JP5862487B2 - Shearability determination method, steel plate manufacturing method, and steel plate shearing equipment - Google Patents

Description

  The present invention relates to the shearing of a steel plate such as a thick steel plate, and relates to a method for determining whether or not a conveyed steel plate can be sheared by a shearing device, and a steel sheet shearing equipment employing such a determination method.

For example, as described in Patent Document 1, the thick steel plate is sheared based on a plate thickness range set in advance according to a standard (tensile strength) to determine whether shearing is possible with a shearing device. When it is determined that shearing cannot be performed, the steel sheet is subjected to various thermal cutting processes such as off-line gas cutting.
Here, whether or not shearing is possible is determined by, for example, predicting the shear load F required to shear the target steel sheet, the thickness t of the steel sheet, and the tensile strength determined for each standard. If TS and shear rake angle θ are used to calculate by the following formula, and the obtained shear load predicted value F is smaller than the maximum equipment load resistance (limit shear load) determined from the equipment conditions of the shearing device It is determined that shearing is possible with a shearing device. The following formula is a well-known formula described in “Latest Plastic Working Manual Second Edition (Edited by Japan Society for Technology of Plasticity) p.229” and the like. The coefficient A is a fixed value determined for each shearing device.
F = A · t ² · TS / tan θ

JP 2009-66699 A

Since the processing capability of various thermal cutting processes such as gas cutting is lower than that of a shearing device and is an off-line processing, it is desirable to increase the amount of steel plate sheared by the shearing device if possible. Whether or not a certain steel plate can be sheared by a shearing device is usually determined by considering a sufficient safety factor in consideration of the strength (for example, tensile strength) and size (plate thickness and width) of the steel plate. Since an excessive safety factor setting leads to a decrease in production efficiency, a method for determining whether or not shearing is as efficient as possible is required.
The present invention has been made paying attention to the above points, and aims to more appropriately determine a steel plate that can be sheared by a shearing device.

In order to solve the above problems, the invention described in claim 1 of the present invention is a shearability determination method for determining whether or not shearing is possible with a shearing device for a steel sheet being conveyed,
For each shear candidate steel plate, temperature shear information that is a relationship between the shear temperature and the coefficient A, which is the temperature at the time of shearing of the target steel plate, is obtained in advance.
Whether or not shearing is possible is determined based on the coefficient A obtained from the actual shearing temperature of the steel plate as a shear candidate and the above-described temperature shearing information and the following equation (1).
F = A · t ² · TS / tan θ (1)
here,
F: Shear load prediction value A: Coefficient for shearing t: Plate thickness of steel plate TS: Tensile strength of steel plate θ: Shear rake angle

Next, the invention described in claim 2 is the coefficient A corresponding to the shearing temperature based on the temperature shearing information obtained in advance from the actual shearing temperature of the target steel plate. The shear load prediction value F is obtained using the obtained coefficient A, and whether or not shearing is possible is determined based on the obtained shear load prediction value F.
Next, the invention described in claim 3 is characterized in that the steel plate determined to be shearable by the shearability determination method according to claim 1 or 2 is sheared by the shearing device.

Next, the invention described in claim 4 is a shearing facility for shearing a steel plate being conveyed by a shearing device, and shearing for determining shearability by the shearability determination method according to claim 1 or 2. A determination unit is provided, and when the shear determination unit determines that shearing is possible, the steel plate is sheared.
Next, in the invention described in claim 5, in addition to the shear determination unit, the structure described in claim 4 is arranged upstream of the shearing device to increase the temperature of the steel sheet during shearing. When the steel plate can be sheared when heated based on the determination of the shear determination unit, the steel plate is heated to the temperature at which shearing is possible.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to determine more appropriately whether a steel plate can be sheared with a shearing device.

It is a figure which shows the relationship between the shear temperature which concerns on embodiment based on this invention, and the shear coefficient A '. It is a figure which shows the manufacturing line containing the shearing equipment which concerns on embodiment based on this invention. It is a figure which shows the process of a shear determination part. It is a figure which shows the manufacturing line containing the shearing equipment which concerns on other embodiment based on this invention.

Next, embodiments of the present invention will be described with reference to the drawings.
(Regarding the relationship of “coefficient A′−shear temperature” employed in the present embodiment)
First, the relationship of “coefficient A′−shear temperature” employed in the present embodiment will be described.
The shear load prediction value F of the steel sheet can be expressed by the following equation (1). The equation (1) is an equation described in, for example, “Latest Plastic Working Manual Second Edition (Edited by the Japan Society for Technology of Plasticity) p.229”.
F = A · t ² · TS / tan θ (1)
here,
A: Coefficient related to shear t: Plate thickness of steel plate TS: Tensile strength of steel plate θ: Shear rake angle

Conventionally, the coefficient A is a value determined from the specifications of the equipment configuration of the shearing device, that is, the coefficient A is preset as a fixed value for each shearing device. In addition, from this, conventionally, when the target plate thickness t is determined, it is possible to determine whether shearing is possible with the shearing device based on the above equation (1).
On the other hand, in this embodiment, the coefficient A is treated as a variable value with the shear temperature α as a parameter. The shear temperature α refers to the temperature of the surface of the steel sheet during shearing.

Next, the coefficients A and A ′ of this embodiment will be described.
The coefficient A can be expressed by the following equation (2) by modifying the above equation (1).
A = tan θ · {F / (t ² · TS)} (2)
If A ′ = F / (t ² · TS), the following equation (3) is obtained.
A ′ = tan θ · A (3)
Hereinafter, instead of the coefficient A, the coefficient A ′ is a value using the shear temperature α as a parameter. The coefficient A and the coefficient A ′ are substantially the same coefficients only in the presence or absence of multiplication of the shear rake angle θ. By setting the coefficient A ′, the influence of the shear rake angle θ was excluded.

Then, when the above equation (3) is substituted into the equation (1), the following equation (4) is obtained. That is, the predicted shear load F can be obtained by multiplying the obtained A ′ by the thickness t of the target steel sheet and the tensile strength TS.
F = A ′ · t ² · TS (4)
The coefficient A ′ is a dimensionless value for the thickness t and the tensile strength TS of the target steel sheet. Along with this non-dimensionalization, in this embodiment, the tensile strength TS is used as the value of the tensile strength TS at room temperature as in the conventional case.

In the present embodiment, the relationship between the coefficient A ′ and the shearing temperature α is obtained by experiment for each steel type of the steel plate to be set in advance. However, the tensile strength TS is the tensile strength TS at room temperature as described above.
Here, when the relationship between the coefficient A ′ and the shearing temperature α was determined for the following steel types, the relationship shown in FIG. 1 was obtained. The steel plate used when obtaining FIG. 1 is C: 0.16% by mass, Si: 0.26% by mass, Mn: 0.95% by mass, P: 0.02% by mass, S: 0.016% by mass. %, The balance is Fe and inevitable component steel types.

As can be seen from FIG. 1, A ′ in a specific temperature range of about 200 to 300 ° C. is a value as small as about 1/3 of A ′ at room temperature (room temperature to around 70 ° C.). . This indicates that the predicted shear load value F is about 1/3 of room temperature in a specific region where the temperature is around 300 ° C.
In the present embodiment, the relationship between the coefficient A ′ and the shearing temperature α as described above is obtained in advance by individual experiments or the like with respect to a steel candidate that can be sheared by a shearing device. The obtained relationship of “coefficient A′−shear temperature α” is stored in the form of a function formula or a map for each steel type. The information of “coefficient A′−shear temperature α” is also referred to as temperature shear information.

(Constitution)
Next, an example of an embodiment of equipment to which the present invention is applied is shown. In the present embodiment, the present invention is applied to a crop shear after finish rolling. There is no problem even if the shearing device to which the present invention is applied is a shearing device (shear) used in a cutting process in a side shear or other equipment.
FIG. 2 is a schematic diagram illustrating an example of the equipment configuration of the present embodiment.
That is, the heating furnace 1, the finishing mill 2, the pre-leveler 3, the hot leveler 4, the cooling bed 5, the temperature detecting device 13, the crop shear 7, the side shear 8, and the end shear 9 are arranged in order from the upstream side. The steel plate 11 after finish rolling and straightening which has been lowered to the target steel plate temperature in 5 is conveyed toward the crop shear 7. At this time, the controller 12 determines whether or not the steel plate 11 can be sheared by the crop shear 7. If it is determined that the steel plate 11 can be sheared by the crop shear 7, the controller 12 sends the steel plate 11 to the crop shear 7. The crop is cut by shearing. On the other hand, if the controller 12 determines that shearing cannot be performed by the crop shear 7, the steel plate 11 is removed from the transport line and the cutting work such as gas cutting or laser cutting is performed offline, or When the controller 12 determines that shearing cannot be performed by the crop shear 7, processing is performed using downstream equipment, such as passing through the crop shear 7 without performing processing and further shearing by the downstream end shear 9. To implement.

Next, the process of the controller 12 will be described.
The controller 12 includes a shear determination unit 12A. The processing of the shear determination unit 12A will be described with reference to FIG.
In step S10, the shear determination unit 12A acquires the steel plate temperature information detected by the temperature detection device 13.
Next, in step S20, the shear temperature α at the position of the crop shear 7 is obtained based on the steel plate temperature information and the conveyance speed. That is, the temperature drop amount from the temperature detection position to the crop shear 7 is obtained, and the shear temperature α is obtained by subtracting the temperature drop amount from the detected steel plate temperature.

Next, in step S30, using the obtained shear temperature α as a parameter, the temperature shear information of the target steel type is applied to obtain the shear coefficient A ′ corresponding to the shear temperature α.
Next, in step S40, based on the above equation (4), a predicted shear load F is obtained using the thickness t of the target steel type and the tensile strength TS at room temperature.
Here, the tensile strength TS at room temperature is a value determined in advance for each steel type. The plate thickness t may be an actual measurement value or a preset plate thickness target value.
Next, in step S50, the limit shear load Fx of the crop shear 7 set in advance is compared with the predicted shear load F obtained in step S40, and the predicted shear load F is expressed by the following equation. Is less than the limit shear load Fx, it is determined that shearing is possible (step S53). On the other hand, when the following formula is not satisfied, it is determined that shearing is impossible (step S56).
F ≤ Fx

Next, in step S60, the determination result is output. The shear determination unit 12A performs the above processing every time the next material reaches the temperature detection position.
When the controller 12 determines that shearing is possible, the controller 12 directly transports the cropping shear 7 to perform shearing. On the other hand, when the controller 12 determines that shearing is not possible, an offline cutting process is performed. Alternatively, when the controller 12 determines that shearing is not possible, the crop shear 7 may be passed through without passing through the crop shear 7 and further sheared by the downstream end shear 9.

  Here, in the said embodiment, although the case where the shearing possibility determination based on this invention was applied to the crop shear 7 was demonstrated, you may apply to the end shear 9. FIG. In addition, the above-described availability determination is performed for a plurality of shears at the same time, and when all shears are allowed to be sheared, online shearing processing is performed, shearable shears are determined, and shearable shears are determined. Processing may be performed by shearing up to the position, and the remaining cutting may be performed off-line.

(Operation other)
In the present embodiment, based on the shear temperature α, the coefficient A ′ is obtained by referring to information (temperature shear information) of “coefficient A′−shear temperature α” obtained in advance, and the obtained coefficient A ′ and the target Substituting the thickness t of the steel plate 11 to be performed and the tensile strength TS at room temperature into the equation (3), the predicted shear load F is obtained. Then, based on the obtained shear load prediction value F, whether or not shearing is possible in the target shearing device is determined.
In determining whether shearing is possible, in addition to the shear load, device restrictions from the viewpoint of the steel plate size such as the plate width and thickness should be taken into consideration. Can be determined. Therefore, hereinafter, a shear load prediction method and a shearability determination method based thereon that are features of the present invention will be described.

Conventionally, the shear load predicted value F is obtained based on the tensile strength at normal temperature. In this embodiment, for example, in the steel type of FIG. 1, when the shear temperature α is 200 ° C., A ′ is It is required to be less than half that at normal temperature.
As a result, with the coefficient A ′ at room temperature, there is a high possibility that even if the steel plate 11 is determined to be unshearable by the shearing device, it can be determined that shearing is possible. That is, in the case of conventional steel plates that are determined to be non-shearable, by applying the present invention, a steel plate that is determined to be shearable and is sheared is generated, so it is possible to reduce off-line cutting. It becomes.

In addition, the coefficient A ′ obtained by making the tensile strength TS and the plate thickness t dimensionless is set as a parameter of the shear temperature α, that is, the tensile strength TS is also temperature dependent, but in predicting the shear load. The coefficient A ′ is responsible for the temperature-dependent factor, and by adopting a normal temperature value as the tensile strength TS, the shear load predicted value F can be easily calculated.
Here, in the relationship between the shear temperature α and the coefficient A ′ shown in FIG. 2, the coefficient A ′ is reduced to about ３ of the normal temperature in a specific temperature range of about 200 to 300 ° C. This specific temperature region overlaps with the temperature of the blue heat brittle region. It is known that the temperature of the blue heat brittle region generally increases the tensile strength TS and hardness of steel compared to that at room temperature, and decreases the elongation and drawing.

  Thus, since the tensile strength TS is higher than that at normal temperature at the temperature of the blue-hot brittle region, the temperature-dependent tensile strength TS itself is assumed to be the above ( When applied to the equation (1), the predicted shear load value F is higher at the temperature in the blue-hot brittle region than at normal temperature, and deviates from the actual situation. For this reason, it is necessary to obtain the shear load predicted value F by an expression different from the expression (1). On the other hand, in the present invention, the coefficient A ′ (or coefficient A) is responsible for the temperature-dependent factor in predicting the shear load, and the normal temperature value is adopted as the tensile strength TS. ), The predicted shear load value F based on the shear temperature α can be easily obtained. In addition, compared with the normal temperature, the tensile strength TS in the temperature of a blue-hot brittle area does not usually become 2 times as high.

  As described above, in the present embodiment, when the predicted shear load F obtained based on (3) is used by adopting the relationship of “coefficient A′−shear temperature α” obtained in advance, the blue hot brittle region is used. Even if the shear temperature α is other than the temperature, the actual shear load predicted value F can be obtained easily and accurately. As a result, even if it is conventionally determined that shearing is impossible, it is possible to determine that the steel plate 11 that can actually be sheared can be sheared. The cutting process can be reduced.

And, by manufacturing a steel plate such as a thick steel plate by shearing the steel plate determined to be shearable by the above-described determination method with the shearing device, a larger number of steel plates can be obtained by various types of thermal cutting than before. Therefore, it is possible to process by shearing, which contributes to improvement in production efficiency.
Here, in the above-described embodiment, the case where the shearability is determined from the shearing temperature α when reaching the shearing device has been described. Instead of this processing, the following processing may be performed.
1) Shearability based on the shearing temperature α may be performed only on the steel plate 11 whose shear load prediction value F at normal temperature is higher than the limit shear load Fx. Since the predicted shear load value F at normal temperature can be obtained in advance, the number of steel plates 11 for determining whether shearing is possible based on the shear temperature α can be reduced.
2) Further, the upper limit value Ax of the shearable coefficient A ′ is first obtained from the limit shear load Fx of the shearing device, and the coefficient Ax is compared with the coefficient A ′ obtained from the shear temperature α to perform shearing. You may determine whether it is possible.

3) From the above upper limit coefficient Ax, based on the temperature shear information, the upper limit αx of the shear temperature α at which the target plate can be sheared is obtained, and the upper limit αx is compared with the actual shear temperature α to determine whether shearing is possible. May be determined. Conversely, a heating device for heating the steel plate 11 in advance to a temperature up to the temperature where the shear temperature α is not less than the upper limit value αx and not more than the blue brittleness region may be provided separately. In this case, for example, as shown in FIG. 4, a heating device 20 is provided on the upstream side of the crop shear 7, and the steel plate 11 is heated in response to an instruction from the controller 12. Thus, the steel plate can be sheared by the crop shear 7 after confirming that the steel plate has been heated to a shearable temperature range. For example, the controller 12 outputs information on the shearable temperature of the target steel plate 11 to the heating device 20. And after heating device 20 heats steel plate 11 more than the temperature which can be sheared based on detection information of a temperature detection device which is not illustrated, steel plate 11 is conveyed to the crop shear 7 side.
Here, in the above description, the coefficient A ′ is used. However, the coefficient A (= A ′ / tan θ) itself may be used instead of the coefficient A ′.

7 Crop shear (shear device)
DESCRIPTION OF SYMBOLS 11 Steel plate 12 Controller 12A Shear determination part 13 Temperature detection apparatus 20 Heating apparatus A, A 'Shear coefficient F Shear load prediction value Fx Limit shear load TS Tensile strength (alpha) Shear temperature

Claims (5)

In the method for determining whether shearing is possible or not, it is determined whether the steel plate being conveyed can be sheared by a shearing device.
For each shear candidate steel plate, temperature shear information that is a relationship between the shear temperature and the coefficient A, which is the temperature at the time of shearing of the target steel plate, is obtained in advance.
Shearability determination characterized by determining whether or not shearing is possible based on the coefficient A obtained from the actual shearing temperature of the steel plate as a shearing candidate and the temperature shearing information obtained in advance and the following equation (1). Method.
F = A · t ² · TS / tan θ (1)
here,
F: Shear load prediction value A: Coefficient for shearing t: Plate thickness of steel plate TS: Tensile strength of steel plate θ: Shear rake angle   A coefficient A corresponding to the shear temperature is obtained from the actual shear temperature of the target steel plate based on the temperature shear information obtained in advance, and a shear load predicted value F is obtained using the obtained coefficient A, and the obtained value is obtained. 2. The shearability determination method according to claim 1, wherein whether or not shearing is possible is determined based on the predicted shear load value F.   A method for producing a steel plate, comprising: shearing a steel plate determined to be shearable by the shearability determination method according to claim 1 or 2 with the shearing device. A shearing equipment for shearing a steel plate being conveyed by a shearing device,
A shear determination unit that determines whether or not shearing is possible by the shearability determination method according to claim 1 or 2,
A steel plate shearing facility, wherein the steel plate is sheared when it is determined by the shear determination unit that shearing is possible. In addition to the shear determination unit,
A heating device disposed upstream of the shearing device and capable of increasing the temperature of the steel plate during shearing;
5. The steel sheet shearing equipment according to claim 4, wherein when the steel sheet can be sheared when heated based on the determination of the shear determination unit, the steel sheet is heated to a temperature at which the steel sheet can be sheared.

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