JPH05305308A - Cold rolling method of stainless steel strip - Google Patents

Abstract

PURPOSE:To suppress chattering generated in the stainless steel strip by arranging a strip-pressing roll in the vicinity of both sides of work rolls. CONSTITUTION:In a 20 high Sendzimir mill 1, no members are arranged to restrict the steel strip S between work rolls 2, 2' and a deflector roll 3, and vibrations from other sources are propagated to the steel strip S during the rolling operaton to cause the vibration of the strip in the vertical direction. When the incident angle theta1 of the strip S into the work rolls 2, 2' is fluctuated, the strip camber on the outlet side is also fluctuated and the wavy chattering of the strip is generated. The free span of the steel strip on the inlet side is reduced by the strip-pressing rolls 4, 4' which is arranged in the vicinity of both sides of work rolls 2, 2', the vibrations of the strip and the fluctuation of the incident angle theta1 of the strip are also reduced, leading to reduction of the chattering.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a stainless steel strip having a high surface sharpness, which is rolled by a 20-high Sendzimir rolling mill.

[0002]

2. Description of the Related Art Generally, when a steel strip is rolled by a 20-high Sendzimir rolling mill, a phenomenon that the strip corrugates in the thickness direction of the steel strip appears as shown in FIG. The undulation pitch at this time is approximately 10 to 30 mm and the wave height is approximately 25 μm. Such a wavy phenomenon of the plate is called chattering, which distorts the image reflected on the surface of the steel strip and deteriorates the sharpness. In this case, conventionally, for the steel strip in which chattering has occurred, a method for correcting the chattering that has occurred, that is, a method for performing skin pass rolling under high tension on the steel strip after rolling, or for steel strips cut into sheets The method of pulling with a stretcher is performed. However, the method of (1) has a large work roll diameter for skin pass rolling and is insufficient in effect to eliminate the corrugation of a plate having a wave height of about 5 μm. In addition, there is a problem that the appearance of the finished surface of the steel strip is impaired and the commercial value is reduced. Conventional high-strength skin-pass rolling and stretcher methods are methods for straightening, rather than fundamentally reducing and eliminating the chattering that always occurs in steel strip rolled by a 20-high Sendzimir mill. , For those with heavy chattering, there is insufficient correction,
There are problems that the cost is increased due to the increase in the number of steps and the surface quality is deteriorated due to the pulling.

For the above method, for example, Japanese Patent Laid-Open No. 58-
As disclosed in Japanese Patent No. 10104, as one of measures for preventing chattering, the total rolling reduction of the steel strip is set to 40% or less, and after annealing and pickling to soften the steel strip, A method of rolling to the product sheet thickness has been proposed, but in the method of dividing the rolling to the product sheet thickness into two times and interposing the annealing / pickling process in the middle, the number of steps increases, the cost increases due to reduced efficiency and manufacturing There are problems such as extension of the period.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for solving the problems of the above-mentioned method and reducing chatter which occurs in rolling without increasing the number of steps.

[0005]

As a result of earnest research on the cause of chattering, the present inventor has found that there is nothing to restrain a steel strip between a work roll and a deflecting roll of a Sendzimir rolling machine. Has been found to vibrate, and the angle of incidence of the steel strip with respect to the work roll changes every moment, resulting in chattering of the steel strip during rolling, and the present invention has been completed based on this finding. That is, the present invention is
In a 20-high Sendzimir rolling machine, plate pressing rolls are arranged close to both sides of a work roll to reduce vibration and amplitude of the steel strip when the steel strip is rolled, and suppress chattering occurring in the stainless steel strip. A method for cold rolling a stainless steel strip, which is characterized in that

[0006]

[Action] Normally, there is no Sendzimir rolling machine for restraining the steel strip between the work roll and the deflect roll,
Vibration from other parts is transmitted to the steel strip during rolling, and it vibrates vertically between the work roll and the deflecting roll as shown in Fig. 3,
The angle of incidence of the steel strip on the work roll changes from moment to moment. On the other hand, as for the relationship between the incident angle and the amount of plate warp on the work roll exit side, as shown in FIG. 4, when the incident angle fluctuates, the amount of plate warp on the exit side also fluctuates accordingly, causing wavy chattering of the plate. Therefore, when the amplitude of the steel strip vibration on the entrance side is large and the incident angle is large, the amount of plate warp on the exit side increases, the amplitude of the plate wave increases, and large chattering occurs. Therefore, as a measure for reducing chattering, a plate pressing roll as shown in FIG. 6 is installed in the vicinity of the work roll, and the plate pressing roll reduces the free span of the entry side steel strip, and thus the vibration of the plate, The fluctuation of the incident angle of the plate is reduced, and chatter is reduced.

[0007]

EXAMPLE An example of the present invention is shown in FIGS. The installation of the plate pressing roll of the present invention reduces the amplitude of the plate wave,
Chatter was reduced. Although the present embodiment is a method of pressing the steel strip from above with the plate pressing roll, a method of pushing up the steel strip from below with the plate pressing roll or a method of controlling the vibration of the steel strip with a pinch roll may be used. FIG. 7 shows SUS304.
It is a relationship characteristic diagram of the outgoing side wave amplitude after rolling the steel strip, and the plate thickness of the steel strip, and for each plate thickness, when using the plate pressing roll of the present invention and when not used. Shows the average value of the outgoing plate wave amplitude. According to this characteristic diagram,
When the plate pressing roll of the present invention is used, it is clear that the outgoing plate wave amplitude is small.

[0008]

As a result of rolling according to the cold rolling method for a stainless steel strip of the present invention, chatter that occurs in the stainless steel strip can be suppressed and reduced without complicated steps and without lowering the efficiency.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a configuration of equipment according to the present invention.

FIG. 2 is an enlarged view of chattering of a steel strip corrugation phenomenon after rolling.

FIG. 3 is an explanatory view of a state of vibration of a steel strip between a work roll and a deflecting roll and a change in incident angle θ ₁ accompanying it.

FIG. 4 is a relationship characteristic diagram between an incident angle θ of a steel strip with respect to a work roll and a plate warp amount of the steel strip.

FIG. 5 is a relationship characteristic diagram of an incident angle θ of a steel strip with respect to a work roll and a plate warp amount of the steel strip.

FIG. 6 is a state explanatory view of the vibration suppressing effect of the steel strip by the plate pressing roll 4 of the present invention.

FIG. 7 is a relational characteristic diagram between the plate thickness of the steel strip and the average value of the outgoing side plate wave amplitude when the plate pressing roll 4 of the present invention is used and when it is not used.

[Explanation of symbols] 1 Sendzimir rolling mill 2 Upper work roll 2'Lower work roll 3 Deflect roll 4 Inlet plate pressing roll 4'Eject plate pressing roll 5 Housing θ ₁ Incident angle of steel strip to work roll in normal case θ ₂ Incidence angle of steel strip to the work roll by the plate pressing roll 4 of the present invention S Steel strip

Claims (1)

[Claims] 1. In a 20-high Sendzimir rolling machine, plate pressing rolls are arranged close to both sides of a work roll to reduce vibration and amplitude of the steel strip when the steel strip is rolled, and to generate in a stainless steel strip. A method for cold rolling a stainless steel strip, which is characterized by suppressing chattering.