JP2692753B2 - Cold rolling method for metal sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold rolling having an excellent cross-sectional shape and a planar shape by so-called roll cross rolling, in which at least upper and lower work rolls are rolled in a plane parallel to the rolling surface. The present invention relates to a method for manufacturing a metal plate.

[0002]

2. Description of the Related Art In recent years, customers' requirements for the properties of sheet materials manufactured by rolling various materials (hereinafter referred to as "rolled sheet") have become more and more strict, and the sheet thickness and sheet shape are highly accurate. Control is desired.

Generally, when a metal plate is rolled, a plate thickness deviation called a plate crown occurs in the plate width direction. This plate crown occurs when the distance distribution between the upper and lower rolls during rolling (hereinafter referred to as "roll gap profile") differs in the axial direction. Therefore, a method of controlling the plate crown by changing the roll gap profile as shown in FIG. 2 (a) or (b) has been developed. For example, there are a method of attaching an initial crown to a work roll, a method of using a roll bender, a method of axially shifting an intermediate roll, and a method of using a variable crown roll. Roll cross rolling is one of them.

The roll cross rolling method is a method in which upper and lower work rolls are singly or paired with a backup roll and intersected in a plane parallel to the rolling surface to roll a metal sheet (in this specification, both are rolled). Collectively referred to as "roll cross rolling"). This method can adjust the plate crown by adjusting the cross angle (or cross angle) of the work rolls.

The reason why the plate crown can be adjusted by performing roll cross rolling will be described with reference to FIG. FIG. 1A is a plan view showing that the upper work roll 2 and the lower work roll 3 are intersected with each other in a horizontal plane at an intersection angle θ and the plate material 1 is rolled in the X direction. FIG. 1 (b) is a cross-sectional view of the central portion and the end portion taken along the line A-A. The roll cross-sectional shape was approximated by a circle.

As can be seen from FIG. 1 (b), the distance between the work rolls in the cross section in roll cross rolling is:
It is L ₁ at the center and L ₂ at the ends. At this time,
Since L ₁ <L ₂ unless θ is 0, the mechanical crown exhibits a larger distribution in the end portion than in the central portion. Further, since L ₂ can be changed by changing the size of θ, the mechanical crown can be controlled by changing θ.

In this way, the plate crown can be adjusted by controlling the mechanical crown of the roll.

However, even if the roll crown rolling can prevent the plate crown, the elongation in the longitudinal direction is different in the plate width direction, so that the rolled plate suffers from a shape defect called "ear wave" or "medium elongation". That is, when the lengthwise extension of the end portion is larger than that in the central portion, "ear waves" are generated at the end portion,
On the other hand, if the central part stretches more than the end parts,
"Medium stretch" occurs in the center.

[0009] Usually, when a metal plate is rolled, a plastic flow in the width direction is generated at the end even when a selvage wave is generated or when an intermediate elongation is generated. The reason is that there is no restraint in the width direction at the end portion, so that plastic flow easily occurs in the width direction (center portion → end portion). Therefore, as one of the means for eliminating the above-mentioned defective shape, it is conceivable to positively utilize the plastic flow in the width direction of the end portion.

It is a new knowledge which is the basis of the present invention that the defective shape can be eliminated by positively utilizing the plastic flow in the width direction of the end portion. Therefore, the reason why the defective shape can be eliminated will be described in detail in the action column.

In recent years, a rolling mill (normally called a Minimum-Edgedrop mill, which is abbreviated as ME mill) of the type in which a work roll is bent in the horizontal direction has been developed and put into practical use (Plasticity and Working, Vol. 31- 352 (1990), pages 632-638, Proceedings of the 39th Joint Symposium on Plastic Working, pages 593-596). The rolling mill is a rolling mill whose purpose is to offset a work roll with an extremely small diameter, bend it horizontally with a support roll, change the mechanical crown of the roll, and control the plate crown. It is shown in the above-mentioned document that a horizontal work roll deflection causes a frictional force in the strip width direction, and the plastic flow during rolling of the material changes in the width direction. As a result, it is suggested that by suppressing the deviation in elongation in the width direction, it is possible to change the plate thickness distribution in the width direction while maintaining the shape of the rolled material in a good condition.
The principle will be described with reference to FIG.

FIG. 3 is a plan view showing the horizontal deflection of the roll, and the arrow (→) in the drawing indicates the direction of the roll rotation vector. 3A is a diagram in which the roll is not deflected, FIG. 3B is a state in which the roll is deflected in the rolling direction, and FIG. 3C is a diagram in which the roll is deflected in the rolling direction. in this way,
As shown in Fig. 3 (b) or (c), the roll direction vector is inward or outward, respectively, compared to normal rolling, and the velocity vector in the strip width direction is different, so friction in the strip width direction A force is generated, causing plastic flow of the material.
However, this method requires a special roll arrangement and large-scale auxiliary equipment for bending the roll, and
It is difficult to control the roll deflection amount, and it is also difficult to increase the roll deflection amount. Therefore, it is extremely difficult to arbitrarily control the plastic flow of the material in the plate width direction.

[0013]

The roll-cross cold rolling method for controlling the strip crown has a problem in that, as described above, a shape defect called middle elongation or a selvage wave occurs.

An object of the present invention is to prevent the occurrence of defective shapes by a relatively simple method in roll cross rolling for controlling the strip crown.

[0015]

Means for Solving the Problem In the roll cross rolling, the present inventor changed the friction coefficient in the axial direction of the work roll to exert a shearing force in the plate width direction of the metal plate, thereby causing the material to move in the plate width direction. It was found that the plate thickness can be made uniform without causing plastic flow of No. 3 and causing no defective shape. That is, the gist of the present invention is "a method of cold rolling a metal plate, characterized in that the friction coefficient between a work roll and a metal plate is changed in the axial direction of the work roll to perform roll cross rolling". is there.

[0016]

The function of causing plastic flow of the material in the plate width direction will be described.

FIG. 4 shows a case where roll cross rolling is performed at a cross angle θ without changing the friction coefficient between the upper work roll and the upper surface of the metal plate and between the lower work roll and the lower surface of the metal plate in the axial direction of the work roll. 2 shows the relationship between the metal plate and the upper and lower work rolls. 4 (a) is a plan view and FIG.
(b) is a sectional view of the direction of the shearing force acting on the upper and lower surfaces of the metal plate as seen from the rolling direction entry side. However, in FIG. 5 and (b) of FIGS. 6 to 8 to be described later, the plate thickness direction is shown in an enlarged manner compared to the plate width direction.

As shown in FIG. 4 (a), there is a deviation of an angle θ between the velocity vector in the roll rotation direction and the velocity vector in the rolling direction. Relative slip occurs. As a result, the shearing force F ₁ acting from the end A to the end C acts on the upper surface of the metal plate, and the shearing force F ₂ acting from the end C to the end A acts on the lower surface of the metal plate. Become. At this time, if the coefficient of friction between the work roll and the metal plate is substantially the same both in the upper and lower surfaces of the metal plate and in the plate width direction of the metal plate, the magnitudes of the shearing force F ₁ and the shearing force F ₂ are set to the plate width. When viewed in the direction, the distribution is as shown in Fig. 4 (b).

That is, F ₁₁ = F ₁₂ = F ₁₃ , and F ₂₁
= F ₂₂ = F ₂₃ , and F ₁₁ = F ₂₁ , F ₁₂ = F ₂₂ , F
₁₃ = F ₂₃ . Therefore, the forces in the plate width direction on the upper and lower surfaces of the metal plate cancel each other out. That is, at the end portions A and B of the metal plate, plastic flow in the plate width direction due to the absence of the restraining force only occurs to a normal extent.

FIG. 5 shows an example of a roll whose surface roughness is changed in the width direction, and FIGS. 6, 7 and 8 show the upper work roll and the upper surface of the metal plate using a roll as shown in FIG. And the friction coefficient between the lower work roll and the lower surface of the metal plate in the axial direction of the work roll to perform roll cross rolling at a cross angle θ, which is an example showing the relationship between the metal plate and the upper and lower work rolls. 6 to 8A are plan views, and FIGS. 6 to 8B are cross-sectional views in which the direction of the shearing force acting on the upper and lower surfaces of the metal plate is viewed from the rolling direction entry side.

FIGS. 6 to 8 show a method of changing the surface roughness of the work roll in the axial direction of the work roll to change the friction coefficient between the upper work roll and the lower surface of the metal plate in the axial direction of the work roll. ing.

In the method shown in FIG. 6, the size of the cross angle θ and the cross direction are the same as those in FIG. 4, the surface roughness on the end A side of the upper work roll is large, and the surface roughness on the end C side of the upper work roll is large. The surface roughness on the edge A side of the lower work roll is as small as the surface roughness on the edge C side of the upper work roll, and the surface roughness on the edge C side of the lower work roll is small. The friction coefficient between the upper work roll and the upper surface of the metal plate and between the lower work roll and the lower surface of the metal plate is changed in the axial direction of the work roll by increasing the surface roughness on the end A side of the upper work roll to the same degree. I am letting you.

Also in FIG. 6 (a), as in the case shown in FIG. 4 (a), a shearing force F ₁ acting from the end A to the end C acts on the upper surface of the metal plate, and the lower surface of the metal plate. A shearing force F ₂ acting from the end portion C toward the end portion A acts on this. However, the coefficient of friction between the work roll and the metal plate is changed in the plate width direction of the metal plate so that the friction coefficient between the work roll and the metal plate shows opposite tendencies in the plate width direction on the upper surface and the lower surface of the metal plate. Therefore, when the magnitudes of the shearing force F ₁ and the shearing force F ₂ are viewed in the plate width direction, the distributions are as shown in FIG. 5 (b). That is, F ₁₁ <F ₁₂ <F ₁₃ , F ₂₁ > F ₂₂ > F ₂₃ , and F ₁₁ <F ₂₁ , F ₁₂ = F ₂₂ , and F ₁₃ > F ₂₃ .
Therefore, due to the relative relationship of the forces of the upper and lower surfaces of the plate, an inward force acts on both the end portion A and the end portion C. It is possible to generate a large inward plastic flow.

In the method shown in FIG. 7, the size of the cross angle θ and the cross direction are the same as those in FIG. 4, the surface roughness on the end A side of the upper work roll is small, and the surface roughness on the end C side of the upper work roll is small. The surface roughness on the edge A side of the lower work roll is as large as the surface roughness on the edge C side of the upper work roll, and the surface roughness on the edge C side of the lower work roll is large. By reducing the surface roughness on the end A side of the upper work roll to the same extent, the coefficient of friction between the upper work roll and the upper surface of the metal plate and between the lower work roll and the lower surface of the metal plate is changed in the axial direction of the work roll. I am letting you. That is, the magnitude of the surface roughness in the axial direction of the work roll is reversed from that in the method shown in FIG.

Also in FIG. 7 (a), as in the case shown in FIG. 4 (a), a shearing force F ₁ acting from the end A to the end C acts on the upper surface of the metal plate, and the lower surface of the metal plate. A shearing force F ₂ acting from the end portion C toward the end portion A acts on this. However, the coefficient of friction between the work roll and the metal plate is changed in the plate width direction of the metal plate so that the friction coefficient between the work roll and the metal plate shows opposite tendencies in the plate width direction on the upper surface and the lower surface of the metal plate. Therefore, when the magnitudes of the shearing force F ₁ and the shearing force F ₂ are viewed in the plate width direction, the distributions are as shown in FIG. 7 (b). That is, F ₁₁ > F ₁₂ > F ₁₃ , F ₂₁ <F ₂₂ <F ₂₃ , and F ₁₁ > F ₂₁ , F ₁₂ = F ₂₂ , and F ₁₃ <F ₂₃ .
Therefore, due to the relative relationship of the forces of the upper and lower surfaces of the plate, outward force acts on both the end portion A and the end portion C, so that the end portions A and C of the metal plate have a plate width direction. A large outward plastic flow can be generated.

In the method shown in FIG. 8, only the cross direction is shown in FIG.
The method is the same as the method shown in FIG. 6 and the other conditions are exactly the same as the method shown in FIG.

In FIG. 8 (a), unlike the case shown in FIG. 6 (a), a shearing force F ₁ acting from the end portion C to the end portion A acts on the upper surface of the metal plate, and the lower end of the metal plate is attached. A shearing force F ₂ acting from the portion A toward the end portion C acts. Furthermore, when the magnitudes of the shearing force F ₁ and the shearing force F ₂ are viewed in the plate width direction, the distributions are as shown in FIG. 8 (b). That is, F ₁₁ <F ₁₂ <F ₁₃ , F ₂₁ > F ₂₂ > F ₂₃ , and F ₁₁ <F ₂₁ , F ₁₂
= F ₂₂ , F ₁₃ > F ₂₃ . Therefore, due to the relative relationship of the forces of the upper and lower surfaces of the plate, outward force acts on both the end portion A and the end portion C, so that the end portions A and C of the metal plate have a plate width direction. A large outward plastic flow can be generated.

As described above, in roll cross rolling as shown in FIG. 4, a method of producing a large plastic flow inward in the sheet width direction at the end portions A and C of the metal sheet is as follows:
There is a method as shown in FIG. On the contrary, a method as shown in FIG. 7 is used to generate a large plastic flow outward in the plate width direction at the ends A and C of the metal plate, that is,
There is a method of reversing the friction coefficient between the work roll and the metal plate as shown in FIG. 6, or a method as shown in FIG. 8, that is, a method of reversing the cross direction as shown in FIG.

Next, a large outward or inward plastic flow in the sheet width direction generated at the ends A and C of the metal plate causes a shape defect called "ear wave" or "medium elongation" generated in the metal plate by roll cross rolling. The reason why can be prevented is explained.

The ear wave or the middle extension is caused by the difference in the extension in the longitudinal direction in the plate width direction. Therefore, if the elongation in the longitudinal direction approaches a uniform state in the plate width direction,
It can reduce or even prevent ear waves or mid-stretch.

According to the present invention, the large plastic flow in the plate width direction at the end portion of the metal plate generated by the above-described method is suppressed or promoted in the longitudinal extension at the end portion of the metal plate. It is used for. By doing so, it is possible to perform rolling so that the elongation in the longitudinal direction becomes equal to that in the strip width direction, and as a result, it is possible to mitigate or even prevent selvage or middle elongation.

First, when an ear wave is generated, it is sufficient to suppress the elongation in the longitudinal direction at the end portion of the metal plate as much as possible.
For that purpose, a large outward plastic flow in the width direction of the metal plate may be generated. When a large outward plastic flow is generated in the plate width direction at the end of the metal plate, elongation in the longitudinal direction at the end of the metal plate can be suppressed during rolling, and as a result, the degree of occurrence of the ear wave is reduced. Can be controlled.

Next, when intermediate elongation occurs, it is sufficient to promote elongation in the longitudinal direction at the end portion of the metal plate as much as possible. For that purpose, a large inward plastic flow in the plate width direction at the end portion of the metal plate. It should be generated. Generating a large inward plastic flow in the width direction at the edge of the metal plate can promote longitudinal elongation at the edge of the metal plate during rolling, thus controlling the occurrence of medium elongation. can do.

In order to cause the inward or outward plastic flow in the plate width direction, the method of the present invention "changes the coefficient of friction between the work roll and the metal plate in the axial direction of the work roll". This means is adopted. As a method of changing the friction coefficient between the work roll and the metal plate in the roll axial direction, the temperature of the roll is changed in the axial direction,
Any method such as changing the temperature of the metal plate in the plate width direction may be used, but it is not necessary to introduce large-scale new equipment and to consider the effect of thermal expansion of the metal plate or roll. Considering this, the types, temperatures, and concentrations of rolling oil that must be used in cold rolling operations are
It is preferable to change at least one of the viscosity, the emulsion particle size and the supply amount, and the surface roughness of the work roll itself in the roll axial direction.

9 (a) to 9 (e) show the results of the test conducted under the following conditions.

The surface roughness R _a is uniform in the axial direction and is 1.0 μm.
m, 0.3 μm and 0.03 μm, three types of work rolls are used for cold rolling by parallel rolling (rolling in which the upper and lower work rolls do not intersect in the horizontal plane), and the rolling oil supply conditions and the work roll surface roughness , The correlation between the friction coefficient between the metal plate and the roll was obtained. Rolling oil temperature is 20
~ 85 ℃, concentration 0.5 ~ 15%, viscosity 10 ~ 300cSt / 40 ℃,
Emulsion particle size is the average particle size consisting of the median of the distribution 1
.About.15 .mu.m, and the supply rate was changed within the range of 3-300 liters / min. At this time, the work roll diameter is 300 m
m, the rolling reduction was 30%, and the rolling speed was 450 m / min.
9 (a) to 9 (e) are test results in parallel rolling, but these results are also applicable to roll cross rolling.

Correlations among the temperature, concentration, viscosity, emulsion particle size and supply amount of rolling oil and the friction coefficient between the metal plate and the roll are shown in FIGS. 9 (a) to 9 (e). Each figure shows three levels of surface roughness of the work roll (large surface roughness: _Ra = 1.0 μm, medium surface roughness: _Ra = 0.3 μm).
m, surface roughness is small: _Ra = 0.03 μm) and the results of rolling are shown. Therefore, the correlation between the surface roughness of the work roll and the friction coefficient between the metal plate and the roll is also shown. become.

For example, it can be seen from FIG. 9 (a) that the coefficient of friction increases as the temperature of the rolling oil increases. Therefore, when the work rolls are arranged and the roll cross rolling is performed as shown in FIG. 1, the rolling oil having a temperature higher than that of the C side is supplied to the end portion A side of the upper surface and the opposite is applied to the lower surface. If rolled under the conditions, an inward force acts on the rolled material in the sheet width direction, and it is possible to reduce the occurrence of sheet crown while relaxing the intermediate elongation.

As can be seen from FIGS. 9 (a) to 9 (e), in order to increase the friction coefficient, when the surface roughness of the work roll is kept constant, the temperature of the rolling oil is increased, the concentration is decreased, and the viscosity is increased. Or at least one of the operations of decreasing the emulsion particle size or decreasing the supply amount. Further, if the various conditions of the rolling oil are kept constant, the surface roughness of the work roll may be increased.
By performing this in the roll axis direction of roll cross rolling, it is possible to reduce the plate crown and to manufacture a rolled plate having no defective shape. That is, if roll cross rolling is performed by changing an appropriate factor in the axial direction, a large plastic flow occurs in the plate width direction at the end portion of the metal plate, so that the defective shape can be prevented.

In the roll cross cold rolling method of the present invention, in roll cross rolling, the surface roughness of the work roll or the supply conditions of the rolling oil is changed in the axial direction of the work roll, and the roll between the roll and the metal plate is changed. The rolling is performed by changing the friction coefficient in the axial direction, and is not limited by the material of the metal plate to be rolled, the material of the work roll, the type of rolling oil, or the like. When the coefficient of friction is changed in the axial direction, it may be changed gradually, or may be changed regionally so as to have one or more displacement points at the plate central portion or other places.

The effects of the present invention will be described below based on examples.

[0042]

Example 1 Roll cross cold rolling was performed by changing the friction coefficient between the roll and the metal plate in the axial direction of the work roll.

Using the same rolling oil as that used in the above test, ordinary steel having a plate thickness of 2.0 mm and a width of 1000 mm was used in Tables 1-1 and 1.
Rolling was performed by a 4Hi rolling machine (pair cross mill) with a work roll diameter of 400 mm at a rolling reduction of 30% based on the rolling conditions shown in -2. In the cross angles of the work rolls in Table 1, positive angles represent the same cross arrangement as in FIG.

FIG. 10 is a view showing that the rolling oil supply nozzle is divided into five in the plate width direction on both the upper surface and the lower surface of the plate material. The rolling oil supply nozzle is divided into 5 parts at a pitch of 200 mm in the plate width direction, and the divided supply nozzle nozzle numbers are 1, 2, 3, 4, 5 from the end A side of the upper surface of the plate, and end A of the lower surface of the plate.
It was 6, 7, 8, 9, 10 from the side. Nozzle Nos. 3 and 5 at the central portion B and edge C of the plate material are 8 and 10, respectively.
It is. From each supply nozzle, rolling oil having the temperature, concentration, viscosity, emulsion particle size and supply amount shown in Table 1-1 and Table 1-2 was supplied. The viscosity of rolling oil is the value when the temperature is 40 ° C. When the total supply amount is 200 liters / min, the supply amount per supply nozzle is 20 liters / m.
in.

FIG. 11 is a view for explaining that the surface roughness of the work roll is changed in the axial direction of the work roll in correspondence with the nozzle numbers 1 to 10 of the divided supply nozzles.

In the comparative example of Test No. 1, the temperature, concentration, viscosity, emulsion particle size and supply amount of rolling oil, and the surface roughness of the work roll were all constant in the work roll axial direction and on the front and back sides of the metal plate. Then, an example in which roll cross rolling is performed in a state where the friction coefficient is constant in the axial direction of the work roll is shown. At this time, the rolled plate had an intermediate elongation.

Test Nos. 2 to 9 are examples of the present invention. In roll cross rolling, at least one or more of the temperature, concentration, viscosity, emulsion particle size and supply amount of the rolling oil, and the surface roughness of the work roll are changed in the work roll axial direction and the front side and the back side of the metal plate. This is the case. Test No. 2 is the viscosity of rolling oil, Test No. 3 is the temperature of rolling oil, Test No. 4 is the concentration of rolling oil, Test No. 5 is the emulsion particle size of rolling oil, and the test is
No. 6 is the supply amount of rolling oil, Test No. 7 is the temperature and concentration of the rolling oil and the supply amount, Test No. 8 is the surface roughness of the work roll, and Test No. 9 is the surface roughness of the work roll and the rolling oil. This is the case when the respective concentrations of are changed. In all the tests of the examples of the present invention, the roll was arranged so that an inward force was generated, and the same roll cross angle as in FIG. 1 was set to be positive. That is, test No. 2 ~
In Fig. 7, the roll arrangement in Fig. 1 was used, and in Test Nos. 8 to 9, the roll arrangement was symmetrical to that in Fig. 1 in the plate width direction.

The drawing difference between the center of the rolled plate and the position 5 mm from the end of the rolled plate was measured and converted into a steepness, which is shown in FIG. A negative value indicates that the surface shape of the rolled plate is a medium stretched shape. As can be seen from this figure, the rolled sheet rolled in the example of the present invention has a moderately stretched shape and shows a good shape as compared with the rolled sheet having a uniform friction coefficient in the width direction of the comparative example.

[0049]

[Table 1-1]

[0050]

[Table 1-2]

[0051]

Example 2 The same materials as in Example 1 were used, and the results in Table 2-
Under the condition that only the surface roughness of No. 8 roll No. 2 is changed in the axial direction, the cross angle of the work roll is changed from -1.0 ° to 1.0 °.
The roll cross rolling was performed by changing the temperature. Further, as a comparative example, rolling was similarly performed using a work roll having a constant surface roughness. At this time, the reduction rate was changed to two types of 20% and 30% in both the present invention example and the comparative example.

FIG. 13 shows the relationship between the cross angle of the work roll and the steepness obtained by converting from the difference in elongation between the position 5 mm from the plate edge and the center at this time. As in Example 1,
The steepness is negative when the shape is a middle stretch, and the steepness is positive when the shape is an ear wave. Regarding the cross angle, the case of roll arrangement as shown in FIG. 6 is represented by a positive sign, and the case of roll arrangement as shown in FIG. 8 is represented by a negative sign.

As can be seen from FIG. 13, in the work roll arrangement in which the cross angle is positive, when the steepness is negative, that is, when the medium elongation occurs, the method of the present invention (marked with ● and ○ in the figure) is used. The absolute value is small and the medium stretched shape is improved. On the other hand, in the work roll arrangement in which the cross angle is negative, the steepness is positive, that is, when the ear wave is generated, the ear wave shape is improved by using the method of the present invention (● mark and ○ mark in the figure). It

Regarding the plate crown control, the direction of the roll cross (positive or negative) is irrelevant, and only the absolute value of the cross angle of the roll has an effect, so that the roll can be changed depending on the shape of the material (medium extension, seismic wave). The plate shape can be improved by setting the cross direction. The present invention is characterized in that the plate crown and the plate shape can be controlled simultaneously, and while controlling the plate crown by the cross angle of the work roll, the temperature, concentration, viscosity, emulsion particle size and supply amount of the rolling oil and the work roll By adjusting the axial distribution of surface roughness, etc., the coefficient of friction between the work roll and the metal plate during rolling is changed in the axial direction of the work roll to control the plate shape, and the optimum plate crown and plate shape are obtained. It is possible to obtain.

[0055]

According to the method of the present invention, in roll cross rolling having an excellent effect on the control of the plate crown,
It is possible to eliminate shape defects such as middle stretch and ear waves that occur with the crown control. Therefore, the metal plate manufactured by the method of the present invention has a uniform thickness in the width direction and is of high quality having an excellent planar shape. This method can be carried out by changing the rolling oil conditions and roll roughness among the basic operating conditions of roll cross rolling.
It has the advantage of not requiring large-scale equipment such as a mill.

[Brief description of the drawings]

FIG. 1 (a) is a plan view showing upper and lower work rolls intersecting each other in a horizontal plane at a crossing angle 2θ, and FIG. 1 (b) is a sectional view in the rolling direction at the central portion and the end portions thereof. It is a figure.

FIG. 2 is a diagram showing a roll gap profile during rolling.

FIG. 3 is a plan view of a roll when it is bent in a horizontal direction and rolled, and an arrow indicates a direction of a rotation vector of the roll.

FIG. 4 shows a relationship between a rolled material and upper and lower work rolls in roll cross rolling. (a) is a plan view seen from the upper side, and (b) is a sectional view of the rolled material seen from the entrance side. F ₁ and F ₂ in the figure represent shearing forces in the plate width direction.

FIG. 5 shows an example of a work roll whose surface roughness is changed in the width direction.

FIG. 6 shows an example in which roll cross rolling is performed by changing the friction coefficient in the axial direction, and shows the relationship between the rolled material and the upper and lower work rolls. (a) is a plan view showing a state in which rolls whose surface roughness is changed in the axial direction are arranged upside down and roll cross rolling is performed, and (b) is a cross-sectional view of the rolled material as seen from the entrance side. is there.

FIG. 7 shows an example of performing roll cross rolling by changing the friction coefficient so that a force acts in the direction opposite to that in FIG.

FIG. 8 shows an example in which roll cross rolling is performed by changing the cross direction so that a force acts in the direction opposite to that in FIG.

FIG. 9 (a) shows the correlation between the friction coefficient between the metal plate and the roll and the temperature of the rolling oil.

FIG. 9 (b) shows the correlation between the friction coefficient between the metal plate and the roll and the concentration of rolling oil.

FIG. 9 (c) shows the correlation between the friction coefficient between the metal plate and the roll and the viscosity of the rolling oil.

FIG. 9 (d) shows the correlation between the friction coefficient between the metal plate and the roll and the emulsion particle size of the rolling oil.

FIG. 9 (e) shows the correlation between the friction coefficient between the metal plate and the roll and the supply amount of rolling oil.

FIG. 10 is a view for explaining that the rolling oil supply nozzle is divided into five in the plate width direction.

FIG. 11 is a diagram illustrating that the surface roughness of the work roll is changed in the work roll axial direction in association with the nozzle numbers of the divided supply nozzles.

FIG. 12 is a graph showing the steepness for each test No., which is obtained by converting the drawing difference between the central portion and the position 5 mm from the end of the rolled plate.

FIG. 13 is a graph showing the correlation between the steepness and the work roll cross angle, which are obtained by converting the drawing difference between the position 5 mm from the end of the rolled material and the center.

Front page continuation (72) Inventor Masahiro Matsuura 4-53-3 Kitahama, Chuo-ku, Osaka City, Osaka Prefecture Sumitomo Metal Industries, Ltd. (72) Inventor Tetsuo Kajiwara, 4-22, Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture No. Mitsubishi Heavy Industries, Ltd. Hiroshima Research Institute (72) Inventor Kazuo Morimoto 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture No. 22 Mitsubishi Heavy Industries Ltd. Hiroshima Research Institute (72) Inventor Masashi Matsumoto 5, Fukahori-cho, Nagasaki-shi, Nagasaki Prefecture No. 717-1 Sanryo Heavy Industries Co., Ltd. Nagasaki Research Institute (56) Reference JP-A-55-36041 (JP, A)

Claims (1)

(57) [Claims] 1. A method for cold rolling a metal sheet, which comprises performing roll cross rolling by changing a coefficient of friction between the work roll and the metal sheet in an axial direction of the work roll.