JPS63264203A - Method for tandem cold rolling - Google Patents

Abstract

PURPOSE:To reduce a rolling interruption time for even a small rolling unit and to improve the productivity by proceeding rolling at the roll stand one less than the final stand at the time of opening and changing the final stand rolls at a changing point of a strip surface quality in tandem cold rolling. CONSTITUTION:In the case of continuously rolling a strip 1 by a tandem cold mill and changing the surface quality from bright to rough, as an example, final stand work rolls 3 are opened and changed from a bright roll to a rough surface roll and the rolling proceeds by bright rolls of a stand 10 being one less than the final stand. It is also performable that a rough surface is rolled by drafting the final stand roll and a bright surface is rolled by the roll one less than the final roll with the final stand roll being opened. A rolling interruption time caused by roll changing is remarkably reduced and the productivity of rolling for even a small rolling unit is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tandem cold rolling method for successively rolling metal strips with different surface properties.

[Conventional technology]

In conventional cold rolling methods, when producing strips with different surface properties, rolling units of several hundred to several thousand tons, called a rolling schedule, are set up, and the rolling rolls are rearranged for each rolling unit to achieve the desired surface properties. The strips were being rolled.

Regarding the rearrangement work of this rolling roll,
There is a method as described in Japanese Patent No. 3135.

In such conventional methods, when it is desired to produce strips having different surface properties in a short time in order to set a rolling schedule, the rolling rolls must be rearranged. As a result, rolling was interrupted during the recombination work, resulting in longer waiting times in the manufacturing process. Additionally, if a situation arises in which strip with a given surface texture must be produced urgently, the default rolling unit may have to be divided unless the required surface texture is compatible with the currently running rolling unit. This resulted in an increase in the time required to rearrange the rolling rolls, and a decrease in the efficiency with which the rolling rolls were used.

A conventional method for alleviating such interlayers is to shorten the time required for changing rolls as much as possible. For example, increasing the operating speed of the equipment, using a plate-based recombination method instead of a plate-less recombination method (saving time on plate cutting and reconnection), and removing the rolling mill while rolling continues (
(See Japanese Patent Publication No. 53-34582).

[Problem that the invention seeks to solve]

However, with such conventional methods, although the time required for roll rearranging is reduced, if the rolling unit is made very small, the number of rolls used increases significantly, and even though the time is reduced, it takes a considerable amount of time. This cannot be expected to fundamentally solve the problem of reduced manufacturing efficiency unless a certain rolling unit is maintained.

Therefore, the present invention makes it possible to realize frequent changes in the product surface in small rolling units by not significantly reducing the operating rate of the rolling mill and the rolling roll usage efficiency even when the rolling units are made very small. purpose.

[Means for solving problems]

In order to achieve this object, the tandem cold rolling method of the first invention of the present application is such that when strips having different surface textures are continuously cold rolled by a tandem cold rolling mill, a final rolling stand is provided at a point where the surface texture changes. The rolling rolls are opened, and in this state, the required amount of rolling is performed with the rolling rolls on the stand before the final rolling stand. During this time, the rolling rolls on the final rolling stand are replaced with rolling rolls having different surface properties, and then At the surface property change point, the rolling rolls of the final rolling stand are brought into use and rolling is performed, and this procedure is repeated to finally change the rolling state to the original rolling state.

Further, in the tandem cold rolling method of the second invention of the present application, when strips having different surface properties are continuously cold rolled by a tandem cold rolling machine, rolling of a stand before the last stand at a point where the surface properties change is performed. The rolling roll of the final rolling stand, which has a surface different from that of the roll, is opened, and in this state rolling is performed with the rolling roll of the stand before the final rolling stand, and at the next point where the surface properties change, the rolling roll of the final rolling stand is opened. to put it into use
＃Slightly.

In either of the first and second inventions, the stopping time of the final stand can be shortened by carrying out the operation of opening or using the rolling rolls during rolling without stopping the rolling mill. , rolling efficiency can be improved.

In addition, in the present invention, the "usage state" refers to the state in which rolling is actually performed using a rolling roll.

[Effect]

FIG. 1 shows a reshuffling procedure according to the first invention of the present application in a case where a plurality of roll reshuffles are continued as rolling progresses for each rolling unit.

Referring to Fig. 1, in Step 1, the rolls of the final rolling stand are opened, and while rolling is performed in this state, in Steps 3 and 4, the rolls of the final rolling stand are replaced with rolls having different surface properties. is brought into use, and after rolling a predetermined amount shown in Step 5, the rolling state is again changed to the rolling state using the original rolling rolls held on the roll changing device in Steps 6 to 8. By doing this, the roll changing procedure becomes a little complicated, but the functionality of the product production of the tamper rolling mill can be improved.

The surface texture of a cold-rolled strip is usually determined by the surface texture of the rolling roll on the final stand, so if only the rolling roll on the final stand is changed as in the present invention, the rolling rolls on the other rolling stands will be changed. remain the same)
It is possible to change the surface properties of the IJ tube.

By the way, when rolling is performed without using the rolling roll of the last stand, the surface texture of the strip is determined by the surface texture of the rolling roll of the previous stand.
Generally, the rolling rolls of stands other than the final stand are blind rolls that have been ground to a smooth finish from the viewpoint of rolling performance, so the surface quality of the strip is also bright. Therefore, in the rolling method of the present invention, a strip with a bright finish is rolled between rolling units requiring different surface textures, but one of the adjacent rolling units has a bright finish, as in the case of FIG. In this case, there will be no problem. In addition, if this is not the case, a method may be adopted in which a strip requiring bright finishing is inserted between rolling units, and the final stand rolls are opened and rearranged during the rolling.

The procedure for changing the rolls in the first method of the present invention is the same as the procedure for changing the rolls in the conventional method in that it involves changing the rolls for each rolling unit. It has the following characteristics: That is, even if the rolling amount by the same roll becomes large because the rolls are reused, and even if the rolling unit is reduced to create different surface textures, the usage efficiency of the rolls does not decrease. Furthermore, since the rolling rolls of the final stand are replaced while the bright finished material is being rolled, even if the rolling unit is reduced in order to create different surface textures, there is no increase in the downtime of the rolling mill due to rolling roll replacement.

In addition, in addition to the method of the first invention of the present application, when opening the roll or returning to the use state, for example,
By using the method of changing plate thickness during running as shown in Japanese Patent No. 4582, the procedure shown in FIG. 1 can be carried out without stopping the rolling mill, and the above effects can be further enhanced.

The method of the second invention of the present application makes some changes to the method of the first invention and achieves a similar effect with fewer steps, although there are restrictions on application. The procedure is shown in FIG. In Fig. 2, the rough surface roll of the final rolling stand is in an open state in step 2, and the material rolled in this state is rolled by the rolling roll (bright surface) of the rolling stand one stage before the final stand. Bright finish. After the rolling of the bright finish material is completed, the rough surface roll of the final stand is returned to its original position in step 4, and the process moves to rolling of the rough surface finish material.

The feature of the method of the second invention is that under conditions that would require rolling roll changes in the conventional method, the operational flexibility of a tandem rolling mill is utilized to avoid roll changes; The purpose is to change the finished surface according to the use by turning on and off the final stand rolling roll and changing the pass schedule of the tandem rolling mill accordingly or according to the material. By doing so, the so-called operational freedom of the tandem rolling mill is greatly improved, and it becomes possible to operate the rolling mill with functions for producing excellent products.

When using the above method, the bright finish material is rolled with one less stand in the rolling mill. Therefore, the rolling capacity E1, which is smaller than Eo, is not the rolling capacity (inlet side plate thickness/outlet side plate thickness) Eo that the tandem rolling mill has.
It can only be rolled within the range of . Therefore, in advance, E
A rolling unit consisting only of material to be rolled in the range of 1 must be planned. In the cold rolling process, the elongation ratio (inlet side plate thickness/outlet side plate thickness) e of the material ranges over a wide range from 2 to 10, and it is possible to plan the rolling unit as described above. Of course, in the long term E≧e>
Since it is necessary to roll the material under the condition of E It is possible to demonstrate this.

〔Example〕

Hereinafter, an apparatus for carrying out the method of the present invention will be described with reference to embodiments shown in the drawings.

FIG. 3 is a drawing showing the reassembled state of the rolling rolls of the final stand. In the figure, 1 is a rolled material, and 7 to 10 are first to fourth stands, respectively.

As shown in the same figure, rolling rolls 3A and 3B of the final stand
is supported by chocks 4A, 4B having wheels 5A, 5B, and in the rearranged state, the chocks 4A, 4B have wheels 5A, 5B.
4B is riding on rails 6A and 611. Chocks 4^ and 4B are a pair of upper and lower chocks, but each chock 4^ is upper and lower.

4B are not interconnected, so they can run on separate rails and be pulled out of the rolling mill. At this time, there is no interference with the rolling material 1, so the rolling rolls 3A, 3B
It is possible to continue rolling using the other rolling stands 7 to 10 even during the reshuffling. 2^ and 2B in Figure 3 are the auxiliary rolls of the final stand.

In order to apply the method of the present invention, a rolling mill needs to be equipped with a roll changing device having such characteristics, a so-called plated roll changing device.

In addition, in the rolling method of the present invention, it is necessary to roll without using the rolling rolls of the AM stand, but for this purpose, the rolling mill drive electrical system must be designed to be able to drive with the final stand separated. must be maintained. However, it is easy to design in this way or to add such a function.

Next, FIG. 4 shows the final rolling stand and its rearrangement device, and FIG. 4(a) is a front view, and FIGS. 4(a) and 4(b) are schematic plan views. In these figures, 11 indicates a final rolling stand, and 12 indicates a driving device for the rolling rolls 3A and 3B. On the side of the final rolling stand 11, a rolling roll changing truck 14 is arranged so as to be movable forward and backward by a truck running cylinder 16, and on the truck 14, a rolling roll changing frame 15 equipped with a rail is provided. It is being and,
On the same frame 15, standby rolling rolls 13^, 13B are installed.
is installed.

In FIG. 4, when replacing the rolling rolls 3A and 3B, the upper and lower rolls 3A and 3B are placed on the replacement cart 14.
The rollers are separately run on the rails on the frame 15 and pulled out, and after being shifted laterally at that position to be replaced with other rolling rolls 13A and 13B, they are inserted into the housing of the rolling stand 11 again. Furthermore, the same figure (b
), the rolling rolls 3A and 3B (hereinafter referred to as roll A) pulled out from the rolling stand 11 will be explained.
) is placed at the first position al of the frame 15 on the recombination truck 14. Next, by shift (shift) F for one position, roll A is at the first auxiliary position a.

However, at the same time, other rolling rolls 1.3A and 13B (hereinafter referred to as roll B) placed at the second position a2 move to the first position al, become ready for insertion, and are inserted. In the next roll change after the material to be rolled by the rolling roll B is finished, the rolling roll B is retracted by the same operation as above, and the rolling roll A is inserted again. The third position al of the frame 15 on the recombination truck 14 is used as a preparation position for unused rolling rolls. If it is suddenly necessary to change the roll assembly due to a rolling accident, shift operation is performed so that the spare roll prepared in advance at the third position a3 comes to the first position al, and then the rolling stand 1 is moved.
Insert into 1.

The device shown in Fig. 4 makes it possible to hold both the roll scheduled for reuse (either rolling roll A or B) and the reserve roll on the recombination device, making it possible to hold the roll scheduled for reuse (either rolling roll A or B) and the reserve roll, which is essential for rolling operations. The method of the first invention of the present application can be carried out more effectively while the roll is in a prepared state.

In the case of a production schedule in which bright finishing and rough finishing rolling units are processed alternately, implementation comparison between the conventional method and the case where the rolling units are subdivided and the first method or the second method of the present invention is applied. Examples are shown in the table. In the same table, in the conventional method, the rolling roll has a limit (100
0) Replaced in case of rolling unit change) or rolling unit change.

Next, when the first method of the present invention is implemented, the rolling unit is small, so the number of roll rearrangements increases significantly, but the downtime per roll is shortened, so the downtime due to roll rearrangement is decreases.

Next, when implementing the second method of the present invention, the rolling rolls of the final stand will not be used in most cases in the case of rolling bright finishing materials, and the number of rearranging rolls of the final stand will be limited. It is characterized by the fact that the limit is only due to the surface roughness of the face roll, and it is greatly reduced, and the total stop time is also reduced.

Table [Effects of the Invention] As explained above, in the present invention, when strips with different surface textures are continuously cold rolled by a tandem cold rolling mill, the rolling rolls of the final rolling stand are The required amount of rolling is carried out with the stand open, and during this time the rolling roll in the final rolling stand is replaced with a rolling roll having a different surface texture, or the rolling roll is left on standby, and the next change in surface texture is carried out. At this point, rolling is performed with the original rolling rolls in use. Therefore, it is possible to continuously roll strike IJ tubes with a desired surface texture using the same rolling mill. Therefore, there is no reduction in the usage efficiency of the rolling mill, and manufacturing can be carried out based on a manufacturing schedule with a smaller rolling unit number. Compared to the conventional method, the increase in manufacturing time due to waiting for rolling units can be reduced to, for example, 1/10 (2,500 yen). )n/250
) n).

In addition, by performing the operation of opening or using the rolling rolls during rolling without stopping the rolling mill, it is possible to further reduce the downtime of the rolling stand, and the effects of the application are even greater. .

In addition, in the conventional method, the rolling rolls were used almost to the limit of surface wear or fatigue, and then taken out of the rolling mill and ground. By continuing rolling and substantially avoiding loss due to roll change time, there is also the effect that roll changes can be made frequently and the same roll can be reused several times.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the roll rearranging method of the first invention of the present application, FIG. 2 is an explanatory diagram showing the roll rearranging method of the second invention of the present application, and FIG. 3 is an explanatory diagram showing the method of the present invention. FIG. 4 is a diagram showing the configuration of the final rolling stand of a tandem rolling mill in an apparatus for carrying out the method of the present invention. Patent Applicant: Nippon Steel Corporation Agent: Kei Ko (and 2 others) Figure 1 Figure 2 Figure 3 Figure 4 (b)

Claims (1)

[Claims] 1. When continuously cold rolling strips with different surface textures using a tandem cold rolling mill, the rolling rolls of the final rolling stand are opened at the point where the surface texture changes, and the final rolling is carried out in this state. The required amount of rolling is performed with the rolling rolls on the stand in front of the stand, and during this period, the rolling rolls on the final rolling stand are replaced with rolling rolls having a different surface texture, and at the next point where the surface texture changes, the rolling rolls on the final rolling stand are replaced. A tandem cold rolling method characterized in that the rolling state is changed to the rolling state using the original rolling rolls by repeating this procedure. 2. The operation of putting the rolling roll in the open state or in use state,
The tandem cold rolling method according to claim 1, wherein the tandem cold rolling method is carried out during rolling without stopping the rolling mill. 3. When continuously cold rolling strips with different surface textures using a tandem cold rolling mill, the rolling rolls on the final rolling stand that have different surfaces from the rolling rolls on the stand before the final stand at the point where the surface texture changes are used. A tandem cold rolling method characterized in that the roll is set in an open state, and in this state rolling is performed with a roll on a stand before the final rolling stand, and the roll on the final rolling stand is brought into use at the next point where the surface property changes. Rolling method. 4. The operation of putting the rolling roll in the open state or in use state,
4. The tandem cold rolling method according to claim 3, wherein the tandem cold rolling method is carried out during rolling without stopping the rolling mill.