JP3823736B2 - Steel plate processing equipment and steel plate manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a steel sheet processing facility, particularly in a continuous line, when a fine particle is sprayed onto a steel plate to adjust surface roughness, surface hardness, etc., and relates to a processing facility that improves the cleanliness of the steel plate, The present invention relates to a method of manufacturing a steel sheet using such equipment.
[0002]
[Prior art]
In order to improve the press formability of a cold-rolled steel sheet or a galvanized steel sheet and the sharpness after painting, it is important to appropriately control the surface roughness of the steel sheet. For example, the average roughness Ra and peak count PPI of the steel sheet are important factors for improving oil retention between the dies in press forming and preventing die galling. Further, in order to improve the sharpness after painting, it is necessary to lower the waviness Wca representing the height of the long-period unevenness.
[0003]
In general, surface roughness is imparted to cold-rolled steel sheets and galvanized steel sheets by temper rolling, and the method of adjusting the roughness of the steel sheet by transferring the roughness of the surface of the rolling roll. It has been. For example, in the manufacture of a cold-rolled steel sheet, temper rolling is performed after a hot rolling process, a pickling process, a cold rolling process, and an annealing process, and the surface roughness is adjusted.
[0004]
In addition, although annealing and temper rolling are normally performed continuously by a continuous annealing line, it may be processed with a batch-type temper rolling mill after annealing. Moreover, in manufacture of a hot-dip galvanized steel sheet, temper rolling is performed after passing through a hot rolling process, a pickling process, a cold rolling process, an annealing process, and a plating process, and surface roughness is adjusted. Here, the annealing step, the plating step, and the temper rolling step are usually performed continuously in the hot dipping line, but the plated steel sheet may be processed by a batch-type temper rolling mill.
[0005]
However, in temper rolling, the original function is to adjust mechanical properties such as removing the yield point elongation of the steel sheet that occurs during annealing by imparting a plastic strain of about 0.5 to 2.0% to the steel sheet. In addition, it is also necessary to correct the shape of the steel sheet to be flat by giving bending deformation to the rolling roll, and a plurality of functions are required in a single process.
[0006]
Therefore, there are certain restrictions even when an appropriate surface roughness is imparted to the steel sheet, and it is difficult to freely control the surface roughness. For example, in temper rolling, when it is desired to increase the average roughness of the steel sheet, it is possible to increase the roll roughness transfer by increasing the rolling force, but increasing the rolling force As a result, the yield stress of the product increases and the elongation decreases, and the target mechanical characteristics may not be obtained.
[0007]
Moreover, since the pressure of the roll bite in the temper rolling is about several times the yield stress of the steel sheet, when the roll roll and the steel sheet slide under such high surface pressure, the roll roll wears. The surface roughness of the steel sheet changes with time. Therefore, the surface roughness is usually greatly different between the steel plate manufactured by the initial rolling roll and the steel plate manufactured at the stage where wear has progressed, and a steel plate having a certain surface roughness is continuously obtained. I can't.
[0008]
As a method for solving such a problem, a method for imparting surface roughness by directly injecting solid particles onto a steel plate together with a liquid without using temper rolling is disclosed in JP-A-59-6363. Yes. This is a method of injecting solid particles having a particle diameter of about 30 to 100 μm onto a hot-plated steel sheet and then injecting pressure water or compressed air to clean the surface of the plating film. It is disclosed in the above publication that the case where the liquid is ejected together with the liquid is included. And it is supposed that the crack resistance of a plating film can be improved by this.
[0009]
[Problems to be Solved by the Invention]
However, when fine particles having an average particle diameter of 300 μm or less are injected together with the liquid onto the steel plate, the following problems occur. In general, even if the solid particles become fine, the solid particles can be kept dispersed in the liquid if the weight of the particles contained in the liquid is not more than a certain value. However, when solid particles are jetted together with the liquid onto the steel sheet and collide with the surface of the steel sheet, the liquid itself easily flows down from the steel sheet, but the solid particles are difficult to flow on the steel sheet.
[0010]
In particular, once the liquid flows down from the steel plate and the content of the solid particles remaining on the steel plate increases, the apparent viscosity of the liquid / solid mixture suddenly increases and the liquid becomes difficult to flow. This is the same phenomenon as when mud splashes on the body of an automobile, even if the water flows down, mud adheres to the body and remains. In particular, in steel sheet production lines for steel, the temperature of the steel sheet is often higher than room temperature due to the annealing process or rolling process, so the liquid component may not only flow down from the steel sheet but also evaporate. Adhesion becomes stronger.
[0011]
Such a phenomenon does not have a great influence when the solid particles are always sprayed together with the liquid on the fixed steel plate, but appears remarkably when it is sprayed onto the continuously transported steel plate. That is, when the solid particles are always ejected together with the liquid, even if the solid particles once adhere to the steel plate, most of the solid particles are washed away by the subsequent ejection of the liquid. However, for a steel plate that is continuously transported, the portion where the solid particles are jetted moves immediately, so that the solid particles that have once adhered are transported in the state of being adhered to the steel plate as they are. is there.
[0012]
Thus, when the state which the content rate of the solid particle with respect to the liquid component raised on the steel plate arises, while solid particle aggregates on a steel plate, it will become difficult to remove from a steel plate. In particular, the smaller the particle size of the solid particles, the stronger the aggregation and the stronger the adhesion to the steel plate. In Japanese Patent Laid-Open No. 59-6363, even when dry blasting is performed or when solid particles are injected together with a liquid, pressure water or compressed air is injected after the solid particles are injected. Although disclosed, when solid particles are sprayed together with a liquid onto a continuously conveyed steel plate, it is not sufficient even if the fine particles adhering to the steel plate can be removed with compressed air.
[0013]
Furthermore, when a surface roughness measuring instrument or a surface defect meter is disposed downstream of the surface roughness imparting device, these measuring instruments are erroneously detected due to the influence of fine particles adhering to the steel sheet. Problems also arise.
[0014]
Moreover, even if it is a case where a solid water particle is firmly removed by injecting pressure water onto a steel plate, a trace amount of particles may remain on the steel plate. For example, a minute crack may occur in the plate end portion of the steel plate, and a minute amount of fine particles may be trapped in such a portion together with the liquid. In this case, since the surface tension of the liquid works, the fine particles cannot be easily removed. In particular, in cold-rolled steel sheets and hot-dip steel sheets for automotive applications, it is not desirable that solid particles remain on the steel sheet, and it is necessary to remove even a trace amount.
[0015]
Furthermore, a surface roughness imparting device that ejects solid particles together with a liquid needs to use a circulation device for circulating and reusing the liquid and solid particles. At this time, since the solid particles adhering to the steel plate are taken out of the circulation system from the surface roughness imparting device, there is a problem that the yield of the solid particles is deteriorated and the production cost is increased.
[0016]
Moreover, spraying solid particles on the surface of the steel sheet may be performed for the purpose of surface hardening, removal of impurity layers such as a surface oxide layer, surface activation, surface defect concealment, etc. in addition to surface roughness adjustment. . In such a case, the same problem as described above occurs.
[0017]
The present invention has been made in view of such circumstances, and is an apparatus that injects fine solid particles onto the surface of a continuously conveyed steel sheet, and prevents the solid particles from remaining on the surface of the steel sheet. It is an object to provide a facility capable of obtaining a clean steel plate, efficiently collecting solid particles, and improving the yield, and a method for producing a steel plate using such a facility. And
[0018]
[Means for Solving the Problems]
  The first means for solving the above problems is arranged on the downstream side of a solid particle injection device that injects solid particles having an average particle size of 300 μm or less together with a liquid onto the surface of a continuously conveyed steel plate. Have steel plate cleaning equipmentAnd a forced drying device for a steel plate is disposed downstream of the cleaning device, and an air wiping device is disposed downstream of the forced drying device.This is a steel plate processing facility.
[0019]
In this means, after injecting solid particles onto the steel plate surface, the steel plate is passed through a cleaning device. The cleaning device is not particularly limited as long as it has a function of washing off solid particles remaining on the surface of the steel plate, but a cleaning device using water is suitable. In this case, fine particles on the steel plate are used. It is necessary to inject a certain amount of pressure and flow rate in order to wash out the water. In particular, as the average particle size of the solid particles is smaller, the solid particles adhere more strongly on the steel plate, and thus higher pressure is required. However, 10kgf / cm²It is sufficient to use the following pressure water. It is also effective to increase the effect of washing away the fine particles by adding a surfactant to the washing water.
[0020]
The surface roughness imparting device is not particularly limited as long as it adjusts the surface roughness by injecting solid particles having an average particle size of 300 μm or less together with the liquid. And the mixture of solid particles are pumped and supplied to the nozzle, while the compressed air is injected from the nozzle to accelerate the mixture of liquid and solid particles and inject it onto the steel plate The method is a commonly used method.
[0021]
In this means, the property of the surface of the steel sheet can be made predetermined, and solid particles can be prevented from adhering to the steel sheet or floating on the steel sheet, so that a clean steel sheet is obtained. be able to. Furthermore, if the solid particles recovered by washing are recycled, the yield can be improved and the operating cost can be reduced.
[0023]
By disposing a device for forcibly drying the steel plate on the downstream side of the cleaning device, the cleanliness of the steel plate can be increased. That is, although most of the fine particles are removed from the steel plate cleaned by the cleaning device, a very small amount of fine particles may remain on the steel plate. In particular, there may be a minute crack at the end of the steel plate, and a small amount of fine particles may be trapped in such a portion together with the cleaning liquid. In this case, since the surface tension of the liquid works as described above, the fine particles cannot be easily removed, but the fine particles can be easily removed by drying the steel sheet and evaporating the remaining liquid of the cleaning liquid. it can.
[0025]
  In order to remove the fine particles after the steel plate is dried, it is sufficient to inject compressed air with an air wiping device. Originally, only a very small amount of fine particles remain, so there is no dust that can scatter around and cause trouble..
[0026]
The forced drying apparatus is an apparatus for evaporating the cleaning liquid on the surface of the steel sheet remaining after cleaning, and is not particularly limited, but a hot air dryer or an electric heating dryer can be used. Therefore, in this case, it is possible to simultaneously perform the drying of the steel plate and the air wiping in the forced drying apparatus.
[0027]
  The second means for solving the above-mentioned problem isIn the first means, an air nozzle of the air wiping device is arranged so that an air flow is directed from the center of the plate toward the end of the plate with respect to the periphery of the end of the plate of the steel plate. To do.
[0028]
  The first means is mainly intended to remove the solid particles remaining at the end of the steel plate, which could not be sufficiently removed by the cleaning device, so it is necessary to inject compressed air over the entire surface of the steel plate. Rather, the air nozzle may be arranged so that the air flow is directed from the center of the plate toward the end of the plate with respect to the periphery of the plate end of the steel plate.
[0030]
  To solve the above problemsThird meansIsIn the steel sheet processing facility as the first means or the second means, a temper rolling mill is provided on the upstream side of the solid particle injection device, and between the temper rolling mill and the solid particle injection device. The steel plate cleaning device is arranged.It is the processing equipment of the steel plate characterized by this.
[0031]
  When spraying onto a fine steel plate, even if foreign matter such as wear adheres to the surface of the steel plate, most of it is removed together with the liquid, and the uniformity of the surface roughness of the steel plate is not often impaired. However, when solid particles are circulated and used, foreign matter that has flowed down into the circulation system is mixed and adhered to the piping of the circulation system, and when sprayed from the nozzle onto the steel sheet, it creates indentations on the steel sheet surface. The latter problem is particularly serious. Therefore, it is preferable to clean the steel plate before jetting the fine particles by previously removing foreign matters remaining on the steel plate by washing.
[0032]
  The cleaning device is not particularly limited as long as it can perform the above functions, but a method of spraying water onto a steel plate is economical, and the spray pressure is usually 10kgf / cm 2 or less is sufficient. However, it may be necessary to spray a larger amount of pressure water in order to firmly remove the foreign matter adhering to the steel plate surface.
[0033]
When a temper rolling mill is installed in the hot dipping line, a temper rolling liquid may be used to prevent plating metal from being transferred to the rolling roll and causing scratches. In this case, the rust preventive agent, which is a component of the temper rolling liquid, remains on the steel sheet, and may be recognized as unevenness in appearance after imparting surface roughness, so it remains on such a steel sheet. It is effective to remove the components of the temper rolling liquid with a cleaning device.
[0036]
In the continuous annealing line, the steel sheet after cold rolling is annealed to adjust the material, and a temper rolling mill is often arranged on the downstream side thereof. In this temper rolling, there are a wet case using a temper rolling solution and a dry type case, but in any case, after removing foreign matter such as wear powder generated by temper rolling, the surface roughness By passing through the applying device, it becomes possible to obtain a steel plate that is clean and uniform in surface roughness, with no foreign matter mixed into the circulation system of the mixture of liquid and solid particles.
[0037]
  To solve the above problemsThe fourth means, Solid particles with an average particle size of 300 μm or less were sprayed along with the liquid onto the surface of the steel sheet being continuously conveyedThereafter, the steel plate is washed, then dried, and the solid particles remaining on the dried steel plate are removed by compressed air.It is a manufacturing method of the steel plate characterized by having.
[0038]
In this means, the property of the surface of the steel sheet can be made predetermined, and solid particles can be prevented from adhering to the steel sheet or floating on the steel sheet, so that a clean steel sheet is obtained. be able to. Furthermore, if the solid particles recovered by washing are recycled, the yield can be improved and the operating cost can be reduced.
[0039]
  To solve the above problemsThe fifth means,Before the step of the steel sheet manufacturing method as the fourth means, there is a cleaning step of removing the temper rolling liquid of the temper rolling mill and the wear powder generated by the temper rolling. Is the method.
[0040]
In this means, the surface properties of the steel sheet can be made predetermined, and foreign matters generated in the previous process can be mixed with the solid particles when the solid particles are circulated and damage the surface of the steel sheet. Can be prevented.
[0043]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an outline of a steel sheet surface roughness adjusting facility according to a first embodiment of the present invention. FIG. 1 shows an equipment row for adjusting the surface roughness by the surface roughness applying device 5 while continuously conveying the steel plate 1. As the steel plate 1, a cold-rolled steel plate or a galvanized steel plate is usually used. In the case of a cold-rolled steel plate, it is desirable to perform temper rolling after cold rolling and continuous annealing to adjust mechanical properties. Moreover, when providing surface roughness to a hot dip galvanized steel plate, what carried out cold rolling, annealing, galvanization, and performed temper rolling is suitable. However, this line may be passed before temper rolling to give surface roughness, and then temper rolling may be performed. Moreover, the steel plate 1 is not limited to a cold-rolled steel plate or a galvanized steel plate, and may be another surface-treated steel plate.
[0044]
FIG. 1 shows a facility in which such a steel plate 1 is loaded into a payoff reel 30 and wound up by a tension reel 31. At this time, the steel sheet is continuously conveyed in a state where tension is applied between the entry side bridle roll 11 and the exit side bridle roll 13.
[0045]
The surface roughness applying device 5 includes a blast chamber surrounded by a chamber and injectors 3a, 3b, 3c, and 3d. Inside the blast chamber, jetting machines 3a, 3b, 3c and 3d for jetting solid particles together with the liquid are arranged on the front and back surfaces of the steel sheet, and a mixture of liquid and solid particles is supplied from the circulation tank 6. Is done.
[0046]
As a type of the injector, the pneumatic injector shown in FIG. 4 can be used. This is to send the air compressed by the compressor 43 to the blast nozzle 42, accelerate the mixture of liquid and solid particles, and inject it onto the steel plate. At this time, the mixture of liquid and solid particles dropped to the lower part of the blast chamber is stored in the circulation tank 41, and after the solid particles are dispersed in the liquid by the stirrer 40, the mixture is supplied to the blast nozzle 42 for circulation.
[0047]
The injectors 3a, 3b, 3c, and 3d and the circulation tank 6 shown in FIG. 1 correspond to the blast nozzle 42, the circulation tank 41, and the agitator 40 in FIG. In addition, the pressure of the compressed air normally used is set to a pressure of about 0.2 to 0.8 MPa, and the surface roughness of the steel sheet can be adjusted by adjusting the pressure. Moreover, it is necessary to arrange a plurality of the injectors 3a, 3b, 3c, and 3d so that the injection density in the width direction of the steel plate is constant.
[0048]
FIG. 1 shows a form in which two rows of spray nozzles are arranged on each of the front surface and the back surface, but in the traveling direction of the steel plate, the spray density to the steel plate is in a certain range according to the line speed. In this way, one or a plurality are arranged. However, it is not always necessary to inject the solid particles to the steel plate on the front and back surfaces, and it may be injected only on one side according to the purpose.
[0049]
The embodiment of FIG. 1 is characterized in that a steel plate cleaning device 21 and a forced drying device 22 are arranged downstream of the surface roughness imparting device 5. Here, the cleaning device 21 uses a method of spraying water onto the steel plate. The pressure and flow rate of the washing water to be injected must be set higher as the particle size of the solid particles is smaller, but the pressure is 10 kgf / cm.²It is sufficient to use the following pressure water.
[0050]
A waste pit 26 is disposed at the lower part of the cleaning device, and solid particles are separated and collected by a fluid cyclone or the like in order to remove foreign substances and the like. The solid particles recovered in this way can be supplied to the circulation tank 6 and circulated again. However, a pipe may be directly connected from the waste pit 26 to the circulation tank 6 to automatically return the solid particles to the circulation system. In any case, it is possible to solve the problem that the yield is deteriorated by bringing solid particles out of the blast chamber.
[0051]
Moreover, the forced drying apparatus 22 is an apparatus which dries a steel plate using a warm air dryer, and evaporates the water | moisture content adhering to the steel plate with a washing | cleaning apparatus. However, a large-capacity apparatus is required to remove all the water on the steel plate that has been cleaned with a hot air dryer. Therefore, it is desirable that an air wiper capable of air wiping to inject compressed air onto the steel plate is disposed between the cleaning device 21 and the forced drying device 22. Thus, most of the moisture can be removed from the steel plate, and the remaining moisture may be evaporated by the forced drying device 22.
[0052]
Further, on the downstream side of the forced drying device 22, air wipers 24a and 24b capable of air wiping for injecting compressed air onto the steel plate are arranged. This may be a method in which compressed air is injected over the entire surface of the steel sheet, but an air nozzle is arranged around the edge of the steel plate so that the air flow is directed from the center of the plate to the edge of the plate. Is enough. In particular, it becomes possible to easily remove a minute amount of fine particles trapped together with the cleaning liquid in a minute crack portion seen at the end portion of the steel plate, thereby improving the cleanliness of the steel plate.
[0053]
By the way, in the present invention, in order to adjust the surface form of the hot dip galvanized steel sheet, a surface form measuring instrument is arranged on the downstream side of the bridle roll 13, and the injection speed and the injection amount of the solid particles are determined based on the measurement result. It may be changed. The surface form measuring device may be an average roughness Ra or peak count PPI measuring device, and a device that photographs the surface of a steel plate with a CCD camera or the like and determines the size of the indentation of solid particles by image processing. . At this time, there is no problem that the detectors erroneously detect due to the influence of the solid particles attached to the surface of the steel plate.
[0054]
On the other hand, a steel plate cleaning device 27 is disposed upstream of the surface roughness imparting device 5. As a result, the foreign matter adhering to the steel sheet on the entry side is removed and does not enter the circulation system of the surface roughness imparting device 5, so that it is sprayed from the nozzle onto the steel sheet and causes an indentation of the foreign matter on the steel sheet surface. The problem does not occur. As a cleaning device, it is economical to inject water onto a steel plate, and the injection pressure is usually 10 kgf / cm.²The following is sufficient. When oil and fat components are attached to the steel plate 1, cleaning water containing a cleaning agent may be used. Further, when a large amount of oil and fat components such as rolling oil adheres to the steel plate 1, an alkaline degreasing facility may be arranged.
[0055]
FIG. 2 is a diagram showing an outline of the steel sheet surface roughness adjusting equipment according to the second embodiment of the present invention. This shows an embodiment according to claim 8, in which the equipment row according to claim 6 is arranged downstream of the plating bath 34 of the hot dip galvanizing line.
[0056]
In the hot dip galvanizing line, the cold-rolled steel sheet is loaded into the payoff reel 30 and passed through the inlet side cleaning device 32, and then recrystallization annealing is performed in the annealing furnace 33. Thereafter, after forming a galvanized film in the plating bath 34, the film thickness is adjusted by the air wiper 35. When manufacturing an alloyed hot-dip galvanized steel sheet, the alloying furnace 36 is further operated to perform an alloying process. However, a galvanized steel sheet in which the film produced without using this mainly comprises a η layer is also produced on the same line.
[0057]
In a normal hot dip galvanizing line, after temper rolling is performed by the temper rolling mill 20, a case where a chemical conversion film is applied by a chemical conversion treatment device or a case where rust preventive oil is applied and wound up as it is. is there. On the other hand, in the embodiment of FIG. 2, nozzles 25a and 25b for injecting water or temper rolling liquid are arranged on the entrance side of the temper rolling, and further, a surface roughness imparting device 5 and a steel plate cleaning device are arranged on the downstream side. 21. A forced drying device 22 is arranged.
[0058]
Here, so-called wet pressure adjustment is performed in which temper rolling is performed while supplying water to the steel plate and the roll. Since the water sprayed on the steel plate 1 has an action of washing out foreign matters such as wear powder generated by temper rolling, the inlet side cleaning device 27 of FIG. 1 is not necessarily required in this case.
[0059]
When the steel plate 1 that has passed through the surface roughness imparting device 5 passes through the cleaning device 21, the mixture of liquid and solid particles adhering to the surface of the steel plate 1 is washed away. This mixture is collected in the waste liquid pit 26, and solid particles are separated by a fluid cyclone or the like. The solid particles recovered in this manner are returned again to the circulation tank 6 and used for circulation, so that the yield of solid particles does not deteriorate.
[0060]
By arranging in the equipment row as described above, the plating equipment, the temper rolling equipment for adjusting the mechanical properties of the material, and the surface roughness imparting device 5 for imparting an appropriate surface roughness are arranged in the same line. Compared with the batch type surface roughness adjusting equipment shown in FIG. 1, the productivity can be greatly improved.
[0061]
FIG. 3 is a diagram showing an outline of the steel sheet surface roughness adjusting equipment according to the third embodiment of the present invention. This shows an embodiment according to claim 9, in which a temper rolling mill 20 is arranged downstream of the annealing furnace 33 of the continuous annealing line, and a steel plate entrance cleaning device is further provided downstream thereof. 27, the equipment row | line | column which has arrange | positioned continuously the surface roughness provision apparatus 5, the exit side washing | cleaning apparatus 21, the forced drying apparatus 22, and the air wipers 24a and 24b.
[0062]
In the continuous annealing line, the cold-rolled steel sheet 1 is charged into the payoff reel 30 and recrystallization annealing is performed in the annealing furnace 33. In a normal continuous annealing line, after temper rolling is performed by the temper rolling machine 20, anti-rust oil is applied and wound on the tension reel 31. On the other hand, in the embodiment of FIG. 3, the surface roughness imparting device 5 and the like are arranged on the downstream side of the temper rolling mill 20.
[0063]
A temper rolling mill arranged in a normal continuous annealing line performs dry pressure adjustment performed in a dry process and wet wet pressure adjustment. FIG. 3 shows a case where dry pressure adjustment is performed. In this case, since foreign matter such as wear powder generated by temper rolling remains on the steel plate, it is desirable to remove the foreign matter adhering to the steel plate in advance by the entry side cleaning device 27.
[0064]
By arranging in the equipment row as described above, the continuous annealing equipment, the temper rolling mill for adjusting the mechanical properties of the material, and the surface roughness imparting device 5 for imparting an appropriate surface roughness are arranged in the same line. Compared with the batch type surface roughness adjusting equipment shown in FIG. 1, the productivity can be greatly improved.
[0065]
【Example】
As an example of the present invention, a hot-dip galvanized steel sheet having a thickness of 0.5 to 1.8 mm and a sheet width of 750 to 1850 mm as a base, a steel sheet provided with 0.8% elongation by a temper rolling mill. The result of using and adjusting the surface roughness with the equipment as shown in FIG. 1 will be described. In addition, the provision of the elongation rate in temper rolling is for the purpose of material adjustment, and temper rolling is performed using a bright roll. In this example, the galvanized steel sheet whose plating film mainly consists of η phase was used. The maximum line speed was 100 mpm.
[0066]
The solid particles used in the surface roughness imparting device 5 are fine particles of stainless steel having an average particle diameter of 55 μm. As the injector, the pneumatic injector shown in FIG. 4 was used, and the compressed air pressure was 0.4 MPa and the distance between the steel plate and the injector was 200 mm. The spray density of the solid particles was 2.5 kg / m with respect to the steel sheet, and thereby an automotive galvanized steel sheet having an average roughness Ra of 1.1 μm and a peak count PPI of 420 was produced.
[0067]
In the cleaning device 21, cleaning was performed by spraying water onto the steel plate at a flow rate of 20 L / min from the spray nozzle. The forced drying apparatus 22 was operated using a hot air dryer at a hot air temperature of 100 ° C. and a hot air injection speed of 100 m / s. Air wiping nozzles 24 a and 24 b are arranged on the downstream side of the forced drying device 22.
[0068]
As a result, most of the solid particles remaining on the steel sheet from the surface roughness applying device 5 and taken out of the blast chamber are washed away by the cleaning device, and compared with the case where the cleaning device 21 is not disposed, the basic unit, In other words, the supply amount of solid particles was reduced by 55%.
[0069]
In the above embodiments and examples, the apparatus and method for adjusting the surface roughness of the steel sheet have been described. However, the present invention is not limited to this, and the surface of the steel sheet is hardened. The present invention can also be applied to the case where solid particles are projected on the surface of a steel sheet in order to remove an impurity layer such as a surface oxide layer, activate the surface, conceal specular defects, and the like.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a steel sheet surface roughness adjusting facility according to a first embodiment of the present invention.
FIG. 2 is a diagram showing an outline of a steel sheet surface roughness adjusting facility according to a second embodiment of the present invention.
FIG. 3 is a diagram showing an outline of a steel sheet surface roughness adjusting facility according to a third embodiment of the present invention.
FIG. 4 is a schematic diagram showing a configuration of a pneumatic injector.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Steel plate, 3a, 3b, 3c, 3d ... Solid particle injector, 4a, 4b, 4c, 4d ... Compressor, 5 ... Surface imparting device, 6 ... Circulation tank, 10, 11, 13 ... Bridle roll, 20 ... Temper rolling mill, 21 ... Exit side cleaning device, 22 ... Forced drying device, 23 ... Inspection table, 24a, 24b ... Air wiping nozzle, 25a, 25b ... Water or temper rolling fluid injection nozzle, 26 ... Waste liquid tank, 27 ... Entry side cleaning device, 30 ... Pay-off reel, 31 ... Tension reel, 32 ... Entry side cleaning device, 33 ... Annealing furnace, 34 ... Plating bath, 35 ... Air wiper, 36 ... Alloying furnace, 40 ... Agitator, 41 ... circulation tank, 42 ... blast nozzle, 43 ... compressor

Claims (5)

A solid particle injection device that injects solid particles having an average particle size of 300 μm or less together with a liquid on the surface of the steel plate that is continuously conveyed, and a steel plate cleaning device disposed downstream thereof ; and A steel plate processing facility , wherein a steel plate forced drying device is disposed downstream of the cleaning device, and an air wiping device is disposed downstream of the forced drying device . The air nozzle of the said air wiping apparatus is arrange | positioned so that an air flow may go to a board edge part from the board center part with respect to the periphery of the board edge part of a steel plate, The steel plate of Claim 1 characterized by the above-mentioned. Processing equipment. A temper rolling mill is provided on the upstream side of the solid particle injection device in the steel sheet treatment facility according to claim 1 or 2, and the steel plate is disposed between the temper rolling mill and the solid particle injection device. A steel plate processing facility in which a cleaning device is arranged . After spraying solid particles with an average particle size of 300 μm or less together with liquid onto the surface of the steel plate that is continuously conveyed , the steel plate is washed and then dried, and the solid particles remaining on the dried steel plate are removed with compressed air The manufacturing method of the steel plate characterized by having the process to do. Before the process of the manufacturing method of the steel plate of Claim 4, it has the washing process which removes the temper rolling liquid of a temper rolling mill, and the abrasion powder produced by temper rolling, The manufacturing method of the steel plate characterized by the above-mentioned. .

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