JP2824163B2 - Roll cross cold rolling method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention improves the appearance quality of a rolled plate (hereinafter referred to as a "rolled plate") when upper and lower work rolls are crossed in a horizontal plane to cold-roll the plate. More particularly, the present invention relates to a roll cloth cold rolling method for obtaining uniform luster in the width direction of a rolled plate.

[0002]

2. Description of the Related Art In recent years, demands on the surface properties of rolled plates of various materials including stainless steel plates have become more and more demanding by consumers, and in particular, it has been strongly desired to make the gloss of rolled plates uniform.

On the other hand, in order to control the crown of a rolled plate, the upper and lower work rolls are independently crossed in a horizontal plane,
A method of rolling a plate (this is referred to as "work roll cross rolling") or crossing in a horizontal plane by pairing with a backup roll and rolling the plate (this is referred to as "pair cross rolling") has been adopted. I have. These cross-rolling methods have already been put to practical use in hot rolling,
Since cold rolling causes uneven gloss in the width direction of the rolled sheet, improvement is required in order to apply it to cold rolling which requires high appearance quality.

[0004] The reason why roll-cross rolling causes uneven gloss in the width direction of a rolled plate is described with reference to Figs.
This will be described below. FIG. 1 is a plan view showing that an upper work roll 2 and a lower work roll 3 intersect with each other in a horizontal plane at an intersection angle α, and the plate 1 is rolled in the X direction. 2 (a), 2 (b) and 2 (c) are cross-sectional views of FIG. 1 and show the bite angle θ ₁ into the upper work roll at the end A, the center B and the end C of the plate material, respectively. shows the biting change of angle θ ₂ of the lower work roll. The biting angle at the end A of the plate is θ ₁ > θ ₂ , and the biting angle at the center B is θ
₁ = θ ₂ , and the bite angle at the end C is θ ₁ <θ ₂ .
FIG. 3 shows that the glossiness of the rolled plate changes in the width direction of the rolled plate and that the upper surface and the lower surface of the rolled plate are different. When the biting angle of the plate material into the work roll changes in the plate width direction, the amount of the supplied rolling oil introduced into the roll bite varies in the plate width direction. Therefore, as shown in FIG. Change in direction. As a result, unevenness in gloss occurs in the rolled plate in the width direction of the rolled plate, and the appearance quality of the rolled plate as a whole deteriorates.

Japanese Patent Application Laid-Open No. Sho 57-14404 discloses that a sheet material enters between work rolls at the entrance, exit or both sides of a rolling mill according to the crossing angle of a work roll and the exit thickness of a rolled plate. A rolling method for controlling the corners in the width direction is disclosed. By controlling the entry angle in the sheet width direction, the bite angle of the sheet material into the work roll is made constant in the sheet width direction, and the amount of rolling oil introduced into the roll bite is made uniform over the entire area in the sheet width direction. It is assumed that.

[0006] In this method, the approach angle of the sheet material is controlled in the sheet width direction. Therefore, rolls for this purpose need to be installed on the entrance side and the exit side of the rolling mill. Therefore, there is a problem of an installation space and a problem that an equipment cost increases. Moreover, it is technically difficult to adjust the approach angle of the sheet material in the sheet width direction according to the operating conditions. In addition, when the method of adjusting the entry angle of the sheet material is applied to a cold tandem rolling mill, the rolls for adjusting the entry angle are installed on the entrance side and the exit side of each rolling mill, so that the line becomes long, and the sheet material is further twisted while being twisted. There is also a problem that the pass line of the passing plate is not horizontal because the plates are passed, and the passing plate facility becomes extremely complicated.

[0007]

The roll cloth rolling for controlling the crown of the roll has a problem that uneven gloss occurs in the width direction of the rolled plate as described above. On the other hand, consumer demands for the surface properties of rolled sheets are becoming more and more severe. The rolling method disclosed in JP-A-57-14404 requires a large installation space, and the rolling line is complicated and long. Equipment costs also increase.

[0008] An object of the present invention is to provide a rolled plate having a uniform appearance in the width direction of a rolled plate in a relatively simple manner when cold rolling a plate by crossing the upper and lower work rolls in a horizontal plane. It is to produce a good rolled plate.

[0009]

According to the present invention, there is provided a method for cold rolling a sheet material by intersecting upper and lower work rolls in a horizontal plane, wherein the temperature, concentration, viscosity, emulsion particle size and supply amount of rolling oil, The roll cross cold rolling method for changing at least one of the surface roughness of the work roll in the axial direction of the work roll ”is to be summarized.

The specific procedure for applying the method of the present invention to actual rolling is as follows. 1) Select the rolling oil to be used for the rolling mill.

2) The surface roughness of the work roll used in the rolling mill is made constant.

3) Roll cross rolling is performed by changing only the temperature of the rolling oil, and the correlation between the glossiness of the rolled sheet and the temperature of the rolling oil is determined in advance.

4) Roll cross rolling is performed by changing only the concentration of the rolling oil, and a correlation between the glossiness of the rolled sheet and the concentration of the rolling oil is obtained in advance.

5) Roll cross rolling is performed by changing only the viscosity of the rolling oil, and the correlation between the glossiness of the rolled sheet and the viscosity of the rolling oil is determined in advance.

6) Roll cross rolling is performed by changing only the emulsion particle size of the rolling oil, and the correlation between the glossiness of the rolled plate and the emulsion particle size of the rolling oil is determined in advance.

7) Roll cross rolling is performed by changing only the supply amount of the rolling oil, and the correlation between the glossiness of the rolled sheet and the supply amount of the rolling oil is obtained in advance.

8) The surface roughness of the work roll used in the rolling mill is changed in several steps, and the above 3) to 7) are repeated.

9) When a plurality of rolling oils are used for the rolling mill, the above 2) to 8) are repeated for each rolling oil.

10) As described above, based on the procedures 1) to 9), the correlation between the glossiness of the rolled sheet and the temperature, concentration, viscosity, emulsion particle size, supply amount, and work roll surface roughness of the rolling oil is previously determined. .

11) In actual operation, roll cross rolling is performed while keeping the temperature, concentration, viscosity, emulsion particle size, supply amount, and surface roughness of the work roll constant in the axial direction of the work roll. It is checked how much the glossiness of the rolled plate at that time changes in the work roll axis direction.

12) After confirming nonuniformity of the glossiness of the rolled plate in the same manner as in the above 11), in order to make the glossiness in the axial direction of the work roll constant, based on the correlation of the above 10) obtained in advance. One or more of the temperature, concentration, viscosity, emulsion particle size, supply amount, and work roll surface roughness of the rolling oil are changed in the work roll axis direction.

[0022]

[Action] The glossiness of the rolled sheet and the temperature, concentration, viscosity,
FIG. 4 shows the correlation between the emulsion particle size and the supply amount.
(a), FIG. 4 (b), FIG. 4 (c), FIG. 4 (d) and FIG. 4 (e). These figures show the glossiness and rolling oil specifications when the sheet material is cold-rolled without crossing the upper and lower work rolls in a horizontal plane (that is, by so-called parallel rolling with an intersection angle α = 0). Is a qualitative correlation. Each figure shows the surface roughness of the work roll in three stages (large surface roughness: _Ra =
1.0 µm, medium surface roughness: _Ra = 0.3 µm, surface roughness small: _Ra = 0.03 µm). This also indicates a correlation with the roughness.

The gloss was measured by using a gloss meter at an incident angle of 20 ° in the width direction of the rolled sheet.

On the other hand, the temperature of the rolling oil is 20 to 85 ° C. and the concentration is
0.5 to 15%, viscosity was 10 to 300 cst / 40 ° C, emulsion particle size was 1 to 15 µm, average particle size consisting of median of distribution, and supply amount was 3 to 300 l / min.

For example, FIG. 4A shows that when the surface roughness of the work roll is small, the glossiness of the rolled plate increases as the temperature of the rolling oil increases, and when the surface roughness is medium, the temperature increases. The glossiness increases as the temperature increases, but the glossiness decreases when the temperature rises above a certain temperature, and the glossiness changes even when the temperature is increased within a low temperature range when the surface roughness is large. None, but above a certain temperature the gloss decreases.

As shown in FIG. 3 described above, on the upper surface of the rolled plate, the gloss at the end A is lower than that at the end C, and at the lower surface of the rolled plate, the end C is closer to the end A. Lower gloss. Therefore, for example, in the case of roll cross rolling using a work roll having a small surface roughness, a rolling oil having a higher temperature than the end C side is supplied to the end A side of the upper surface of the plate material, and the lower surface of the plate material is If a rolling oil having a higher temperature than the end A is supplied to the end C, the glossiness is uniform and good over the entire upper and lower surfaces of the rolled plate.

Each of the concentration, viscosity, emulsion particle size, and supply amount of the rolling oil changes in the width direction of the plate material, that is, in the work roll axis direction, on each of the upper surface and the lower surface of the plate material, similarly to the aforementioned temperature. When the rolling oil is supplied, the glossiness can be made uniform and favorable over the entire upper and lower surfaces of the rolled plate. Hereinafter, FIGS. 4 (b) and 4
Only the experimental results of (c), FIGS. 4 (d) and 4 (e) will be described.

FIG. 4B shows that when the surface roughness of the work roll is small, the glossiness of the rolled sheet decreases as the concentration of the rolling oil increases, but the glossiness is constant even when the concentration is higher than a certain level. When the surface roughness is medium, the glossiness increases as the density is increased in the low density range, but when the density is higher than a certain density, the glossiness conversely decreases. When the glossiness is constant and the surface roughness is large, the glossiness increases as the density increases, but the glossiness is constant even when the density is higher than a certain value.

FIG. 4C shows that when the surface roughness of the work roll is small, the glossiness of the rolled plate decreases as the viscosity of the rolling oil increases, and when the surface roughness is medium, the viscosity is low. The higher the viscosity within the range, the higher the gloss, but the higher the viscosity, the lower the gloss.On the other hand, if the surface roughness is large, the higher the viscosity, the higher the gloss. It shows that the glossiness becomes constant even if it is higher.

As a method of changing the viscosity of the rolling oil, there is a method of adjusting the viscosity of a base oil, such as a mineral oil, a fat or a synthetic ester, or a method of increasing or decreasing the amount of a high-molecular polymer among additives.

FIG. 4D shows that when the surface roughness of the work roll is small, the glossiness of the rolled sheet decreases as the emulsion particle size of the rolling oil increases, but even if the emulsion particle size is larger than a certain emulsion particle size. The glossiness is constant, and when the surface roughness is medium, the glossiness increases as the emulsion particle size increases within the range where the emulsion particle size is small. The gloss becomes constant even if the emulsion particle size is subsequently increased, and when the surface roughness is large, the gloss increases as the emulsion particle size increases, but the gloss increases when the emulsion particle size increases. This also indicates that the glossiness is constant.

FIG. 4 (e) shows that when the surface roughness of the work roll is small, the glossiness of the rolled plate decreases as the supply amount of the rolling oil increases, but the glossiness increases even when the supply amount exceeds a certain value. When the surface roughness is medium and the surface roughness is medium, the glossiness increases as the supply amount increases in the range where the supply amount is small. When the surface roughness is large and the surface roughness is large, the gloss increases as the supply amount increases, but the gloss level remains constant even when the supply amount exceeds a certain value. Is shown.

Although the above experimental results are for parallel rolling, the same technique can be applied to roll cross rolling. That is, if 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 axis direction and roll cross rolling is performed, the gloss of the rolled plate is increased. The degree of unevenness can be prevented. As a result, a rolled plate having uniform and good gloss can be manufactured.

[0034]

EXAMPLE A hot-rolled material (pickled) having a thickness of 3.0 mm, a width of 1000 mm and a material of JIS-SUS430 was subjected to a cold rolling pass schedule shown in Table 1 and rolling conditions shown in Tables 2-1 and 2-2. And rolled with a 4Hi rolling mill having a work roll diameter of 400 mm.

FIG. 5 is a view showing that the supply nozzle of the rolling oil is divided into five parts in the width direction of the plate on both the upper surface and the lower surface of the plate material. Rolling oil supply nozzles at 200mm pitch in the plate width direction 5
The nozzle numbers of the divided supply nozzles were 1, 2, 3, 4, 5 from the end A side of the upper surface of the plate material and 6, 7, 8, 9, 10 from the end A side of the lower surface of the plate material. Central part B on the upper surface of the plate material,
The nozzle numbers at the end C are 3 and 5, respectively, and the nozzle numbers at the center B and the end C on the lower surface of the plate are 8 and 10, respectively. From each supply nozzle, the rolling oil of the temperature, concentration, viscosity, emulsion particle size and supply amount shown in Table 2-1 and Table 2-2 was supplied. The viscosity of the rolling oil is a numerical value when the temperature is 40 ° C., and when the supply amount is indicated as 200 l / min as a whole, the supply amount per supply nozzle is 20 l / min.

FIG. 6 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 nozzles Nos. 1 to 10 of the divided supply nozzles.

Test Nos. 1 to 8 are examples of the present invention. In roll cross rolling, when 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 plate material. It is. Test No. 1 was the viscosity of the rolling oil, Test No. 2 was the temperature of the rolling oil, Test No. 3 was the concentration of the rolling oil, Test No. 4 was the emulsion particle size of the rolling oil, Test N
o.5 is the supply amount of rolling oil, Test No. 6 is the temperature, concentration and supply amount of rolling oil, Test No. 7 is the work roll surface roughness, Test No. 8 is the work roll surface roughness and rolling oil Are changed respectively.

Test Nos. 9 and 10 are comparative examples. Test No. 9 was for parallel rolling, and Test No. 10 was for roll cross rolling.Both the temperature, concentration, viscosity, emulsion particle size and supply amount of rolling oil, and the surface roughness of the work roll were all measured on the work roll axis. This is a case where the direction and the front and back sides of the plate are constant.

FIG. 7 shows the measurement of the difference in gloss between the front end A and the end C of the rolled material and the difference in gloss between the rear end A and the end C of the rolled material. The maximum value of the difference is shown for each test No. As a result, the test
In the case of Nos. 1 to 8, the difference in glossiness between the end portions A and C of the rolled material was small, and the same glossiness as in the case of Test No. 9 in which parallel rolling was performed was obtained. On the other hand, in the case of Test No. 10, which is the roll cross rolling of the comparative example, the difference in glossiness between the end portions A and C of the rolled material was large, and the commercial value of the appearance of the rolled sheet was extremely low.

The roll cloth cold rolling method of the present invention is as follows.
It changes the surface roughness of the work roll or the supply condition of the rolling oil in the axial direction of the work roll, and is limited by the material of the plate material to be rolled, the material of the work roll, the type of the rolling oil, the type of the rolling mill, and the like. Not something.

[0041]

[Table 1]

[0042]

[Table 2-1]

[0043]

[Table 2-2]

[0044]

According to the method of the present invention, even if the upper and lower work rolls are crossed in a horizontal plane and the sheet material is cold-rolled, uniform and good gloss is obtained in the width direction of the rolled sheet by a relatively simple method. A rolled sheet having excellent appearance quality can be manufactured. In addition, equipment can be dealt with only by modifying the existing rolling oil supply device and replacing work rolls, so that the equipment cost is small and no special installation space is required. Furthermore, even when applied to a cold tandem rolling mill, it is possible to prevent the rolling line from becoming complicated and long.

[Brief description of the drawings]

FIG. 1 is a plan view showing that upper and lower work rolls cross each horizontal plane at an intersection angle α.

2 (a), 2 (b) and 2 (c) are cross-sectional views of FIG.
The graph shows changes in the angle of engagement θ ₁ into the upper work roll and the angle of engagement θ ₂ into the lower work roll at the end A, the center B, and the end C of the plate material, respectively.

FIG. 3 is a diagram illustrating that the glossiness of a rolled plate changes in the width direction of the plate and that the upper surface and the lower surface of the rolled plate are different.

FIG. 4 (a) shows the correlation between the glossiness of a rolled sheet and the temperature of rolling oil.

FIG. 4 (b) shows the correlation between the glossiness of a rolled plate and the concentration of rolling oil.

FIG. 4 (c) shows a correlation between glossiness of a rolled plate and viscosity of a rolling oil.

FIG. 4 (d) shows the correlation between the glossiness of a rolling plate and the emulsion particle size of the rolling oil.

FIG. 4 (e) shows the correlation between the glossiness of a rolled plate and the supply amount of rolling oil.

FIG. 5 is a view for explaining that a supply nozzle of a rolling oil is divided into five parts in a plate width direction.

FIG. 6 is a diagram illustrating that the surface roughness of a work roll is changed in the axial direction of the work roll in correspondence with nozzle numbers of divided supply nozzles.

FIG. 7 illustrates the maximum value of the difference in gloss between the end A and the end C of the rolled material for each test No.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ken Masui 4-5-33 Kitahama, Chuo-ku, Osaka-shi, Osaka Sumitomo Metal Industries, Ltd. (72) Inventor Ryuji Hamada 4 Kitahama, Chuo-ku, Osaka-shi, Osaka No. 5-33 Sumitomo Metal Industries, Ltd. (72) Inventor Tetsuo Kajiwara 4-62 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd.Hiroshima Research Laboratory (72) Inventor Masaru Matsumoto Atsunoura, Nagasaki City, Nagasaki Prefecture No. 1-1, Machi Nagasaki Laboratory, Mitsubishi Heavy Industries, Ltd. (56) References JP-A-63-252601 (JP, A) JP-A-6-106202 (JP, A) JP-B-4-74081 (JP, B2) (58) Field surveyed (Int. Cl. ⁶ , DB name) B21B 1/00

Claims (1)

(57) [Claims] 1. A method for cold rolling a sheet material by intersecting upper and lower work rolls in a horizontal plane, wherein at least one of temperature, concentration, viscosity, emulsion particle size and supply amount of a rolling oil, and surface roughness of the work rolls. A roll cloth cold rolling method characterized in that one of them is changed in a work roll axis direction.