KR100263779B1 - Method and device for pre-rolling control of slabs with thin plate structure - Google Patents

Abstract

The pre-rolling operation is carried out with a plurality of roll pairs 14-16 coupled together in one or more pre-rolling assemblies 10 and the first assembly 10 is placed at the bottom of the foot roll 12 of the mold 10. And the displacement type roll 16 is included in the roll pair 14-16. The pair of rolls 14-16 are combined with the pressure converting means 18 and the hydraulic capsule means 17. And the pressure converting means 18 and 24 are coupled with the data processing unit 21, and the first roll pair 14-16 has exited the mold 11 having the thin plate solidification surface 31 ( 20). This method removes the liquid core by rolling so that the reduction in the thickness of the slab 20 leaving the last rolled roll pair 14-16 is greater than 10%, and refines the central solidification structure in contact with the zone of the two-phase condition. Minimize separation. The apparatus for carrying out the pre-rolling control of the thin slab according to the present invention comprises means for measuring the liquid container temperature in tundish 25a, slab 20 temperature observing means 25b and also slab 20 speed observing means. And 26 means for observing whether the liquid cone is present.

Description

Method and device for pre-rolling control of slabs with thin plate structure

1 shows one side of an assembly in accordance with the present invention for pre-rolling slabs of sheet structure produced by a curved continuous casting operation.

2 and 3 illustrate pre-rolling rulers having two different shapes.

4 (a) and 4 (b) show two positions forming the pre-rolled assemblies of FIG.

5 shows a two-phase region formed when following the present invention.

* Explanation of symbols for main parts of the drawings

10: pre-rolled assembly 11: mold

12: footer 14,114,214: roller

15: load cell 19: servo valve

20: slab 21: data processing control unit

25a, 25b: temperature measuring means 26: speed measuring means

29 cooling means 30 spray nozzle

The present invention relates to a control method and a control device for pre-rolling a slab of a sheet structure leaving a continuous casting factory.

More precisely, the present invention is carried out on slabs leaving a mold for continuous casting of thin slabs, and is located directly downstream of the foot rolls of the mold and It relates to a method and also to a device suitable for applying the method.

Laminated slabs are slabs with a width of 800 mm to 2500 mm or more and a thickness of 25 mm to 90 mm.

The invention is advantageously applied to slabs having a final thickness of 30 mm to 60 mm at the exit of the continuous casting machine.

The present invention is also applicable to continuous casting operations of billets consisting of circles, squares, rectangles, and the like.

The invention can be applied to straight or curved continuous casting plants.

BACKGROUND OF THE INVENTION A prerolling method is known in which a slab of thin plate structure undergoes a prerolling action in an area located away from a foot roller.

According to the prior art disclosed in documents JP-A-130759, US-A-3,891,025, US-A-4,056,140 and US-A-4,134,440, the pre-rolling operation is performed at the position of the slab. However, liquid cores are rarely present, and the surface of the slab is already thick, so the pre-rolling operation is not satisfactory because the slab cannot be easily deformed.

In addition, one side of the slab is connected to the other surface of the slab by columnar solidification elements at the intermediate positions of the edges. By both sides and columnar solidification elements having a constant solidification thickness, a strong resistance to the thickness change of the slab is provided.

Therefore, the pre-rolling operation by the method according to the prior art has a very limited and poor effect, the result is negative.

In addition, the pre-rolling operation by the method according to the prior art is the purpose of performing peripheral and superficial work, the main work to reduce the thickness of the slab is carried out by a rolling train located downstream.

Also in the pre-rolling assembly according to the prior art, only some of the rollers in the pair are controlled, in order to check the parameters related to the pre-rolling, when the roller is referred (see document JP-A-130759). They are controlled in different individual ways. Thus, the method of operation cannot be adjusted according to specific requirements, and the method of operation is in some respects very arbitrary.

Also known are pre-rolled assemblies which consist of a mechanical fixation system in which the casting process is initially preconditioned. The prerolled rollers and the prerolled assemblies are connected, or the pressure belt assemblies and the prerolled assemblies are connected in series or divided into rollers of several sectors or groups.

However, the adjustment action by the system according to the prior art is not good, and the preliminary rolling operation of the moving distance or target value continuously related to the actual preliminary rolling conditions and continuously controlled is impossible. Yet the systems cannot be operated in the presence of liquid cores and very small surface thicknesses.

Although the core length of the liquid phase is reduced by the mechanical control action by the prior art and thus a good quality is ensured, the operation of the system is considerably limited by the problems related to the start-up and stop transition states of the system. The yield of can not be excellent.

According to the prior art, reflow of the liquid metal in the induction and stop state of the liquid material during the start-up operation is not prevented, and as a result, the defective rate is high.

In order to overcome the shortcomings of the prior art and to provide further advantages, the applicant of the present invention has tested and studied the present invention.

Pre-rolling of the present invention by pre-rolling assembly disclosed in document EP-A-0 539 784, which is incorporated herein by reference and filed Oct. 20, 1992, filed on US patent application Ser. No. 07 / 963,734. The method can be carried out advantageously.

It is an object of the present invention to preroll control or reduce the thickness of the slab leaving the crystallizer in order to produce a smaller thickness slab at the end of the casting machine.

In view of the main advantages of pre-rolling control to reduce liquid cores, essentially thinner slabs (with a thickness of 30-6 mm) at the exit of the casting machine can be produced by thicker crystallizers of thickness, ie After the pre-rolling control action, the smaller side width, which is formed in the longitudinal passage of the crystallization apparatus, has a larger final thickness of the slab.

The pre-rolling control action improves the hydrodynamic behavior of the liquid metal in the crystallization apparatus of the mold. It also improves the life of the nozzles that are assembled and submerged on the tundish and improves the behavior during melting of the powder placed on top of the liquid metal in the mold.

In addition, the solidification structure of the metal is refined and segregation is removed at the center of the slab.

In both cases, the soft portion has to be reduced by the continuously controlled slab thickness reduction, and the constituent parts of the slab in which the soft portion is reduced are formed conical.

The length of the conical component is about 0.8 to 7 meters or preferably 3.8 to 6.3. At the end of the region formed by the rollers downstream of the crystallization apparatus and located next to the footer, the length of the circular component is longer.

When the thickness reduction is made by the conical parts, the length of the conical part changes according to the following metallic factors.

Coagulation is effected differently by different types of steel. The coagulation of low carbon steels (with a carbon content of 0.10% or less) is characterized by a columnar structure, short grain length, small discontinuities, short lengths of two-phase regions, and compactness. The solidification surface moves forward in a compact state.

High carbon steel (with a carbon content of 0.70% or more) has a columnar structure and features long crystal grains, and the solidification surface has a large discontinuity and a grid of large dendrites. Forming, separate liquid steel regions exist between the dentites. In this case, the size of the biphasic region is quite large.

(The moment of contact between the two solidified surfaces formed on the upper and lower sides of the slab is a very important moment that determines the internal and final quality of the slab. In fact, the effect of expanding (the slab between the two pairs of embedded and facing rollers The liquid in the separated state is pumped in. The expansion effect is limited but cannot be sufficiently removed.

When the slab is opened due to the expansion effect, the liquid between the dendrites is sucked back toward the centerline of the slab by the cavity between the dendrites.

If the slab is closed as the slab passes through the next pair of rollers, the liquid is pumped in the opposite direction from the centerline to the cavities between the dendrites.

Due to the alternating pumping effect, positive or negative segregation regions are formed at the centerline of the slab.

In order to prevent continuous back and forth flow of the separated liquid, it is necessary to close the passages between the dendrites and the passages between the particles by densifying the tissue at the solidification surface.

By constructing a conical section of reduced size and rolling the slab lightly, the two halves that make up the slab are compressed against each other, so that the sealing action can be achieved.

Due to the different sizes of the two-phase regions formed in the various types of steel, the compression is effected so that the two solidifying surfaces penetrate differently with respect to each other depending on the shape of the steel.

Solid composition ratios are constant (at a value of about 90-95%) and steels with a low carbon content and shorter lengths in the two-phase zone must penetrate up to several millimeters against each other to a depth where the space size between the dendrites is substantially zero. .

Steels with a high content of carbon and long two-phase regions must be infiltrated with each other to a depth where the solid composition ratio is smaller (up to 70%) and the space size between the dendrites is considerably larger.

The best solid composition ratio at the end of the reduction action therefore depends on the shape of the steel and, as a result, depending on the metallurgical factors, the solid composition ratio can increase or decrease from 2% to 2.5%.

Carbon (C) Content (%) Solid Composition (%)

<0.20 95

0.20-0.40 90

0.40-0.70 80

> 0.70 70

To obtain good internal quality Within the region where the solid composition ratio is the best, the end of the conical section where the thickness of the slab is to be reduced must be formed.

For steel having a solid composition ratio of 70% according to the carbon (C) content, it is preferable that a slab with a thickness of 30 mm, starting at a single side of 50 mm from the mold crystallizer, be formed at the end of the casting machine. Suppose

The reduction performed is 20 mm (since 50 mm-30 mm).

Determine the solidification distribution of the slab in the current casting state, and when there is a 70% solid composition ratio at a distance of 15 mm (i.e. 1/2 of 30 mm) from the inside and the surface of the slab leaving the crystallizer, It is essential to determine the separation distance from the height of the uneven portion formed in the metal.

Assume that the distance from the uneven portion is 4 meters.

If the length of the crystallization device is 1.2 meters, the ductile partial reduction length Lsr is

Lsr = 4mm-1.2mm = 2.8meter

And the decreasing gradient (Gsr) is

Gst = (50mm-30mm) /2.8meter = 7.143mm / m

to be. In other words, a thickness of 7.143 mm is required by one meter of the slab located outside the crystallizer.

Thus, the preliminary rolling method is performed on an ON LINE solidification model that determines the exact solidification distribution of the slab based on the current casting state.

The solidification model calculates the length at which the pre-rolling takes place-the ductile partial reduction length Lsr, i.e. the required solid composition ratio at half the depth of the thickness of the slab produced and the position formed along the device.

When the length of the prerolling is determined, the reducing conical portion for forming the reducing gradient Gsr is adjusted by the rolling operation so that the end portion of the reducing action is the calculated soft portion length decreasing length Lsr.

The control action reduces the length of the conical cores in the liquid phase, minimizing segregation found in non-alloyed steels containing medium-high carbon, alloy steels containing medium-low carbon, or conventional steel. And the reduction is achieved.

When the length reduction of the conical core forming the liquid phase is controlled in the above manner, the mushroom region can be continuously reduced in contact with the liquid phase region to grow a coaxial structure that can be formed by electromagnetic disturbance.

According to another object of the present invention, the crystal formation rate is increased, thereby increasing the stable connection portion formation rate of the column structure between the surface of one side of the slab and the surface of the other side of the slab.

In the method according to the invention, the connecting portions of the columnar structure are formed in a compacted state due to the prerolling action of the prerolled assembly so that the connecting portions have a typical arrangement and are produced compactly.

As a result, products leaving the continuous casting factory are reached with more compactness, smaller thickness and better smoothing in the rolling line.

If the length of the cone, which forms the liquid phase as a function of the main casting parameters (including speed, superheat inside the tundish, the second cooling flow of the mold and steel grade) is dynamically controlled, Start and stop operations, either last or due to an accident, can optimize transition periods and reduce scrap.

In addition, according to the method of the present invention, it is possible to optimize the working state of the lubricated powder (such as the larger melt surface, the regularity of the powder coating formed on the liquid steel), the superheating of the steel and the increase of the turbulence stability and the uneven part stability. Regarding the surface quality in which downward flow is optimized in the mold, casting is advantageously performed in a mold having a portion having a thickness greater than that of the final portion, and a submerged nozzle having a larger cross section is more durable. Available.

Given the same number of rolling units, the outflow cross section of the slab can be reduced by the prerolling method.

According to the present invention, when a continuous casting operation is performed in a curved shape, it is connectable with pre-rolling load cells located on an outer curved side, and the pressure of the rollers applied to the slab of a thin plate structure Controlled by them.

Pre-rolling rollers located on the inner curve side are connected with a hydraulic cylinder of the type disclosed in, for example, document EP-0 444 420, replacing load cells for rollers located on the outer curve side. The prerolling rollers may be connected to the load cells.

The rolling pressure can be controlled by a pressure transducer configured on each hydraulic cylinder.

According to the invention, several pairs of rollers are arranged in one or two or more groups forming a prerolled assembly. Each prerolled assembly includes a stationary portion and a moving portion. For example, while the outer curved side includes stationary rollers, movable rollers are configured on the inner curved side, and in fact, the outer curved side and the inner curved side may be configured oppositely.

According to one embodiment, stops and moving portions interacting with the moving and stopping portions of each opposite side may be included in the inner curve side and the outer curve side.

According to Embodiment 1 of the present invention, each pair of rollers is connected with one position changer, and the distance between the rollers facing each other is measured by the position changer.

According to Embodiment 2 of the present invention, each group of rollers forming a prerolled assembly and paired with each other comprises two transducers for measuring the position of the prerolled assembly, the transducers upstream of the prerolled assembly and Located at the downstream end, respectively, the distance between the facing rollers is measured.

According to a variant of embodiment 2 above, each pair of rollers is also connected with one position changer. By means of the position converter, it is possible to construct a rolling passage between the pair of rollers in the prerolled assembly. According to certain requirements, the passages are configurable such that the sides of the passages are parallel or gradually narrower.

In addition, when each pair of rollers is connected to one position changer, each pair of rollers can be positioned at a required position, thereby making it possible to construct a preliminary rolling passage having all special types of longitudinal cross sections.

Velocity measuring means for measuring the speed of pressure transducers, position transducers and slabs, cooling measuring instruments, temperature measuring means for measuring the temperature of the molten metal, whether or not preliminary one or more pre-rolled assemblies are applied The entire system is controlled by a data processing control unit which receives signals from the temperature measuring means for measuring the temperature of the slab leaving the thin plate structure.

According to the present invention, there may also be included temperature measuring means for measuring the temperature of the slab at intermediate positions within the region in which the pre-rolled assembly operates and for transmitting a signal to the data processing control unit.

In addition, in the pre-rolled assembly according to the present invention, in order to check the presence or absence of a liquid part in the slab and to accurately seal the conical core having a liquid phase, for example, a sonar type measuring device may be configured.

The data processing control unit may form part of another general data processing control unit or may be connected to the general data processing control unit, and the data processing control unit may process all the parameters and may be embedded or input properly in an internal file. The prerolling parameters are compared with the parameters, and the data processing control unit provides adjustments suitable for several pairs of rollers.

The data processing control unit is also connectable to an auxiliary data input unit, and in addition to recording all the values provided by the measuring instruments, the data input unit can display or print a numerical change over time in a data bank. ) Are entered.

In the above description, the rollers refer to rollers arranged in a continuous row, separated into a plurality of fan-shaped parts, separated into belt parts, and included in all systems of the prior art.

According to the method according to the invention, the assembly or the entire preroll assembly of the rollers following a single roller or another preroll assembly at a time is adjusted. Coordination can be increased logarithmically.

By the pre-rolling method according to the invention, the thickness of the slab can be reduced by about 10% to 50%. The thickness reduction is made within a distance of 0.8 meters to 7 meters or 1.2 meters to 1.8 meters.

The thickness reduction of the slab may be made gradually according to a predetermined value.

According to a variant, the thickness reduction of the slab is carried out in several steps by means of the final finishing where the thickness is reduced gradually.

According to a variant, the pre-rolled assembly of the invention is connected with means for secondary cooling of the slab, for example the means consisting of a plurality of spray nozzles.

By the data processing control unit or the general data processing control unit, the flow rate and the transfer pressure of the spray nozzle are advantageously adjusted, so that the state of the slab is continuously controlled.

By means of measuring means for measuring the temperature of the slab, the spray nozzles can be controlled, which are arranged along the pre-rolled assembly.

According to another variant, for example at least one descaling device disclosed in patent application EP-93110927.6 filed by the applicant can be connected with the prerolled assembly of the invention. By the descaling device provided upstream of the first pre-rolled assembly, the slab of thin plate structure can be produced with excellent surface quality for special continuous process use.

According to a variant, a plurality of descaling devices are included between the pair of prerolling rollers.

According to another variant, descaling devices are constructed between each pair of preroll rollers.

According to another variant, the rollers are cooled internally so as to prevent the scale removed from the surface of the slabs of the laminated structure from adhering to the surface of the roller, especially as long as the descaling device is constructed between the pair of rollers. .

The accompanying drawings are provided as non-limiting examples and illustrate preferred embodiments of the present invention.

Referring to the drawings, the pre-rolling method of the present invention is performed by at least one pre-rolled assembly 10 composed of a plurality of paired rollers 1,416.

Referring to FIG. 1, only one of the foot rolls 12 and the preroll assembly 10 in combination with a mold 11 is shown and another preroll assembly ( 10) is only partially installed immediately downstream.

The prerolled assembly 10 is installed immediately downstream of the mold 10 at a distance of about 0.5 meters.

When the pair of rollers 14, 16 are arranged in continuous rows or divided into conical shapes, divided into two or three or more groups (see Figure 2), or (see Figure 3), ) It may be composed of a belt structure or other forms known in the art.

In the illustrated embodiment, the outer curved side surface 13 of the prerolled assembly 10 consists of a portion or frame in a stationary or stationary state, while the inner curved side surface of the prerolled assembly 10 ( 22) consists of a movable portion or frame.

The rollers 14, 114, 214 and the other rollers configured on the outer curved side surface 13 can be connected to at least one load cell 15 in one or a group, and are preliminary by the load cell 15. The signal is transmitted to the data processing control unit 21 of the rolled assembly.

In the embodiment shown in FIG. 1, the rollers 16, 116, 216 and other rollers configured on the inner curved side 22 are connectable in one or a group with at least one hydraulic cylinder 17.

Each hydraulic cylinder 17 controlled by the servovalve 19 is connected with a pressure transducer 18. The servo valve 19 is controlled by the data processing control unit 21 of the preliminary rolling assembly.

In this embodiment, each pair of rollers 14, 16 are connected with respective position transducers 24, and each pre-rolled assembly is connected with two position transducers 124a, 124b, the position transducers And adjust the position of the pre-rolled assembly, respectively arranged in the pre-rolled assembly 10 and arranged as an upstream position transducer 124a and a downstream position transducer 124b.

The upstream position transducer 124a and downstream position transducer 124b for adjusting the position of the prerolled assembly are connected to the prerolled assembly 10, while between the pair of rollers 14, 16 Cloud movement paths of walls with parallel structures (in FIG. 4 (a)) or concentrated structures (in FIG. 4 (b)) can be constructed.

In this embodiment, position transducers 124a and 124b are provided between the inner curved side surface 22 and the movable outer curved side surface 13 which are constructed and movable in the preliminary rolling assembly 10.

According to a variant not shown in the drawings of the present invention, the position transducers 124a and 124b may be connected only to the inner curved side surface 22 that is configured and movable in the pre-rolled assembly 10.

Each pressure transducer 18, each position transducer 24 and each position transducer 124a, 124b transmits its signals to the data processing control unit 21 and receives control signals and confirmation signals.

At the beginning of the rolling process, parameters relating to the preliminary rolling operations to be performed and to the dimensions of the cast material form and the slab 20 to be laminated are set and entered into the data control processing unit 21.

The data control processing unit 21 pre-arranges the pair of rollers 14 and 16, the rollers 114 and 116 and the rollers 214 and 216, and also when the casting operation is started and the starter bar is separated, The pair of rollers 14 and 16, the rollers 114 and 116 and the rollers 214 and 216 are controlled and adjusted one by one to carry out necessary pre-rolling operations.

According to the present invention, the temperature measuring means for controlling the temperature of the molten metal and control the metal temperature in the tundish to adjust and control the pre-rolling operation to reduce the slab 20 to the required thickness ( 25a), the temperature measuring means 25b for controlling the temperature of the slab 20 flowing out of the mold 11 and forming a thin plate structure, and the speed measuring means 26 for controlling the speed of the slab 20 control data. It is connected to the processing unit 21.

The signals of the temperature measuring means 25a, the temperature measuring means 25b and the speed measuring means 26 are transmitted to the data control processing unit 21, and dynamically in accordance with the speed of the slab 20 in the preliminary rolling method. It can be controlled, and also the transition states of the starting and stopping states are managed more accurately.

According to a variant, in order to control the slab 20 to a preset temperature, a plurality of temperature measuring means 25b with respect to the temperature of the slab 20 along the prerolled assembly 10 may be auxiliary.

In this case, the data control processing unit 21 is connected to a data input unit 27 for inputting and storing data tada and a general data control processing unit 121.

For example, the data control processing unit 21 for controlling the adjustment state based on a control program set by a machine operating factor such as the reciprocating position of the pair of rollers 14 and 15 constituted in the prerolled assembly 10. Alternatively, the state of the general data control processing unit 121 is determined.

By the adjustment and control system, the thickness of the slab 20 can be reduced from 10% to 50%.

According to an embodiment of the invention, the cooling means 29 for secondary cooling of the slab 20 is connected with the pre-rolled assembly 10, in which case the cooling means 29 comprises a plurality of spray nozzles 30. )

By the data control processing unit 21 or the general data control processing unit 121, the flow rate and the transfer pressure of the spray nozzles 30 are advantageously controlled, so that the state of the slab 20 can be continuously controlled. .

By the temperature measuring means 25b for controlling the temperature of the slab 20 having a thin plate structure, the spray nozzles 30 arranged along the pre-rolled assembly 10 may be controlled.

According to the invention, at least one cooling means 29, for example in the form of a sonar device, in order to identify the sealing point (kissing point) of the core in the form of a cone and liquid state inside the slab 20. ) Is connected to the pre-rolled assembly (10).

In order to control the cooling means 29, it is advantageous for one or more cooling measuring instruments 28 to be connected with the general data control processing unit 121.

For example, according to the preliminary rolling method according to the present invention, the thickness of the slab 20, which moves at a preferred distance of 0.8 meters to 2.5 meters or 1.2 meters to 1.5 meters and moves at a casting speed of 4.5 meters per minute, is 70 mm to It can be reduced from 75mm to 50mm.

According to a program set in the data control processing unit 21 or the general data control processing unit 121, the slab thickness is gradually reduced by a predetermined value, or stepwise by the final finishing portion where the thickness reduction is gradually performed. Is reduced.

In this embodiment, a preliminary device according to the invention is provided by a descaling device 23 inserted downstream of the footers 12 to produce a slab 20 of sheet structure with good surface quality. The oxide layer formed on the surface of the slab 20 located immediately upstream of the rolled assembly 10 is removed.

According to an embodiment, one or more descaling devices 23 may be installed between a pair of rollers 14 and 16 and other pairs of rollers.

According to a further embodiment, several pairs of rollers 14, 16 connected to the descaling devices 23 internally carry the prerolled rollers 14, 16, for example internal circulation of the cooling fluid. Means for cooling. According to the above configuration, the scale removed from the surface of the slab 20 by the descaling devices 23 is prevented from adhering to the surface of the rollers due to the high temperature, so that frequent operation for keeping the operating surface of the rollers completely smooth is possible. Maintenance and correction work is unnecessary.

Referring to FIG. 5, a method is provided in which the surface 31 and the two-phase region 32 of the slab are gradually increased, and the surface is formed due to the pressure exerted by the prerolled assembly 10, Gradually reinforced, the surface is sealed before the slab 20 leaves the preroll assembly 10 such that the cone or pool portion of the core 33 is enclosed within the preroll assembly 10. do.

Claims (34)

The pre-rolling operation is performed by the rollers 14 and 16 which are grouped with each other in one or two or more pre-rolling assemblies 10 and form a pair, and among the pre-rolling assemblies 10, a first A prerolled assembly is located immediately downstream of the footers 12 of the mold 11, wherein one or more movable rollers 16 are included in the pair of rollers 14, 16, and the pair of rollers ( 14 and 16 are connected to the pressure transducer 18 and the hydraulic cylinder 17, the position transducer 24 is included, and the pressure transducer 18 and the position transducer 24 are connected to the data control processing unit 21. In which the data control processing unit comprises a control and adjustment program, and the slab 20 just discharged from the mold 11 with a solidified surface 31 is provided with at least first pairs of rollers 14, 16. Pre-rolling agent of slabs 20 processed by and discharged from continuous casting factory and forming a thin plate structure In the method, the temperature measuring means 25a for measuring the solution temperature inside the tundish, the speed measuring means 26 for measuring the casting speed, and the slab 20 move away from the mold 11 and the slab 20 is moved. Temperature measuring means 25b, which is functionally related to the temperature of the slab 20, is connected with the data control processing unit 21 while the prerolled assembly 10 is located in the prerolled assembly 10, and removes the liquid core 33. , Slab 20 leaving the last pair of rollers 14 and 16 where prerolling takes place, in order to contact the two-phase regions 32 so that the central solidification structure is refined and the segregation and porosity of the central part is minimized. Based on the adjustment and control program, the reciprocating positions of the rollers 16 constituting at least a portion of the pair of rollers 14 and 16 are controlled so that the prerolling action is performed while the thickness of the roller is reduced by more than 10%. Made by the processing unit 21 Pre-rolling control method of the slab forming a thin plate structure, characterized in that the air. 2. The preliminary preparation of slabs having a thin plate structure according to claim 1, wherein dynamic pre-rolling control is performed by the data control processing unit 21, and control of the transition time associated with starting and stopping the casting operation is optimized. Rolling control method. The method according to claim 1, wherein the thickness of the slab (20) is reduced within a distance of 0.8 to 7 meters from the outlet of the mold (11). The method according to claim 1, wherein the thickness of the slab (20) is gradually reduced according to a predetermined value. The method according to claim 1, wherein the thickness of the slab (20) is gradually reduced by a final step in which a final reduction action is carried out gradually. The method according to claim 1, wherein the slab (20) undergoes a descaling operation before the slab (20) enters at least the first rolled assembly (10). The method of claim 1, wherein the sealing point of the core located in the slab 20 to move forward is controlled by the cooling measuring device 28 for measuring the sealing point of the core 33 in the liquid state, the cooling meter 28 is the data Pre-rolling control method of the slab forming a thin plate structure, characterized in that connected to the control processing unit (21). The flow rate of the spray nozzle 30 with respect to the slab 20 is controlled by the data control processing unit 21, which is adjusted by the temperature measuring means 25b for measuring the temperature of the slab 20. Pre-rolling control method of the slab forming a thin plate structure, characterized in that. The method according to claim 1, wherein at least the pressure of the spray nozzle (30) is controlled by a data control processing unit (21) for adjusting the temperature of the slab (20). Pre-rolling is performed by a plurality of pairs of rollers 14, 16 in one or more pre-rolling assemblies 10, and directly downstream of the footers 12 of the mold 11. 1 The rolled assembly 10 is located, wherein one or more movable rollers 16 are included in the rollers, and the pair of rollers 14, 16 are connected to the pressure transducer 18, the hydraulic cylinder 17, and the like. The position transducer 24 is connected, the pressure transducer 18 and the position transducer 24 are connected with the data control processing unit 21, leave the mold 11, and the solidified surface 31 Pre-rolling control device of the slab (20) is processed by at least the first pair of rollers of the pair of rollers (14, 16), the slab (20) is formed from a continuous casting factory and a thin plate structure In the tundish, the temperature measuring means 25a for measuring the liquid temperature in the tundish and the speed of the slab 20 are measured. Speed measuring means (26), of forming the sheet structure, characterized in that the cooling instrument for sensing a liquid core (28) is configured slab pre-rolling control apparatus. 11. The pre-rolling control apparatus of slabs according to claim 10, characterized in that a separate position converter (24) is connected with each pair of rollers (14, 16). The slab of claim 10, wherein the position transducers 124a and 124b for measuring the position of the pre-rolled assembly 10 are connected to a plurality of paired rollers 14 and 16. Pre-rolling control device. 11. The preliminary rolling control apparatus for slabs having a thin plate structure according to claim 10, wherein the means for controlling the pressure of the coolant delivered by the spray nozzles 30 is controlled by the data processing control unit 21. . 12. The preliminary rolling control of slabs having a thin plate structure according to claim 10, wherein at least means for controlling the flow rate of the cooling water delivered by the spray nozzles 30 is controlled by the data processing control unit 21. Device. 11. The pre-rolling control device for slabs according to claim 10, characterized in that a data input unit (27) for collecting and inputting data is configured. The pre-rolling control apparatus of slabs according to claim 10, wherein pre-rolling rollers of the pair of rollers (14, 16) are connected with cooling means therein. Located directly downstream of the footer 12 of the mold 11, adjacent to the first face of the slab 20 such that the slab 20 passing through the prerolled assembly 10 has a liquid core 33. And a plurality of rollers 14, 114, and 214, the outer curved side surface 13 having a fan shape, and the inner curved side surface 22 provided adjacent to the second surface of the slab 20 and movable in a fan shape. For the positioning of the rollers 16, 116, 216, which are arranged at the head, the inner curve side surface 22 is formed, which is composed of a plurality of rollers 16, 116, 216 connected to at least one hydraulic cylinder 17 controlled by the servovalve 19. A preliminary rolling assembly provided with one or more components and configured to pre-roll control slab (20) of sheet structure leaving the mold (11) of continuous casting function. 18. The slab of claim 17, wherein a plurality of rollers (14, 114, 214) configured at the stationary outer curved side surface (13) are connected to at least one load cell (15). Pre-rolling control device. 19. The preliminary rolling control apparatus for slabs according to claim 18, characterized in that the hydraulic cylinder (17) is connected with the pressure transducer (188) and the position transducer (24). 20. A data processing control unit (21) according to claim 19, wherein a data input unit (27) is constructed, and a data processing control unit (21) for inputting parameters relating to properties and preliminary rolling of the liquid core (33) formed in the slab (20). Pre-rolling control device of the slab discharged from the continuous casting plant and forming a thin plate structure characterized in that it is connected to the load cell (15), servo valve (19), pressure transducer (18) and position transducer (24). 18. The method according to claim 17, wherein the rollers formed on each of the outer curved side surface 13 and the inner curved side surface 22 are rollers 14 and 16 of continuous structure, and are formed from a continuous casting factory. Pre-rolling control device of slabs. 18. The method according to claim 17, wherein the rollers formed on each of the outer curved side surfaces 13 and the inner curved side surfaces 22 are rollers 114 and 116 made of separate parts, and form a thin plate structure. Pre-rolling control device of slabs. 18. The thin plate structure as claimed in claim 17, wherein the rollers formed on each of the outer curved side surfaces (13) and the inner curved side surfaces (22) support rollers (214, 216) of a crawler belt structure. Pre-rolling control device of the slab forming a. 18. The method according to claim 17, wherein the hydraulic cylinder (17) controlled by the servovalve (19) is connected with the respective rollers (16) configured on the inner side of the curve. Pre-rolling control device of slabs. 18. The hydraulic cylinder according to claim 17, wherein the rollers of the inner curved side surface 22 are arranged inside the rollers 116 that make up the group, and the rollers 116 that make up each group are controlled by the servovalve 19. 17) pre-rolling control device of the slab discharged from the continuous casting factory characterized in that it is connected to the sheet structure. A thin plate leaving the mold 11 of continuous casting function, comprising the molds 12, having a continuous casting mold 11 for producing a slab 20 of thin plate structure with liquid cores 33. It is composed of a pre-rolled assembly 10 for pre-rolling control of the slab 20 of the structure, so that the slab 20 passing through the pre-rolled assembly 10 has a liquid core 33, the pre-rolled The assembly 10 is located immediately downstream of the controllers 12 and is provided adjacent to the first face of the slab 20 and consists of a plurality of rollers 14, 114 and 214 and has a fan-shaped outer curved side surface ( 13) and controlled by the servovalve 19 for positioning of the rollers 16, 116 and 216 provided adjacent to the second face of the slab 20 and configured on the inner curved side surface 22 which is movable with a fan shape. A plurality of rolls connected to at least one hydraulic cylinder (17) (16,116,216) to one or more parts to control the pre-rolling device is configured to the pre-rolling assembly comprising a curved inner side (22) is configured. 27. The preliminary rolling control device according to claim 26, wherein a plurality of rollers (14, 114, 214) formed in the stationary outer curved side surface (13) having a fan shape is connected to one or more load cells (15). 28. The core 33 of claim 27, wherein the preroll assembly 10 is positioned relative to the footer 12, and the slab 20 of the sheet structure leaving the preroll assembly 10 is not completely solidified. Preliminary rolling control device characterized in that it has a certain length including. When the slab 20 of the thin plate structure has a liquid core 33, the slab 20 of the thin plate structure is pulled out from the footer 12 formed in the mold 11 of the continuous casting function, and the slab of the thin plate structure ( 20 has a liquid core 33 and a fan-shaped outer curved side surface 13 is composed of a plurality of rollers 14, 114 and 214, and has a fan-shaped movable inner curved side 22. When positioning the rollers 16, 116, 216 of the movable inner curve side 22, a plurality of rollers 16, 116, 216 connected with one or more hydraulic cylinders 17 controlled by the servovalve 19 are continuous. A thin slab 20 drawn from a mold having a casting function passes between the pair of rollers 14 and 16 formed on the outer curved side surface 13 and the opposite inner curved side surface 22, In order to pre-roll control the slab 20 of the sheet structure having the core 33, A method of preliminary rolling control of slabs which forms a thin plate structure by positioning rollers (16, 116, 216) of the inner curved side surface (22) having a fan shape, and leaving a mold (11) of a continuous casting function including foot rollers (12). 30. The method of claim 29, wherein a plurality of rollers (14, 114, 214) configured on the outer curved side surface (13) are connected to at least one load cell (15). The length of the pre-rolled assembly 10 and the positioning action of the movable inner curve side 22 are controlled so that the thickness of the slab 20 is reduced from 10% to 50%. Pre-rolling control method of the slab forming a thin plate structure. 30. The length and movable inner curve of the preroll assembly 10 as claimed in claim 29, wherein the slab 20 of the sheet structure leaving the preroll assembly 10 comprises a core 33 which is not completely solidified. Preliminary rolling control method of slabs forming a thin plate structure, characterized in that the positioning action of the side (22) is controlled. 33. The method of claim 32, wherein the ratio of the solid composition of the slab (20) leaving the pre-rolled assembly (10) to form a thin plate structure is 67.5% to 97.5%. 33. The central core 33 of claim 32, wherein the slab 20 of the sheet structure leaving the pre-rolled assembly 10 has a two-phase state in order to refine the central solidification structure and minimize the segregation of the core. Pre-rolling control method of the slab forming a thin plate structure, characterized in that having a.