JPS6345881B2 - - Google Patents

Description

Detailed Description of the Invention ``Object of the Invention'' The present invention relates to a method for preventing warping of a steel plate with projections on one side, which eliminates troubles caused by warpage when rolling a steel plate with projections on one side with a caliber roll. This is a steel plate with protrusions on one side.

Industrial applications Rolling technology for steel plates with protrusions on one side.

Conventional technology To obtain a steel plate with protrusions on one side, the protrusion surface of the material is rolled by a caliber roll.In this case, the material on the protrusion surface is restrained by the caliber roll so that the material exit speed is lower than the rolling speed. On the other hand, on a flat surface, the material exit speed is generally faster than the caliber roll peripheral speed. For this reason, the rolled material is warped with the protruding surface facing inward, and sometimes the rolled material is even wrapped around the caliber roll.The rolled material with such warpage is not only defective, but also damaged by peripheral equipment. This will cause damage to the equipment. In order to prevent such sheet warping, proposals have been made to make the upper and lower work rolls different diameters, to roll the upper and lower rolls at different circumferential speeds, or to change the coefficient of friction between the upper and lower rolls.

Problems to be Solved by the Invention However, in any of the above methods, only a certain degree of effectiveness is recognized for a simple flat steel plate, and in rolling a steel plate with projections on one side, it is necessary to reduce the restraint of the caliber roll. Therefore, almost no effect is observed in reducing plate warpage as described above, and prevention of plate warpage has become an important issue in the production of steel plates with projections on one side.

"Structure of the Invention" Means for Solving the Problems When rolling a steel plate with protrusions formed on one side using a caliber roll, rolling with a reduction amount lower than a predetermined reduction at the time of biting from the edge of the steel plate, A method for preventing warping of a steel plate when rolling a steel plate with projections on one side, characterized by rolling the steel plate back to a predetermined reduction amount after the self-weight restraint of the derived steel plate is obtained.

Function By rolling the steel plate at a lower reduction than the predetermined reduction when the steel plate is bitten from the edge, it is possible to perform rolling that appropriately prevents the plate from warping at the start of rolling.

After the steel plate led out to the exit side is subjected to self-weight restraint, even if the steel plate is rolled back to the predetermined reduction amount, the occurrence of sheet warpage can be similarly prevented by the self-weight restraint.

Embodiment To specifically explain the present invention as described above with reference to the attached drawings, rolling of a steel plate with projections on one side is schematically shown in FIG. The steel plate 3 is caught between the rolls 2 and rolled, but the rolled steel plate has a strong tendency to become warped.
The results of studies conducted by the present inventors regarding the relationship between such plate warpage and the reduction amount are shown in FIG.

That is, in this Figure 1, curve a is the entry side plate thickness 10
Indicates the case where mm, b is 15 mm, and c is 20 mm, broken line A...
A indicates roll wrapping, but even though the warp curvature varies depending on the thickness of the steel plate on the entrance side, the warp curvature changes significantly depending on the amount of reduction, and roll wrapping may occur. Become. However, in spite of such a warp curvature, in actual rolling, if warpage can be appropriately prevented at the initial stage of rolling, that is, at the top part of the material steel plate 3, then the dead weight of the discharged steel plate will be reduced. It has become possible to effectively prevent the occurrence of warping due to restraint, and it has been confirmed that there is no problem in threading the sheet.

Therefore, the present invention attempts to roll a steel plate with projections on one side as described above by effectively utilizing these relationships.
According to many experimental results, the rolling reduction amount Δh between 5 m and 5 m is influenced by the entrance plate thickness, and is actually 5 to 15% of the entrance plate thickness h, and after such rolling, it is necessary to return to the predetermined reduction rate. By performing the rolling process, it is possible to roll the sheet without warping.

The rolling extension of the low-pressure lower part as mentioned above affects the rolling yield because the prescribed rolling reduction is not achieved, and it is natural that it is preferable to keep it as short as possible, but this part is originally an unsteady part, and the plate This corresponds to the portion that is cut off due to thickness, plate width accuracy, and flaws during coiler winding, so there is little substantial yield loss.
In fact, the amount of cut-off parts due to board warping is greatly reduced, and the yield is improved and the benefits are very large by preventing troubles caused by board warping. The present invention can exhibit a very favorable effect in a rolling mill equipped with a high-speed rolling position changing device, such as a hydraulic rolling mechanism.

Further, in a rolling mill that does not have the above-mentioned high-speed reduction position changing device, if there is a possibility that the low reduction region as described above becomes long, a guide means 4 as shown in FIG. 3 is separately adopted. That is, a guide means 4 is provided on the exit side of the caliber roll to prevent warping of the steel plate 3. It is effective that this guide means 4 is close to the exit side of the caliber roll, and has a length of 2 to 3 m in the rolling direction. It is necessary to have up and down, in order to follow the change in caliber roll position.
It is preferable to provide an adjustment mechanism that allows for forward and backward movement. Even in the case of a steel plate with a protrusion shape that tends to wrap around the roll, by reducing the rolling reduction at the time of starting and using such a guide means 4, warping can be appropriately prevented and stable rolling can be performed. confirmed.

"Effects of the Invention" According to the present invention as explained above, it is possible to effectively prevent warping of this type of steel plate with projections on one side during rolling, eliminate troubles or decrease in yield due to warpage, and provide an advantageous steel plate with projections. This invention is industrially very effective because it allows for accurate production of.

[Brief explanation of the drawing]

The drawings show the technical contents of the present invention, and FIG. 1 is a chart showing the relationship between the rolling reduction amount and the warp curvature during rolling of a steel plate with projections on one side, FIG. 2 is a side view of the rolling state, and FIG. FIG. 3 is a side view similar to FIG. 1 showing another embodiment according to the invention. However, in these drawings, 1 is an upper roll which is a caliber roll, 2 is a lower roll, 3 is a steel plate,
4 indicates a guide means.

Claims (1)

[Claims] 1. When rolling a steel plate with protrusions formed on one side using a caliber roll, the self-weight of the steel plate is rolled at a reduction amount lower than the predetermined reduction when the steel plate is bitten from the edge of the steel plate. A method for preventing warpage during rolling of a steel plate with projections on one side, characterized by rolling the steel plate back to a predetermined reduction amount after a state in which restraint is obtained. 2. A method for preventing warpage during rolling of a steel sheet with projections on one side, as set forth in claim 1, wherein a guide means is provided on the outlet side of the caliber roll to prevent warpage of the steel sheet.