JPS6336841B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an arrangement in which the width accuracy, cross-sectional profile, etc. of a steel strip are controlled to desired conditions at the time when the rolling process is completed in a hot rolling line or a cold rolling line. The present invention relates to a rolling method in which a three-point restraint type edger device is incorporated into a continuous rolling mill train.

During the rolling process of steel strip, it is unavoidable that edge drops (thin walled parts) occur at both ends in the strip width direction. As a method, side trimming is carried out using rotary round blade shearing, but in this side trimming, both edges of the steel strip are cut off over several millimeters to several tens of millimeters, so it usually takes 1 to 10 millimeters. There is a drawback that a yield loss of 2% is caused, and depending on the properties of the sheared surface, the product edge after cold rolling becomes saw-toothed, resulting in a reduction in quality.

As a means to deal with this drawback, a three-point restraint method has been developed that simultaneously corrects the width and thickness of the steel strip edge in both directions. In this three-point restraint control method, as shown in FIG. 1A, a steel strip a of uneven width with edge drops b at both ends is first
The width is corrected by vertical roll V as shown in FIG.
At this time, a slight bulge d is generated at the edge of the steel strip a due to rolling down, resulting in a so-called dog-bone shape, but at the same time, as shown in Fig. 1C, The steel strip is held down by the horizontal rolls H to prevent the strip from bending and swinging, and at the same time, the raised edges d are pressed toward the center to make the entire width uniform. In this method, the plate width is corrected and the plate thickness is corrected so that the plate width W corrected at the time of width reduction in Fig. 1B is not disturbed at the time of vertical reduction shown in Fig. 1C. The rolling down and rolling down are performed at the same position as shown in FIG.

As a concrete configuration of the three-point restraint type edger device, the device shown in FIG. 3 is provided symmetrically opposite the positions of both edge portions of the running steel strip a. Hereinafter, only one side will be explained. The three-point restraint type edger 1 includes a roll housing 10 that is integrally fixed to a sliding bed 11 so as to be movable in the width direction of the sheet. , 13 and one vertical roll 14. 3 rolls 1
2, 13, and 14 are provided in combination on the same line in the width direction of the plate at positions where they can be press-fitted and engaged with the steel strip a simultaneously from three directions, vertically and horizontally. The upper horizontal roll 12 is movable in the vertical direction by a fluid pressure cylinder 21, supported so as to be able to adjust the amount of rolling down, and the rotation of the drive motor 22 is transmitted through a universal joint. The lower horizontal roll 13 is an idle roll and has a bearing fixed to the roll housing 10, and the vertical roll 14 is also an idle roll.
Being made into a roll. A roll housing 10 incorporating these rolls is connected to a hydraulic cylinder 15.
is pressed in the direction of the edge of the steel strip a, causing the vertical rolls 14 to perform the desired reduction.

The three-point restraint type edger 1 constructed in this way is effectively used for removing edges and drops of steel strips and reducing plate crowns.However, in conventional rolling technology, this three-point restraint type edger Because it was incorporated before and after the rough rolling process of thick plate rolling, the pickling process, and before the cold rolling process, its effect on product accuracy in the finishing stage gradually diminished, and the metal Regarding flow, using external tension and cross-sectional stress of the steel strip,
This results in so-called indirect control, which has the disadvantage that sufficient control effects such as width accuracy cannot be expected.

SUMMARY OF THE INVENTION An object of the present invention is to address the drawbacks of the prior art in which a sufficient control effect could not be obtained despite incorporating a three-point restraint type edger device, and to By arranging it at the most effective position on the top, the control effect can be greatly improved.

Therefore, in the present invention, although the edging device itself has the same or very similar configuration as the conventional technology, the position of installation and usage form are unique, thereby achieving outstanding product improvement. The main focus is to obtain the value.

In the method of the present invention, as shown in FIGS. 4 to 6, a three-point restraint type edger device 1 is arranged in a continuous finishing mill row F, and at least the entrance side or exit side of the final stand F _o is provided. must be placed in the
They may be arranged on both the entry side and the exit side, and the number of arrangement may be one or more. In Figure 4, one etching device 1 is installed on the entrance side of the final stand F _o and its preceding stand F _o -1, and three more are installed on the exit side of the final stand F _o , for a total of five units. This is an example in which a Furthermore, Fig. 5 shows an embodiment in which two edger devices 1 are installed on the entrance side of the final stand F _o , and Fig.
This is an example in which five edger devices 1 are installed consecutively on the outlet side of F _o .

As an example of the use of the edger device according to the method of the present invention, the one shown in FIG. 4 is the most preferable, and the final stand
By installing an edger device before and after the F _o , there is the advantage of being able to significantly control the width.

When rolling at the final stand F _o is carried out under extremely light rolling, comparatively large width control can be achieved by simply installing an edger device just before the final stand, as shown in FIG.

Furthermore, in a rolling mill row with extremely good width accuracy, as shown in FIG. 6, good width control can be achieved simply by installing an edger device after the final stand F _o .

The purpose of using the edger device 1 according to the method of the present invention is as follows:
This is essentially different from the conventional V-H simultaneous rolling in thick plate rolling. In other words, roll distortion and roll flattening originally occur at the edge of the steel strip during rolling, and no matter how effective the width killing effect is initially, the effect decreases as the number of rolling passes increases. Resulting in. The method of the present invention is characterized by the fact that the edger 1 is mainly installed on the stand side of the latter stage of the continuous rolling mill row. This is what I did.

Next, a specific example obtained by the method of the present invention obtained by the arrangement shown in FIG. 4 will be described in comparison with a product obtained by the conventional method. A 25-ton material slab with a thickness of 250mm x width of 1250mm is processed by a rough mill with a thickness of 30mm x width of 1231mm.
When rolling was carried out in a finishing mill according to a rolling schedule with a target value of 4 mm in thickness and 1219 mm in width, the following results were obtained. Width accuracy is ±0.5mm against the target value of 1219mm (±5mm with the conventional method), edge drop due to the difference in plate thickness between 50mm and 10mm in the width direction from the plate edge is 0 (40μm with the conventional method), TMW yield is 0.1%
As a result of loss (1.5% loss with conventional method), 0% saw rate (0.3% with conventional method), and trim-free, pickling capacity increased by 20,000 T/M.

According to the rolling method of the present invention, the width accuracy of the steel strip can be significantly improved and the trimming process can be omitted by simply installing the three-point restraint type edger device at the required position. Width reduction makes the plate cross-sectional profile rectangular and greatly reduces edge drops, which improves yield and significantly improves production efficiency.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing step-by-step the reduction correction process using three-point restraint. FIG. 2 is a top view schematically showing a part of the structure of the edger device using three-point restraint. FIG. 3 is a front view showing one embodiment of the three-point restraint type edger device with one symmetrical side omitted. 4 to 6 are schematic explanatory diagrams showing the installation position of the three-point restraint edger device on the rolling line. 1: Three-point restraint type edger device, a: steel strip, F:
Continuous rolling mill row.

Claims (1)

[Claims] 1. A pair of roll housings are integrally fixed to a pair of sliding beds so as to be movable in the board width direction, and each roll housing is provided with two horizontal rolls whose upper and lower sides form a pair; A three-point restraint type edger device is installed in a steel strip rolling line, incorporating two vertical rolls to correct the rolling of the steel strip in the width direction and the upper and lower thickness directions at the same time. A rolling method comprising arranging at least one of the edgers described above at an entry side, an exit position, or both entry and exit positions.