JP5742601B2 - Solidification completion position calculation method and solidification completion position calculation device - Google Patents

Description

  The present invention relates to a slab solidification completion position calculation method and a solidification completion position calculation device for calculating a solidification completion position of a slab cast in a continuous casting machine.

  Generally, in order to improve the productivity of a continuous casting machine, it is necessary to increase the casting speed. However, when the casting speed is increased, the solidification completion position (crater end position) of the slab moves from the mold meniscus position to the downstream side in the casting direction. When the solidification completion position of the slab exceeds the range of the slab support roll, bulging occurs where the slab expands due to the action of static iron pressure. Problems such as outages occur.

  From such a background, there has been proposed a technique for detecting or calculating a solidification completion position of a slab and controlling the solidification completion position of the slab within a predetermined range based on the detected or calculated solidification completion position of the slab. (See Patent Documents 1 and 2). Specifically, in Patent Document 1, a solidification completion position of a slab is detected using a sensor, and the solidification completion position of the slab is controlled within a predetermined range based on the detected solidification completion position of the slab. The technology to do is described. Further, in Patent Document 2, the solidification completion position of the slab is calculated using a slab solidification model for calculating the temperature of the slab, and the solidification of the slab is performed based on the calculated solidification completion position of the slab. A technique for controlling the completion position within a predetermined range is described.

JP 2008-238257 A JP-A-01-127161

  However, when detecting the solidification completion position of a slab using a sensor as in the technique described in Patent Document 1, it is necessary to dispose the sensor in the vicinity of the slab, and there is a problem in the durability of the sensor. In general, since such a sensor is expensive, it is difficult to detect the solidification completion position of the slab at low cost. On the other hand, when the solidification completion position of the slab is calculated using the solidification model of the slab as in the technique described in Patent Document 2, the solidification of the slab is performed using the sensor as described above. There is no problem that occurs when the completion position is detected.

  However, when calculating the solidification completion position of the slab using the solidification model of the slab, solidification of the slab is completed when an error occurs between the various characteristic values included in the solidification model and the actual values. The position cannot be calculated with high accuracy. In order to solve such a problem, a method of correcting the characteristic value according to the actual value by performing operations such as beating can be considered. However, since such an operation is performed offline, the characteristic value cannot be corrected online.

  For this reason, it has been expected to provide a technique capable of calculating the solidification completion position of the slab with high accuracy online by making it possible to correct the characteristic value of the solidification model online.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a slab solidification completion position calculation method and a solidification completion position calculation apparatus capable of accurately calculating a slab solidification completion position online. There is to do.

  In order to solve the above-described problems and achieve the object, the solidification completion position calculation method for a slab according to the present invention calculates a solidification completion position of a slab that calculates a solidification completion position of a slab cast in a continuous casting machine. A method for calculating the volume of the slab using information on the length, width and thickness of the slab cut by a cutting machine, and dividing the weight of the slab by the calculated volume. The specific gravity of the slab corresponding to the material of the slab is calculated using the single gravity calculation step for calculating the weight of the slab per unit volume by using the specific gravity data indicating the relationship between the material and specific gravity of the slab. A thermal expansion coefficient calculating step of calculating a thermal expansion coefficient of the slab by dividing the weight of the slab per unit volume calculated in the unit weight calculating step by the calculated specific gravity, and the thermal expansion of the slab Thermal expansion showing the relationship between coefficient and temperature The slab temperature calculating step for calculating the temperature of the slab cut by the cutting machine from the thermal expansion coefficient of the slab calculated in the thermal expansion coefficient calculating step using the coefficient data, and calculated in the slab temperature calculating step. And a solidification completion position calculating step of calculating a solidification completion position of the slab using the temperature of the slab.

  In the slab solidification completion position calculating method according to the present invention, in the above invention, the slab temperature calculating step calculates a difference value between a slab temperature and a slab temperature calculated by a solidification model using a solidification model. Calculating a correction value for the temperature of the cast slab, wherein the solidification completion position calculation step corrects the temperature calculated by the solidification model using the correction value, and uses the corrected temperature. The method includes a step of calculating a solidification completion position of the slab by calculation of a solidification model.

  In order to solve the above problems and achieve the object, the slab solidification completion position calculating device according to the present invention calculates the solidification completion position of a slab that calculates the solidification completion position of a slab cast in a continuous casting machine. A specific gravity database for storing specific gravity data indicating the relationship between the material and specific gravity of the slab, and thermal expansion coefficient data indicating the relationship between the thermal expansion coefficient and the temperature of the slab. The volume of the slab was calculated using the thermal expansion coefficient database stored every time and information on the length, width, and thickness of the slab cut by the cutting machine, and the weight of the slab was calculated. A single weight calculation unit that calculates the weight of the slab per unit volume by dividing by the volume, and extracts the specific gravity of the slab corresponding to the material of the slab from the specific gravity database, and by the single weight calculation unit Calculated unit volume A thermal expansion coefficient calculation unit that calculates the thermal expansion coefficient of the slab by dividing the weight of the slab by the extracted specific gravity, and the material of the slab and the thermal expansion coefficient calculation unit from the thermal expansion coefficient database A slab temperature calculation unit for extracting a slab temperature corresponding to the calculated thermal expansion coefficient of the slab as a temperature of a slab cut by a cutting machine, and a slab extracted by the slab temperature calculation unit And a solidification completion position calculation unit for calculating a solidification completion position of the slab using the temperature of the slab.

  According to the solidification completion position calculation method and solidification completion position calculation device of the slab according to the present invention, the solidification completion position of the slab can be calculated on-line with high accuracy.

FIG. 1 is a schematic diagram showing a configuration example of a continuous casting machine to which a slab solidification completion position calculating apparatus according to an embodiment of the present invention is applied. FIG. 2 is a block diagram showing a configuration of a solidification completion position calculation system to which a slab solidification completion position calculation apparatus according to an embodiment of the present invention is applied. FIG. 3 is a diagram illustrating a configuration example of the specific gravity DB illustrated in FIG. FIG. 4 is a diagram showing a configuration example of the thermal expansion coefficient DB shown in FIG. FIG. 5 is a flowchart showing the flow of a solidification completion position calculation process according to an embodiment of the present invention.

  Hereinafter, the configuration and operation of a slab solidification completion position calculating apparatus according to an embodiment of the present invention will be described with reference to the drawings.

[Construction of continuous casting machine]
First, with reference to FIG. 1, the structure of the continuous casting machine to which the solidification completion position calculation apparatus of the slab which is one Embodiment of this invention is applied is demonstrated.

  FIG. 1 is a schematic diagram showing a configuration example of a continuous casting machine to which a slab solidification completion position calculating apparatus according to an embodiment of the present invention is applied.

  As shown in FIG. 1, the continuous casting machine has a tundish 2 into which molten steel 1 is poured from a ladle (not shown) and a molten steel 1 poured from the tundish 2 through an immersion nozzle 3 with a solidified shell on the surface. The main components are a copper mold 4 that is semi-solidified while shaping until it grows into dendrites, and a slab support roll 6 that cools the semi-solid slab 5 from the mold 4 while being drawn vertically downward. I have. The continuous casting machine includes a temperature measuring device 7 for measuring the temperature of the molten steel 1 in the tundish 2, a secondary cooling spray 8 for cooling the slab 5 by injecting cooling water onto the slab 5, and a casting A measuring roll 9 for measuring the cutting length of the piece 5, a torch (cutting machine) 10 for cutting the slab 5, and a weighing machine 11 for measuring the weight of the slab S obtained by cutting the slab 5. And.

  In such a continuous casting machine, the molten steel 1 poured into the mold 4 is cooled from the surface of the mold 4 to form a solid phase portion, and as a slab 5 having a liquid phase therein, a downstream side in the casting direction. Pulled out. The slab 5 drawn out from the mold 4 is cooled by the cooling water sprayed from the secondary cooling spray 8 and completely solidified to the center in the light pressure lower belt 12. The position completely solidified to the center is the solidification completion position of the slab 5. Then, the slab 5 that has been solidified is cut into a predetermined length by the torch 10 and is sequentially transported as a slab S to a subsequent process such as a rolling process.

[Configuration of solidification completion position calculation system]
Next, a configuration of a solidification completion position calculation system to which the slab solidification completion position calculation apparatus according to an embodiment of the present invention is applied will be described with reference to FIGS.

  FIG. 2 is a block diagram illustrating a configuration example of a solidification completion position calculation system to which a slab solidification completion position calculation apparatus according to an embodiment of the present invention is applied. FIG. 3 is a diagram illustrating a configuration example of the specific gravity DB 110 illustrated in FIG. FIG. 4 is a diagram showing a configuration example of the thermal expansion coefficient DB 120 shown in FIG.

  As shown in FIG. 2, the solidification completion position calculation system includes a solidification completion position calculation device 100, a specific gravity database (DB) 110, a thermal expansion coefficient database (DB) 120, and an output device 130. As prepared.

  The coagulation completion position calculating device 100 is electrically connected to a length measuring roll 9, a weighing machine 11, and a process computer 13. The length measuring roll 9 inputs information on the length in the casting direction of the cut slab 5 to the solidification completion position calculating device 100. The weighing machine 11 inputs information related to the weight of the cut slab 5 to the solidification completion position calculation device 100. The process computer 13 inputs information on the temperature and material of the molten steel 1, the size of the mold (width and thickness of the slab 5), and the like to the solidification completion position calculation device 100. The temperature of the molten steel 1 is measured by a thermometer 7 provided in the tundish 2.

  The coagulation completion position calculation device 100 is configured by an information processing device such as a personal computer or a workstation. The coagulation completion position calculation device 100 has a unit calculation unit 101, a thermal expansion coefficient calculation unit 102, and the like by an arithmetic processing unit such as a CPU inside the information processing apparatus executing a computer program stored in a storage unit such as a ROM. It functions as a slab temperature calculation unit 103 and a solidification completion position calculation unit 104. The functions of these units will be described later.

  As shown in FIG. 2, the specific gravity DB 110 stores specific gravity data indicating the relationship between the material (component) of the slab 5 and the specific gravity. As shown in FIG. 3, the thermal expansion coefficient DB 120 stores thermal expansion coefficient data indicating the relationship between the temperature of the slab 5 and the thermal expansion coefficient for each material of the slab 5. In the present embodiment, the solidification completion position calculation device 100, the specific gravity DB 110, and the thermal expansion DB 120 are configured separately, but they may be integrated. The output device 130 is configured by a known output device such as a display device or a printing device. The output device 130 outputs information on the temperature of the slab 5 calculated by the solidification completion position calculation device 100 and the solidification completion position.

  The solidification completion position calculation system having such a configuration calculates the solidification completion position of the slab 5 online by executing the following solidification completion position calculation processing. The operation of the solidification completion position calculation system when executing this solidification completion position calculation processing will be described below with reference to the flowchart shown in FIG.

[Coagulation completion position calculation processing]
FIG. 5 is a flowchart showing the flow of a solidification completion position calculation process according to an embodiment of the present invention. The flowchart shown in FIG. 5 is started every time the slab 5 is cut by the torch 10, and the solidification completion position calculation process proceeds to step S1.

  In the process of step S <b> 1, the unit weight calculation unit 101 includes information regarding the casting direction length of the slab 5 input from the length measuring roll 9 and information regarding the width and thickness of the slab 5 input from the process computer 5. Is used to calculate the actual volume V (= length × width × thickness) of the slab 5 cut by the torch 10. Then, the unit weight calculation unit 101 calculates the weight of the slab 5 per unit volume by dividing the value of the weight W of the slab 5 input from the weighing machine 11 by the calculated actual volume V. Thereby, the process of step S1 is completed and the coagulation completion position calculation process proceeds to the process of step S2.

  In the process of step S <b> 2, the thermal expansion coefficient calculation unit 102 acquires information on the material of the slab 5 from the process computer 13, and extracts specific gravity information corresponding to the material of the slab 5 from the specific gravity DB 110. And the thermal expansion coefficient calculation part 102 is the thermal expansion coefficient of the slab 5 cut | disconnected by the torch 10 with the value which divided the weight of the slab 5 per unit volume calculated by the process of step S1 by the extracted specific gravity. Calculate as Thereby, the process of step S2 is completed, and the solidification completion position calculation process proceeds to the process of step S3.

  In the process of step S3, the slab temperature calculation unit 103 acquires thermal expansion coefficient data corresponding to the material of the slab 5 acquired in the process of step S2 from the thermal expansion coefficient DB 120. And the slab temperature calculation part 103 reads the temperature of the slab 5 corresponding to the thermal expansion coefficient of the slab 5 calculated by the process of step S2 from the acquired thermal expansion coefficient data, and is calculated by the solidification model. A difference value between the temperature of the piece 5 and the read temperature of the slab 5 is calculated as a correction value for the temperature of the slab 5 calculated by the solidification model. Thereby, the process of step S3 is completed, and the coagulation completion position calculation process proceeds to the process of step S4.

  In the process of step S4, the solidification completion position calculation unit 104 corrects the temperature of the slab 5 calculated by the solidification model using the correction value calculated by the process of step S3, and the corrected temperature of the slab 5 is corrected. The solidification completion position of the slab 5 is calculated by solidification model calculation using The method for calculating the solidification completion position of the slab 5 is already known at the time of filing of the present invention, and therefore will not be described in detail. It can be calculated by calculating the phase line temperature and comparing the calculated liquidus and solidus temperature with the temperature of the slab 5. Thereafter, a control device (not shown) controls the interval between the support rolls installed in the light pressure lower belt 12 based on the calculated solidification completion position of the slab 5, for example, thereby determining the solidification completion position of the slab 5 in a predetermined manner. Control to be within range. Thereby, the process of step S4 is completed and a series of coagulation completion position calculation processes are complete | finished.

  As is clear from the above description, in the solidification completion position calculation process that is one embodiment of the present invention, the unit weight calculation unit 101 relates to the length, width, and thickness of the slab 5 cut by the cutting machine. The volume of the slab 5 is calculated using the information, and the weight of the slab 5 per unit volume is calculated by dividing the weight of the slab 5 by the calculated volume. The thermal expansion coefficient calculation unit 102 extracts the specific gravity of the slab 5 corresponding to the material of the slab 5 from the specific gravity DB 110, and the specific gravity obtained by extracting the slab weight per unit volume calculated by the unit weight calculation unit 101. The thermal expansion coefficient of the slab is calculated by dividing by. The slab temperature calculation unit 103 cuts the temperature of the slab 5 corresponding to the material of the slab 5 from the thermal expansion coefficient DB 120 and the thermal expansion coefficient of the slab 5 calculated by the thermal expansion coefficient calculation unit 102 by the torch 10. Extracted as the temperature of the cast slab 5. Then, the solidification completion position calculation unit 104 calculates the solidification completion position of the slab 5 using the temperature of the slab 5 extracted by the slab temperature calculation unit 103. According to such solidification completion position calculation processing, the slab temperature calculation unit 104 calculates the temperature of the slab 5 cut every time the slab 5 is cut by the torch 10, and the solidification completion position calculation unit Since 104 calculates the solidification completion position of the slab 5 based on the temperature of the slab 5 calculated by the slab temperature calculation unit 104, the solidification completion position of the slab 5 can be calculated with high accuracy online.

  In the solidification completion position calculation process according to the embodiment of the present invention, the slab temperature calculation unit 103 calculates a difference value between the slab temperature and the slab temperature calculated by the solidification model using the solidification model. The solidification completion position calculation unit 104 corrects the temperature calculated by the solidification model using the correction value calculated by the slab temperature calculation unit 103 and corrects the corrected temperature. The solidification completion position of the slab is calculated by calculating the solidification model using. According to such solidification completion position calculation processing, the solidification model can be corrected online, and the solidification completion position of the slab can be calculated with high accuracy online.

  Although the embodiment to which the invention made by the present inventor is applied has been described above, the present invention is not limited by the description and the drawings that form a part of the disclosure of the present invention according to this embodiment. That is, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on the present embodiment are all included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Molten steel 2 Tundish 3 Immersion nozzle 4 Mold 5 Casting piece 6 Casting piece support roll 7 Thermometer 8 Secondary cooling spray 9 Measuring roll 10 Torch (cutting machine)
DESCRIPTION OF SYMBOLS 11 Weighing machine 12 Light pressure lower belt 13 Process computer 100 Solidification completion position calculation apparatus 101 Single weight calculation part 102 Thermal expansion coefficient calculation part 103 Slab temperature calculation part 104 Solidification position calculation part 110 Specific gravity database (DB)
120 Thermal expansion coefficient database (DB)
130 Output device

Claims (3)

A solidification completion position calculation method for a slab that calculates a solidification completion position of a slab cast in a continuous casting machine,
Calculate the volume of the slab using information on the length, width, and thickness of the slab cut by the cutting machine, and divide the weight of the slab by the calculated volume. A unit weight calculating step for calculating the weight of the slab;
Calculate the specific gravity of the slab corresponding to the material of the slab using specific gravity data indicating the relationship between the material and specific gravity of the slab, and the weight of the slab per unit volume calculated in the unit weight calculation step A thermal expansion coefficient calculation step of calculating a thermal expansion coefficient of the slab by dividing by the calculated specific gravity;
A casting for calculating the temperature of the slab cut by the cutting machine from the thermal expansion coefficient of the slab calculated in the thermal expansion coefficient calculation step using the thermal expansion coefficient data indicating the relationship between the thermal expansion coefficient of the slab and the temperature. One temperature calculation step;
A solidification completion position calculating step for calculating a solidification completion position of the slab using the temperature of the slab calculated in the slab temperature calculation step;
The solidification completion position calculation method of the slab characterized by including these.   The slab temperature calculating step includes a step of calculating a difference value between a slab temperature and a slab temperature calculated by a solidification model as a correction value of a slab temperature calculated by a solidification model, The completion position calculating step includes a step of correcting the temperature calculated by the solidification model using the correction value, and calculating a solidification completion position of the slab by calculation of the solidification model using the corrected temperature. The solidification completion position calculation method of the slab of Claim 1 characterized by these. A slab solidification completion position calculating device for calculating a solidification completion position of a slab cast in a continuous casting machine,
A specific gravity database for storing specific gravity data indicating the relationship between the material and specific gravity of the slab;
A thermal expansion coefficient database storing thermal expansion coefficient data indicating the relationship between the thermal expansion coefficient of the slab and the temperature for each material of the slab;
Calculate the volume of the slab using information on the length, width, and thickness of the slab cut by the cutting machine, and divide the weight of the slab by the calculated volume. A unit weight calculation unit for calculating the weight of the slab,
By extracting the specific gravity of the slab corresponding to the material of the slab from the specific gravity database, and dividing the weight of the slab per unit volume calculated by the unit weight calculation unit by the extracted specific gravity A thermal expansion coefficient calculation unit for calculating the thermal expansion coefficient of
The temperature of the slab corresponding to the material of the slab and the thermal expansion coefficient of the slab calculated by the thermal expansion coefficient calculator is extracted from the thermal expansion coefficient database as the temperature of the slab cut by the cutting machine. A slab temperature calculator,
A solidification completion position calculation unit that calculates a solidification completion position of the slab using the temperature of the slab extracted by the slab temperature calculation unit;
A slab solidification completion position calculating device comprising:

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