JP2007058675A - Slab design method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow slab design for reducing redundant parts in a slab for increasing slab individual weight, and to realize manufacturing cost reduction through productivity improvement. <P>SOLUTION: A method for designing slabs, corresponding to orders for a plurality of steel products for which a manufacturing specifications constituted of a plurality of condition items is set arbitrarily for each order, includes (1) a step for sequentially assigning standard slabs matching, in terms of the manufacturing specification to the order for a prescribed period and producing a set of orders, for which redundant parts are caused in the standard slabs; (2) a step for producing a combination packing, for one slab, a plurality of orders bearing the common manufacturing specification, regarding manufacturing specifications including a prescribed condition item being moderated, in a set of orders each causing redundant parts; and (3) a step for determining the propriety of moderation of the manufacturing specifications for each order, in each produced combination, and for making the step (2) to produce another combination, for the order for the combination, when the order has been placed for which the moderation of the manufacturing specification has been determined as disapproval according to the determination. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a slab design method capable of reducing surplus portions in a slab and increasing a slab unit weight when designing a slab as a material for manufacturing a thin plate product such as a coil in the steel industry.

  Steel makers have traditionally produced thin-plate products such as coils using a build-to-order method. In this build-to-order manufacturing system, when an order is received from a customer, the slab design according to the order and production of the product are instructed to the production line, and the slab is cast and processed on the production line according to this instruction. In the final process, a predetermined amount of a thin plate product of a variety and mass that can satisfy the customer's order is collected and delivered to the customer by a specified delivery date.

  In this build-to-order manufacturing method, from the viewpoint of order digestion yield, the surplus part in the slab is reduced as much as possible, and the slab unit weight is made as large as possible in the manufacturing process to reduce the manufacturing cost. It is desirable to design the slabs so that they are combined into one slab.

  Several literatures disclose slab design methods for realizing this. For example, in Patent Document 1 (Japanese Patent Laid-Open No. 10-214103), a plurality of reference slab unit weights are prepared in advance for each order, and an optimum reference slab unit weight is selected from the allocation results of each reference slab unit weight and the order quantity. It is a slab design method that adopts. However, the types of standard slabs that can be prepared are naturally limited, and in addition, it is necessary to have separate standard slabs according to manufacturing specifications, that is, indicators such as components and characteristics. It is difficult to respond sufficiently.

  In addition, as a conventional general technique, a multi-order packing design in one slab has been studied. This is a slab design method characterized by retrieving a combination of orders applied to a reference slab (a surplus part of a slab) for a fractional order and a reference slab. However, in this method, the slab manufacturing specifications are fixed in advance and the combination of orders and slabs is searched. Therefore, combinations of orders and slabs can be found only within the range where these conditions are met. Today's diversification is not effective.

JP-A-10-214103

  As a result of examining the slab design based on the above recognition, the present invention has found that the filling degree of slab filling can be improved by considering the setting of each condition in the manufacturing specification.

The present invention has the following configuration.
That is, a method for designing a slab corresponding to an order for a plurality of steel products, in which manufacturing specifications including a plurality of condition items are arbitrarily set for each order,
(1) A step of sequentially assigning reference slabs conforming to manufacturing specifications to orders for a predetermined period, and creating a set of orders in which a surplus part is generated in the reference slabs;
(2) creating a combination in which a plurality of orders with common manufacturing specifications are packed in one slab with manufacturing specifications with relaxed predetermined condition items in a set of orders in which the surplus part occurs;
(3) In each of the created combinations, it is determined whether or not the manufacturing specifications can be relaxed for each order. If there is an order that the manufacturing specifications cannot be relaxed by the determination, A step of creating another combination by the step (2) again;
(4) assigning a slab of a common manufacturing specification in which a predetermined condition item is relaxed for a combination determined to be relaxable in manufacturing specification by the determination;
(5) For an order for which a combination determined to be relaxable in the manufacturing specification in the step (3) is not found, assigning a slab conforming to the manufacturing specification of the order;
A slab design method characterized by having

  The reference slab is, for example, the maximum mass allowed in the passing process. In addition, when assigning a reference slab that meets the manufacturing specifications in step (1) above, for orders that exceed the maximum mass allowed in the passing process, the reference slab is assigned repeatedly, and a surplus portion is generated in the reference slab. The remaining part may be included in a set of orders in which the surplus part is generated.

  Further, when the manufacturing specifications are relaxed in the step (2), it may be allowed to change a predetermined condition item to a higher condition or a changeable condition.

  In addition, regarding the order determined to be unrelaxable in the manufacturing specification in the step (3), another combination was created a predetermined number of times when another combination was created in the step (2). With respect to the order, a slab suitable for the manufacturing specification of the order may be assigned in the step (5) without creating another combination in the step (2) again.

  In addition, when assigning a slab with a common manufacturing specification with the specified condition items relaxed in step (4) above, the unit weight of the slab is packed into the slab as long as it is within the allowable range in the passing process. You may make it substantially correspond to the sum total of each order concerning a combination.

  In addition, when assigning a slab that conforms to the manufacturing specifications of an order for which a combination was not found in step (5), the combination was not found as long as the unit weight of the slab was within the allowable range of the passing process. You may make it substantially correspond to an order.

  According to the present invention, when designing a slab corresponding to a plurality of fractional orders with different manufacturing specifications such as slab quality characteristic values, the restrictions on the manufacturing specifications are relaxed under a certain condition, and a combination of the order and the slab is searched. By setting common manufacturing specifications that satisfy slab quality characteristic values, etc., it is possible to design a slab that contains multiple orders in one slab. As a result, it is possible to design a slab that increases the unit weight of the slab without increasing the surplus portion in the slab, and it is possible to reduce the manufacturing cost by improving the productivity of the manufacturing process.

Hereinafter, embodiments of the present invention will be described in detail.
The present invention is a slab design method whose primary purpose is to increase the unit weight of a slab as much as possible, and optimizes the packing of orders as much as possible into a slab of a reference size. As a method, multiple fraction orders with different manufacturing specifications such as quality characteristic values, etc., are searched for combinations with manufacturing specifications with the specified condition items relaxed among the manufacturing specifications, and the specifications are relaxed for the obtained combinations. Is to assign common manufacturing specifications. According to the above method, it is possible to design a slab in which multiple fraction orders with different manufacturing specifications are packed in one slab, so that it is possible to design a slab that increases the slab unit weight without increasing the surplus part in the slab. Become.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a flowchart for explaining a slab design method according to an embodiment of the present invention. “S” in the figure means a step. For reference, FIG. 2 shows a flowchart of a slab design process for packing multiple orders, which is a conventional general technique. The processing described below is actually executed on a computer for production management, and information necessary for processing (order information, equipment constraint range information, processing programs, etc.) is stored on a disk or memory in the computer. Pre-stored.

  First, orders for a wide variety of steel products are ordered from steel manufacturers. In this case, manufacturing specifications corresponding to steel products are arbitrarily set for each order. Manufacturing specifications corresponding to steel products consist of multiple condition items such as quantity (mass), composition, grade, dimensions, continuous casting machine to be used, and the like. The manufacturing specifications composed of a plurality of condition items are arbitrarily set for each order, and the manufacturing specifications of each order are not the same, and are different for each order. Accordingly, in the present invention, the processing shown in the following steps S1 to S5 is performed in response to such orders for a plurality of steel products, and slab design is performed in consideration of each order.

(1) Step S1 of sequentially assigning reference slabs that meet the manufacturing specifications to orders for a predetermined period and creating a set of orders in which surplus portions are generated in the reference slabs
First, reference slabs that conform to manufacturing specifications are sequentially assigned to a plurality of orders for a wide variety of steel products ordered in a predetermined period. In this case, the predetermined period is a period such as one week or one month, for example, and a plurality of orders ordered one after the other are separated into unit periods such as one week or one month. The present invention is applied to each set unit of a plurality of orders placed in (1). In setting the predetermined period, instead of a time period such as one week or one month, for example, a predetermined period is set when a predetermined number of orders are placed, or the total weight of each order is determined. It is also possible to divide the period according to the number of orders and other parameters, such as setting a predetermined period when a fixed amount is reached.

  When assigning a reference slab conforming to the manufacturing specification to each order made in a predetermined period in this way, for example, the reference slab having the maximum mass allowed in the passing process is applied. Here, the passage process refers to the various production processes, delivery processes, etc. through which the slab or steel plate passes from the start of slab production that meets the production specifications of each order to delivery to the customer as hot-rolled steel sheet or cold-rolled steel sheet. The slab with the maximum mass allowed within the range that considers the facility restrictions that pass through the manufacturing process, delivery process, etc., and the allowable unit weight range at the time of customer delivery, is taken as the reference slab.

  In this step S1, for example, when the quantity (mass) in the production specification determined for an order is X, and the maximum mass allowed in the passing process for a reference slab that meets the production specification for the order is Y Specifically, first, by comparing the quantity X and the maximum mass Y, whether or not a reference slab conforming to the manufacturing specifications of the order can be assigned to the order, that is, for the order It is determined whether or not a surplus portion is generated when a reference slab having a maximum mass allowed in the passing process is applied.

  When the quantity X = the maximum mass Y, no surplus portion is generated, and therefore, a reference slab conforming to the manufacturing specification of the order is assigned to the order. This completes the slab design for that order.

  On the other hand, if quantity X <maximum mass Y, if a reference slab that matches the manufacturing specifications of the order is assigned to the order as it is, an excess part (Y-X) exceeding the order is generated in the reference slab. End up. Therefore, a reference slab is not assigned to an order in which the quantity X <maximum mass Y and the surplus part is generated, and the order is put in the set U of orders in which the surplus part is generated.

  Thus, in this step S1, the quantity X is compared with the maximum mass Y for each order made during a predetermined period, and if the quantity X = maximum mass Y, a reference slab is assigned to that order. On the other hand, if quantity X <maximum mass Y, the order is placed in the order set U in which the surplus part occurs, thereby creating the order set U in which the surplus part occurs in the reference slab.

  When the amount X and the maximum mass Y are compared for each order in step S1, the amount X may exceed the maximum mass Y allowed in the passing process depending on the order. For orders with such an amount X> maximum mass Y, the reference slab with the maximum mass Y is repeatedly subtracted as much as possible, and each reference slab that matches the manufacturing specifications of the order is assigned one by one. . Finally, the remaining part that would cause the surplus part in the reference slab may be included in the order set U in which the surplus part occurs.

(2) Step S2 of creating a combination in which a plurality of orders having the same manufacturing specifications are packed in one slab with manufacturing specifications with relaxed predetermined condition items in the order set U in which the surplus part occurs
Next, in step S2, first, in the order set U in which the surplus part created in step S1 described above occurs, the condition items that can be relaxed in the manufacturing specifications defined for each order are relaxed. As mentioned above, manufacturing specifications have multiple condition items such as quantity (mass), composition, grade, dimensions, continuous casting machine to be used, etc. Among these condition items, for example, surface grade, Grades etc. are allowed to have superior conditions that are superior to manufacturing specifications if cost and other factors are ignored. For example, there are condition items that are allowed to be changed, such as using another continuous casting machine instead of a continuous casting machine to be used. Therefore, in the manufacturing specifications determined for each order, the condition items that can be relaxed are selected in advance.

  In this step S2, in the order set U in which the surplus part created in the above-mentioned step S1 occurs, first, it can be changed among the condition items that can be relaxed in the manufacturing specifications defined for each order. The manufacturing specification is relaxed by permitting the change of a predetermined condition item to a higher condition or allowing the change to a changeable condition. Then, after making a manufacturing specification in which predetermined condition items are relaxed for each order, a combination in which a plurality of orders having the same manufacturing specification are packed in one slab is created. It should be noted that searching for possible combinations between orders based on such relaxed manufacturing specifications is a general combination problem (slab: order = M: N), so is it possible to use commercially available package software? You can find combinations. In the conventional method shown in FIG. 2, an optimum combination is created so that only orders that completely satisfy the condition items in the manufacturing specification can be combined.

(3) In each of the created combinations, it is determined whether or not the manufacturing specifications can be relaxed for each order. If there is an order that the manufacturing specifications cannot be relaxed by the determination, the order of the combination is determined. , Step S3 for creating another combination again in Step S2.
As described above, in step S2, a combination in which a plurality of orders having the same relaxed manufacturing specifications are packed in one slab is created. However, if the change of the condition items becomes excessive, it may not be preferable. For example, if the surface grade, internal grade, etc. are significantly higher than the order, there may be cases where the cost is not met. Alternatively, depending on the combination of the changed condition items, there may be a condition setting that cannot be manufactured.

  In step S3, first, in each combination created in step S2, it is determined whether or not the manufacturing specification can be relaxed for each order. Here, whether or not relaxation is possible is determined by whether or not the change of the condition items relaxed to make a common production specification in each order included in the union created in step S2 meets a predetermined condition. to decide. As an example, in quality condition items such as surface grades and internal grades, for example, a change (relaxation) that raises the grade by one level is “possible”, and a change (relaxation) that raises two or more grades is “impossible”. Or, if the combination of the condition items after the change (relaxation) is within the predetermined combination range, “Yes” is set, otherwise “No” is set.

  If there is an order that is determined to be inevitable in manufacturing specifications during the combination by this determination, the combination is canceled. Then, for each order for which the combination has been canceled, the process returns to the above-described step S2 again to create another combination. In this way, when each order whose combination has been canceled is returned to step S2 to create another combination, if the number of orders within a predetermined period is small, each order is breached to ease manufacturing specifications. It is possible to repeatedly search for possible combinations. However, if the number of orders is large, considering the calculation function, etc., the number of times to return to step S2 and create another combination is determined in advance. It is desirable to return to step S2 within the range and create another combination. Some commercially available package software has functions such as setting the creation order of combinations so that the same combination is not repeated many times, or storing a once created combination. Some of the optimum combinations are selected by calculating an evaluation index based on the average slab unit weight or the number of slabs, and it is more preferable to use these.

(4) Step S4 for allocating a slab of a common manufacturing specification in which a predetermined condition item is relaxed for a combination determined to be relaxable in manufacturing specification by the determination.
Next, in step S4, for the combination determined to be able to relax the manufacturing specification by the determination in step S3, the combination is determined, and a common manufacturing specification slab in which predetermined condition items are relaxed is assigned. In this case, if a combination has been created in which a plurality of orders with different manufacturing specifications are packed into one slab, at least some of the orders in the combination can be changed within a range that can be relaxed. It has been made. For example, for some orders, quality condition items such as surface grades and missing grades have been changed (relaxed) to higher grades that match other orders within a specified range (for example, up to one level). Or, for each order, the combination of the condition items is changed (relaxed) within a predetermined combination range.

  In step S4, when assigning a slab having a common manufacturing specification in which predetermined condition items are relaxed, the unit weight of the slab is packed into the slab as long as it is within the allowable range in the passing process. Match the sum of each order in the combination. For example, if the quantities (mass) in the production specifications determined for the two orders for the combination packed in the slab are X1 and X2, these two are within the allowable range of the passing process. The unit weight of the slab packed with the combination of orders is X1 + X2. However, when the sum (X1 + X2) of the quantities (mass) of the two orders is not within the allowable range for the passing process, the unit weight of the slab is the minimum mass within the allowable range for the passing process.

(5) Step S5 for assigning a slab suitable for the manufacturing specification of the order for the order for which the combination determined to be relaxable in the manufacturing specification is not found in Step S3
On the other hand, in step S5, a slab according to the order conforming to the manufacturing specification of the order is assigned to the order for which the combination determined that the manufacturing specification can be relaxed in step S3 is not found until the end. As described above, for each order included in the combination determined to be unrelaxable in the manufacturing specification in step S3, the process returns to step S2 again to create another combination, but within a predetermined period. If there are many orders, the processing time will be long if all combinations of orders are considered. Therefore, in consideration of the calculation function, etc., for each order included in the combination determined to be unrelaxable in the manufacturing specification in step S3, the number of times of returning to step S2 and creating another combination is determined in advance. , Regarding an order that has already been created a predetermined number of times for creating another combination, it is determined that the combination that is determined to be able to relax the manufacturing specification is not found, and another combination according to step S2 is again performed. In step S5, a slab that conforms to the manufacturing specifications of the order is assigned.

  In this step S5, when assigning a slab conforming to the manufacturing specification of the order in which the combination determined to be relaxable as described above is not found until the end, the unit weight of the slab is allowed in the passing process. Match orders for which no combination was found as long as they are within the scope For example, if the quantity (mass) in the production specification for an order for which this combination was not found is X3, the slab assigned to the order for which this combination was not found, as long as it is within the allowable range for the passing process. The unit weight of X is X3. However, if the order quantity (mass) X3 for which this combination was not found is not within the allowable range for the passing process, the unit weight of the slab shall be the minimum allowable mass for the passing process. .

  In this way, the slab design for the order within a predetermined period is completed by appropriately assigning the slab of the manufacturing specification corresponding to each case. Then, slabs are sequentially designed for orders within the next predetermined period.

  As mentioned above, although an example of embodiment of this invention was demonstrated, this invention is not limited to the form shown here. For example, in step S1, the example in which the maximum mass allowed in the passing process is used as the reference slab initially assigned to each order placed in a predetermined period has been described. May not necessarily have the maximum mass. The unit weight of the reference slab is preferably as large as possible, but is not particularly limited as long as it is within a range allowed in the passing process.

  The present invention is implemented using a computer as described above. FIG. 3 shows a functional block diagram according to the embodiment of the present invention. Specifically, the information regarding the order, the information regarding the reference slab, and the information regarding the set U are stored in the storage means of the computer and read out as necessary. Information relating to orders and information relating to reference slabs stored in the storage means are read out by the CPU of the computer and used for each processing from step S1 to step S5. In other words, the CPU operates as a function for comparing the quantity X and the maximum weight Y, a function for relaxing the specification, and a function assigned to the reference slab based on them, and finally the slab design information is obtained. Output.

  Next, examples of the present invention will be described. When the slab design by the method of the present invention shown in FIG. 1 is performed for the order of the seven hot-rolled steel plates (Nos. 1 to 7) shown in Table 1, and the multi-order packing by the conventional general method shown in FIG. We compared the results of the slab design when the included slab design was performed. Here, the condition items set in the manufacturing specifications for each order are the order quantity (t), component code, surface grade, internal grade, hot coil dimensions (thickness (mm), width (mm)), continuous There are casting machine availability categories, of which the surface grade, internal grade, hot coil thickness (mm), and continuous casting machine availability category are relaxable condition items (*). Among these, for the surface grade and internal grade, combinations that can be set according to the component code are defined as shown in Table 2. Here, the smaller the grade value, the better.

  Further, the coil single weight limit determined by the width of the hot coil is separately defined, and is shown in Table 1, Table 3, and Table 4. In a continuous casting machine in a recent integrated steelworks, the width can be set to a predetermined value for each slab, and the length can be adjusted to some extent at the cutting position. The present embodiment is also examined based on this premise, but a slab to which an order less than the minimum unit weight is given is designed with the minimum unit weight, and the difference from the order quantity is the surplus quantity.

  Tables 3 and 4 show the results of slab design according to the method of the present invention and the conventional method, respectively. Here, the average surplus rate is the average surplus divided by the average slab weight. In Table 3, slab no. For 2, 3 and 4, the slab quality characteristic value, continuous casting machine, and hot coil thickness are set in accordance with the standardized specifications. Of these, Slab No. It was judged that the hot coil thickness of 4 could be combined because it could be split and hot rolled in the hot rolling process.

  As is clear from the comparison between Table 3 and Table 4, it can be confirmed that the slab design method according to the present invention realizes a slab design in which the slab unit weight is increased while suppressing the surplus in the slab.

  The present invention can be used, for example, in designing a slab that is a material for manufacturing a thin plate product.

It is a flowchart for demonstrating the slab design method concerning embodiment of this invention. It is a flowchart of the slab design process of multiple orders packing which is a conventional general technique. It is a functional block diagram concerning an embodiment of the invention.

Claims (7)

A method for designing a slab corresponding to an order for a plurality of steel products, in which manufacturing specifications including a plurality of condition items are arbitrarily set for each order,
(1) A step of sequentially assigning reference slabs conforming to manufacturing specifications to orders for a predetermined period, and creating a set of orders in which a surplus part is generated in the reference slabs;
(2) creating a combination in which a plurality of orders with common manufacturing specifications are packed in one slab with manufacturing specifications with relaxed predetermined condition items in a set of orders in which the surplus part occurs;
(3) In each of the created combinations, it is determined whether or not the manufacturing specifications can be relaxed for each order. If there is an order that the manufacturing specifications cannot be relaxed by the determination, A step of creating another combination by the step (2) again;
(4) assigning a slab of a common manufacturing specification in which a predetermined condition item is relaxed for a combination determined to be relaxable in manufacturing specification by the determination;
(5) For an order for which a combination determined to be relaxable in the manufacturing specification in the step (3) is not found, assigning a slab conforming to the manufacturing specification of the order;
A slab design method characterized by comprising:   The slab design method according to claim 1, wherein the reference slab is a maximum mass allowed in a passing process.   When assigning a reference slab that meets the manufacturing specifications in step (1) above, for orders that exceed the maximum mass allowed in the passing process, the reference slab is assigned repeatedly, and a surplus part is generated in the reference slab. The slab design method according to claim 2, wherein the remaining portion is included in a set of orders in which the surplus portion is generated.   4. The method according to claim 1, wherein when the manufacturing specification is relaxed in the step (2), the predetermined condition item is allowed to be changed to a higher condition or a changeable condition. 5. The slab design method described.   For an order that has been determined that the manufacturing specifications cannot be relaxed in the step (3), when another combination is created in the step (2) again, the order in which another combination has been created a predetermined number of times. In the step (5), a slab that conforms to the manufacturing specifications of the order is allocated without creating another combination in the step (2) again. The slab design method according to any one of the above.   When assigning a slab with a common manufacturing specification in which the predetermined condition items have been relaxed in the step (4), the unit weight of the slab is the combination packed in the slab as long as it is within the allowable range of the passing process. The slab design method according to any one of claims 1 to 5, wherein the slab design method substantially matches the sum of the orders.   When assigning a slab that meets the manufacturing specifications of an order for which a combination was not found in step (5) above, the unit weight of the slab will be assigned to an order for which no combination was found, as long as it is within the allowable range for the passing process. The slab design method according to claim 1, wherein the slab design methods are substantially matched.

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