Title of the invention: Manufacturing method and control device for slabs
Technical field
[0001]
　The present invention relates to a slab manufacturing method and a control device.
　This application claims priority based on Japanese Patent Application No. 2018-198356 filed in Japan on October 22, 2018, the contents of which are incorporated herein by reference.
Background technology
[0002]
　As shown in Patent Document 1, for example, a twin-drum type continuous casting apparatus is used for manufacturing a metal strip (hereinafter referred to as a slab). In the twin-drum type continuous casting device, a pair of continuous casting casting drums (hereinafter referred to as casting drums) are arranged in parallel, and the facing peripheral surfaces are rotated from above to downward, respectively, and formed by the peripheral surfaces of these casting drums. The molten metal is poured into the molten metal pool, and the molten metal is cooled and solidified on the peripheral surface of the casting drum to continuously cast the metal strip. The pair of casting drums presses the slab with a predetermined pressing force while maintaining the parallelism of the rotating shafts during casting. The reaction force from the slab to the casting drum changes depending on the solidification state and may become non-uniform in the width direction, and it is difficult to strictly maintain the parallelism of the rotation axes of the pair of casting drums. For this reason, a difference in plate thickness at both ends in the width direction, so-called wedge, may occur in the slab. When wedges are generated, meandering may occur in a rolling mill located downstream in the casting direction of the casting drum, which may cause plate passing trouble.
[0003]
　For example, as a method for suppressing meandering in a rolling mill, Patent Document 1 states that while a pair of casting drums are kept parallel to each other, the opening / closing, crossing angle, and offset amount of the casting drums are controlled to control the slab. Techniques for adjusting crowns and wedges are disclosed.
[0004]
　Patent Document 2 describes a twin-drum type continuous casting machine in which a molten metal is cast into a surface gap between two drums having parallel rotation axes and holding an arbitrary gap and rotating in opposite directions to cast a thin plate. A reduction control method is disclosed. In this method, the pressing force at both ends of one drum is detected and added, and a signal based on this is used to hydraulically press both ends of the other drum so that the sum of the pressing forces at both ends of one drum becomes a predetermined value. The wedge is reduced by moving it in parallel by the cylinder.
[0005]
　Patent Document 3 describes a rolling start method in which the roll interval of an in-line mill is narrowed to a target position at the time of rolling after detecting the passage of a dummy sheet attached to the tip of a slab sent out from a twin drum with a plate thickness gauge on the outside of the mill. It has been disclosed. In such a method, the roll cross angle or roll bending force of the rolling mill is changed to suppress meandering of the slab.
[0006]
　Patent Document 4 discloses a technique relating to a meandering control method for controlling meandering of thin strip slabs manufactured by a twin-drum type continuous casting machine. In such a method, the difference between the left and right gaps in the hot rolling mill is adjusted based on the difference in the amount of meandering of the slab detected at two or more points on the entry side of the rolling mill to suppress the meandering of the thin strip slab.
[0007]
　Further, Patent Document 5 discloses a technique relating to a control method for controlling meandering in a rolling mill. The method of this document discloses a technique for controlling the wedge ratio between the entry side and the exit side based on the plate thickness detected by the sensor provided between the rolling stands.
[0008]
　Further, in Patent Document 6, when the plate thickness is obtained in the case where the plate thickness gauge is not installed in the rolling reduction setting control method, the mill stretch is used as the contribution of each work roll deformation and the deformation other than the work roll. It is disclosed that the plate thickness is estimated separately from the contribution of.
Prior art literature
Patent documents
[0009]
Patent Document 1: Japanese Patent Application Laid-Open No. 2017-196636
Patent Document 2: Japanese Patent Application Laid-Open No. 01-166863
Patent Document 3: Japanese Patent Application Laid-Open No. 2000-343103
Patent Document 4: Japanese Patent Application Laid-Open No. 2003-039108 JP
Patent Document 5: Japanese Patent Laid-Open 09-168810 discloses
Patent Document 6: Japanese Sho 60-030508 Patent Publication
Outline of the invention
Problems to be solved by the invention
[0010]
　In order to control and suppress the wedge that can cause meandering with high accuracy, a thickness distribution meter or the like for measuring the plate thickness is installed downstream of the casting direction of the casting drum as in the technique described in Patent Document 1, and the thickness distribution meter is installed. It is conceivable to carry out feedback control to control the plate thickness using the measurement result of. At this time, in order to reduce the dead time until the measured value of the thickness is reflected in the control of the wedge, it is desirable to install the thickness distribution meter as close to the casting device as possible. However, if the thickness distribution meter is installed directly under the casting apparatus, if the extraction of the molten metal fails, the molten metal may fall on the thickness distribution meter and damage the thickness distribution meter. Therefore, the thickness distribution meter needs to be installed at a certain distance from the casting drum. As the thickness distribution meter moves away from the casting drum, the dead time until the measured value of the thickness distribution meter is reflected in the wedge control increases, so it is difficult to control the wedge by feedback control with high accuracy.
[0011]
　Further, in the technique described in Patent Document 2, the rigidity of the cast drum is not always equal at both ends, and the wedge is reduced even if the cast drum is moved in parallel by the hydraulic cylinder so as to aim at the sum of the pressing forces. It is not always possible to suppress meandering.
[0012]
　Patent Document 3 does not describe the reduction of wedges, and even if an attempt is made to suppress the wedges by the technique described in Patent Document 3, if the wedges are large, there is a possibility that a sheeting trouble due to meandering or narrowing may occur. ..
[0013]
　In the technique described in Patent Document 4 or Patent Document 5, since the left and right rolling positions of the work roll cannot be appropriately set, non-uniformity in the advance rate and the reverse rate occurs on the left and right sides of the rolling mill, and the material on the side of entering the rolling mill. The speed becomes uneven on the left and right. The meandering amount on the rolling mill entry side is determined by this material speed difference, but it takes time from setting the rolling down position of the work roll until the material speed difference caused by the rolling down position appears in the meandering amount. Therefore, even if the meandering control is performed, the control may not be in time, which may lead to a board passing trouble.
[0014]
　Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to manufacture a slab in a continuous casting facility having a twin drum type continuous casting apparatus and a rolling mill. It is an object of the present invention to provide a new and improved casting method and control device for slabs, which can further reduce meandering in a rolling mill and reduce sheeting troubles.
Means to solve problems
[0015]
(1) In the method for producing a slab according to one aspect of the present invention, a pair of a twin drum type continuous casting apparatus for solidifying molten metal with a pair of rotating casting drums to cast the slab and a pair of cast slabs. In a rolling mill that rolls with a work roll, and in a slab manufacturing method that produces slabs using, the deformation characteristics of the housing that supports the casting drum acquired before the start of casting of the slab and the rolling down of the casting drum. Casting drum housing showing the deformation characteristics of the rolling system Using the rolling system deformation characteristics of the cast drum housing, the estimated plate thickness at both ends in the width direction of the slab is calculated from the following formula 1, and the estimated plate thickness calculated from the formula 1 is obtained. Based on this, the inlet wedge ratio, which indicates the ratio between the inlet wedge and the inlet plate thickness of the slab, which is the difference in the plate thickness at both ends on the inlet side of the rolling mill, is calculated, and both ends on the outlet side of the rolling mill are calculated. Calculate the exit side wedge ratio, which indicates the ratio between the exit side wedge and the outside plate thickness of the slab, which is the difference in plate thickness, so that the difference between the inlet side wedge ratio and the exit side wedge ratio is within a predetermined range. In addition, the rolling position of the rolling mill is adjusted.
(Estimated plate thickness on the input side of the rolling mill) = (Casting cylinder rolling position)
　　　　　+ (Casting drum elastic deformation)
　　　　　+ (Casting drum housing rolling system deformation)
　　　　　+ (Casting drum drum profile)
　　　　　-( Casting position zero point adjustment ) casting elastic deformation of the drum) formula 1 in
the manufacturing method of the cast slab according to (2) above (1), the delivery side thickness used to calculate the exit side wedge ratio, slab just below the roll bite It may be estimated by the following equation 2 using the position information in the width direction of.
(Estimated plate thickness on the exit side of the rolling mill) = (Rolling cylinder rolling position)
　　　　　+ (Elastic deformation of work roll)
　　　　　＋ (Rolling machine housing reduction system deformation)
　　　　　＋ (Roll profile of work roll)
　　　　　-(Elastic deformation of work roll when rolling down position zero is adjusted) ・ ・ ・ Equation 2
(3) Manufacture of the slab according to (1) above. In the method, the output side plate thickness used for calculating the output side wedge ratio may be an actually measured value of the plate thickness of the slab on the output side of the rolling mill.
(4) In the method for manufacturing a slab according to any one of (1) to (3) above, the casting drum housing reduction system deformation characteristic is a pair of side dams provided at the widthwise end of the casting drum. Based on the rolling position and load of the casting cylinder obtained by performing tightening with a plate having a plate width longer than the drum length of the casting drum and a uniform plate thickness sandwiched between the casting drums. May be obtained.
(5) In the method for manufacturing a slab according to any one of (1) to (4) above, the reduction position zero adjustment of the casting drum is performed by a pair of side dams provided at the widthwise end of the casting drum. It may be performed in a state where a plate having a plate width longer than the drum length of the casting drum and a plate thickness having a uniform thickness is sandwiched between the casting drums.
[0016]
(6) In the control device according to one aspect of the present invention, a twin-drum type continuous casting device in which molten metal is solidified by a pair of rotating casting drums to cast slabs, and a pair of work rolls in which the cast slabs are cast. A control device for adjusting the rolling position of a rolling mill in a slab manufacturing facility having a rolling mill, the control device is a housing that supports a casting drum acquired before the start of casting of the slab. The estimated plate thickness at both ends in the width direction of the slab is calculated from the following equation 1 using the deformation characteristics of the cast drum housing rolling system, which shows the deformation characteristics of Using the calculation unit and the estimated plate thickness, the inlet wedge ratio, which indicates the ratio between the inlet wedge, which is the difference between the plate thicknesses at both ends on the inlet side of the rolling mill, and the inlet plate thickness of the slab, is obtained and rolled. A ratio calculation unit for obtaining the exit side wedge ratio, which is the difference between the plate thicknesses at both ends on the exit side of the machine, and the exit side wedge ratio, which indicates the ratio between the exit side plate thickness of the slab, and the entry side wedge ratio and the exit side. A control unit for adjusting the rolling position of the rolling mill is provided so that the difference from the wedge ratio is within a predetermined range.
(Estimated plate thickness on the input side of the rolling mill) = (Casting cylinder rolling position)
　　　　　+ (Casting drum elastic deformation)
　　　　　+ (Casting drum housing rolling system deformation)
　　　　　+ (Casting drum drum profile)
　　　　　-( Casting position zero point adjustment ) Elastic deformation of the casting drum in) ... Equation 1
The invention's effect
[0017]
　According to the present invention, when a slab is manufactured in a continuous casting facility having a twin drum type continuous casting apparatus and a rolling mill, it is possible to further reduce meandering in the rolling mill and reduce plate passing trouble. ..
A brief description of the drawing
[0018]
FIG. 1 is a schematic cross-sectional view showing a slab manufacturing facility according to an embodiment of the present invention.
[Fig. 2] Fig. 2 is a schematic diagram showing an example of the configuration of a cast drum.
[Fig. 3] Fig. 3 is a schematic diagram showing the state of meandering in a rolling mill.
[Fig. 4] Fig. 4 is a schematic diagram showing an example of wedge generation in a cast drum.
[Fig. 5] Fig. 5 is a schematic diagram showing a state of rolling in a rolling mill to reduce meandering.
[Fig. 6] Fig. 6 is a schematic diagram showing an example of acquiring position information of a slab in a rolling mill.
[Fig. 7] Fig. 7 is a schematic diagram showing an example of acquiring the deformation characteristics of a cast drum housing reduction system.
FIG. 8 is a schematic diagram showing an example of adjusting the reduction position zero point of a casting drum.
[Fig. 9] Fig. 9 is a schematic view showing an example of adjusting the reduction position zero point of a casting drum.
[Fig. 10] Fig. 10 is a schematic diagram showing an example of adjusting the reduction position zero point of a casting drum.
[Fig. 11] Fig. 11 is a schematic cross-sectional view showing an example of a modification of a slab manufacturing facility according to the same embodiment.
Embodiment for carrying out the invention
[0019]
　Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.
[0020]
　In the present specification, the numerical range represented by using "-" means a range including the numerical values ​​before and after "-" as the lower limit value and the upper limit value. In the present specification, the term "process" is used not only as an independent process but also as long as the intended purpose of the process is achieved even if it cannot be clearly distinguished from other processes. included. Further, it is obvious that each element of the following embodiments can be combined.
[0021]
　(1. Continuous Casting Equipment)
　An example of the configuration of a continuous casting equipment for manufacturing slabs will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing a continuous casting facility 1 for manufacturing slabs. FIG. 2 is a plan view showing an example of a configuration in which the continuous casting apparatus 10 is viewed from directly above in the casting direction.
[0022]
　Referring to FIG. 1, the continuous casting equipment 1 includes a double drum type continuous casting apparatus 10 (hereinafter referred to as a continuous casting apparatus 10), a first pinch roll 20, a rolling mill 30, a control device 100, and meandering. A total of 110, a second pinch roll 40, and a winding device 50 are provided.
[0023]
　The continuous casting device 10 has a pair of casting drums including a first casting drum 11 and a second casting drum 12. The pair of cast drums are arranged so as to face each other in the horizontal direction. The continuous casting apparatus 10 rotates the first casting drum 11 and the second casting drum 12 in different circumferential directions so that the facing surfaces of the pair of casting drums are extended downward, and the peripheral surfaces of these casting drums are rotated. The molten metal poured into the molten metal pool formed by the above is cooled and solidified on the peripheral surface of the casting drum to continuously cast the slab S.
[0024]
　Here, the configuration of the continuous casting apparatus 10 will be described with reference to FIG. Referring to FIG. 2, in the continuous casting apparatus 10, the first casting drum 11 and the second casting drum 12 are arranged so as to face each other in the horizontal direction, and the slab is placed between the first casting drum 11 and the second casting drum 12. Is cast. The first casting drum 11 and the second casting drum 12 are rotated by the drive of the motor M, and the slab S is sent downstream in the casting direction.
[0025]
　In the continuous casting apparatus 10, the side dam 15d is provided so as to surround a gap formed by the first casting drum 11 and the second casting drum 12 facing each other at both ends of the first casting drum 11 and the second casting drum 12 in the width direction. And a side dam 15w is provided. The molten metal is stored in a region surrounded by the first casting drum 11 and the second casting drum 12, and the side weir 15d and the side weir 15w, and the slab S is sequentially cast.
[0026]
　Both ends of the widthwise axis of the first cast drum 11 and the second cast drum 12 are supported by the housing 13d and the housing 13w, respectively. Both ends of the shaft of the second casting drum 12 are connected to connect both ends of the shaft of the second casting drum 12 in the horizontal direction facing the casting drum 12 on the side opposite to the side where the first casting drum 11 is arranged. The unit 19 is provided. The connecting portion 19 is connected to the cylinder 17 on the side opposite to the side where the second casting drum 12 is arranged. The cylinder 17 can compress the casting drum in the horizontal direction in which the casting drum faces. When the cylinder 17 presses down the connecting portion 19, the second casting drum 12 can move in the horizontal direction in which the casting drum faces. By moving the second casting drum 12, the slab S can be reduced by the first casting drum 11 and the second casting drum 12.
[0027]
　At both ends of the shaft of the first casting drum 11, load cells 14d and load cells 14w for measuring the load applied to the first casting drum 11 are provided on the side opposite to the side on which the cylinder 17 is arranged. Thereby, the load due to the reduction of the cylinder 17 can be measured.
[0028]
　The slab S cast from the continuous casting apparatus 10 is sent to the rolling mill 30 by the first pinch roll 20.
[0029]
　The rolling mill 30 rolls the slab S to a desired plate thickness. The rolling mill 30 includes an upper work roll 31 and a lower work roll 32, and an upper backup roll 33 and a lower backup roll 34 that support the upper work roll 31 and the lower work roll 32. The rolling mill 30 is rolled by sandwiching the slab S with the upper work roll 31 and the lower work roll 32.
[0030]
　A control device 100 and a meandering meter 110 are provided upstream of the rolling mill 30 shown in FIG. 1 in the rolling direction. The meandering meter 110 has a function of acquiring the position information of the slab S with respect to the work roll of the rolling mill 30. The meandering meter 110 also has a function of outputting the acquired position information to the control device 100.
[0031]
　The meandering meter 110 may be an image pickup device such as a camera. In this case, the position information of the slab S can be acquired by performing image processing on the captured image. In the present embodiment, the meandering total 110 is taken as an example for acquiring the position information, but the form is not limited as long as the position information can be acquired. For example, the position information of the slab S may be acquired by using a thermometer in the width direction instead of the meandering meter 110, and a split looper may be installed on the pass line of the slab S to obtain the position information from the looper. The position information of the slab S may be acquired by using the tension.
[0032]
　Further, in the present embodiment, the meandering meter 110 is installed upstream in the rolling direction of the rolling mill 30, but the meandering meter 110 may be installed downstream in the rolling direction. The location of the meandering meter 110 is upstream or downstream in the rolling direction of the rolling mill 30, and the closer it is to the rolling mill 30, the more quickly the position information of the slab S can be obtained.
[0033]
　The control device 100 includes a plate thickness calculation unit, a ratio calculation unit, and a control unit. The control device 100 has a function of acquiring position information in the width direction of the slab S from the meandering meter 110 and controlling the rolling mill 30 based on the position information. Details of the operation of the control device 100 will be described later.
[0034]
　The rolling mill 30 is controlled by the control device 100. For example, when rolling the slab S, the control device 100 controls the rolling positions of the upper work roll 31 and the lower work roll 32 based on the measurement result of the meandering meter 110.
[0035]
　The slab S rolled to a desired plate thickness by the rolling mill 30 is sent to the winding device 50 by the second pinch roll 40, and is wound into a coil by the winding device 50.
[0036]
　(2. Rolling method of slabs)
　The rolling method of slabs described below is a continuous casting facility having a twin-drum type continuous casting device and a rolling mill, in which the meandering of the slabs is further reduced by the rolling mill. Related to technology to reduce board troubles.
[0037]
　The meandering in the rolling mill 30 will be described with reference to FIGS. 3 and 4. FIG. 3 is a schematic plan view showing the state of meandering of the slab S in the rolling mill 30, and is a view of the plate surface of the slab S from the upper work roll 31 side. FIG. 4 is a schematic plan view showing a state in which a slab in which a wedge is generated is cast.
[0038]
　Referring to FIG. 3, the slab S rolled by the upper work roll 31 and the lower work roll 32 does not proceed parallel to the rolling direction, and the plate passing position of the slab is relative to the rolling direction. There is a meandering movement in the perpendicular direction. Meandering is caused by asymmetric rolling of one end and the other end of the upper work roll 31 and the lower work roll 32, that is, left and right. Such meandering of the slab S may occur before being rolled by the rolling mill 30, that is, due to the shape of the plate thickness of the slab S at the time of casting.
[0039]
　For example, as shown in FIG. 4, the continuous casting apparatus 10 may cast a slab S whose plate thickness gradually changes from one end in the width direction toward the other end. In the slab S of FIG. 4, the plate thickness t 1 at one end is thicker than the plate thickness t 2 at the other end .
[0040]
　When the slab S in which the plate thickness is not uniform and the wedges are formed is rolled by the rolling mill 30, the thick portion is stretched larger than the thin portion. The rolling reduction ratio in the rolling mill 30 is larger at the end portion on the plate thickness t 1 side than on the plate thickness t 2 side on the rolling mill 30 entry side . In this case, the material speed in the rolling mill 30 the entry side of the slab S during rolling, thickness at entrance side t 2 t than the side 1 end side becomes small. In this way, the difference in material speed between one end and the other end of the slab S, that is, rotation occurs in the plane of the slab S, so that meandering occurs. In order to reduce the occurrence of meandering, it is effective to suppress the difference in material speed between one end and the other end of the slab S as described above and roll the slab so as to have a desired output plate thickness.
[0041]
　The present inventors have diligently studied a rolling method for rolling so as to obtain a desired output plate thickness by suppressing the difference in material speed between one end and the other end of the slab S, and using the rolling mill 30. We have found a rolling method that suppresses meandering and troubles in passing plates. This will be described with reference to FIG.
[0042]
　FIG. 5A shows a state in which the slab S in which wedges are generated is being rolled in the rolling mill 30, and a cross section in the width direction of the slab S on the entry side and the exit side of the rolling mill 30. FIG. 5 is an example of a cross-sectional view of a slab that causes meandering in a longitudinal direction (transportation direction). As shown in FIG. 5 (b), before rolling, i.e. at the inlet side of the rolling mill 30, the slab S is the thickness H of the end D thickness H of the other end W thinner than one in the width direction It is a shape in which the plate thickness gradually changes from one to the other. When rolled such slab S in the rolling mill 30, as shown in FIG. 5 (c), the slab S at the delivery side of the rolling mill 30, for example, one end of the plate thickness h D is other end plate thickness H W and became a shape that is.
[0043]
　In the rolling mill 30 according to the present embodiment, in order to suppress the material speed difference in the width direction of the slab S generated during rolling in the rolling mill 30, wedges are used so that the rolling reduction ratios of the slab S in the width direction are substantially the same. The slab S in which is generated is rolled. In this case, the inlet side wedge ratio ((the thickness H D - thickness H W ((thickness h) / thickness at entrance side) and the exit-side wedge ratio D - thickness h W seeking a) / delivery side thickness) From these differences, it is determined whether the rolling reduction rates of the slab S in the width direction are substantially the same, and the rolling position of the rolling mill 30 is controlled. If the rolling reduction in the width direction of the slab S is substantially the same, there is no difference in material speed in the width direction of the slab S, and rotation does not occur in the plane of the slab S, so that meandering occurs in the rolling mill. It can be suppressed.
[0044]
　To realize such a rolling method, the thickness calculation unit of the control device 100 first is the difference between the plate thickness of the both end portions of the slab S at the entry side of the rolling mill inlet side wedge (thickness H D - thickness H W to calculate a) The thickness at entrance side of the slab S, the center in the width direction of the plate thickness H of the slab S C may be.
[0045]
　Next, the plate thickness calculation unit shows the ratio between the output side wedge (plate thickness h D -plate thickness h W ), which is the difference in plate thickness at both ends of the rolling mill, and the output side plate thickness of the slab. Calculate the exit side wedge ratio (%). The plate thickness on the protruding side of the slab S may be the plate thickness h C at the center of the slab S in the width direction .
[0046]
　Further, the ratio calculation unit of the control device 100 obtains the difference between the entry side wedge ratio (%) and the exit side wedge ratio (%).
[0047]
　After that, the control unit of the control device 100 adjusts the rolling position of the rolling mill so that the difference is within a predetermined range. The predetermined range of the difference between the entry side wedge ratio and the exit side wedge ratio may be empirically obtained from, for example, the meandering amount that can be tolerated in actual operation. Further, the value may be 0% or more and 2% or less. Since the upper limit of the magnitude of the difference is 2%, meandering in the rolling mill 30 can be reduced more reliably. As a result, the material speed difference between one end and the other end of the slab S can be suppressed, and meandering can be suppressed.
[0048]
　Hereinafter, each process will be described in detail.
[0049]
　(Method of calculating the entrance side wedge ratio of the rolling mill)
　First, the calculation method of the entry side wedge ratio in the plate thickness calculation unit will be described. The slab S to be rolled by the rolling mill 30 is cast by the continuous casting apparatus 10 arranged upstream of the rolling mill 30 in the rolling direction. In the present embodiment, the plate thickness of the slab S cast by the continuous casting apparatus 10 is calculated and used as the input side plate thickness of the rolling mill 30 to calculate the wedge ratio on the input side of the rolling mill. As a result, the plate thickness of the slab S on the entrance side of the rolling mill 30 can be obtained without installing a plate thickness gauge or the like on the entry side of the rolling mill 30.
[0050]
　The plate thickness of the slab S on the entry side of the rolling mill 30 is estimated from the drum gap of the casting drum. The drum gap of the casting drum changes depending on the cylinder reduction position, the load applied to the casting drum, the contact with the slab, and the like. Changes in the drum gap due to the load applied to the casting drum, contact with the slab, etc. contribute to the contribution of elastic deformation of the casting drum, the contribution of elastic deformation other than the drum, and the contribution of the change in the drum profile of the casting drum. Can be considered separately. The contribution of elastic deformation other than the cast drum is called the cast drum housing reduction system deformation. From this, the inlet plate thickness of the rolling mill 30 can be estimated by the following equation 1 using various conditions of the casting drum.
[0051]
　(Estimated plate thickness on the input side of the rolling mill) = (Casting cylinder rolling position)
　　　　　+ (Casting drum elastic deformation)
　　　　　+ (Casting drum housing rolling system deformation)
　　　　　+ (Casting drum drum profile)
　　　　　-( Casting position zero point adjustment ) Elastic deformation of the casting drum in) ... Equation 1
[0052]
　However, in the formula 1, the reduction position of the casting cylinder and the deformation of the reduction system of the casting drum housing each represent the difference from the time when the reduction position zero point is adjusted. The difference may be a difference with respect to the cylinder reduction position at the time of adjusting the reduction position zero point and the deformation of the cast drum housing.
[0053]
(Cylinder reduction position) The
　cylinder reduction position indicates the reduction position of the cylinder 17 in the pressing direction of the cylinder 17 of the continuous casting apparatus 10 shown in FIG. For example, the reduction position of the cylinder indicates the position due to the difference from the initial value, which is the zero point where the position of the cylinder is adjusted to the zero point. The reduction position of the cylinder can be obtained from the displacement in the direction along the arrow a in FIG. 2 or FIG. The reduction position of the cylinder can be timely measured by a position sensor or the like (not shown) capable of measuring the movement amount of the cylinder 17.
[0054]
(Elastic deformation
　of the casting drum ) The elastic deformation of the casting drum at the time of casting indicates the elastic deformation of the casting drum at an arbitrary time point from the start of casting to the end of casting. In the casting drum, the shaft of the casting drum is bent or the casting drum is flatly deformed due to the reaction force from the slab that comes into contact with the casting drum and the influence of the external force applied to the casting drum. These deformations are called elastic deformations of the casting drum during casting. The elastic deformation of the cast drum can be obtained by means such as analysis using the elastic theory.
[0055]
　For example, the bending of the shaft of the casting drum due to the contribution of the drum deformation of the casting drum can be calculated from the bending calculation of the beam of the strength of materials by regarding the casting drum as a support beam at both ends. Regarding the load distribution in the width direction used in the deflection calculation, there is no problem assuming a linear distribution in the width direction based on the load cell values ​​provided at both ends of the shaft of the casting drum.
[0056]
(Deformation of the casting drum housing reduction system) The
　casting drum housing reduction system deformation characteristics are the characteristics that the housing 13d and the housing 13w are deformed under the influence of the reduction load applied to the casting drum, and the casting drum including the cylinder 17 is reduced. The characteristic that the composition is deformed and the deformation characteristic that includes are shown. The casting drum housing reduction system deformation of the above formula 1 indicates the deformation amount of the casting drum housing calculated using the casting drum housing reduction system deformation characteristics. For example, the deformation characteristics of the cast drum housing reduction system can be obtained by using the method described in Patent Document 6. The deformation of the cast drum housing reduction system can be calculated based on the load measured by the load cell 14d (or the load cell 14w) or the like, as will be described later.
[0057]
(Drum Profile of
　Casting Drum ) The drum profile of a casting drum is an index indicating the amount of thermal expansion of the casting drum or the amount of wear of the casting drum. In the drum profile of a casting drum, the amount of thermal expansion is calculated as the amount of deformation of the surface shape of the casting drum based on the heat applied to the casting drum. The amount of wear may be measured by actually measuring the drum profile before casting, or may be estimated from the casting conditions. For example, since the surface shape at the time of designing a cast drum is known, the amount of deformation of the drum profile can be obtained by adding the shape deformation due to thermal expansion and wear to the surface shape.
[0058]
(Elastic deformation of the casting drum when adjusting the reduction position zero point) The elastic deformation
　of the casting drum when adjusting the reduction position zero point is the casting when adjusting the reduction position zero point, which determines the initial value of the reduction position of the casting drum before the start of casting. Shows the elastic deformation of the drum. Since the reduction position zero adjustment is performed with a load applied to the casting drum, elastic deformation occurs in the casting drum. The amount of elastic deformation at that time is defined as the elastic deformation of the casting drum when the reduction position zero is adjusted. This elastic deformation amount can be calculated from the bending calculation of the beam of the strength of materials in which the drum is regarded as the support beam at both ends, similar to the elastic deformation of the cast drum at the time of casting.
[0059]
　As described above, the estimated plate thickness is calculated from the sum of the values ​​of "casting cylinder reduction position", "casting drum elastic deformation", "casting drum housing reduction system deformation", and "casting drum drum profile". It is obtained by reducing the value of "elastic deformation of the casting drum when adjusting the reduction position zero point of the casting drum".
[0060]
　Since the outer plate thickness of the continuous casting apparatus 10 due to the gap between the casting drums obtained by the above formula 1 is equivalent to the plate thickness of the slab on the inlet side of the rolling mill 30, the outer plate thickness of the continuous casting apparatus 10 The plate thickness at both ends of the slab S can be obtained from. Then, the entry side wedge ratio can be calculated from the plate thickness difference between both ends and the plate thickness at the center of the slab S in the width direction.
[0061]
　(Method of calculating the output side wedge ratio of
　the rolling mill ) Next, a method of calculating the output side wedge ratio of the rolling mill 30 will be described. The exit side plate thickness can be estimated using, for example, the following equation 2 for calculating the gap between the upper work roll 31 and the lower work roll 32. If the distribution of the gap between the upper work roll 31 and the lower work roll 32 in the width direction is known, the profile of the slab S rolled by the upper work roll 31 and the lower work roll 32 can also be estimated.
[0062]
(Estimated plate thickness on the exit side of the rolling mill) = (Rolling cylinder rolling position)
　　　　　+ (Work roll elastic deformation)
　　　　　+ (Rolling machine housing rolling system deformation)
　　　　　+ (Work roll roll profile)
　　　　　-( Rolling position zero point adjustment ) Elastic deformation of the work roll in) ... Equation 2
[0063]
　The rolling cylinder reduction position indicates the position of the cylinder in the direction in which the cylinder that reduces the work roll of the rolling mill is reduced. For example, the reduction position of the cylinder indicates the position due to the difference from the initial value, which is the zero point where the position of the cylinder is adjusted to the zero point.
[0064]
　The elastic deformation of the work roll means the elastic deformation of the work roll at an arbitrary time point from the start of rolling to the end of rolling. In the work roll, the reaction force from the slab or backup roll that comes into contact with the work roll and the influence of the external force applied to the work roll cause the work roll shaft to bend or the work roll to flatten. do. These deformations are called elastic deformations of the work roll. The bending of the shaft of the work roll and the flat deformation of the work roll, which are elastic deformations of the work roll, can be obtained by using, for example, the method described in Patent Document 6.
[0065]
　The rolling machine housing reduction system deformation characteristics include the characteristics that the housing that supports the work roll and the like is deformed under the influence of the rolling load applied to the work roll, and the characteristics that the configuration that reduces the work roll including the cylinder is deformed. Shows deformation characteristics including. For example, the method described in Patent Document 6 can be used to determine the deformation characteristics of the rolling mill housing reduction system.
[0066]
　The roll profile of the work roll is an index indicating the amount of thermal expansion of the work roll or the amount of wear of the casting drum. In the roll profile of the work roll, the amount of thermal expansion is calculated by calculating the amount of deformation of the surface shape of the work roll based on the heat applied to the work roll. The amount of wear may be measured by measuring the roll profile before rolling, or may be estimated from the rolling conditions. For example, since the surface shape of the work roll at the time of designing the rolling mill is known, the amount of deformation of the roll profile can be obtained by adding the shape deformation due to thermal expansion to the surface shape.
[0067]
　The elastic deformation of the work roll at the time of adjusting the zero point of the rolling position indicates the elastic deformation of the work roll at the time of adjusting the zero point of the rolling position, which determines the initial value of the rolling position of the rolling mill before the start of rolling. Since the reduction position zero adjustment is performed with a load applied to the work roll, elastic deformation occurs in the work roll. The amount of elastic deformation at that time is defined as the elastic deformation of the work roll when the reduction position zero is adjusted. This elastic deformation amount can be calculated in the same manner as the elastic deformation of the work roll during rolling.
[0068]
　As described above, the gaps between the work rolls on the exit side of the rolling mill are "rolling cylinder rolling position", "work roll elastic deformation", "rolling machine housing rolling system deformation", and "work roll roll profile". It is obtained by subtracting the value of "elastic deformation of the work roll at the time of adjusting the zero point of the rolling position" from the sum of the values ​​of.
[0069]
　Here, in order to calculate the wedge of the slab on the outlet side of the rolling mill 30, the position of the slab S in the width direction with respect to the upper work roll 31 and the lower work roll 32 of the rolling mill 30 is specified in the above formula 2. is necessary. Depending on the position of the slab S, the position of the point of action of the reaction force from the slab that comes into contact with the work roll changes, or the distribution of the reaction force exerted on the work roll from the slab S or the backup roll changes in the width direction. This is because the elastic deformation of the work roll changes, and the widthwise distribution of the gap between the upper work roll 31 and the lower work roll 32 changes.
[0070]
　Therefore, the plate thickness calculation unit acquires the position information of the slab S from the meandering meter 110 and specifies the position of the slab S in the width direction with respect to the rolling mill 30. Then, from the distribution of the gap between the work rolls obtained by the above equation 2, the plate thickness calculation unit sets the gap between the work rolls corresponding to the position in the width direction of the slab S as the protruding side plate thickness of the slab S. .. From this, a plate thickness corresponding to both ends of the slab S can be obtained. The plate thickness calculation unit calculates the exit side wedge ratio based on the plate thickness difference between both ends of the slab S and the plate thickness at the center in the width direction of the slab.
[0071]
　The position information of the slab S will be described with reference to FIG. FIG. 6 is a diagram schematically showing the rolling mill 30 as viewed from the rolling direction.
[0072]
　The position information is the position information of the slab S with respect to the work roll. The position information may be information indicating the position of the portion where the slab S is in contact with the work roll. Specifically, the position information is in a straight line connecting the center point Sc in the width direction of the slab S, the center point 31c in the width direction of the upper work roll 31, and the center point 32c in the width direction of the lower work roll 32. point W C may be a distance Y to.
[0073]
　In this way, the plate thickness calculation unit and the ratio calculation unit calculate the entry side wedge ratio and the exit side wedge ratio of the rolling mill 30. The ratio calculation unit outputs the calculated entry-side wedge ratio and exit-side wedge ratio to the control unit.
[0074]
　(Control of the rolling mill) The
　control unit acquires the entry-side wedge ratio and the exit-side wedge ratio from the ratio calculation unit, and obtains the difference between the entry-side wedge ratio and the exit-side wedge ratio. The control unit adjusts the rolling position of the rolling mill 30 so that this difference is within a predetermined range. The adjustment of the rolling mill 30 is performed by a cylinder provided in the rolling mill 30. The predetermined range (that is, the magnitude of the difference between the allowable entry side wedge ratio and the exit side wedge ratio) can be appropriately determined depending on the material of the slab, the state of the rolling mill 30, and the like, and is, for example, 0%. It may be 2% or more and 2% or less. By setting the size of the difference between the entrance side wedge ratio and the exit side wedge ratio to 2% or less, it is possible to more reliably suppress the occurrence of meandering in the rolling mill 30.
[0075]
　(3. Method for manufacturing slabs)
　Hereinafter, a specific overall procedure will be described with respect to the method for manufacturing slabs according to the above embodiment.
[0076]
　First, the plate thickness calculation unit of the control device 100 calculates the inlet plate thickness on the inlet side of the rolling mill 30. The entry side plate thickness is calculated based on the above equation 1. The continuous casting apparatus 10 is equipped with various measuring instruments such as a temperature measuring instrument for the first casting drum 11 and the second casting drum 12, and a load cell 14d and a load cell 14w for measuring a load. The plate thickness calculation unit acquires various values ​​from these various measuring instruments and calculates the estimated plate thickness at both ends of the slab from the above equation 1. The plate thickness calculation unit calculates the entry side wedge by using the plate thicknesses at both ends of the slab S having the entry side plate thickness calculated by the above formula 1.
[0077]
　Next, the plate thickness calculation unit calculates the output side plate thickness on the output side of the rolling mill 30. The exit side plate thickness is calculated based on the above formula 2. The rolling mill 30 is equipped with various measuring instruments such as a temperature measuring instrument for the upper work roll 31 and the lower work roll 32 and a load measuring instrument for measuring the load. The plate thickness calculation unit acquires various values ​​from these various measuring instruments and calculates the output side plate thickness from the above equation 2.
[0078]
　Here, the plate thickness calculation unit acquires the position information of the slab S from the meandering meter 110. The plate thickness calculation unit uses the position information to specify the position of the slab S with respect to the work roll. The plate thickness calculation unit estimates the plate thickness corresponding to both ends of the slab S from the specified position of the slab S and the output side plate thickness calculated by the above equation 2, and calculates the output side wedge.
[0079]
　Next, the ratio calculation unit is a wedge from the wedges of the slabs S on the inlet side and the outlet side of the rolling mill 30 and the plate thicknesses of the slabs on the inlet side and the outlet side of the rolling mill 30 calculated by the plate thickness calculation unit. Calculate the ratio. Specifically, the ratio calculation unit calculates the entry side wedge ratio using the entry side wedge and the plate thickness at the center in the width direction of the entry side slab or the average plate thickness of the entry side slab. , The exit side wedge ratio is calculated using the plate thickness at the center in the width direction of the exit side slab or the average plate thickness of the exit side slab.
[0080] [0080]
　Next, the control unit calculates the difference between the entry side wedge ratio and the exit side wedge ratio calculated by the ratio calculation unit, and makes the difference within a predetermined range from the cylinder of the rolling mill 30 (shown in the figure). Adjust the rolling position.
[0081]
　The details of the slab manufacturing method in the present embodiment have been described above.
[0082]
　(4. Improving the accuracy of calculating the plate thickness
　on the inlet side of the rolling mill ) In the present embodiment, the plate thickness of the slab S on the inlet side of the rolling mill 30 is estimated using various conditions of the casting drum based on the above equation 1. .. The higher the accuracy of estimating the plate thickness by the above equation 1, the higher the accuracy of the difference between the entry side wedge ratio and the exit side wedge ratio, and as a result, the meandering of the rolling mill 30 can be further suppressed.
[0083]
　Here, among the items of the above equation 1, the casting drum housing reduction system deformation characteristic showing the deformation characteristic of the configuration other than the drum largely depends on the delicate shape of the contact surface especially in the low load region, and the characteristic changes. It is easy and it is difficult to grasp the geometric shape exactly even by using a known physical model. Therefore, the present inventors have studied a method for acquiring the deformation characteristics of the cast drum housing reduction system, and have come up with the method shown below.
[0084]
　(Acquisition of Deformation Characteristics of Casting Drum Housing Reduction System) A
　method of acquiring the deformation characteristics of the casting drum housing reduction system will be described with reference to FIG. 7. FIG. 7 is a diagram showing an example of a method for acquiring the deformation characteristics of the casting drum housing reduction system.
[0085]
　As shown in FIG. 7, the acquisition of the casting drum housing reduction system deformation characteristic can be performed by sandwiching the test plate 16 between the first casting drum 11 and the second casting drum 12. The length of the test plate 16 in the longitudinal direction is longer than the barrel length in the width direction of the cast drum, and the plate thickness is uniform. From this state, the test plate 16 is pressed by the cylinder 17 and tightened, so that the test plate 16 is pressed by the first casting drum 11 and the second casting drum 12. The length of the test plate 16 in the direction perpendicular to the longitudinal direction is not limited, but the first casting drum 11 and the second casting drum can be sufficiently contacted with the first casting drum 11 and the second casting drum 12. It is more preferable that the length is about 50 to 100 cm, which is about twice the drum diameter of 12.
[0086]
　By using the test plate 16 longer than the barrel length in this way, it is possible to apply an even load to both ends of the casting drum, and it is possible to accurately obtain the deformation of the casting drum housing reduction system. The deformation of the cast drum housing reduction system indicates the relationship between the load change and the amount of deformation of the casting drum housing reduction system.
[0087]
　Specifically, a predetermined value larger than the load at the time of zero point adjustment with respect to the test plate 16 in a state where the test plate 16 is sandwiched between the casting drums and the first casting drum 11 and the second casting drum 12 are not rotated. The casting drum is tightened with a load, the rolling position of the casting drum and the load measured by the load cells 14d and 14w are acquired, and the amount of deformation of the casting drum under each load is calculated. Then, by reducing the amount of deformation of the casting drum from the rolling position of the casting drum, the amount of deformation of the casting drum housing reduction system for each load is acquired. As a result, it is possible to acquire the casting drum housing reduction system deformation characteristic indicating the amount of deformation of the casting drum housing reduction system according to the load applied to the slab S when the slab S is cast. As another method, the first casting drum 11 and the second casting drum 12 are rotated while the test plate 16 is sandwiched, and the casting drum is tightened with the above-mentioned predetermined load for a predetermined time. The load may be held and the average value of the load and the rolling position of the casting drum may be obtained. After that, the load of the casting drum may be further changed to hold the changed load for a predetermined time, and the average value between the load of another level and the reduction position of the casting drum may be obtained. Here, the time for holding each load may be two rotations of the casting drum. Further, this average value may be calculated from the time-series data of the load and the reduction position by acquiring the time-series data. In this way, the amount of deformation of the casting drum under each load is calculated, and the amount of deformation of the casting drum is reduced from the rolling position of the casting drum, so that the amount of deformation of the casting drum housing reduction system for each load is obtained. In this way, by acquiring the deformation characteristics of the casting drum housing reduction system using the test plate 16 which is longer than the barrel length in the width direction of the casting drum and has a uniform plate thickness, the casting drum due to the load applied to the casting drum during casting. The amount of deformation of the reduction system including the housing, cylinder, etc. can be obtained and reflected in Equation 1. As a result, the accuracy of the estimated plate thickness obtained by Equation 1 can be improved.
[0088]
　The acquisition of the rolling system deformation characteristics of the cast drum housing may be performed once before the start of a series of casting operations. In addition, it is possible to acquire the deformation characteristics of the cast drum housing reduction system according to the equipment conditions by performing this when a part of the configuration of the housing or the reduction system is replaced.
[0089]
　The test plate 16 is formed of, for example, a material softer than the first casting drum 11 and the second casting drum 12 so as not to crush the dimples and the like formed on the surfaces of the first casting drum 11 and the second casting drum 12. Is more preferable. The test plate 16 is not limited, but is more preferably formed of, for example, an aluminum alloy.
[0090]
　(Application to reduction position zero adjustment)
　Further, in the reduction position zero adjustment of the casting drum, as shown in FIG. 7, a pair of side dams provided at the widthwise end of the casting drum is opened, and between the casting drums. , A plate longer than the drum length of the casting drum and having a uniform thickness may be sandwiched and the casting drum may be tightened. As a result, the slab drum is tightened while the rotation axes of the casting drum are kept parallel, so that an even load can be applied to both ends of the casting drum, and the accuracy of rolling down position zero adjustment is improved. This makes it possible to improve the accuracy of the estimated plate thickness on the entry side of the rolling mill.
[0091]
　In the continuous casting apparatus 10, the reduction position zero point of the casting drum is adjusted before the operation is started. In order to estimate the drum gap in estimating the plate thickness of the slab to be rolled by the rolling mill 30, it is required that the zero point adjustment in the casting drum is performed with high accuracy.
[0092]
　First, the reduction position zero point adjustment will be described with reference to FIGS. 8 to 10. 8 to 10 are views schematically showing a casting drum at the time of adjusting the reduction position zero point before the start of casting. 8 to 10 show the concave shape of the profile emphasized for the sake of explanation.
[0093]
　As shown in FIGS. 8 to 10, the drum profile of the casting drum before the start of casting has a concave shape in the plate width direction. This is because the first casting drum 11 and the second casting drum 12 thermally expand and change with the elapsed time from the start of casting to the arrival at the time of steady casting. For the casting drum, the initial profile of the casting drum is set so that the plate profile (crown) of the slab at the time of steady casting where thermal expansion is observed becomes the desired plate profile. That is, the initial profile of the casting drum is set to a concave crown in which the drum diameter at the center of the width of the casting drum is smaller than the drum diameters at both ends of the casting drum.
[0094]
　In a casting drum to which such a concave crown is provided, a pair of casting drums are brought into contact (kiss) with each other, and the reduction position (pressing position) when a predetermined load F is applied is set to zero, and the reduction position zero point adjustment can be performed. Will be done. By adjusting the reduction position zero point, the initial value of the reduction position of the cylinder that presses the casting drum can be set.
[0095]
　However, the cast drum is provided with a concave crown as described above. Therefore, when the casting drums are brought into contact with each other (kiss) and a predetermined load F is applied to the casting drums, only both ends of the casting drums come into contact with each other. Therefore, for example, as shown in FIG. 8, the positions of the casting drums in the width direction do not completely match, and when a predetermined load F is applied to the casting drum, both ends of the first casting drum 11 and the first one are used. 2 The contact points at both ends of the casting drum 12 shift, and a shift amount x is generated, resulting in an unstable state. Therefore, the accuracy of the reduction position zero adjustment is lowered.
[0096]
　In order to avoid this, when the reduction position zero point is adjusted using the casting drum provided with the concave crown, the reduction position zero point adjustment is performed by sandwiching the thin plate 18 between the casting drums as shown in FIG. In FIG. 9, the intermediate point 18C of the length in the width direction of the thin plate 18 is the intermediate point 11C of the length in the width direction of the first casting drum 11 and the intermediate point 12C of the length in the width direction of the second casting drum 12. Since it is arranged on a straight line connecting the casting drums, there is no deviation at both ends of the casting drum. If no deviation occurs, the rotary shaft Ar1 of the first casting drum 11 and the rotary shaft Ar2 of the second casting drum 12 are parallel to each other, so that the reduction position zero point adjustment can be stably performed.
[0097]
　However, even when the thin plate 18 is sandwiched between the casting drums and the reduction position zero point is adjusted in order to suppress the deviation, as shown in FIG. 10, the intermediate point 18C of the length in the width direction of the thin plate 18 is the first. The thin plate 18 is not arranged on a straight line connecting the midpoint 11C of the width direction of the casting drum 11 and the midpoint 12C of the length in the width direction of the second casting drum 12, and the thin plate 18 is either one of the width directions of the casting drum. May be placed closer to the edge of the. In this case, as shown in FIG. 10, since the rotation axis Ar1 of the first casting drum 11 and the rotation axis Ar2 of the second casting drum 12 are not parallel to each other, the left and right sides of the casting drum (the second) even if the reduction position zero point is adjusted. 1 An error is included in both ends of the casting drum 11 and the second casting drum 12 in the width direction). If an error is included in the rolling position zero adjustment, the rolling position of the casting drum during casting includes an error, so that the accuracy is lowered when estimating the plate thickness of the rolling mill 30. Therefore, if the accuracy of the rolling position zero adjustment can be improved, meandering in the rolling mill 30 can be further reduced.
[0098]
　Therefore, as shown in FIG. 7, the pair of side dams provided at the widthwise end of the casting drum is opened to obtain the casting drum housing reduction system deformation characteristics, and the casting drum is placed between the casting drums. The reduction position zero point is adjusted while sandwiching the test plate 16 having a plate width longer than the drum length and a uniform plate thickness. As a result, the reduction position zero point adjustment can be performed with high accuracy. When the reduction position zero point adjustment is performed by such a method, the casting drum housing reduction system deformation characteristic may be acquired in the reduction position zero point adjustment.
[0099]
　(5. Modification Example)
　Next, an example of modification of the method for manufacturing a slab according to the above embodiment will be described with reference to FIG. FIG. 11 is a diagram showing an example of a modification of the method for manufacturing a slab according to the above embodiment.
[0100]
　In the method of manufacturing a slab using the slab continuous casting facility 1 shown in FIG. 11, the control device 200 outputs the measured plate thickness acquired from the plate thickness meter 210 instead of the meandering meter 110 shown in FIG. The difference is that it is used when calculating the side wedge.
[0101]
　In FIG. 11, a plate thickness meter 210 is installed downstream in the rolling direction of the rolling mill 30 of the continuous casting facility 1 for slabs. The plate thickness gauge 210 may be, for example, a thickness distribution meter capable of measuring the plate thickness in the width direction of the slab S. In this modification, the output side plate thickness used for calculating the output side wedge ratio is an actually measured value of the plate thickness meter 210 of the slab on the output side of the rolling mill 30. The control device 200 acquires the measured value of the plate thickness at both ends of the slab S from the plate thickness meter 210, and obtains the output side wedge ratio. The entry side wedge ratio is obtained in the same manner as in the above-described embodiment. The control device 200 further obtains the difference between the obtained in-side wedge ratio and the out-side wedge ratio. The control device 200 adjusts the rolling position of the rolling mill 30 so that the obtained difference is within a predetermined range. As a result, it is possible to suppress an error in the calculation process, calculate the exit side wedge, and control the rolling mill 30 with high accuracy. The plate thickness meter 210 may be installed at least downstream of the rolling mill 30 in the rolling direction.
Example
[0102]
　In this embodiment, in order to confirm the effect of the present invention, slabs were manufactured using the continuous casting equipment 1 shown in the above embodiment. The cast drum used in this example had a drum barrel length of 1000 mm. For the cylinder position, pressure, and plate thickness in the rolling mill, the values ​​of the stationary part were used. Here, the stationary portion refers to a change in the rolling position due to the rolling position control of the cylinders on the left and right of the rolling mill, which is carried out so that the difference between the in-side wedge ratio and the out-side wedge ratio of the rolling mill is small for the material to be rolled. It means a smaller part. In this example, the average value of each value in the time from 1 minute 30 seconds after the start of rolling to 1 minute 40 seconds after the start of rolling was used.
[0103]
　Various conditions and values ​​in each example and comparative example, and evaluation of plate-passability are summarized in Table 1 below. In the evaluation of plate-passability, the maximum meandering amount of less than 30 mm was evaluated as ⊚ (good), less than 80 mm was evaluated as ○ (pass), and more than 80 mm was evaluated as × (fail).
[0104]
　In the first embodiment, as a method of adjusting the reduction position zero point of the casting drum, as shown in FIG. 7, a pair of side dams provided at the widthwise end of the casting drum is opened, and the casting drum is sandwiched between the casting drums. The reduction position zero point was adjusted while sandwiching a plate that was longer than the drum length and had a uniform plate thickness. In Table 1, this reduction position zero adjustment method is described as A. The rolling mill was controlled by controlling the rolling position of the cylinders on the left and right of the rolling mill so that the difference between the wedge ratio on the incoming side and the wedge ratio on the outgoing side of the rolling mill was small.
[0105]
　In Example 2, as a method of adjusting the reduction position zero point of the casting drum, as shown in FIG. 9, a plate shorter than the drum barrel length of the casting drum was sandwiched between a pair of casting drums to adjust the reduction position zero point. In Table 1, this reduction position zero adjustment method is referred to as B. The rolling mill was controlled by controlling the rolling position of the cylinders on the left and right of the rolling mill so that the difference between the wedge ratio on the incoming side and the wedge ratio on the outgoing side of the rolling mill was small.
[0106]
　In Example 3, as a method of adjusting the reduction position zero point of the casting drum, as shown in FIG. 9, a plate shorter than the drum barrel length of the casting drum was sandwiched between a pair of casting drums to adjust the reduction position zero point. In Table 1, this reduction position zero adjustment method is referred to as B. A plate thickness gauge was installed on the outlet side of the rolling mill. The rolling mill was controlled by controlling the rolling position of the left and right cylinders provided at both ends of the rolling mill so that the difference between the incoming wedge ratio and the outgoing wedge ratio became zero.
[0107]
　In Comparative Example 1, as a method of adjusting the reduction position zero point of the casting drum, as in Example 2, a plate shorter than the drum barrel length of the casting drum as shown in FIG. 9 is sandwiched between a pair of casting drums and reduced. The position zero point was adjusted. In Table 1, this reduction position zero adjustment method is referred to as B. The rolling mill was controlled by controlling the rolling position of the cylinders on the left and right of the rolling mill so that the rolling force of the rolling mill was the same on the left and right.
[0108]
　In Comparative Example 2, as a method of adjusting the reduction position zero point of the casting drum, as in Example 2, a plate shorter than the drum barrel length of the casting drum as shown in FIG. 9 is sandwiched between a pair of casting drums and reduced. The position zero point was adjusted. In Table 1, this reduction position zero adjustment method is referred to as B. The rolling mill was controlled by controlling the rolling mills on the left and right cylinders so that the rolling mills were in the same rolling position on the left and right.
[0109]
　In the slabs according to Examples 1 to 3 and Comparative Examples 1 and 2, the actually measured plate thickness at the stationary portion on the entrance side of the rolling mill is 1.760 mm at the end of the drive side DS, and the work side. The plate thickness at the end of the WS was 1.820 mm, and the wedge (wedge amount) was -60 μm. The wedge ratio to the plate thickness of the slab on the entry side was -3.35%. Hereinafter, the results of manufacturing slabs using each control method will be described.
[0110]
　In Example 1, the plate thickness at both ends on the rolling mill entry side was estimated using the above formula 1, and the plate thickness at both ends on the rolling mill exit side was estimated using the above formula 2. The rolling mill was controlled based on these estimated plate thicknesses. The measured values ​​of the slab on the exit side of the rolling mill are that the plate thickness at the end of the drive side DS on the exit side of the rolling mill is 1.232 mm, the plate thickness at the end of the work side WS is 1.287 mm, and the wedge. Was -55 μm. The wedge ratio to the plate thickness of the slab on the exit side was -4.35%. From this, the difference in wedge ratio was 0.99%. The amount of meandering in the rolling mill was about 20 mm at the maximum, and rolling could be performed from the tip end portion to the tail end portion of the slab S without any problem.
[0111]
　In Example 2, the plate thickness at both ends on the rolling mill entry side was estimated using the above formula 1, and the plate thickness at both ends on the rolling mill exit side was estimated using the above formula 2. The rolling mill was controlled based on these estimated plate thicknesses. The measured values ​​of the slab on the exit side of the rolling mill are that the plate thickness at the end of the drive side DS on the exit side of the rolling mill is 1.243 mm, the plate thickness at the end of the work side WS is 1.259 mm, and the wedge. Was -17 μm. The wedge ratio to the plate thickness of the slab on the exit side was −1.35%. From this, the difference in wedge ratio was 2.00%. The amount of meandering in the rolling mill was about 70 mm at the maximum, and rolling could be performed from the tip end portion to the tail end portion of the slab S without any problem.
[0112]
　In Example 3, the plate thickness at both ends on the rolling mill entry side is estimated using the above formula 1, and the plate thickness at both ends on the rolling mill exit side is measured by a plate thickness gauge and is estimated to be the plate thickness. The rolling mill was controlled based on the measured plate thickness. The measured values ​​of the slab on the exit side of the rolling mill are that the plate thickness at the end of the drive side DS on the exit side of the rolling mill is 1.232 mm, the plate thickness at the end of the work side WS is 1.284 mm, and the wedge. Was -52 μm. The wedge ratio to the plate thickness of the slab on the exit side was -4.13%. From this, the difference in wedge ratio was 0.78%. The amount of meandering in the rolling mill was about 15 mm at the maximum, and rolling could be performed from the tip end portion to the tail end portion of the slab S without any problem.
[0113]
　In Comparative Example 1, the measured values ​​of the slabs on the exit side of the rolling mill were such that the plate thickness at the end of the drive side DS on the exit side of the rolling mill was 1.285 mm, and the plate thickness at the end of the work side WS was 1. It was 238 mm and the wedge was 47 μm. The wedge ratio to the plate thickness of the slab on the exit side was 3.74%. From this, the difference in wedge ratio was 7.09%. The amount of meandering in the rolling mill was about 200 mm at the maximum, and narrowing occurred at the tail end of the slab S.
[0114]
　In Comparative Example 2, the measured values ​​of the slabs on the exit side of the rolling mill were such that the plate thickness at the end of the drive side DS on the exit side of the rolling mill was 1.285 mm, and the plate thickness at the end of the work side WS was 1. It was 219 mm and the wedge was 65 μm. The wedge ratio to the plate thickness of the slab on the exit side was 5.22%. From this, the difference in wedge ratio was 8.58%. The amount of meandering in the rolling mill was about 250 mm at the maximum, and the slab contacted and broke in the side guide on the side of the rolling mill, resulting in fracture.
[0115]
　From the above, in the production of slabs using the slab manufacturing equipment as described above, the deformation characteristics of the housing that supports the casting drum and the deformation characteristics of the rolling system that rolls down the casting drum acquired before the start of casting of the slabs. The plate thickness of the slab S is estimated using the rolling system deformation characteristics of the cast drum housing, which indicates By adjusting the position, meandering in the rolling mill can be reduced and plate passing trouble can be reduced.
[0116]
[table 1]

[0117]
　Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that a person having ordinary knowledge in the field of technology to which the present invention belongs can come up with various modifications or modifications within the scope of the technical ideas described in the claims. , These are also naturally understood to belong to the technical scope of the present invention.
Industrial applicability
[0118]
　INDUSTRIAL APPLICABILITY The present invention can further reduce meandering in a rolling mill and reduce plate-passing troubles when manufacturing slabs in a continuous casting facility having a twin-drum type continuous casting apparatus and a rolling mill. High industrial applicability.
Description of the sign
[0119]
　10 Continuous casting device
　11 1st casting drum
　12 2nd casting drum
　20 1st pinch roll
　30 Roller
　40 2nd pinch roll
　50 Winding device
　100 Control device
　110 Serpentine meter
　200 Control device
　210 Plate thickness meter
　111, 112 Bearing box ( Or chock)
The scope of the claims
[Claim 1]
　A slab is formed using a twin-drum continuous casting device that solidifies molten metal with a pair of rotating casting drums to cast slabs, and a rolling mill that rolls the cast slabs with a pair of work rolls. In the method for manufacturing a slab to be manufactured
　, a cast drum housing rolling system that shows the deformation characteristics of the housing that supports the casting drum and the deformation characteristics of the rolling system that rolls the casting drum, which are acquired before the start of casting of the slab. Using the deformation characteristics, the estimated plate thickness at both ends of the slab in the width direction is calculated from the following
　formula 1, and based on the estimated plate thickness calculated from the formula 1, at the entrance side of the rolling mill. The difference in plate thickness between
　both ends on the exit side of the rolling mill is calculated by calculating the entrance wedge ratio, which indicates the ratio between the inlet side wedge, which is the difference in plate thickness at both ends, and the inlet plate thickness of the slab. The exit side wedge ratio, which indicates the ratio between the outlet side wedge and the exit side plate thickness of the slab, is calculated so
　that the difference between the entrance side wedge ratio and the exit side wedge ratio is within a predetermined range. A method for manufacturing a slab that adjusts the rolling position of the rolling mill.
(Estimated plate thickness on the input side of the rolling mill) = (Casting cylinder rolling position)
　　　　　+ (Casting drum elastic deformation)
　　　　　+ (Casting drum housing rolling system deformation)
　　　　　+ (Casting drum drum profile)
　　　　　-( Casting position zero point adjustment ) Elastic deformation of the casting drum in) ... Equation 1
[Claim 2]
　The slab according to claim 1, wherein the slab thickness used for calculating the siding wedge ratio is estimated by the following formula 2 using the position information in the width direction of the slab directly under the roll bite. Manufacturing method.
(Estimated plate thickness on the exit side of the rolling mill) = (Rolling cylinder rolling position)
　　　　　+ (Work roll elastic deformation)
　　　　　+ (Rolling machine housing rolling system deformation)
　　　　　+ (Work roll roll profile)
　　　　　-( Rolling position zero point adjustment ) Elastic deformation of the work roll in) ... Equation 2
[Claim 3]
　The method for manufacturing a slab according to claim 1, wherein the outside plate thickness used for calculating the outside wedge ratio is an actually measured value of the plate thickness of the slab on the outside of the rolling mill.
[Claim 4]
　The casting drum housing reduction system deformation characteristic is that the pair of side dams provided at the widthwise end of the casting drum is opened, and the plate width is longer than the drum length of the casting drum between the casting drums and the plate thickness is increased. The production of the slab according to any one of claims 1 to 3, which is obtained based on the reduction position and load of the casting cylinder obtained by performing tightening with a uniform plate sandwiched between the two. Method.
[Claim 5]
　The reduction position zero adjustment of the casting drum is performed by opening a pair of side dams provided at the widthwise end portions of the casting drum so that the plate width is longer than the drum length of the casting drum between the casting drums. The method for producing a slab according to any one of claims 1 to 4, which is performed with a plate having a uniform thickness sandwiched between them.
[Claim 6]
　Manufacture of slabs comprising a twin-drum continuous casting apparatus for solidifying molten metal with a pair of rotating casting drums to cast slabs, and a rolling mill for rolling the cast slabs with a pair of work rolls. in equipment, and a control device for adjusting the rolling positions of the rolling mill,
　the control device,
　pressure of the casting drum and deformation characteristics of the housing for supporting the casting drum which is acquired before the start of casting of the slab A plate thickness calculation unit that calculates the estimated plate thickness at both ends of the slab in the width direction from the following equation 1 using the rolling system deformation characteristics of the cast drum housing that indicates the deformation characteristics of the rolling system, and the estimated plate. Using the thickness, the entry-side wedge ratio, which indicates the ratio between the entry-side wedge, which is the difference in plate thickness between both ends on the entry side of the
　rolling mill , and the entry-side plate thickness of the slab, is obtained. A ratio calculation unit for obtaining the exit side wedge ratio, which is the difference between the plate thicknesses at both ends on the outlet side, and the exit side wedge ratio, which indicates the ratio between the outlet side plate thickness of the slab, and the
　entry side wedge ratio and the above. A control device including a control unit for adjusting the rolling position of the rolling mill so that the difference from the exit side wedge ratio is within a predetermined range.
(Estimated plate thickness on the input side of the rolling mill) = (Casting cylinder rolling position)
　　　　　+ (Casting drum elastic deformation)
　　　　　+ (Casting drum housing rolling system deformation)
　　　　　+ (Casting drum drum profile)
　　　　　-( Casting position zero point adjustment ) Elastic deformation of the casting drum in) ... Equation 1