JP5126763B2 - Extraction pitch prediction method for continuous furnace - Google Patents

Description

  The present invention relates to a method for predicting a steel piece extraction pitch in a continuous heating furnace, a continuous heating furnace including means for executing the extraction pitch prediction method, a method for operating the continuous heating furnace, and manufacturing a steel material including the operation method. Regarding the method. More specifically, the present invention relates to an extraction pitch prediction method for a continuous heating furnace, a continuous heating furnace, a method for operating a continuous heating furnace, and a method for manufacturing a steel material, which can improve the quality of a steel product.

  In the heating operation of a continuous heating furnace (hereinafter sometimes referred to as a “furnace”), the time at which the charged steel slab is extracted immediately after the steel slab as the material to be heated is charged into the furnace. Therefore, it is possible to reduce the change in the extraction schedule due to excessive or insufficient baking. If the correction of the extraction pitch that disturbs the initial operation schedule can be reduced, it is possible to improve the quality of the charged steel slab and reduce the fuel consumption rate, and further reduce the judgment work of the field worker. Therefore, it is very important to improve the accuracy of prediction of the extraction pitch of the continuous heating furnace.

Until now, several techniques for accurately predicting both the heating capacity of a continuous heating furnace and the rolling capacity in a rolling process have been disclosed. For example, Patent Document 1 discloses a technique related to a method for predicting an extraction pitch of a continuous heating furnace. In this technique, a first means for searching a past performance example and predicting a rolling pitch at the maximum rolling capacity is disclosed. The second means for calculating the heating pitch at the maximum heating capacity of the continuous heating furnace from the material information of the charged steel slab, and the third means for predicting the downtime such as roll change in the rolling process, The maximum value among the obtained pitches is determined as the extraction pitch of the continuous heating furnace.
JP-A-6-330151

  In the technique disclosed in Patent Document 1, when the extraction pitch of the steel slab is determined, the rolling pitch of the rolling process at the time of determination is not considered. However, in actual operation, even when the steel slab is not heated, the rolling pitch is lowered (for example, rolling pitch down due to troubles in the finishing line, etc.). Sometimes called "pitch down.") Even in such a case, the technique of Patent Document 1 determines the extraction pitch without considering the actual rolling pitch, and thus there is a problem that a large error is likely to occur between the determined extraction pitch and the actual result. It was. This error increases as the number of steel slabs extracted at a pitch different from the actual result increases, and therefore, the error tends to increase as the rolling pitch decreases and the operation time increases. When an error occurs in the extraction pitch, an error also occurs in the in-furnace time of the steel slab, so that the technique of Patent Document 1 has a problem that the quality of the product steel material is likely to be reduced.

  Therefore, the present invention provides an extraction pitch prediction method for a continuous heating furnace, a continuous heating furnace, a method for operating a continuous heating furnace, and a method for manufacturing a steel material that can improve the quality of the product steel material. This is the issue.

  The present invention will be described below. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiments.

1st this invention predicts the pitch which extracts the steel slab (1, 2, 3, 4, ...) rolled by a rolling process (90) from a continuous heating furnace (100), It is an extraction pitch prediction method, and based on the material information of the steel slab charged into the continuous heating furnace (100), the steel slab in the continuous heating furnace (100) Rolling pitch prediction for predicting the rolling pitch P1 at the time of the maximum rolling capacity in the rolling step (90) based on the first operation step (S2) and the past operation results divided into the group B other than the group A. In the heating pitch prediction step (S5) and the rolling step (90) for calculating the heating pitch P2 when the heating capacity of the continuous heating furnace (100) is maximum based on the step (S4) and the material information of the steel slab. Predict the downtime, and billets (1, 2, 3, ...) before the downtime It computes the extracted pitch P3 for extracting, extracting pitch prediction step and (S6, S9), P1, P2, and compares the P3, a first comparing step of selecting a minimum pitch Px (S7), comparing the current and the rolling pitch P4 and P3 in the rolling step (90), and a second comparison step of selecting a minimum pitch Py (S11), provided with the Py, billet group a (1,1 ,...), And Px is the extraction pitch of the steel slabs of group B (2, 3, 4,...). Solve.

  Here, “material information of a steel slab” means information on a steel slab determined according to the steel type, such as finishing thickness, finishing width, finishing temperature, and the like. Further, as a specific determination method of the most outer group A, since the rolling pitch varies depending on the steel type, first, each steel slab in the continuous heating furnace (100) is converted into each steel type using the material information of the steel slab. After that, the steel grades are examined in order from the outermost side of the continuous heating furnace (100), and the same steel grade as the steel grade present closest to the outlet in the furnace and / or equivalent to the steel grade. A method such as designating a group A as a steel type that can be rolled at a rolling pitch can be given. In addition, as a specific example of the “pause time in the rolling step (90)”, a roll change time and the like can be given. Furthermore, the values of P1, P2, P3, and P4 may be different for each steel type (or for each group). That is, the values of Px and Py may differ for each steel type (or for each group).

  In the first aspect of the present invention, the group A steel pieces (1, 1,..., 1a, 1a,...) Exist in the continuous heating furnace (100) (hereinafter referred to as “in-furnace time”). The time T defining step (S12) for defining the time T for correcting the prediction error of) and the steel pieces (1, 1,..., 1a, 1a,...) Of group A are extracted within the time T. And a second sorting step (S13) that divides the group A1 into a group A2 other than the group A1, and the extraction pitch of the steel pieces (1, 1,...) Of the group A1. And Px is preferably the extraction pitch of the steel pieces (1a, 1a,...) Of group A2.

  Here, the “time T for correcting the prediction error of the in-furnace time” is the case where the value of P4 is decreased due to the pitch down operation, and the normal operation is restored and the value of P4 is restored. Even when the value becomes large, it is a time defined for accurately predicting the in-furnace time of the steel pieces (1, 1,..., 1a, 1a,...) Of group A. The said time T can be prescribed | regulated based on the past operation performance, for example, average pitch down time (45 minutes, 60 minutes etc.) can be prescribed | regulated as the time T. And the group A steel pieces (1, 1,...) That can be extracted within the time T are group A1, and the group A steel pieces (1a, 1a,...) That cannot be extracted within the time T are group A2. Respectively. The same applies to the following inventions.

  2nd this invention is a continuous heating furnace (100) from which the steel slab (1, 2, 3, 4, ...) rolled in a rolling process (90) is extracted, Comprising: Steel charged Based on the material information of the piece, the first sorting means (21) capable of sorting the steel piece into the group A located on the outermost side and the group B other than the group A, and past operation results Based on the above, the rolling pitch predicting means (21) capable of predicting the rolling pitch P1 at the maximum rolling capacity of the rolling step (90) and the heating pitch P2 at the maximum heating capacity are calculated based on the material information of the steel slab. Possible heating pitch predicting means (21), predicting the downtime in the rolling process, and calculating the extraction pitch P3 for extracting the steel pieces (1, 2, 3, ...) by the downtime, Extraction pitch prediction means (21) and current rolling speed in the rolling step (90) And calculating means (21) capable of calculating the rolling pitch P4 from the first and comparing means (21) capable of determining the magnitude relationship by comparing the values of P1, P2, P3, and P4. The above-mentioned problem is solved by a continuous heating furnace (100) characterized by the following.

  In the second aspect of the present invention, the time T for correcting the prediction error of the time that the steel pieces (1, 1,..., 1a, 1a,...) Of the group A exist in the continuous heating furnace (100) is further set. Time T defining means (21) and group A steel pieces (1, 1,..., 1a, 1a,...) That can be defined are extracted within time T and group A2 other than group A1. And a second sorting means (21) capable of sorting.

3rd this invention is an operating method of the continuous heating furnace (100) from which the steel slab (1, 2, 3, 4, ...) rolled in a rolling process (90) is extracted, Comprising: Continuous heating Based on the material information of the steel slab charged into the furnace (100), the steel slab in the continuous heating furnace (100) is divided into the outermost group A and a group B other than the group A. The rolling pitch prediction step (S4) for predicting the rolling pitch P1 when the rolling capacity is maximum in the rolling step (90) based on the first sorting step (S2) and the past operation results, and the material of the steel slab Based on the information, the heating pitch prediction step (S5) for calculating the heating pitch P2 at the maximum heating capacity of the continuous heating furnace is predicted, and the downtime in the rolling step (90) is predicted, and the steel slab is reached by the downtime Calculating an extraction pitch P3 for extracting (1, 2, 3,...), And output pitch prediction step (S6, S9), P1, P2, and compares the P3, a first comparing step of selecting a minimum pitch Px (S7), the current rolling pitch in the rolling step (90) P4 and comparing the P3, a second comparison step of selecting a minimum pitch Py (S11), comprising a steel strip of the group a (1,1, ...), and extracted with the Py, group B The above-mentioned problems are solved by a method of operating a continuous heating furnace characterized in that the steel pieces (2, 3, 4,...) Are extracted and operated with the Px.

  In the third aspect of the present invention, the time T for correcting the prediction error of the time when the steel pieces (1, 1,..., 1a, 1a,...) Of the group A exist in the continuous heating furnace (100) is further set. The time T defining step (S12) to be defined, and the group A steel pieces (1, 1,..., 1a, 1a,...) Are extracted within the time T, and the group A2 other than the group A1 And a second sorting step (S13). The steel pieces (1, 1,...) Of group A1 are extracted with Py, and the steel pieces (1a, 1a,...) Of group A2 are extracted. It is preferable to extract and operate with Px.

  4th this invention solves the said subject by the manufacturing method of the steel materials characterized by including the operating method of the continuous heating furnace concerning the said 3rd this invention.

  Here, the method for producing a steel material according to the fourth aspect of the present invention includes at least a heating process using a continuous heating furnace and a rolling process capable of rolling a steel piece extracted from the continuous heating furnace. Other steps that can be provided are not particularly limited. Specific examples of the other steps include a refining step and a heat treatment step. Moreover, as a specific example of the steel material manufactured by this invention, a steel plate, a shape steel, a steel pipe, etc. can be mentioned.

  According to the first aspect of the present invention, the billets of the continuous heating furnace (100) are grouped, and the extraction pitch of the outermost group A is determined in consideration of the current rolling pitch P4 in the rolling step (90). Is done. Therefore, according to the first aspect of the present invention, while suppressing an increase in processing time when determining the extraction pitch of the steel slab, the error between the determined extraction pitch and the actual result, and the in-furnace time of the steel slab Since the error can be reduced, it is possible to provide an extraction pitch prediction method for a continuous heating furnace that can improve the quality of the product steel material.

  Furthermore, in the first aspect of the present invention, the outermost group A of the continuous heating furnace (100) is grouped, and the extraction pitch of the steel pieces (1a, 1a,...) Of the group A2 that are not extracted within the time T is Px. Then, after the elapse of time T, the steel pieces (1a, 1a,...) Of group A2 can be extracted with the pitch Px. In this way, it is possible to reduce the error in the in-furnace time caused by the extraction pitch at time T being continued even after time T has elapsed. Therefore, if it is set as this structure, the extraction pitch prediction method of the continuous heating furnace which can suppress the quality fall of the product steel materials resulting from pitch down can be provided.

  According to the second aspect of the present invention, the steel slabs in the continuous heating furnace (100) can be grouped, and the extraction pitch of the outermost group A is set to the current rolling pitch P4 in the rolling step (90). It can be determined in consideration. Therefore, according to the second aspect of the present invention, since the error between the determined extraction pitch and the actual result and the error in the in-furnace time of the steel slab can be reduced, the continuous heating furnace that can improve the quality of the product steel material ( 100).

  Furthermore, in the second aspect of the present invention, the outermost group A of the continuous heating furnace (100) is grouped, and the extraction pitch of the steel pieces (1a, 1a,...) Of the group A2 that are not extracted within the time T is Px. Then, after the elapse of time T, the steel pieces (1a, 1a,...) Of group A2 can be extracted with the pitch Px. In this way, it is possible to reduce the error in the in-furnace time caused by the extraction pitch at time T being continued even after time T has elapsed. Therefore, if it is set as this structure, the continuous heating furnace (100) which can suppress the quality fall of the product steel materials resulting from pitch down can be provided.

  According to the third aspect of the present invention, the steel slabs of the continuous heating furnace (100) are grouped, and the extraction pitch of the outermost group A is determined in consideration of the current rolling pitch P4 in the rolling process. Therefore, according to the first aspect of the present invention, since the error between the determined extraction pitch and the actual result and the error in the in-furnace time of the steel slab can be reduced, the continuous heating furnace capable of improving the quality of the product steel material Can provide operation method.

  Furthermore, in the third aspect of the present invention, the outermost group A of the continuous heating furnace (100) is grouped, and the extraction pitch of the steel pieces (1a, 1a,...) Of the group A2 that are not extracted within the time T is Px. Then, after the elapse of time T, the steel pieces (1a, 1a,...) Of group A2 can be extracted with the pitch Px. In this way, it is possible to reduce the error in the in-furnace time caused by the extraction pitch at time T being continued even after time T has elapsed. Therefore, if it is set as this structure, the operation method of the continuous heating furnace which can suppress the quality fall of the product steel materials resulting from pitch down can be provided.

  According to the fourth aspect of the present invention, an error in the in-furnace time of the steel slab in the continuous heating furnace can be reduced, so that it is possible to provide a method for manufacturing a steel material capable of suppressing a deterioration in quality of the product steel material.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The illustrated form is merely an example, and the present invention is not limited to the illustrated form.

1. Extraction Pitch Prediction Method for Continuous Heating Furnace A flow chart (embodiment example) of an extraction pitch prediction method for a continuous heating furnace according to the present invention is schematically shown in FIG. As shown in FIG. 1, in the extraction pitch prediction method for a continuous heating furnace of the present invention (hereinafter simply referred to as “prediction method”), firstly, information such as billet material information and rolling process downtime is obtained. Based on the material information of the steel slab, the in-furnace steel slab is divided into a group A and a group B (first selection process S2). Thereafter, in step S3, it is determined whether or not the in-furnace steel slab belongs to the group A. If a negative determination is made in step S3, the rolling pitch P1 at the time of the maximum rolling capacity of the rolling process of the steel slabs related to group B is predicted based on the past operation results (rolling pitch prediction step S4) and related to group B. Based on the material information of the billet, the heating pitch P2 at the maximum heating capacity of the furnace is calculated (heating pitch prediction step S5), and the downtime in the rolling process is predicted and the billet in the furnace is replaced by the downtime. An extraction pitch P3 for extraction is calculated (extraction pitch prediction step S6). In this way, P1, P2, and, P3 when is derived, the P1, P2, P3 and compare with minimum pitch is certified Px (first comparison step S7), billet Group B The extraction pitch is determined to be Px (step S8).

If an affirmative determination is made in step S3, an outage time in the rolling process is predicted, and an extraction pitch P3 for extracting the steel slab in the furnace is calculated by the outage time (extraction pitch prediction step S9). The current rolling pitch P4 in the steel slab rolling process is calculated (P4 calculating process S10). In this way, when P3 and P4 are calculated, the pitch of the lesser compares the P3 and P4 are certified Py (second comparison step S11). When the current rolling pitch is a pitch during normal operation, or when steps S12 to S16 described later are not performed, the extraction pitch of the steel pieces of group A is determined as Py in this way.

  On the other hand, it is preferable to improve the prediction accuracy of the extracted pitch even when the pitch is down from the viewpoint of preventing the quality deterioration of the manufactured steel material due to the pitch down. From this point of view, in the prediction method of the form shown in FIG. 1, a time T for correcting the prediction error of the in-furnace time of the billet related to group A is further defined based on the past operation results (time T defining step S12). And the steel slab of group A is sorted into group A1 extracted within the time T and group A2 not extracted (second sorting step S13), and whether the steel slab of group A belongs to group A1 or not. Is determined (step S14). The steel piece for which a negative determination is made in step S14 belongs to group A2, and the steel piece belonging to group A2 is extracted after the elapse of time T. Therefore, in order to reduce the error in the in-furnace time, the extraction pitch of the steel pieces of group A2 is determined as Px (step S15). On the other hand, the steel pieces that have been affirmed in step S14 belong to group A1, and the steel pieces that belong to group A1 are extracted within time T. Therefore, the extraction pitch of the steel pieces of group A1 is determined as the rolling pitch Py (step S16). After the step, it is determined whether or not the calculation has been performed for all the steel pieces (step S17). If a negative determination is made in step S17, there remains a steel slab whose extraction pitch has not been determined, and therefore the process returns to step S3 to determine the extraction pitch of the steel slab. If an affirmative determination is made in step S17, the extraction pitch prediction process is completed because the extraction pitches of all the steel pieces have been determined.

2. Operation method of continuous heating furnace FIG. 2 is a conceptual diagram of the group division method. The right side of FIG. 2 is the exit side of the continuous heating furnace, and the left side is the entrance side of the continuous heating furnace. The numerical value in each billet in FIG. 2 indicates the extraction pitch [sheet / hour] of the group to which the billet belongs. Here, in the group B, the extraction pitch of the steel slabs 2, 2,... Is 20 [sheets / hour], whereas the extraction pitch of the steel slabs 3, 3,. Sheet / hour]. This indicates that the steel slabs 2, 2, ... and the steel slabs 3, 3, ... 4, 4, ... have different steel types, and the Px values determined according to the respective steel types are different. Yes.

The steel slabs existing in the furnace are divided into the outermost group A and the group B other than the outermost group based on the material information of the charged steel slabs. Steel pieces 2 groups B, ... are extracted in the steel pieces 2, the P1 determined according to ... steels, P2, P3 of the minimum pitch (20 [sheets / hour]). Further, the steel strip 3,3, Group B ..., 4,4, ... is the steel pieces 3,3, ..., 4,4, ... of the minimum of the P1, P2, P3 determined according to the steel type It is extracted at a pitch (10 [sheets / hour]). In contrast, steel strips 1,1 of the group A, ... is extracted with minimum pitch of the P3, P4 (15 [sheets / hour]).

  In the said group division method, the conceptual diagram of the group division method in case all the steel slabs of the outermost group A are not extracted within the regulation time T is shown in FIG. The right side of FIG. 3 is the exit side of the continuous heating furnace, and the left side is the entrance side of the continuous heating furnace. In FIG. 3, FIG. 3 (a) shows a state before the group A is subdivided, FIG. (B) schematically shows the state after group A has been subdivided. In addition, the numerical value in each steel slab in FIG. 3 has shown the extraction pitch [sheet / time] of the group to which the said steel slab belongs.

As shown in FIG. 3, when all the steel pieces of the outermost group A are not extracted during the time T, the outermost group A is further divided into a group A1 made of steel pieces extracted within the time T. And subdivided into a group A2 made of steel pieces that are not extracted within time T. Then, the steel strip 1, 1 a group A1, ... is extracted with minimum pitch (15 [sheets / hour]) of the P3, P4, billet 1a Group A2, 1a, ... is the steel strip 1a , 1a, is extracted ... the minimum pitch of the P1, P2, P3 determined according to steel grade (= 20 [sheets / hour]). If it does in this way, it will become possible to set the extraction pitch of the steel slabs 1a, 1a,... After the elapse of time T to a pitch different from the extraction pitch at time T (= 15 [sheets / hour]). Even after the elapse of the time T, the error in the in-furnace time caused by the extraction of the steel slab at the pitch at the time T can be reduced, and the quality of the manufactured steel material can be improved.

3. Continuous Heating Furnace FIG. 4 schematically shows an embodiment of the continuous heating furnace according to the present invention. It is assumed that a steel slab / steel material (not shown in FIG. 4) advances from the left side to the right side in FIG. For the continuous heating furnace of the present invention, the extraction pitch prediction method for the continuous heating furnace and the operation method for the continuous heating furnace can be applied.
As shown in FIG. 4, the continuous heating furnace 100 of the present invention detects the rolling speed in the rolling process 90, the furnace 10, the control device 20 that can control the extraction pitch of the steel slab extracted from the furnace 10. Possible detection means 15. The steel slab extracted from the continuous heating furnace 100 is then wound up by, for example, a winding device 92 through a rolling step 90 or the like by rolling mills 91 and 91 or the like.

  The extraction pitch of the steel pieces extracted from the furnace 10 is controlled by the control device 20. The control device 20 is provided with a CPU 21 that executes extraction pitch prediction processing, processing related to billet grouping, and the like, and a storage device for the CPU 21. The CPU 21 is configured by combining a microprocessor unit and various peripheral circuits necessary for the operation thereof, and a storage device for the CPU 21 includes, for example, a ROM 22 for storing programs and various data necessary for predicting an extraction pitch of a steel piece, It is configured by combining a RAM 23 or the like that functions as a work area for the CPU 21. In addition to the configuration, the control device 20 in the continuous heating furnace 100 of the present invention functions by combining the CPU 21 with software or the like stored in the ROM 22.

  Input information such as material information of the steel slab charged into the furnace 10, downtime, and an output signal from the detection means 15 reach the CPU 21 as an input signal via the input port 24. The CPU 21 controls a steel piece extraction pitch operation command to the furnace 10 through the output port 25 based on the input signal and the program stored in the ROM 22. Here, specific examples of the data stored in the ROM 22 include data relating to past operation results of the rolling process, data relating to the heating capacity for each steel type, and the like. Moreover, as a specific example of the program memorize | stored in ROM22, it is based on the calculation program used when predicting the rolling pitch P1 at the time of the rolling capability maximum of a rolling process based on the past operation performance, and the material information of a steel slab. A calculation program used when calculating the heating pitch P2 when the heating capacity is maximum, a calculation program used when calculating the extraction pitch P3 for extracting the steel slab before the downtime, the detection means 15 and A calculation program used to calculate the current rolling pitch P4 based on data transmitted through the input port 24, a program used to group steel slabs in the furnace 10, and pitches P1 and P2 , P3, and a program used when judging the magnitude relationship of P4. That is, in the continuous heating furnace 100 of the form shown in FIG. 4, the CPU 21 has first selection means, rolling pitch prediction means, heating pitch prediction means, extraction pitch prediction means, calculation means, first comparison means, time T It functions as a defining means and a second sorting means.

  In the above description regarding the continuous heating furnace of the present invention, the first sorting means, rolling pitch prediction means, heating pitch prediction means, extraction pitch prediction means, detection means, first comparison means, time T defining means, and The embodiment in which the CPU 21 functioning as the second sorting means is illustrated, but the continuous heating furnace of the present invention is not limited to the embodiment. Each of the above functions provided in the CPU 21 according to the embodiment shown in FIG. 4 may be provided in a plurality of processing devices and the like.

  An embodiment in which an automatic furnace model is applied to the continuous heating furnace of the present invention will be described below.

  FIG. 5 shows a schematic diagram of the automatic furnace operation model. The automatic furnace model shown in FIG. 5 includes an input unit 51, a target extraction temperature calculation unit 52, an extraction pitch calculation unit 53, an in-furnace time prediction calculation unit 54, an extraction temperature prediction calculation unit 55, and a set furnace temperature calculation unit 56. . The target extraction temperature calculation unit 52 determines the target extraction temperature of the steel slab extracted from the continuous heating furnace, and the extraction pitch calculation unit 53 calculates the extraction pitch (Px, Py, etc.) of each steel slab. Is done. Further, the in-furnace time prediction calculation unit 54 predicts the in-furnace time of the steel slab, and the extraction temperature prediction calculation unit 55 predicts the in-furnace time prediction calculation unit 54 after the in-furnace time has elapsed. The temperature of the piece is predicted. Then, using the extraction temperature predicted by the extraction temperature prediction calculation unit 55 and the target extraction temperature calculated by the target extraction temperature calculation unit 52, the set furnace temperature calculation unit 56 converts the steel slab into the target extraction temperature. The optimum furnace temperature for the extraction is calculated.

  In the above prediction calculation performed in the automatic furnace model, the prediction accuracy of the extraction pitch used when predicting the in-furnace time greatly affects the accuracy of the optimum furnace temperature, the quality of the charged billet, the fuel consumption rate, etc. Therefore, it is desired to improve the extraction pitch prediction accuracy. And according to this invention, since the data regarding the present rolling pitch can be reflected in calculation of extraction pitch, it becomes possible to aim at the high precision of extraction pitch prediction precision.

FIG. 6 shows an overview of the in-furnace time prediction method. The numerical value in each billet shown in FIG. 6 indicates the extraction pitch [sheet / time] of the group to which the billet belongs.
When predicting the in-furnace time, the unit of the extraction pitch obtained by the above calculation is converted from [sheet / hour] to [minute / sheet]. For example, when the extraction pitch is 20 [sheets / hour], it can be converted to 60/20 = 3 [minutes / sheet]. Thus, the conversion time is estimated for all the steel slabs, and the in-furnace time is predicted by adding all the extraction pitches of all the steel slabs extracted before the target material whose in-furnace time is predicted. be able to. In FIG. 6, the steel piece first extracted after the lapse of the downtime is the target material 4x whose in-furnace time is predicted. The extraction pitch of group A steel slabs 1, 1,... Is 15 [sheets / hour] = 4 [minutes / sheet], and the extraction pitch of group B steel slabs 2, 2,. Since the extraction pitch of [minutes / sheets], steel pieces 3, 3,... Is 10 [sheets / hour] = 6 [minutes / sheets], when the pause time associated with the roll change is 30 minutes, the presence of the target material 4x is present. The furnace time can be estimated as 4 × 4 + 3 × 4 + 6 × 2 + 30 = 70 minutes.

4). 4. Steel Production Method As a production line to which the steel production method of the present invention (hereinafter referred to as “production method”) can be applied, the form of FIG. 4 can be exemplified. The production method of the present invention only needs to include at least a heating process using a continuous heating furnace and a rolling process capable of rolling the steel slab extracted from the continuous heating furnace. Furthermore, it is possible to adopt a form in which a refining process, a heat treatment process, and the like are provided.

  As described above, according to the operation method of the continuous heating furnace of the present invention, the steel pieces in the continuous heating furnace are grouped, and the extraction pitch of the outermost group takes into account the rolling pitch in the current rolling process. While determined. Therefore, it is possible to increase the accuracy of the in-furnace time prediction of the steel slab, and as a result, the quality of the product steel can be improved. And the manufacturing method of this invention includes the operating method of the said continuous heating furnace. Therefore, the manufacturing method of steel materials which can improve the quality of product steel materials by setting it as this structure can be provided.

It is a flowchart of the extraction pitch prediction method of a continuous heating furnace. It is a conceptual diagram of the group division | segmentation method. It is a conceptual diagram of the group division | segmentation method when all the steel pieces of the outermost side group are not extracted within the regulation time T. FIG. 3A schematically shows a state before group re-division, and FIG. 3B schematically shows a state after group re-division. It is the schematic which shows the example of a form of the continuous heating furnace concerning this invention. It is a schematic diagram of an automatic furnace operation model. It is a conceptual diagram of in-furnace time prediction.

Explanation of symbols

1, 2, 3, 4 Billet 10 Heat treatment furnace 15 Detection means 20 Control device 21 CPU (first selection means, rolling pitch prediction means, heating pitch prediction means, extraction pitch prediction means, calculation means, first comparison means , Time T defining means, second sorting means)
90 Rolling process 100 Continuous heating furnace

Claims (7)

An extraction pitch prediction method for a continuous heating furnace for predicting a pitch for extracting a steel slab rolled in a rolling process from the continuous heating furnace,
Based on the material information of the steel slab charged into the continuous heating furnace, the steel slab in the continuous heating furnace is divided into the outermost group A and the group B other than the group A. A first sorting step;
Rolling pitch prediction process for predicting rolling pitch P1 at the time of maximum rolling capacity of the rolling process based on past operation results;
Based on the material information of the steel slab, a heating pitch prediction step of calculating a heating pitch P2 when the heating capacity of the continuous heating furnace is maximum;
An extraction pitch prediction step of predicting a pause time in the rolling process and calculating an extraction pitch P3 for extracting the steel slab by the pause time;
Wherein P1, P2, and compares the P3, a first comparison step of selecting a minimum pitch Px,
Compared current and the rolling pitch P4 and the P3 in the rolling step includes a second comparing step of selecting a minimum pitch Py, and,
The Py is the extraction pitch of the group A steel pieces,
The extraction pitch prediction method for a continuous heating furnace, wherein the Px is an extraction pitch of the steel pieces of the group B.
Furthermore, a time T defining step for defining a time T for correcting a prediction error of the time when the steel pieces of group A exist in the continuous heating furnace,
A second sorting step of dividing the steel pieces of group A into a group A1 extracted within the time T and a group A2 other than the group A1, and
The Py is the extraction pitch of the steel pieces of the group A1,
The extraction pitch prediction method for a continuous heating furnace according to claim 1, wherein the Px is an extraction pitch of the steel pieces of the group A2. A continuous heating furnace for heating a steel piece to be rolled in a rolling process,
A first sorting means capable of sorting a steel piece into a group A located on the outermost side and a group B other than the group A based on the material information of the steel piece to be charged;
A rolling pitch predicting means capable of predicting a rolling pitch P1 at the time of maximum rolling capacity in the rolling process based on past operation results;
A heating pitch predicting means capable of calculating a heating pitch P2 at the time of maximum heating capacity based on the material information of the billet;
An extraction pitch prediction means capable of predicting a downtime in the rolling process and calculating an extraction pitch P3 for extracting the steel slab by the downtime;
A calculation means capable of calculating a rolling pitch P4 from a current rolling speed in the rolling step;
A first comparing means capable of comparing the values of P1, P2, P3, and P4 to determine a magnitude relationship;
A continuous heating furnace comprising: Furthermore, a time T defining means capable of defining a time T for correcting a prediction error of the time when the steel pieces of group A exist in the continuous heating furnace,
A second sorting means capable of sorting the steel bills of the group A into a group A1 extracted within the time T and a group A2 other than the group A1 is provided. Item 4. The continuous heating furnace according to Item 3. A method for operating a continuous heating furnace for heating a steel slab to be rolled in a rolling process,
Based on the material information of the steel slab charged into the continuous heating furnace, the steel slab in the continuous heating furnace is divided into the outermost group A and the group B other than the group A. A first sorting step;
Rolling pitch prediction process for predicting rolling pitch P1 at the time of maximum rolling capacity of the rolling process based on past operation results;
Based on the material information of the steel slab, a heating pitch prediction step of calculating a heating pitch P2 when the heating capacity of the continuous heating furnace is maximum;
An extraction pitch prediction step of predicting a pause time in the rolling process and calculating an extraction pitch P3 for extracting the steel slab by the pause time;
Wherein P1, P2, and compares the P3, a first comparison step of selecting a minimum pitch Px,
Compared current and the rolling pitch P4 and the P3 in the rolling step includes a second comparing step of selecting a minimum pitch Py, and,
Extracting the steel bill of group A with the Py;
A method for operating a continuous heating furnace, wherein the steel pieces of the group B are extracted and operated with the Px.
Furthermore, a time T defining step for defining a time T for correcting a prediction error of the time when the steel pieces of group A exist in the continuous heating furnace,
A second sorting step of dividing the steel pieces of group A into a group A1 extracted within the time T and a group A2 other than the group A1, and
The steel pieces of group A1 are extracted with the Py,
The operation method of the continuous heating furnace according to claim 5, wherein the steel pieces of the group A2 are extracted and operated with the Px. A method for producing a steel material, comprising the method for operating a continuous heating furnace according to claim 5 or 6.

Images