JP2010269340A - Method of controlling meandering in reversing rolling mill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely eliminate the meandering of a rolling stock in a reversing rolling mill. <P>SOLUTION: A method of controlling the meandering of a rolling stock is provided for controlling the amount of meandering of the rolling stock during rolling on the basis of the amount of camber of the rolling stock which is not yet rolled. In the method, in particular the relationship between the amount of the camber of the rolling stock and the amount of the meandering which is generated when rolling the rolling stock is preobtained and also the amount of the generated meandering and the amount of leveling of a rolling mill for compensating the amount of the generated meandering is preobtained, and the amount of the leveling of the rolling mill is adjusted in accordance with the amount of the camber of the rolling stock. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a meander control method for compensating (eliminating or reducing) meandering of a rolled material that occurs when the rolled material is reverse-rolled.

In the rolling process of the plate material, the meandering phenomenon in which the traveling direction of the plate material coming out of the rolling machine is shifted in the horizontal direction causes a plate passing trouble, making it impossible to continue rolling, and dividing the plate material to increase the rolling length. This is a major cause of lowering the rolling yield, such as forced rolling.
Many techniques are known as techniques for suppressing such meandering phenomenon of rolled material.
For example, in Patent Document 1, the tension measurement means provided on the exit side of the tandem rolling mill detects the work side tension and the drive side tension of the plate material, calculates the tension difference, and the tension difference deviates from a predetermined range. In this case, leveling control is performed so as to be within a predetermined range, and the meandering amount is within the predetermined range using a plate material position detector for detecting the meandering amount and a meander correcting roll provided on the entry side of the tandem rolling mill. A meandering control method for controlling a meandering correction roll is disclosed.

  Further, in Patent Document 2, the working side tension and the driving side tension excluding the plate width end edge are measured in the sheet material on the rolling mill entrance side, and the rolling of the sheet material is performed from the tension difference between the working side tension and the driving side tension. It is disclosed that the meandering amount on the machine entrance side is obtained, and the leveling amount is adjusted during threading or before the start of the next pass based on the meandering amount on the entrance side of the rolling mill.

JP 2004-243376 A JP 2007-229964 A

Patent Literature 1 and Patent Literature 2 measure the working side tension and driving side tension of the rolled material, determine the meandering amount from the obtained tension, and adjust the leveling amount based on the obtained meandering amount. Feedback control based on the amount of meandering is performed.
However, although these techniques can suppress the meandering to some extent, it is possible to ensure an inconvenient situation in which large meandering occurs at the beginning of rolling or the amount of meandering that occurs at the beginning of rolling increases at the end of rolling. It was not possible to suppress it.
In view of the above problems, an object of the present invention is to provide a meandering control method that can reliably eliminate meandering of a rolled material in a reverse rolling mill.

In order to achieve the above object, the present invention takes the following technical means.
That is, the meandering control method according to the present invention is a meandering control method in a reverse rolling mill for rolling a rolled material in forward and reverse directions, and based on the camber amount of the rolled material before rolling, The amount of meandering is controlled.
As a result of intensive studies on the cause of meandering of the rolled material, the inventors of the present application are sure that the difference between the working side tension and the driving side tension of the rolling mill is caused by meandering. It came to know that the camber (bending along the longitudinal direction of a rolling material) which exists in the rolling material before rolling has influenced the meandering at the time of rolling.

In FIG. 2, the horizontal axis indicates the length of the rolled material, and the vertical axis indicates the meandering amount and the camber amount, and “the camber amount of the rolled material before rolling” and “the rolled material is rolled during reverse rolling. It shows the relationship with the “meandering amount at the time”.
The camber amount is an output value of CPC (Center Position Control) that detects meandering installed in the previous process (annealing process). As is apparent from this figure, when the rolled material having a camber is rolled, the meandering of the rolled material starts from the first pass. In addition, since the amount of meandering in the final pass is larger than the amount of meandering in the first pass (FIG. 2 (a) → FIG. 2 (b)), meandering once generated may increase with repeated rolling. Recognize. It can also be seen that the curve representing the camber amount and the curve representing the meandering amount are similar in shape. Conversely, it was also clarified that meandering during rolling hardly occurs when the amount of camber in the rolled material before rolling is small.

Based on these facts, the knowledge that the meandering of the rolled material during reverse rolling can be suppressed as much as possible by controlling the meandering amount of the rolled material during rolling based on the camber amount of the rolled material before rolling. It came to.
Preferably, the relationship between the camber amount of the rolled material and the meandering amount generated when the rolled material is rolled is obtained in advance, and the generated meandering amount and the leveling amount of the rolling mill that compensates for the meandering amount are determined. When the first pass rolling is obtained, the leveling amount of the rolling mill may be adjusted according to the camber amount of the rolled material.

By doing so, it is possible to reliably compensate (reduce or eliminate) the meandering of the rolled material in the reverse rolling mill.
Further, the relationship between the meandering amount of the rolled material and the leveling amount of the rolling mill that compensates the meandering amount is obtained in advance, and when performing the second and subsequent passes, the leveling amount obtained from the meandering amount is determined by the rolling. It is good to apply to the machine.
It is good to perform the meandering control method in the rolling mill mentioned above with respect to the front-end | tip part and / or tail end part of a rolling material.

  By using the meandering control method in the reverse rolling mill according to the present invention, meandering of the rolled material can be reliably eliminated.

It is the schematic of a reverse rolling mill. It is the figure which showed the relationship between the camber amount and meandering amount in a rolling material longitudinal direction. It is the figure which showed the generation | occurrence | production state of meandering, (a) is the figure which looked at the rolling mill from the rolling material advancing direction, (b) is the figure which planarly viewed the rolling mill. It is a figure for demonstrating the meandering control method which concerns on this invention. It is a flowchart for demonstrating the meandering control method which concerns on this invention. It is the figure which showed the relationship between the amount of meandering, and the camber amount. It is the figure which showed the relationship between the amount of meandering and the amount of leveling. (A) is the figure which showed the relationship between the amount of meandering and a reduction plate thickness difference, (b) is the figure which showed the relationship between a leveling amount and a reduction plate thickness difference. It is a figure which shows the Example which rolled using the meandering control method which concerns on this invention.

Hereinafter, a meandering control method in a reverse rolling mill according to the present invention will be described with reference to the drawings, illustrating cold reverse rolling of a thin plate of steel, stainless steel, titanium or the like.
FIG. 1 shows an example of a reverse rolling mill.
The reverse rolling mill 1 (sometimes simply referred to as the rolling mill 1) is a multi-stage rolling mill, and in the case of this embodiment, a pair of upper and lower work rolls 2 and 2 and a pair or multiple pairs of backup rolls 3 and 3 It has. A winding reel 4 is provided on the entry side and the exit side of the reverse rolling mill 1.
The winding reel 4 on the entry side is an unwinding reel 5 that supplies the rolled material W to the reverse rolling mill 1, and the winding reel 4 on the delivery side of the rolling mill 1 is a winding that winds the rolled material W after rolling. It is reel 6. Since the main rolling mill 1 is the reverse rolling mill 1, in the next rolling, the take-up reel 6 becomes the take-up reel 5 and the take-up reel 5 becomes the take-up reel 6.

Further, the reverse rolling mill 1 is provided with a leveling control unit 7 that makes the leveling amount (difference between the work-side gap amount and the drive-side gap amount) in the work rolls 2 and 2 variable. The leveling control unit 7 includes a process computer that controls the reverse rolling mill 1.
As shown in FIG. 3, various causes of the meandering of the rolled material W generated during rolling are conceivable. One of them is the left and right sides of the work rolls 2 and 2 (working side WS and driving side DS). The difference in the gap amount, that is, the leveling amount is not appropriate. For example, as shown in FIG. 3A, when the leveling amount is not appropriate with respect to the wedge of the rolled material W and the end of the rolled material on the work side is greatly reduced, the longitudinal direction of the rolled material W is increased. The material stretches, and as a result, meandering to the working side as shown in FIG. 3B occurs.

Hereinafter, meandering control (leveling control) of the present invention performed in the leveling control unit 7 will be described.
As shown in FIGS. 4 and 5, first, before the first pass rolling is performed, the “camber amount of the rolled material W” in the pre-reverse rolling process is input to the leveling control unit 7. When the rolled material W is a titanium material or the like, a pickling process or an annealing process is performed as a pre-process of rolling. The amount of camber in the previous process is estimated by CPC or the like provided in the apparatus that performs the previous process.
Thereafter, as shown in FIG. 6, using the “relation between the meandering amount of the rolled material W and the camber amount” obtained in advance, the meandering amount that would occur in the first pass is determined from the camber amount of the material before rolling. Predict. Since the camber amount and the first-pass incoming meander amount are equal, the horizontal axis in FIG. 6 employs the first-pass incoming meander amount (CPC voltage value) measured by CPC. Yes. As a result, it was found that the camber amount (input-side meandering amount) = 18 × CPC voltage value. (S101)
Next, in order to compensate for the predicted meandering amount (zero or to decrease), a “relationship between the meandering amount of the rolled material W and the leveling amount necessary for compensating it” (FIG. 7). The leveling amount is changed with respect to the reverse rolling mill 1 based on the reference). Specifically, the leveling amount of about 3/1000 of the meandering amount is added to the gap amount of the work rolls 2 and 2 on the side where the rolled material W meanders (swells), so that the space between the work rolls 2 and 2 is widened. To do. Then, the rolling material W corresponding to the portion where the roll gap is widened is reduced in the degree of rolling in the plate thickness direction, and consequently the material elongation in the longitudinal direction of the rolling material W is reduced, and the meandering is suppressed. It becomes. (S103)
After the feed-forward control of the leveling amount as described above, the first pass rolling is performed. (S104)
As shown in FIG. 4, after the second pass, the meandering amount of the rolled material W in the even pass is measured, and the leveling amount of the next odd pass is obtained from the obtained meandering amount. Applies to rolling mill 1

That is, the meandering amount is detected in the second pass (even number pass) (S105), and the corrected leveling amount is obtained using the data disclosed in FIG. 7 based on the obtained meandering amount (S106). Thereafter, the obtained leveling amount is applied to the rolling mill 1. That is, the leveling amount is added to the gap amount between the work rolls 2 and 2 on the side where the rolled material W meanders (swells) so that the space between the work rolls 2 and 2 is widened. Then, the rolling material W corresponding to the portion where the roll gap is widened is reduced in the degree of rolling in the plate thickness direction, and consequently the material elongation in the longitudinal direction of the rolling material W is reduced, and the meandering is suppressed. It becomes. (S107)
Thereafter, rolling in the third pass (odd pass) is performed (S108).

Rolling is performed in the same manner after the fourth pass. That is, the meandering amount at the time of rolling in the fourth pass (even number pass) is obtained, and the leveling amount in the fifth pass (odd number pass) is changed based on this.
The relationship between the measurement of the meandering amount and the correction of the leveling amount is not limited to the above. The amount of meandering during rolling of the odd-numbered pass may be obtained, and the leveling amount in the next even-numbered pass may be corrected based on the meandering amount. The meandering amount in the first pass to which the control by the camber amount is added may be reflected in the second pass. The level of the current pass is corrected based on the amount of meandering measured in the previous pass, not the “one jump” control, and the level of the next pass is measured based on the amount of meandering in the current pass. The amount may be corrected.

Thus, by performing feedback control such as changing the leveling amount in the next pass based on the amount of meandering in the current pass, the amount of meandering of the rolled material W during reverse rolling can be reliably suppressed.
In FIG. 6 described above, the horizontal axis represents the meandering amount, and the vertical axis represents the camber amount causing the meandering amount, and represents “the relationship between the meandering amount and the camber amount”. This graph was obtained by organizing and examining a number of rolling record data.
In FIG. 7 described above, the horizontal axis indicates the meandering amount, and the vertical axis indicates the correction leveling amount, which represents “the relationship between the meandering amount and the correction leveling amount”. FIG. 7 is also obtained by arranging a number of rolling record data. As can be seen from this figure, the relationship between the meandering amount and the leveling amount has a correlation irrespective of the steel type of the rolled material W, the rolling conditions, and the number of rolling operations (the number of passes). When a linear regression curve is obtained, y = −2.99853 + 50.498 (x: meandering amount, y: leveling amount). Therefore, if the leveling amount of about 3/1000 of the meandering amount is given to the rolling mill 1, the meandering amount can be compensated.

  Specifically, FIG. 7 shows a meandering deviation of the rolled material W by measuring the amount of meandering in the rolled material W in which meandering has occurred and dividing the difference between the left and right tensions obtained during rolling by the Young's modulus of the rolled material W. Asked. The left / right elongation deviation Δε is converted into a reduction plate thickness deviation (hd−hw) based on the relationship of the expression (1), and “a relationship between the meandering amount and the reduction plate thickness difference” as shown in FIG. Asked.

On the other hand, by performing an experiment to change the gap amount while the rolled material W is held in the rolling mill 1, the “relation between the leveling amount and the reduction plate thickness difference” as shown in FIG. 8B is obtained. It was.
The data of FIG. 7 can be obtained by combining FIG. 8A and FIG. 8B.

FIG. 9 shows the state of occurrence of the meandering amount before and after performing the meandering control of the present embodiment.
The rolled material W used in the experiment is a titanium material, the finishing width is 1000 mm, and the finishing length is 2000 m. This rolled material W was reverse-rolled 10 times at a sheeting speed of 300 mpm. The maximum value of the camber amount existing in the rolled material before rolling was 10 mm.
As shown in FIG. 9A, when the meandering amount control is not performed, the meandering amount of about 20 mm generated in the first pass becomes a large meandering amount of about 40 mm in the fifteenth pass, for example, every time rolling is repeated. . When such a large meandering occurs, there is a high possibility that troubles such as causing a plate passing trouble and making it impossible to continue rolling or forcing rolling with a limited rolling length will occur. .

However, as shown in FIG. 9B, in the rolling of this embodiment, the amount of meandering in the first pass is 10 mm or less, and the amount of meandering is about 10 mm even after repeated rolling, which is relatively good. It has become. If the meandering amount is 10 mm or less, good rolling can be performed without any trouble in passing the plate.
By the way, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

For example, since it is clear that the meandering of the rolled material W occurs particularly at the tip portion of the rolled material W, the above-described meandering control method may be adopted only for the leading end portion of the rolled material W. However, it may be applied to the tail end portion of the rolled material, and there is no problem even if it is applied to both the tip end portion and the tail end portion.
In the embodiment of the present invention, the reverse rolling has been described as an example. However, the application of the meandering control technology is not limited to the reverse rolling mill. The present invention can be applied to all rolling mills that perform sheet rolling in which the meandering of the rolled material is expected.

DESCRIPTION OF SYMBOLS 1 Reverse rolling machine 2 Work roll 3 Backup roll 4 Winding reel 5 Unwinding reel 6 Take-up reel 7 Leveling control part W Rolling material

Claims (4)

A meandering control method in a reverse rolling mill that rolls rolled material in forward and reverse directions,
A meandering control method in a reverse rolling mill, wherein the meandering amount of a rolled material during rolling is controlled based on a camber amount of the rolled material before rolling. The relationship between the camber amount of the rolled material and the meandering amount generated when the rolled material is rolled is obtained in advance, and the generated meandering amount and the leveling amount of the rolling mill that compensates for the meandering amount are obtained. ,
2. The meandering control method in the reverse rolling mill according to claim 1, wherein, when performing the first pass rolling, the leveling amount of the rolling mill is adjusted according to the camber amount of the rolled material. The relationship between the amount of meandering of the rolled material and the leveling amount of the rolling mill that compensates for the amount of meandering is determined in advance,
3. The meandering control method in the reverse rolling mill according to claim 2, wherein when performing rolling in the second pass and thereafter, a leveling amount obtained from the meandering amount is applied to the rolling mill.   The meandering control method in the reverse rolling mill characterized by performing the meandering control method in the rolling mill in any one of Claims 1-3 with respect to the front-end | tip part and / or tail end part of a rolling material.