JP2003305647A - Surface treatment facility of metal plate, surface treatment method and manufacturing method of metal plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface treatment facility and surface treatment method of a steel plate capable of carrying out uniform treatment even in the case of using a plurality of gas type blast nozzles and favorable in efficiency. <P>SOLUTION: Compressed gas generated in a compressor 21 is delivered to each of the gas type blast nozzles 23a-23d through a pressure regulator 22. Supply of solid particulates to the gas type blast nozzles 23a-23d is carried out from a storage tank 24, and solid particulates supply quantity regulators 25a-25d are set to regulate supply quantity of the solid particulates to each of the gas type blast nozzles 23a-23d. Consequently, it is possible to individually regulate the solid particulate supply quantity of each of the gas type blast nozzles 23a-23d and to regulate the respective supply quantity in accordance with distribution of surface roughness of the steel plate. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a surface of a metal plate such as a galvanized steel plate with fine solid particles to provide a surface roughness of fine microscopic roughness on the surface of the metal plate. The present invention relates to equipment for performing a surface treatment such as the above, a method therefor, and a method for producing a metal plate having the surface treatment method in its production process.

[0002]

2. Description of the Related Art For thin steel sheets used for press forming such as galvanized steel sheets and cold rolled steel sheets, it is necessary to appropriately adjust the surface roughness of the steel sheets. The reason for this is that by imparting a certain surface roughness, the oil retaining property with the mold during press molding is enhanced, and troubles such as mold galling and steel plate breakage are prevented. For example, if the sliding resistance between the steel plate and the mold increases, the steel plate is likely to break on the punch surface or the steel plate near the bead portion.

In order to adjust the surface roughness of the steel sheet, usually, the surface of the rolling roll is provided with a certain microscopic unevenness,
A means of transferring the unevenness is used in the temper rolling process. However, in the temper rolling, the method of transferring the surface roughness of the roll cannot provide fine unevenness, and the surface roughness of the steel sheet changes due to the change of the roll roughness over time due to roll wear or the like. There was a problem such as being lost.

The present inventors have found a method for adjusting the surface roughness of galvanized steel sheet or the like by projecting fine solid particles directly onto the steel sheet surface as a means different from the conventional temper rolling method. . This is because the spherical solid particles collide with the surface of the steel sheet to form a large number of microscopic depressions.
A so-called dimple-shaped microscopic unevenness is formed. Such a surface morphology is particularly excellent in the effect of improving the oil retaining property with the mold in press molding, and can significantly improve the press moldability. Also, the smaller the particle size of the projected solid particles, the finer the unevenness is imparted to the surface of the steel sheet at a short pitch, so the sharpness after painting is also improved, and a steel sheet suitable for automotive outer panel applications, etc. It is possible to obtain.

A gas type projection device is known as a means for projecting solid particles. The gas-type projection device uses a gas-type blast nozzle to accelerate a compressed gas in the nozzle and utilizes the drag to accelerate solid particles. In particular, it is suitable for projecting fine particles having a small mass of solid particles, and is characterized in that the speed of solid particles can be made extremely high.

For example, the technique disclosed in Japanese Patent Laid-Open No. 3-294418 discloses an average particle diameter for cold-rolled steel sheet in order to obtain good press formability and clearness after painting.
The shot particles of 30 to 100 μm are projected onto the steel plate,
This is a method of controlling the center line waviness of the steel sheet within a certain range and adjusting the area ratio of the crater portion within a certain range. As a concrete means, a method of processing by the gas type projection device is disclosed.

[0007]

However, JP-A-3-2
Japanese Patent No. 94418 does not disclose how to arrange a gas blast nozzle on a steel plate to obtain uniform surface roughness. In particular, in order to process a wide steel plate at a high speed like a steel manufacturing line, it is necessary to project a large amount of solid particles, and a single gas blast nozzle imparts surface roughness to the entire surface of the steel plate. It is impossible to do.

For example, a normal gas type blast nozzle has a nozzle inner diameter of about 5 to 20 mm, and the range in which it can be sprayed on the surface of a steel sheet is limited to a region of about 30 to 50 mm in diameter. Further, the projection amount from the injection nozzle varies depending on the particle size of the solid particles, the specific gravity, the pressure of the compressed gas, etc., but is usually 10 kg / min or less.

At this time, in order to process one side of a steel plate having a plate width of 1000 mm which is passed at a line speed of 100 mpm, when the amount of solid particles projected per unit area of the steel plate is 2.5 kg / m ² , It is necessary to project the solid particles at 250 kg / min. Therefore, 5kg / m as a gas blast nozzle
Even if you use something that can project in, at least
It is necessary to arrange 50 gas blast nozzles.

In arranging such a large number of gas blast nozzles, the surface roughness of the steel plate must be made uniform. In particular, the press formability of the steel sheet is the average roughness of the steel sheet surface imparted by the projection of solid particles,
Since the peak count and the area ratio of the dimple-like unevenness formed by the projection of solid particles have an effect, the press formability of the product depends on the part of the steel plate unless uniform microscopic unevenness is given to the steel plate surface. The problem of variation occurs. However, the above publication does not disclose any specific means for making the surface roughness of the steel sheet uniform when a plurality of gas blast nozzles are used.

Further, in the case of using the gas type blast nozzle, the energy efficiency is lower than that of the centrifugal rotor type solid particle projection apparatus utilizing the centrifugal force, and when a large number of gas type blast nozzles are used, a compressor having a large capacity is used. I need. Therefore, in order to reduce the cost for imparting surface roughness to the steel sheet, it is necessary to set and operate more efficient solid particle projection conditions.

The present invention has been made in view of the above circumstances. Even when a plurality of gas blast nozzles are used, uniform treatment can be performed, and an efficient steel plate surface treatment facility and It is an object of the present invention to provide a surface treatment method, and further a method for manufacturing a steel sheet using the surface treatment method for a steel sheet.

[0013]

[Means for Solving the Problems] A first means for solving the above-mentioned problems is a plate width of a metal plate which is continuously conveyed by a gas blast nozzle for injecting solid particles having an average particle diameter of 300 μm or less. Surface treatment equipment for a metal plate, characterized by comprising a projection condition adjusting device for arranging a plurality of nozzles in a direction and adjusting the injection condition of the solid particles from each nozzle individually or for each preset combination. 1).

The metal plates targeted by this means are mainly cold-rolled steel plates and surface-treated steel plates. Cold rolled steel sheets include special steel such as high carbon steel, electromagnetic steel sheets, and amber, in addition to ordinary steel. The surface-treated steel sheet includes various surface-treated steel sheets that have been surface-treated by means such as hot dipping or electroplating, and the galvanized steel sheet is the main target. This is because press formability and image clarity after coating are often required, and a dense and uniform surface roughness (a form of microscopic irregularities on the surface) of the steel sheet is required. Therefore, descaling treatment of hot rolled steel sheet for the purpose of blasting action by projection of solid particles is not included. As described above, the present means and other means mainly target steel sheets such as cold rolled steel sheets and surface-treated steel sheets, but other metals such as aluminum and aluminum alloy sheets, titanium and titanium alloy sheets, etc. It can also be applied to plates, and covers all metal plates.

On the surface of such a metal plate, an average particle size of 300
The reason why the solid particles having a size of μm or less are projected is to provide minute pitch irregularities on the surface of the metal plate densely. That is, by projecting the solid particles onto the surface of the metal plate, the kinetic energy of the solid particles is converted into indentation work on the surface of the metal plate, and an indentation (recess) is generated on the surface of the metal plate. The size of the indentation at this time becomes smaller as the particle diameter of the solid particles becomes smaller, and minute recesses are formed. That is, by projecting a large number of solid particles, a large number of minute indentations are formed on the surface of the metal plate, and microscopic unevenness that is more dense and has a very short interval between the indentations is formed. By providing a so-called dimple-like form in which a large number of recesses are formed per unit area on the surface, it is possible to improve the oil retaining property between the mold and the metal plate when used for press working or the like. It is possible to improve the press moldability to a great extent.

When the average particle diameter of the solid particles exceeds 300 μm, microscopic asperities with a short pitch cannot be formed, and the effect of improving press formability cannot be expected, and at the same time the metal plate surface The long period irregularities, that is, the undulations are large, so that the cleanliness of the appearance is lost and the image clarity after coating is deteriorated. From such a point of view, in the case of densely providing short pitch irregularities on the steel plate surface of the cold rolled steel plate or the surface treated steel plate, it is necessary to set the average particle size of the solid particles to 300 μm or less, and 150 μm or less. Is more preferable.

As the solid particle projection means, the above-mentioned gas projection device is used. This is because it is a means suitable for projecting fine solid particles at high speed. This is a device for injecting a gas flow supplied from a compressed gas source and solid particles supplied from a solid particle supply device as a mixed fluid from a gas blast nozzle.

By the way, within the projection range of the solid particles by the single gas blast nozzle, more solid particles collide with each other in the central portion of the projection range, and the collision of the solid particles decreases toward the peripheral portion. This is because the flow velocity of the gas ejected from the gas blast nozzle has a distribution in the nozzle cross section, and solid particles collide with the inner wall of the nozzle, and the speed of the solid particles is likely to decrease. Therefore, by simply arranging the single gas blast nozzles, there are a portion where many solid particles collide with the surface of the metal plate and a portion where there are few solid particles, and it is not possible to ensure the uniformity of short pitch irregularities. Further, even if the gas blast nozzle is arranged so that the region where the solid particles collide with each other wraps in a certain range, it is difficult to predict the surface roughness in the lap portion.

Furthermore, since the solid particles that have collided with the metal plate are scattered around, if a plurality of gas blast nozzles are arranged close to each other, the solid particles projected by one of the gas blast nozzles are reflected on the metal plate. After that, it may be scattered by another gas blast nozzle to the area to be projected, and it may hinder the provision of irregularities with a short pitch in that area.

In order to solve such a problem, according to the present means, a plurality of gas blast nozzles are arranged in the plate width direction of the continuously conveyed metal plate, and individually or for each preset combination, An injection condition adjusting device for adjusting the injection condition of the solid particles from each nozzle is provided.

"Individually adjusting the injection conditions of the solid particles from each nozzle" means that the injection conditions such as the pressure of the compressed gas and the supply amount of the solid particles are independently applied to each nozzle of the gas blast nozzle. It means that it can be changed. There may be a separate compressor associated with each gas blast nozzle. Further, "for each preset combination" means that two or more gas blast nozzles are used as a set and the injection conditions can be changed only if they are the same, but the injection conditions can be changed independently for each set. Say.

If an injection condition adjusting device is provided for each gas blast nozzle so that the injection conditions of all the gas blast nozzles can be adjusted individually, the equipment cost therefor may increase and it may not be economical. In such a case, the injection condition may be adjusted “for each preset combination”. For example, if the width of the metal plate changes, the injection conditions of the gas blast nozzle that will be located near the edge of the plate width can be adjusted individually,
In the gas blast nozzle that is located in the center of the plate width and is not located near the edge of the plate width even if the plate width of the metal plate changes,
In some cases, even if a plurality of gas blast nozzles are combined and they are ejected only under the same conditions, it is possible to obtain sufficiently uniform short pitch irregularities.

The injection condition adjusting device is an adjusting device for changing a factor that can change the injection condition of the gas blast nozzle. The injection conditions that should be changed are:
There are conditions such as the pressure of the compressed gas, the supply amount of the solid particles, the distance between the nozzle and the metal plate or the interval between the adjacent gas blast nozzles, and any device that can change at least one of these conditions may be used.

By using the surface treating apparatus for a metal plate having a plurality of gas blast nozzles as described above, it is possible to easily make an adjustment for equalizing the minute short pitch irregularities provided on the surface of the metal plate. Therefore, even when a wide metal plate is processed at a high speed, a metal plate having uniform short pitch irregularities can be obtained early. Specifically, when uniforming the short pitch irregularities in the part where each projection range by the adjacent gas blast nozzle wraps, the spacing between those gas blast nozzles can be changed, or the surface at the wrap part can be changed. By adjusting the pressure of the compressed gas so that the roughness does not become excessive, it is possible to make the unevenness of a short pitch uniform.

Further, the solid particles projected by the gas type blast nozzle are reflected on the metal plate and then scattered to the area to be projected by another gas type blast nozzle, which hinders the provision of short pitch irregularities in that area. Even if it does, even if the solid particles jump into the projection range, the effect is reduced by increasing the injection pressure of the gas type blast nozzle that projects the solid particles to that area or increasing the supply amount of the solid particles. As a result, unevenness of short pitch unevenness is not locally generated on the surface of the metal plate.

A second means for solving the above-mentioned problems is as follows.
A gas blast nozzle that injects solid particles with an average particle diameter of 300 μm or less, in a surface treatment facility for a plurality of metal plates arranged in the plate width direction of a continuously conveyed metal plate, depending on the plate width of the metal plate. A surface treatment method for a metal plate having a function of changing a gas blast nozzle for injecting solid particles (claim 2).

When a plurality of gas type blast nozzles for projecting solid particles are arranged on the surface of the metal plate, it is necessary to arrange the gas type blast nozzles in accordance with the maximum plate width in the production line. However, the plate width of the metal plate to be processed is usually different for each coil, and when processing a metal plate with a plate width narrower than the maximum plate width, it was placed outside the plate width end. Even if the solid particles are jetted from the gas type blast nozzle, they do not contribute to the provision of the short pitch unevenness. Rather, when the solid particles are sprayed on the portion where the metal plate does not exist, the high-speed solid particles collide with the inside of the room covering the whole so that the solid particles do not scatter to the surroundings, and the peripheral devices are worn or damaged, which is preferable. Absent. Further, energy is required to supply the compressed gas to be jetted in those nozzles, which increases the manufacturing cost of the metal plate.

Therefore, in the present means, the injection of solid particles from the gas blast nozzles arranged outside the plate width of the metal plate to be treated is stopped individually or in combination set in advance. At this time, the supply of the solid particles to the gas type blast nozzle arranged outside the plate width of the metal plate to be treated may be stopped, or the supply of the compressed gas itself may be stopped. Further, since the metal plate does not always pass through the line center and meandering may occur, it is desirable to determine the gas blast nozzle to be stopped with a certain margin. Alternatively, the position of the end of the metal plate may be detected, and the gas blast nozzle to be stopped may be determined according to the output.

A third means for solving the above-mentioned problems is as follows.
After projecting solid particles, using a gas plate blast nozzle that injects solid particles with an average particle size of 300 μm or less, a plurality of metal plate surface treatment equipments arranged in the plate width direction of the continuously conveyed metal plate. Is characterized by measuring the surface roughness distribution of the metal plate and adjusting the injection conditions of the gas blast nozzle for injecting solid particles individually or for each preset combination based on the measured value. It is a method for surface treatment of a plate (claim 3).

The projection ranges of the adjacent gas blast nozzles need to be overlapped in a certain range so that the surface roughness of the metal plate becomes uniform. However, it is difficult to predict short pitch irregularities at the boundary. Also,
Even if the solid particles projected by the gas blast nozzle are reflected on the metal plate and interfere with each other in the area of the projection range by another gas blast nozzle, it is difficult to predict the short pitch irregularities in that area. . Therefore, the surface morphology in the plate width direction is measured after the solid particles are projected, and the injection pressure of the gas blast nozzle is increased or the supply amount of the solid particles is changed according to the measurement result. The surface morphology in the plate width direction can be made uniform with high accuracy.

A fourth means for solving the above-mentioned problems is as follows.
In the third means, the surface morphology has an average roughness R
a, maximum roughness Rmax, ten-point average roughness Rz, root-mean-square roughness Rq, peak count PPI, average mountain interval Sm, center waviness Wca, coverage of dimples formed by solid particles, one or more It is represented by a parameter (claim 4).

It is common to use the surface roughness of the metal plate and the average roughness Ra of the surface of the metal plate as an index showing the degree of short pitch irregularities of the metal plate, but the peak count PP
Various parameters such as I and center line waviness Wca may be used, and one or more of these parameters may be combined and used as an index of the surface roughness. This is because those parameters also influence the press formability of the metal plate and the image clarity after painting, and their uniformity affects the quality of the product. As a simple method of measuring the surface morphology, the glossiness specified in JIS Z 8741 and the color tone are measured by the Lab method specified in JIS Z 8730. It may be used as an index.

Further, the average roughness Ra is a parameter representing the average height of the short-period concavities and convexities obtained from the roughness curve, but if it is a parameter representing the height of the short-period concavities and convexities, the maximum roughness The height Rmax, the ten-point average roughness Rz, the root mean square roughness Rq, and the like may be used. The peak count PPI is the peak number of irregularities per inch, as defined by the SAE911 standard, and is an index indicating the length of the pitch of the unevenness of the metal plate surface, but a parameter that represents the pitch of the unevenness. Alternatively, the average mountain interval Sm may be used.

The center line waviness Wca is a parameter representative of the average height when only long-period irregularities on the surface of a metal plate specified in JIS B 0610 are extracted, and the post-painting image clarity is shown. Influences.

On the other hand, the average roughness Ra and the peak count PPI can be measured based on the light reflection intensity distribution. For example, regarding the light reflection characteristics analysis of cold rolled steel sheet and its online surface roughness measurement, iron and steel (70, 1984
Year, p.1095). Furthermore, for the centerline waviness Wca, frequency analysis of the light intensity distribution is performed to extract long-period frequency components,
There is a method of estimation based on the correspondence with the value of the center line waviness Wca.

In the present means, a large number of these measuring devices may be arranged in the plate width direction of the metal plate, or the distribution may be measured while scanning in the plate width direction of the metal plate. However, even if the surface roughness is not directly measured, the unevenness of the surface roughness is detected by measuring the distribution of the glossiness of the metal plate surface or the distribution of the reflected light.
The injection condition of the gas blast nozzle may be adjusted according to the output.

The fifth means for solving the above-mentioned problems is as follows.
In the fourth means, the injection conditions of the gas blast nozzle for injecting the solid particles include the pressure of the compressed gas, the supply amount of the solid particles, the distance between the adjacent gas blast nozzles, the nozzle and the metal plate. Of the distances, one or more conditions are satisfied (Claim 5).

The pressure of the compressed gas affects the velocity of the solid particles, and the higher the pressure of the compressed gas, the faster the solid particles are projected. Therefore, by increasing the pressure of the gas blast nozzle corresponding to the portion of the metal plate having a small short pitch unevenness, the short pitch unevenness of the metal plate is made uniform.

The supply amount of solid particles refers to the amount of solid particles supplied into the gas blast nozzle, and by increasing the supply amount, a fine microscopic asperity is imparted to the surface of the metal plate. Further, changing the interval between the adjacent gas blast nozzles is performed by changing the size of the lap portion when a region to be surface-roughened by a plurality of gas blast nozzles wraps. This is because the shapes can be made uniform.

FIG. 4 schematically shows this state. FIG. 4 shows a case where surface roughness is imparted to the surface of the steel sheet 1 by using two gas blast nozzles 41 and 42. FIG. 4A is a diagram viewed from the traveling direction of the steel sheet, and FIG. ) Is the figure which looked at the steel plate from the upper part. At this time, with only a single gas blast nozzle, the distribution of the surface roughness according to the velocity distribution of the solid particles occurs in the surface roughness imparting region, and the roughness of the peripheral portion is lower than that of the central portion. is doing. Therefore, if another gas blast nozzle is arranged so that the projection range overlaps, the solid particles will be projected twice in the peripheral area of the projection range and where the surface roughness is low. The surface roughness of the portion increases, and the surface roughness becomes uniform as a whole.

Further, the larger the distance between the gas blast nozzle and the metal plate, the longer the distance until the solid particles ejected from the nozzle reach the surface of the metal plate, and the air resistance during that time decreases the speed of the solid particles. It's easy to do. Therefore, the surface roughness of the metal plate can be made uniform by increasing the distance from the metal plate of the gas blast nozzle corresponding to the portion where the surface roughness of the metal plate is large.

In each of the above means, it is convenient to use air as the compressed gas. However, an inert gas such as nitrogen may be used when the solid particles are projected onto the surface of the active metal plate or when the solid particles used are an active metal or the like.

By the way, in any equipment and method from the first means to the present means, it is desirable that the solid particles to be projected are spherical shot particles. As the solid particles, a shot blast having a spherical particle shape or a grid blast having an angular shape is known, but the former is used to obtain a shot peening effect for hardening the surface of the work material, and the latter is It is usually used for grinding surfaces. Therefore, in imparting the surface roughness targeted by the present invention, it is desirable to use spherical shot particles in order to clean the surface to prevent damage as much as possible.

As the solid particles, it is preferable to use a metal material or a ceramic material having a density of 2 g / cm ³ or more. When the density of the solid particles is less than 2 g / cm ³ , the mass of the solid particles becomes small as described above, and unless the projection speed is made very high, the metal plate surface has irregularities of sufficient size. Because it becomes difficult. Therefore, plastic-based solid particles are not suitable. Further, since the solid particles projected on the metal plate scatter after forming indentations on the surface, it is preferable to provide a system for circulating and collecting the solid particles and projecting them. In the case of cyclic use, it is preferable that the solid particles have such strength that they will not be crushed even if they collide with the surface of the metal plate. Therefore, a material such as glass beads that is easily crushed is not excluded from the present invention, but is not preferable.

From this point of view, in any of the facilities and methods from the first means to the present means, the density is 2
It is preferable to use solid particles of a metal-based material or a ceramic-based material of g / cm ³ or more, specifically, steel balls,
Examples include steel grids, high speed steel, alumina, silicon oxide, diamond, zirconia oxide, and tungsten carbide.

By the way, in many cases, the above means
As the gas blast nozzle, a nozzle shape close to a circle or an ellipse is used, but a shape close to a flat nozzle may be used. Even in this case, if a single nozzle cannot cover the entire plate width, a plurality of nozzles must be arranged. In this case, the above means can be applied as it is.

A sixth means for solving the above-mentioned problems is as follows.
A method for manufacturing a metal plate (claim 6), characterized in that the method includes a surface treatment method for a metal plate, which is any one of the second means to the fourth means, in a manufacturing process thereof.

The metal plate surface treatment equipment of the present invention as described above is arranged in a metal plate manufacturing line, and the second to fourth means are for a metal plate excellent in surface characteristics. Applied in manufacturing. For example, a hot-dip galvanized steel sheet or a cold-rolled steel sheet having excellent surface characteristics is provided at least one of upstream and downstream of the temper rolling mill in the subsequent stage of the hot-dip galvanized steel sheet production line or the subsequent step of the continuous annealing line. Used to. According to this means, it is possible to manufacture a steel sheet while efficiently processing the steel sheet.

As described above, it is preferable to use the surface treatment equipment of the present invention in combination with the temper rolling mill. However, only the temper rolling mill is arranged in the hot-dip galvanized steel sheet production line or the continuous annealing line, and the present invention is used. The surface treatment equipment for the metal plate may be provided in a separate line to perform the surface treatment by batch treatment.

The hot-dip galvanized steel sheet shown here is hot-dip galvanized steel sheet, alloyed hot-dip galvanized steel sheet, hot-dip Al.
-Zn alloy plated steel sheet, hot-dip Zn-Al alloy plated steel sheet, etc. Further, the surface characteristics refer to surface characteristics that affect the quality of the steel sheet, such as press-molding rawness and freshness after painting.

[0051]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of equipment for adjusting the surface roughness of the steel sheet 1 by a plurality of gas blast nozzles 3a and 3b while continuously conveying the steel sheet 1. As the steel sheet 1, a cold rolled steel sheet, a galvanized steel sheet, or the like is used. In the case of a cold rolled steel sheet, it is desirable that cold rolling, continuous annealing, and temper rolling be performed to adjust mechanical properties.

Further, in the case of imparting surface roughness to the hot-dip galvanized steel sheet, it is suitable to carry out cold rolling, annealing, plating, and temper rolling. However, it is also possible to pass through this line before applying temper rolling to impart surface roughness, and then to temper rolling. Further, the steel sheet 1 is not limited to the cold rolled steel sheet or the galvanized steel sheet, and other surface-treated steel sheets may be used.

FIG. 1 shows a form in which a steel plate is loaded into a payoff reel 17 and wound by a tension reel 18. At this time, the steel plate is continuously conveyed in a state where tension is applied between the entrance-side bridle roll 11 and the exit-side bridle roll 13.

The gas blast nozzles 3a and 3b are arranged in a blast chamber surrounded by a chamber. The particles projected from the gas type blast nozzles 3 a and 3 b are collected in the blast chamber and transferred to the classifier 6. The particles from which foreign substances, crushed particles, etc. have been removed by the classifier 6 are passed through the solid particle supply device 5 to the gas blast nozzles 3 a, 3
sent to b. Although not shown in the figure, the dust or the like selected by the classifier is sent to the dust collector for dust collection processing. A surface roughness measuring device 15 is arranged on the downstream side of the blast chamber, and the surface roughness distribution in the plate width direction is detected by scanning the steel plate in the plate width direction.

On the other hand, the compressed gas generated by the compressor 9 is supplied to the gas type blast nozzles 3a, 3b, and the pressure regulator 8 is arranged in the middle thereof.

In the present embodiment shown in FIG. 1, the solid particles are projected only on the upper surface of the steel sheet 1, but a gas blast nozzle is also arranged on the lower surface of the steel sheet 1 so that the steel sheet is You may adjust the surface roughness of both surfaces. In that case, it is desirable to arrange the surface roughness measuring device also on the lower surface side.

FIG. 3 shows the gas blast nozzles 3a and 3b.
It is a figure showing the structure of. In the figure, 45 is a gas injection nozzle, 46 is a solid particle guide tube, and 47 is a main nozzle. The compressed gas supplied from the pressure regulator is supplied to the gas injection nozzle 45 and is accelerated in the tapered nozzle. On the other hand, the solid particles are sent to the solid particle guide pipe 46 through the supply amount adjuster, are attracted by the air flow injected from the gas injection nozzle 45, and are injected toward the steel plate 1 from the main nozzle 47. Here, the above gas injection nozzle 4
The solid particle guide tube 46 and the main nozzle 47 are collectively referred to as a gas blast nozzle.

The shape of the main nozzle may be a rectangular nozzle or a circular tube nozzle. Generally, a circular tube nozzle is used, and the inner diameter of the gas injection nozzle is about 3 to 12 mm. Further, the inner diameter of the main nozzle 47 is larger than that and about 5 to 20 mm is used.

The pressure of the compressed gas supplied to the gas injection nozzle is about 0.1 to 0.9 MPa, and the projection speed of the solid particles can be changed by adjusting the pressure of the compressed air with the pressure regulator. .

FIG. 2 shows an example of equipment using the above-mentioned gas type blast nozzle as equipment showing the embodiment of the present invention. FIG. 2 shows four gas blast nozzles 23a.
˜23d as one set, and the compressed gas generated by the compressor 21 is sent to each of the gas blast nozzles 23a to 23d through the pressure regulator 22. In the embodiment of the present invention, the gas blast nozzles 23a to 23a are used.
It is assumed that the pressure of the compressed gas sent to 3d is not adjusted individually, but is adjusted so that the pressure is the same.

Also, the gas blast nozzles 23a-23
The solid particles are supplied to the d from the storage tank 24, and solid particle supply amount adjusters 25a to 25d are installed in order to adjust the supply amount of the solid particles to the gas blast nozzles 23a to 23d. . The solid particle supply amount adjusters 25a to 25d may be of a type that can adjust the gate opening inside the particle pipe, and can adjust the amount of solid particles passing through according to the gate opening. With this, it is possible to individually adjust the solid particle supply amount of each of the gas blast nozzles 23a to 23d, and it is possible to adjust each supply amount based on the distribution of the surface roughness of the steel sheet.

Here, the gas blast nozzles 23a to 2
3d is installed as a unit on a lifting frame 28,
The structure is such that the distance between the gas blast nozzles 23a to 23d and the steel plate 1 can be adjusted by the lifting devices 27a and 27b. A suitable distance between the gas blast nozzles 23a to 23d and the steel plate 1 is about 50 to 500 mm. This is because if the gas blast nozzles 23a to 23d and the steel plate 1 are too close to each other, the solid particles reflected on the steel plate surface collide with the gas blast nozzle, and the gas blast nozzle is easily damaged. Further, the gas type blast nozzle 23a-
This is because if the distance between 23d and the steel sheet 1 is too large, the solid particles are decelerated in the air until they collide with the steel sheet, and the solid particles do not collide with each other at a speed sufficient to make an indentation on the surface of the steel sheet.

Further, in the present embodiment, the gas blast nozzles 23a to 23d are integrally provided with the shift device 26 that slides in the plate width direction of the steel plate. This is to change the solid particle projection position on the surface of the steel plate, and by arranging a similar set of gas blast nozzles in the longitudinal direction of the steel plate 1, changing the distance between adjacent gas blast nozzles. Will be possible.

FIG. 5 schematically shows this state. FIG. 5: is a gas-type blast nozzle 23a shown in FIG.
With 23d as one set, eight sets of gas blast nozzles are arranged in the longitudinal direction of the steel sheet 1 while being slightly shifted in the steel sheet width direction to cover the entire sheet width direction of the steel sheet. It shows the arrangement viewed from. The gas blast nozzle sets 31 to 38 each have the mechanism shown in FIG.

Here, the gas blast nozzle set 31
Since ~ 38 can be independently shifted in the plate width direction, a part of the gas type blast nozzle set is overlapped with the projection area and another gas type blast nozzle set is arranged, and the size of the wrap portion is increased. Will be able to change.

For example, the gas blast nozzle set 31
The surface roughness of the steel plate surface given in step 1 is given to the regions corresponding to the individual gas blast nozzles. At this time, a region to which surface roughness is not applied is generated between the gas blast nozzles, and therefore the gas blast nozzle set 32 is arranged so as to project the solid particles to the region.
However, if the wrap portion of the projection range by the gas blast nozzle set 31 and the projection range by the gas blast nozzle set 32 is not appropriate, the surface roughness of that portion becomes uneven, so that it should be made uniform. Then, the gas blast nozzle set 32 is shifted to adjust the size of the lap portion.

In addition, another gas blast nozzle set 3
Similarly, 3 to 38 are shifted in the plate width direction so as to cancel the unevenness of the surface roughness generated on the upstream side. In addition,
In this embodiment, eight gas type blast nozzle sets are used, but a gas type blast nozzle set with some margin is provided as compared with the number of gas type blast nozzles corresponding to the plate width to be processed. It is desirable to place them. This is because the surface roughness of the steel sheet may not be uniformized unless a sufficiently large lap portion is set.

As an embodiment of the present invention, FIG.
It is not necessary to have a mechanism that shifts the gas blast nozzles as a unit, as described above, but in order to increase the degree of freedom of adjustment, a shift mechanism that individually shifts the gas blast nozzles is more effective. You can The optimum device configuration may be selected in consideration of the facility cost. The same applies to the case where the pressure of the compressed air for the gas blast nozzle can be adjusted individually for each nozzle.

[0069]

EXAMPLE As an example of the present invention, the result of applying surface roughness to the surface of a hot-dip galvanized steel sheet by using a plurality of gas blast nozzles will be described.

The steel plate to which surface roughness is applied has a plate thickness of 0.8 mm,
A cold-rolled steel sheet having a plate width of 300 mm was used as a base, and a galvanized film was a hot-dip galvanized steel sheet mainly composed of η phase. After hot-dip galvanizing, a material having a 0.8% elongation ratio by temper rolling was used.

The projected solid particles are SUS having an average particle size of 85 μm.
304 solid particles. These are substantially spherical particles produced by the gas atomizing method, and exert excellent press formability by providing dimple-like microscopic unevenness on the surface of the steel sheet.

A circular nozzle of the type shown in FIG. 3 is used as the gas blast nozzle, and the diameter of the air injection nozzle is 4 mm and the diameter of the main nozzle is 9 mm. In this embodiment, as shown in FIG. 6, five gas blast nozzle sets 51 are arranged on the upstream side and four gas blast nozzle sets 52 are arranged on the downstream side. At this time, each gas blast nozzle is fixed at an interval of 70 mm, and the gas blast nozzle set 52 on the downstream side is staggered with respect to the projection range of the solid particles by the gas blast nozzle set 51 on the upstream side. It is arranged. Further, the pressure of the compressed gas to each of the nozzles 53a to 53e of the gas blast nozzle set 51 can be adjusted only to the same, and the supply amount of the solid particles to each of the nozzles 53a to 53e is 53a corresponding to the plate end and 53e can be adjusted individually, and 53b to 53d in the central portion of the plate width can be adjusted only with the same supply amount.

On the other hand, the pressure of the compressed gas to each of the nozzles 54a to 54d of the gas blast nozzle set 52 can be adjusted to be the same, and the supply amount of the solid particles to each of the nozzles 54a to 54d can be adjusted individually for each nozzle. I am trying. However, the pressures of the compressed gas of the gas blast nozzle set 51 and the gas blast nozzle set 52 can be set to different values for each set.
It is connected to a separate compressor. Also, the distance between each gas blast nozzle and the steel plate is 200 mm.
Is constant and there is no lifting device.

Using the steel sheet surface treating apparatus as described above, a galvanized steel sheet having a width of 300 mm is continuously conveyed,
The surface roughness distribution in the plate width direction was measured. The pressure of the compressed gas in the gas blast nozzle set 51 was kept constant at 0.4 MPa, and the pressure of the compressed gas in the gas blast nozzle set 52 was changed.

The measurement results are shown in FIG. FIG. 7 shows the case where the projection of the solid particles from the gas blast nozzle set 52 on the downstream side is stopped, and the pressure of the compressed gas is 0.2, 0.35,
The distribution of roughness in the plate width direction is shown when the pressure is changed to 0.4 MPa. When the projection of the solid particles from the gas blast nozzle set 52 is stopped, the average roughness imparted to the steel plate surface is small near the central portion between the nozzles. On the other hand, the pressure in the gas blast nozzle set 52 is set to 0.
When the pressure is 2 MPa, the average roughness of the portion where the microscopic unevenness is not provided on the upstream side does not increase so much. On the other hand, when the pressure in the gas blast nozzle set 52 is the same as the pressure in the gas blast nozzle set 51 on the upstream side and is 0.4 MPa, once the surface roughness is provided on the upstream side. However, since there is a region where the solid particles are projected on the downstream side, the average roughness in such a region becomes higher than in other regions, and it was observed as linear unevenness on the surface of the steel sheet.

Therefore, the gas blast nozzle set 52
When the pressure is adjusted to 0.35 MPa, the average roughness in the lap portion of the projection range of solid particles does not become extremely high, and a uniform and even steel plate is obtained over the entire plate width direction. ing.

When the steel sheet has a corrugated shape such as an ear wave, the average roughness at the edge of the sheet may be lower than the others. In such a case, it is desirable to increase the solid particle supply amount of the nozzle 53a or 53e of the gas blast nozzle set 51.

[0078]

As described above, according to the present invention,
Even if multiple gas blast nozzles are used, uniform treatment can be performed, and efficient surface treatment equipment and surface treatment method for steel sheet, and further production of steel sheet using this surface treatment method for steel sheet A method can be provided.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an overall view of a surface treatment facility for steel sheets, which is an example of an embodiment of the present invention.

FIG. 2 is a diagram showing an example of equipment using a gas blast nozzle, which is an embodiment of the present invention.

FIG. 3 is a view showing a structure of a gas blast nozzle.

FIG. 4 is a view showing a state in which a plurality of gas type blast nozzles are wrapped and used.

FIG. 5 is a diagram showing an example of arrangement of gas blast nozzles.

FIG. 6 is a layout view of a gas blast nozzle used in an example of the present invention.

FIG. 7 is a diagram showing a surface roughness distribution in the plate width direction of a steel plate according to an example of the present invention.

[Explanation of reference numerals] 1: Steel plate, 2: Projection chamber, 3a, 3b: Centrifugal projection device,
5: Solid particle supply device, 6: Classifier, 7: Air purge nozzle, 8: Pressure regulator, 9: Compressor, 11, 1
3: Bridle roll, 14: Inspection table, 15: Surface roughness measuring machine, 17: Payoff reel, 18: Tension reel, 21: Compressor, 22: Pressure adjuster, 23a
-23d: Gaseous blast nozzle, 24: Storage tank, 25a-25d: Solid particle supply amount regulator, 26:
Shift device, 27a, 27b: lifting device, 28: frame, 31-38: gas blast nozzle set, 41,
42: gas blast nozzle, 45: gas injection nozzle,
46: Solid particle guide tube, 47: Main nozzle, 51, 5
2: Gas type blast nozzle set, 53a to 53e: Gas type blast nozzle, 54a to 54d: Gas type blast nozzle

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasuhiro Soya             1-2-1, Marunouchi, Chiyoda-ku, Tokyo             Main Steel Pipe Co., Ltd.

Claims (6)

[Claims] 1. A plurality of gas type blast nozzles for injecting solid particles having an average particle diameter of 300 μm or less are arranged in the plate width direction of a continuously conveyed metal plate, individually or for each preset combination, A surface treatment equipment for a metal plate, comprising a projection condition adjusting device for adjusting the injection condition of solid particles from each nozzle. 2. A plurality of gas blast nozzles for injecting solid particles having an average particle diameter of 300 μm or less are arranged in the plate width direction of a continuously conveyed metal plate, and the solid particles are arranged according to the plate width of the metal plate. A surface treatment method for a metal plate, which has a function of changing a gas blast nozzle for injecting the gas. 3. A metal plate surface treatment facility in which a plurality of gas blast nozzles for injecting solid particles having an average particle diameter of 300 μm or less are arranged in the plate width direction of a continuously conveyed metal plate is used, It is characterized by measuring the surface morphology of the metal plate after projecting the particles, and adjusting the injection conditions of the gas type blast nozzle for injecting the solid particles individually or for each preset combination based on the actual measurement value. Surface treatment method for metal plate. 4. The surface treatment method for a metal plate according to claim 3, wherein the surface morphology is an average roughness Ra and a maximum roughness R.
max, ten-point average roughness Rz, root mean square roughness Rq, peak count PPI, average mountain interval Sm, center waviness Wca,
A surface treatment method for a metal plate, which is represented by one or a plurality of parameters among the coverage of dimples formed by solid particles. 5. The method for surface treatment of a metal plate according to claim 3, wherein the gas blast nozzle for injecting the solid particles has a pressure of compressed gas, a supply amount of the solid particles, A surface treatment method for a metal plate, wherein the condition is one or more of the distance between adjacent gas blast nozzles and the distance between the nozzle and the metal plate. 6. Any one of claims 2 to 5
A method for manufacturing a metal plate, comprising the method for surface treatment of a metal plate according to the item 1) in a manufacturing process thereof.