JPH08197106A - Rolling method for steel plate with projection - Google Patents

Abstract

PURPOSE: To provide a method for rolling steel plates with projections by which the decrease in the height of the projections in the end parts of width is prevented without changing the shape of roll caliber in the width direction and the uniform height of the projections in the width direction is obtained. CONSTITUTION: In the rolling method of the steel sheet with the projections by which rolling for reducing thickness is executed with a horizontal rolling mill 10 in which a roll having plural lines of the calibers 11A which are continued in the circumferential direction in the width direction, rolling for reducing the width is executed with a edger mill 20 preceding to rolling for reducing thickness with a horizontal rolling mill 10 and the steel sheet whose thickness in the end parts of width is increased by rolling for reducing width is supplied to rolling for reducing thickness with the horizontal rolling mill 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rolling a steel sheet with projections, which carries out sheet thickness reduction rolling by a horizontal rolling mill incorporating a roll having a plurality of calibers continuous in the circumferential direction in the width direction.

[0002]

2. Description of the Related Art A steel plate with projections has a plurality of parallel projections on the surface of the plate. Not only does the strength increase due to the reinforcing effect of the projections, but when it is used in combination with concrete,
Since concrete is filled between the protrusions to obtain a large joint strength, it is widely used as a material for civil engineering and construction materials, and its demand has been rapidly increasing in recent years.

In FIG. 2, 1 is a material steel plate, 2 is a steel plate with protrusions, and 3 is a roll. Conventionally, the steel plate 2 with protrusions is
As described in Japanese Patent Application Laid-Open No. 60-124406, a horizontal rolling mill incorporating a roll 3 having a plurality of calibers 3A continuous in the circumferential direction in the width direction is used as a raw material steel plate 1 having a substantially rectangular cross section.
Is manufactured by rolling the steel sheet.

[0004]

However, the heights of the plurality of protrusions 2A of the steel plate 2 with protrusions manufactured by the conventional rolling method are not uniform in the width direction. A typical example of the widthwise distribution of the projection height is shown in FIG. The desired height of the protrusion is obtained at the center of the plate, whereas the height of the protrusion is considerably smaller near the ends of the plate than at the center. At the end of the steel plate where the projection height is small, not only the strength of the steel plate itself decreases, but also the joint strength with concrete decreases. For this reason, the steel plate ends must be cut off,
The product yield was extremely poor.

In order to make the projection height in the width direction uniform,
Japanese Patent Laid-Open No. 60-124406 discloses a method of changing the caliber width, the caliber pitch or the caliber angle in the width direction of the roll. However, in this method, since it is necessary to use rolls having different caliber shapes corresponding to various product widths, it is necessary to prepare a large number of rolls, and it is necessary to frequently perform roll exchange. There was a problem.

The present invention provides a method for rolling a steel sheet with protrusions, which prevents a decrease in the protrusion height at the plate width end without changing the roll caliber shape in the width direction to obtain a uniform protrusion height in the plate width direction. The purpose is to provide.

[0007]

The present invention according to claim 1 is a steel plate with projections for performing plate thickness reduction rolling by a horizontal rolling mill incorporating a roll having a plurality of calibers continuous in the circumferential direction in the width direction. In the rolling method, the plate width reduction rolling is performed by the edger rolling machine prior to the plate thickness reduction rolling by the horizontal rolling machine, and the steel sheet having the plate width end portion thickened by the plate width reduction rolling is produced by the horizontal rolling machine. It is used for sheet thickness reduction rolling.

The present invention according to claim 2 is the same as in the present invention according to claim 1, which is necessary so that the distribution of projection heights obtained by the plate thickness reduction rolling in the plate width direction becomes substantially uniform.
The width reduction amount of the strip width reduction rolling is previously investigated for each rolling condition, and by adjusting the roll opening of the edger rolling machine, the width reduction amount suitable for the rolling condition is set to set the strip width reduction rolling. Is to do.

[0009]

First, the cause of the conventional problem that the protrusion height is smaller at both ends of the plate width than at the central part is considered, and it is found that this problem is caused by the metal flow in the width direction at the ends of the plate width. It was That is, during the plate thickness reduction rolling using the above-mentioned caliber roll, the end face in the plate width direction becomes a free deformation surface that is not restricted by the upper and lower rolls. For this reason, the metal flow in the width direction is larger at the plate width end than in the center part, and the metal escapes in the width direction, so that the degree of filling in the caliber becomes low, and as a result, the protrusion height is higher than that in the center part. Will also be lower.

In order to prevent the free deformation at the end of the plate width, it is necessary to restrain the plate end at the same time as the plate thickness reduction by the upper and lower rolls, but this is practically impossible due to the large scale of mechanical equipment.

Therefore, in order to compensate for the lack of metal at the plate end portion due to the metal flow in the width direction when the plate thickness is reduced, it was considered effective to use a material in which the plate end portion is thickened in advance as compared with the plate central portion. . The method of making the plate end portion relatively thicker than the plate center portion is to perform edging rolling in the plate width direction (Fig. 4).
(A)), press working in the sheet width direction (Fig. 4 (B)), and partially roll-roll the sheet width central portion (Fig. 4).
(C)) and various other methods are possible. Pressing is a process that is intermittent and has the drawback that productivity is difficult to increase.Therefore, although it can be used for thick and short materials such as slabs, it is suitable for long materials such as seat bars. Is not suitable for. In addition, the partial strip thickness rolling in the central part of strip width is
Although there is no problem in productivity, it is necessary to change the partial rolling width according to the change in the product width of the steel plate with protrusions, it is necessary to prepare a large number of partial rolling rolls, and frequent roll replacement is required. There are problems such as being there.
The method of edging rolling utilizes that the edge portion of the plate increases in thickness during edging rolling and becomes a so-called dog bone shape. Since edging rolling is a continuous process using edging rolls, it has high productivity, and changes in strip width can be easily dealt with by adjusting the rolling position of the edging rolls.

As described above, the present invention relates to a rolling method for producing a steel plate with protrusions by plate thickness rolling using a roll having a plurality of calibers continuous in the circumferential direction in the width direction. In the thickness reduction rolling, the metal flow in the strip width direction caused a shortage of the projection height at the strip width end. By subjecting the thickened steel plate to the plate thickness reduction rolling, the metal flow in the width direction at the time of plate thickness reduction rolling is supplemented, and the shortage of the projection height at the plate end is prevented.

[0013]

FIG. 1 is a schematic view showing a rolling method for a steel plate with protrusions according to the present invention. 1 is a raw steel plate, 2 is a steel plate with protrusions, 11 is a caliber roll of a horizontal rolling mill 10, 21 is an edger rolling mill 20. Edging roll of. The caliber roll 11 of the horizontal rolling mill 10 has a plurality of calibers 11A continuous in the circumferential direction in the width direction. In the present invention, prior to the plate thickness reduction rolling by the caliber roll 11 of the horizontal rolling mill 10, the plate width reduction rolling is performed by the edging roll 21 of the edger rolling machine 20, and the plate width end portion is thickened by the plate width reduction rolling. The obtained steel sheet is subjected to sheet thickness reduction rolling by the caliber roll 11 of the horizontal rolling mill 10. In FIG. 1, 1A is a dog bone portion formed on the plate end of the raw steel plate 1, and 2A is a plurality of protrusions formed on one side of the steel plate 2 with protrusions.

Therefore, in order to confirm the effect of the present invention,
First, a laboratory scale rolling was performed. Hard lead, which is said to be capable of accurately simulating the deformation characteristics of hot steel, was used as the material to be rolled, and rolling experiments were conducted under the rolling conditions shown in Table 1. Further, the difference between the plate widths before and after edging was defined as "width reduction amount", and the plate edge thickness increase amount (dogbone amount) was adjusted by the width reduction amount as shown in FIG. Fig. 6 shows the widthwise distribution of the projection height after reduction of the plate thickness (displayed as the value converted to the actual machine in consideration of the scale ratio with the actual machine).
In other words, in the case of the material by the conventional method in which the width reduction is not performed, the projection height at the plate end portion after the plate thickness reduction is smaller than that at the central portion, and the target value is not obtained. On the other hand, the material with a width reduction of 3 mm has almost the same protrusion height at the plate edge and the center, and the protrusion height above the target is obtained over the entire width. Furthermore, 5m
The material with width reduction of m was slightly higher than the center in the height of protrusions at the plate edge, and the thickness increase of the plate edge due to width reduction was slightly excessive. The height is obtained. In this experiment, the optimum width reduction amount was 3 mm, but the optimum width reduction amount may differ depending on the plate thickness, plate width, plate thickness reduction amount, and caliber roll shape. It is preferable that the width reduction amount at which the distribution of the projection heights in the plate width direction becomes substantially uniform is previously investigated for each rolling condition, and the width reduction amount is set to an optimum value by adjusting the edger roll opening.

[Table 1]

Next, based on the results of the laboratory-scale rolling experiment,
The hot steel rolling with the actual rolling mill was performed under the rolling conditions shown in Table 2. FIG. 7 shows the distribution of protrusion heights in the plate width direction after the plate thickness reduction rolling. When the width reduction amount of the conventional method is 0 mm (no width reduction), the projection height at the edge of the plate width is small and the target value is not obtained.
With the width reduction amount of 20 mm to which the present invention is applied, the projection height at the end portion of the plate width is slightly smaller than the center, but the projection height equal to or higher than the target value is obtained. Furthermore, when the width reduction amount was 40 mm, the projection height distribution was almost uniform in the plate width direction. Thus, by performing the plate width reduction rolling prior to the plate thickness reduction rolling, it is possible to prevent a decrease in the protrusion height at the plate end portion, and to make the protrusion height distribution in the plate width direction uniform. It could be confirmed.

[Table 2]

In this embodiment, the width reduction amount in the range of 5 mm or less on the laboratory scale and 40 mm or less on the actual rolling scale is set. However, as described above, the optimum width reduction amount changes depending on the rolling conditions. It is not limited to the range of the width reduction amount in this embodiment. Further, although the caliber roll is used for the upper roll in the present embodiment, the present invention is also applied to the case where the caliber roll is used for the lower roll and the double-sided projection steel plate is manufactured using the caliber roll for the upper and lower rolls. can do. Further, in the present embodiment, the case where the projection height of 4.5 mm or more is required is taken as an example, but the present invention is intended to prevent a decrease in the projection height at the end of the plate width, and a larger projection height. Can also be applied when required.

[0017]

According to the present invention, in producing a steel plate with protrusions by plate thickness reduction rolling using a caliber roll,
It is possible to make the distribution of the projection heights in the plate width direction uniform without impairing the rolling efficiency, to prevent a shortage of the projection height at the plate end, reduce the amount of cut-off at the plate end, and improve the product yield.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a rolling state according to the present invention, which comprises strip width reduction rolling and subsequent sheet thickness reduction rolling;
(A) is an overall view, (B) is a dogbone part, (C) is a protrusion, and (D) is a roll caliber.

FIG. 2 is a schematic view showing a caliber roll and a steel plate with protrusions used for plate thickness rolling, (A) is an overall view, (B) is a protrusion, and (C) is a roll caliber.

FIG. 3 is a diagram showing a plate width direction distribution of protrusion heights of a steel plate with protrusions according to a conventional method.

FIG. 4 is a schematic view showing a method for making the plate thickness at the end of the plate width relatively thicker than that at the center, (A) is a method of the present invention by plate width reduction rolling, (B) ) Is a method by width pressing, and (C) is a method by partial rolling of the central part of the plate width.

FIG. 5 is a diagram showing a change in strip thickness distribution due to strip width reduction rolling during a laboratory-scale rolling experiment.

FIG. 6 is a diagram showing the effect of the present invention during a laboratory-scale rolling experiment in comparison with the conventional method.

FIG. 7 is a diagram showing the effect of the present invention in comparison with a conventional method at the time of a confirmation experiment on an actual rolling mill scale.

[Explanation of symbols]

 1 Material Steel Plate 1A Dogbone Part 2 Steel Plate with Projection 2A Projection 10 Horizontal Rolling Machine 11 Caliber Roll 11A Caliber 20 Edger Rolling Machine 21 Edging Roll

Claims (2)

[Claims] 1. A method for rolling a steel sheet with projections, which comprises performing a roll thickness rolling by a horizontal rolling mill incorporating a roll having a plurality of calibers continuous in the circumferential direction in the width direction, wherein the horizontal rolling mill reduces the plate thickness. Prior to the above, the plate width reduction rolling is performed by the edger rolling machine, and the steel sheet having the plate width end portion thickened by the plate width reduction rolling is subjected to the plate thickness reduction rolling by the horizontal rolling machine. Rolling method. 2. The width reduction amount of the plate width reduction rolling necessary for the distribution of the projection heights obtained in the plate thickness reduction rolling in the plate width direction to be substantially uniform is previously investigated for each rolling condition. The method for rolling a steel plate with protrusions according to claim 1, wherein the plate width reduction rolling is performed by adjusting a roll opening of an edger rolling mill to set a width reduction amount that matches rolling conditions.