Rolling setting assistance device and rolling setting assistance method

Abstract

To enable appropriate selection of a rolling process condition to be optimized so as to manufacture a rolling material having desired mechanical material quality.SOLUTION: A rolling setting assistance device 15 comprises: a material singular point / reference point calculation unit 152a that detects a material singular point at which a mechanical material singularity is generated in the longitudinal direction of a rolling material 4; a tissue feature amount selection unit 152c that selects a tissue feature amount of the rolling material 4 high in correlation with a mechanical material the mechanical material singularity of which has been detected; an element process identification unit 152d that identifies an element process of a hot rolling line 3 where the mechanical material singularity has been generated on the basis of information about the selected tissue feature amount; and a process condition optimization unit 152e that optimizes a process condition in the identified element process.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a rolling setting support device and a rolling setting support method. [Background technology]

[0002] In the hot rolling field, slabs (steel billets) with an initial temperature of around 1200°C are rolled ten or more times to produce rolled material with a thickness of 1 to 12 mm and a length of approximately 400 to 2000 m. It is known that the mechanical properties of the produced rolled material, such as strength and elongation, vary depending on the hot rolling conditions, and therefore it is necessary to take the mechanical properties of the rolled material into consideration when setting control target values ​​for hot rolling.

[0003] Patent Document 1 discloses a set value calculation device that includes a metallographic structure prediction unit that predicts the metallographic structure of a rolled material, a mechanical property prediction unit that predicts mechanical properties based on the predicted metallographic structure and chemical composition, an influence coefficient calculation unit that calculates an influence coefficient of a control set value for the predicted mechanical properties, and a set calculation condition change unit that changes the set calculation conditions based on the mechanical properties required for the rolled material and the deviation of the mechanical properties and the influence coefficient, and causes the set calculation unit to calculate control set values.The technology described in Patent Document 1 makes it possible to calculate control set values ​​with good accuracy for achieving target mechanical properties. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-133246 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology described in Patent Document 1 calculates influence coefficients of control settings for mechanical materials and determines control settings that satisfy target mechanical properties. However, the technology in Patent Document 1 does not disclose a method for selecting control setting items to be used for calculating influence coefficients from the many control setting items. There are more than several dozen setting items used in hot rolling, such as the reduction ratio, strip threading speed, and temperature in each rolling pass of a hot rolling line, and the open / closed status of multiple cooling nozzles in a cooling device before coiling the rolled material. Therefore, calculating influence coefficients for all of these setting items poses challenges in terms of calculation load and calculation time. Furthermore, sequentially changing a large number of setting items based on influence coefficients also poses challenges in terms of calculation convergence.

[0006] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to make it possible to appropriately select rolling process conditions that should be optimized to enable the production of rolled material having desired mechanical properties. [Means for solving the problem]

[0007] A rolling setting support device according to one aspect of the present invention includes a material singularity detection unit that detects material singularities, which are locations where mechanical material singularities occur in the longitudinal direction of a rolled material that is a target for setting support of rolling conditions in a hot rolling line; a texture feature selection unit that selects texture features of the rolled material that are highly correlated with the mechanical material in which the material singularity has been detected; an element process identification unit that identifies an element process of the hot rolling line in which the mechanical material singularity has occurred, based on information about the texture feature selected by the texture feature selection unit; and a process condition optimization unit that optimizes the process conditions in the element process identified by the element process identification unit. [Effects of the Invention]

[0008] According to at least one aspect of the present invention, it becomes possible to appropriately select rolling process conditions that should be optimized to enable the production of rolled material having desired mechanical properties. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram showing an example of the configuration of a hot rolling system according to a first embodiment of the present invention. [Figure 2] 1 is a block diagram showing an example of the configuration of a control system of a rolling setting support device according to a first embodiment of the present invention. [Figure 3] FIG. 2 is a diagram showing an example of the configuration of rolling data according to the first embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing an example of the configuration of rolling data according to the first embodiment of the present invention. [Figure 5] 3 is a graph showing the distribution of tensile strength in the longitudinal direction of the rolled material according to the first embodiment of the present invention. [Figure 6] 10 is a graph showing absolute values ​​of correlation coefficients between mechanical materials used as a criterion for selecting material singular points according to the first embodiment of the present invention and each structure feature amount. [Figure 7] FIG. 2 is a diagram illustrating an example of the configuration of an organization feature causal relationship DB according to the first embodiment of the present invention. [Figure 8] 1 is a graph showing an example of the distribution in the longitudinal direction of a rolled material of the correlation between tensile tension, as an example of a mechanical material property, and the average austenite grain size, as an example of a structural feature quantity, according to the first embodiment of the present invention. [Figure 9] 4 is a graph showing the difference values ​​between the material singular points and the reference points of the average austenite grain size in each element process of the rolling process according to the first embodiment of the present invention. [Figure 10] FIG. 2 is a diagram showing an example of the configuration of a process condition DB according to the first embodiment of the present invention. [Figure 11] 3 is a flowchart showing an example of a procedure for rolling setting support processing by the rolling setting support device according to the first embodiment of the present invention. [Figure 12] 3 is a flowchart showing an example of a procedure for a process condition optimization process according to the first embodiment of the present invention. [Figure 13]10 is a graph showing the distribution of tensile strength in the longitudinal direction of a rolled material, which is referred to by a material singularity and reference point selection unit when selecting material singularities and reference points from a plurality of rolled materials, according to a modified example of the present invention. [Figure 14] FIG. 4 is a block diagram showing an example of the configuration of a hot rolling system according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In each drawing, the same components are designated by the same reference numerals. The following description and drawings are examples for explaining the present invention, and for clarity of explanation, appropriate omissions and simplifications have been made. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0011] 1. First embodiment <Hot rolling system configuration> First, the configuration of a hot rolling system including a rolling setting support device according to a first embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a block diagram showing an example of the configuration of a hot rolling system 100 according to the first embodiment of the present invention.

[0012] As shown in Fig. 1, the hot rolling system 100 includes a rolling control system 1, a host system 2, and a hot rolling line 3. The host system 2 issues production instructions for a rolled material 4 to the rolling control system 1. The rolling control system 1 determines a rolling control target value based on specification data for the rolled material included in the production instructions input from the host system 2, and controls the operation of the hot rolling line 3 based on the determined rolling control target value. The hot rolling line 3 rolls the rolled material 4 based on the control by the rolling control system 1.

[0013] [Hot rolling line] The hot rolling line 3 includes a heating furnace 310 , a transfer line 311 , a roughing mill 312 , a finishing mill 314 , a cooling device 315 , and a winder 316 . The heating furnace 310 heats a slab as the rolled material 4 to a temperature of 1200°C or the like and supplies it to a transfer line 311. The transfer line 311 transfers the rolled material 4 heated by the heating furnace 310 to a winder 316 located at the end of the hot rolling line 3.

[0014] The roughing mill 312 includes one rolling stand. The rolling stand of the roughing mill 312 rolls the rolled material 4 in the thickness direction and width direction by rolling the rolled material 4 multiple times (reciprocating rolling) while reversing the conveying direction of the rolled material 4. The finishing mill 314 is composed of multiple rolling stands lined up along the conveying line 311, and each of the multiple rolling stands rolls the rolled material 4 to roll the rolled material 4 in the thickness direction.

[0015] The cooling device 315 has a plurality of cooling nozzles (not shown) and cools the rolled material 4 by discharging cooling water from the cooling nozzles onto the rolled material 4. The opening degree of the cooling nozzles of the cooling device 315 is controlled by the rolling control device 12 of the rolling control system 1 based on information such as the control target temperature and temperature history of the rolled material 4. The rolled material 4 cooled by the cooling device 315 is wound into a roll by a winder 316.

[0016] Furthermore, thermometers for measuring the temperature of the rolled material 4 are installed at multiple locations in the hot rolling line 3. In the example shown in FIG. 1 , the hot rolling line 3 is equipped with a roughing mill entrance thermometer 320, a roughing mill exit thermometer 321, a finish rolling entrance thermometer 322, a finish rolling exit thermometer 323, and a winder entrance thermometer 324. Note that the thermometers installed in the hot rolling line 3 are not limited to those shown in FIG. 1 , and additional thermometers may be installed between the rolling stands of the finish rolling mill 314. Furthermore, additional thermometers may be installed in the cooling device 315. Each of these thermometers measures the temperature of the rolled material 4 passing through the observation point of the thermometer, and outputs information on the measured temperature to the rolling control system 1 as operation data.

[0017] Although not shown in Fig. 1, each rolling stand of the roughing mill 312 and the finishing mill 314 is provided with a measuring instrument. The measuring instrument measures the state of the rolls, including information on the load applied to the rolls of the rolling stand and information on the rotational speed of the rolls. The measuring instrument outputs the measured state of the rolls to the rolling control system 1 as operation data.

[0018] [Rolling control system] The rolling control system 1 includes a rolling setting device 11 , a rolling control device 12 , an operation data collection device 13 , a data storage device 14 , and a rolling setting support device 15 . The rolling setting device 11 determines a rolling control target value based on the specification data of the rolled material 4 and the rolling conditions of the hot rolling line 3 input from the rolling setting support device 15, and outputs the determined pressure control target value to the rolling control device 12.

[0019] The rolling control device 12 controls the operation of each piece of equipment included in the hot rolling line 3 based on the pressure control target value input from the rolling setting device 11 . The operation data collection device 13 collects operation data of the hot rolling line 3 from the rolling control device 12. The operation data indicates various data measured during rolling in each facility of the hot rolling line 3. The operation data includes, for example, the thickness of the rolled material after each rolling run at multiple points in the longitudinal direction of the rolled material, the temperature of the rolled material 4 measured by various thermometers installed in the hot rolling line 3, etc.

[0020] The data storage device 14 stores various data in the rolling control system 1. The data stored in the data storage device 14 includes rolling data 141a, a metallurgical model 141b, a structure feature causal relationship DB 141c, a process condition DB 141d, and the like.

[0021] The rolling data 141a is data that is composed of specification data on the mechanical materials (mechanical properties) required for the rolled material 4, data on the rolled material 4 itself, and operation data obtained in each process of the hot rolling line 3. An example of the configuration of the rolling data 141a will be described in detail below with reference to Figs. 3 and 4.

[0022] Metallurgical model 141b is a theoretical model that faithfully mathematically represents metallurgical phenomena. For example, the metallurgical model described in "Material Control and Prediction" published by the Iron and Steel Institute of Japan in 1988 can be used as metallurgical model 141b.

[0023] The structure feature causal relationship DB 141c is a database in which metallurgical knowledge regarding the causal relationships between structure feature quantities is described. The structure feature causal relationship DB 141c is referenced by a structure feature selection unit 152c of the rolling setting support device 15, which will be described later. The structure feature causal relationship DB 141c will be described in detail with reference to Fig. 7, which will be described later.

[0024] The process condition DB 141d is a database that stores process conditions set for each element process of the hot rolling line 3. The process condition DB 141d is referenced by a process condition optimization unit 152e of the rolling setting support device 15, which will be described later. The process condition DB 141d will be described in detail with reference to FIG. 10, which will be described later.

[0025] The rolling setting support device 15 uses the data stored in the data storage device 14 to set the rolling conditions for each facility in the hot rolling line 3, thereby supporting the rolling setting device 11 in determining rolling control target values. The rolling control target values ​​are values ​​that enable the mechanical properties (material properties) of the rolled material 4 to be set to desired properties (material properties). The rolling control target values ​​are set based on the rolling conditions in the case where the material properties of the rolled material 4 predicted when rolling is performed based on the rolling conditions become the target material properties. Then, until the predicted material properties of the rolled material 4 become the target material properties, the rolling conditions are changed, the material properties of the rolled material 4 predicted when rolling is performed based on the changed rolling conditions are predicted, and a determination is made as to whether the predicted mechanical properties of the material properties become the target material properties, i.e., the optimization of the rolling conditions is repeated.

[0026] However, there are several tens of types of rolling conditions that need to be changed, such as the reduction ratio of the rolled material 4 in each rolling stand of the hot rolling line 3, the sheet threading speed, the temperature, and the open / closed state of the numerous cooling nozzles in the cooling device 315. Therefore, if it is not possible to appropriately select the rolling conditions that need to be changed in order to achieve the target mechanical properties, it will be impossible to optimize the rolling conditions.

[0027] In response to this, the inventors of the present invention focused on the existence of material quality unevenness in the longitudinal direction of the rolled material 4 and came up with a method of optimizing the rolling conditions based on information about the material quality unevenness. Specifically, the inventors came up with a method of identifying elemental processes that cause material quality unevenness in the hot rolling line 3 and selecting the process conditions (rolling conditions) in the identified elemental processes as the rolling conditions to be optimized.

[0028] The rolling setting support device 15 of the rolling control system 1 according to this embodiment first detects material singularities, which are locations where mechanical material singularities occur in the longitudinal direction of the rolled material 4. Then, the rolling setting support device 15 selects structural feature amounts of the rolled material that have a high correlation with the mechanical material at which the material singularity was detected, and identifies an elemental process of the hot rolling line 3 at which the mechanical material singularity occurred, based on information on the selected structural feature amount. Furthermore, the rolling setting support device 15 optimizes process conditions for the identified elemental process, and outputs rolling conditions including the optimized process conditions to the rolling setting device 11. The configuration of the rolling setting support device 15 will be described in detail with reference to the following FIG. 2.

[0029] (Configuration of rolling setting support device) Next, the configuration of the rolling setting support device 15 will be described with reference to Fig. 2. Fig. 2 is a block diagram showing an example of the configuration of a control system of the rolling setting support device 15. As shown in FIG. 2, the rolling setting support device 15 includes a data storage unit 151 , a calculation unit 152 , a memory 153 , an input unit 154 , an output unit 155 , and a data transmission / reception unit 156 .

[0030] The data storage unit 151 is configured with a non-volatile storage such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The data storage unit 151 stores a software program (hereinafter also simply referred to as a "program") for executing the rolling setting support processing according to this embodiment. The program is stored in the form of computer-readable program code. The data storage unit 151 also stores input / output data to and from the program.

[0031] The calculation unit 152 is configured with a processing device such as a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit), and executes the program by reading out the code of the program stored in the data storage unit 151 and expanding it in the memory 153. As a result, the rolling setting support device 15 according to this embodiment sequentially executes operations in accordance with the program code.

[0032] The calculation unit 152 also includes a structure feature and mechanical material calculation unit 152a, a material singularity and reference point selection unit 152b, a structure feature selection unit 152c, an element process identification unit 152d, a process condition optimization unit 152e, and a rolling condition determination unit 152f.

[0033] The structure feature quantity and mechanical material calculation unit 152a sets at least two or more calculation points in the longitudinal direction of the rolled material 4. Then, the structure feature quantity and mechanical material calculation unit 152a calculates, at each of the set calculation points, the structure feature quantity of the rolled material 4 during rolling by the hot rolling line 3 and the mechanical material of the rolled material 4 after it has been cooled to room temperature. The structure feature quantity and mechanical material calculation unit 152a can determine the structure feature quantity and the mechanical material at each calculation point on the rolled material 4, for example, by applying the metallurgical model 141b to the rolling data 141a.

[0034] The tissue feature amount calculated by the tissue feature amount and mechanical material calculation unit 152a includes at least one of the following. The ratio of well-known metal structures such as austenite, ferrite, pearlite, bainite, and martensite contained in the rolled material 4 Average grain size of austenite or ferrite contained in rolled material 4 Lamellar spacing of pearlite in rolled material 4 - Size of bainite laths contained in rolled material 4 Width of lath, packet size, or block size of martensite contained in rolled material 4

[0035] The mechanical properties calculated by the structure feature amount and mechanical property calculation unit 152a include at least one of the yield strength, tensile strength, elongation, and hardness of the rolled material 4.

[0036] The texture feature quantity and mechanical material calculation unit 152a can arrange the calculation points in the longitudinal direction of the rolled material 4, for example, starting from a point x￢0 m from the front end of the rolled material 4 to the rear end portion of the rolled material 4 at intervals of Δx, such as x￢0, x￢0 + Δx, x￢0 + 2Δx, , x￢0 + (Nx-1)Δx. Note that the texture feature quantity and mechanical material calculation unit 152a may change the size of Δx, which is the arrangement interval of the calculation points, depending on the position in the longitudinal direction of the rolled material 4. For example, the texture feature quantity and mechanical material calculation unit 152a may make Δx smaller at the front end and rear end of the rolled material 4, where temperature changes are likely to be relatively large, and make Δx larger in the central portion of the rolled material 4.

[0037] The material singularity and reference point selector 152b (an example of a material singularity detector) selects one or more material singularities and reference points corresponding to the material singularities from among the multiple calculation points set on the rolled material 4 by the texture feature and mechanical material calculation unit 152a. A material singularity is a point having a unique material, and is a location where the mechanical material is higher or lower than normal. For example, the material singularity and reference point selector 152b can set a calculation point that has a large deviation from the mechanical material trend line (see FIG. 5) as a material singularity.

[0038] Furthermore, the material singularity and reference point selection unit 152b sets, as reference points, calculation points that are located near the material singularity and that deviate little from the trend line. The selection process of material singularity and reference points by the material singularity and reference point selection unit 152b will be described in detail later with reference to FIG. 5.

[0039] The texture feature amount selection unit 152c selects the texture feature amount that caused the peculiar material to occur. The texture feature amount selection process by the texture feature amount selection unit 152c will be described in detail later with reference to FIGS.

[0040] The elemental process identifying unit 152d identifies an elemental process of the rolling process in which a difference in mechanical material quality observed between the material singular point and the reference point has occurred. More specifically, the elemental process identifying unit 152d identifies an elemental process in which a difference in mechanical material quality has occurred by examining changes in structure feature amounts that are highly correlated with mechanical material quality during the rolling process in the hot rolling line 3.

[0041] The elemental process identification unit 152d can calculate the structural feature values ​​during the rolling process by using, for example, a calculation model constructed using data from hot working experiments. The calculation model is disclosed, for example, in "Material Control and Prediction" (1988, Iron and Steel Institute of Japan). The elemental process identification unit 152d may determine the identification of the elemental process at which the difference in mechanical material properties has occurred based on an instruction input by the user U. The user U can identify the elemental process at which the difference in mechanical material properties has occurred by referring to, for example, a graph displayed on the output unit 155, which shows the change during the rolling process in the structural feature values ​​that are highly correlated with the mechanical material properties. The graph showing the change during the rolling process in the structural feature values ​​will be described in detail with reference to FIG. 9 below.

[0042] The process condition optimization unit 152e optimizes the process conditions of the element processes identified by the element process identification unit 152d. The process condition optimization unit 152e can extract the process conditions of the element processes identified by the element process identification unit 152d from the process condition DB 141d stored in the data storage unit 151. The configuration of the process condition DB 141d and the optimization process of the extracted process conditions will be described in detail with reference to FIG. 12 below.

[0043] The rolling condition determination unit 152f determines rolling conditions including the process conditions optimized by the process condition optimization unit 152e, that is, rolling conditions for the entire hot rolling line 3. Details of the rolling condition determination process by the rolling condition determination unit 152f will be described later.

[0044] The memory 153 includes, for example, a read-only memory (ROM) and a random access memory (RAM). Variables, parameters, and the like generated during calculations by the calculation unit 152 (during program operation) are temporarily written to the RAM of the memory 153. The program may be stored in the ROM. In other words, the ROM or the data storage unit 151 is used as an example of a computer-readable non-transitory recording medium that stores a program executed by a computer.

[0045] The input unit 154 is configured with, for example, a keyboard, a mouse, a touch sensor, etc., and generates an operation signal according to an operation by the user U and supplies it to the calculation unit 152. The output unit 155 is, for example, a monitor configured with an LCD (Liquid Crystal Display) or the like, and displays the results of the processing performed in the rolling setting support device 15. Alternatively, the output unit 155 may be equipped with a speaker or the like that outputs sound. Note that the output unit 155 as a display unit and the input unit 154 may be configured integrally as a touch panel.

[0046] For example, a NIC (Network Interface Card) or the like is used for the data transmission / reception unit 156. The data transmission / reception unit 156 transmits and receives various data to and from the rolling setting device 11 and the data storage device 14 connected via a network, a communication line, or the like. These functional units included in the rolling setting support device 15 are connected to each other so as to be able to communicate with each other via a data bus 157 which is a data transmission path.

[0047] <Rolling data configuration> Next, the configuration of the rolling data 141a will be described with reference to Figures 3 and 4. Figures 3 and 4 are diagrams showing an example of the configuration of the rolling data 141a. 3 and 4, the rolling data 141a is composed of the items "item" and "data." The "item" items include the items "identification data," "mechanical material specification data," "slab data," "rough rolling data," "finish rolling data," and "cooling and coiling data."

[0048] The "identification data" item stores information on the "rolled material identification code" and the "rolled material classification code" as identification information for the rolled material 4. Figure 3 shows an example in which the "rolled material identification code" is "AZ12098101" and the "rolled material classification code" is "SAG805".

[0049] The "mechanical material specification data" item stores the specification data of the mechanical material of the rolled material 4. In the example shown in Fig. 3, the "mechanical material specification data" item stores the upper and lower limit values ​​of the mechanical material's "yield strength (MPa)," "tensile strength (MPa)," "elongation (%)," and "hardness (HV)." In the example shown in Fig. 3, the upper limit value is set to "none," indicating that it is not set.

[0050] The "Slab Data" item stores information about the slab, which is the form of the rolled material 4 before rolling. In the example shown in FIG. 3, the "Slab Data" item stores information about the slab's "components," "slab dimensions (mm)," and "heating furnace." The "components" item stores information about the content (w (weight)%) of each element that makes up the slab, such as "carbon" and "manganese." The "Slab Dimensions" item stores information about the "thickness," "length," and "width" that define the dimensions of the slab. The "Heating Furnace" item stores information about the heating time (seconds) and heating temperature (°C) of the slab in the heating furnace 310 (see FIG. 1).

[0051] The "rough rolling data" item stores information related to the rolling of the rolled material 4 by the roughing mill 312 of the hot rolling line 3. In the example shown in FIG. 3, the "rough rolling data" item stores information on the "number of rolling passes (passes)," "reduction rate (%) or thickness after rolling (mm)," "roll rotation speed (rpm (rounds per minute)) or conveyance speed of the rolled material (mpm (meters per minute))," "rolling start time at the front end of the rolled material," "rolling end time at the tail end of the rolled material," and "rolled material temperature (°C)." Values ​​for each of these items constituting the "rough rolling data" are stored for each pass of reciprocating rolling by the roughing mill 312.

[0052] The "finish rolling data" item stores information related to the rolling of the rolled material 4 by the finishing mill 314 of the hot rolling line 3. In the example shown in Fig. 4, the "finish rolling data" item stores information on the "number of rolling passes (times)," "reduction rate (%) or thickness after rolling (mm)," "roll rotation speed (rpm) or conveyance speed of the rolled material (mpm)," "rolling start time at the front end of the rolled material," "rolling end time at the tail end of the rolled material," "entrance temperature," and "exit temperature."

[0053] The item "Roll rotation speed (rpm) or conveying speed of rolled material (mpm)" stores information such as "start speed," "maximum speed," "end speed," "first acceleration," and "second acceleration." The "first acceleration" and "second acceleration" indicate the first and second accelerations in the several stages of acceleration that are performed as the conveying speed of the rolled material 4 reaches from the start speed to the rated speed. The items "Rolling start time at the front end of the rolled material" and "Rolling end time at the tail end of the rolled material" store values ​​for each round of rolling by the finishing mill 314.

[0054] The "Inlet temperature (°C)" item stores information on each temperature of the rolled material 4 measured in seconds by a finish rolling inlet thermometer 322 arranged at the inlet of the finishing rolling mill 314. The "Outlet temperature °C" item stores information on each temperature of the rolled material 4 measured in seconds by a finish rolling outlet thermometer 323 arranged at the outlet of the finishing rolling mill 314.

[0055] The "Cooling and winding data" item stores information on the "open / close state of the first cooling nozzle group," "open / close state of the second cooling nozzle group," ... "temperature of the rolled material at the winder entrance." The "open / close state of the first cooling nozzle group" and "open / close state of the second cooling nozzle group" items store information on the open / close state in seconds of each of the first cooling nozzles and second cooling nozzles (neither of which is shown) of the cooling device 315. The "temperature of the rolled material at the winder entrance (°C)" item stores information on the temperature of the rolled material 4 measured by the winder entrance thermometer 324 installed at the entrance of the winder 316.

[0056] The ranges (upper limit value, lower limit value) of the mechanical material properties included in the rolling data 141a are ranges for each item of the mechanical material properties calculated by the structure feature amount and the mechanical material calculation unit 152a. The calculation unit 152 of the rolling setting support device 15 stores the rolling data 141a acquired by the data transmission / reception unit 156 from the data storage device 14 in the memory 153.

[0057] <Selection of material singular points and reference points> Next, the selection process of material singular points and reference points by the material singular point and reference point selection unit 152b will be described with reference to Fig. 5. Fig. 5 is a graph showing the distribution of tensile strength as an example of a mechanical material in the longitudinal direction of the rolled material 4. The vertical axis of Fig. 5 represents tensile strength (MPa), and the horizontal axis represents the relative position (%) of the calculation point in the longitudinal direction of the rolled material 4. The relative position of the calculation point is the position obtained by dividing the position of each calculation point in the longitudinal direction by the total length of the rolled material 4.

[0058] In the graph of Fig. 5, each point indicated by a black circle represents a calculation point set in the longitudinal direction of the rolled material 4 by the structure feature quantity and mechanical material calculation unit 152a. The graph shown in Fig. 5 is a graph in the case where the structure feature quantity and mechanical material calculation unit 152a calculates tensile strength as the mechanical material at the calculation point. The curve indicated by a dotted line in the graph of Fig. 5 represents a trend line C of tensile strength. The trend line C can be obtained from conventional data of rolled materials 4 belonging to the same or similar classification. Methods that can be used to obtain the trend line C from conventional data include, for example, moving average, function approximation such as a polynomial, Gaussian process regression, and kernel regression.

[0059] The dashed line drawn horizontally in the graph of Fig. 5 indicates the lower limit value of the tensile strength. This lower limit value is a value shown in the rolling data 141a. Note that in the rolling data 141a shown in Fig. 3, the upper limit value of the tensile strength is "none," that is, no upper limit value is set, and therefore the upper limit value of the tensile strength is not shown in the graph shown in Fig. 5. However, when the target rolled material 4 has an upper limit set for tensile strength, the material singularity and reference point selection unit 152b also takes into account the upper limit value of the tensile strength.

[0060] The vertical double-edged arrow in the graph of FIG. 5 indicates the deviation D from the trend line C at a calculation point. The texture feature and mechanical material calculation unit 152a selects a calculation point with a large deviation amount as a material singularity point Pu. Furthermore, the texture feature and mechanical material calculation unit 152a selects a calculation point that is located near the material singularity point Pu and has a small deviation amount as a reference point Pr. Note that in the example shown in FIG. 4, the texture feature and mechanical material calculation unit 152a selects the material singularity point Pu and the reference point Pr based on information about the tensile strength of the rolled material 4, but the present invention is not limited to this. The texture feature and mechanical material calculation unit 152a may select the material singularity point Pu and the reference point Pr based on a mechanical material other than the tensile strength of the rolled material 4, or a combination of mechanical materials.

[0061] Furthermore, the material singular points Pu and reference points Pr may be selected based on instructions input by the user U via the input unit 154 (see FIG. 2). For example, the tissue feature and mechanical material calculation unit 152a may display the graph shown in FIG. 5 or information equivalent to the graph on the output unit 155, and accept the selection of the material singular points Pu and reference points Pr by the user U.

[0062] <Tissue feature selection process> Next, the tissue feature selection process performed by the tissue feature selection unit 152c will be described with reference to Fig. 6. The tissue feature selection unit 152c identifies (selects) the tissue feature that caused the occurrence of the material singular point Pu identified by the tissue feature and mechanical material calculation unit 152a.

[0063] Fig. 6 is a graph showing the absolute values ​​of the correlation coefficients between the mechanical materials used as the criteria for selecting material singular points and each structural feature. The vertical axis of Fig. 6 shows the type of structural feature, and the horizontal axis shows the absolute value (-) of the correlation coefficient with the mechanical material.

[0064] The correlation coefficient between the mechanical material property and the structure feature amount is calculated using, for example, the following formula (1).

[0065] r=[Σ i (x i -x avg)(y i -y avg )] / [Σ i (x i -x avg ) 2 Σ i (y i -y avg ) 2 ] 1 / 2 t...Formula (1)

[0066] In the above formula (1), “Σ i " indicates the mathematical symbol for sum over i, and "x i " and "y i " indicates the i-th value of two types of discrete data, "x" and "y". avg " and "y avg " indicates the average of "x" and "y", respectively. "r" on the left side indicates Pearson's correlation coefficient.

[0067] In the example shown in Fig. 6, among the structural feature quantities, the correlation coefficient of the average austenite grain size and the correlation coefficient of the average ferrite grain size show high values. In other words, it can be seen that the structural feature quantities highly correlated with the tensile strength (mechanical material property) shown in Fig. 4 are the average austenite grain size and the average ferrite grain size.

[0068] The tissue feature selection process by the tissue feature selection unit 152c can be performed, for example, based on instructions input by the user U via the input unit 154. For example, the tissue feature selection unit 152c displays the graph shown in Fig. 6 or information equivalent to the graph on the output unit 155, and receives the selection of tissue feature values ​​highly correlated with mechanical material properties from the user U. The user U can select the tissue feature value that caused the generation of the peculiar material by interpreting the information on the correlation evaluation results shown in Fig. 6 based on his or her own metallurgical knowledge.

[0069] In the example shown in Fig. 6, the structural feature quantity with the largest absolute value of the correlation coefficient with the tensile strength of the mechanical material is the average grain size of ferrite. However, a user U with metallurgical knowledge can determine that the average grain size of ferrite is affected by the average grain size of austenite.

[0070] In the temperature range of approximately 1200 to 850°C during hot rolling, the rolled material 4, which is a steel material, has an austenite crystalline structure. When this rolled material 4 is cooled to below 800°C, the austenite crystalline structure undergoes a phase transformation to a ferrite crystalline structure. In this phase transformation, ferrite nuclei are first generated at the austenite grain boundaries, and the phase transformation progresses as these nuclei grow. In other words, the structural feature values ​​within a metal structure are generally influenced by other structural feature values ​​that precede them in time. Based on this metallurgical knowledge, the user U can select the structural feature value that caused the occurrence of the peculiar material.

[0071] The texture feature selection unit 152c can also select the texture feature that caused the occurrence of the peculiar material by referring to the texture feature causal relationship DB 141c in which metallurgical knowledge regarding the causal relationships between texture feature values ​​is recorded.

[0072] Fig. 7 is a diagram showing an example of the configuration of the structure feature quantity causal relationship DB 141c. As shown in Fig. 7, the structure feature quantity causal relationship DB 141c has a column of structure feature quantities that have an influence (become a cause) and a column representing structure feature quantities that are affected (become an effect). The example shown in Fig. 7 shows that the average ferrite grain size in the effect column is affected by the average austenite grain size in the cause column, the ferrite fraction in the effect column is affected by the average austenite grain size in the cause column, and the martensite fraction in the effect column is affected by the ferrite fraction in the cause column.

[0073] The tissue feature selection unit 152c first identifies, as the first feature, the tissue feature having the largest absolute value of the correlation coefficient with the mechanical material referenced when the material singularity and reference point selection unit 152b selected the material singularity Pu. Next, the tissue feature selection unit 152c searches the effect column of the tissue feature causal relationship DB 141c for the tissue feature identified as the first feature. If the effect column contains the tissue feature identified as the first feature, the tissue feature selection unit 152c identifies, as the second feature, the tissue feature in the cause column of the corresponding row.

[0074] Furthermore, the texture feature quantity selection unit 152c compares the absolute value of the correlation coefficient between the mechanical material quality and the first feature quantity (hereinafter referred to as the "first correlation coefficient absolute value") with the absolute value of the correlation coefficient between the mechanical material quality and the second feature quantity (hereinafter referred to as the "second correlation coefficient absolute value"). Then, when the ratio of the second correlation coefficient absolute value to the first correlation coefficient absolute value is equal to or greater than a predetermined threshold, the texture feature quantity selection unit 152c selects the second feature quantity as the texture feature quantity. On the other hand, when the ratio of the second correlation coefficient absolute value to the first correlation coefficient absolute value is less than the predetermined threshold, the texture feature quantity selection unit 152c selects the first feature quantity as the texture feature quantity. The threshold is set to a value according to the type of rolled material 4, and a value such as "0.7" can be used, for example.

[0075] Furthermore, the tissue feature selection unit 152c may allow the user U to select the tissue feature that caused the peculiar material to occur by displaying a table or the like on the output unit 155 (see FIG. 2) that allows the correlation between the mechanical material and the selected tissue feature to be confirmed.

[0076] Fig. 8 is a graph showing an example of the distribution of the correlation between tensile tension, as an example of a mechanical property, and the average austenite grain size, as an example of a structural feature, in the longitudinal direction of a rolled material 4. The vertical axis of the graph shown in Fig. 8 represents tensile tension (MPa) and the average austenite grain size (µm), and the horizontal axis represents the relative position (%) of the calculation point in the longitudinal direction of the rolled material 4. In Fig. 8, the average austenite grain size is represented by a white triangle, and the tensile strength is represented by a black circle.

[0077] Fig. 8 shows that the tensile strength tends to be low at positions of approximately 60% to 70% where the average austenite grain size is large. Then, the structure feature selection unit 152c compares the tensile strength at the position of the material singularity point Pu (position of approximately 67%) selected in Fig. 5 with the tensile strength at the position of the reference point Pr (position of approximately 45%). In the example shown in Fig. 8, the tensile strength at the position of the material singularity point Pu (position of approximately 67%) is lower than the tensile strength at the position of the reference point Pr (position of approximately 45%).

[0078] The metal material being rolled is a polycrystal consisting of many metal crystals with different orientations, and the boundaries (grain boundaries) between crystals where the crystal orientation changes hinder the movement of atoms. Therefore, when the average crystal grain size is small, there are more grain boundaries, which reduces the movement of atoms in response to the same external force, resulting in higher mechanical strength. On the other hand, when the average crystal grain size is large, there are fewer grain boundaries, which increases the movement of atoms in response to the same external force, resulting in lower mechanical strength. Therefore, the structure feature selection unit 152c can determine that the metal structure cause of the peculiar material is that the austenite average grain size is relatively large compared to other positions in the longitudinal direction of the rolled material 4. Therefore, the structure feature selection unit 152c selects the austenite average grain size as the structure feature causing the peculiar material.

[0079] <Elemental process specific processing> Next, the element process identification processing by the element process identification unit 152d (see FIG. 2) will be described. The element process identification unit 152d identifies the element process at which a material singularity has occurred at the material singularity Pu selected by the material singularity and reference point selection unit 152b, based on information on the texture feature selected by the texture feature selection unit 152c. Specifically, the element process identification unit 152d identifies the element process at which a difference in mechanical material quality observed between the material singularity Pu and the reference point Pr has occurred, by examining the change in the texture feature selected by the texture feature selection unit 152c during the rolling process.

[0080] The structural feature values ​​in the rolling process can be calculated using a computational model constructed using data from hot working experiments. For example, the aforementioned "Material Control and Prediction" (1988, Iron and Steel Institute of Japan) discloses a model for calculating structural feature values ​​in the rolling process. While the structural feature values ​​in the rolling process are calculable, calculating the mechanical properties in the rolling process is difficult. This is because mechanical properties such as tensile strength are values ​​indicated at room temperature. Therefore, calculating the mechanical properties in the rolling process requires a great deal of effort to construct a computational model. The element process identification unit 152d according to this embodiment uses structural feature values ​​whose values ​​in the rolling process can be calculated to identify the element process in which a material anomaly has occurred. Therefore, according to this embodiment, it is possible to identify the element process in which a material anomaly has occurred in the rolling process without constructing a dedicated computational model.

[0081] 9 is a graph showing the difference (μm) between the material singular point and the reference point of the average austenite grain size in each elemental process of the rolling process in the hot rolling line 3. The horizontal axis represents each elemental process of the rolling process.

[0082] The elemental processes of the rolling process can be classified, for example, as follows, in accordance with the operation of each facility on the hot rolling line 3. The classification below applies to the case where the rolled material 4 is subjected to three rough rollings and six finish rollings on the hot rolling line 3, and then cooled by a cooling device 315 that is controlled by dividing it into four sections.

[0083] Heating process in heating furnace 310 (indicated as "Heating" in the figure) The first transport process from the heating furnace 310 to the roughing mill 312 (indicated as "Transport 1" in the figure) First rough rolling process by roughing mill 312 (denoted as "Roughing 1" in the figure) A second rough rolling process by the rough rolling mill 312 (denoted as "Roughing 2" in the figure) A third rough rolling process by the rough rolling mill 312 (denoted as "Roughing 3" in the figure) The second transport process from the roughing mill 312 to the finishing mill 314 (in the figure, this is referred to as "Transport 2") First finishing rolling process by finishing mill 314 (denoted as "Finishing 1" in the figure) A second finishing rolling process by the finishing mill 314 (denoted as "Finishing 2" in the figure) The third finishing rolling process by the finishing mill 314 (denoted as "Finishing 3" in the figure) A fourth finishing rolling process by the finishing rolling mill 314 (denoted as "Finishing 4" in the figure) A fifth finishing rolling process by the finishing rolling mill 314 (denoted as "Finishing 5" in the figure) A sixth finishing rolling process by the finishing rolling mill 314 (denoted as "Finishing 6" in the figure) First section cooling process of the cooling device 315 (indicated as "Cooling1" in the figure) The second section cooling process of the cooling device 315 (indicated as "Cooling2" in the figure) The third section cooling process of the cooling device 315 (indicated as "Cooling3" in the figure) The fourth section cooling process of the cooling device 315 (indicated as "Cooling4" in the figure)

[0084] In the cooling process, the austenite structure changes to another structure and disappears. Therefore, the cooling process is an elemental process in which the average austenite grain size cannot be defined. In the graph shown in Figure 9, the average grain size immediately before disappearance continues to be displayed in such elemental processes.

[0085] In the graph shown in Fig. 9, the austenite average grain size difference value changes significantly in the first finish rolling process (Finishing 1). In this way, the element process identifying unit 152d can identify an element process (the "first finish rolling process" in the example shown in Fig. 9) in which the amount of change in the difference value from the previous element process (the "second conveying process" in the example shown in Fig. 9) is equal to or greater than a predetermined amount of change, as an element process in which a peculiar property of the material has occurred.

[0086] In addition, the element process identification unit 152d may display the graph shown in Figure 9 or information equivalent to the graph on the output unit 155 (see Figure 2) to allow the user U to select the element process in which the material anomaly occurred.

[0087] <Process condition optimization treatment> Next, the process condition optimization process performed by the process condition optimization unit 152e will be described. The process condition optimization unit 152e extracts the process conditions of the element processes identified by the element process identification unit 152d from the process condition DB 141d stored in the data storage unit 151, and optimizes the extracted process conditions.

[0088] Fig. 10 is a diagram showing an example of the configuration of the process condition DB 141d. As shown in Fig. 10, the process condition DB 141d associates items such as "process condition 1," "process condition 2," etc. with the item "element process." The example shown in Fig. 10 shows that the process conditions for the element process of "heating" include "heating temperature," "heating time," etc., and the process conditions for the element process of "first finish rolling" include "reduction rate," "roll rotation speed," etc.

[0089] When the element process identified by the element process identifying unit 152d is "first finish rolling," the process condition optimizing unit 152e extracts process conditions such as "reduction rate" and "roll rotation speed" from the process condition DB 141d.

[0090] Next, the process condition optimization unit 152e determines parameters for optimizing the process conditions, such as the "initial value of the process condition," "change range of the process condition," "upper limit of the number of optimization iterations," "optimization method," "necessity of midway termination when the mechanical material reaches the target value," "target value of the mechanical material," etc.

[0091] These parameters may be selected by the user U via the input unit 154. Alternatively, the process condition optimization unit 152e may read out the operation record data 151a of the rolling of the rolled material 4 of the same classification or a similar classification from the data storage unit 151, and determine the parameters for optimization based on the contents of the operation record data 151a. Alternatively, the process condition optimization unit 152e may display the parameters for optimization recorded in the operation record data 151a as candidates on the output unit 155, and allow the user U to select the parameters.

[0092] The parameter can be optimized using a method known in the fields of numerical calculation and machine learning. Specifically, for example, the Nelder-Mead method, the L-BFGS-B method, the Powell method, the Truncated Newton method, the Simulated Annealing method, the Bayesian Optimization method, etc. The procedure of the process condition optimization process by the process condition optimization unit 152e will be described in detail with reference to FIG. 12 described later.

[0093] <Rolling condition determination process> Next, the rolling condition determination process performed by the rolling condition determination unit 152f will be described. The rolling condition determination unit 152f determines rolling conditions including process conditions whose parameters have been optimized by the process condition optimization unit 152e. The rolling condition determination unit 152f displays information indicating the process conditions whose parameters have been optimized on the output unit 155, and receives instructions for rolling conditions based on the displayed content from the user U via the input unit 154.

[0094] The information that the rolling condition determination unit 152f causes to be displayed on the output unit 155 includes an optimization transition graph with the number of repetitions on the horizontal axis and the mechanical material on the vertical axis, a condition-material graph with the process condition on the horizontal axis and the mechanical material on the vertical axis, a table showing the best mechanical material and the process conditions under which it was obtained, and the like.

[0095] The user U can input, via the input unit 154, an instruction to change the rolling conditions from the conditions indicated in the rolling data 141a, an instruction to maintain the rolling conditions indicated in the rolling data 141a, etc. Alternatively, the user U can also give an instruction to return the processing to any one of the processes of the texture feature and mechanical material selection process, the material singular point and reference point selection process, the texture feature selection process, or the element process identification process.

[0096] After the rolling condition determination process by the rolling condition determination unit 152f is completed, the calculation unit 152 transmits the determined rolling conditions to the rolling setting device 11. In addition, the calculation unit 152 stores the contents of a series of rolling setting support processes by each functional unit of the rolling setting support device 15 in the data storage unit 151 as operation record data 151a.

[0097] <Rolling setting support processing by rolling setting support device> Next, the rolling setting support processing by the rolling setting support device 15 according to this embodiment will be described with reference to Fig. 11. Fig. 11 is a flowchart showing an example of the procedure of the rolling setting support processing by the rolling setting support device 15.

[0098] First, the data transmitter / receiver 156 of the rolling setting support device 15 performs rolling data reception processing (step S1). That is, the data transmitter / receiver 156 acquires the rolling data 141a from the data storage device .

[0099] Next, the texture feature quantity and mechanical material calculation unit 152a performs texture feature quantity and mechanical material calculation processing (step S2). Specifically, the texture feature quantity and mechanical material calculation unit 152a calculates the texture feature quantity of the rolled material 4 and the mechanical material of the rolled material 4 at each of at least two or more calculation points set in the longitudinal direction of the rolled material 4. The texture feature quantity of the rolled material 4 is the texture feature quantity during rolling in the hot rolling line 3, and the mechanical material of the rolled material 4 is the mechanical material after it has been cooled to room temperature.

[0100] Next, the material singularity and reference point selector 152b performs a material singularity and reference point selection process (step S3). Specifically, the material singularity and reference point selector 152b selects a material singularity from among a plurality of calculation points set in the rolled material 4 by the structure feature and mechanical material calculation unit 152a, based on information on the deviation amount from the trend line of the mechanical material of the rolled material 4. Then, the material singularity and reference point selector 152b selects, as a reference point, a calculation point that is close to the selected material singularity and has a small amount of deviation from the trend line of the mechanical material.

[0101] Next, the texture feature selection unit 152c performs texture feature selection processing (step S4). Specifically, the texture feature selection unit 152c identifies texture feature values ​​that are the cause of the occurrence of the material singularities identified by the texture feature values ​​and the mechanical material calculation unit 152a. As a result of the texture feature selection processing by the texture feature selection unit 152c, information on the material singularities identified based on information on the mechanical material of the rolled material 4, such as tensile strength, is indicated by the texture feature values. In other words, the material singularities identified based on information on the mechanical material that can only be defined at room temperature are mapped to texture feature values ​​that can also be defined during the rolling process.

[0102] Next, the element process identifying unit 152d performs element process identifying processing (step S5). Specifically, the element process identifying unit 152d identifies the rolling process (element process) in which the difference in mechanical material observed between the material singular point and the reference point occurred, based on the information of the texture feature identified by the texture feature selecting unit 152c.

[0103] Next, the process condition optimization unit 152e performs a process condition optimization process (step S6). Specifically, the process condition optimization unit 152e extracts the process conditions of the element process identified by the element process identification unit 152d from the process condition DB 141d stored in the data storage unit 151, and optimizes the extracted process conditions. The procedure of the process condition optimization process by the process condition optimization unit 152e will be described in detail with reference to the following FIG. 12.

[0104] Next, the rolling condition determination unit 152f performs a process condition determination process (step S7). Specifically, the rolling condition determination unit 152f determines rolling conditions including the process conditions optimized by the process condition optimization unit 152e.

[0105] After the process of step S7, if the user U inputs an instruction to return to any of steps S3 to S6 and perform the process, the calculation unit 152 performs the process of the selected step.

[0106] Next, the calculation unit 152 performs a termination process (step S8). In step S8, the calculation unit 152 transmits the rolling conditions determined in step S7 to the rolling setting device 11, and stores the contents of a series of rolling setting support processes in the data storage unit 151 as operation record data 151a.

[0107] (Process condition optimization processing) Next, the process condition optimization process performed by the process condition optimization unit 152e in step S6 of Fig. 11 will be described with reference to Fig. 12. Fig. 12 is a flowchart showing an example of the procedure of the process condition optimization process.

[0108] First, the process condition optimization unit 152e creates calculational rolling conditions by setting the optimized process conditions as initial values ​​of the process conditions and setting the process conditions of other elemental processes to the process conditions described in the rolling data 141a (step S11). Next, the process condition optimization unit 152e calculates the structure feature amount of the rolled material 4 in the rolling process and the mechanical property value of the rolled material 4 at room temperature, for each calculation point set in step S2 of Fig. 11, based on the calculational rolling conditions created in step S11. Then, the process condition optimization unit 152e stores the calculated information on the structure feature amount and mechanical property value of the rolled material 4 in the memory 153 (see Fig. 2) or the like (step S12).

[0109] The calculation of the structure feature amount and the mechanical material quality of the rolled material 4 in step S12 can be performed by a method similar to the structure feature amount and mechanical material quality calculation process in step S2 of Fig. 11. Alternatively, the process condition optimization unit 152e may calculate the structure feature amount and the mechanical material quality of the rolled material 4 using only the material singular points and reference points as targets. Alternatively, the process condition optimization unit 152e may calculate the structure feature amount and the mechanical material quality of the rolled material 4 using a thinned-out number of calculation points including the material singular points and reference points as targets.

[0110] Next, the process condition optimization unit 152e determines whether the number of repetitions of the optimization process has reached a preset upper limit (step S13). If it is determined in step S13 that the upper limit has been reached (YES in step S13), the process condition optimization process by the process condition optimization unit 152e ends.

[0111] On the other hand, if it is determined in step S13 that the upper limit has not been reached (NO in step S13), the process condition optimization unit 152e determines whether an instruction to terminate the process has been given by the user U (step S14). If it is determined in step S14 that an instruction to terminate the process has been given (YES in step S14), the process condition optimization unit 152e determines whether the mechanical properties calculated in step S12 satisfy the target values ​​(step S15). If it is determined in step S15 that the target values ​​have been satisfied (YES in step S15), the process condition optimization unit 152e ends the process condition optimization process.

[0112] On the other hand, if it is determined in step S15 that the mechanical properties do not satisfy the target values ​​(NO in step S15), or if the determination in step S14 is NO, the process condition optimization unit 152e updates the process conditions using the optimization parameters selected by the process condition optimization unit 152e to create calculation rolling conditions (step S16). Next, the process condition optimization unit 152e returns to step S12 to continue the process.

[0113] In the above-described embodiment, the material singularity and reference point selection unit 152b detects material singularities, which are locations where mechanical material singularities occur in the longitudinal direction of the rolled material 4 that is the target of rolling condition setting support in the hot rolling line 3. Furthermore, the texture feature selection unit 152c selects texture features of the rolled material that are highly correlated with the mechanical material in which the material singularity was detected. Furthermore, the element process identification unit 152d identifies an element process of the hot rolling line 3 where a mechanical material singularity has occurred, based on information about the texture feature selected by the texture feature selection unit 152c. Furthermore, the process condition optimization unit 152e optimizes the process conditions for the element process identified by the element process identification unit 152d. Therefore, according to this embodiment, it is possible to appropriately select and optimize rolling process conditions that should be optimized to enable the production of a rolled material 4 having desired mechanical properties.

[0114] Furthermore, in the above-described embodiment, the mechanical material used by the material singularity and reference point selection unit 152b for detecting material singularities is the mechanical material of the rolled material at room temperature, and the structure feature selected by the structure feature selection unit 152c is the structure feature of the rolled material 4 in the hot rolling line 3. In other words, a material singularity identified based on information about the mechanical material that can be defined only at room temperature is mapped to a structure feature that can be defined even during the rolling process. Therefore, according to this embodiment, it is possible to identify an element process in which a peculiar material has occurred in the rolling process, without newly constructing a calculation model or the like for calculating the mechanical material in the rolling process.

[0115] In the above-described first embodiment, an example has been given in which the material singularity and reference point selection unit 152b selects material singularities and reference points for one rolled material 4. However, the present invention is not limited to this. The material singularity and reference point selection unit 152b may select material singularities and reference points by comparing the mechanical material properties and structure feature amounts in a plurality of rolled materials 4.

[0116] 13 is a graph showing the distribution of tensile strength in the longitudinal direction of the rolled material 4, which is referred to by the material singularity and reference point selection unit 152b when selecting material singularities and reference points from a plurality of rolled materials 4. The information indicated by the vertical and horizontal axes of the graph shown in FIG. 13 is the same as that in the graph shown in FIG. 5, and therefore a description thereof will be omitted.

[0117] The graph shown in Figure 13 displays information on the mechanical properties of the rolled material 4 (hereinafter referred to as the "target material") that is the target of support for setting rolling conditions, as well as information on the mechanical properties of a rolled material (hereinafter referred to as the "reference material") that belongs to the same or similar classification as the target material and has good mechanical properties.

[0118] 13, the calculation points set for the target material are indicated by black circles, and the calculation points set for the reference material are indicated by white circles. The material singularity and reference point selector 152b selects the material singularity point Pu1 from the calculation points of the target material. Furthermore, the material singularity and reference point selector 152b selects the reference point Pr1 from the calculation points of the reference material that belongs to the same or a similar classification as the target material and has good mechanical properties. Therefore, it is expected that the distance between the material singularity point Pu1 and the reference point Pr1 in the longitudinal direction of the rolled material 4 will be shorter than the distance between the material singularity point Pu and the reference point Pr calculated in the first embodiment described above.

[0119] Because the rolled material 4 is rolled sequentially from the leading edge to the tail edge in the longitudinal direction, calculation points close to the leading edge of the rolled material 4 are rolled at a relatively high temperature, while calculation points close to the tail edge are rolled at a relatively low temperature. Therefore, if the distance between the material singularity and the reference point in the longitudinal direction of the rolled material 4 becomes long, a difference in the waiting time before rolling occurs between the positions of the material singularity and the reference point. The cooling that occurs during this difference in time results in a temperature difference between the calculation points. Furthermore, if "accelerated rolling" is performed to reduce this temperature difference, the rolling speed increases closer to the tail edge. This results in a difference in the rolling speed depending on the length of the waiting time. Furthermore, if the rolling temperature and rolling speed change, structural characteristics such as the average austenite grain size also change, ultimately affecting the mechanical properties of the rolled material 4.

[0120] In contrast to this, according to the modified example, the distance between the material singular point Pu1 and the reference point Pr1 can be shortened, thereby reducing the difference in waiting time that occurs along the longitudinal direction of the rolled material 4. In other words, according to the modified example, the influence of the difference in waiting time on the mechanical quality of the rolled material 4 can be reduced, and therefore it becomes possible to appropriately evaluate the influence of the rolling conditions that can be set by the rolling setting support device 15.

[0121] 2. Second embodiment Next, a second embodiment of the present invention will be described with reference to Fig. 14. Fig. 14 is a block diagram showing an example of the configuration of a hot rolling system 100A according to the second embodiment. The hot rolling system 100A shown in Fig. 14 differs from the hot rolling system 100 shown in Fig. 1 in that a rolling setting support device 15 is provided outside the rolling control system 1A.

[0122] The rolling setting support device 15 can be installed, for example, inside the building where the rolling control system 1A is installed, in another building on the same premises as the building, or in a remote location.

[0123] The rolling setting support device 15 according to this embodiment receives rolling data 141a from the rolling control system 1A via electric communication, and transmits the determined rolling conditions to the rolling control system 1A via electric communication. A user U may operate the rolling setting support device 15 at the location where the device is installed, or may operate the rolling setting support device 15 from another location via electric communication.

[0124] According to this embodiment, it is possible to support rolling settings of a plurality of hot rolling lines 3 using one rolling setting support device 15. For example, in a configuration in which one company operates hot rolling lines 3 at a plurality of locations, it is possible to support settings of the plurality of hot rolling lines 3 from one rolling setting support device 15. Therefore, compared to a case in which a rolling setting support device 15 is provided for each rolling control system 1, equipment costs can be reduced.

[0125] Moreover, in this embodiment, one rolling setting support device 15 can accumulate operation record data 151a (see FIG. 2) for each of the multiple hot rolling lines 3. Therefore, according to this embodiment, the quality of process condition optimization by the rolling setting support device 15 can also be improved. Furthermore, by reducing the number of rolling setting support devices 15, it becomes possible to assign experts with knowledge in the relevant field as operators of the rolling setting support devices 15. In this case, a further improvement in the quality of process condition optimization can be expected.

[0126] It should be noted that the above-described embodiments have described the system configuration in detail and specifically to clearly explain the present invention, and are not necessarily limited to those having all of the described configurations. In Figures 1, 2, and 14, the control lines or information lines indicated by solid lines or arrows indicate those considered necessary for explanation, and do not necessarily represent all of the control lines or information lines in the product. In reality, it can be considered that almost all of the configurations are interconnected.

[0127] Furthermore, in this specification, processing steps describing chronological processing include not only processing that is performed chronologically in the order described, but also processing that is not necessarily performed chronologically but is performed in parallel or individually (for example, parallel processing or processing by objects). [Explanation of symbols]

[0128] 1, 1A...rolling control system, 3...hot rolling line, 4...rolled material, 11...rolling setting device, 12...rolling control device, 14...data storage device, 15...rolling setting support device, 100, 100A...hot rolling system, 141a...rolling data, 141b...metallurgical model, 141c...structural feature causal relationship DB, 141d...process condition DB, 151...data storage unit, 151a...operation record data, 152...calculation unit, 152a...mechanical material calculation unit, 152b...reference point Selection unit, 152c...structure feature quantity selection unit, 152d...element process identification unit, 152e...process condition optimization unit, 152f...rolling condition determination unit, 154...input unit, 155...output unit, 310...heating furnace, 311...transport line, 312...roughing mill, 314...finishing mill, 315...cooling device, 316...winder, 320...roughing mill entrance thermometer, 321...roughing mill exit thermometer, 322...finishing mill entrance thermometer, 323...finishing mill exit thermometer, 324...winder entrance thermometer

Claims

1. a material singularity detection unit that detects material singularities, which are locations where mechanical material singularities occur in the longitudinal direction of a rolled material that is an object of support for setting rolling conditions in a hot rolling line; a structure feature quantity selection unit that selects a structure feature quantity of the rolled material that has a high correlation with the mechanical material property in which the material singularity has been detected; an element process identifying unit that identifies an element process of the hot rolling line in which the mechanical material anomaly has occurred, based on information on the structure feature selected by the structure feature selecting unit; a process condition optimization unit that optimizes the process conditions in the element process identified by the element process identification unit. Rolling setting support device.

2. The mechanical material used by the material singularity detection unit to detect the material singularity is the mechanical material of the rolled material at room temperature. The rolling setting support device according to claim 1.

3. a structure feature amount and mechanical material calculation unit that sets calculation points at a plurality of different positions in the longitudinal direction of the rolled material and calculates the structure feature amount and the mechanical material amount at the plurality of calculation points, The material singularity detection unit sets the calculation point having a large deviation amount from the mechanical material trend line obtained from conventional data of rolled materials belonging to the same or similar classification as the rolled material for which setting of rolling conditions is to be supported as the material singularity. The rolling setting support device according to claim 2.

4. the material singularity detection unit sets the calculation point, which has a small deviation from the trend line and is located close to the material singularity in the longitudinal direction of the rolled material, as a reference point; The element process identification unit calculates a difference value obtained by subtracting the texture feature amount at the reference point from the texture feature amount at the material singular point for each element process, and identifies an element process in which the difference value has changed by a predetermined amount or more from the previous element process as an element process in which the mechanical material singularity has occurred. The rolling setting support device according to claim 3.

5. The tissue feature selection unit selects the tissue feature using the magnitude of the absolute value of the correlation coefficient with the mechanical material and information indicating a causal relationship between the tissue feature values. The rolling setting support device according to claim 4.

6. The material singularity detection unit selects the material singularity from among the plurality of calculation points set for the rolled material for which rolling condition setting support is to be provided, and sets the calculation point closest to the position of the material singularity as a reference point from among a plurality of calculation points set for rolled material that belongs to the same or similar classification as the rolled material for which rolling condition setting support is to be provided and has good mechanical properties. The rolling setting support device according to claim 3.

7. the structural feature amount includes at least one of a ratio of austenite, a ratio of ferrite, a ratio of pearlite, a ratio of bainite, a ratio of martensite, an average crystal grain size of austenite, an average crystal grain size of ferrite, a lamellar spacing of pearlite, a lath size of bainite, a lath width of martensite, a packet size of martensite, and a block size of martensite, all of which are included in the rolled material; The mechanical properties include at least one of the yield strength, tensile strength, elongation, and hardness of the rolled material. The rolling setting support device according to any one of claims 1 to 6.

8. a step in which a material singularity detection unit detects a material singularity, which is a location where a mechanical material singularity occurs in the longitudinal direction of a rolled material that is a target for supporting setting of rolling conditions in a hot rolling line; a step in which a structure feature selection unit selects a structure feature of the rolled material that has a high correlation with the mechanical material in which the material singularity has been detected; an element process identifying unit identifying an element process of the hot rolling line in which the mechanical material anomaly has occurred, based on information on the structure feature selected by the structure feature selecting unit; and a step of optimizing the process conditions in the element process identified by the element process identifying unit by a process condition optimizing unit. Rolling setting support method.

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