JP2005211944A - Press molding material and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material for press molding made of a metal plate which is formed in an optimal friction state at a necessary part in press molding and has good formability and shape freezing property.
An inner portion 11 of a circular blank corresponding to a deep drawing punch diameter φ50 mm remains in a microscopic uneven state of a base material, and other portions 12 (shaded portions) have dimples. The microscopic unevenness of the shape is given. Since the portion 12 subjected to deep drawing is provided with dimple-like micro unevenness, the oil retaining property of this portion is increased and the friction coefficient is decreased. Therefore, in the press, the friction coefficient of the die face portion can be increased, the friction coefficient of the punch surface can be decreased, the spring back can be reduced, and the shape freezing property can be improved.
[Selection] Figure 2

Description

  The present invention relates to a press-molding material made of a metal plate and having excellent press-formability, and a method for producing the same.

  For metal plates such as cold rolled steel plates, galvanized steel plates, and stainless steel plates, it is necessary to appropriately adjust the surface roughness of the metal plates from the viewpoint of press formability and the like. One of the objects is to improve the oil retaining property between the metal mold and the metal plate during press molding by adjusting the surface roughness of the metal plate, and to obtain good press moldability.

  In order to adjust the surface roughness of such a metal plate, a means for imparting certain microscopic irregularities to the surface of the rolling roll and transferring the irregularities in the temper rolling process is used (for example, JP-A-8-33902 (Patent Document 1)). This is a surface that imparts certain microscopic irregularities to the roll of temper rolling and transfers it to the entire surface of the metal plate, and keeps the sliding characteristics with the mold constant during press molding. It is intended to give roughness.

  On the other hand, from the viewpoint of press formability, it is generally desirable to improve oil retention and reduce the friction coefficient of the sliding surface. However, depending on the target member, improving lubricity is not necessarily the optimal condition. There may not be.

  For example, in deep drawing, increasing the lubricity of the die face surface reduces the drawing resistance and improves the forming limit.However, increasing the lubricity of the punch surface reduces the friction resistance of the punch shoulder, that is, the fracture resistance. In some cases, the forming limit may be lowered (translation of five bows, basics of plastic working, p.363, 1972, Corona (non-patent document 1)). Actually, if the lubricity of the die face and punch surface is improved, the effect on the die face is relatively greater than the effect on the punch surface, so that overall deep drawability is improved. However, ideally, it is desirable to control the coefficient of friction to an appropriate value depending on the molding mode and the contact area with the mold.

  In press forming of high-strength steel sheets, the demand for which is increasing mainly in automobile applications in recent years, the shape freezing property is an important factor, but the friction coefficient of the punch surface is increased while the friction coefficient of the die face surface is increased. It is also known that the reduction reduces the springback and improves the shape freezing property.

  Therefore, steel plates used for press forming are not necessarily ideal because of their low sliding resistance and low coefficient of friction throughout the entire surface, and even in the same metal plate surface, they can be placed in contact with the press style or mold. Accordingly, appropriately adjusting the friction coefficient is one of the means for improving the press formability.

Japanese Patent Laid-Open No. 8-33902 Five bow translation, Basics of plastic working, p.363, 1972, Corona

  However, in the conventional method of imparting surface roughness by temper rolling, although certain microscopic irregularities can be imparted to the entire surface of the metal plate, only the necessary place in the plane of the metal plate is different. The surface roughness cannot be adjusted, and the coefficient of friction cannot be adjusted according to the press style or the position of contact with the mold.

  Of course, it is conceivable to change the microscopic unevenness imparted to the roll in the circumferential direction of the temper rolling roll, and to transfer this to a metal plate. However, the surface roughness is adjusted at a pitch corresponding to the circumference of the roll diameter. The distribution can only be given, and the surface roughness cannot be adjusted according to the target member for press molding. It is also possible to change the microscopic uneven state in the roll length direction of the roll, but it is only possible to change the surface roughness at a specific position in the width direction of the metal plate, and the metal having different plate widths. It cannot cope with a board.

  On the other hand, it is conceivable to apply different lubricating oils according to the position of contact with the mold during press molding, and adjust the friction state during press molding. However, it spreads to the periphery due to the fluid characteristics of the lubricating oil, and variations in the way of flow cause variations in the press formability itself. In addition, when a high-viscosity lubricating oil is applied in order to improve lubricity, the degreasing property is deteriorated in the subsequent degreasing process, and there is a problem that the waste liquid treatment becomes difficult and the working environment is deteriorated.

  As described above, in the press forming of metal plates, ideally, it is desirable to control the friction coefficient appropriately according to the press style and the contact position with the mold, but the surface roughness is reduced by temper rolling as in the past. Such adjustment is difficult by a method of applying or a method of applying a partially different lubricating oil.

  The present invention has been made in view of such circumstances, and an optimum friction state is formed at a necessary portion in press forming, and the press forming is made of a metal plate having good formability and shape freezing property. It is an object to provide a material and a manufacturing method thereof.

  A first means for solving the above-mentioned problem is a press-molding material (Claim 1) characterized in that a specific range of the surface is made of a metal plate having a dimple-like microscopic form. .

  According to this means, by adjusting the microscopic form of the surface of the metal plate according to the part that contacts the mold during press molding, the oil retention of the interface with the mold between that part and the other part And the coefficient of friction can be controlled. In particular, the oil retention of the part can be improved by making the part which should reduce a friction coefficient and improve slidability into a dimple-like form by projection of a solid particle.

  Metal plates targeted by the present invention include steel materials such as hot-rolled steel plates, cold-rolled steel plates, surface-treated steel plates and stainless steel plates, and non-ferrous metal plates such as aluminum, copper and magnesium. This is because these are metal plates used for press molding.

  Here, the dimple shape is a form in which the shape of the dent on the surface is mainly composed of a curved surface, and for example, many crater-like dents formed by collision of a spherical object with the surface are formed. By forming a large number of dimple-shaped dents, the dents can act as oil pockets in press molding, improving oil retention between the mold and the metal plate, and applying pressure. When sliding in a wet state, oil flows out from the recess, and an effect of reducing the friction coefficient of the contact interface occurs.

  Note that, as in the prior art, the uneven state obtained by a method in which the rolling roll is subjected to discharge dull processing, shot processing, electron beam processing or laser processing, and the microscopic unevenness is transferred to a metal plate is the present invention. This does not correspond to the “dimple-like” microscopic form. This is because it is difficult to adjust the coefficient of friction with other parts to a different value because the effect of retaining oil in the recess is small.

  For example, in the method of imparting unevenness to a rolling roll and transferring it to a metal plate, the various means basically form a plurality of recesses on the surface of the rolling roll, so that the portion to be transferred to the metal plate Is mainly composed of convex portions remaining without forming discharge traces or shot traces on the surface of the rolling roll.

  Normally, electrical discharge machining, shot machining, electron beam machining, discharge traces by laser machining, shot traces, and laser traces can in principle form dimple-shaped recesses, but metal plates can Since the portion other than the formed recess is transferred as the recess, it is difficult to form the dimple-like recess in the metal plate.

  In that case, the shape of the recessed portion to be formed is such that the ridge line portion of the portion pushed into the metal plate does not have a circular shape or an elliptical shape, and when the concave portion is viewed from the upper surface of the metal plate, like a cloud ruler Since the shape is such that a plurality of large dimples are connected, the oil retained at the interface is likely to flow out in a specific direction. As a result, the oil retaining property at the interface is lowered as compared with the form of the dimple-shaped recess.

  In other words, whether or not it is “dimple-like” is formed by a curved line that is closed to some extent isotropic, with the ridge line of the recess being circular or elliptical when the microscopic form is observed from the upper surface of the metal plate. It can be determined by whether or not it is, and individual projections such as a cloud ruler, which are obtained by the prior art, do not include a shape that is not isotropic, so that a unique effect of this means can be exhibited. .

  By the way, in this means, a specific range of the metal plate is made into a dimple-like microscopic form, and the “specific range” is adjusted to a small friction coefficient that is different from other parts in press forming. This is a power range, particularly a range where the friction coefficient should be reduced. For example, in deep drawing, the range is in contact with the die face during molding. By imparting a dimple-like microscopic form to this portion, the coefficient of friction on the die face surface can be reduced, and the required deformation force can be reduced. At the same time, if the punch surface and its R portion are not changed in surface form and the friction coefficient is not lowered, it is possible to achieve both high transmission force and improve the limit drawing ratio (non- Patent Document 1).

  On the other hand, for press molding requiring shape freezing, the “specific range” corresponds to a range corresponding to the punch surface. By imparting a dimple-like microscopic form to this part, the slidability on the punch surface is improved compared to the slidability on the die face surface, and the tension applied to the metal plate to be formed is increased. As a result, the spring back can be reduced.

  As described above, the “specific range” is a range in which the friction coefficient at the time of press molding is desired to be smaller than that of other parts in correspondence with the molding mode in press molding. Therefore, if it is required to improve the properties required for press molding, such as crack limit, wrinkle limit, shape freezing property, etc. for a specific part, this part should be designated as “specific range”. That's fine. Therefore, this means also includes the one in which a dimple-like microscopic form is provided only on one side of the metal plate. For example, in deep drawing, by applying a dimple-like microscopic form to the entire surface of the metal plate only on the surface not in contact with the punch surface, and reducing the friction coefficient only on the surface, the drawability is reduced. Can be improved.

  By the way, about the surface form of the part which does not give the dimple-like microscopic form to the metal plate, the form obtained by the transfer by the rolling roll as in the prior art may be used, and the part with the dull eye or bright surface Is used. As a processing method of the rolling roll, various dull surface processing methods such as shot blasting, electric discharge processing, electron beam processing, laser processing, and grinding / polishing are usually used.

  The second means for solving the above-mentioned problem is the first means, wherein the dimple-like microscopic form is a dent when the dimple-like dent is viewed from the surface of the metal plate. The diameter of the smallest circle including the diameter is 5 to 200 μm, and the depth of the recess is 0.3 to 50 μm (Claim 2).

  It is desirable that the dimple as a microscopic form has a dent depth of 0.3 to 50 μm, usually 10 μm or less. This is because if the recess is shallow, the oil retaining property in the recess is lowered. On the other hand, if the depth is too deep, the oil will only accumulate at the bottom of the recess, and the recess will not be filled with oil, so oil will not flow out to the surroundings when contacting the mold, and oil will not be supplied to the contact. This is because the effect of lowering the friction coefficient is reduced.

  On the other hand, the size of the dimple-like dent when viewed from the surface of the metal plate is preferably 5 to 200 μm in diameter, and particularly preferably 5 to 50 μm. This is because if the diameter of the dimple-shaped recess is less than 5 μm, the amount of oil retained in the recess is reduced and the oil retention cannot be improved. Conversely, if it exceeds 200 μm, the oil applied to the metal plate This is because there is a case where the amount of is too small compared to the volume of the recess, and the friction coefficient may increase if the recess is not filled with oil.

  However, the dimple shape may not be a perfect circle when viewed from the upper surface of the metal plate, and may be an elliptical shape or a polygonal shape. This is because the same effect is exhibited if the shape is such that the oil is easily retained as the recess. In this case, the diameter of the smallest circle including the recess is preferably 5 to 200 μm, and particularly preferably 5 to 50 μm.

  A third means for solving the above-mentioned problem is a method for producing a press forming material which is the first means or the second means, and projects solid particles only on a specific range of the surface of the metal plate. Thus, a dimple-like microscopic form is imparted (claim 3).

  By projecting the solid particles onto the surface of the metal plate, the kinetic energy is converted into the indentation work on the surface of the metal plate, and indentations (indentations) are generated on the surface. The indentation at this time becomes smaller as the particle diameter of the solid particles is smaller, and a minute recess is 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, thereby forming dimple-like microscopic irregularities that are dense and have a very short interval between the indentations.

  By giving such a dimple-like microscopic form only to a specific range of the metal plate, the oil retention between the mold and the metal plate at that part is improved, and the sliding characteristics are improved. Can do.

  Here, the size of the solid particles to be projected is preferably an average particle size of 30 to 300 μm. This is because the friction coefficient during press forming can be further reduced by densely providing short pitch irregularities on the steel sheet surface.

  As the solid particle projection means, a centrifugal rotor type projection device or a pneumatic projection device can be used. The pneumatic projection device accelerates solid particles by accelerating compressed air using an injection nozzle and utilizing the drag force. In particular, it is suitable for projection of fine particles having a small mass of solid particles, and is characterized in that the particle velocity can be greatly increased. On the other hand, the centrifugal rotor type projection device projects solid particles using centrifugal force generated by rotating vanes, and can secure a large projection amount as compared with the pneumatic type projection device. It is suitable for high-speed processing.

  Examples of the solid particles to be projected include steel balls, steel grids, stainless steel, high speed steel, alumina, silicon oxide, diamond, zirconia oxide, tungsten carbide, and the like. However, particles that are difficult to crush, such as metal-based solid particles, are desirable because they impinge on the surface with a dimple-like impression by colliding with a metal plate.

  The 4th means for solving the above-mentioned subject is the above-mentioned 3rd means, and the method of projecting a solid particle only to the specific range of a metal plate surface is a metal plate and solid particles conveyed continuously Characterized in that a shielding object divided in the width direction of the metal plate is provided between the projection device and the position of the divided piece of the shielding object in accordance with the conveyance of the metal plate. (Claim 4).

  In this means, it is a processing method for a metal plate that is continuously conveyed, and a part or all of a region (hereinafter referred to as “projection region”) in which solid particles collide with the metal plate in a state where there is no shielding object, By shielding with the divided pieces of the shielding object, the surface form of the base material remains as it is in the shielded part, and a dimple-like microscopic form is given to the metal plate in the unshielded part.

  In other words, by adjusting the position of the shield according to the progress of the metal plate, it is possible to separate the part to which the dimple-like microscopic form is given from the base material part, and in the press molding, the dimple-like fine part is formed. The solid particles collide only in a “specific range” to which a visual form is to be imparted.

  Therefore, a range in which a dimple-like microscopic form should be given to the metal plate is set in advance so that the solid particles do not collide with the metal plate at the portion where the dimple is not given in accordance with the traveling speed of the metal plate. The dimple-like microscopic form is given to any area on the surface of the metal plate by adjusting the position of the shielding object and retracting the shielding object to a position where the projection area is not shielded. can do.

  It is structurally simple to use a flat plate as the shield, but it may have a three-dimensional structure. However, since solid particles may always collide, it is desirable that the material has excellent wear resistance. Furthermore, it is necessary to provide rigidity that does not cause deflection or the like even when solid particles collide.

  The shielding object between the projection device and the metal plate can be placed at any position as long as it can shield particles that collide with the metal plate. It is desirable to install it at a position more than 10mm away from the metal plate.

  In addition, as a structure of a shield, it is comprised by the some shield divided | segmented in the plate width direction of the metal plate, and slides the shield corresponding to each position of a plate width direction, and adjusts a shielding area | region. A structure is desirable. Further, when the shape of the range to which the dimples are applied is complicated, it is necessary to increase the number of divisions of the shielding object so as to make the adjustment possible with a higher degree of freedom.

  As described above, according to the present invention, an optimum friction state is formed in a necessary part in press molding, and a press molding material made of a metal plate having good formability and shape freezing property, and its A manufacturing method can be provided.

  Hereinafter, an example of a method for producing a material for press molding, which is an embodiment of the present invention, will be described. This example is an example in which a dimple-like microscopic form is imparted to the surface of a steel plate using a centrifugal rotor type projection device. FIG. 5 is a schematic view of a centrifugal rotor type projector. The centrifugal rotor type projection device is a device that accelerates solid particles by utilizing centrifugal force by means of an impeller 22 and a vane 23 driven by a motor 21 (an impeller 22, a vane 23, and a part that rotates incidentally is a “centrifugal rotor”). It is said). The solid particles are supplied from the state stored in the tank or the like to the central portion of the impeller 22 of the centrifugal rotor type projector through the particle supply pipe 24. In general, the vane portion of the centrifugal rotor projector has an outer diameter of about 300 to 500 mm. At this time, when the distance from the rotor rotation center to the steel plate 25 is large, the solid particles to be projected are small, and the deceleration in the air is large. Therefore, the projection distance is used for the embodiment of the present invention. Is preferably 700 mm or less.

  FIG. 1 is a view showing a method of manufacturing a press-molding metal plate according to an embodiment of the present invention when such a centrifugal rotor type projection device is used. (A) has shown the case where the centrifugal rotor type | mold projection apparatus 2 is seen from the side surface, (b) shows the state which the projection area | region 3 spreads perpendicularly with respect to the advancing direction of the metal plate 1 in the projection area | region 3. Show. Moreover, the shielding board 4 is arrange | positioned between the projection apparatus and the metal plate, and the shielding board 4 is divided into plurality by the board width direction.

  The shielding plate 4 has a mechanism in which the divided pieces in the plate width direction individually slide in the front-rear direction (length direction of the metal plate 1), and shields all or part of the corresponding projection region 3. Can do. Since the solid particles do not collide with the metal plate 1 in the portion where the divided pieces of the shielding plate 4 exist, the portion does not give dimples, and the dimples are given to the metal plate 1 at the position where the divided pieces of the shielding plate 4 are retracted. Will be.

  Therefore, by sliding each of the divided pieces of the shielding plate 4 according to the progress of the metal plate 1, it is possible to form a portion on the surface of the metal plate 1 that has been dimpled and a portion that does not.

  In FIG. 1, the shielding plate 4 is inserted into the projection region from the downstream side of the metal plate 1, but the same effect can be obtained even if it is installed from the upstream side of the metal plate 1. Moreover, although the shielding board 4 is installed only in the upper surface of the steel plate in the figure, the same means can be applied also when projecting the lower surface side.

  Furthermore, for the metal plate 1 having a wide plate width, a plurality of centrifugal rotor type projection devices 2 are arranged in the plate width direction, and the shielding plate 4 is arranged in a projection region by each centrifugal rotor type projection device 2. By doing so, the same processing can be performed for the metal plate 1 having a wide plate width.

<Example 1> (Confirmation of improvement effect of off-line press formability)
As a first embodiment of the present invention, the result of cylindrical deep drawing applied to a 0.7 mm thick galvanized steel sheet will be described. The material galvanized steel sheet has a plating film mainly composed of η phase, and is subjected to temper rolling after hot dip galvanization. The temper rolling is performed using a rolling roll with irregularities by electric discharge dull processing, and microscopic irregularities with an average roughness Ra of 0.9 μm and a peak count PPI of 175 are given over the entire surface of the base material. did. As described above, the metal plate thus obtained does not have “dimple-like” microscopic irregularities.

  In this example, a blank as shown in FIG. 2 was prepared, and cylindrical deep drawing was performed. This is a circular blank having an outer diameter of 105 mm, and the inner portion 11 corresponding to the deep drawing punch diameter φ50 mm remains in the microscopic uneven state of the base material, and the other portion 12 (shaded portion) ) Is provided with dimple-like microscopic unevenness.

  The dimple-like portion 12 having microscopic irregularities has an average roughness Ra of 1.1 μm and a PPI of 375, and is projected by projecting substantially spherical SUS304 solid particles having an average particle diameter of 85 μm. Was granted. When projecting the solid particles, a shield was provided so that the solid particles did not collide only in the portion corresponding to the punch diameter. Thus, dimple-like microscopic unevenness is imparted to the outer peripheral side portion 12 on which the solid particles collide, and the surface form of the base material remains on the inner portion 11.

As solid particle projection conditions, a solid particle is projected from a nozzle under a condition of air pressure of 0.3 MPa by a pneumatic projection device, and the projection amount per cross-sectional area of the steel sheet is 5 kg / m ² .

  Cylindrical deep drawing was performed using the blank thus prepared. As a comparative example, a sample having the same size as the blank of FIG. 2 and the entire surface remaining in the surface form of the base material and a sample provided with dimple-like microscopic unevenness on the entire surface under the same conditions as described above were prepared. Then, cylindrical deep drawing was performed under the same conditions.

Cylindrical deep drawing was performed using a tool having a punch diameter of φ50 mm and a die size of φ53 mm, and Preton R352L manufactured by Sugimura Chemical Co. or Ferrocoat 6130 manufactured by Quaker Chemical Co. was used as a lubricating oil. At this time, the forming test was carried out by changing the wrinkle pressing force, and the press formability was evaluated by the limit wrinkle pressing force at which cracking occurs in the steel sheet. Table 1 shows the test results.
(Table 1)

  As can be seen from Table 1, in any case where any lubricating oil is used, when the microscopic unevenness is given to the entire surface by temper rolling of the prior art and the entire surface is dimple-like microscopic unevenness by projection of solid particles. Compared with the case of giving, the crack limit wrinkle pressing force is larger in the present example in which dimple-like micro unevenness is given only in a specific range. This is because the dimple-like micro unevenness is given only in a specific range, so that the friction coefficient on the punch face and its R part is not lowered while lowering the friction coefficient on the die face surface. The cracking limit is expanded by improving the forming limit and decreasing the breaking resistance.

In the blank shown in FIG. 2, it is not necessary to make the range where the dimple-like microscopic unevenness is not given the same range as the portion corresponding to the punch diameter, and it should match the range where the punch comes into contact to some extent. That's fine. Further, in this example, dimple-like micro unevenness was given to almost the same range of both sides of the blank, but the entire surface on the side not in contact with the punch remained as a base material or dimple-like micro unevenness. Even if it is provided, the same effect can be obtained.
<Example 2>
As a second embodiment of the present invention, the results of applying pyramidal drawing to a cold rolled steel sheet having a thickness of 0.8 mm will be described. The cold-rolled steel sheet is subjected to temper rolling with a rolling roll provided with irregularities by shot dull processing, so that the average roughness Ra is 0.9 μm and the peak count PPI is 120 over the entire surface of the base material. Visual irregularities were added.

  In a present Example, with respect to the cold-rolled steel plate conveyed continuously, the cold-rolled steel plate which has a surface roughness as shown in FIG. 3 by the method which combined the shielding board with the mechanical projection apparatus shown in FIG. Manufactured. The hatched portion 13 in the figure is a portion to which dimple-like microscopic unevenness is given by the collision of solid particles, and the other portion 14 is left with a microscopic form given by temper rolling as a base material. Represents the part. This is because the shielding plate 4 is positioned in the projection area at the timing when the portion where the solid particles do not collide reaches the position of the projection device in advance, so that the solid particles do not collide, and the shielding plate is reached when the portion finishes passing. 4 is manufactured by repeating the operation of retracting 4.

  In this example, the cold-rolled steel sheet produced in this way was cut, and a blank as shown in FIG. 4 was created to perform pyramid drawing. In this blank, the portion 14 in contact with the punch having a side length of 200 mm remains in the microscopic uneven state of the base material, and dimple-like micro unevenness is imparted to the other portion (the hatched portion 13). Has been. The portion 13 provided with dimple-like microscopic unevenness has an average roughness Ra of 1.1 μm and a PPI of 345.

As a tool in the pyramid drawing, a tool having a punch side length of 200 mm, a punch corner radius of 40 mm, and a die piece radius of 5 mm was used, and Daphne SK manufactured by Idemitsu Kosan Co., Ltd. was used as a lubricating oil. At this time, the press formability was evaluated based on the limit forming height at which cracks do not occur. As a comparative example, a sample having the same size as the blank of FIG. 4 and the entire surface being the surface form of the base material, and a sample having dimple-like micro unevenness formed on the entire surface under the same conditions as above were prepared. Thus, pyramidal drawing was performed under the same conditions. Table 2 shows the test results.
(Table 2)

  As can be seen from Table 2, the cold-rolled steel sheet according to the present example is provided with microscopic unevenness on the entire surface by temper rolling according to the prior art and on the entire surface with dimple-like microscopic unevenness by projection of solid particles. Compared to the case, the limit forming height is improved and the press formability is improved.

It is the figure which showed the manufacturing method of the metal plate for press molding which is embodiment of this invention at the time of using a centrifugal rotor type projector. It is a figure which shows the shape of the blank which is the Example of this invention used for Example 1. FIG. It is a figure which shows the manufacturing method of the blank which is the Example of this invention used for Example 2. FIG. It is a figure which shows the shape of the blank which is the Example of this invention used for Example 2. FIG. It is the schematic of a centrifugal rotor type projector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Metal plate, 2 ... Centrifugal rotor type | mold projection apparatus, 3 ... Projection area | region, 4 ... Shielding plate, 11 ... Inner part, 12 ... Parts other than an inner part, 13 ... Dimple-shaped micro unevenness | corrugation , 14 ... Other parts, 21 ... Motor, 22 ... Impeller, 23 ... Vane, 24 ... Particle supply pipe, 25 ... Steel plate

Claims (4)

A material for press molding, characterized in that a specific range of the surface is a metal plate having a dimple-like microscopic form. In the dimple-like microscopic form, when the dimple-like depression is viewed from the surface of the metal plate, the diameter of the smallest circle including the depression is 5 to 200 μm, and the depth of the depression is 0.3. The material for press molding according to claim 1, which is ˜50 μm. The method for producing a material for press molding according to claim 1 or 2, wherein solid particles are projected only on a specific range of the surface of the metal plate to give a dimple-like microscopic form. The method of projecting solid particles only on a specific range of the surface of the metal plate is provided with a shield divided in the width direction of the metal plate between the metal plate continuously transported and the solid particle projection device, 4. The method for manufacturing a press forming material according to claim 3, wherein the method is a method of adjusting the position of the divided piece of the shielding object in accordance with the conveyance of the metal plate.

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