JPS59183904A - Rolling method - Google Patents

Abstract

PURPOSE:To improve the width accuracy of a steel strip and to eliminate a trimming process by installing a three-point restriction type edger at the inlet and/or the outlet side of a final stand in a row of continuous rolling mills. CONSTITUTION:In installing a three-point restriction type edger 1 for performing a rolling reduction and a correction in the width direction as well as in the vertical thickness direction of a steel strip, in a strip rolling line; the edger 1 is disposed at least at the inelt or the outlet side of a final stand Fa, or are disposed at both sides according to circumstances, accordingly the number of sets of the edgers to be disposed is one or plural. In this way, the width accuracy of a strip (a) is remarkably improved to eliminate a trimming process, and an edge drop is remarkably reduced to improve yeild and production efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an arrangement in which the width accuracy, cross-sectional profile, etc. of a copper strip are controlled to a desired state 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 edger device is incorporated into a continuous rolling mill train.

During the rolling process of steel strip, it is inevitable that edge drops (thin walled parts) occur at both ends in the strip width direction. As a means of this, side trimming is carried out using rotary round blade shearing, but in this site 8 trimming, both grades of the copper strip are cut off over several millimeters to several tens of millimeters, so it is usually 1 to 10 mm. It has the disadvantage of causing a yield loss of 2%, and also has the disadvantage that, depending on the properties of the sheared surface, the edges of the product after cold rolling become saw-toothed, degrading the quality.

As a means of dealing with this drawback, the width of the copper band edge portion,
A three-point restraint method has been developed that corrects the thickness in both directions with the same Bp reduction. In this three-point restraint control method, as shown in Fig. 1(A), a steel strip α of uneven width with edges and drops b at both ends is first rolled by a vertical roll as shown in Fig. 1(B).
Correct the width by.

At this time, a slight bulge 1) d will occur at the edge of the steel strip α due to the reduction, resulting in a so-called dog-bone shape, but at the same time, as shown in Fig. 1 (C), The upper and lower horizontal rolls H press down the entire area to prevent the plate from bending and swinging, and at the same time, the raised edges d are pressed toward the center to make the entire width even.

In this method, the plate width is corrected and the plate thickness is adjusted so that the plate width W corrected at the time of 810 width reduction is not disturbed at the vertical reduction time shown in Fig. 1 fc. The correction reduction is performed at the same position as shown in FIG.

As a specific configuration of the one-point restraint type edger device, the device shown in FIG. 6 is provided symmetrically opposite the positions of both edge portions of the running steel strip a. Hereinafter, only one side will be explained. The two-point restraint type edger 1 has a roll housing 10 integrally fixed to a sliding bed 11 and positioned in the width direction of the sheet W.
The roll housing 10 is movable and has two horizontal rolls 12.1 and one vertical roll 14, which form a pair of upper and lower sides. 3 rolls 12.13,1
4 are provided on the same line in the width direction of the plate (.) in such a position that they can press and engage the steel strip a simultaneously from three directions, top and bottom. The lower horizontal roll roller is an eight-leaf roll and is supported to adjust the amount of reduction, and the rotation of the drive motor 22 is transmitted through the universal joint. The bearing is fixed, and the vertical roll [4] is also made into an idle roll.The roll no. 1 housing 10 into which these rolls are inserted is pressed toward the edge of the steel strip a by a hydraulic cylinder 15. Then, the vertical rolls 14 are made to perform the desired rolling reduction.

The three-point restraint type edger 1 constructed in this way is effectively used for removing M-band edge drops and reducing sheet crowns, but 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 As for the flow, it is controlled indirectly by using external tension and internal stress in the cross section of the steel strip, 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 shortcomings of the prior art in which a sufficient control effect could not be obtained despite the incorporation of a three-point restraint type edger device. By arranging it at the most effective position on the top, the control effect can be greatly improved.

Therefore, in the present invention, the etching device itself is of the same or very similar configuration as the prior art, but the installation position and usage form are unique, so as to obtain a remarkable product improvement value. The main focus is on

In the method of the present invention, as shown in FIGS. 4 to 6, the three-point restraint type edger 1 is connected to the continuous finishing mill
It is always arranged at least on the entrance or exit side of the final stand Fn.

They may be arranged on both the entry side and the exit side, and the number of arrangement may be one or more. Figure 4 shows one edger device 1 installed on the entrance side of final stand) Fa and its front stand F knee 1, and six more installed on the exit side of final stand F, for a total of five devices. This is an example of the installation. Also,
Figure 5 shows two edger devices 1 on the entrance side to the final stand.
Further, FIG. 6 shows an embodiment in which five edger devices 1 are successively installed on the exit side of the final stand Fn.

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 most preferable, and by installing the edger device before and after the final stand center p, there is an advantage that a large width control is possible.

When the rolling at the final stand FrL is carried out under extremely light rolling, relatively large width control can be achieved by simply installing an edger device immediately 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 Fn.

The purpose of use of the edger w1 according to the method of the present invention is essentially different from that of conventional V-H simultaneous rolling in thick plate rolling. In other words, the edges of the copper strip are originally affected by roll distortion and roll flatness during rolling, and no matter how effective the width killing effect is initially, the effect decreases as the number of rolling passes increases. Put it away. The method of the present invention is characterized by the fact that the edger 1 is mainly installed on the stand side of the rear 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 250 mm and a width of 1250 mm is processed into a rough mill with a thickness of 30 mm and a width of 1231 mm.
When rolling was carried out in a finishing mill according to a rolling schedule with a target value of 4 mm in thickness x 219 mm in width, the following results were obtained. Width accuracy is ±0 against the target value of 1219 dragons.
5 mm (±5 mm in the conventional method), edge droop due to the difference in plate thickness between 50 and 10 points in the width direction from the edge of the plate is 0 (40 μm in the conventional method), and TMW yield is 0.1% loss (in the conventional method 15% loss), no edge occurrence rate θ% (0.6% in conventional method), and as a result of trim-free, pickling capacity improved 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 two-point restraint type edger device at the required position. This makes it possible to make the plate cross-section blowfill rectangular and greatly reduce edge drops, thereby improving yield and 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. 6 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 α: Copper strip F: Continuous rolling mill row

Claims (1)

[Claims] When installing a three-point restraint type edger device in a copper strip rolling line that simultaneously corrects the rolling width of the copper strip in the width direction and the upper and lower thickness directions, Alternatively, a rolling method characterized in that at least one edger device is disposed at both an entry side and an exit side for rolling.