JPH02307601A - Rolling mill - Google Patents

Abstract

PURPOSE:To effectively correct a quarter elongation and composite edge and web elongation by shifting a roll pair imparted with the waveform roll crown which can be approximated by the two pitches of a sine curve in the axial direction of the rolls. CONSTITUTION:The rolls having the crown (W crown) which can be approximated by the two pitches of the sine curve are disposed as 1st intermediate rolls 3. A stainless steel sheet is rolled by shifting the 1st intermediate rolls W in the axial direction and making combination use of the extrusion with divided back up rolls. The excellent ability to correct the quarter elongation and the composite edge and web elongation is obtd. in this way and the flatness control is executed over a wide range.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a rolling mill having an excellent flatness control function.

(Prior Art) There are strict requirements for the shape quality of rolled plate products, and therefore it is desired that the plate thickness accuracy during rolling be high. Regarding plate thickness accuracy in the longitudinal direction, the required accuracy is ensured by performing automatic plate thickness control (AGC) in the hot or cold rolling process.

On the other hand, thickness accuracy in the width direction is essential for shape control of rolled plate products. It is important to avoid shape defects such as compound elongation caused by mixed elongation.

However, no technology has been established that can satisfy the requirements for sheet thickness accuracy in the width direction, and various rolling methods and rolling machines have been proposed.

One such method is to control the shape of the rolled material by dividing the outermost backup roll into a plurality of parts in the axial direction and adjusting the amount of displacement of each divided roll. However, the effectiveness of this method is diminished the more intermediate rolls are present between the backup roll and the work roll. Used for inter-rolling, 12
In particular, multi-high rolling mills equipped with many intermediate rolls, such as stages and 20 stages, have not been able to fully demonstrate their capabilities.

To improve this point, the
A method of using a work roll bender or an intermediate roll bender in combination with the above-mentioned backup roll displacement adjustment method was proposed in the above publication. However, this method has the disadvantage that the equipment becomes complicated, and as the roll becomes thinner or the roll barrel becomes longer, the pending force does not work all the way to the center, so the control force remains only at the ends of the rolled material. there were.

Further, Japanese Patent Publication No. 63-207405 and the like proposes a method in which one end of the intermediate roll is tapered and each of the intermediate rolls is shifted independently in the axial direction. However, even in this method, the range in which the control force is applied is only around a part of the taper, and furthermore, it is complicated in that the taper shape must be changed one by one depending on the steel type, plate width, etc.

Further, in Japanese Patent Publication No. 63-30104, etc., a vertically arranged rolling mill is proposed in which the rolls are provided with an S crown that can be approximated by a cubic equation and are shiftable in the axial direction.

However, even with this method, only the ends and center of the rolled material could be controlled, and it was powerless to control quarter elongation, as well as compound elongation in which belly elongation, edge elongation, etc. were mixed.

(Problems to be Solved by the Invention) This invention overcomes the above problems and proposes a rolling mill that has excellent shape control ability and can correct complex shape defects such as quarter elongation and compound elongation. The purpose is to

(Means for Solving the Problems) That is, the present invention provides a rolling mill in which a backup roll is arranged behind a pair of work rolls, in which at least one roll selected from a group of rolls consisting of the work rolls and the backup rolls is provided. A set of two rolls is provided with a roll crown extending over at least two wavelengths of a waveform curve consisting of the same sinusoidal curve, and each pair of crowned rolls is arranged such that the roll axis directions are opposite to each other. ,
A rolling mill characterized in that the rolling mill is movable in the roll axis direction and is incorporated in a mill housing, or a rolling mill in which an intermediate roll and a backup roll are sequentially arranged behind a pair of work rolls, the work rolls being movable in the roll axis direction. , a set of at least two rolls selected from a roll group consisting of an intermediate roll and a backup roll,
A roll crown extending over at least two wavelengths of a waveform curve made of the same sinusoidal curve is provided, and each pair of crown-applying rolls is arranged so that the roll axis directions are opposite to each other, and This rolling mill is characterized in that it is movably incorporated into a mill housing.

Further, the present invention is a rolling mill in which a roll bending device is incorporated in the above-mentioned rolling mill.

Hereinafter, this invention will be specifically explained based on the drawings.

FIGS. 1(a) and 1(b) show the roll arrangement of a 20-high rolling mill, as an example according to the invention, in side view and front view.

In the figure, ■ is a rolled material, 2 is a work roll, 3 is a first intermediate roll, 4 is a second intermediate roll, and 5 is a split type backup roll. Work rolls 2 are arranged, and these work rolls 2
A total of 4 first intermediate rolls, 2 trees each, behind 3
However, behind the first intermediate roll 3, there is a second intermediate roll 4 of 6 trees in total, 3 trees each on the upper and lower sides, and a second intermediate roll 4 with
A total of eight split-type backup rolls 5, each with four rolls on each side, are installed behind the rolls, and these rolls constitute a 20-high rolling mill.

In addition, 6 is a roll steering device.

Among these, the second intermediate roll 4 shown with diagonal lines in FIG.
A roll crown consisting of a waveform curve that can be approximated by two pitches of a sine curve is provided, and the structure is such that it can be shifted in the axial direction of the roll.

Here, the rolls to which a waveform curve that can be approximated by 2 pitches of a sine curve is not limited to the above example, but can be freely selected from among the work roll 2, the first intermediate roll 3, and the second intermediate roll 4. You can choose to match it with silk.

Further, the roll shift device may be either hydraulic or electric.

(Function) As shown in Fig. 2 (a) to (C), a pair of rolls each having a corrugated roll crown with a sinusoidal curve of 2,000 minutes is installed in opposite directions in the roll axis direction. The roll gap change in the case of shift I is shown.

FIG. 5A shows a case where the pair of rolls are arranged opposite each other and the roll gap is constant in the axial direction. Figure (b) is (
This is a case where each roll is moved in the direction of the arrow from the state in a), but the quarters are partially narrow (and the roll gears are wide at the center and ends.
C) is a case in which each roll is moved in the opposite direction to that shown in FIG. 3B, and the roll gap is wide in a part of the quarter and narrow in the center and ends.

Therefore, by appropriately shifting a pair of rolls provided with such a wave-shaped roll crown that can be approximated by two pitches of a sine curve in the roll axis direction, it becomes possible to effectively correct quarter elongation and ear-belly compound elongation. .

Figure 3 shows the first intermediate roll (11MR) or second intermediate roll (2TMR) of the 20-high rolling mill shown in Figure 1 above.
Using a roll pair with a wave-shaped roll crown (hereinafter simply referred to as W crown) that can be approximated by two pitches of a sine curve, we investigated the shape control ability when appropriately shifted in the roll axis direction. Similarly, when the waveform roll crown (hereinafter simply referred to as S crown) that can be approximated by a sine curve of 1,000ths of a pitch is shifted from a pair of rolls with (i'4), the result is a so-called one-side taper that is tapered and ground on one side. A comparison is shown between a case where the roll is shifted and a case where a split backup roll is pushed out.

The shape control ability was evaluated by the difference in elongation Δ2 between the center and the ends of the rolled material and the difference in elongation Δ4 between the center and a part of the quarter.

As is clear from the figure, in the case of single taper roll shift and S-crown shift, although it is possible to control ear elongation and belly elongation to a certain degree, little can be expected about quarter elongation and ear belly compound elongation control. .

Note that split backup roll extrusion can only be expected to provide slight control over quarter elongation and ear-belly compound elongation.

On the other hand, in the case of W crown shift, a remarkable effect can be expected in terms of quarter elongation and ear-belly compound elongation control.

In this invention, the pair of rolls to which the W crown is applied may be any pair of rolls as long as it is a pair of at least two rolls selected from a group of rolls consisting of a work roll, an intermediate roll, and a backup roll. However, it is more preferable that each roll pair is selected from a group of homogeneous rolls, namely a work roll pair, an intermediate roll group, and a backup roll group. Furthermore, the control effect increases as the W crown imparting roll is closer to the material to be rolled, and the arrangement of each roll pair increases in the order of point symmetry, vertical symmetry, and horizontal symmetry with the material to be rolled as the center.

In addition, the reason why the backup roll in a 12-high or 20-high multi-high rolling mill is made into a split type is to achieve shape control through extrusion of the hack-up roll, so a split-type backup roll is indispensable in a conventional multi-high rolling mill. there were. However, as described above, by applying the present invention, it is possible to particularly control quarter elongation and ear-belly compound elongation, so there is no need to use a split type backup roll, and an integrated type backup roll can be used.

Therefore, it is possible to fully expect the original function of the backup roll to provide a high-pressure lower edge, and there is no transfer of roll marks to the rolled material due to scum adhesion, and it is also possible to omit the eccentric mechanism that is essential for split-type backup rolls. becomes. Furthermore, it is advantageous to provide a W crown to the integrated backup roll because the shape control range can be further expanded.

It is also possible to use a higher-order function as the waveform curve to be applied to the roll, but compared to the case where a wavy roll crown is applied using a sine curve, when following a sine curve, the roll can be created simply by giving the amplitude and period. The crown amount and waveform pitch can be set, so a wide shape control range can be easily achieved. On the other hand, if it follows a higher order function,
Setting the roll crane amount and waveform pitch is complicated and difficult. For example, as shown in Figure 4, when the center of the roll barrel is set as the coordinate origin and a waveform curve is given that is symmetrical with respect to this origin, the higher-order function is expressed by the following equation (1).
It can be shown as follows.

f(x) = a+x+a3x'+a5x5+----
-+an
2) Coefficients a1 to a7 so as to satisfy -1 to 6, respectively.
need to be determined.

Table 1 Especially when n=5, that is, when expressed by a fifth-order odd function as in equation (1)', the unknown quantity is al+83+a
5, therefore only three conditional expressions can be considered in the expression (2) shown in Table 1.

f(x) = a, x+a3x3+a5x5...(1
)'° For example, considering equation (2)-L (2)-2 shown in Table 1 to define the crown amount, the conditions for defining the pitch are four conditional equations (2)-3, (2) )-4
, (2)-5, and (2)-6. Therefore, the pitch of the crown cannot be arbitrarily changed.

As described above, it was found that by applying a sinusoidal curve, an arbitrary crown can be easily obtained and the subsequent control is also easy. This is achieved by using the assigned role.

(Example) Implementation M± In the 20-high rolling mill shown in FIG.
), the first intermediate roll is a crown (W crown) that can be approximated by two pitches of the sine curve shown in Figure 6.
A stainless steel plate with a width of 1000 mm is made into a stainless steel plate with a thickness of 1.0 mm by shifting this first intermediate roll in the axial direction and also using split backup roll extrusion.
It was rolled from 2 mm to 1.0 mm.

The shape control ability at this time is shown in FIG. 5(b).

Furthermore, Fig. 5(b) shows a case where a roll having a single tapered shape as shown in Fig. 7 is similarly used as the first intermediate roll (conventional device A), and the single tapered roll is shifted in the axial direction. Also shown are the results of an investigation into the shape control ability when similar rolling is performed using split hack-up roll extrusion.

As is clear from FIG. 5(b), the shape control ability of the conventional device to follow compound elongation and quarter elongation is extremely small.

On the other hand, when using the device of this invention, it is possible to obtain a wide control range that can sufficiently handle compound elongation and quarter elongation, and moreover, it is possible to change the shape of the intermediate roll for various types of rolled materials. It was possible to obtain a plate with a good shape without any problems.

In the same 20-high rolling mill as Kairi Masumata, a roll having a crown (W crown) that can be approximated by two pitches of a sinusoidal curve as shown in Fig. 6 is used as the second intermediate roll as shown in No. 81m (a). The results of an investigation regarding the shape control ability when rolling was performed in the same manner as in Example 1 are shown in FIG. Further, a similar investigation was conducted in the case where the same roll as in the conventional device A in Example 1 was applied as the second intermediate roll. Note that rolling was performed by adding a roll bending device to both side rolling mills.

As is clear from FIG. 8 (+), when two sets of W crown rolls are used, the controllability range of quarter elongation and composite elongation can be further expanded.

Balance M↓ In the same 20-high rolling mill, the 6th roll is used as a work roll.
The crown (
FIG. 9(b) shows the results of an investigation regarding the shape control ability when rolling was performed in the same manner as in Example 1 using rolls having a W crown) arranged as shown in FIG. 9(a). In addition, a similar investigation was conducted in the case where the same roll as in the conventional device A in Example 1 was applied to the work roll.

As is clear from FIG. 9 (+), even when the work roll is provided with a crown approximated by a sine curve, excellent quarter elongation and composite elongation control ability can be obtained as in Example 2. There is.

In fact, in a 20-high rolling mill equipped with an integral backup roll shown in Figures 10 (a) and (b), the hack-up roll has a crown that can be approximated by two pitches of the sinusoidal curve shown in Figure 6. FIG. 10(c) shows the results of an investigation on the shape control ability when rolls having a (W crown) were arranged as shown in FIG. 10(a) and rolling was performed in the same manner as in Example 1.

As is clear from FIG. 10(C), even when the double crown roll is applied to the integrated hack-and-roll, the ability to control quarter elongation and compound elongation can be ensured as in the above embodiment.

In a 20-high rolling mill, rolls with a crown (W crown) that can be approximated by a sine curve of 2 pitches as shown in Figure 6 are used as two sets of rolls above and below the first intermediate roll and The results of investigating the shape control ability when rolling was performed in the same manner as in Example 1 using two sets of upper and lower rolls located outside the two intermediate rolls as shown in FIG. 11(a) were as follows: - As shown in Figure (b).

As is clear from FIG. 11(b), when two sets of W crown rolls are used, the range of controllability of quarter elongation and composite elongation can be further significantly expanded.

In the 12-high rolling mill shown in Fig. 12(a),
), the intermediate roll was provided with a crown (W crown) that could be approximated by two pitches of the sine curve shown in Figure 6, and the shape control ability was investigated when rolling was performed in the same manner as in Example 1. The results are shown in the same figure (b). In addition, a similar investigation was conducted in the case where a roll similar to that of the conventional device A in Example 1 was applied as an intermediate roll.

As is clear from Fig. 12(b), W was applied to the 12-high rolling mill.
Even when a crown roll is applied, the ability to control quarter elongation and compound elongation can be ensured.

In the same 12-high rolling mill as shown in Figure 13(a), a crown (W crown) that can be approximated by two pitches of the sine curve shown in Figure 6 is applied to the intermediate roll and work roll. The results of investigating the shape control ability when rolling was carried out in the same manner as in Example 1 are shown in Figure (b).
Shown below.

As is clear from Fig. 13(b), W was applied to the 12-high rolling mill.
Even when a crown roll is applied, the ability to control quarter elongation and compound elongation can be ensured.

In the six-high rolling mill shown in Fig. 14(a), as shown in Fig. 14(a),
As shown in FIG. 6, a point-symmetric roll of the backup roll was given a W crown at two pitches of the sinusoidal curve shown in FIG. 6, and rolling was carried out in the same manner as in Example 1. The results of an investigation regarding the shape control ability when the test was performed are shown in FIG. 2(b). In addition, a similar investigation was conducted in the case where a roll similar to that of the conventional device A in Example 1 was applied as a backup roll.

As is clear from Fig. 14(b), W was applied to the 12-high rolling mill.
Even when a crown roll is applied, the ability to control quarter elongation and compound elongation can be ensured.

In the same 6-high rolling mill, as shown in Fig. 15 (a), all backup rolls were given crowns (W crowns) that could be approximated by two pitches of the sine curve shown in Fig. 6. The result of investigating the shape control ability when rolling was performed in the same manner as in Example 1 is shown in FIG. 2(b).

As is clear from Fig. 15(b), W was applied to the 12-high rolling mill.
Even when a crown roll is applied, the ability to control quarter elongation and compound elongation can be ensured.

In a vertical type 6-high rolling mill as shown in Fig. 16(a) for five-pronged rolling mill, as shown in Fig. 16(a), the intermediate roll pair is approximated by two pitches of the sine curve shown in Fig. 6. The result of investigating the shape control ability when rolling was performed in the same manner as in Example 1 with a crown (W crown) that can be formed is shown in the same figure.

Furthermore, when the same rolls as in the conventional device A in Example 1 are applied to the intermediate roll pair, and when the 3 rolls shown in FIG.
Also when a roll with a crown (S crown) approximated by the following formula is applied to a pair of rolls between the middle and the middle (conventional device opening),
A similar investigation was conducted.

As is clear from FIG. 16(b), even when a W crown roll is applied to a six-high rolling mill, the ability to control quarter elongation and compound elongation can be ensured.

Disaster Flame U In the same vertical 6-high rolling mill, as shown in Fig. 18 (a), a crown (W crown) that can be approximated by two pitches of the sine curve shown in Fig. 6 is given to the backup roll pair. However, the result of investigating the ability to control the shape of the cup after rolling in the same manner as in Example 1 is shown in FIG. 2(b).

As is clear from FIG. 18(b), even when a W crown roll is applied to a six-high rolling mill, the ability to control quarter elongation and compound elongation can be ensured.

In a four-high rolling mill as shown in Figure 19(a), the work roll pair has a crown that can be approximated by two pitches of a sine curve as shown in Figure 6. (B) shows the results of an investigation on the shape control ability when rolling (W crown) was applied and the same rolling i 0- as in Example 1 was performed. In addition, a similar investigation was conducted in the case where the same rolls as in the conventional device A in Example 1 were applied to the intermediate roll pair.

As is clear from FIG. 19(b), even when a W crown roll is applied to a four-high rolling mill, the ability to control quarter elongation and compound elongation can be ensured.

Example U In the same four-high rolling mill, as shown in FIG. 20(a), a crown (W crown) that can be approximated by two pitches of the sine curve shown in FIG. 6 was given to the buffer and tube roll pair, and The results of an investigation regarding the shape control ability when rolling was performed in the same manner as in Example 1 are shown in FIG. 2(b).

As is clear from FIG. 20(b), even when a W crown roll is applied to a four-high rolling mill, the ability to control quarter elongation and compound elongation can be ensured.

(Effects of the Invention) Thus, according to the rolling mill according to the present invention, it is possible to obtain an excellent correction ability particularly for quarter elongation and selvage compound elongation, and therefore it is possible to realize flatness control over a wide range.

[Brief explanation of drawings]

FIGS. 1(a) and (b) are a side view and a front view, respectively, showing the roll arrangement of a 20-high rolling mill to which the present invention is applied, and FIGS. 2(a) to (C) are respectively showing a W crown roll. Figure 3 shows the changes in the roll gap when the rolls are installed parallel to each other in opposite directions and shifted in the axial direction. Figure 4 shows the shape control ability when each roll pair is applied individually. Figure 4 is an explanatory diagram of a W crown that can be approximated by a higher-order formula. Figures 5 (a) and (b) are each A roll arrangement diagram and a shape control range diagram showing the arrangement of W crown rolls in a corrugated rolling mill. Fig. 6 is a diagram showing a suitable W crown that can be approximated by two pinches of a sinusoidal curve. Fig. 7 is a single tapered roll. Figures 8 and 9 (a) and (b) are roll arrangement diagrams and shape control range diagrams showing the arrangement of W crown rolls in a 20-high rolling mill, respectively. Figure 10 (a) , (b) are side and front views showing the roll arrangement of the 20-high rolling mill, respectively, (C) is a shape control range diagram, and Figures 11 (a) and (b) are the 20-high rolling mill, respectively. The roll arrangement diagram and shape control range diagram showing the arrangement of the W crown roll in Figures 12 and 13 (a) and (b) are respectively 12
14 and 15 (a) and (b) are roll arrangement diagrams showing the arrangement of W crown rolls in a 6-high rolling mill and shape control range diagrams, respectively. and a shape control range diagram; Figures 16 and 18 (a) and (b) are a roll arrangement diagram and a shape control range diagram showing the arrangement of W crown rolls in a vertical 6-high rolling mill, respectively; Figure 17 is a shape control range diagram; Figures 19 and 20 (a) and (b) are a diagram showing the S crown that can be approximated by a cubic equation, and a roll arrangement diagram showing the arrangement of the W crown roll in a four-high rolling mill, respectively, and a shape control range diagram. , is. 1...Rolling fFA2...Work roll 3...First
Intermediate roll 4...Second intermediate roll 5...Huck-up roll 6...Roll-hendinking device Fig. 1 (av Fig. 2 (a) (b) (C) Engraving of drawing (no change in content) ) Engraving of drawings (no change in content) Engraving of drawings (no change in content) 0 0.5 /, 0
Roll A-1, roll end h゛5゛, unblown base S pin Fig. 7 EH-θ, l EH-θ, engraving of drawing of EL engineering 300 drawer (no change in content) A2,. 1 to -3 Engraving of the drawings in Figure 9 (no changes to the content) Engraving of the drawings in Figure 9 and 10 (no changes to the content) Figure 10(b) Engraving of the drawings (no changes to the content) A2 11. , +-3 Figure 12: Engraving of drawings (no change in content) Figure 12: Figure 14 (a) Engraving of drawings (no change in content): A2 x to-3.1; Figure 15 (a). Engraving of the drawing (no change in content) Fig. 15 Fig. 16 (a) Engraving of drawing (no change in content) R extension R-'-+ Engraving of drawing (no change in content) Unblown 7L seat J Sheet Figure 18 (a) Engraving of the drawing (no change in content) 1□ No. 2-307601 (17) Figure 19 (a) Engraving of the drawing (no change in content) Figure 20 (a) Engraving of the drawing Engraving (no change in content...+-3 Procedural amendment (method) September 4, 1989, Commissioner of the Japan Patent Office Yoshi 1) Moon Yi 1, Indication of the case 1999 Patent Application No. 128873 2 , Name of the invention Rolling mill 3, Relationship with the case of the person making the amendment Patent applicant (125) Kawasaki Steel Corporation 4, Agent

Claims (1)

[Claims] 1. A rolling mill in which a backup roll is arranged behind a pair of work rolls, wherein at least two rolls selected from a roll group consisting of the work rolls and the backup roll are , imparting a roll crown extending over at least two wavelengths of waveform curves each consisting of the same sine curve, and for each of the above-mentioned crowning roll pairs,
A rolling mill characterized in that the axial directions of the rolls are arranged in opposite directions, and that the rolling mill is installed in a mill housing so as to be movable in the axial direction of the rolls. 2. A rolling mill in which an intermediate roll and a backup roll are sequentially arranged behind a pair of work rolls, each set of at least two rolls selected from a group consisting of the work roll, the intermediate roll, and the backup roll. A roll crown extending over at least two wavelengths of a waveform curve formed of the same sinusoidal curve is applied to the rolls, and for each pair of the above-mentioned crowned rolls,
A rolling mill characterized in that the axial directions of the rolls are arranged in opposite directions, and that the rolling mill is installed in a mill housing so as to be movable in the axial direction of the rolls. 3. The rolling mill according to claim 1 or 2, comprising a roll bending device.