JPS63101014A - Rolling method for thick plate - Google Patents

Abstract

PURPOSE:To prevent a defective plate thickness and to execute perfect shape controlling by dividing the transverse direction of a rolled stock to respective positions including both end parts, center and >= 1 points between both ends, calculating the ratio crowns in the respective positions, determining a pass schedule and adjusting a roll gap, bender force, etc. CONSTITUTION:Various sets of information in the target thickness, width, length, crown, target lod, etc., of the rolled stock 1 are inputted from an input device 5 to an arithmetic unit 6. The ratio crowns in the respective positions divided in the transverse direction of the rolled stock are calculated by said unit 6 using a gage meter model. The change rates of the ratio crowns in the respective positions at every pass are calculated and the pass schedule is determined. The plate thickness and shape controllability in the pass schedule and the roll gap, bender force, shift quantity, etc., of each pass are fed to an output device 7 which outputs the various above-mentioned data to execute the rolling of each pass. The generation of the defective plate thickness is prevented and the perfect shape control is executed by the above-mentioned method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thick plate rolling method, particularly to shape control and plate thickness management in consideration of the plate profile in the width direction.

(Prior art) Conventionally, a shape control method in plate rolling in which a material to be rolled is reverse rolled is based on the thickness hc of the center of the width of the rolled material l and the plate thickness FE h- of the edge of the plate, as shown in FIG. Measure the ratio of the difference between the center plate thickness hc and the end plate thickness to the center plate thickness hc,
That is, the ratio crown ΔCr= (hc-h,)/hc
Calculate and control this ratio crown ΔC1 to be constant or within a certain tolerance range for each pass? 111 L,
,ing.

[Problem that the invention seeks to solve]

However, when rolling with a rolling mill equipped with a roll bending function at the end of the work roll shaft, the profile in the width direction is shown in Figure 7 due to the relationship between the width of the rolled material, rolling load, bender force, etc. during lower rolling. It becomes like this. Fig. 7 shows an example of a temporary profile with the distance from the center of the plate width plotted on the horizontal axis; in the figure, A indicates a rolling load P of 5200 tons;
Bender power P.

B is the case where the rolling force P is 5200 tons and the bender force Pg is 600 tons.

As shown in No. 717I, the plate width direction profile may exhibit a quartic curve-like change, and as in the conventional control method, the ratio crown ΔC calculated only from the plate width center plate thickness hc and the edge plate thickness. , it was not possible to capture the above-mentioned local ratio crown change in the sheet width direction in shape control ra that took into consideration the shape control, and complete shape control was impossible.

In addition, in the conventional rolling operation, the control of the plate thickness at the center of the plate width hc and the edge plate thickness is only temporary, as is the case with the calculation of the ratio crown ΔCr, as shown in B in Figure 6. In the case of such a temporary profile, there is a problem that a minimum thickness part exists between the center of the width of the sheet and the end, and there is a risk of producing a material with defective sheet thickness.

This invention has been made to solve these problems, and it is an object of the present invention to propose an l″X temporary rolling method that allows complete shape control and does not cause sheet thickness defects.

[Means for solving problems]

The thick plate rolling method according to the present invention, in plate rolling in which a material to be rolled is reverse rolled, divides the plate radius direction of the rolled material into the center of the rolled material, both ends, and at least one or more positions between the center and both ends, Using the gauge meter model divided into each position, calculate the ratio crown at each position for each pass, and determine the pass schedule by considering changes in the ratio crown at each position (roll gap, bender force, shift)ff1 etc. is adjusted as 1>ffi.

[Effect]

In this invention, the rolled material is rolled while controlling the shape and thickness of the rolled material in consideration of the longitudinal elongation distribution of the rolled material in the width direction of the plate.

〔Example〕

FIG. 1 is a schematic configuration diagram of a rolling mill according to an embodiment of the present invention, in which 1 is a rolled material, 2 is an upper work roll,
3 is a lower work roll, and the upper work roll 2 and the lower work roll 3 are configured to be able to shift in the roll width direction between passes or between bars. 4 is above
These are backup rolls provided above and below the lower work roll 2.3.

5 is an input device for inputting specifications such as target plate thickness, plate width, rolling load, etc.; 6 is an input device for inputting specifications such as target plate thickness, plate width, rolling load, etc., and 6 is a specification input from input device 5 and measured values of roll gap, bender force, shift amount, or plate profile during the previous pass. a calculation device that determines a pass schedule for each pass based on the rolling results such as, and re-corrects the pass schedule for the next pass and subsequent passes based on the rolling results of the previous pass between passes;
is an output device that outputs the roll gap, bender force, shift amount, etc. of each pass according to the pass schedule determined by the calculation device 6.

As shown in FIG. 2, the arithmetic device 6 includes a temporary crown calculation means 8 for calculating a temporary crown, a ratio crown calculation means 9 for calculating a ratio crown from the calculated temporary crown, and an actual result calculated from a rolling result value 13 for each pass. The apparatus includes a memory 10 for storing ratio crowns, a ratio crown change rate calculating means 11 for calculating a ratio crown change rate for each pass from the ratio crown of each pass, and a path schedule determining means 12.

The operation of rolling a thick plate using the rolling mill configured as described above will be explained based on the flowchart shown in FIG. 3.

Here, the gauge model measures the width direction of the rolled material 1 at the center of the rolled material, at least one point or more between both ends and the center and end of the rolled material, for example, the center of the width of the rolled material 1 as shown in FIG. Point C and El at both ends, point E2, point C at the center of the plate width and El at both ends,
Fl, F2, which are each divided into two between two points E. Assume that it is divided into multiple points of CI and 02 points.

First, before starting rolling, the target thickness and width of the rolled material l,
Specification information such as length and crown target load is input from the input device 5 to the calculation device 6 (step 31).

The temporary crown calculation means 8 of the calculation device 6 calculates each point C, E, , F, in the board width direction based on the input conditions.

G = (i = 1.2) using the multi-segmented gauge meter model, determine the approximate path schedule at its representative point (Step 32), and calculate the plate thickness at each point of the multi-segmented gauge model for each pass based on the pass schedule. he
,l1m! + l1ri, h*i (+ -1.

2) and the temporary crowns (h, -h, i), (hc-
hr+) + (hc-ha+), and input the calculated plate thickness and plate crown at each point to the ratio crown calculation means 9.

The ratio crown calculation means 10 calculates a ratio crown expressed by the following formula for each pass from the plate thickness at each point in the sheet width direction and the temporary crown, and outputs it to the ratio crown change rate calculation means 11.

In addition, in formula +11, ΔC, (E), 8C, (F5)ΔC, (Gi) represent the ratio crown at the E8 point, F+ point, and at point, respectively.

The ratio crown change rate calculation means 11 calculates the ratio crown change rate for each pass of each point from the ratio crown of each pass and each point sent from the ratio crown calculation means 9, and outputs it to the path schedule determination means 12. (Step 33
).

The nozzle schedule determining means 12 compares the ratio crown change rate at each point in the board width direction manually inputted, and weights it so that the ratio crown change rate at each point is a constant value or within a predetermined tolerance range. (Step 34), and after determining its acceptability (Step 35), determine the roll gap, heng force, and shift amount for each pass (Step 3).
6).

In addition, the minimum plate thickness in the plate width direction of rolled material 1 and its extent are predicted from the gauge meter model values divided at each point in the plate width direction obtained as the above results, and the plate thickness of the predicted minimum plate thickness part is The roll gap, bender force, shift) ffl of each pass is finely adjusted so that the plate thickness falls within the allowable range determined by the rolling accuracy, lower limit thickness of tolerance, etc. (step 37).

After determining the acceptability of the board thickness, shape controllability, roll gap, bender force, shift amount, and other set values for each pass in the pass schedule determined as described above (step 38), the roll gap for each pass is determined. , vendor power,
The set values such as the shift amount are sent to the output device 7, and the output device 7 sets and outputs the lobe gap, bender force, and shift amount for each pass to perform rolling for each pass (step 39).

Furthermore, between passes, various results such as roll gap, rolling load, bender force, and shift amount are determined for each pass (step 4).
0), the pass schedule for the next pass and subsequent passes is revised again based on these results.

In addition, instead of correcting the pass schedule from actual values such as roll gaps in the inter-pass correction, a temporary profile may be used using a thickness detector such as a T-line thickness meter (◆) as shown in FIG.

In FIG. 5, a plurality of thickness detectors +4 are fixed in the width direction of the plate, or one or more thickness detectors +4 are configured to be movable in the width direction of the plate. This thickness detector 14 measures the thickness of the rolled material 1 at multiple points in the width direction of the rolled material 1 for each pass, and by modifying the pass schedule for the next pass and subsequent passes based on the results, a more perfect shape of the rolled material 1 can be obtained. can be controlled.

〔Effect of the invention〕

In the present invention, as explained above, the rolled material is rolled in consideration of the local ratio crown change in the sheet width direction, so that the shape of the rolled material can be completely controlled.

Furthermore, since the thickness of the rolled material is managed in consideration of the sheet profile in the width direction, it is possible to prevent the occurrence of materials with defective sheet thickness, and it also has the effect of improving yield.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a rolling mill according to an embodiment of the present invention;
FIG. 2 is a block diagram showing the arithmetic device of the above embodiment, and FIG.
The figure is a flowchart showing the operation of the above embodiment, FIG. 4 is an explanatory diagram showing a cross section in the board width direction of the above embodiment, FIG. 5 is a schematic configuration diagram showing another embodiment, and FIG. 6 is an explanation of the conventional example. FIG. 7 is a plate profile distribution diagram. 1...Rolled material, 2...Upper work roll, 3...Lower work roll,
4... Backup roll, 5...
・・・・・・Human powered equipment, 6・・・・・・・・・Arithmetic equipment,
7・・・・・・・・・Output device, +4・・・・・・・・・
・Thickness detector.

Claims (2)

[Claims] (1) In plate rolling where the material to be rolled is reverse rolled,
The width direction of the rolled material plate is divided into the center of the rolled material, both ends, and at least one or more points between the center and both ends, and the ratio crown of each of the above positions for each pass is calculated using a gauge meter model divided into each of the positions. A method for rolling a thick plate, characterized in that the pass schedule is determined by calculating the ratio crown at each position, and the roll gap, bender force, shift amount, etc. are adjusted. (2) The pass schedule is modified in consideration of the plate thickness and position of the minimum plate thickness in the plate width direction calculated by the gauge meter model divided into each position in the plate width direction.
The thick plate rolling method described in .