mill, and after controlled cooling by the cooling device , at least one of the upper and lower roll assemblies is divided into three or more parts in the axial direction. A thick steel plate having a mechanism for supporting a work roll by a divided backup roll, and a plate rolling machine provided with a load detection device, a reduction device, and a roll position detection device independently for each divided backup roll. the rolling equipment, when correcting or less thick plates no temperature distribution in the plate thickness 5mm or more in the plate width direction is to be straightened material, detecting the temperature of the plate width direction of the straightening member in the cooling device outlet side If there is a difference of more than 20 ° C. in the plate width direction when, Starring the deformation resistance of the straightening member immediately below the divided backup rolls plate rolling mill at the time of straightening the resultant temperature And, by using the deformation resistance estimating a plate shape at the time of correction of the plate rolling mill, and controlling the shape of a flat plate and residual stress so that this plate-shaped to match the pre-specified target plate shape Thick plate rolling method. When correcting a plate material with a temperature distribution in the plate width direction of 5 mm or more, which is a material to be corrected, the temperature in the plate width direction of the warm plate material is measured at least with a temperature detector installed on the inlet side of the plate rolling machine. The detected temperature signals are averaged, and the temperature of the warm thick plate material just below the center of the trunk length of the center divided backup roll and the temperature of the warm thick plate material just below the center of the trunk length of each divided width backup roll In order to eliminate the influence of the thermal expansion amount on the plate shape of the straightened material after cooling based on the obtained temperature deviation, the displacement of each divided backup roll of the plate rolling mill is adjusted to obtain the shape and The method for rolling a thick plate according to claim 3, wherein residual stress is controlled .     5. The method for rolling thick plates according to claim 4, wherein the deformation resistance is calculated by using the detected temperature of the straightened material on the outlet side of the cooling device and the detected temperature of the straightened material on the inlet side of the sheet rolling mill.

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