JPS62197221A - Correcting method for lateral bending of metallic plate - Google Patents

Abstract

PURPOSE:To improve the lateral bending correcting capacity by deriving a correct value of a difference of roller push-in quantities of a work side and a driving side, from a temperature of a metallic plate and a measured value of lateral bending, in a hot flatness straightening machine. CONSTITUTION:A camera 8 and a thermometer 9 are provided, respectively, on a carrying table 3 of a thick steel plate 1 which has been brought to hot rolling. The camera 8 inputs an image of the steel plate 1 passing through right under the camera 8, and a lateral bending quantity is measured through an image storage and an image processing 81, 82. Also, the thermometer 9 measures a temperature of the steel plate 1, and a roller push-in quantity correct value calculation 10 of a work side and a driving side of a straightening machine in accordance with a prescribed expression from the lateral bending quantity,the temperature, a yield stress estimated value obtained from the temperature, dimensions of the steel plate 1, and information 71, 72 of the material. Subsequently, based on this correct push-in quantity, a correction by the straightening machine 5 is executed. The correction can be executed without deteriorating the plate thickness accuracy, therefore, by this method, the lateral bending correcting capacity can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for correcting lateral bending of hot rolled metal sheets using a hot flattening machine.

Conventional technology Metal plates, such as thick steel plates, are manufactured using the equipment shown in FIG.

That is, the steel piece that is the material of the thick steel plate 0) heated and softened in the heating furnace (2) is conveyed to the right in the figure on the conveyance table (3). While being transported, the steel billet is passed through a rough rolling mill (41
) and a finishing mill (42) to form the desired dimensions and then flattened by hot flattening a (c), transferred from the conveyance table (3) to the cooling bed (6) and cooled. It is air-cooled on the floor (6) to obtain a thick steel plate (1). The thick steel plate (1) has some lateral bending (C) as shown in FIG. If the degree of lateral bending (C) is small, there is no practical problem, but if it is large, the thick steel plate (1) may have a rectangular shape as shown by the chain line in Figure 5 even if there is room for the inside and length of the plate. (1) may not be collected. The causes of the horizontal bending (C) are uneven thickness of the raw steel billet, uneven heat in the heating furnace (2), misalignment of the rolling center in the rough rolling mill (41) or finishing rolling a (42), Problems such as poor leveling of the rolling rolls and uneven cooling during rolling are intricately intertwined. Lateral bending caused by these causes (C)
In order to remove this, conventionally the thick steel plate (1) is stretched in the longitudinal direction by creating a gap between the working side and the driving side of the upper and lower rolls in the rough rolling mill (41) or finishing rolling mill (42). Conventionally, a method has been used to generate a lateral curvature that offsets the lateral curvature (C) to be removed by varying the amount along 11.

Purpose of the Invention However, in the above-mentioned rough rolling mill (41) or finishing rolling mill (42), by creating a difference in the gap between the working side and the driving side of the upper and lower rolls, it is possible to stretch a thick steel plate (1) in the longitudinal direction. The method of removing the lateral bending (C) of the thick steel plate (1) by varying the amount along the middle direction simultaneously changes the thickness of the thick steel plate (1) along the middle direction. There is a problem in that there is a limit to its application because of the need to maintain rolling accuracy, and it is not possible to correct the lateral bend (C) that occurs after rolling by the finishing mill (42). The present invention aims to solve such problems.

DESCRIPTION OF THE INVENTION The present invention provides a means for achieving the above object, which measures the lateral bending and temperature of a hot-rolled metal plate, and calculates the respective measured values and the dimensions of the metal plate. Summary of a method for calculating the appropriate value of the difference in roll pushing amount on the working side and drive side of a hot flattening machine based on the material and the material, and correcting horizontal bending of a metal plate using a hot flattening machine based on the proper value. do.

The present invention will be explained based on the drawings. FIG. 1 is a system diagram of the method for correcting horizontal bending of a metal plate according to the present invention. A hot-rolled thick steel plate (1) is conveyed on a conveyance table (3) from the left to the right in FIG. A camera (8) is installed above the transport table (3), and a thick steel plate (1
) input the image. The input image is temporarily stored as an image (81), then subjected to image processing (82) to be converted into a clear image, and then lateral bending is measured (83).

A thermometer (9) is also provided on one side of the conveyance table (3) to manually measure the temperature of the thick steel plate (1) passing directly below. Based on the input, a temperature measurement (91) is performed, and the measured temperature and the thick steel plate (1) are given as process information.
The yield stress is estimated (92) from the material. The lateral bending (C) obtained as a result of the lateral bending measurement (83), the yield stress (σt) obtained as a result of the yield stress estimation (92), and the dimensions given as process information, that is, medium (W), thickness t ), and the length I7), the following formula is used to calculate an appropriate value for the difference in roll pushing amount on the working side and drive side of the hot flattening machine, etc.).

Here, 1 is an appropriate value for the difference in roll pushing amount between the working side and the driving side of the hot flattening machine (5), and α is a constant, which is obtained by performing, for example, multiple regression on the results of an experiment. FIG. 2 is an explanatory diagram of the roll pushing amount of the hot flattening machine. In the figure, the thick steel plate (1), upper roll (51), and lower roll (52X53) on the working side are shown by solid lines, and the thick steel plate (1), soil roll (51), and lower roll on the drive side are shown by solid lines. ) is shown by a broken line.

The amount of roll push on the working side refers to χ in the figure, and the amount of roll push on the drive side refers to χ in the figure. Therefore, the hot flat straightening machine (5
) is defined by 1χ□-χ,1.

The horizontal bending that offsets the horizontal bending (C) of the thick steel plate (1) is performed by controlling the roll control push amount θD of the hot flattening machine 0 so that the value of Iχ, - 1 becomes the value of (■) above. This is applied to the thick steel plate (1) to reduce the lateral bending (C) of the thick steel plate 0).

Example The amount of lateral bending and temperature of the hot-rolled thick steel plates shown in Table 1 before correction were measured based on the method of the present invention, the yield stress (σt) was estimated, and the work side of the hot-flattening machine and the Table 2 shows the specifications when the appropriate value (1) of the roll pushing amount on the drive side is calculated and the lateral bending is corrected based on the calculated value. In addition, when the horizontal bending of a large number of thick steel plates is corrected using the method of the present invention similar to the above, the horizontal bending per meter of the thick steel plate before and after the horizontal bending correction (see below)
) is shown in Figure 3. In the figure, the horizontal axis shows the horizontal bending before correction, and the vertical axis shows the horizontal bending after the horizontal bending correction by the method of the present invention.

Table 1 Table 2 Table 2 shows the horizontal bending (C) of the heavy steel plates in Table 1 whose horizontal bending (C) before correction was 5.25 mm/m by the horizontal bending correction method according to the present invention. ) was revised to 1.2 fins, and the maximum decrease in thickness before and after rolling was 0.01ffi11.
It can be seen that the following can be done. In addition, as shown in Fig. 3, the horizontal bending before correction (C
) is ±5■ The horizontal bending (C) of a thick steel plate with an irises of ±0,15
It can be seen that it can be modified to m++. In this case as well, the maximum reduction in thickness was set to 0.011111.

Effects of the Invention As described above, the method of the present invention corrects the horizontal bending of the metal plate by adjusting the difference in roll pushing amount on the working side and drive side of the hot flattening machine to an appropriate value, so that the thickness of the metal plate can be reduced. It is possible to reduce the lateral bending to a practically acceptable amount without impairing the accuracy. Further, a remarkable effect is obtained in that lateral bending that occurs after rolling can also be corrected.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the amount of roll indentation in the method of correcting horizontal bending of a metal plate according to the present invention, and Fig. 3 shows the horizontal bending of a thick steel plate with a length of 1 m before and after correcting the horizontal bending by the method of the present invention. FIG. 4 is an example of equipment for manufacturing thick steel plates, and FIG. 5 is an explanatory diagram of horizontal bending. 1...Thick steel plate 2...Heating furnace 3...
Conveyance table 41... Rough rolling mill 41... Finishing rolling mill 5... Hot flattening machine 51...
Upper roll 52...Lower roll 53...Lower roll 6...Cooling bed 71...Dimensions
72...Material 8...Camera
81... Image storage 82... Image processing
83... Lateral bending measurement 9... Thermometer 9
1... Temperature measurement 92... Yield stress estimation lO
...Appropriate value calculation 11...Roll push amount control χ1
... Roll pushing amount χ, ... Roll pushing amount C.
...Horizontal bending amount Homare 2 Figure 30 Procedural amendment written form) Director General of the Patent Office Michibe Uga 1, Indication of the case Patent Application No. 38000 of 1985 2, Title of invention Method for correcting lateral bending of metal plate 3 , Relationship with the person making the amendment Patent applicant address 5-15 Kitahama, Higashi-ku, Osaka Name (21
1) Sumitomo Metal Industries Co., Ltd. Representative Norifumi Kumagai 4, Agent March 31, 1986 66 "Brief explanation of drawings" column 7 of the specification subject to amendment, Contents of the amendment (1) of the specification From the last line of page 8, ``Figure 1 is'' to the line 1 of page 9, ``Explanatory diagram,'' are changed to ``Figure 1 is a system diagram of the horizontal bending correction method of a metal plate of the present invention, and Figure 2 is a thermal An explanatory diagram of the roll push amount of the flattening machine, corrected to ``.

Claims (1)

[Claims] Measuring the lateral bending and temperature of hot rolled metal plates,
From each of the above measured values and the dimensions and material of the metal plate, calculate the appropriate value for the difference in the amount of roll pushing on the working side and drive side of the hot flattening machine, and then use the hot flattening machine to flatten the metal based on the appropriate value. How to correct horizontal bending of a board.