JP2008272807A - Method for determining pre-forming condition of slab - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for determining a pre-forming condition of a slab capable of avoiding an increase of the size or the capacity of an apparatus caused by excessive load during the pressing and breakage of the apparatus, and minimizing the length of a projecting part generated on fore and rear ends of the slab after completing the horizontal rolling to be performed after the pre-forming. <P>SOLUTION: In the method for determining the pre-forming condition of the slab, both ends 13, 14 in the conveying direction of the slab 10 are pressed to form parallel portions 17, 18 by dies 11, 12 arranged opposite to each other in the width direction of the slab 10, and the slab is subjected to edging along the conveying direction. The method includes a stage number determining step of setting the stage number of the parallel portions 17, 18 based on the edging amount of the dies 11, 12 by a stage number determining means, a pressing condition calculation step of calculating the edging amount of the slab 10 by the dies 11, 12 and the contact length of pressing parts 20, 21 by a pressing condition calculating means, and a condition determining step of obtaining the operational condition from the estimated value of the length of projecting parts formed on the ends 13, 14 of the slab 10 and its set value by a condition determining means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a method for determining slab pre-molding conditions for performing width reduction in a slab transport direction by a rolling roll after performing pre-molding by pressing both ends in the transport direction of the slab with a mold.

Conventionally, after performing width rolling in the conveying direction of the slab by a press device (press type width reduction device) provided with a pair of molds arranged on both sides in the width direction of the slab, the rolling and horizontal rolling are combined. One or both of rolling in the width direction and the thickness direction of the slab are performed by a sizing mill device (roll type width reduction device). In this case, a tongue-like or fishtail-like deformation (protrusion) called crop deformation occurs at the front and rear end portions of the slab to be finally produced, and this portion is a loss that does not become a product.
Therefore, as a method for solving this problem, a pre-forming press method for the slab leading and trailing ends by a press device has been invented, and for example, methods of Patent Documents 1 and 2 have been proposed in order to shorten the crop deformation length. Specifically, it is a derivation method and a setting method of the pre-forming press condition using the pressing portion contact length of the mold with respect to the slab at the time of pressing or the width reduction amount of the slab by pressing as a parameter.

JP-A-56-114561 JP 62-267002 A

However, since these methods do not incorporate the conditions and logic (formula) of the load generated during pressing, when the load during pressing is derived separately, the method of Patent Document 1 gives 4000 ton weight, Moreover, in the method of patent document 2, it may exceed 5000 ton weight.
For this reason, in these methods, it is not possible to avoid an increase in the size and capacity of the press device, and it is not possible to make maximum use of the facility capacity under press conditions that vary according to the shape of the product.
In addition, when the load prediction at the time of pressing is not performed, there is a possibility that the equipment is destroyed due to an excessive load at the time of pressing. Even when load prediction is performed separately, the pre-calculation press condition derived in the initial stage may not be applied, and recalculation may be forced.

The present invention has been made in view of such circumstances, and can avoid an increase in equipment size, capacity, and equipment damage due to excessive load during pressing, and the slab leading and trailing ends after completion of horizontal rolling performed after pre-forming. It is an object of the present invention to provide a method for determining pre-forming conditions for a slab capable of minimizing the length of a protruding portion generated in the slab.

The present invention is for solving the above-mentioned problems, and the means (1) is disposed opposite to both sides in the width direction of the slab, and is provided so as to be connected to the pressing portion parallel to the side surface of the slab and the pressing portion. A pair of molds provided with inclined portions are pressed at both ends in the transport direction of the slab to form one or a plurality of parallel portions connected by oblique sides, and the slab is moved in the transport direction. After pre-forming to reduce the width toward both ends, the slab pre-forming conditions for reducing the width of the slab across the conveying direction of the slab by the rolling rolls opposed to both sides of the slab in the width direction A decision method,
When the stage number determining means compares the preset final width of the slab with the upper limit value of the width reduction possible amount of the slab by the mold, and the final width of the slab is equal to or less than the upper limit value of the possible width reduction quantity , A step number determining step of setting the number of steps of the parallel portion to one step;
The pressing condition calculation means satisfies the final width of the slab not more than the upper limit value of the width reduction load of the slab by the mold, not more than the length that allows the pressing portion of the mold to contact the slab. A pressing condition calculation step of calculating a width reduction amount of the slab by the mold and a contact length of the pressing portion of the mold at the time of the width reduction;
A protrusion formed at the end in the conveyance direction of the slab from the width reduction amount of the mold calculated in the pressing condition calculation step and the contact length of the pressing portion of the mold during the width reduction by the condition determining means And a condition determining step using this condition as an operating condition when the predicted value of the protruding portion is equal to or less than a preset value of the length of the protruding portion of the slab set in advance.

The means (2) includes a pair of molds that are disposed opposite to both sides in the width direction of the slab, and each includes a pressing portion that is parallel to the side surface of the slab and an inclined portion that is connected to the pressing portion. After pressing the both ends in the conveying direction, forming a plurality of parallel portions sequentially connected at the hypotenuse, and performing pre-forming to reduce the width of the slab toward both ends in the conveying direction, the width direction of the slab A method for determining slab pre-forming conditions for reducing the width of the slab across the conveying direction of the slab by a rolling roll arranged opposite to both sides,
When the stage width determining means compares the preset final width of the slab with the upper limit of the width reduction possible amount of the slab by the mold, and the final width of the slab exceeds the upper limit of the width reduction possible quantity , A step number determining step for setting the number of steps of the parallel part to a plurality of steps;
The preliminary pressing condition calculation means sets the width reduction amount of the slab by the mold as an upper limit value, sets the width reduction load of the slab by the mold as an upper limit value or less, and sets the contact length of the pressing portion of the mold as the The parallel part excluding the final stage is calculated by calculating the width reduction amount of the slab by the mold and the contact length of the pressing part of the mold at the time of the width reduction satisfying the length that can be contacted with the slab or less A preliminary pressing condition calculation step for determining the width reduction condition of
The pressing condition calculation means satisfies the final width of the slab not more than the upper limit value of the width reduction load of the slab by the mold, not more than the length that allows the pressing portion of the mold to contact the slab. A pressing condition calculation step of calculating a width reduction amount of the slab by the mold and a contact length of the pressing portion of the mold at the time of the width reduction, and determining a width reduction condition of the parallel portion of the final stage;
A protrusion formed at the end in the conveyance direction of the slab from the width reduction amount of the mold calculated in the pressing condition calculation step and the contact length of the pressing portion of the mold during the width reduction by the condition determining means And a condition determining step using this condition as an operating condition when the predicted value of the protruding portion is equal to or less than a preset value of the length of the protruding portion of the slab set in advance.

In the means (3), in the means (1) and means (2), in the condition determining step, the predicted value of the length of the protruding portion formed at the end portion in the transport direction of the slab is a preset value of the slab. When the set value of the length of the protruding portion is exceeded, the contact length of the pressed portion is recalculated in the pressing condition calculating step so that the predicted value is not more than the set value.
Means (4) in means (1) to (3), in the pressing condition calculation step, the width reduction amount of the slab by the mold and the contact length of the pressing portion of the mold during the width reduction. After calculating, the amount of bulging that occurs in the width direction of the slab is calculated by rolling in the thickness direction of the slab when the slab is width-rolled by the rolling roll, and the width reduction condition of the parallel part is calculated. calculate.

The method for determining slab pre-molding conditions according to the present invention includes a step number determining step for setting the number of steps of the parallel portion, so that the contact area between the slab and the mold is excessively increased by selecting the number of steps of the parallel portion. It is possible to set the conditions for pressing without doing. Moreover, since it has the press condition calculation process which calculates the contact length of the press part of the metal mold | die at the time of the width reduction of the slab by a metal mold | die, the conditions which can perform width reduction within the range of equipment capability can be set. And since it has a condition determination process that determines the operating conditions under the width reduction based on the predicted length of the protrusion formed on the slab, it is possible to reduce non-product loss and to reduce the width of the slab with a high yield. Conditions can be obtained.
This avoids equipment enlargement, capacity increase, and equipment destruction due to excessive load during pre-forming, and the length of the protrusion that occurs at the end of the slab tip after the end of horizontal rolling after pre-forming. It is possible to obtain a condition that can minimize the thickness.

In addition, in order to pre-form a plurality of parallel portions, when a preliminary pressing condition calculation step is provided before the pressing condition calculation step, other parallel portions other than the final step can be formed with the maximum capacity of the equipment. Further, it is possible to prevent an excessive increase in the number of steps forming the parallel portion, and to improve productivity.
And, in the condition determination step, when the predicted value of the length of the protrusion exceeds the set value, when recalculating the contact length of the pressing portion, without excessively increasing the length of the parallel portion, Conditions that can reduce product loss as much as possible can be set.
Further, in the pressing condition calculation step, the amount of bulging that occurs in the width direction of the slab is calculated by rolling in the thickness direction of the slab that is performed when the slab is subjected to width reduction by the rolling roll to calculate the width reduction condition of the parallel portion. In some cases, a slab with high dimensional accuracy can be formed.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Here, FIGS. 1 to 4 are flowcharts of a method for determining slab pre-forming conditions according to an embodiment of the present invention, FIG. 5 is a perspective view of a press apparatus to which the method for determining pre-forming conditions for the slab is applied, 6 (A) and 6 (B) are explanatory views of the method for reducing the width of the slab by the same pressing device, FIG. 7 (A) is a plan view of the slab after performing the stop one-stage press, and FIG. FIG. 8 is an explanatory diagram showing the relationship between the press load and the final crop length formed on the slab, and FIG. 8 is an explanatory diagram of the slab after being pressed by the press device and the slab after the horizontal rolling.

As shown in FIG. 1 to FIG. 6, a method for determining slab pre-molding conditions according to an embodiment of the present invention uses a pair of molds 11, 12 disposed opposite to each other in the width direction of a slab 10. 10. Both end portions (that is, the front end portion and the rear end portion) 13 and 14 in the conveyance direction are pressed to form parallel portions 17 and 18 connected by the hypotenuse portions 15 and 16 in one step (may be a plurality of steps). The slab 10 is then preformed to reduce the width toward both ends (front end and rear end) in the transport direction, and then the slab 10 is transported by a rolling roll (not shown) disposed opposite to both sides of the slab 10 in the width direction. This is a method for determining a condition for reducing the width of the slab 10 in the direction. Hereinafter, after describing a press device (hereinafter also referred to as an SP device) 19 used in the present embodiment, a method for determining slab pre-molding conditions according to an embodiment of the present invention will be described.

The press device 19 shown in FIG. 5 is a conventionally known one. The molds 11 and 12 provided in the pressing device 19 have a trapezoidal shape in plan view, and are connected to the pressing portions 20 and 21 parallel to both side surfaces of the slab 10 and the pressing portions 20 and 21, respectively. And inclined portions 22 and 23 provided. The distance between the inclined parts 22 and 23 which oppose is formed so that it may become narrow gradually in the conveyance direction of the slab 10, and the press parts 20 and 21 are provided in the conveyance direction side rather than the inclination parts 22 and 23, respectively. In addition, it has the press part parallel to the both sides | surfaces of the slab 10 under the metal mold | die 11 and 12 shown in FIG. 5, and between the opposing inclined parts provided in connection with this press part. Are placed so as to be gradually narrowed in the opposite direction to the inclined portions 22 and 23.
Thereby, the longitudinal direction both ends of the slab 10 can be width-reduced only by switching the metal mold | dies 11 and 12 and the metal mold | die arrange | positioned under it, respectively.

At the bases of the molds 11 and 12, tip portions of cylinder rods 26 and 27 constituting the width adjusting devices 24 and 25 are attached. The cylinder rods 26 and 27 are attached to the cylinders 28 and 29 so as to be reciprocally movable in the width direction of the slab 10 via a worm mechanism. By rotating the worm from the outside, 12 intervals can be adjusted.
Further, main crank devices 30 and 31 are connected to the base end portions of the cylinders 28 and 29 of the width adjusting devices 24 and 25, and the molds 11 and 12 are directed toward both ends in the width direction of the slab 10. Is configured such that a rolling force can be applied to the slab 10.

The middle part of the opposing molds 11 and 12 has a lower roll (not shown) for supporting the slab 10 from below and a buckling prevention roll 32 for restraining from the upper side. Further, in order to send the slab 10 to the molds 11 and 12 by a predetermined amount on the upstream side of the lower roll and the buckling prevention roll 32, a pinch roll 33 is provided which is disposed with the slab 10 sandwiched in the thickness direction. Yes. The pinch roll 33 includes an upper roll 34 that can be rotated and disposed above the slab 10, and a lower roll 35 that is disposed below the slab 10. In addition, you may provide a pinch roll further in the downstream of the roll 32 for buckling prevention.
Using this press device 19, the preforming shown in FIGS. 6 (A) and 6 (B) is performed.

First, as shown in FIG. 6A, the slab 10 is pressed by the molds 11 and 12 of the press device 19 to form the preliminary parallel portion 36.
As shown in FIG. 6 (A), the preliminary parallel portion 36 is used a plurality of times (here, with respect to the end portion of the slab 10 using the molds 11 and 12 in a state where the conveyance of the slab 10 is stopped. 3 times) After repeated press (hereinafter also referred to as stop press), the slab 10 is further conveyed, and the press position is shifted to the rear side multiple times (here, 3 times) repeatedly pressed (hereinafter also referred to as running press). Can be formed. The slab 10 is pressed between the slabs 10 by a predetermined distance (of the dies 11 and 12) so that the slab 10 has the same width as the slab 10 formed by the first stop press. After transporting (within the range of the lengths of the pressing parts 20 and 21), the operation of stopping and performing a certain amount of pressing by the molds 11 and 12 is repeated.

Further, as shown in FIG. 6B, the preliminary parallel portion 36 stops after conveying the slab 10 for a predetermined distance (within the length of the pressing portions 20 and 21 of the molds 11 and 12), The operation of pressing a predetermined amount by the molds 11 and 12 according to the width of the preliminary parallel portion 36 is performed a plurality of times (here, 7 times) while the slab 10 is moved and the pressing position is shifted to the rear side. It may be repeated (this is also a running press).
Thus, after forming the preliminary | backup parallel part 36 with respect to the slab 10, it presses further with respect to this preliminary | backup parallel part 36. FIG. Thereby, the parallel part 17 connected by the hypotenuse part 15 is formed. The parallel portion 18 can be molded by the same method.
Then, the preformed slab is reduced in width over its entire length by a sizing mill device (hereinafter also referred to as SM device) provided with a roll for reduction arranged opposite to the slab. This sizing mill device is a conventionally known sizing device, and two pairs (or a plurality of pairs) of rolling rolls arranged at intervals in the slab conveying direction and opposed to each other on both sides in the thickness direction of the slab. And a rolling roll that can be horizontally rolled.

Here, the operation restrictions of the press apparatus 19 shown above are demonstrated, referring FIG. 7 (A) and (B).
FIG. 7A is a plan view of the slab when the stop press is performed on the slab, and one stage of the parallel portion is formed on the slab (the stop one-step press is performed), and FIG. In the pre-forming press using a press device, the final pressing amount of pressing width (desired width killing amount) is fixed (constant), and the press pressing part length (hereinafter also referred to as mold pressing part contact length) is used as a parameter. It is the conceptual diagram which showed the relationship between the crop length (namely, protrusion part length) of a typical slab edge, and the load at the time of a press, the geometric contact length limit of the press part of a metal mold | die, and equipment (apparatus) The load limit is also shown.

As can be seen from FIG. 7B, when the mold pressing part contact length is increased during pre-forming pressing, the final slab end crop length decreases, but conversely the pressing load increases. Will be. For this reason, it is not possible to set the mold pressing portion contact length exceeding the load limit of the equipment, only by reducing the crop length.
Moreover, even if the load at the time of pressing is within the load limit of the equipment, setting beyond the geometric contact length limit of the pressing portion of the mold cannot be performed.
In other words, constraints due to the load limit of the equipment and the geometric contact length limit of the die pressing part are incorporated in the logic that determines the pre-forming press condition that minimizes the final crop length of the slab end. You can see that it has to be.

Moreover, in FIG. 8, the conceptual diagram of the deformation | transformation of the slab end part at the time of the preforming press by a press apparatus and the conceptual diagram of the deformation | transformation of the slab end part after the horizontal rolling implemented after a preforming press are shown.
The deformation of the slab end after the pre-forming press causes a fishtail-shaped crop deformation near the width end of the slab in plan view and increases in the thickness direction of the slab near the center of the width of the slab when viewed from the front. Meat deformation occurs.
From this variant, when horizontal rolling is performed after preforming the slab, the thickened portion near the center of the width of the slab is rolled and the fishtail-like crop length is relatively reduced while the metal in the width direction is reduced. The flow causes an increase in the slab width. Here, the change in the crop length and the amount of increase in width vary depending on the pre-forming press conditions.
In other words, in order to finally obtain the desired slag width, the prediction of the width return amount during horizontal rolling that changes according to the pre-forming press conditions must be incorporated in the press condition setting logic for pre-forming. I understand.

Based on the above matters, a method for determining slab preforming conditions according to an embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the method for determining slab pre-forming conditions is carried out using a slab pre-forming condition determining device (hereinafter also simply referred to as a determining device). This determining device has a stage number determining means, a preliminary pressing condition calculating means, a pressing condition calculating means, a condition determining means, and a storage means, and each means is constituted by, for example, a program installed in a computer. Yes. The determination device is also connected to the control device of the press device 19, and is obtained by the determination device based on, for example, conditions input using input means (for example, a keyboard and a mouse) operated by an operator. The press device can be controlled under certain conditions.

As shown in FIG. 1, first, in step 1 (ST1), the operator inputs the slab condition to the determination device by the input means and stores it in the storage means.
These conditions are the initial width, initial thickness, material, temperature, final target width, and final target (target value) crop length of the slab.
Subsequently, in step 2 (ST2), the press machine capacity condition is input and stored in the storage means.
This capability condition is the pressing part limit length of the mold (the length of the pressing part), the taper angle of the mold (the angle θ formed between the side surface of the slab and the contact surface of the inclined part of the mold), and one step press The critical reduction amount and the critical load of the press.
Note that this data is a value unique to the equipment. For example, if there is no change in equipment conditions such as a change in mold, the data can be saved in a memory (storage means) or the like, thereby saving the trouble of inputting each time. Is possible.

Based on the above input conditions, in step 3 (ST3), the number of parallel portions formed in the slab is determined by the step number determining means. Specifically, the input preset final width of the slab, that is, the target slab width reduction amount, and the upper limit of the slab width reduction amount based on the mold geometry, that is, the critical reduction in the one-stage press Compare the amount. The single width reduction amount means the reduction amount on one side of the slab in the width direction (hereinafter the same).
Here, when the target width reduction amount of the slab is equal to or less than the limit reduction amount in the one-stage press, the number of steps of the parallel portion is set to one step, this is stored in the storage means, and the process proceeds to Step 4 (ST4).
On the other hand, if the target slab width reduction amount exceeds the limit reduction amount in the one-stage press, the number of parallel portion stages is set to a plurality of stages, which are stored in the storage means, and the process proceeds to step 20 (ST20).
Thereby, the number of steps of the parallel portion formed by the pressing device is determined (the step number determining step).

As described above, when the number of steps of the parallel portion is set to one step, in step 4, a mode for performing the stop one-step press is determined (corresponding to the first half portion of FIG. 6A).
In step 5 (ST5), the pressing condition calculation means derives a function of the press piece width reduction amount obtained by correcting the slab width return amount by horizontal rolling of the SM apparatus, and stores it in the storage means. This function is expressed by, for example, Expression (1).
dW = {f ₁ −Sqrt [f ₂ ² −4f ₃ (dWsm + f ₄ )]} / (2f ₅ ) (1)
_{f 1 = 1-c 10 -c} 11 x-c 12 x 2 -c 13 y-c 14 xy-c 15 x 2 y-c 16 y 2 -c 17 xy 2 -c 18 x 2 y 2
f ₂ = −1 + c ₁₀ + c ₁₁ x + c ₁₂ x ² + c ₁₃ y + c ₁₄ xy + c ₁₅ x ² y + c ₁₆ y ² + c ₁₇ xy ² + c ₁₈ x ² y ²
f ₃ = c ₁₉ + c ₂₀ xc ₂₁ x ² + c ₂₂ y + c ₂₃ xy + c ₂₄ x ² y + c ₂₅ y ² + c ₂₆ xy ² + c ₂₇ x ² y ²
f ₄ = c ₁ + c ₂ x + c ₃ x ² + c ₄ y + c ₅ xy + c ₆ x ² y + c ₇ y ² + c ₈ xy ² + c ₉ x ² y ²
f ₅ = c ₁₉ + c ₂₀ x + c ₂₁ x ² + c ₂₂ y + c ₂₃ xy + c ₂₄ x ² y + c ₂₅ y ² + c ₂₆ xy ² + c ₂₇ x ² y ²
Here, dW is the pressing piece width reduction amount corrected for the slab width return amount, c _{1 to} c ₂₇ are constants, x is the number of presses during running, y is the die pressing portion contact length (parallel portion length), and dWsm is the slab final length. The target width reduction amount is shown respectively.

In step 6 (ST6), a pressing load calculation function is derived from the pressing amount, the die pressing portion contact length, the slab physical property, and the slab size by the pressing condition calculation unit, and stored in the storage unit. This function is expressed by, for example, Expression (2).
p = kmp · h0 · Qp · y + (dW / Tan [taper]) · G (2)
Here, kmp is the steel material deformation resistance, h0 is the slab thickness, Qp is the rolling force function, y is the die pressing portion contact length (parallel portion length), dW is the pressing piece width rolling amount, taper is the die taper angle, and G is Steel grade coefficients are shown respectively.

As shown in FIG. 2, in step 7 (ST7), the pressing condition calculation means calculates the press piece width reduction amount function derived in step 5, the press load prediction function derived in step 6, and the press input in step 2. The mold pressing part contact length is derived from the limit load and stored in the storage means.
In step 8 (ST8), the pressing condition calculation means confirms the mold pressing portion contact length. Specifically, the mold pressing part contact length is compared with the mold pressing part limit length.
Here, if the mold pressing portion contact length is equal to or shorter than the mold pressing portion limit length, the mold pressing portion contact length is stored in the storage means, and the process proceeds to Step 10 (ST10).
On the other hand, if the mold pressing part contact length is longer than the mold pressing part limit length, in step 9 (ST9), the mold pressing part contact length is changed to the mold pressing part limit length, and this is stored in the storage means. , Go to Step 10.

In step 10, the pressing condition calculation means derives a pressing piece width reduction amount that corrects the slab width return amount by horizontal rolling of the SM device based on the die pressing portion contact length (or die pressing portion limit length). Is stored in the storage means. This function uses, for example, the above-described equation (1).
Thus, after calculating the width reduction amount of the slab by the mold and the contact length of the pressing portion of the mold at the time of the width reduction, the swelling generated in the width direction of the slab by rolling in the thickness direction of the slab performed by the SM apparatus By calculating the amount and calculating the width reduction condition of the parallel portion, it is possible to improve the dimensional accuracy of the slab subjected to the width reduction.
By the above method, the slab of the slab by the mold satisfying the final width of the slab which is less than the upper limit value of the width reduction load of the slab by the mold and less than the length that can be contacted with the slab of the pressing part of the mold. The width reduction amount and the contact length of the pressing portion of the mold at the time of width reduction can be calculated (the pressing condition calculation step).

In step 11 (ST11), the condition determining means derives a prediction function for predicting the final crop length of the slab from the press piece width reduction amount and the die pressing portion contact length derived in step 10, and stores them in the storage means. . This function is expressed by, for example, Expression (3).
crop = (d ₁ x ² + d ₂ x + d ₃ ) (d ₄ y ² + d ₅ y + d ₆ ) (d ₇ dW ² + d ₈ dW + d ₉ )
... (3)
Here, d ₁ to d ₉ is a constant, x is an inter-running pressing number, y is the mold pressing portion contact length (parallel Director), dW is a pressing piece width reduction rate, respectively.
In step 12 (ST12), the final slab crop length is confirmed by the condition determining means. Specifically, it is examined whether or not the predicted value of the final slab crop length and the set value of the final target crop length of the slab are substantially equal (for example, within ± 10% of the predicted value).

Here, if the predicted value and the set value are substantially equal, in step 14 (ST14), the press condition as the operation condition is determined and stored in the storage means.
On the other hand, if the predicted value exceeds the set value, the process proceeds to step 13 (ST13), the running press is performed, and the number of executions is changed (mode of stop 1-step press and running press) (FIG. 6A). )reference). Note that the upper limit of the number of executions of the running press may be adjusted in consideration of the margin of the operating time at each time, and the upper limit of the number of executions of the running press and the required crop length are determined by the operator as appropriate. (Condition determining step).
And operation of above-mentioned step 5-step 12 is repeatedly implemented, and the contact length of a press part is recalculated so that a predicted value may be below a preset value.

Here, in step 3 described above, the case where the target slab width reduction amount exceeds the limit reduction amount in the one-stage press will be described with reference to FIGS. 3 and 4. Detailed description of the same parts as those in FIGS. 1 and 2 will be omitted.
In step 20 (ST20), the mode is determined to perform the stop 1-stage press, the running press, and the stop 2-stage press (corresponding to FIG. 6A). Here, the stop two-stage press means that the preliminary parallel portion 36 formed on the slab is further pressed by the stop one-stage press and the running press.

In step 21 (ST21), the preliminary pressing condition calculation means sets the press piece width reduction amount at the time of the first stop press to the one-stage press limit reduction amount (the width of the slab by the mold) that is the upper limit of the press device capacity. The upper limit value of the reduction amount is set and stored in the storage means, and the process proceeds to step 22 (ST22).
In step 22, the press load prediction function is derived by the preliminary pressing condition calculation means in the same manner as in step 6 described above, and is stored in the storage means.
In step 23 (ST23), the pre-pressing condition calculation means derives the die pressing portion contact length from the press piece width reduction amount obtained in step 21, the press load prediction function derived in step 22, and the press limit load. And stored in the storage means.

In step 24 (ST24), the pre-pressing condition calculating means confirms the mold pressing portion contact length. Specifically, the mold pressing part contact length is compared with the mold pressing part limit length.
Here, if the mold pressing part contact length is equal to or less than the mold pressing part limit length, this mold pressing part contact length is determined as a stop 1-step press condition and stored in the storage means (step 26 (ST26)). ), Go to Step 27 (ST27).
On the other hand, if the mold pressing part contact length is longer than the mold pressing part limit length, the mold pressing part contact length is changed to the mold pressing part limit length in step 25 (ST25), and this is stored in the storage means. , Go to Step 26.

Further, in step 27 (ST27), based on the mold pressing portion contact length, the condition of the running press is determined so as to obtain the length of the preliminary parallel portion to be formed, and stored in the storage means. Go to ST28).
Thereby, the width reduction conditions of the parallel part excluding the last stage can be determined (preliminary pressing condition calculation step).
Then, the operation from step 28 to step 34 (ST34) is performed by the pressing condition calculation means and the condition determination means, and the conditions for the stop two-stage press are determined. Steps 28 to 34 are basically the same as the operations of steps 5 to 11 described above, and thus description thereof is omitted.

In step 35 (ST35), the final crop length of the slab is confirmed by the condition determining means. Specifically, it is examined whether or not the predicted value of the final slab crop length and the set value of the final target crop length of the slab are substantially equal (for example, within ± 10% of the predicted value).
Here, if the predicted value and the set value are substantially equal, in step 37 (ST37), the press condition is determined and stored in the storage means.
On the other hand, if the predicted value exceeds the set value, the process proceeds to step 36, and the running press is performed, and the number of times of execution is changed (stop 1-stage press, running press, stop 2-stage press, running press mode). (See FIG. 6A). Note that the upper limit of the number of executions of the running press may be adjusted in consideration of the margin of the operating time at each time, and the upper limit of the number of executions of the running press and the required crop length are determined by the operator as appropriate. Also good.
And operation of above-mentioned step 28-step 35 is repeatedly implemented, and the contact length of a press part is recalculated so that a predicted value may become below a setting value.

By the above operation, for example, a press pattern (for example, stop 1 step press, stop 1 step press and running press, stop 1 step press and running press and stop 2 press, or stop 1 step press and running press) Stop two-stage press and running press), press piece width reduction amount at the time of stop one-stage press, and mold pressing part contact length are obtained, and the press device is controlled under these conditions.
As described above, according to the press condition setting at the pre-forming press, the load limit and the geometric limit of the press device are satisfied, and finally the crop length generated at the front and rear ends of the slab is minimized. Is possible. Furthermore, by defining the load limit of the press device, it is not necessary to ensure an excessive device capacity, and thus the press device can be reduced in size.

Next, examples carried out for confirming the effects of the present invention will be described.
FIG. 9 shows a result of deriving conditions for pre-forming the end portion of the slab with a press device in order to reduce the width of the slab.
The slab used has an initial width of 1900 mm, an initial thickness of 282 mm, and a temperature of 1100 ° C. Moreover, the press apparatus used has a geometric contact length limit of 350 mm for the pressing part of the mold, and a limit load of the equipment is 1900 tons.

Based on these, the desired slab piece width reduction amount is set to 150 mm, the set crop length is set to 30 mm or less, and the desired slab piece width reduction amount under the condition that the geometric single width reduction limit during stop press is 175 mm ( Desired final slab width = initial slab width-2 x slab piece width reduction amount) Press piece width reduction amount, die pressing part contact length at the time of pressing, and final slab end crop length Asked.
As a result, the press pattern was a combination of a stop 1-stage press and a running press, and the running press was performed twice. In addition, by setting the conditions that the single-sided press amount at the time of the first stop press is about 156 mm and the mold pressing part contact length is 350 mm, the final slab end crop length is about 25 mm, which satisfies the above setting. It could be confirmed.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above-described embodiment, and the matters described in the claims are not limited. Other embodiments and modifications conceivable within the scope are also included. For example, the case where the method for determining the slab pre-molding conditions of the present invention is configured by combining some or all of the above-described embodiments and modifications is also included in the scope of the right of the present invention.

It is a flowchart of the determination method of the preforming conditions of the slab which concerns on one embodiment of this invention. It is a flowchart of the determination method of the preforming conditions of the slab. It is a flowchart of the determination method of the preforming conditions of the slab. It is a flowchart of the determination method of the preforming conditions of the slab. It is a perspective view of the press apparatus which applies the determination method of the preforming conditions of the slab. (A), (B) is explanatory drawing of the width reduction method of the slab by the same press apparatus, respectively. (A) is a top view of the slab after performing the stop 1 step | paragraph press, (B) is explanatory drawing which shows the relationship between the press load with respect to a slab, and the last crop length formed in a slab. It is explanatory drawing of the slab after the press by the press apparatus, and the slab which performed horizontal rolling after that. It is explanatory drawing which shows the width reduction process of the slab which concerns on an Example.

Explanation of symbols

10: Slab, 11, 12: Mold, 13, 14: End, 15, 16: Oblique side, 17, 18: Parallel part, 19: Press device, 20, 21: Press part, 22, 23: Inclined part 24, 25: Width adjusting device, 26, 27: Cylinder rod, 28, 29: Cylinder, 30, 31: Main crank device, 32: Buckling prevention roll, 33: Pinch roll, 34: Upper roll, 35: Lower roll, 36: preliminary parallel part

Claims (4)

Oppositely arranged on both sides in the width direction of the slab, a pair of molds provided with a pressing portion parallel to the side surface of the slab and an inclined portion connected to the pressing portion, both ends in the transport direction of the slab are Each is pressed to form one or more parallel parts connected at the hypotenuse, and after pre-forming the slab to be reduced in width across the conveying direction, it is placed facing both sides of the slab in the width direction. A method for determining a pre-forming condition of a slab for reducing the width of the slab across the conveying direction of the slab by a rolled roll for reduction,
When the stage number determining means compares the preset final width of the slab with the upper limit value of the width reduction possible amount of the slab by the mold, and the final width of the slab is equal to or less than the upper limit value of the possible width reduction quantity , A step number determining step of setting the number of steps of the parallel portion to one step;
The pressing condition calculation means satisfies the final width of the slab not more than the upper limit value of the width reduction load of the slab by the mold, not more than the length that allows the pressing portion of the mold to contact the slab. A pressing condition calculation step of calculating a width reduction amount of the slab by the mold and a contact length of the pressing portion of the mold at the time of the width reduction;
A protrusion formed at the end in the conveyance direction of the slab from the width reduction amount of the mold calculated in the pressing condition calculation step and the contact length of the pressing portion of the mold during the width reduction by the condition determining means And a condition determining step using this condition as an operating condition when the length of the protrusion is predicted and the predicted value of the protrusion is equal to or less than the preset value of the length of the protrusion of the slab. To determine the pre-forming conditions of the slab to be used. Oppositely arranged on both sides in the width direction of the slab, a pair of molds provided with a pressing portion parallel to the side surface of the slab and an inclined portion connected to the pressing portion, both ends in the transport direction of the slab are Each was pressed to form a plurality of parallel portions sequentially connected at the oblique sides, and after pre-forming the slab to be reduced in width toward both ends in the conveying direction, the slabs were arranged opposite to each other in the width direction. A method for determining slab pre-molding conditions for reducing the width of the slab across the conveying direction of the slab by a rolling roll,
When the stage width determining means compares the preset final width of the slab with the upper limit of the width reduction possible amount of the slab by the mold, and the final width of the slab exceeds the upper limit of the width reduction possible quantity , A step number determining step for setting the number of steps of the parallel part to a plurality of steps;
The preliminary pressing condition calculating means sets the width reduction amount of the slab by the mold as an upper limit value, sets the width reduction load of the slab by the mold as an upper limit value or less, and sets the contact length of the pressing portion of the mold as the The parallel part excluding the final stage is calculated by calculating the width reduction amount of the slab by the mold and the contact length of the pressing part of the mold at the time of the width reduction satisfying the length that can be contacted with the slab or less A preliminary pressing condition calculation step for determining the width reduction condition of
The pressing condition calculation means satisfies the final width of the slab not more than the upper limit value of the width reduction load of the slab by the mold, not more than the length that allows the pressing portion of the mold to contact the slab. A pressing condition calculation step of calculating a width reduction amount of the slab by the mold and a contact length of the pressing portion of the mold at the time of the width reduction, and determining a width reduction condition of the parallel portion of the final stage;
A protrusion formed at the end in the conveyance direction of the slab from the width reduction amount of the mold calculated in the pressing condition calculation step and the contact length of the pressing portion of the mold during the width reduction by the condition determining means And a condition determining step using this condition as an operating condition when the length of the protrusion is predicted and the predicted value of the protrusion is equal to or less than the preset value of the length of the protrusion of the slab. To determine the pre-forming conditions of the slab to be used. In the determination method of the slab pre-forming conditions according to any one of claims 1 and 2, in the condition determination step, the predicted value of the length of the protruding portion formed at the end portion in the transport direction of the slab, When the preset value of the length of the protruding portion of the slab exceeds the preset value, in the pressing condition calculation step, the contact length of the pressing portion is recalculated so that the predicted value is not more than the set value. A method for determining a pre-forming condition of a characteristic slab. In the determination method of the pre-forming conditions of the slab of any one of Claims 1-3, in the said press condition calculation process, the width reduction amount of the said slab by the said metal mold | die, and the said mold at the time of this width reduction After calculating the contact length of the pressing portion, by rolling in the thickness direction of the slab that is performed when the slab is reduced in width by the reduction roll, the amount of swelling generated in the width direction of the slab is calculated, A method for determining a slab preforming condition, characterized by calculating a width reduction condition of a parallel portion.

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