JP2008073724A - Slab design method and slab design apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slab design method and a slab design apparatus which attain enhancement in the yield even of small-lot production of a wide variety of products such as thick steel plates by reducing the inventory of the products and generation of scraps. <P>SOLUTION: The slab design method and the slab design apparatus for reserving order to slabs based on order information and slab information in a manufacturing process of thick steel plates is equipped with respectively: a judgment step and a judgment means for judging whether or not the size for obtaining a slab from a remaining part of the slab after reserving the order to a specified slab can be manufactured; and a slab order reserving step and a slab order reserving means for reserving the order for manufacturing the slab of size for obtaining the slab from the remaining part of the slab after reserving the order if it is judged by the judgment step and the judgment means that the size for obtaining the slab can be manufactured. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a slab design method and a slab design apparatus for assigning orders to slabs in the manufacturing process of thick steel plates.

  Thick steel plate is a slab manufactured in a continuous casting process or ingot-splitting in a steelmaking process, after hot rolling so as to have a predetermined plate thickness according to the customer's order in the slab unit, Manufactured by cutting according to product dimensions. In general, the order form and characteristics of these thick steel plates are often small lots and various types, and the production is almost always the order production method.

  In the case of producing such a small lot and a variety of products, in order to produce efficiently and economically, it is important to have a production plan that consolidates the production lots in each production process unit. In the aggregation to the production lot, there is an operation of combining a plurality of order dimensions into a rolling unit, that is, a slab unit. This is done by first grouping from the characteristics of the order, and combining the orders so that the loss generated by combining different order sizes within the range satisfying the equipment constraints within the same group is minimized. To decide.

  Many methods for combining such orders have been proposed. For example, in Patent Document 1, when manufacturing a steel sheet product in response to an order from a customer, optimal allocation to the ordered product material is realized in a short time, and surplus inventory and yield are managed in an optimal state. An allocation method that can be done is described.

  Patent Document 2 describes a method of determining an optimal combination of orders using a genetic algorithm when assigning one or more orders to each of a plurality of slabs.

Further, in Patent Document 3, when one or more orders are allocated to a plurality of pieces of steel and an order combination is determined, all the conceivable items are considered under the constraints for eliminating equipment constraints and redundant combinations. After enumerating the combinations of the above by the branch and bound method, by selecting the billet that maximizes the target evaluation function under the restriction of the number of orders using the 0-1 programming method from among the enumerated combinations A method for determining the optimal order combination is described.
Japanese Patent Laid-Open No. 6-149850 Japanese Patent Laid-Open No. 7-96311 JP 2004-276034 A

  However, all of the methods described in Patent Documents 1 to 3 pursue the optimality of order combination in slab allocation when the degree of freedom of order combination and slab allocation is large. Therefore, the above method is considered to be effective when the degree of freedom of order combination is large, but the degree of freedom of order combination is extremely low particularly when producing small lots and various types of products such as thick steel plates. In some cases, the yield cannot be improved significantly.

  That is, in the case of a small lot material with few orders to be combined, even if a slab having the best yield among many slab groups is selected and the order is allocated, a surplus material portion often occurs in the slab.

  FIG. 6 schematically shows a rolling state when the order 1a is applied to the slab 1 in the conventional method. Usually, when the surplus material portion 1b as shown in FIG. 6 is generated, the slab is often cut in accordance with the dimensions of the order at the stage of placing the order 1a on the slab 1. However, when the slab is cut, if the remaining dimensions are less than the minimum slab dimensions determined by equipment constraints such as handling, heating, and rolling, scrap is generated. For this reason, in the case of scrap, rolling is performed as it is, and the remaining material portion 1b is collected as a product inventory after rolling, or is subjected to scrap processing, which often results in a low yield.

  Therefore, the present invention provides a slab design method and a slab design apparatus capable of reducing product inventory or scrap generation and improving yield even when producing a small lot and a variety of products such as thick steel plates. The purpose is to provide.

In order to solve the above problems, the present invention has the following features.
[1] A slab design method for assigning orders to slabs based on order information and slab information in the manufacturing process of thick steel plates,
A determination step for determining whether or not a dimension that can be collected as a slab can be manufactured for the surplus material portion of the slab after the order is assigned to the specific slab, and
When it is determined in the determination step that a dimension that can be collected as a slab is manufacturable, a slab order allocation that allocates an order for manufacturing a slab of a size that can be sampled to the remaining material portion of the slab after the order allocation. And a slab design method.
[2] In the above [1], the determination step determines the slab size within a range not less than the minimum slab size and not more than the maximum slab size that satisfies the constraint condition of the equipment for rolling the surplus material portion. Design method.
[3] A slab design device for assigning orders to slabs based on order information and slab information in the manufacturing process of thick steel plates,
A determination unit that determines whether or not a dimension that can be collected as a slab can be manufactured for the remaining material portion of the slab after the order is assigned to the specific slab,
When it is determined by the determination means that a dimension that can be collected as a slab is manufacturable, a slab order allocation that allocates an order for manufacturing a slab of a size that can be sampled to the remaining material portion of the slab after the order allocation. Means for designing a slab.

  According to the present invention, a slab design method and a slab design apparatus capable of reducing product inventory or scrap generation and improving yield even when producing small lots and various products such as thick steel plates. Is provided.

  Hereinafter, an example of the best mode for carrying out the present invention will be described.

  The present invention relates to a slab design method and a slab design device for assigning orders to slabs based on order information and slab information in the manufacturing process of thick steel plates, each of which is a surplus material of the slab after the order is assigned to a specific slab. A determination step and a determination means for determining whether or not a dimension that can be collected as a slab can be manufactured, and a dimension that can be sampled as a slab is determined to be manufactureable by the determination step and the determination means Includes a slab order assigning step and a slab order assigning means for assigning an order for producing a slab having a size that can be collected with respect to the remaining material portion of the slab after the order is assigned. Here, as the slab design device, a computer or the like can be used, and the surplus material portion of the slab after assigning the order for the specific slab based on the order information and the slab information to the computer or the like, Further, determination means for determining whether or not a dimension that can be collected as a slab can be manufactured, and when the determination means determines that a dimension that can be collected as a slab can be manufactured, the remaining material of the slab after the order is allocated The apparatus can be configured by reading a program for functioning as a slab order assigning means for assigning an order for manufacturing a slab of a size that can be collected to a part.

  Hereinafter, the details of the processing in each of the above steps (the same applies to each means) will be described with reference to FIGS. Here, FIG. 1 is a diagram showing an example of a processing flow of the slab design method according to the present invention. Moreover, FIG. 2 is a figure which shows an example of the functional block structure of the slab design apparatus based on this invention.

[Determination Step (S1)]
As shown in FIG. 1, in this determination step (S1), first, order information and slab information are read in S11. More specifically, information about orders that should be manufactured is read from the order information database 101, and information on slabs to which these orders can be assigned is read from the slab information database 102. Here, the order information database 101 stores data relating to orders such as product standards, dimensions, specifications, and delivery dates. In the slab information database 102, for example, slab data such as slab size, steel type, slab production time, and the like are stored. Note that the data read in S11 is stored in a database or the like.

  Next, in S12, based on the order information and the slab information read in S11, the order for which the production should be started is allocated to the slab. As the allocation method, for example, for each order, a slab having the best yield is selected from the slab groups that can be allocated the order read in S11, and the order is allocated to the slab. it can. In this case, when the yield is improved by combining a plurality of orders for one slab, a plurality of orders may be allocated for one slab.

  Note that S11 and S12 are performed by the order information and slab information reading unit 11 and the order slab allocation processing unit 12 shown in FIG.

  Next, in S13, it is determined whether or not a predetermined order can be allocated or a slab larger than the minimum slab size can be collected by dividing the surplus material portion of the slab to which the order has been allocated in S12. I do. In addition, the said surplus material part is parts other than a slab area | region required in order to extract | collect the assigned order within a slab. Here, the size of the surplus material portion is equal to or larger than the slab size that can be allocated to an existing order, or larger than the minimum slab size that can be processed, which is determined by slab handling constraints, heating, rolling, and other equipment constraints. Judgment is made by whether or not there is.

  And in this S13, when it is determined that it is possible to allocate a predetermined order or to collect a slab larger than the minimum slab size by dividing the slab, the remaining material portion is divided as possible (Yes). Make a possible decision. This division possibility determination is sent to a production management system that manages production instructions and production results at each factory and site, and a division instruction for the slab is created and division processing is performed.

  Further, in this S13, if it is determined that even if the slab is divided, it is not possible to allocate a predetermined order or to collect a slab larger than the minimum slab size, it is determined that the remaining material portion cannot be divided (No). The process proceeds to S14 below.

  Note that the above S13 is performed by the surplus material part division possibility determination unit 13 shown in FIG.

  In the present invention, the process of S13 is not an essential process, and the process may proceed directly to S14 without determining whether or not division is possible, and even in that case, the effects of the present invention can be achieved. By performing S13 described above, the slab that can be divided is divided, and the following steps are omitted, so that the entire process can be simplified.

  Next, in S14, it is determined whether or not the remaining material portion of the slab that has been determined to be non-dividable (No) in S13 can be manufactured with dimensions that can be collected as a slab. .

  FIG. 3 shows an example of the processing flow in S14.

In S14, first, in S141, the maximum thickness difference is calculated. The maximum amount of different thicknesses refers to the maximum permissible value of the difference in sheet thickness when performing rolling while changing the finished rolling thickness in accordance with the order within one slab. Here, the technique of different thickness rolling used when manufacturing a differential thickness steel plate, a taper plate, etc. is applied. FIG. 4 schematically shows how rolling is performed when different thickness rolling is performed. Here, the amount of different thickness refers to the difference in plate thickness between t ₁ and t ₂ in the steel plate after rolling the slab 1 in FIG. The maximum thickness difference is a value determined by the steel type, rolling dimensions (rolling thickness, rolling width, etc.), equipment constraint conditions of the rolling equipment, etc. If the rolling dimensions based on the order are given for each rolling equipment, It is a value that can be calculated uniquely.

  Next, in S142, it is determined whether or not different thickness rolling is possible. This determination can be made based on whether the maximum thickness difference calculated in S141 satisfies the following expression (1).

Slab minimum thickness-rolling thickness≤maximum thickness difference (1)
Here, the minimum slab thickness is the minimum thickness of the slab defined by the minimum slab size that can be processed, which is determined by the handling constraints of the slab and the equipment constraints such as heating and rolling. The rolled thickness is a finished rolled thickness based on the assigned order.

  Here, when the above formula (1) is satisfied (Yes), it is determined that the different thickness rolling is possible, and the process proceeds to S143 below. When the above formula (1) is not satisfied (No), the different thickness rolling is performed. The processing is terminated as being impossible.

  Next, in S143, for the slab determined to be capable of different thickness rolling in S142, whether or not a dimension that can be collected as a slab from the surplus part of the slab can be manufactured, for example, from the surplus part It is determined whether or not a slab larger than the minimum slab size can be manufactured. Here, for the surplus material portion, for example, the slab length is calculated when the thickness is the slab minimum thickness and the width is the rolling width of the assigned order, and this is defined as the minimum slab dimension. If it is longer than the length (minimum slab length), it is determined that a dimension that can be collected as a slab can be manufactured. If the calculated slab length is less than the minimum slab length, it is determined that manufacturing is impossible.

  When it is determined in S143 that a dimension that can be collected as a slab can be manufactured (Yes), the process proceeds to the next step, a slab order allocation step (S2), and a dimension that can be collected as a slab is determined to be unmanufacturable (No). If so, the process ends.

  Note that S14 is performed by the slab collection availability determination unit 14 shown in FIG.

[Slab order allocation step (S2)]
As shown in FIG. 1, in this slab order assigning step (S2), first, in S21, the slab size to be collected from the surplus material portion of the slab is determined. Here, as the slab size to be collected, as calculated in S143, when the thickness is the minimum thickness of the slab and the width is the rolling width of the assigned order, the slab size of the calculated slab length is If it is below the maximum slab size within the range of handling constraints and equipment constraints such as heating and rolling, a slab of this size can be made the slab size to be collected.

  Here, when the calculated slab length exceeds the maximum slab length that can be processed, which is defined by handling constraints and equipment constraints such as heating and rolling, the slab thickness is within the range of the maximum slab length or less. Adjust the thickness and slab width to determine the slab size to be collected. Even if the calculated slab length is equal to or less than the maximum slab length, the slab size to be collected may be determined by adjusting the slab thickness and slab width.

  The slab thickness can be adjusted in a range of not less than the minimum slab thickness and not more than the maximum different thickness. In addition, the slab width can be adjusted in a range of not less than the minimum slab width and not more than the maximum slab width defined by handling constraints, equipment constraints such as heating and rolling, if different width rolling is possible. Furthermore, the slab length can also be adjusted in the range of the minimum slab length or more and the maximum slab length defined by handling constraints, heating, rolling and other equipment constraints.

  Here, when adjusting the size of the slab to be collected, it is preferable to adjust the slab thickness as much as possible. This is because the thicker the slab, the greater the degree of freedom in assigning orders to the slab.

  In addition, said S21 is performed by the slab dimension determination part 21 shown in FIG.

  Next, in S22, an order is allocated to the surplus material part. Here, a virtual order for manufacturing the slab having the dimensions determined in S21 may be created, and the virtual order may be allocated to the remaining material portion of the slab.

  The order to be allocated is not limited to the virtual order, and an actual order newly received after the order information read in S11 described above may be allocated. In this case, in this S22, the order information database 101 is accessed, a new order is searched, and if there is a corresponding order, allocation is performed.

  The S22 is performed by the order assigning unit 22 shown in FIG.

  Orders for manufacturing slabs and orders for manufacturing slabs are sent to production management systems that manage production orders and production results at each factory and site, and rolling and cutting instructions for the slabs are created and rolled. And cutting is performed. The surplus material portion of the slab to which the virtual order is allocated is rolled and cut to the slab size determined in S21, and then enters a status of waiting for the order allocation.

  As mentioned above, although an example of an embodiment of the present invention was explained, the present invention may be applied to all slabs to which orders are allocated, and when a specific steel type, plate thickness and order are allocated. The present invention may be applied only to a slab that does not satisfy a predetermined yield.

  As described above, according to the present invention, the remaining material portion of the slab, which has conventionally been a product inventory or scrap, can be reused as a slab. As a result, even when producing a small lot and a variety of products such as thick steel plates, it is possible to reduce the occurrence of product inventory or scrap and improve the yield.

  FIG. 5 shows a slab when the slab design method according to the present invention is applied (example of the present invention) and when the order is allocated by the conventional method (comparative example) considering only the possibility of division. The result of the total yield is shown.

Here, the overall yield of the slab was calculated by the following equation (2).
(Product mass (t) / good slab mass per charge (molten steel) (t)) x 100 (%) (2)
As shown in FIG. 5, the overall yield of the slab, which was about 60% in the comparative example, was greatly improved to about 70% in the example of the present invention, and the effect of the present invention was confirmed.

It is a figure which shows an example of the processing flow of the slab design method which concerns on this invention. It is a figure which shows an example of the functional block structure of the slab design apparatus which concerns on this invention. It is a figure which shows an example of the processing flow in S14 which concerns on this invention. It is a figure which shows typically the mode of rolling in the case of performing different thickness rolling which concerns on the example of this invention. It is a figure which shows the result of the comprehensive yield of the slab which concerns on the example of this invention, and the comprehensive yield of the slab in a comparative example. It is a figure which shows typically the mode of rolling at the time of assigning order to the slab in a conventional method.

Explanation of symbols

  1 Slab

Claims (3)

A method for designing a slab in which an order is assigned to a slab based on order information and slab information in the manufacturing process of a thick steel plate,
A determination step for determining whether or not a dimension that can be collected as a slab can be manufactured for the surplus material portion of the slab after the order is assigned to the specific slab, and
When it is determined in the determination step that a dimension that can be collected as a slab is manufacturable, a slab order allocation that allocates an order for manufacturing a slab of a size that can be sampled to the remaining material portion of the slab after the order allocation. And a slab design method.   2. The slab design method according to claim 1, wherein the determining step determines a slab size within a range not less than a minimum slab size and not more than a maximum slab size that satisfies a constraint condition of equipment for rolling the surplus material portion. A slab design device that assigns orders to slabs based on order information and slab information in the manufacturing process of thick steel plates,
A determination unit that determines whether or not a dimension that can be collected as a slab can be manufactured for the remaining material portion of the slab after the order is assigned to the specific slab,
When it is determined by the determining means that a dimension that can be collected as a slab is manufacturable, a slab order allocation that allocates an order for manufacturing a slab of a size that can be sampled to the remaining material portion of the slab after the order allocation. Means for designing a slab.

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