JP2022031207A - Shear processing device and manufacturing method of processed material using the same - Google Patents

Abstract

To disclose a shear processing device which enables reduction of tensile residual stress of a fracture surface of a processed material when a steel material is sheared to obtain the processed material.SOLUTION: A shear processing device includes a first blade and a second blade and is configured so that the first blade and the second blade can move relative to each other. The first blade has a first bottom surface, a first side surface, and a first tip part, and the second blade has a second bottom surface, a second side surface, and a second tip part. A friction coefficient of the first tip part is larger than a friction coefficient of the second tip part.SELECTED DRAWING: Figure 4

Description

The present application discloses a shearing machine and a method of manufacturing a processed material using the shearing machine.

Patent Document 1 discloses a technique for obtaining a processed material by shearing a steel material using a punch and a die. In Patent Document 1, the tensile residual stress of the fracture surface of the processed material is reduced by pressing the fracture surface of the punched material punched against the fracture surface of the processed material.

Patent Document 2 discloses a technique for providing a chromium-based coating layer on a shear cutting tool. According to the technique disclosed in Patent Document 2, peeling of the coating layer of the shear cutting tool is suppressed.

International Publication No. 2016/136909 Japanese Unexamined Patent Publication No. 2011-255386

As disclosed in Patent Document 1, in a processed material obtained by shearing a steel material, the tensile residual stress of the fracture surface may become large. When a processed material is obtained by shearing a steel material, a new technique capable of reducing the tensile residual stress of the fracture surface of the processed material is required.

The present application is one of the means for solving the above problems.
A shearing machine equipped with a first blade and a second blade.
The first blade and the second blade are configured to be relatively movable.
The first blade has a first bottom surface, a first side surface, and a first tip portion.
The second blade has a second bottom surface, a second side surface, and a second tip portion.
The coefficient of friction of the first tip is larger than the coefficient of friction of the second tip.
Disclose the shearing equipment.

In the shearing apparatus of the present disclosure, the friction coefficient of the first tip portion may be 1.5 times or more the friction coefficient of the second tip portion.

In the shearing apparatus of the present disclosure, the friction coefficient of the first tip portion may be 2.0 times or more the friction coefficient of the second tip portion.

In the shearing apparatus of the present disclosure, the second tip portion may be coated with a second coating.

In the shearing apparatus of the present disclosure, the second tip portion may be coated with the second coating, the first tip portion may be coated with the first coating, and the peeling life of the second coating is long. It may be longer than the peeling life of the first coating.

In the shearing apparatus of the present disclosure, the surface roughness of the first tip portion may be larger than the surface roughness of the second tip portion.

The present application is one of the means for solving the above problems.
It is a method of manufacturing a processed material by using the shearing processing apparatus of the present disclosure.
Arranging a steel material between the first blade and the second blade, where the steel material has a first surface and a second surface opposite to the first surface, and the first blade The first bottom surface is in contact with the first surface, the second bottom surface of the second blade is in contact with the second surface, and
Shearing the steel material by relatively moving the first blade and the second blade.
Disclose a method for manufacturing a processed material, including.

In the manufacturing method of the present disclosure, the steel material may be plate-shaped.

In the manufacturing method of the present disclosure, the tensile strength of the steel material may be 980 MPa or more.

In the manufacturing method of the present disclosure, the tensile strength of the steel material may be 1470 MPa or more.

According to the shearing apparatus of the present disclosure, it is possible to manufacture a processed material in which the tensile residual stress of the fracture surface is reduced.

It is a schematic diagram for demonstrating an example of the flow of shearing. (A) shows the state where the steel material is arranged between the first blade and the second blade, and (B) shows the state where the first blade and the second blade are relatively moved and brought closer to each other, so that the first blade Shows a state in which the bottom surface is in contact with the first surface of the steel material and the bottom surface of the second blade is in contact with the second surface of the steel material, and (C) is a state in which a part of the work material is punched out by the first blade. (D) shows a state in which the first blade and the second blade are separated from each other and returned to the position of (A). It is a schematic diagram for demonstrating an example of the formation mechanism of a sheared end face at the time of shearing a steel material. It is a cross section along the relative moving direction of the first blade and the second blade, and shows the form of the cross section including the first blade, the second blade and the steel material. (A) indicates a state in which sagging is formed on the steel material by pressing the first blade and the second blade against the steel material, and (B) further presses the first blade and the second blade against the steel material after the sagging is formed. (C) shows a state in which a crack is generated in the steel material, and (C) shows a state in which a part of the steel material is punched out by further pressing the first blade and the second blade against the steel material. It is a schematic diagram for demonstrating the new knowledge by this inventor. When (A) develops a crack from the first blade, (B) develops a crack from both the first blade and the second blade, and (C) develops a crack from the second blade. Is. “◯” means that the tensile residual stress is small, “Δ” means that the tensile residual stress is medium, and “×” means that the tensile residual stress is large. It is a schematic diagram for demonstrating an example of the structure of the shearing processing apparatus of this disclosure. The cross-sectional shapes of the first blade and the second blade are shown schematically. It is a schematic diagram for demonstrating the "tip portion" of a blade. (A) shows a cross section when R is given to the tip of the blade or when chamfering is not performed, and (B) shows a cross section when R is given to the tip of the blade. There is. It is a schematic diagram for demonstrating an example of the structure of the shearing processing apparatus of this disclosure. The cross-sectional shapes of the first blade and the second blade are shown schematically. (A) is a form in which only the second blade is coated, (B) is a form in which only the first blade is coated, and (C) is a form in which both the first blade and the second blade are coated. It is a form. It is a schematic diagram for demonstrating a shear angle. It is a schematic diagram for demonstrating an example of the structure of the processed material manufactured by the shearing processing apparatus of this disclosure. The cross-sectional shape of the processed material is shown. It is a schematic diagram for demonstrating an example of the structure of the shear end face of the processed material of this disclosure. The state where the shear end face is seen from the front is shown. It is a schematic diagram for demonstrating the method of discriminating the 1st part and the 2nd part in a fracture surface. (A) schematically shows the direction of hydrogen embrittlement cracks generated in the fracture surface, and (B) indicates an arbitrary position X between the sagging side and the burr side in the fracture surface and the direction of hydrogen embrittlement cracks (B). The relationship with the angle θ) is schematically shown.

1. 1. Issues and new findings A processed material having a sheared end face can be obtained, for example, as follows. First, as shown in FIG. 1A, the steel material 5 is arranged between the first blade 21 and the second blade 22. Here, the steel material 5 has a first surface 10a and a second surface 10b opposite to the first surface 10a, and the first blade 21 has a first bottom surface 21a, a first side surface 21b, and a first tip portion 21x ( The second blade 22 has a second bottom surface 22a, a second side surface 22b, and a second tip portion 22x (see FIGS. 2 and 4). As shown in FIG. 1B, the first bottom surface 21a is in contact with the first surface 10a of the steel material 5, and the second bottom surface 22a is in contact with the second surface 10b of the steel material 5. The first blade 21 may be a punch and the second blade 22 may be a die. Subsequently, as shown in FIGS. 1B and 1C, the steel material 5 is sheared by relatively moving the first blade 21 and the second blade 22. As a result, as shown in FIGS. 1C and 1D, a part of the steel material 5 is punched out as scrap 15 by the first blade 21, and the remaining part of the steel material 5 has a sheared end face 1. Can be. The scrap 15 may be used for some products.

FIGS. 1 (A) to 1 (D) show a form in which a shear angle is not provided between the first blade 21 and the second blade 22, but there is a gap between the first blade 21 and the second blade 22. A shear angle may be provided. Further, in FIGS. 1A to 1D, the line of intersection (the tip of the first blade 21) between the first bottom surface 21a of the first blade 21 and the first side surface 21b is in the longitudinal direction of the first blade 21. Although the form of extending linearly toward the blade is shown, the tip of the first blade 21 may extend linearly in the longitudinal direction. That is, the shape of the sheared end surface 1 in a plan view may be sheared so as to be linear, may be sheared so as to be curved, or may be sheared so as to be a combination of linear and curved. You may. Further, FIGS. 1 (A) to 1 (D) show a form in which the end portion of the steel material 5 is sheared and removed by the first blade 21 and the second blade 22, but the first blade 21 and the second blade By shearing the steel material 5 with 22, a punch hole, a slit, or the like may be formed in a part of the steel material 5. In this case as well, the processed material 10 having the sheared end face 1 can be obtained.

An example of the formation mechanism of the shear end face 1 will be described. As shown in FIGS. 2A to 2C, a case where a processed material 10 having a sheared end face 1 is obtained by shearing a steel material 5 with a first blade 21 and a second blade 22 will be considered. As shown in FIG. 2A, the first bottom surface 21a of the first blade 21 is pressed against the first surface 10a of the steel material 5, so that the sagging 1a is formed on the first surface 10a side of the steel material 5. The sagging 1a is formed in the process until the first tip portion 21x of the first blade 21 bites into the steel material 5. After the sagging 1a is formed, the sheared surface 1e (see FIG. 8) may be formed in the process of the first tip portion 21x biting into the steel material 5. As shown in FIG. 2B, after the sagging 1a and the sheared surface 1e are formed, a first crack 1dx is generated from the first blade 21 side toward the second blade 22 side. On the other hand, also on the second blade 22 side, similarly, after the second tip portion 22x bites into the second surface 10b of the steel material 5, the second crack is made from the second blade 22 side toward the first blade 21 side. 1dy is generated. As shown in FIG. 2C, the fracture surface 1b is formed by each of the first crack 1dx and the second crack 1dy extending and joining each other. Further, by further moving the first blade 21 and the second blade 22, the steel material 5 is separated into the scrap 15 and the processed material 10 which is the target object. At this time, as shown in FIG. 2C, a burr 1c may be formed at a corner portion on the second blade 22 side of the sheared end surface 1 of the processed material 10. FIG. 2 regardless of the presence or absence of a shear angle between the first blade 21 and the second blade 22 and the shape of the shear end surface 1 in a plan view (straight, curved or a combination thereof, punch holes, slits, etc.). The shear end face 1 can be formed by a mechanism such as (A) to (C).

In the shear end face 1 formed as described above, compressive residual stress or tensile residual stress may occur due to damage or strain due to shearing. When a large tensile residual stress is present in the shear end face 1, for example, the hydrogen embrittlement resistance or fatigue strength of the shear end face 1 tends to decrease. In this respect, in order to obtain the processed material 10 having high performance, how to reduce the tensile residual stress in the sheared end face 1 can be one of the problems. In particular, as disclosed in Patent Document 1, it is preferable that the tensile residual stress in the fracture surface 1b of the sheared end face 1 can be reduced.

The present inventor has obtained the following new findings as a result of repeating a number of experiments and analyzes on the relationship between the shearing conditions for the steel material 5 and the properties of the sheared end face 1 generated by the shearing.

As shown in FIGS. 3A to 3C, a case where a part 11 of the steel material 5 is punched out by the first blade 21 and the other part 12 of the steel material 5 is punched out by the second blade 22 will be described. In this case, as shown in FIG. 3A, when the crack grows preferentially from the first blade 21 side, the tensile residual stress at the shear end face of the part 11 increases, while the tensile residual stress at the other part 12 increases. The tensile residual stress on the sheared end face of the is reduced. That is, while a part 11 is used as scrap 15, the other part 12 can be suitably used as a product (processed material 10). Further, as shown in FIG. 3B, when cracks grow equally from both the first blade 21 side and the second blade 22 side, they are equivalent to the shear end faces of both the partial 11 and the other portion 12. Tensile residual stress can occur. That is, the variation in the characteristics between the part 11 and the other part 12 can be suppressed. In this respect, it can be said that it is suitable when both the part 11 and the other part 12 are adopted as products. Further, as shown in FIG. 3C, when the crack grows preferentially from the second blade 22 side, the tensile residual stress at the shear end face of the other portion 12 increases, while the shear of a part 11 The tensile residual stress on the end face becomes smaller. That is, while the other part 12 is used as scrap 15, a part 11 can be suitably used as a product (processed material 10).

From the above, the following (1) to (3) can be said.
(1) The tensile residual stress generated in the fracture surface 1b of the shear end surface 1 changes depending on the growth direction and length of the cracks 1dx and 1dy forming the fracture surface 1b.
(2) In the fracture surface 1b, the longer the crack 1dx extending from the sagging 1a side (first blade side), the smaller the tensile residual stress of the fracture surface 1b of the work material 10, and the tensile residual stress of the fracture surface of the scrap 15. The stress increases.
(3) That is, in the fracture surface 1b of the processed material 10, the area ratio of the portion derived from the first crack 1dx extending from the sagging 1a side is the portion derived from the second crack 1dy extending from the burr 1c side. When it is larger than the area ratio, the area ratio of the part derived from the first crack 1dx extending from the sagging 1a side is smaller than the area ratio of the part derived from the second crack 1dy extending from the burr 1c side. Also, the tensile residual stress of the fracture surface 1b can be relatively reduced.

The present inventor has obtained the following new findings as a result of repeating a number of experiments and analyzes on controlling the growth direction and length of cracks 1dx and 1dy when the steel material 5 is sheared.
(4) In order to preferentially propagate cracks from the first blade 21 side when the steel material 5 is sheared, the friction coefficient of the first tip portion 21x of the first blade 21 is set to the second tip of the second blade 22. It is preferable to increase the coefficient of friction of the portion 22x relatively.

The shearing apparatus of the present disclosure and the method for manufacturing a processed material using the shearing apparatus have been completed based on the above findings.

2. 2. Shearing device As shown in FIG. 4, the shearing device 100 of the present disclosure includes a first blade 21 and a second blade 22, and the first blade 21 and the second blade 22 are relatively movable. The first blade 21 has a first bottom surface 21a, a first side surface 21b, and a first tip portion 21x, and a second blade 22 has a second bottom surface 22a, a second side surface 22b, and a second tip portion 22x. The friction coefficient of the first tip portion 21x is larger than the friction coefficient of the second tip portion 22x.

2.1 First blade The first blade 21 has a first bottom surface 21a, a first side surface 21b, and a first tip portion 21x. The first bottom surface 21a may have a surface that intersects the relative movement direction of the first blade 21, or may have a surface that is orthogonal to the movement direction. Further, the first side surface 21b may have a surface along the relative moving direction of the first blade 21, or may have a surface inclined with respect to the moving direction. Further, the first tip portion 21x refers to a portion near the line of intersection between the first bottom surface 21a and the first side surface 21b, and specifically, as shown in FIG. 5A, the first bottom surface 21a and the first surface. 1 Refers to a portion within a range of 2 mm from the line of intersection with the side surface 21b toward both the first bottom surface 21a side and the first side surface 21b side. When the tip of the first blade 21 is processed to have R or the tip is chamfered, a surface extended along the first bottom surface 21a and a surface extended along the first side surface 21b. The part included in the range of R + 2 mm from the line of intersection toward both the first bottom surface 21a side and the first side surface 21b side is regarded as the first tip portion 21x (see FIG. 5B). ). The first tip portion 21x can be specified in the same manner when the tip of the first blade 21 is chamfered.

In FIG. 5 (B), R is intentionally shown to be large for convenience of explanation, but the normal R is smaller than that shown in FIG. 5 (B). The R at the tip of the first blade 21 may be, for example, 0.02 mm or more.

The shape of the first bottom surface 21a can be determined according to the shape of the sheared end face 1 of the target processed material 10 (see FIG. 1). Regardless of the shape, if the coefficient of friction at the first tip portion 21x is relatively large, a desired effect can be exhibited. The first bottom surface 21a may have a flat surface or a curved surface, and the flat surface or the curved surface may face the first surface 10a when the steel material 5 (see FIG. 1) is sheared.

The shape of the first side surface 21b can be determined according to the shape of the sheared end face 1 of the target processed material 10. Regardless of the shape, if the coefficient of friction at the first tip portion 21x is relatively large, a desired effect can be exhibited. The first side surface 21b may be a flat surface, a curved surface, or a combination of a flat surface and a curved surface.

The first tip portion 21x may extend linearly or curvedly in the longitudinal direction of the first blade 21 (direction toward the back of the paper surface in FIG. 4), and may be a target processed material. It can be determined according to the shape of the sheared end face 1 of 10. When the steel material 5 is provided with a punch hole, the shape of the first tip portion 21x may be an annular shape along the edge of the punch hole.

In the standby state before the shearing operation, the first blade 21 may be arranged above the second blade 22. In this case, the first blade 21 may be a punch that punches a part of the steel material 5 placed on the second bottom surface 22a of the second blade 22 from top to bottom.

The first blade 21 is made of a material that is generally used as a blade provided in a shearing machine. For example, the first blade 21 may be made of SKD11. Further, as will be described later, the first blade 21 may have a first coating on its surface.

2.2 Second blade The second blade 22 has a second bottom surface 22a, a second side surface 22b, and a second tip portion 22x. The second bottom surface 22a may have a surface that intersects the relative movement direction of the second blade 22, or may have a surface that is orthogonal to the movement direction. Further, the second side surface 22b may have a surface along the relative moving direction of the second blade 22, or may have a surface inclined with respect to the moving direction. Further, the second tip portion 22x refers to a portion near the line of intersection between the second bottom surface 22a and the second side surface 22b, and is specified in the same manner as the first tip portion 21x. That is, it means a portion within a range of 2 mm from the line of intersection between the second bottom surface 22a and the second side surface 22b toward both the second bottom surface 22a side and the second side surface 22b side (FIG. 5A). When the tip of the second blade 22 is machined to have an R or the tip is chamfered, a surface extended along the second bottom surface 22a and a surface extended along the second side surface 22b. Assuming the line of intersection, the portion included within the range of R + 2 mm from the line of intersection toward both the second bottom surface 22a side and the second side surface 22b side is regarded as the second tip portion 22x. The second tip portion 22x can be specified in the same manner when the tip of the second blade 22 is chamfered. The R at the tip of the second blade 22 may be, for example, 0.05 mm or more. Further, the R of the tip of the second blade 22 may be larger than the R of the tip of the first blade 21.

The shape of the second bottom surface 22a can be determined according to the shape of the sheared end face 1 of the target processed material 10. Regardless of the shape, if the coefficient of friction at the second tip portion 22x is relatively small, the desired effect can be exhibited. The second bottom surface 22a may have a flat surface or a curved surface, and the flat surface or the curved surface may face the second surface 10b when the steel material 5 is sheared.

The shape of the second side surface 22b can be determined according to the shape of the sheared end face 1 of the target processed material 10. Regardless of the shape, if the coefficient of friction at the second tip portion 22x is relatively small, the desired effect can be exhibited. The second side surface 22b may be a flat surface, a curved surface, or a combination of a flat surface and a curved surface.

The second tip portion 22x may extend linearly or curvedly in the longitudinal direction of the second blade 22 (direction toward the back of the paper surface in FIG. 4), and may be a target processed material. It can be determined according to the shape of the sheared end face 1 of 10. When the steel material 5 is provided with a punch hole, the shape of the second tip portion 22x may be an annular shape along the edge of the punch hole.

In the standby state before the shearing operation, the second blade 22 may be arranged below the first blade 21. In this case, the second blade 22 may be a die on which the steel material 5 is placed.

The second blade 22 is made of a material that is generally used as a blade provided in a shearing machine. For example, the second blade 22 may be made of SKD11. The material of the second blade 22 may be the same as or different from the material of the first blade 21. Further, as will be described later, the second blade 22 may have a second coating on its surface.

2.3 Friction coefficient of the tip In the shearing apparatus 100, it is important that the friction coefficient of the first tip 21x is larger than the friction coefficient of the second tip 22x. This makes it easier to advance the first crack 1dx before the second crack 1dy. According to the knowledge of the present inventor, the larger the friction coefficient of the first tip portion 21x is larger than the friction coefficient of the second tip portion 22x, the easier it is to advance the first crack 1dx. For example, the coefficient of friction of the first tip portion 21x is 1.2 times or more, 1.3 times or more, 1.4 times or more, 1.5 times or more, 1.6 times or more the friction coefficient of the second tip portion. 1.7 times or more, 1.8 times or more, 1.9 times or more, 2.0 times or more, 2.1 times or more, 2.2 times or more, 2.3 times or more, 2.4 times or more or 2.5 times It may be the above. The upper limit of the friction coefficient ratio is not particularly limited. For example, the coefficient of friction of the first tip portion 21x may be 10.0 times or less, 8.0 times or less, or 6.0 times or less the friction coefficient of the second tip portion. There may be. The difference between the friction coefficient of the first tip portion 21x and the friction coefficient of the second tip portion 22x may be, for example, 0.05 or more, 0.10 or more, or 0.15 or more. It may be 0.20 or more. The specific values of the friction coefficient of the first tip portion 21x and the friction coefficient of the second tip portion 22x may be, for example, in the range of 0.01 or more and 3.0 or less.

The coefficient of friction of the first tip portion 21x and the second tip portion 22x is measured by a pin-on disk as follows. The pin material of the pin-on disc is SKD11 (equivalent to HRC58-60), and the pin diameter is φ0.71 cm (0.357 x 0.357 x π = 0.4 cm ² (0.9 MPa at 29.4 kN)). do. The load is 29.4 kN. The measurement condition is linear motion (pins are always moved so as to slide the new surface), and the pins on the tips 21x and 22x are scanned at a speed of 30 mm / sec. The scanning time is 7 seconds (moving distance 30 mm / sec × 7 seconds). The average value of the measured values excluding the first 1 second and the last 1 second is obtained, and this is used as the dynamic friction coefficient. The coefficient of dynamic friction is obtained at three different points of the tip portions 21x and 22x as described above, and the average value thereof is taken as the friction coefficient of the tip portions 21x and 22x. The friction coefficient may be measured by the above-mentioned measuring method at a portion (for example, the side surfaces 21b and 22b) that can be regarded as having the same level of friction coefficient as the tip portions 21x and 22x. Cases that cannot be regarded as having the same coefficient of friction as the tips 21x and 22x include, for example, when the type of coating has changed, when the coating thickness has changed by 1.5 times or more, or when the surface has changed. The case where the roughness changes by 1.5 times or more may be mentioned.

Various methods can be considered as a method for increasing the friction coefficient of the first tip portion 21x to be larger than the friction coefficient of the second tip portion 22x. For example, it is as follows.

2.3.1 Coating As shown in FIG. 6A, in the shearing apparatus 100, the second coating 32 may be applied to the second tip portion 22x. The second coating 32 may be applied to other parts in addition to the second tip portion 22x, and may be applied to, for example, a part or the whole of the second bottom surface 22a of the second blade 22. , May be applied to a part or the whole of the second side surface 22b. The second coating 32 may or may not have a function of protecting the surface of the second blade 22 and a function of relatively reducing the friction coefficient of the second tip portion 22x of the second blade 22. It does not have to be. As the second coating 32, a known coating may be adopted as the coating applied to the shearing tool. The second coating 32 may be an inorganic coating, and specifically, may be a coating containing at least one selected from TiC, TiN, TiCN, Cr, CrN, CrSiN and DLC.

As shown in FIG. 6B, in the shearing apparatus 100, the first coating 31 may be applied to the first tip portion 21x. The first coating 31 may be applied to other parts in addition to the first tip portion 21x, and may be applied to, for example, a part or the whole of the first bottom surface 21a of the first blade 21. , May be applied to a part or the whole of the first side surface 21b. The first coating 31 may or may not have a function of protecting the surface of the first blade 21 and a function of relatively increasing the friction coefficient of the first tip portion 21x of the first blade 21. It does not have to be. As the first coating 31, a known coating may be adopted as the coating applied to the shearing tool. The first coating 31 may be an inorganic coating, and specifically, it may be at least one selected from TiC, TiN, TiCN, Cr, CrN, CrSiN and DLC. The first coating 31 and the second coating 32 may be of the same type or different types.

As shown in FIG. 6C, in the shearing apparatus 100, the second tip portion 22x may be coated with the second coating 32, and the first tip portion 21x may be coated with the first coating 31. You may. In this case, the peeling life of the second coating 32 may be longer than the peeling life of the first coating 31. With the use of the shearing apparatus 100, a coating having a short peeling life is more likely to have a rough surface than a coating having a long peeling life. That is, a coating having a short peeling life tends to have a higher coefficient of friction than a coating having a long peeling life. As described above, on the side of the first blade 21, the coefficient of friction at the first tip portion 21x may be intentionally increased by intentionally adopting a coating having a short peeling life as the first coating 31. In other words, from the viewpoint of increasing the coefficient of friction, the peeling area of the first coating 31 on the first blade 21 may be large. For example, the peeled area of the first coating 31 is preferably 40% or more, 50% or more, or 60% or more of the total area (total of the coated portion and the peeled portion in the first tip portion 21x). On the other hand, on the second blade 22 side, it is preferable to use a coating having a long peeling life as the second coating 32, and in this case, the peeling area of the second coating 32 should be as small as possible. From the viewpoint of suppressing variation in the properties of the sheared end face, for example, the peeled area of the second coating 32 is preferably less than 10% of the total area (total of the coated portion and the peeled portion in the second tip portion 22x).

The "peeling life" of the coating provided at the tip is specified as follows. That is, the tip portion is photographed using an optical microscope to identify the area where the coating is peeled off. At this time, the peeling life is defined as the time when the coating having an area of 10% or more is peeled off in the region included in the tip portion.

As described above, the coefficient of friction of the first tip portion 21x can be made larger than the friction coefficient of the second tip portion 22x by adjusting the presence or absence of coating, the type of coating, the surface texture of the coating, and the like.

2.3.2 Surface roughness It is also possible to adjust the coefficient of friction of the tip by adjusting the surface roughness of the tip regardless of the presence or absence of the above coating. In this respect, in the shearing apparatus 100, the surface roughness of the first tip portion 21x may be larger than the surface roughness of the second tip portion 22x. The method for relatively increasing the surface roughness of the first tip portion 21x is not particularly limited, and is not particularly limited, and is mechanically polished, roughened or smoothed using a chemical agent, transferred by a roll with irregularities, and shot. Various methods such as peening can be mentioned.

The "surface roughness" of the first tip portion 21x and the second tip portion 22x means Rz measured as follows. That is, with a stylus probe, the stylus is moved from the bottom surface of the blade toward the side surface of the blade so as to include the tip portion, the shape of the blade is measured, and the Rz of the tip portion of the blade is calculated. In the measurement, a stylus made of diamond with a tip radius of 2 μm is used, the measuring force is 0.75 mN, and the measuring speed is 0.15 mm / s. Perform similar measurements at three locations and take the average.

2.4 Other configurations 2.4.1 Clearance As shown in FIG. 4, the shearing apparatus 100 may have a clearance C between the first blade 21 and the second blade 22. The clearance C can be appropriately determined depending on the material, shape, and the like of the work material (steel material 5). For example, when the steel material 5 has a plate shape, the clearance C may be 5% or more of the plate thickness or 25% or less of the plate thickness. The "clearance" referred to in the present application is in accordance with ISO 16630: 2009.

2.4.2 Shear angle As shown in FIG. 7, the shearing apparatus 100 may have a shear angle α between the first blade 21 and the second blade 22. The shear angle α can be appropriately determined depending on the material, shape, and the like of the work material (steel material 5). For example, the shear angle α may be 0 ° or more, or 10 ° or less. Further, according to a new finding of the present inventor, when the shear angle is 0 ° or more and 1 ° or less, the first crack 1dx is further advanced with respect to the steel material 5 before the second crack 1dy. easy.

2.4.3 Moving device The shearing device 100 may include general components of the shearing device 100 in addition to the first blade 21 and the second blade 22. As described above, in the shearing apparatus 100, the first blade 21 and the second blade 22 are configured to be relatively movable with respect to each other. For example, as shown by the black double-headed arrow in FIG. 4, the first blade 21 is configured to be movable up and down so that the first blade 21 can be moved closer to or further away from the second blade 22. You may. Alternatively, the second blade 22 may be configured to be movable, or both the first blade 21 and the second blade 22 may be configured to be movable. The relative movement of the first blade 21 and the second blade 22 may be performed by a known moving device (not shown) that can be incorporated in the shearing machine. Alternatively, the first blade 21 and the second blade 22 may be configured to be manually movable.

2.4.4 Holding member (holder)
The shearing apparatus 100 may include a holding member (holder) (not shown) that presses the steel material 5 against the first bottom surface 21a and the second bottom surface 22a. That is, the shearing apparatus 100 may have a pressing member facing the first blade 21, or may have a pressing member facing the second blade 22. The form of the pressing member is not particularly limited, and a general pressing member may be adopted.

3. 3. Manufacturing Method of Processed Material The technology disclosed in the present disclosure also has an aspect as a manufacturing method of processed material. The method for producing the processed material of the present disclosure is a method of producing the processed material 10 by using the shearing processing apparatus 100 of the present disclosure.
Arranging the steel material 5 between the first blade 21 and the second blade 22, where the steel material 5 has a first surface 10a and a second surface 10b on the opposite side of the first surface 10a, and is the first. The first bottom surface 21a of the blade 21 is in contact with the first surface 10a, the second bottom surface 22a of the second blade 22 is in contact with the second surface 10b, and
Shearing the steel material by relatively moving the first blade 21 and the second blade 22.
including. The configuration of the shearing apparatus 100 and the flow of shearing of the steel material 5 have already been described, and the description thereof will be omitted here.

The shape of the steel material 5 is not particularly limited as long as it can be sheared. The steel material 5 may be, for example, plate-shaped or rod-shaped. When the steel material 5 has a plate shape, the plate thickness may be, for example, 0.8 mm or more, 5.0 mm or less, or 3.0 mm or less. Further, when the steel material 5 has a rod shape, its cross-sectional shape is not particularly limited, and may be, for example, a circular shape or a polygonal shape, and the circle-equivalent diameter of the cross-sectional shape may be 5 mm or more, 100 mm. It may be as follows. Further, the steel material 5 may be formed into some shape by bending or the like.

As shown in FIGS. 1 and 2, the steel material 5 may include a first surface 10a and a second surface 10b opposite to the first surface 10a. The first surface 10a and the second surface 10b may be parallel to each other. The term "parallel" as used in the present application is not limited to perfect parallelism, but may be substantially parallel. That is, even if the first surface 10a and the second surface 10b are not completely parallel, they are regarded as parallel as long as they are within the margin of error allowed in industrial production. Specifically, when the angle formed by the first surface 10a and the second surface 10b is 0 ° ± 1 °, it is considered that the first surface 10a and the second surface 10b are parallel to each other.

The steel material 5 may have a surface treatment layer. Examples of the surface treatment layer include a plating layer and a coating film. Further, the steel material 5 may include a plurality of layers having different steel types. For example, it is also possible to use clad steel as the steel material 5.

The mechanical properties of the steel material 5 are not particularly limited and may be appropriately determined depending on the use of the steel material 5. However, problems such as a decrease in hydrogen embrittlement resistance due to tensile residual stress are particularly likely to occur in high-strength steel materials. In this respect, the tensile strength of the steel material 5 is preferably 980 MPa or more, more preferably 1180 MPa or more, and particularly preferably 1470 MPa or more. The upper limit of the tensile strength of the steel material 5 is not particularly limited, but may be, for example, 2500 MPa or less, 2200 MPa or less, or 2000 MPa or less. The "tensile strength" of the steel material referred to in the present application is in accordance with ISO 6892-1: 2009. Further, as the strength of the steel material 5 increases, the ratio of the fracture surface 1b to the shear end face 1 described later increases, that is, the portion where the tensile residual stress should be reduced increases, and the technique of the present disclosure has a further excellent effect. You can expect it.

The chemical composition and metallographic structure of the steel material 5 are not particularly limited, and may be appropriately determined depending on the use of the steel material 5. According to the technique of the present disclosure, it is possible to reduce the tensile residual stress in the fracture surface 1b regardless of the chemical composition and the metallographic structure of the steel material 5. As an example of the chemical composition, the steel material 5 has a mass% of C: 0.050 to 0.800%, Si: 0.01 to 3.00%, Mn: 0.01 to 10.00%, Al: 0. .001 to 0.500%, P: 0.100% or less, S: 0.050% or less, N: 0.010% or less, Cr: 0 to 3.000%, Mo: 0 to 1.000%, B: 0 to 0.0100%, Ti: 0 to 0.500%, Nb: 0 to 0.500%, V: 0 to 0.500%, Cu: 0 to 0.50%, Ni: 0 to 0 .50%, O: 0 to 0.020%, W: 0 to 0.100%, Ta: 0 to 0.10%, Co: 0 to 0.50%, Sn: 0 to 0.050%, Sb : 0 to 0.050%, As: 0 to 0.050%, Mg: 0 to 0.050%, Ca: 0 to 0.050%, Y: 0 to 0.050%, Zr: 0 to 0. It may have a chemical composition consisting of 050%, La: 0 to 0.050%, Ce: 0 to 0.050%, and the balance: Fe and impurities. Further, in the above chemical composition of the steel material 5, Cr, Mo, B, Ti, Nb, V, Cu, Ni, O, W, Ta, Co, Sn, Sb, As, Mg, which are elements arbitrarily added, The lower limit of the content of Ca, Y, Zr, La, and Ce may be 0.0001% or 0.001%.

4. Processed Material By shearing the steel material 5 using the shearing processing apparatus 100 of the present disclosure, a processed material 10 having a reduced tensile residual stress particularly in the fracture surface 1b among the sheared end faces 1 can be obtained. Hereinafter, an example of the processed material 10 having the sheared end face 1 will be described, but the form of the processed material 10 is not limited to the following. As shown in FIGS. 8 and 9, the sheared end surface 1 of the processed material 10 includes, for example, a sagging 1a, a fracture surface 1b, and a burr 1c. The fracture surface 1b includes a first portion 1bx and a second portion 1by. The first portion 1bx is formed by the first crack 1dx extending from the sagging 1a side to the burr 1c side, and the second portion 1by is formed by the second crack 1dy extending from the burr 1c side to the sagging 1a side. Will be done. The area ratio of the first portion 1bx in the fracture surface 1b is larger than the area ratio of the second portion 1by in the fracture surface 1b.

4.1 Shear end face As shown in FIGS. 8 and 9, the shear end face 1 includes a sagging 1a, a fracture surface 1b and a burr 1c. Further, the sheared end surface 1 may include a sheared surface 1e. Of the sheared end faces 1, the sagging 1a, the burrs 1c, and the sheared surface 1e can take any form depending on the form of the processed material 10. The sagging 1a, the burr 1c, and the sheared surface 1e may have the same form as the conventional one. The larger the ratio of the fracture surface 1b to the sheared end face 1 of the processed material 10, the larger the portion where the tensile residual stress should be reduced, and the more excellent effect of the technique of the present disclosure can be expected. In other words, it is preferable that the ratio of the fracture surface 1b to the end face of the workpiece 10 is large. For example, the area ratio of the fracture surface 1b is preferably 50% or more, based on the product (cut length x plate thickness) of the cut length of the processed material 10 and the cut thickness (plate thickness) (100 area%). It is preferably 55% or more, more preferably 60% or more, and particularly preferably 65% or more. The upper limit of the area ratio of the fracture surface 1b is not particularly limited, and may be 100%, 95% or less, or 90% or less.

The processed material 10 has one feature in the structure of the fracture surface 1b of the sheared end face 1. As shown in FIGS. 8 and 9, the fracture surface 1b includes a first portion 1bx and a second portion 1by. The first portion 1bx is formed by the first crack 1dx extending from the sagging 1a side to the burr 1c side, and the second portion 1by is formed by the second crack 1dy extending from the burr 1c side to the sagging 1a side. Will be done.

The growth direction of the first crack 1dx may be any direction from the sagging 1a side to the burr 1c side. When the processed material 10 has a plate shape, the growth direction of the first crack 1dx is a direction along the plate thickness direction of the processed material 10 (a direction orthogonal to the first surface 10a and the second surface 10b). It may be the direction inclined with respect to the plate thickness direction. Further, the growth direction of the second crack 1dy may be any direction from the burr 1c side to the sagging 1a side. When the processed material 10 has a plate shape, the growth direction of the second crack 1dy is a direction along the plate thickness direction of the processed material 10 (a direction orthogonal to the first surface 10a and the second surface 10b). It may be the direction inclined with respect to the plate thickness direction. For example, when a clearance C (see FIG. 4) is provided between the first blade 21 and the second blade 22 when the steel material 5 is sheared, the growth directions of the first crack 1dx and the second crack 1dy are It can be tilted with respect to the plate thickness direction, and the larger the clearance, the larger the tilt.

The first crack 1dx may be one that extends from the sagging 1a side to the burr 1c side and is combined with the second crack 1dy on the burr 1c side, and is not necessarily the first from the sagging 1a side to the burr 1c side. It is not necessary to travel in the shortest path toward 2 cracks 1 dy. For example, the first crack 1dx is in the direction toward the back of the paper surface in FIG. 2B (for example, in the plate width direction when the processed material 10 is plate-shaped) while extending from the sagging 1a side to the burr 1c side. You may progress towards. The same applies to the second crack 1dy.

In the sheared end face 1, the area ratio of the first portion 1bx in the fracture surface 1b is larger than the area ratio of the second portion 1by in the fracture surface 1b. In other words, on the sheared end face 1, the average length of the first crack 1dx extending from the sagging 1a side toward the burr 1c side is the average of the second crack 1dy extending from the burr 1c side toward the sagging 1a side. Longer than the length. As described above, when the area ratio of the portion of the fracture surface 1b derived from the crack 1dx extending from the sagging 1a side is larger than the area ratio of the portion derived from the crack 1dx extending from the burr 1c side, the fracture occurs. The tensile residual stress of the cross section 1b can be relatively reduced.

In order to specify the area ratio of each of the first portion 1bx and the second portion 1by and the length of each of the first crack 1dx and the second crack 1dy in the fracture surface 1b, the unevenness of the surface of the fracture surface 1b is determined. It shall not be considered. For example, as shown in FIG. 9, when the sheared end surface 1 is viewed from the front, the position that is the starting point of the first crack 1dx is P1, the position that is the starting point of the second crack 1dy is P2, and the first crack. When the position where the crack 1dx and the second crack 1dy meet is P3, the area ratio of the first portion 1bx in the fracture surface 1b when the distance between P1 and P3 is larger than the distance between P2 and P3. However, it can be determined that the area ratio of the second portion 1by in the fracture surface 1b is larger than the area ratio.

According to the findings of the present inventor, the larger the area ratio of the first portion 1bx in the fracture surface 1b, the smaller the tensile residual stress of the fracture surface 1b. For example, in the processed material 10, the area ratio of the first portion 1bx in the fracture surface 1b may be 1.2 times or more, or 1.5 times or more, the area ratio of the second portion 1by in the fracture surface 1b. It may be 1.7 times or more, 2.0 times or more, 2.2 times or more, or 2.5 times or more.

The burr 1c may have a size that cannot be visually confirmed. Regarding which of the first surface 10a and the second surface 10b of the processed material 10 is the surface on the sagging 1a side and which is the surface on the burr 1c side, the shape of the processed material 10 even if the burr 1c cannot be confirmed. Can be easily identified by observing.

In the sheared end surface 1, the properties of the sheared surface 1e and the fracture surface 1b are different. For example, the shear surface 1e and the fracture surface 1b have different roughness (glossiness). In this respect, the sheared surface 1e and the fracture surface 1b can be easily distinguished only by observing the appearance.

In the fracture surface 1b, the boundary between the first portion 1bx and the second portion 1by (the position where the first crack 1dx and the second crack 1dy meet) is formed by, for example, introducing a large amount of hydrogen into the shear end surface 1. It can be discriminated. As mentioned above, the stress generated during crack growth depends on the crack growth direction. That is, as shown in FIGS. 10A and 10B, it can be said that the residual stress suddenly changes at the position where the first crack 1dx and the second crack 1dy meet. Therefore, the direction of hydrogen embrittlement cracks caused by the intrusion of hydrogen also suddenly changes at the position where the first crack 1dx and the second crack 1dy meet. Considering this, the position where the direction of the hydrogen embrittlement crack suddenly changes can be regarded as the position where the first crack 1dx and the second crack 1dy meet.

4.2 Configuration other than the sheared end face The processed material 10 may have the sheared end face 1, and the configuration other than the sheared end face is not particularly limited. The shape of the processed material 10 corresponds to the shape of the steel material 5 described above. That is, the processed material 10 may be in the shape of a plate as described above or in the shape of a rod. Further, the processed material 10 may include a first surface 10a and a second surface 10b opposite to the first surface 10a as surfaces other than the sheared end surface 1, and the first surface 10a and the second surface 10a may be provided. The surface 10b may be connected via the sheared end surface 1. The first surface 10a and the second surface 10b may be parallel to each other. Further, the processed material 10 may have a surface treatment layer as described above. Further, the processed material 10 may include a plurality of layers having different steel types. The mechanical properties and chemical composition of the processed material 10 are also as described above.

5. Action / Effect As described above, according to the shearing apparatus 100 of the present disclosure, it is possible to manufacture the processed material 10 in which the tensile residual stress is reduced particularly in the fracture surface 1b among the sheared end faces 1. By reducing the tensile residual stress of the fracture surface 1b, for example, hydrogen embrittlement resistance or fatigue strength of the sheared end face 1 can be improved.

1. 1. Steel materials Steel materials to be processed include steel plate A1 (plate thickness 1.6 mm), steel plate A2 (plate thickness 0.8 mm) and steel plate A3 (plate thickness 4.0 mm) with a tensile strength of 1470 MPa class, and a tensile strength of 980 MPa. A grade steel plate B (plate thickness 1.6 mm) and a steel plate C having a tensile strength of 590 MPa (plate thickness 1.6 mm) were prepared.

2. 2. Shearing conditions for steel sheet By arranging the steel sheet between the punch and the die and moving the punch and the die relatively, a part of the steel sheet is sheared linearly with the punch to obtain a processed material with a sheared end face. rice field. On the sheared end face, sagging was formed on the punch side and burrs were formed on the die side. When shearing the steel plate, the shear angle between the punch and the die was set to 3 °, and the clearance was set to 10% of the plate thickness. Further, the R of the cutting edge (tip) of the punch and the R of the cutting edge (tip) of the die were both 0.1 mm. Before shearing the steel sheet, the punch or die was subjected to the treatment according to the following Example or Comparative Example to change the coefficient of friction at the tip of the punch or die.

2.1 Examination of coating Before shearing the steel sheet, at least one of the punch and the die was coated as in Examples 1 to 3 and Comparative Examples 1 to 3 below.

2.1.1 Example 1
Only the dies were DLC coated.

2.1.2 Example 2
Only the die was coated with CrSiN.

2.1.3 Example 3
Only the die was coated with TiN.

2.1.4 Comparative Example 1
Only the punches were DLC coated.

2.1.5 Comparative Example 2
Both the punch and the die were not coated and had the same coefficient of friction.

2.1.6 Shearing conditions of Comparative Example 3 TiN coating was applied to both the punch and the die, and the friction coefficient was the same.

2.2 Examination of Surface Roughness Before shearing the steel sheet, at least one of the punch and the die was subjected to the following polishing treatments as in Examples 4 to 6 and Comparative Examples 4 to 6.

2.2.1 Example 4
The surface of the die was polished using a grindstone having a grain size of # 230 (JIS R6001). The surface roughness Rz before polishing was 5 μm, and the surface roughness Rz after polishing was 1.6 μm. On the other hand, the punch was not particularly polished. The surface roughness Rz of the punch was 5 μm.

2.2.2 Example 5
The surface of the die was polished using a grindstone having a grain size of # 800 (JIS R6001). The surface roughness Rz before polishing was 5 μm, and the surface roughness Rz after polishing was 0.9 μm. On the other hand, the punch was not particularly polished. The surface roughness Rz of the punch was 5 μm.

2.2.3 Example 6
The surface of the die was polished using a grindstone having a grain size of # 1500 (JIS R6001). The surface roughness Rz before polishing was 5 μm, and the surface roughness Rz after polishing was 0.5 μm. On the other hand, the punch was not particularly polished. The surface roughness Rz of the punch was 5 μm.

2.2.4 Comparative Example 4
The surface of the punch was polished using a grindstone having a grain size of # 230 (JIS R6001). The surface roughness Rz before polishing was 5 μm, and the surface roughness Rz after polishing was 1.6 μm. On the other hand, the die was not particularly polished. The surface roughness Rz of the die was 5 μm.

2.2.5 Comparative Example 5
The surface of the punch was polished using a grindstone having a grain size of # 800 (JIS R6001). The surface roughness Rz before polishing was 5 μm, and the surface roughness Rz after polishing was 0.9 μm. On the other hand, the die was not particularly polished. The surface roughness Rz of the die was 5 μm.

2.2.6 Comparative Example 6
The surface of the punch was polished using a grindstone having a grain size of # 1500 (JIS R6001). The surface roughness Rz before polishing was 5 μm, and the surface roughness Rz after polishing was 0.5 μm. On the other hand, the die was not particularly polished. The surface roughness Rz of the die was 5 μm.

2.3 Examination of coating peeling life Before shearing of the steel sheet, at least one of the punch and the die was coated with the following Examples 7 and 8 and Comparative Examples 7 to 9.

2.3.1 Examples 7 and 8
The punch was TiN coated and the die was N + TiN coated.

2.3.2 Comparative Example 7
TiN coating was applied to the punch and die.

2.3.3 Comparative Example 8
N + TiCN coating was applied to the punch and die.

2.3.4 Comparative Example 9
The punch was N + TiN coated and the die was TiN coated.

3. 3. Evaluation conditions 3.1 Measurement of the coefficient of friction at the tip The coefficient of friction at the tip of the punch and die was measured. In Example 7 and Comparative Examples 7 to 9, the coefficient of friction of the tip of the punch and the die after punching the steel sheet 10,000 times was measured. At this time, in Example 7 and Comparative Examples 7 to 9, the area of about 90% of the TiN coating was peeled off. Further, in Example 8, the coefficient of friction of the tip of the punch and the die was measured after punching the steel plate 1000 times. At this time, in Example 8, the TiN coating was in a state where an area of about 30% was peeled off.

3.2 Residual stress on the sheared end face The residual stress on the sheared end face was measured for each of the processed materials according to Examples 1 to 8 and Comparative Examples 1 to 9 as follows. That is, at the center position in the plate thickness direction, the residual stress was measured by X-ray with a spot diameter of φ500 μm (three points different in the plate width direction). The residual stress was measured in three directions: the plate thickness direction, the plate width direction, and the 45 degree direction from the plate thickness direction, and the sin ² ψ method was used to calculate the residual stress. Assuming that the residual stress in the normal direction of the end face is zero, the maximum principal stress was calculated from the calculated residual stress in the three directions. The values of the maximum principal stress calculated at three points were averaged.

4. Evaluation Results The evaluation results are shown in Tables 1 to 3 below.

As shown in Tables 1 to 3, when the steel plate is sheared using a shearing device in which the friction coefficient of the tip of the punch is larger than the friction coefficient of the tip of the die, the processed material obtained after shearing is performed. It can be seen that the tensile residual stress of the fracture surface can be significantly reduced at the sheared end face. It is probable that the area ratio of the first portion derived from the first crack extending from the punch side could be increased in the fracture surface of the processed material. Such an effect is similarly recognized regardless of the strength of the steel sheet. When the area ratio of the fracture surface of the sheared end face of the steel plate B of Example 1 was measured, the product (cut length x plate thickness) of the cut length of the steel plate B and the cut thickness (plate thickness) was used as a reference (cut length × plate thickness). The area ratio of the fracture surface was 70%. Further, at the sheared end faces of the steel plates B of Examples 2 to 8 and the sheared end faces of the steel plates A1 to A3 of Examples 1 to 8, the area ratio of the fracture surface is the same as that of the steel plate B of Example 1, or is it the same? It was a larger area ratio than. As described above, when the ratio of the fracture surface to the sheared end face is large, it is considered that a higher effect can be obtained by reducing the tensile residual stress.

In the above embodiment, the embodiment in which the steel plate is used as the steel material is exemplified, but the technique of the present disclosure is not limited to this embodiment. As described above, the technique of the present disclosure is characterized in that the friction coefficient of the blade of the shearing machine is adjusted, and the same effect can be exhibited regardless of the shape of the steel material.

The processed material produced by the shearing processing apparatus of the present disclosure can be used as a constituent material of, for example, automobiles, home appliances, building structures, ships, bridges, construction machinery, various plants, pen stocks and the like.

1 Shear end face 1a Dripping 1b Fracture section 1b x 1st part 1by 2nd part 1c Bali 1dx 1st crack 1dy 2nd crack 1e Shear surface 5 Steel material 10 Work material 11 Part of steel material 12 Other part of steel material 15 Scrap 21 1 blade 21a 1st bottom surface 21b 1st side surface 21x 1st tip portion 22 2nd blade 22a 2nd bottom surface 22b 2nd side surface 22x 2nd tip portion 100 Shearing device

Claims (10)

A shearing machine equipped with a first blade and a second blade.
The first blade and the second blade are configured to be relatively movable.
The first blade has a first bottom surface, a first side surface, and a first tip portion.
The second blade has a second bottom surface, a second side surface, and a second tip portion.
The coefficient of friction of the first tip is larger than the coefficient of friction of the second tip.
Shearing equipment. The coefficient of friction of the first tip is 1.5 times or more the coefficient of friction of the second tip.
The shearing apparatus according to claim 1. The coefficient of friction of the first tip is 2.0 times or more the coefficient of friction of the second tip.
The shearing apparatus according to claim 1. A second coating is applied to the second tip portion.
The shearing apparatus according to any one of claims 1 to 3. A second coating is applied to the second tip portion.
The first coating is applied to the first tip portion.
The peeling life of the second coating is longer than the peeling life of the first coating.
The shearing apparatus according to any one of claims 1 to 4. The surface roughness of the first tip portion is larger than the surface roughness of the second tip portion.
The shearing apparatus according to any one of claims 1 to 5. A method for manufacturing a processed material using the shearing apparatus according to any one of claims 1 to 6.
Arranging a steel material between the first blade and the second blade, where the steel material has a first surface and a second surface opposite to the first surface, and the first blade The first bottom surface is in contact with the first surface, the second bottom surface of the second blade is in contact with the second surface, and
Shearing the steel material by relatively moving the first blade and the second blade.
A method for manufacturing a processed material, including. The steel material is plate-shaped,
The manufacturing method according to claim 7. The tensile strength of the steel material is 980 MPa or more.
The manufacturing method according to claim 7 or 8. The tensile strength of the steel material is 1470 MPa or more.
The manufacturing method according to claim 9.

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