JP2004058089A - Equipment and method for rolling cold-rolled steel strip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide equipment and a method for rolling a cold-rolled steel strip which is excellent in mill cleanness, with which the seizure of a coil at batch annealing is effectively prevented and which is excellent in reduction of the cost of equipment and productivity. <P>SOLUTION: In a rolling method with cold-rolling equipment of the steel strip with which one-way rolling is performed and in which fine projecting and recessing parts are transferred on the surface of a rolled stock after the final rolling with pressurizing rolls which are arranged on the downstream side of the rolling mills and which is provided with at least two rolling mills and take-up machines arranged on the outlet side of the rolling mills, a roll pressurizing device for pressurizing the rolled stock with at least two upper and lower rolls are provided between the take-up machines and the rolling mill nearest by the take-up machines and the rolled stock is wound with the take-up machines while transferring the ruggedness on the surfaces of the upper and lower pressurizing rolls on which the fine ruggedness is imparted to the surface of at least one side of the pressurizing rolls on the approximately whole surface of the rolled stock after the final rolling. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cold steel strip rolling facility and a rolling method.
[0002]
[Prior art]
Mill clean rolling and batch annealing techniques can be cited as techniques for reducing equipment costs and improving productivity. For example, JP-A-2000-87259 and JP-A-10-277613 are mentioned.
[0003]
[Problems to be solved by the invention]
Mill clean rolling using a mill clean rolling oil that maintains good surface cleanliness of the strip has a problem that the mill clean rolling oil has poor lubricity.
[0004]
In the batch annealing technique, dull rolling makes it difficult to perform high-pressure rolling and makes it difficult to reduce equipment.
[0005]
An object of the present invention is to provide a cold steel strip rolling equipment and a rolling method which are excellent in equipment cost reduction and productivity.
[0006]
[Means for Solving the Problems]
By a pressing roll arranged on the downstream side of the rolling mill, minute irregularities are transferred to the surface of the rolled material after the final rolling.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
(Example)
Cold rolling equipment is increasingly required to reduce equipment costs and improve productivity. To reduce equipment costs, the electrolytic cleaning (ECL) process for cleaning rolling oil and metal abrasion powder adhering to the strip surface should be omitted by mill clean rolling, or batch annealing equipment should be used instead of continuous annealing equipment. Etc. are performed. Next, the mill clean rolling and batch annealing techniques will be described.
[0008]
In the case of performing the mill clean rolling, especially in the case of thin plate rolling of 0.5 to 0.8 mm or less, a mill clean rolling oil that maintains good surface cleanliness of the strip is used. However, mill clean rolling oil has poor lubricity, and if it is used in all rolling, it becomes difficult to roll a thin plate, or the number of required rolling passes increases in a reversible rolling facility. Therefore, the mill clean rolling oil is used at the final stage in a tandem rolling plant and at the time of final rolling in a reversible rolling plant that is repeatedly rolled. In this case, it is desirable to avoid mixing the normal rolling oil with good lubricity and the mill clean rolling oil. This is because, if mixing occurs, it becomes difficult to control the rolling oil concentration and the like of the two, which causes deterioration of rolling quality. However, especially in a reversible rolling facility, it is substantially difficult to avoid the mixing, and almost no mill-clean material is produced in the same rolling facility.
[0009]
Further, when the strip wound in a coil shape is directly introduced into a heating furnace and then annealed, so-called batch annealing is performed, so that there is a high risk that baking occurs between the strip layers to deteriorate the product quality or to lower the yield. Become. This is likely to occur in the case of a thin plate of 0.5 mm or less. In order to avoid this, at least at the time of final rolling, dull rolling is performed using a dull roll having a surface with irregularities (dulles). That is, the unevenness of the dull roll surface is transferred to the strip surface to reduce the degree of adhesion between the coil layers, thereby preventing image sticking. In such dull rolling, as compared with so-called bright rolling using a smooth roll, the friction coefficient of the roll bite is higher and the rolling load is larger. For this reason, high pressure cannot be reduced by dull rolling. In tandem rolling equipment, dull rolling is performed at the final rolling stand. In this case, there is a problem that a large rolling reduction cannot be obtained in the final stand, a rolling reduction in the preceding stage becomes large, and severe rolling is required. In addition, when rolling of a thin plate, a hard material or the like is included, there is a case where the number of rolling stands must be increased due to the necessity of dull rolling.
[0010]
In addition, when dull rolling is performed in the reversible rolling facility, the number of required repetitive rolling increases, which causes a reduction in production. When mill clean oil is used for such dull rolling, it is difficult to further reduce the rolling. Further, when the same rolling stand is used for both bright and dull rolling, it is necessary to frequently change the roll from a bright roll to a dull roll, and a reduction in productivity is inevitable. On the other hand, it is conceivable to speed up the roll change. However, the change to the dull roll and the bright roll requires at least two times in rolling each coil. Therefore, frequent change of rolls still occurs, and the essential problem has not been solved.
[0011]
Further, in the dull rolling, minute wear powder (dull powder) of the plate and the roll is generated, easily mixed into the rolling oil, and harmful to the mill clean rolling. For this purpose, a so-called magnetic separator that adsorbs and removes the dull powder using a magnet or the like is often installed.
[0012]
However, the rolling oil is usually also used for cooling the rolls, and the flow rate is several thousand l / min per stand, so that the magnetic separator has to be increased in size and equipment cost increases. At this time, since the oil attached to the dull powder is also removed, there is a disadvantage that the consumption of the rolling oil increases.
[0013]
As described above, in particular, when performing mill clean and dull rolling by thin plate rolling of 0.5 to 0.8 mm or less, there are various problems such as a decrease in productivity and an increase in equipment costs.
[0014]
Embodiments of the present invention use a simple and inexpensive dulling device, primarily for dulling and rolling prior to batch annealing, to improve quality for mill clean material rolling and subsequent batch annealing processes. Further, the use of a dulling device enables high pressure.
[0015]
In the embodiment of the present invention, attention has been paid to the fact that the problem in the prior art is caused by performing dull rolling or mill clean rolling by a high-pressure rolling mill. In other words, a new cold rolling equipment that uses an inexpensive dulling device dedicated to dulling separately from the rolling mill, has good mill cleanability, and can effectively prevent coiling during batch annealing. The main purpose is to provide a rolling method.
[0016]
FIG. 2 shows an example of a roll transfer apparatus used in the present invention, which provides fine irregularities on the roll surface and presses and transfers this to a plate. As shown in the figure, the roll transfer device has a structure in which an upper and lower roll 2 that directly contacts and presses a rolled material 1 is supported by a frame 4 via bearing boxes 3 installed at the ends of each roll. A hydraulic jack 5 is provided at the lower part of the frame 4, whereby the rolling box 1 is pressed with an appropriate load by moving the bearing box of the lower roll up and down. The pressing load is measured by a load cell 6 installed between the upper roll 2 and the frame 4. The upper and lower rolls 2 are driven via a motor (not shown), a pinion stand, and a spindle 7 installed on one of the upper and lower rolls 2. Here, at least one of the upper and lower rolls 2 is a transfer roll having fine irregularities on the roll surface. When the rolled material 1 is pressed by such a vertical roll with a hydraulic jack, the surface pattern of the roll can be transferred to the rolled material surface.
[0017]
FIG. 1 shows an embodiment in which the present invention is applied to a so-called two-stand reversible rolling facility in which two rolling mills 8 and 9 are installed and rolling is repeated. In this embodiment, the roll transfer device
10 was set between the rolling mill 9 and the tension reel 13. Rolling coil first
The roll 12 is inserted into a payoff reel 11 and then unwound and transported to two rolling mills 9 and 8 via pinch rolls 14 and 15 and a roll transfer device 10. Subsequently, the rolled material 1 rolled by the rolling mills 9 and 8 is wound on a tension reel 17 via a pinch roll 16 to perform a first pass rolling. The rolling of the first pass is stopped when the tail end of the normal coil reaches the vicinity of the pinch roll 15 of the tension reel 13, and the rolling of the second pass is started in the opposite direction. In the second pass rolling, the rolled material 1 is tensioned from the tail end of the coil via the pinch roll 15 to a tension reel.
It is continued while winding at 13. Hereinafter, when the rolling is further repeated as necessary, the rolled material 1 is wound up between the left and right tension reels 13 and 17 and unrolled, whereby the rolling is performed.
[0018]
In order to cool the rolling roll 18 and the rolled material 1 and to lubricate the rolling roll bite, so-called coolant oil is supplied to the rolling mills 8 and 9 at necessary locations. In the present embodiment, the rolling oil 20 in the roll coolant tank 19 is supplied to the rolling mills 8 and 9 through a pipe 22, valves 23 and 24 and a nozzle header 25 using a coolant pump 21. The rolling oil 20 is normally supplied to the entrance side in the rolling direction. For example, in the first pass (odd pass) of the present embodiment, the rolling oil 20 is supplied to the rolling mills 8 and 9 from the inlet nozzle header 25 by closing the valve 23 and opening the valve 24. In the second pass (even pass), the valve
By closing the valve 24 and opening the valve 23, the rolling oil 20 is supplied from the nozzle header 25 on the opposite side. The rolling oil 20 supplied to the rolling mills 8 and 9 is collected in an oil pan 26 provided below the rolling mills, collected in a roll coolant tank 19 through a pipe 27, and returned to the rolling mills 8 and 9 again. Supplied. When the rolled material 1 is a general carbon steel, a so-called emulsion oil in which an oil component (base oil) is emulsified in water is often used as the rolled oil 20 as described above. Further, mineral oil, synthetic ester oil and the like are often used as the base oil.
[0019]
Further, a cleaning oil is supplied to the roll transfer device 10 for the purpose of lubricating the pressing portion and cleaning the pressing roll 2 and the rolled material 1. The cleaning oil 29 in the tank 28 is pumped
30, the ink is supplied to the roll transfer device 10 via a pipe 31 and a nozzle header 32. The supplied cleaning oil 29 is collected in an oil pan 33 provided at a lower part of the roll transfer device 10, and returned to the tank 28 via a pipe 34. The cleaning oil 29 may be a general mill clean rolling oil, detergent rolling oil, hot water or the like. When the same oil as the roll coolant oil is used, the concentration of the oil is set lower than the concentration of the roll coolant oil.
[0020]
Most of the rolled material rolled in this facility is shipped through a subsequent annealing step. Annealing is broadly classified into so-called continuous annealing in which the coil is unwound and run in an annealing furnace to perform continuous annealing, and batch annealing in which the wound coil is put into an annealing furnace for annealing. Normally, in the case of continuous annealing, a step of cleaning the sheet surface by electrolytic cleaning (ECL) or the like is usually performed before annealing, and the cleanliness of the sheet surface immediately after rolling is not a problem.
[0021]
However, in the case of batch annealing, since it is handled as a wound coil, it is almost impossible to clean the plate surface. Therefore, if the surface of the plate after rolling has a large amount of residue such as base oil and the surface is poorly cleaned, the residue of annealing of the base oil and the like will remain on the plate surface during annealing, and the product quality will be significantly impaired.
[0022]
In the case of batch annealing, during the annealing, seizure is likely to occur between the strip layers of the coil, particularly in the case of a thin plate of 0.5 mm or less.
[0023]
In the two-stand reversible cold rolling equipment as described above, most products are produced by two-pass rolling (four times in total) in the case of general carbon steel except for hard rolled materials such as stainless steel. Here, it is assumed that the required number of rolling passes is an even number. As shown in FIG. 1, a roll transfer device 10 for transferring a dull to a rolled material 1 was installed between a tension reel 13 on which a payoff reel 11 was installed and a rolling mill 9. In a pass other than the final pass, the roll transfer device 10 increases the interval between the upper and lower rolls 2 so that the rolled material 1 is passed without being pressed, or is simply pressed lightly. On the other hand, in the final pass (even-numbered pass), the rolled material 1 is pressed with an appropriate load, and a necessary dull line is transferred to the rolled plate. In this way, dull rolling by the rolling mills 8 and 9 becomes unnecessary, and the rolling reduction of the rolling mills 8 and 9 can be made large. Therefore, even when dulling is necessary, it is not necessary to increase the number of rolling passes for dull rolling. In addition, the roll change required when performing the bright and dull rolling in the rolling mill 8 or 9 is, of course, unnecessary, and high productivity can be maintained.
[0024]
Furthermore, in order to prevent burning during annealing, the tension reel in the last pass
It is desirable to reduce the winding tension of No. 13. This is because the larger the winding tension, the larger the coil tightening force, the higher the adhesion between the strip layers, and the easier the baking. In order to prevent this, when winding is performed while reducing the output side tension of the rolling mill 9 in the final pass, the rolling load of the rolling mill 9 increases, and it is difficult to apply a large reduction. On the other hand, even if the entry side tension of the rolling mill 9 is increased, the rolling load of the rolling mill 9 is reduced. However, if only the entry side tension is excessively increased, the problem that the rolling becomes unstable occurs. This is because a neutral point where the peripheral speed of the roll is equal to the speed of the plate is present outside the roll bite. In the case of at least the final pass for performing the dulling, the tension between the rolling mill 9 and the roll transfer device 10 can be set high by controlling the drive torque of the roll transfer device 10 or the like. The winding tension between the roll transfer device 10 and the tension reel 13 can be weakly controlled independently of the exit tension of the rolling mill 9. Normally, the winding tension can be easily controlled by controlling the torque of the tension reel 13. Therefore, the rolling load of the rolling mill 9 can be kept small, and the winding tension of the tension reel 13 can be reduced. Thereby, it can be said that the rolling reduction of the rolling mill can be greatly increased, and it is also suitable for preventing the annealing coil from burning.
[0025]
Further, this embodiment is also suitable for mill clean rolling. That is, the cleaning oil 29 can be supplied to the entry side of the roll transfer device 10 independently of the rolling oil 20 supplied to the rolling mills 8 and 9. Accordingly, the rolling oils 8 and 9 can use the rolling oil 20 which is poor in mill cleanliness but excellent in lubricity, so that the rolling reduction in the rolling mills 8 and 9 can be increased. Further, since the cleaning oil 29 can be appropriately selected and used irrespective of the rolling oil 20, a rolled material having good mill cleanability can be produced.
[0026]
When dull rolling is performed on the final pass by the rolling mill 9, the rolling oil enters the unevenness of the surface of the rolled material, and the residual oil amount on the surface of the rolled material increases. FIG. 3 shows an example of the test results. The horizontal axis in FIG. 3 represents the rolling load, and the vertical axis represents the residual oil amount on the surface of the rolled material. In the test, after rolling using a dull roll, the residual oil amount after wiping the rolling oil on the rolled material surface with a roll wiper was examined. Generally, the larger the dull rolling load, the better the unevenness of the roll surface is transferred to the rolled material. On the other hand, in FIG. 3, it can be seen that the larger the dull rolling load, the larger the residual oil amount and the worse the mill cleanability. However, according to the present embodiment, there is no need to perform dull rolling in the rolling mills 8 and 9, and the rolled material 1 is cleaned on the entry side of the roll transfer device 10 that gives a dull, so that the above problem does not occur. From the above, it can be said that this embodiment is very suitable for mill clean rolling.
[0027]
Further, the embodiment of FIG. 1 shows a reversible cold rolling facility in which two rolling mills are separately installed. The distance between the rolling mills 8 and 9 needs to be approximately 3 to 5 m. If this distance is made as short as possible, the rolling equipment will be more compact, and it will be effective in improving the rolled material yield.
[0028]
FIG. 4 shows an embodiment using a single stand. In this embodiment, the roll transfer device 10 is installed between the payoff reel 11 and the tension reel 13. In many cases, the number of passes required in reversible rolling on a single stand is about four, which is about double that of two stands. When the number of times of repeated rolling is large, it is preferable to arrange the tension reels 13 and 17 as close to the rolling mill 35 as possible. Thereby, the monitoring of the rolling state is also facilitated, and the operation is facilitated. However, in the final pass, the rolled material 1 is not wound on the tension reel 13 but is wound on the payoff reel 11 via the roll transfer device 10. At this time, the winding tension of the pay-off reel 11 can be set lower by the effect of the roll transfer device 10 as in the case of the two stand. Therefore, there is no need to design the mechanical strength of the pay-off reel 11 as high as that of the tension reel. It may be on par with a normal payoff reel, or may have a little margin. Thus, the production cost of the pay-off reel 11 is not much different from the conventional one. The payoff reel 11 is installed so as to be reversible so as to perform winding and unwinding. The arrangement in which the roll transfer device 10 is installed between the payoff reel 11 and the tension reel 13 can be applied to a two-stand reversible rolling facility.
[0029]
In the above description, the roll transfer device 10 is always arranged on the payoff reel side. This is suitable when the number of required repeated rolling passes is an even number. If the number of required repetitive rolling passes is an odd number, the final pass must be performed via the roll transfer device 10, so an extra pass is added once, and the productivity is reduced. Therefore, as shown in FIG. 5, for example, a payoff reel 36 may be further added to the outside of the tension reel 17. If the required number of passes is an even pass, the coil 12 is first inserted into the payoff reel 11, and rolling is started. When the required number of passes is an odd-numbered pass, the coil 12 is first inserted into the payoff reel 36, and rolling is started. The final pass at this time is in the same direction as that of the even pass. Accordingly, necessary irregularities can be provided on the surface of the rolled material 1 by the roll transfer device 10 without increasing the number of extra passes. In FIG. 4, the roll transfer device 10 can be installed at two places between the rolling mill 35 and the left and right tension reels 13 and 17 instead of between the payoff reel 11 and the tension reel 13. Even if it does in this way, the required unevenness | corrugation is given to the rolled material surface, without increasing an extra pass | pass, whether the number of passes is an even number or an odd number. However, for rolled materials that do not require dull rolling, the roll transfer device 10 need not be used in the final pass.
[0030]
Further, in a pass other than the final pass, it is also possible to perform rolling while pressing a rolled material by a roll transfer device for all passes, for example. In particular, if the present roll transfer device is used, the tension between the roll transfer device and the rolling mill can be increased independently of the tension reel. In the case of the two-stand mill shown in FIG. 1, the tension between the rolling mills 8 and 9 can be set stronger without making the rolling of the rolling mill 9 unstable in each pass. Thus, the rolling mill 9 can reduce the pressure more strongly in each pass. Furthermore, the winding tension of the tension reel 13 can be kept low. This means that a design in which the strength of the tension reel 13 is weakened becomes possible, and the manufacturing cost of the tension reel 13 can be reduced. The above effects are achieved even when the roll of the roll transfer device 10 is a smooth bright roll. Therefore, even in the case of rolling other than the dull rolled material, if a bright roll is used as the pressing roll, the present roll transfer device can be effectively used.
[0031]
Next, a case where the present invention is applied to a cold tandem rolling facility will be described. FIG. 6 shows an example of tandem rolling equipment in which the rolled material 1 conveyed from the entry side is continuously rolled by four rolling mills 38 to 41 and wound up by a tension reel 42 via a pinch roll 14. The roll transfer device 10 is installed between the final rolling mill 41 and the tension reel 42. Each rolling mill
For 38 to 41, rolling oil excellent in lubricity can be used, and it is possible to increase the rolling reduction. Further, since the rolled material 1 can be washed on the entry side of the roll transfer device 10, it is possible to produce a product having excellent mill cleanability. The dull transfer using such a roll transfer device is performed at least immediately after final rolling and before winding. At this time, in order to give a predetermined amount of transfer to the rolled material, it is necessary to apply a minimum necessary pressing force to the rolled material. The required pressing force varies depending on the material of the rolled material, the total rolling reduction of the rolling, and the like, but can be easily obtained by experiment or experience. The rolling load required for ordinary rolling (approximately 0.8 t / mm in linear pressure) may be considerably smaller, and in most cases, the linear load may be approximately 0.3 t / mm or less. However, when the reduction amount is larger than the pressing force, the plate shape is disturbed by the roll transfer device. In order to prevent this as much as possible, the upper and lower rolls of the transfer device may be provided with a roll crown that gradually tapers from the roll center to the roll end. For the roll crown, a parabolic shape symmetrical about the center of the roll is usually sufficient. The roll crown amount may be determined based on the actually required pressing force or the like. In order to properly cope with wide variations in the sheet width or material, it is desirable to prepare a plurality of stay rolls having different crowns. Further, it is preferable that the roll transfer device is provided with a shape control means for controlling the plate shape. It is desirable that the control means has a simple structure as much as possible.
[0032]
FIG. 7 shows an example of the control means. In FIG. 7, an outer cylinder 44 is shrink-fitted to the roll shaft 43, and the inside of the roll shaft 43 and the outer cylinder 44 is formed into an oil chamber 45. High-pressure oil is sealed at a predetermined pressure from a hydraulic pressure generating device 48 through the pipe 46 and the rotary joint 47 installed at the shaft end. The outer cylinder 44 is deformed according to the sealing pressure. The deformation amount (roll crown amount) of the outer cylinder 44 can be controlled by changing the sealing pressure. By using a roll having such a shape and controlling the sealing pressure, the plate shape can be easily controlled. When the above-mentioned VC roll is applied to the present embodiment, there is another advantage besides providing the shape control means. The VC roll has a larger Hertz flatness at the load acting portion in contact with the rolled material than the solid roll. This corresponds to the fact that the contact length between the rolled material and the roll becomes longer, and the rolled material is pressed with a larger diameter roll. When the rolled material is pressed with the same pressing force, the larger the roll, the smaller the amount of reduction. When the plate is pressed with a pressing force necessary for transferring the surface irregularities of the roll, the VC roll has a smaller rolling reduction and a less disordered plate shape than a solid roll. Although this property is not preferable because a large amount of reduction cannot be obtained in ordinary rolling, it can be said that this property is effective for the roll pressing device in this embodiment.
[0033]
Another example of the shape control means is a four-stage cross mill. By crossing the upper and lower rolls in opposite directions, the gap between the rolls in the plate width direction is made variable and the plate shape is controlled. If this cross mechanism is applied to a roll transfer device, the plate shape can be easily controlled. Further, the plate shape can be controlled by shifting the upper and lower rolls in opposite directions. For example, the plate shape can be controlled by giving roll crowns having a substantially cubic curve shape to the upper and lower roll surfaces and shifting them in opposite directions. Even with a shift amount of about 100 mm, a large control ability can be provided, so that it can be realized with a simple shift structure. The above shape control means is suitable for controlling the body crown at the center of the plate.
[0034]
Next, a description will be given of the control of a sharp decrease in the thickness and edge drop near the edge of the plate. When the plate is pressed by the roll transfer device, some edge drop occurs depending on the pressing load and the like. For this reason, a shift is performed by giving a local tapered crown (hereinafter referred to as a single crown) to one of the roll ends. In this case, since the one crown portion is pressed against the plate edge, a large shift amount is required when the plate width range of the rolled material is wide. When such a mechanism is incorporated in the roll transfer device, the shift structure becomes complicated. Therefore, at least one rolling mill applied to the cold rolling equipment is a single crown shift mill for shifting a roll having a single crown. Thereby, the edge drop generated in the roll transfer device can be predicted or feedback-controlled by the one-crown shift mill. Also, from the viewpoint that the shape is not disturbed as much as possible, it is preferable that the pressing roll of the roll transfer device has a large diameter. However, the larger the diameter of the pressing roll, the larger the amount of edge drop. In this sense, it can be said that providing the rolling mill with the edge drop control means has the effect of making the present invention more and more effective.
[0035]
Although the two-stage roll transfer device has been described above, a four-stage roll transfer device having a reinforcing roll 49 in contact with the upper and lower pressing rolls 2 may be used. In this case, the diameter of the pressing roll can be made smaller than that of the two-stage roll transfer device. That is, the disorder of the shape increases. The above relationship will be described with reference to the graph of FIG. FIG. 8 shows a calculation example of the rolling reduction when the horizontal axis is the pressure roll diameter and the vertical axis is pressed by the pressure roll. However, the plate thickness is 0.7 mm and the deformation resistance is 70 kg / mm ² And the average surface pressure inside the contact tool between the pressing roll and the plate is constant
(113kg / mm ² ). Here, the average surface pressure was used as a parameter instead of the pressing force. This is because the transfer of the roll pattern to the plate strongly depends on the average surface pressure. However, the average surface pressure is substantially proportional to the pressing force, and in actual control or the like, the pressing force can be more easily measured and convenient. For this reason, the description so far has been based on the pressing force. In the calculation example of FIG. 8, when the roll diameter is set to 400 mm or less, the rolling reduction is 10% or more. If the roll diameter is 600 mm or more, the rolling reduction is as very small as about 2.5% or less. When the rolling reduction is 5% or less, the roll diameter may be approximately 550 mm or more. Preferably, it is more than 600 mm. In this case, the rolling reduction is about 3% or less, and the influence on the plate shape is extremely reduced.
[0036]
When a large-diameter pressing roll is used, the roll transfer device becomes large in the four-stage roll transfer device, and the production cost increases. However, when the pressing roll has a small diameter of, for example, 400 mm or less, the influence on the plate shape increases, and it is not so good. In contrast, when a small-diameter pressing roll is used, it is conceivable to increase the flatness of the contact roll of the pressing roll. As a result, the contact length between the roll and the plate increases, and the effect of using a substantially large-diameter pressing roll can be obtained. When a hollow roll is used, the contact flat spring constant between the rolls can be approximately calculated. When the inner diameter of the roll is about half the outer diameter, the spring constant is about 3.2 t / mm per unit width. ² It becomes. This is approximately the same value as the contact flat spring constant of the solid roll. Further, when the inner diameter is set to 60% of the outer diameter, the contact flat spring constant is about 1.4 t / mm. ² And about half of the above. Therefore, by making the inner diameter of the hollow roll approximately half or more of the outer diameter, the contact length between the rolled material and the pressing roll can be increased, and the effect of using the large-diameter roll can be obtained.
[0037]
If the pressing roll 2 of the four-stage roll transfer device shown in FIG. 9 is a hollow roll, it is a small-diameter pressing roll and has little effect on the plate shape. As shown in FIG. 10, the structure is such that one hollow pressing roll 50 is supported by two reinforcing rolls 51, and the pressing force of the hollow pressing roll 50 is dispersed and supported to increase the fatigue strength of the hollow pressing roll 50. be able to. Oil pressure may be applied to the inner diameter side of the hollow roll. However, when the diameter of the pressing roll is reduced and the necessary driving torque cannot be transmitted, the reinforcing roll is driven.
[0038]
The dull roll generally refers to a roll provided with random fine irregularities of about several microns on the roll surface. In this embodiment, fine irregularities may be regularly provided on the roll surface and transferred to the plate surface.
[0039]
It is desirable to install measuring instruments such as a shape detector, a tension meter and a plate speedometer. The shape detector can be installed before or after the roll transfer device. When the roll transfer device 10 is installed between the tension reel 13 and the rolling mill 9 as shown in FIG. 1, it is preferable that the shape detector is installed between the roll transfer device 10 and the tension reel 13. It is desirable to employ a rolling mill having a high level of shape control capability, such as a UC mill, so that the shape disturbance after the roll transfer device can be corrected on the rolling mill side by prediction or feedback control. The shape control means of the roll transfer device can be extremely simplified, and the cost of the roll transfer device can be reduced.
[0040]
Performing the dulling at the entry side of the rolling mill and subsequently rolling has another effect. A higher pressure can be achieved by rolling with a bright roll while rolling oil is applied to the roll bite portion before rolling (hereinafter referred to as high pressure rolling). This is because when the rolling oil enters the unevenness on the surface of the rolled material, the lubricity in the rolling roll bite portion is improved. When the rolling roll of the rolling mill is a dull roll, a large rolling reduction cannot be obtained because the elongation of the rolled material is restricted by the unevenness of the dull roll. An embodiment of a reversible rolling facility under higher pressure utilizing the above effects will be described with reference to FIG. FIG. 11 shows an example of a one-stand reversible rolling facility, in which a roll transfer device 10 is installed between a tension reel 13 and a rolling mill 35. On both sides of the roll transfer device 10, nozzle headers 32a and 32b for supplying the cleaning oil 29 are provided, and can be switched by valves 52 and 53. In the present embodiment, high-pressure rolling can be performed by rolling in odd-numbered passes. For example, when performing high-pressure rolling in one pass, the rolled material 1 unwound from the payoff reel 11 is transported to the rolling mill 35 while being pressed by the roll transfer device 10. At this time, the valve 52 is closed and the valve 53 is opened, and the cleaning oil 29 is supplied from the nozzle header 32b to the entry side of the roll transfer device 10. In the rolling mill 35, the rolled material 1 is rolled and rolled up by the tension reel 17 while supplying rolling oil from the inlet nozzle header 25. Since the roll transfer device is not installed on the entry side of the rolling mill 35 in the subsequent second pass rolling, high-pressure rolling using the roll transfer device cannot be performed, and the rolling is directly performed while being wound by the tension reel 13. At this time, the roll transfer device 10 does not press the rolled material 1 or presses it very lightly. When lightly pressed, the cleaning oil 29 is supplied from the nozzle header 32a. The third pass is the same as the first pass except that the rolled material 1 is unwound from the tension reel 13. Therefore, minute irregularities can be transferred to the surface of the rolled material 1 immediately before rolling, and the lubricity in the roll bite portion can be improved and the pressure can be further reduced. However, although the amount of residual oil of the cleaning liquid remaining on the surface of the rolled material may increase, the tank volume of the rolling oil is usually 10,000 liters or more, and the cleaning liquid brought into the rolling oil is very small and is particularly problematic in practical use. Absent. In addition, it is possible to cope with this by making the cleaning liquid the same type as the rolling oil and reducing its concentration. Further, a roll transfer device may be provided between the tension reel 17 and the rolling mill 35. With this configuration, high-pressure rolling can be performed in all passes. Mill clean rolling is possible regardless of whether the final pass is an odd or even pass.
[0041]
The above rolling method is effective even if the roll transfer device 10 is installed between the tension reel 13 and the payoff reel 11 in FIG. The nozzle headers 32 are installed on both sides of the roll transfer device 10, and the high-pressure rolling is performed only in the first pass. It is also possible to apply to the tandem rolling equipment shown in FIG. At this time, a roll transfer device is provided on the entry side of the rolling mill 38. Since the rolling is performed in only one direction, the nozzle header of the cleaning liquid may be provided only on the entry side in this case.
[0042]
As described above, the present embodiment is not only suitable for mill clean rolling and preventing burning during annealing, but also has the effect of enabling higher pressure rolling.
[0043]
【The invention's effect】
Advantageous Effects of Invention According to the present invention, it is possible to provide a cold steel strip rolling facility and a rolling method excellent in equipment cost reduction and productivity.
[Brief description of the drawings]
FIG. 1 shows an embodiment of the present invention.
FIG. 2 is a structural diagram of a roll transfer device.
FIG. 3 is an explanatory diagram of a residual oil amount.
FIG. 4 shows an embodiment of the present invention.
FIG. 5 shows an embodiment of the present invention.
FIG. 6 shows an embodiment of the present invention.
FIG. 7 is an explanatory diagram of a shape control device.
FIG. 8 is an explanatory diagram of a pressing roll and a draft.
FIG. 9 is a structural modification of a roll transfer device.
FIG. 10 is a structural modification of a roll transfer device.
FIG. 11 shows an example of high-pressure rolling according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Rolled material, 8, 9, 35, 38-41 ... Rolling machine, 10 ... Roll transfer device,
11, 36 ... payoff reel, 13, 17, 42 ... tension reel, 14,
15, 16: Pinch roll, 19: Coolant tank, 20: Rolling oil, 21: Coolant pump, 25, 32: Nozzle header, 26, 33: Oil pan, 28: Tank, 29: Cleaning oil, 30: Pump.

Claims (12)

A cold strip rolling equipment for unidirectional rolling, comprising at least two rolling mills and a winder arranged on the output side of the rolling mill, wherein the rolling mill closest to the winder and the winder is provided. A cold pressing machine provided with a roll pressing device for pressing a rolled material by at least two upper and lower rolls, and providing fine irregularities on at least one surface of the pressing roll over substantially the entire surface. Strip rolling equipment. At least one rolling mill, and a winding machine on the inlet and outlet sides of the rolling mill, a cold strip rolling equipment for reversible rolling, wherein the rolling mill and the rolling mill closest to the winding machine A cold steel, characterized in that a roll pressing device for pressing a rolled material by at least two upper and lower rolls is provided on at least one of the rolls, and minute unevenness is provided on substantially the entire surface of at least one surface of the pressing roll. Strip rolling equipment. A cold strip mill for reversible rolling, comprising at least one rolling mill and a winder on the entrance and exit sides of the rolling mill,
An unwinder is provided on at least one of the winders,
Between the unwinding machine and the winding machine, a roll pressing device for pressing a rolled material by at least two upper and lower rolls is provided,
A cold steel strip rolling facility, wherein fine irregularities are provided on at least one surface of at least one of the pressing rolls. In the cold steel strip rolling equipment according to claim 1,
A cold strip rolling equipment comprising: a driving device for driving a pressing roll of the roll pressing device; a detecting unit for detecting a pressing force; and a control unit for controlling the pressing force. In the cold steel strip rolling equipment according to claim 1,
A cold steel strip rolling facility, characterized in that the pressing roll of the roll pressing device is provided with a convex crown that tapers toward the roll end substantially symmetrically with respect to the center of the pressing roll. In the cold steel strip rolling equipment according to claim 1,
A cold steel strip rolling facility, characterized in that the roll pressing device is provided with width direction pressing control means for pressing the rolled material sheet in the width direction substantially uniformly. In the cold steel strip rolling equipment according to claim 1,
A cold steel strip provided with fluid supply means for supplying a fluid to the roll pressing device, wherein the fluid supplied by the fluid supply means is a fluid different from the rolling oil supplied to the rolling mill. Rolling equipment. In the cold steel strip rolling equipment according to claim 1,
A cold strip rolling equipment comprising a batch annealing device for annealing a rolled coil. A rolling method for a cold strip rolling equipment comprising at least two rolling mills and a winder arranged on the exit side of the rolling mill, and performing unidirectional rolling, wherein at least one surface has fine irregularities. A rolling method, characterized in that the unevenness of the surface of the upper and lower pressing rolls applied to substantially the entire surface is wound by the winding machine while being transferred to the surface of the rolled material after the final rolling. In the rolling method according to claim 10,
A rolling method characterized in that pressing is performed while supplying a fluid different from rolling oil to the upper and lower pressing rolls. In the rolling method according to claim 10,
A rolling method, wherein the winding tension between the roll pressing device and the winding machine is made smaller than the tension on the rolling mill between the roll pressing device provided with the pressing roll and the rolling mill, and rolling is performed. At least one rolling mill, and a rolling method for a rolling facility equipped with a roll pressing device that presses a rolled material using a pressing roll having at least one of the rolling mills provided with microscopic irregularities on substantially the entire surface thereof, While supplying a fluid different from rolling oil to the roll pressing device to the entry side of the roll pressing device with respect to the rolling material traveling direction, the unevenness of the pressing roll surface is transferred to the rolled material surface, and the A rolling method characterized by rolling while supplying rolling oil.

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