Cast slab cutting length control method and cutting length control system

Abstract

To provide a method and system for controlling a cutting length of a cast slab that allows for improving the production yield of a cast slab by reducing a difference between an actually measured weight and a target weight of the cast slab.SOLUTION: A method of controlling a cutting length of a cast slab according to the present invention, for controlling a cutting length of a cast slab to be cut so as to match the weight of a cast slab obtained by cutting a strand cast at a continuous casting machine with a target weight, includes: a weighing step that weighs the weight of a cast slab last cut as an actually measured weight; and a determining step that determines a cutting length of the cast slab to be cut based on a difference between the actually measured weight weighed at the weighing step and a target weight of the cast slab last cut.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method and system for controlling the cut length of a cast slab. [Background technology]

[0002] Typically, the cut length of a cast slab by a cutter located at the outlet of a continuous casting machine is determined based on the target weight of the cast slab plus weight variation. If the weight of the cast slab is less than the target weight, the product length will be shorter than the target length, and the desired product will not be obtained, resulting in wasted processing and a reduced production yield. On the other hand, if the weight of the cast slab is greater than the target weight, cutting work will be required, additional processes will be added, and raw iron will be wasted. Therefore, if the cut length of the cast slab can be determined within a range that minimizes weight variation and does not fall below the target weight, the production yield of the cast slab can be improved. Against this background, a method has been proposed for correcting the cut length of a cast slab based on the cooling conditions of the cast slab in the continuous casting machine, taking into account the correlation between weight variation and the cross-sectional temperature of the cast slab.

[0003] Specifically, Patent Document 1 describes a method for correcting the cut length of a cast slab by experimentally formulating the relationship between the actual cooling water volume in a continuous casting machine and the weight per unit length of the cast slab, and then using the weight per unit length of the cast slab calculated from this relationship. Patent Document 2 describes a method for correcting the cut length of a cast slab by utilizing the correlation between the final solidification position of the cast slab and the cross-sectional temperature of the cast slab. More specifically, the method described in Patent Document 2 experimentally formulates the relationship between the value obtained by directly sensing the final solidification position and the weight per unit length of the cast slab, and calculates the weight per unit length of the cast slab based on the measured value of the final solidification position to correct the cut length of the cast slab. Furthermore, Patent Document 3 describes a method for correcting the cut length of a cast slab based on the residence time of the cast slab in the machine. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2017-202505 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-131268 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-108449 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the methods described in Patent Documents 1 to 3 all involve so-called feedforward cut-length control methods, in which the cut length of a cast slab is corrected based on previously obtained cast slab information. Therefore, variations in the weight of the cast slab may occur when operational conditions change. Furthermore, the methods described in Patent Documents 1 to 3 all correct the cut length of a cast slab based on a formula determined from a large amount of operational performance data with variations using techniques such as multiple regression analysis. Therefore, variations in the weight of the cast slab remain. Furthermore, since there is no feedback of the weight of the actually cut cast slab, systematic weight errors remain. Given these factors, a technology capable of reducing the difference between the measured weight of a cast slab and the target weight and improving the production yield of cast slabs has been anticipated.

[0006] The present invention has been made to solve the above-mentioned problems, and its object is to provide a method and system for controlling the cutting length of a cast slab that can reduce the difference between the actual weight and the target weight of the cast slab, thereby improving the production yield of the cast slab. [Means for solving the problem]

[0007] The method for controlling the cutting length of a cast slab according to the present invention is a method for controlling the cutting length of a cast slab to be cut so that the weight of the cast slab obtained by cutting a cast strand cast in a continuous casting machine matches a target weight, and includes a weighing step for measuring the weight of the most recently cut cast slab as an actual measured weight, and a determination step for determining the cutting length of the cast slab to be cut based on the difference between the actual measured weight measured in the weighing step and the target weight of the most recently cut cast slab.

[0008] The determining step may include a step of determining a cutting length of the cast slab to be cut using a value obtained by multiplying a target weight of the cast slab to be cut by an estimated weight correction coefficient calculated by the following formula (1):

[0009]

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[0010] Here, the calculated weight is the weight of the most recently cut cast slab calculated from the dimensions of the most recently cut cast slab, the actual weight is the actual weight weighed in the weighing step, the target addition rate is the excess length of the most recently cut cast slab set for the target weight of the most recently cut cast slab, and the used weighing correction coefficient is the correction coefficient for the target weight used when determining the cutting length of the most recently cut cast slab.

[0011] The cast slab cutting length control system of the present invention is a cast slab cutting length control system that controls the cutting length of a cast slab to be cut so that the weight of the cast slab obtained by cutting a cast strand cast in a continuous casting machine matches a target weight, and is equipped with a weighing means that measures the weight of the most recently cut cast slab as an actual weight, and a determination means that determines the cutting length of the cast slab to be cut based on the difference between the actual weight measured by the weighing means and the target weight of the most recently cut cast slab. [Effects of the Invention]

[0012] According to the method and system for controlling the cut length of a cast slab according to the present invention, the difference between the actual weight and the target weight of the cast slab can be reduced, thereby improving the production yield of the cast slab. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a cast slab cutting length control system according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, the configuration and operation of a cast slab cutting length control system according to one embodiment of the present invention will be described with reference to the drawings.

[0015] Fig. 1 is a schematic diagram showing the configuration of a cast slab cut length control system according to one embodiment of the present invention. As shown in Fig. 1, the cast slab cut length control system 1 according to one embodiment of the present invention is a system that controls the cut length L of the cast slab S to be cut so that the weight of the cast slab S obtained by cutting a cast strand ST cast in a continuous casting machine 2 matches a target weight. In this embodiment, the cast slab cut length control system 1 includes a weighing table 11, a business computer 12, a process computer 13, and a slab cutter 14 as its main components.

[0016] The weighing table 11 is a transport table provided adjacent to the downstream side of the cutting table 3 that transports the cast strand ST and cast slab S, and is equipped with transport rolls and a weighing machine (not shown). The transport rolls transport the cut cast slab S0 in the direction of the arrow in the figure. The weighing machine (not shown) measures the weight of the cast slab S0 transported onto the weighing table 11 as a weighed value (actual weight) and inputs an electrical signal indicating the measured weighed value into the process computer 13.

[0017] The business computer 12 is configured by an information processing device such as a workstation, and stores information about the cast slab S to be cut and information about the cast slab S0 that was cut most recently. The information about the cast slab S to be cut includes the thickness, width, target weight, target addition rate, specific gravity (for example, 7.85 g / cm3) of the cast slab S to be cut. 3 The target addition rate refers to the extra length (range: 0 to 0.05) of the cast slab S that is set with respect to the target weight of the cast slab S to be cut.

[0018] The information about the most recently cut cast slab S0 includes information such as the weighing value (actual weight) of the cast slab S0, the calculated weight, the target addition rate, and the weighing correction coefficient used (described later). The calculated weight of the cast slab S0 can be calculated from the actual values ​​of the thickness, width, and cut length L of the cast slab S0, and the specific gravity. At a predetermined timing, such as when the continuous casting machine 2 starts operating, the business computer 12 inputs information about the cast slab S to be cut and information about the most recently cut cast slab S0 into the process computer 13 as production command information.

[0019] The process computer 13 is configured with an information processing device such as a personal computer, and is electrically connected to the weighing table 11, the business computer 12, and the slab cutting machine 14. The process computer 13 determines the cutting length L of the cast slab S to be cut using production command information input from the business computer 12, and controls the slab cutting machine 14 so as to cut the cast slab S to be cut at the determined cutting length L. Specifically, first, the process computer 13 calculates a correction coefficient for the target weight of the cast slab S to be cut as an estimated weighing correction coefficient based on the difference between the actual weight of the most recently cut cast slab S0 and the target weight using the following mathematical formula (1):

[0020]

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[0021] Here, in formula (1), the calculated weight indicates the calculated weight of the most recently cut cast slab S0, and the actual weight indicates the actual measured weight of the most recently cut cast slab S0. The target addition rate indicates the target addition rate of the most recently cut cast slab S0, and the used weighing correction coefficient indicates the correction coefficient for the target weight of the cast slab S0 used when determining the cutting length L of the most recently cut cast slab S0. In this embodiment, the process computer 13 calculates the estimated weighing correction coefficient, but the business computer 12 may also calculate the estimated weighing correction coefficient and input it to the process computer 13.

[0022] Next, the process computer 13 calculates a correction weight by multiplying the target weight of the cast slab S to be cut by (1 + the target addition rate of the cast slab S to be cut) and the estimated weighing correction coefficient. Next, the process computer 13 divides the calculated correction weight by the specific gravity, and calculates the cut length L of the cast slab S to be cut by dividing the calculated value by the thickness and width of the cast slab S to be cut. Then, the process computer 13 inputs information indicating the calculated cut length L to the slab cutting machine 14 as cut length information, and the slab cutting machine 14 cuts the cast slab S in accordance with the input cut length information.

[0023] As is clear from the above description, in the cast slab cut length control system 1 according to one embodiment of the present invention, the process computer 13 determines the cut length L of the cast slab S to be cut based on the difference between the measured weight of the most recently cut cast slab S0 and the target weight. That is, the process computer 13 determines the cut length L of the cast slab S to be cut by feeding back the error in the weight of the most recently cut cast slab S0. With this configuration, the cut length L of the cast slab S to be cut can be controlled taking into account the variation in weight of the most recently cut cast slab S0, thereby reducing the difference between the measured weight of the cast slab S and the target weight, thereby improving the production yield of the cast slabs S.

[0024] Although the present invention has been described above as an embodiment, the present invention is not limited to the descriptions and drawings that form part of the disclosure of the present invention. In other words, other embodiments, examples, and operational techniques that can be made by those skilled in the art based on the present invention are all included in the scope of the present invention. [Explanation of symbols]

[0025] 1 Cast slab cutting length control system 2. Continuous casting machine 3 Cutting Table 11 Weighing table 12 Business Computers 13 Process Computer 14 Slab cutting machine S, S0 cast slab ST Casting Strand

Claims

1. A method for controlling a cut length of a cast slab, the method comprising: controlling a cut length of a cast slab to be cut so that a weight of the cast slab obtained by cutting a cast strand cast in a continuous casting machine matches a target weight; a weighing step of measuring the weight of the most recently cut cast slab as an actual weight; a determining step of determining a cutting length of the cast slab to be cut based on a difference between the actual weight measured in the weighing step and a target weight of the most recently cut cast slab; Including, The method for controlling the cutting length of a cast slab includes a step of determining the cutting length of the cast slab to be cut using a value obtained by multiplying the target weight of the cast slab to be cut by an estimated weighing correction coefficient calculated by the following formula (1). [Equation 1] Here, the calculated weight is the weight of the most recently cut cast slab calculated from the dimensions of the most recently cut cast slab, the actual weight is the actual weight weighed in the weighing step, the target addition rate is a predetermined fixed cast slab extension length, and the used weighing correction coefficient is the correction coefficient of the target weight used when determining the cutting length of the most recently cut cast slab.

2. 1. A cast slab cut length control system for controlling the cut length of a cast slab to be cut so that the weight of the cast slab obtained by cutting a cast strand cast in a continuous casting machine matches a target weight, a weighing means for measuring the weight of the most recently cut cast slab as an actual weight; a determining means for determining a cutting length of the cast slab to be cut based on a difference between the actual weight measured by the weighing means and the target weight of the most recently cut cast slab; Equipped with The determination means determines the cutting length of the cast slab to be cut using a value obtained by multiplying the target weight of the cast slab to be cut by an estimated weighing correction coefficient calculated by the following formula (1), a cast slab cutting length control system. [Equation 2] Here, the calculated weight is the weight of the most recently cut cast slab calculated from the dimensions of the most recently cut cast slab, the actual weight is the actual weight weighed by the weighing means, the target addition rate is a predetermined fixed cast slab extension length, and the used weighing correction coefficient is the correction coefficient of the target weight used when determining the cutting length of the most recently cut cast slab.

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