JP5419648B2 - Shape control method in kiss rolling - Google Patents

Description

  The present invention relates to a shape control method in kiss rolling.

As is well known, when rolling a rolled material such as a foil material, a multi-high rolling mill is used. As the multi-high rolling mill, a “cluster type multi-high rolling mill” or the like in which an intermediate roll supporting the work roll and a backup roll supporting the intermediate roll spread in a fan shape like a bunch of straw is used.
In the rolling of the foil material by such a multi-stage rolling mill, the shape control of the foil material using coolants having different temperatures is performed.

  Patent Document 1 is a typical example of such a technique, and n pieces are arranged in the sheet width direction on the inlet side of the rolling roll by an output signal of the shape detector arranged in the sheet width direction on the rolling roll outlet side. In the case of controlling the shape of the rolled material by adjusting the cooling water flow rate of the roll cooling device, when each of the n roll cooling devices is adjusted, Necessary to store the influence coefficient on the plate shape and to make the shape in the width direction of the rolled material sheet on the rolling roll exit side using the output signal of the shape detector and the stored influence coefficient. A technique for calculating the amount of cooling water of each of the n roll cooling devices and controlling the cooling device based on the calculation result is disclosed.

  Patent Document 2 discloses a work roll that rolls a rolled material, a coolant device that supplies coolant at least on the entry side of the rolled material, a shape detector that measures the plate shape after rolling, and mechanical control that controls the plate shape. A coolant header row in which the diameter of the work roll is 0.16 times or more and less than 0.3 times the maximum plate width that can be rolled, and the coolant device includes a plurality of nozzles arranged in the plate width direction. And a plurality of supply systems each having a means for adjusting the flow rate and temperature of the coolant, and a control device for controlling the mechanical control means and the coolant device based on the detection value of the shape detector. Disclosed is a rolling mill. According to Patent Document 2, it can be seen that the ratio D / W of the width W of the rolled material to the work roll diameter D is 0.16 to 0.3, so that the coolant can be controlled efficiently.

  Further, Patent Document 3 discloses that when a shape of a rolled thin sheet is controlled by spraying a coolant toward a work roll of a rolling mill, the predetermined width is within the work area of the work roll. A coolant set at a temperature lower than the temperature of the work roll is sprayed on the region excluding both ends, and the both ends are adjacent to the non-rolling region of the work roll. A method for controlling the shape of a rolled thin sheet is disclosed in which a coolant set at a temperature higher than the temperature of the workpiece is sprayed into a region excluding a region over a predetermined width adjacent to both ends. According to Patent Document 4, an excessive ear wave can be prevented by applying hot coolant outside the width of the rolled material and cooling the inside in the width direction of the rolled material.

JP-A-55-42161 JP 2004-66310 A JP-A-3-297507

However, in reality, it is difficult to apply the techniques of Patent Documents 1 to 3 to a multi-high rolling mill having a small-diameter work roll.
First, since the work roll of the rolling mill has a small diameter and a plurality of rolls are arranged in a narrow region, it is difficult to appropriately arrange the coolant nozzle. It is extremely difficult to arrange n shape detectors in the sheet width direction and n roll cooling devices in the sheet width direction on the rolling roll entrance side.

Moreover, it is difficult to apply the technique of Patent Document 2 to a small diameter roll of D / W <0.1, such as a work roll diameter D = 30 to 60 φmm and a plate width W = 500 mm. Is disclosed.
The technique of Patent Document 3 is to inject a low-temperature coolant into the central portion in the width direction in the rolling region of the work roll and to inject a high-temperature coolant into both ends. Due to the difference in state, there was no denying the possibility of uneven gloss in the width direction of the foil material. In addition, in order to give sufficient lubricity to the small-diameter roll, a large amount of coolant is injected to the part corresponding to the rolled material of the work roll, and even if high temperature coolant is injected, It is known from the field results that the thermal crown cannot be controlled sufficiently. In addition, when rolling the foil material (ultra-thin plate), if the contact between the upper and lower work rolls called roll kiss occurs, the deformation of the work roll is suppressed, and the flatness of the rolled plate cannot be controlled.

  Accordingly, in view of the above problems, the present invention aims to provide a shape control method that can reliably control the shape of a foil material rolled by a multi-stage rolling mill, in particular, the rolling of a foil material under a kiss rolling situation. To do.

In order to achieve the above-described object, the present invention takes the following technical means.
The shape control method in kiss rolling according to the present invention is a rolling method for rolling a foil material using a cluster type rolling mill having a work roll for rolling the rolled material, and the work roll has a diameter of the foil. When the work roll is in a kiss state, the width of the work roll is less than 0.1 times the width of the work roll, and the non-rolled portion of the work roll that is not in contact with the foil material at both ends of the work roll. Supplying a coolant having a higher temperature than the coolant supplied to the central portion of the work roll and in contact with the foil material, rolling the foil material, and controlling the rolling shape of the foil material It is characterized by.

  By using the shape control method of the present invention, shape control in foil material rolling under roll kiss rolling can be reliably performed.

It is the front view which showed the cluster type multi-high rolling mill (12 steps) typically. FIG. 2 schematically shows a state in which coolant is supplied to a work roll, (a) is a view seen from the rolling mill entry side, and (b) is a view seen from the width direction side of the rolling mill. is there. It is the figure which showed typically the condition of the edge part of the work roll supplied with a coolant. It is the figure which showed the expansion coefficient and surface temperature of the work roll (conventional rolling). It is the figure which showed the expansion coefficient and surface temperature of the work roll (rolling which concerns on this invention). It is the figure which showed distribution of the unit width load which acts on a work roll. It is the figure which showed distribution of the unit width load which acts on a work roll (enlarged view of a non-rolling part). It is the figure which showed the rolling shape of the rolling material at the time of rolling with the work roll which supplied / not supplied the high temperature coolant to the non-rolling part. It is the figure which showed the rolling shape of the rolling material at the time of rolling with the work roll which supplied / not supplied the high temperature coolant to the non-rolling part, and was the figure which showed the case where the temperature of the high temperature coolant was made variable .

Hereinafter, an embodiment of the present invention will be described based on the drawings while illustrating a cluster-type multi-high rolling mill.
In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.
FIG. 1 shows a cluster type multi-high rolling mill 1 according to the present invention, which is a 12-high rolling mill.

The cluster-type multi-stage rolling mill 1 is for rolling a rolled material 2 such as a stainless steel into a thin plate such as a foil material (for example, a thickness of 30 to 40 μm), and has work rolls 3 and 3 arranged in a pair of upper and lower sides. ing.
Each work roll 3 is a roll having a diameter of about 40 mm and smaller than that of a normal rolling mill, and the work roll diameter D / rolled material width W is about 0.1 or less.

The work roll 3 is supported by a plurality (two) of intermediate rolls 4, and the intermediate roll 4 is supported by a plurality (three) of backup rolls 5 positioned on the outermost side. In other words, as shown in FIG. 1, the intermediate roll 4 and the backup roll 5 are arranged in a fan-like manner (cluster type) like a bunch of straw around the work rolls 3 and 3.
The outermost backup roll 5 is rotatably supported by the mill housing 7 via a shaft support portion 6 incorporating a bearing or the like, and the other rolls are in an idle state. In addition, the cluster type multi-high rolling mill 1 of the present embodiment drives the intermediate roll 4 in contact with the work roll 3 with a drive motor (not shown).

A rolling material (foil material) 2 passes between the pair of work rolls 3 and 3 from the upstream side (left side in FIG. 1) to the downstream side (right side in FIG. 1) and is rolled in the thickness direction. A strip guide mechanism 8 for smoothly guiding the rolled material 2 along the rolling pass line is provided on each of the entry side and the exit side of the work roll 3.
When using such a cluster type multi-stage rolling mill 1 to roll a high-strength foil material 2 such as stainless steel, the work rolls 3 and 3 are in a roll kiss state (the work roll 3 is in contact with the non-rolled portion). Thus, it becomes difficult to perform normal crown control. In addition, since the work roll 3 has a small diameter, the amount of thermal expansion is small, and coolant control (giving a temperature distribution in the width direction of the coolant to give a difference in the amount of roll expansion in the width direction) is not suitable.

Furthermore, if the coolant control is performed with a material with severe surface gloss such as stainless steel foil, the surface properties of the foil material change at the part where the high-temperature coolant is supplied and the product cannot be used as a product. there were.
Therefore, the inventors of the present application have made extensive studies, and by injecting the high temperature coolant H to a place where the foil material 2 does not exist, the influence of the high temperature coolant H on the foil material 2 can be eliminated and the kiss load (acts on the kiss portion). It has been found that the roll reaction force can be changed. That is, if the high temperature coolant H is supplied to the place where the foil material 2 does not exist, the kiss load distribution in the non-rolled portion 3B can be changed. As a result, the bending state of the work roll 3 can be changed, and the rolled material 2 It came to the knowledge that crown control becomes possible.

  Based on such knowledge, when the foil material 2 is kiss-rolled using the cluster-type multi-high rolling mill 1, the non-rolled portion 3B of the work roll 3 that is in non-contact with the foil material 2 at both ends of the work roll 3 is used. On the other hand, the inventors have conceived a rolling method for the foil material 2 in which the foil material 2 is rolled while supplying the coolant H having a temperature higher than a predetermined temperature. By using this rolling method, the rolled shape of the foil material 2 can be reliably controlled.

Details of the “shape control method in kiss rolling” that can be employed in the cluster-type multi-high rolling mill 1 will be described below.
As shown in FIG. 2, in the cluster type multi-high rolling mill 1, a rolling portion 3 </ b> A (rolled material 2) of the work roll 3 is provided from the tip of the strip guide mechanism 8 provided on each of the entry side and the exit side of the work roll 3. Cooling coolant C (about 30 to 50 ° C. (there is a difference depending on the coolant to be used)) is jetted to cool the roll and supply lubricating oil.

Furthermore, as shown in FIGS. 2 and 3, the non-rolled portion 3 </ b> B of the work roll 3 (parts at both ends of the work roll 3 that are not in contact with the foil material 2) is compared with the cooling coolant C. Supply high temperature (+ 5 ° C or higher) coolant (high temperature coolant H).
This high-temperature coolant H is sprayed on the work roll 3 in the non-rolled portion 3B (that is, the width direction outside of the rolled material 2), and at the same time in the width direction of the rolled material 2 by a large amount of cooling coolant C supplied to the rolled portion 3A. Pushed outward. Therefore, the high temperature coolant H does not reach the foil material 2 and there is almost no influence on the surface properties of the foil material 2.

  As schematically shown in FIG. 3, roll expansion occurs in the non-rolled portion 3 </ b> B of the work roll 3 by supplying the high-temperature coolant H. In normal rolling, even if such roll expansion occurs, there is no influence on the rolling shape because it does not come into contact with the rolled material 2. However, when roll expansion occurs at a site where the ends of the work roll 3 are in contact with each other as in roll kiss rolling, the contact load at the site where the roll expansion occurs locally increases. The bending moment state with respect to the work roll 3 varies depending on the local load, and the deflection amount of the work roll 3 changes. As a result, the shape crown of the foil material 2 can be controlled.

In other words, in order to make the rolled shape of the foil material 2 a desired one, it is necessary to have a predetermined roll bending shape. For this purpose, it is necessary to change the bending force acting on the work roll 3. In order to change the bending force, high temperature coolant H may be sprayed on the non-rolled portion 3B of the work roll 3 in a kiss state.
FIG. 4 shows the thermal expansion amount and roll surface temperature of the work roll 3 in normal rolling. It can be seen that in the rolled portion, the roll temperature rises due to the heat generated by processing, and the thermal crown grows accordingly.

On the other hand, FIG. 5 shows the roll surface temperature when high temperature coolant H (+ 8 ° C. from the temperature 42 ° C. of the cooling coolant C) is injected to the non-rolled portion 3B of the work roll 3 (end portion 50 mm of the work roll 3). And thermal crown distribution. From this figure, it can be seen that the portion where the high-temperature coolant H is injected expands the roll.
Further, comparing FIG. 4 with FIG. 5, it can be seen that there is almost no change in the roll surface temperature in the rolled part, and there is no influence on the lubricity, and therefore no influence on the surface properties.

  FIG. 6 shows the surface pressure distribution of the work roll 3 under the situation of FIG. Even when the high-temperature coolant H is not injected, it can be seen that a load is generated even in the non-rolled portion 3B, and a kiss-rolled state is obtained. On the other hand, by injecting the high-temperature coolant H, the kiss load distribution changes, and it can be seen that the load also changes in the rolled portion from the change in roll deflection associated therewith.

  In FIG. 7, the surface pressure distribution (load distribution) of the non-rolling part 3B of the work roll 3 under the situation of FIG. 5 is shown. In the case without the high-temperature coolant H, there is no thermal crown in the roll kiss portion, so that the contact load is uniform from a portion slightly away from the plate end (150 mm from the center). On the other hand, when the high temperature coolant H is injected, the surface pressure in the non-rolled portion 3B is localized by the thermal crown, and a high surface pressure acts near the plate end, and the load far away from the plate end is lost. It can be seen (non-contact).

  That is, when a local surface pressure increase (change in surface pressure distribution) due to thermal expansion occurs in the non-rolled portion 3B of the work roll 3, the bending moment applied to the work roll 3 changes and the roll deflection changes. Along with this, a region where the work roll 3 does not come into contact with the end of the roll having a large thermal expansion amount occurs. In the case of a normal large-diameter roll, such a slight difference in the load (kiss load) of the non-rolled portion 3B has little influence on roll deflection deformation, but such a change is significant in a small-diameter roll.

FIG. 8 shows a change in the “outside shape of the rolled material 2” depending on the presence or absence of the high-temperature coolant H. By supplying the high-temperature coolant H to the non-rolled portion 3B of the work roll 3, the bending moment applied to the work roll 3 is changed and the deflection of the work roll 3 is changed. As a result, the end shape of the rolled material 2 is changed. You can see that
In FIG. 9, the change of the outgoing side shape of the rolling material 2 when the temperature of the high temperature coolant H is changed is shown.

  The rolling conditions in this figure are stainless steel foil with an inlet side plate thickness of 25 μm, an outlet side plate thickness of 21.5 μm, and a plate width of 300 mm. The work roll diameter is 46 mm and the roll barrel length is 600 mm. The injection position of the high-temperature coolant H in this assembling is uniformly injecting a section of 50 mm from the roll end to the roll edge from 50 mm (position 100 mm from the end of the rolled material 2).

As can be seen from FIG. 9, the bent shape of the work roll 3 can be greatly changed by supplying the high-temperature coolant H having a higher temperature to the non-rolled part 3 </ b> B of the work roll 3. Can be greatly changed.
By the way, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

For example, although this invention supplies the high temperature coolant H with respect to the non-rolling part 3B of the work roll 3, the supply form may be continuous and may be intermittent. Rolling may be performed while always injecting the high-temperature coolant H, and rolling may be performed by intermittently injecting the high-temperature coolant H as necessary.
Moreover, in this invention, the specific apparatus structure for supplying the high temperature coolant H to the non-rolling part 3B of the work roll 3 may be anything, and is not limited. An existing coolant supply means may be used for the strip guide mechanism 8 or a coolant supply nozzle may be newly provided.

1 Cluster-type multi-high rolling mill 2 Rolled material (foil material)
DESCRIPTION OF SYMBOLS 3 Work roll 3A Roll part of a work roll 3B Non-roll part of a work roll 4 Intermediate roll 5 Backup roll 6 Shaft support part 7 Mill housing 8 Strip guide apparatus H High temperature coolant C Coolant

Claims (1)

A rolling method for rolling a foil material using a cluster type rolling mill having a work roll for rolling the rolled material,
The work roll has a diameter of less than 0.1 times the plate width of the foil material,
When the work roll is in a kiss state, it is the center part of the work roll and is in contact with the foil material with respect to the non-rolled part of the work roll that is not in contact with the foil material at both ends of the work roll. A shape control method in kiss rolling, characterized in that a coolant having a temperature higher than that of a coolant supplied to a portion being supplied is supplied, a foil material is rolled, and a rolled shape of the foil material is controlled.