JP7144802B2 - How to introduce equivalent strain - Google Patents

Description

The present invention relates to a method of introducing equivalent strain.

Conventionally, the HPS (High-Pressure Sliding) method, the HPT (High-Pressure Torsion) method, and the like are known as methods for imparting new characteristics by applying considerable strain to a metal body (see, for example, Patent Document 1). ).

For example, in the HPS method, a metal body is pressurized and sandwiched between upper and lower molds, and a considerable strain is applied to the metal body by relatively sliding the upper and lower molds in a direction substantially perpendicular to the pressing direction. method.

Also, in the HPT method, the upper and lower molds are provided with a recessed housing to accommodate the metal body, and while the metal body is pressed and held between the upper and lower molds, the upper and lower molds are rotated relative to each other around the pressing direction. This is a method of imparting an equivalent strain to a metal body by moving it.

According to these HPS and HPT methods, a large amount of strain is introduced into the metal body to form high-density dislocations, thereby refining the structure to nano- or sub-micron size. can be improved, the crystal orientation can be controlled, and the like.

Therefore, it is expected that various properties will be improved, such as improving the workability of the metal body and imparting new functional properties to the metal body.

JP-A-2009-61499

By the way, the above-mentioned HPS method and HPT method involve sliding or rotating while compressing from above and below, but the clamping area and pressure depend solely on the scale of the device that introduces the equivalent strain. There are many, and the scale of the equipment is naturally limited due to installation locations, costs, and the like.

However, for example, it is desired to introduce considerable strain to a metal body that has a large area that exceeds the area of the opposing surfaces of the upper and lower molds installed in the existing equipment, or a metal body that has a thickness. a demand exists.

The present invention has been made in view of such circumstances, and while suppressing an increase in the size of the device as much as possible, the metal strain having a larger volume than the equivalent strain introduction portion formed in one introduction step To provide a method for introducing equivalent strain, which enables introduction of equivalent strain over a wider range to a body.

In order to solve the conventional problems described above, in the method for introducing equivalent strain according to the present invention, (1) a pair of clamping bodies with a metal body interposed therebetween moves in parallel with each other, so that the first clamping pressure 1. A method for introducing an equivalent strain, comprising an introduction step of forming an equivalent strain introducing portion between one side of a metal body following a body and the other side of a metal body following a second clamping body, comprising: moving the pressing position on the metal body by the pressing body to the target position where the introduction step is performed, with respect to the metal body having a volume larger than the equivalent strain introducing portion formed in the introduction step of Accordingly, the introduction step is continuously or intermittently repeated over a plurality of locations along the curved virtual line set on the metal body to form the equivalent strain introducing portion in one direction along the curved virtual line. I decided to
(2) One side of the metal body that follows the first pressure body and the second pressure body follow the relative parallel movement of the pair of pressure bodies with the metal bodies interposed therebetween. A method for introducing an equivalent strain, comprising an introducing step of forming an equivalent strain introducing portion between the metal body and the other side of the metal body, the equivalent strain introducing portion having a larger volume than the equivalent strain introducing portion formed in one introducing step. Moving the pinching position on the metal body by the pinching body against the metal body, along a plurality of straight or curved imaginary lines set on the metal body according to the target position where the introduction step is performed Repeating the introduction step continuously or intermittently over a plurality of locations on each virtual line while changing the virtual line to form the equivalent strain introduction part in one direction along the straight or curved virtual line. did.

In addition, the method of introducing equivalent strain according to the present invention is also characterized by the following points.
(3) The parallel motion is a linear motion or a rotary motion with the axis as the direction of pressing .
(4) The parallel movement is rotational movement with the axis being the direction of pressing, and the plurality of imaginary lines are formed concentrically.

In addition, in the method for introducing equivalent strain according to the present invention, ( 5 ) one of the metal bodies following the first clamping body accompanies the relative parallel movement of the pair of clamping bodies with the metal bodies interposed therebetween. an introduction step of forming an equivalent strain introduction portion between the side and the other side of the metal body following the second clamping body, and having a larger volume than the equivalent strain introduction portion formed in one introduction step A method for introducing an equivalent strain in which the introduction step is performed at a plurality of predetermined portions of the metal body by moving the pinching position on the metal body by the pinching body with respect to the metal body having , the metal body has a thickness greater than the thickness in the pinching direction of the equivalent strain introducing portion formed in one introduction step, the parallel motion is a linear motion, and the first pinching When the metal body is accommodated in the accommodation space formed between the body and the second clamping body and the equivalent strain introducing portion is formed in layers over a plurality of locations in the thickness direction, the clamping position is moved. may be performed by changing the boundary position between the first and second pinching bodies in the pinching direction.

In addition, in the method for introducing equivalent strain according to the present embodiment, (6) a first gripping body that is gripped while a predetermined part of a rod-shaped metal body having a constant cross-sectional outer shape in the longitudinal direction is inserted and The boundary between the first and second grips accompanies the relative movement in the direction orthogonal to the extension direction of the metal body with the second grip that is gripped with the one end of the remaining part inserted . A method for introducing an equivalent strain, comprising an introduction step of forming an equivalent strain introduction portion in a metal body existing in a region, wherein the metal body has a larger volume than the equivalent strain introduction portion formed in one introduction step On the other hand, the relative position in the extension direction of the metal body with respect to the boundary area is moved while being inserted into the first gripping body and the second gripping body, and the metal body is moved to a predetermined portion at a plurality of locations. The introduction step may be performed over a period of time.

Further, in the surface property changing method according to the present embodiment, the surface property of the metal material surface to which the equivalent strain is introduced by the method of introducing the equivalent strain according to any one of ( 7 ) (1) to ( 6 ) is changed. In the method of , in making the surface texture of the metal material surface the desired surface texture by pressing it against a mold body having a mold surface with a desired surface texture, miniaturization derived from the method of introducing the equivalent strain The surface property changing step is carried out under elongation-increasing conditions with a temperature, pressure contact force, and strain rate at which the elongation of the metal material exceeds 200% according to the degree of refinement of the crystal grains.

In the method of introducing equivalent strain according to the present invention, one side of the metal body following the first clamping body and the second clamping body follow the relative parallel movement of the pair of clamping bodies with the metal bodies interposed therebetween. A method for introducing an equivalent strain, comprising an introduction step of forming an equivalent strain introduction portion between the other side of a metal body following a clamping body, wherein the equivalent strain introduction portion formed in one introduction step is Since the introduction step is performed over a plurality of predetermined portions of the metal body by moving the clamping position on the metal body by the clamping body with respect to the metal body having a large volume, A method of introducing equivalent strain that enables introduction of equivalent strain over a wider range to a metal body having a volume larger than the equivalent strain introducing portion formed in one introduction step without increasing the size of the device. can be provided.

It is an explanatory view showing an example of an equivalent strain introduction device. It is an explanatory view showing a cross section of the main part of the equivalent strain introduction device. It is explanatory drawing which showed the formation process of the equivalent strain introduction part. FIG. 10 is a schematic diagram showing the shapes of a mold and an intervening metal body in the second HPS technique; It is explanatory drawing which showed the formation process of the equivalent strain introduction part. FIG. 10 is a schematic diagram showing the shapes of a mold and an intervening metal body in the third HPS technique; It is explanatory drawing which showed the formation process of the equivalent strain introduction part. FIG. 4 is a schematic diagram showing the shape of an anvil and an intervening metal body in the first HPT method. FIG. 4 is an explanatory diagram showing a process of forming an equivalent strain introducing portion according to the first HPS method according to the present embodiment; FIG. 4 is an explanatory diagram showing a process of forming an equivalent strain introducing portion according to the first HPS method according to the present embodiment; FIG. 4 is an explanatory diagram showing a process of forming an equivalent strain introducing portion according to the first HPS method according to the present embodiment; FIG. 4 is an explanatory diagram showing a process of forming an equivalent strain introducing portion according to the first HPS method according to the present embodiment; FIG. 4 is an explanatory diagram showing a process of forming an equivalent strain introducing portion according to the first HPS method according to the present embodiment; FIG. 4 is an explanatory diagram showing a process of forming an equivalent strain introduction portion according to the first HPT method according to the present embodiment; FIG. 4 is an explanatory diagram showing a process of forming an equivalent strain introduction portion according to the first HPT method according to the present embodiment; FIG. 4 is an explanatory diagram showing virtual lines set on a metal body; FIG. 4 is an explanatory diagram showing the configuration of an anvil used in the equivalent strain introduction method according to the first HPT method according to the present embodiment; FIG. 4 is an explanatory diagram showing a process of forming an equivalent strain introduction portion according to the first HPT method according to the present embodiment; FIG. 10 is an explanatory diagram showing the appearance of a metal body used for forming an equivalent strain introducing portion according to the second HPS method according to the present embodiment; FIG. 10 is an explanatory diagram showing the configuration of a mold used in the equivalent strain introduction method according to the second HPS technique according to the present embodiment; FIG. 10 is an explanatory diagram showing a process of forming an equivalent strain introducing portion according to the second HPS technique according to the present embodiment; FIG. 11 is an explanatory diagram showing a process of forming an equivalent strain introducing portion according to another example according to the second HPS method according to the present embodiment; FIG. 10 is an explanatory diagram showing a process of forming an equivalent strain introducing portion according to the third HPS method according to the present embodiment; FIG. 10 is an explanatory diagram showing a working process of a metal body according to Experimental Example 1; FIG. 10 is an explanatory diagram showing a working process of a metal body according to Experimental Example 1; FIG. 5 is an explanatory diagram showing the results of Experimental Example 1; FIG. 8 is an explanatory diagram showing an experimental method according to Experimental Example 2; FIG. 10 is an explanatory diagram showing the results of Experimental Example 2; FIG. 10 is an explanatory diagram showing the results of Experimental Example 2; FIG. 10 is an explanatory diagram showing the results of Experimental Example 2; FIG. 10 is an explanatory diagram showing the results of Experimental Example 3; FIG. 10 is an explanatory diagram showing the results of Experimental Example 3; FIG. 10 is an explanatory diagram showing the results of Experimental Example 3; FIG. 10 is an explanatory diagram showing the results of Experimental Example 3; FIG. 10 is an explanatory diagram showing the results of Experimental Example 3; FIG. 4 is an explanatory diagram showing an example of a surface property changing method according to the present embodiment;

The present invention relates to a pair of clamping bodies with metal bodies interposed therebetween, accompanied by relative parallel movement, one side of the metal body following the first clamping body and the metal body following the second clamping body. A method for introducing an equivalent strain comprising an introduction step of forming an equivalent strain introduction part between the body and the other side, wherein the equivalent strain introduction part is formed in a single introduction step without increasing the size of the device. To provide a method for introducing equivalent strain, which enables introduction of equivalent strain over a wider range to a metal body having a larger volume.

In addition, according to the present invention, the boundary between the first and second grippers is moved along with the relative movement of the first gripper that grips a portion of the metal body and the second gripper that grips the remaining portion of the metal body. An equivalent strain introduction method comprising an introduction step of forming an equivalent strain introduction portion in a metal body existing in a region, wherein the equivalent strain introduction portion is formed in a single introduction step without increasing the size of the apparatus. The present invention also provides a method of introducing equivalent strain that enables introduction of equivalent strain over a wider range to a metal body having a large volume.

Here, the material of the metal body is not particularly limited, and any metal material can be adopted. Among them, metal materials such as aluminum alloys, magnesium alloys, titanium alloys, and nickel-based alloys can be processed, and superplasticity can be expressed.

In particular, heat-resistant alloy materials such as INCONEL718 (INCONEL is a registered trademark) have excellent high-temperature properties such as heat resistance, corrosion resistance, and oxidation resistance, and are widely used in the nuclear industry, industrial turbines, aircraft jet engines, and turbocharger parts. Although it is a material with high utility value in various fields, it is also a material that is difficult to process, so it is difficult to process compared to other metal materials, making it difficult to improve productivity and reduce costs. However, in this regard, according to the equivalent strain introduction method according to the present embodiment, while suppressing the enlargement of the equivalent strain imparting device, the equivalent strain imparting device formed in one step of introducing the equivalent strain Since it is possible to introduce equivalent strain to a metal body that has a larger volume than the strain introduction part, not only can it improve the workability of difficult-to-work materials, but it is also excellent in mass productivity, improving productivity and reducing costs. This is extremely advantageous in that it is possible to achieve reduction.

In addition, in the method for introducing equivalent strain according to the present embodiment, the introduction step of forming the equivalent strain introducing portion in the metal body is performed by relatively parallel movement of a pair of clamping bodies with the metal body interposed therebetween, This is achieved by the relative opposing movement of the first gripping body that grips a portion of the metal body and the second gripping body that grips the remaining portion.

The relative parallel movement and countermovement of the clamping body are not particularly limited, but for example, it is possible to adopt a method that conforms to the methods of introducing various equivalent strains that have been studied by the present inventors. can.

Here, in order to provide an understanding of the present invention, first, the relative parallel movement of the clamping body and the relative opposing movement of the gripping body will be described while showing some representative examples.

One method belonging to the HPS method is the method shown in FIGS. 1 and 2 (hereinafter referred to as the first HSP method for convenience). FIG. 1 is an explanatory diagram showing a schematic configuration of an equivalent strain introducing device for forming an equivalent strain introducing portion in a metal body by the first HSP method, and FIG. be.

As shown in FIG. 1, the equivalent strain introduction device 10 includes a first mold 11 corresponding to a first clamping body, a second mold 12 corresponding to a second clamping body, an upper anvil 13 and a lower anvil. 14, a bed 15, a slide 16, a first hydraulic device 17 as a drive device, and a second hydraulic device 18 as a slide device. Note that FIG. 1 omits additional components such as a control unit for controlling the driving of these hydraulic devices and a body frame to facilitate understanding of the structure and operation.

The first hydraulic device 17 has a cylinder portion 17a fixed to the body frame, and a piston portion 17b configured to be telescopic with respect to the cylinder portion 17a. The piston portion 17b is configured to be able to advance and retreat in the pressurizing direction D3 with respect to the cylinder portion 17a, and the slide 16 is fixed to the tip of the piston portion 17b.

A fixed concave portion 16a for fixing a mold is formed in the lower surface of the slide 16, and the upper anvil 13 is fixed to the fixed concave portion 16a. In the example shown in FIG. 1 , the base of the upper anvil 13 is embedded in the fixing recess 16 a and fixed, and the upper anvil 13 protrudes from the slide 16 toward the lower anvil 14 . A first mold 11 is fixed in a nested manner in the grooves on the lower surface of the upper anvil 13 .

The lower surface of the slide 16 faces the upper surface of the bed 15 to which the lower anvil 14 is fixed.

A fixed concave portion 15a for fixing a mold is formed on the upper surface of the bed 15, and the lower anvil 14 is fixed to the fixed concave portion 15a. In the example shown in FIG. 1, the base of the lower anvil 14 is fixed in the fixed recess 15a in an embedded state, and the mold portion of the lower anvil 14 protrudes from the bed 15 toward the upper anvil 13. . The second mold 12 is nested in the grooves on the upper surface of the lower anvil 14 and is slidable along the length direction D1 (the direction in which the grooves extend). That is, the sliding movement of the second die 12 is guided by the grooves of the lower anvil 14 .

The second mold 12 is driven by the second hydraulic device 18 so as to slide relative to the first mold 11 in the length direction D1.

The second hydraulic device 18 has a cylinder portion 18a and a piston portion 18b that can extend and retract from the cylinder portion 18a. There is. The piston portion 18b expands and contracts in the length direction D1. When the piston portion 18b of the second hydraulic device 18 is extended and contracted in the length direction D1 to drive the push rod 18c, the push rod 18c contacts the second mold 12 and pushes the second mold 12 against the first mold 11. slide to move.

In addition, the first mold 11 has a high-friction surface facing the second mold 12 . Similarly, the second mold 12 also has a high-friction surface facing the first mold 11 .

According to the equivalent strain introduction device 10 configured as described above, when the piston portion 17b of the first hydraulic device 17 is advanced in the pressurizing direction D3 to drive the slide 16, the upper anvil 13 is shown in FIG. is driven in a direction approaching the lower anvil 14, the first mold 11 approaches the second mold 12, and the plate-like metal body M interposed as a processing object is pressed.

Next, while maintaining this clamping state, the piston portion 18b of the second hydraulic device 18 advances in the pressurizing direction D1 to drive the second mold 12 (moves forward in FIG. 2).

Then, by this operation, as shown in FIG. 3A, the upper surface side Mu (one side) of the metal body M following the first mold 11 (first clamping body) and the second mold 12 ( Equivalent strain is introduced into the metal body M between the lower surface side Md (the other side) of the metal body M following the second clamping body), and is shown by diagonal grid hatching in FIG. Thus, the equivalent strain introduction portion S is formed inside the thickness. For this operation, a third hydraulic device may be arranged on the opposite side of the second hydraulic device 18 to accelerate the introduction of the equivalent strain by reciprocating machining.

As another example of the method belonging to the HPS method, there is a method shown in FIG. 4 (hereinafter referred to as the second HPS method for convenience). FIG. 4 is a schematic diagram showing the shapes of the mold and the intervening metal body in the equivalent strain introduction device according to the second HPS method.

As shown in FIG. 4, also in the second HPS method, a metal body is placed between a first mold 21 corresponding to the first clamping body and a second mold 22 corresponding to the second clamping body. The equivalent strain introducing portion is formed while pressing with the metal M interposed therebetween. A recess 21a is formed, and a second recess 22a having substantially the same shape as the lower half of the metal body M is formed on the upper surface of the second die 22 facing the first die 21. is housed in the housing space 23 formed by the first recess 21a and the second recess 22a when the first mold 21 and the second mold 22 are brought close to each other.

That is, as in the above-described first HPS method, the first hydraulic device that advances and retreats in the pressurizing direction, the second hydraulic device that advances and retreats in the length or width direction, etc. are used, and as shown in FIG. The metal mold 21 and the second mold 22 are brought close to each other by the first hydraulic device or the like, and the metal body M interposed in the housing space 23 is pressed, and as shown in FIG. 5B, the pressed state is maintained. The first mold 21 or the second mold 22 (the second mold 22 in FIG. 5(b)) is moved in parallel by the second hydraulic device or the like.

Then, by this operation, the upper half (one side) of the metal body M following the first mold 21 (first clamping body) and the second mold 22 (second clamping body) are followed. The inside of the metal body M located at the boundary surface between the first mold 21 and the second mold 22, in other words, between the first mold 21 and the lower half (other side) of the metal body M Equivalent strain is induced in the portion of the metal body M crossed by the imaginary boundary plane including the dividing plane with the second mold 22, and as shown by hatching, the equivalent strain is induced in the longitudinal direction of the metal body M. Part S is formed.

Such a second HPS method is extremely useful in forming the equivalent strain introducing portion S in a rod-shaped metal body, for example.

In particular, as shown in FIG. 5(b), the first mold 21 and the second mold 22 are subjected to relative movement (here, a pair of opposed bottom surfaces of the metal body M in the direction of the bottom surface). Regulation for suppressing the sliding of the metal body M in the first recess 21a and the second recess 22a against the drag force from the metal body M accompanying the relative movement of the mold 21 and the second mold 22) Walls 24a to 24d are provided to efficiently apply a shearing force to the metal body M, thereby enabling formation of the equivalent strain introducing portion S in which equivalent strain is effectively introduced.

In addition, when the second mold 22 is moved in the direction of the arrow U1 indicated by the outline solid line relative to the first mold 21, the restriction wall 24a and the restriction wall 24d resist the reaction force from the metal body M. The control wall 24b and the control wall 24c function as control walls that resist the drag force from the metal body M when moved in the direction of the arrow U2 indicated by the outline dashed line. is.

That is, the rod-shaped (here, columnar) metal body M shown in FIG. 5(a) is deformed into the state shown in FIG. After forming, it may be returned to a state of substantially the same shape as the original shape shown in FIG. 5(a) by relatively moving in the direction of arrow U2. Of course, if there is no need to return the shape to its original state, the number of control walls may be reduced as necessary.

Also, the inner surfaces of the first recess 21a and the second recess 22a are preferably rough surfaces. In particular, when the metal body M is a high-strength, difficult-to-work material such as a nickel-based superalloy such as INCONEL718, various metal materials, such as superplasticity exhibiting elongation of 400% or more, or 100% or more and less than 400% It is useful for refining crystal grains to the extent that a property that exhibits elongation (hereinafter referred to as quasi-superplasticity) can be expressed.

The degree of roughness of the inner surfaces of the first concave portion 21a and the second concave portion 22a can be appropriately set depending on the metal body M to be processed. 45 μm is desirable. With such a configuration, the equivalent strain can be effectively introduced to the metal body M.

The clamping pressure of the metal body M by the first and second molds 21 and 22 can be appropriately set depending on the material of the metal body M, but is generally 1.0 GPa to 10 GPa, preferably 1.5 GPa to 4 GPa. be able to. This clamping pressure is considerably reduced compared to the fact that a minimum of about 4 GPa is normally required when refining grains to the extent that the above-mentioned superplasticity or quasi-superplasticity can be expressed. ing. This is one of the effects of the rough surfaces formed on the regulation walls 24a to 24d and the inner surfaces of the recesses 21a and 22a.

Thus, it can be said that the second HPS method is a very useful method in forming the equivalent strain introduction portion S in the metal body M, particularly in the rod-like metal body M.

Further, as another example of the method belonging to the HPS method, there is a method shown in FIG. 6 (hereinafter referred to as the third HPS method for convenience). FIG. 6 is a schematic diagram showing the shapes of a mold and intervening metal bodies in an equivalent strain introduction device according to the third HPS method.

As shown in FIG. 6, in the third HPS method, a first mold 25 corresponding to the first grip and a second mold 26 and a third mold 27 corresponding to the second grip are provided. and the first to third molds 25
, 26 and 27 are provided with recesses and holes that form a housing space 28 having substantially the same shape as the outer shape of the metal body M when integrally connected.

Specifically, the first mold 25 has a first hole 25a formed so as to be able to grip a part of the middle portion of the metal body M, and the second mold 26 has a first hole portion 25a formed to hold the remaining part of the metal body M. A second hole 26a formed to be grippable and a third hole 27a formed to be able to grip the other end of the remaining portion of the metal body M are provided in the third mold 27, respectively.

Then, by connecting the metal molds 25 to 27 together, a corresponding strain introducing portion is formed by interposing and compressing the metal body M in the housing space 28 formed by the respective hole portions 25a to 27a.

That is, as in the above-described first HPS method, using the first hydraulic device that advances and retreats in the pressurizing direction and the second hydraulic device that advances and retreats in the direction crossing the metal body M, as shown in FIG. The second mold 26 and the third mold 27 are brought close to each other through the first mold 25 by the first hydraulic device or the like, and the metal body M interposed in the housing space 28 is pressed, as shown in FIG. 7(b). 7(b), the first mold 21 is moved relative to the second mold 26 and the third mold 27 by the second hydraulic device or the like while maintaining the clamping state. move in the opposite direction.

Then, by this operation, the middle portion (part) of the metal body M following the first mold 25 (first gripped body) and the metal body M following the second metal mold 26 (second gripped body) are formed. and the middle portion (part) of the metal body M following the first mold 25 (first gripping body) and the third mold 27 (second Equivalent strain is introduced into the inside of the metal body M existing in the boundary area with the right part (remaining other end side) of the metal body M following the gripping body), and the equivalent strain introduction part S shown by hatching is formed. be done.

Next, the methods belonging to the HPT method will continue to be illustrated. As one of the HPT methods, there is a method shown in FIG. 8 (hereinafter referred to as the first HPT method for convenience). FIG. 8 is a schematic diagram showing the shapes of the mold and the intervening metal bodies in the equivalent strain introduction device according to the first HPT method.

As shown in FIG. 8(a), the equivalent strain introduction device according to the first HPT method has a substantially circular cross section corresponding to the first pressing body and the second pressing body arranged to face each other. two anvils (upper anvil 31, lower anvil 32). Forming surfaces 33 and 34 of the two anvils 31 and 32 are formed with circular recesses 33a and 34a having substantially the same diameter as the diameter of the disk-shaped metal body M. The circular recess 33a , 34a. A pressing means (not shown) is connected to at least one of the two anvils 31 and 32 via a support base, and a disc-shaped pressing means is squeezed between the circular concave portions 33a and 34a of the two anvils 31 and 32. A pressure of several GPa can be applied to the metal body M in the thickness direction thereof. A rotating means (not shown) is connected to at least one of the two anvils 31 and 32 via a support base. Rotating one anvil with respect to the other provides relative parallel motion.

Using the equivalent strain introduction device having such a configuration, while pressing the disk-shaped metal body M between the circular recesses 33a and 34a of the two anvils 31 and 32 with a pressure of several GPa, for example, about 6 GPa, One anvil is rotated relative to the other anvil.

As a result of this operation, as shown in FIG. 8B, the upper surface side Mu (one side) of the metal body M following the upper anvil 31 (first clamping member) and the lower anvil 32 (second clamping member) are formed. An equivalent strain is introduced into the metal body M between the lower surface side Md (the other side) of the metal body M following the pressure body), and as shown by hatching in FIG. A strain introducing portion S is formed.

So far, the first to third HPS methods and the first HPT method have been described as examples. In order to perform the strain introduction step, it is necessary to perform processing with a larger clamping body, and it is necessary to increase the size of the equivalent strain introduction device itself.

Further, in the second and third HPS methods, the equivalent strain introducing portion S is only formed in a part of the metal body M, and it is difficult to form the equivalent strain introducing portion S as a whole.

That is, it has been difficult to introduce an equivalent strain over a wider range to a metal body having a large volume such as a thickness and a spread larger than the equivalent strain introducing portion formed in a single introduction step.

Therefore, in the equivalent strain introduction method according to the present embodiment, as one of its characteristic configurations, a metal body having a larger volume than the equivalent strain introduction portion formed in one introduction step is subjected to pinching. By moving the clamping position on the metal body by the body, the introduction step is performed to a plurality of predetermined portions of the metal body.

In addition, as the first gripping body that grips a part of the metal body and the second gripping body that grips the remaining part of the metal body move relative to each other, the metal existing in the boundary area between the first and second gripping bodies A method for introducing an equivalent strain, comprising an introduction step of forming an equivalent strain introduction part in a body, wherein a metal body having a larger volume than the equivalent strain introduction part formed in one introduction step is applied to the boundary region It is also characterized by moving the relative position of the metal body and performing the introduction step over a plurality of predetermined parts of the metal body.

In particular, according to the former, according to the above-mentioned first and second HPS methods and the first HPT method, it can be a method of introducing equivalent strain that is more versatile and expanded, and the metal body can be wider It becomes possible to form the equivalent strain introduction part over a range.

Also, in the latter, in accordance with the above-mentioned third HPS method, similarly, it is possible to introduce a method of introducing equivalent strain that is more versatile and expanded, and introduces equivalent strain over a wider range of the metal body. It becomes possible to form a part.

These methods of introducing equivalent strain according to the present embodiment, which are more extended than conventional methods, can also be interpreted as more specific examples described below.

FIG. 9 is an explanatory diagram showing an example in which the equivalent strain introduction method according to the present embodiment is applied by an introduction process according to the first HPS method. In the application examples described below, as shown in the legend in FIG. S) is indicated by slanted grid shading.

As shown in FIG. 9( a ), the metal body M can be formed with an equivalent strain introducing portion S in the thickness direction from the front surface to the back surface by performing the introduction step, but the pressing area by the pressing body The metal body has an area larger than that of the equivalent strain introduction portion S formed in one introduction step and a volume larger than that of the equivalent strain introduction portion S formed in one introduction step.

Therefore, first, an introduction step is performed at an arbitrary position P1 to form an equivalent strain introduction portion S, then the metal body M is moved, and an arbitrary position P2 shown in FIG. Perform the introduction process as Alternatively, the introduction step may be performed by further moving the metal body M and setting an arbitrary position P3 shown in FIG. 9(c) as the clamping position.

As described above, according to the method of introducing equivalent strain according to the present embodiment, the size of the metal body M that can be processed has been limited to the size range that can be clamped by the clamping body. Since the introduction step is performed at a plurality of locations on the metal body M by moving the clamping position on the metal body M, the device can be formed in a single introduction process without increasing the size of the apparatus. Equivalent strain can be introduced over a wider range to a metal body having a volume larger than that of the strain introduction portion.

Further, the method of introducing equivalent strain shown in FIG. When forging is to be performed on a plurality of parts separated from each other on the metal body M, the target part is given a degree of freedom in the two-dimensional direction to cause crystal refinement and superplasticity is applied to perform the forging process. can be done.

Also, the multiple target sites subjected to the introduction step do not have to be spaced apart. As shown in FIG. 10(a), first, an introduction step is performed at an arbitrary position P1 to form an equivalent strain introduction portion S, and then, as shown in FIG. The introduction step may be performed, and part (or all) of the equivalent strain introduction portion S and the target region overlap like the relationship between the position P2 and the position P3 shown in FIG. 10(c). The introduction step may be performed as follows.

With such a configuration, the equivalent strain introduction portion S continuous with the previously formed equivalent strain introduction portion S can be formed, and the region on the metal body M where the equivalent strain introduction portion S is desired to be formed is once Even if it is larger than the equivalent strain introduction portion S formed in the introduction step of 1, it is possible to form the equivalent strain introduction portion S without a gap.

In the examples shown in FIGS. 9 and 10, when forming the equivalent strain introducing portions S at a plurality of locations, the pressing position on the metal body M can be changed by moving the metal body M while the pressing position is fixed. I did, but it's not limited to this. Although it is generally thought that an equivalent strain introduction device having a clamping body is more difficult to move than a metal body M to be processed, a moving device may be provided in some cases to move the metal to be processed. The clamping position of the clamping body may be changed while the body M is fixed, or both may be moved.

That is, the movement of the pinching position on the metal body M is sufficient if the positional relationship between the pinching body and the metal body M can be relatively changed. In addition, in the drawings referred to in the following description, regarding the positional relationship between the metal body M and the clamping body, only the relative positional relationship is shown.

In carrying out the method of introducing the equivalent strain according to the present embodiment, a virtual line may be set on the metal body M so as to connect the target sites where the introduction step is performed. Although this imaginary line does not prevent the line from being actually drawn on the metal body M, it should be understood as a line connecting the target sites where the introduction step is performed, regardless of the presence or absence of the drawn line.

Then, the introduction step may be continuously or intermittently repeated along the virtual line to form the equivalent strain introduction portion S in one dimension, that is, in one direction along the virtual line.

To explain with reference to the drawings, in FIG. 11(a), a straight imaginary line L indicated by a one-dot chain line is set on the metal body M. As shown in FIG. As shown in a-1, first, the introduction step is performed with the position P1, which is one end of the imaginary line L, as the pinching position, and then the pinching position P2 shown in a-2 is set along the imaginary line L. .

By performing the introduction step along the imaginary line L in this manner, it is possible to steadily form the equivalent strain introduction portion S for a plurality of target portions existing on the metal body M.

Also, in a-2, the position P1 and the position P2 are close to each other, but in a-3, they are overlapping positions as shown by position P3, or continuous positions such as positions P1 to P3. Instead, equivalent strain introducing portions S may be formed at discrete positions, ie, intermittent positions, as indicated by position P4 in a-4.

Also, the imaginary line does not necessarily have to be straight, and may be curved according to the target position where the introduction step is performed.

That is, in FIG. 11(b), a curved imaginary line L indicated by a dashed dotted line is set on the metal body M. The introduction step is performed as the pinching position, and then the pinching position P2 shown in b-2 is a position close to the position P1 along the imaginary line L. Since the imaginary line L is a curve, the position P2 is a position Although it is adjacent to the long side of P1, the short sides are irregular.

By performing the introduction step along the curved imaginary line L in this manner, the equivalent strain introduction portion S can be formed with a higher degree of freedom for a plurality of target portions existing on the metal body M. becomes possible.

In addition, as in a-3 and a-4, the introduction step is intermittently performed at a position where b-3 is superimposed as shown by position P3, or at a separated position as shown by position P4 in b-4. Equivalent strain introducing portion S may be formed.

Also, the number of virtual lines on the metal body M is not necessarily one, and a plurality of lines may be set.

When the curved virtual line shown in FIG. 11B is set, compared to the case where the straight virtual line is set, the equivalent strain introduction portion S can be formed while being displaced in the left and right direction of the paper, so it is more flexible. Although it can be said that this is a method of introducing a high degree of equivalent strain, it is difficult to form the equivalent strain introducing portion S beyond the left-right width of the clamping body even when a curved imaginary line is set.

On the other hand, if a plurality of virtual lines are set on the metal body M, it becomes possible to process a wider range of the metal body M with a two-dimensional spread.

To explain with reference to the drawings, two straight imaginary lines L1 and L2 indicated by one-dot chain lines are set on the metal body M in FIG. As shown in FIG. 12(a), first, a position P1, which is one end of the imaginary line L1, is set as the pinching position, and the introduction step is performed. As P2, an introduction step is performed by a clamping body.

When such processing is repeated along the virtual line L1 until the other end indicated by the position P3 in FIG. 12(c) is reached, then, as shown in FIG. The introduction step is repeated again along the virtual line L2 from the position P4.

By performing the introduction step along a plurality of imaginary lines set on the metal body M in this manner, a wider range of the metal body M can be processed with a two-dimensional spread.

In addition, when a plurality of virtual lines are set on the metal body M, it is not necessary to move to the introduction process on another virtual line after finishing the processing of the introduction process on a predetermined virtual line, and considerable strain is applied while changing the virtual line. An introduction part S may be formed.

Specifically, as shown in FIG. 13(a), first, a position P1, which is one end of the virtual line L1, is pressed against the metal body M on which two straight virtual lines L1 and L2 are set. After performing the introduction step as the position, the introduction step is performed with the target site changed to a position P2 on the virtual line L2 as shown in FIG. The introduction step is performed at a different position P3 on the line L1.

By repeating such a zigzag motion, it is possible to process a wider range of the metal body M with a two-dimensional spread, as shown in FIG. 13(d). In the examples shown in FIGS. 12 and 13, the introduction step is performed while the previously formed equivalent strain introduction portion S and the pinching position are adjacent to each other, but as described above, they are overlapped or overlapped. It goes without saying that they can be separated from each other.

As described above, the equivalent strain introduction method according to the present embodiment can be interpreted as the above-described example in light of the introduction process according to the first HPS method in which the relative parallel movement of the clamping body is linear. , it is also possible to apply the introduction process according to the above-mentioned first HPT method.

FIG. 14 is an explanatory diagram showing an example in which the equivalent strain introduction method according to the present embodiment is applied by an introduction process according to the first HPT method.

Even in the case of performing the introduction step according to the first HPT method, the size of the metal body M that can be processed so far is reduced to the pinching body, as in the introduction step according to the first HPS method. However, by moving the clamping position on the metal body M and performing the introduction step to a predetermined portion of the metal body M over a plurality of locations, the apparatus can be enlarged. It is possible to introduce equivalent strain over a wider range to a metal body having a larger volume than the equivalent strain introduction portion formed in one introduction step without becoming distorted.

That is, as shown in FIG. 14(a), the pinching position P1 may be a position separated from the position P2 or the position P3, which is the equivalent strain introduction portion S previously formed, or the position shown in FIG. 14(b) As shown in FIG. 14C, the pinching position P1 and the positions P2 and P3 where the equivalent strain introduction portion S is previously formed are adjacent or overlapped, or the pinching position The positions P2 to P4 where P1 and the equivalent strain introduction portion S are formed are adjacent or superimposed, or the introduction step is performed multiple times along the curved imaginary line L as shown in FIG. As shown in (e), the introduction step may be performed along a plurality of virtual lines L1 and L2.

Further, as shown in FIG. 15(a), first, a position P1, which is one end of the virtual line L1, is introduced as a clamping position to the metal body M on which three straight virtual lines L1 to L3 are set. After performing the steps, the target site is moved to a position P2 on the virtual line L2 as shown in FIG. 15(b), and the introduction step is performed. The introduction step may be performed at a different position P3, and the introduction step may be performed again at a different position P4 on the virtual line L1 as shown in FIG. 15(d). By repeating such a zigzag motion, it is possible to process a wider range of the metal body M with a two-dimensional spread, as shown in FIG. 15(e).

Further, when performing the introduction step according to the first HPT method, concentric imaginary lines may be set on the metal body M as shown in FIG. In this case, as in the example in which a plurality of virtual lines are set and the introduction process is performed, the equivalent strain introducing portion S can be formed in the metal body M by performing the introduction process a plurality of times with respect to one virtual line. Although it is possible to form the corresponding strain introducing portion S, here, another example of forming the equivalent strain introduction portion S will be described.

When forming the equivalent strain introduction portion S along the virtual lines L1 to L3 set concentrically, in this embodiment, the first to third three anvils shown in FIG. 17 are used to perform the introduction step.

The first anvil 40 shown in FIG. 17(a) functions as a pinching body when performing the introduction process along the imaginary line L1. Circular molding surfaces 43 and 44 having diameters larger than the imaginary line L1 and having diameters along the imaginary line L1 are formed.

Further, the second anvil 45 shown in FIG. 17(b) functions as a clamping body when performing the introduction process along the imaginary line L2, and the upper anvil 46 and the lower anvil 47 are arranged more than the imaginary line L2. A ring-shaped molding surface 48 in which portions corresponding to the circular regions of the molding surfaces 43 and 44 of the first anvil 40 are removed by the recesses 50 and 51 from the large diameter circular region along the imaginary line L2.
, 49 are formed.

Further, the third anvil 52 shown in FIG. 17(c) functions as a clamping body when performing the introduction process along the imaginary line L3. A portion corresponding to the circular area of the molding surfaces 43 and 44 of the first anvil 40 and the ring-shaped area of the molding surfaces 48 and 49 of the second anvil 45 from the circular area having the largest diameter along the imaginary line L3. Ring-shaped molding surfaces 57, 58 are formed which are excluded by recesses 55, 56. FIG.

The upper and lower anvils 31, 32 used in the first HPT method described with reference to FIG. , the equivalent strain is introduced while constraining the metal body M. However, the first to third anvils 40, 45, 52 are characteristic in that they do not have a constraining wall on the forming surface. In other words, by making the forming surface flat without a restraining wall, it is possible to perform sequential processing. The upper and lower anvils 31, 32 are different. In addition, the term "flat" as used herein does not necessarily mean a flat surface, and may be a parallel curved surface or irregular surface between the upper and lower anvils of the first to third anvils 40, 45, 52.

In addition, each pair of molds and the like has a high friction surface, a low friction surface formed in proximity along the edge of the high friction surface, , and while the high-friction surface grips the metal body M firmly, the low-friction surface may slip on purpose to suppress crushing and elongation. Further, as a further feature, the method of introducing equivalent strain according to the present embodiment may be implemented while providing the following points.
・The conveying distance should be less than the width of the high-friction surface in the conveying direction.
・The high-friction surface of one of the paired molds and the other high-friction surface of the mold should be substantially flat surfaces parallel to each other.
- The low-friction surface of one mold or the like and the low-friction surface of the other mold or the like that are paired should have a gradual separation structure in which the further away from the high-friction surface, the farther away they are from each other.
・Make a hill shape with a flat top surface as the high-friction surface.

These configurations can be applied not only to the first HPT method but also to other methods. Moreover, as a specific example of these, for example, Japanese Patent Application No. 2016-026443 can be cited.

Then, as shown in the left diagram of FIG. 18(a), between the upper and lower anvils 41 and 42 of the first anvil 40 attached to the equivalent strain introduction device, the central axis of the virtual line L1 and the rotation axis of the first anvil 40 By pressing the metal body M so that it is coaxial with each other, and performing a relative rotation operation as shown in the middle diagram, the equivalent strain introducing portion S1 along the virtual line L1 as shown in the right diagram to form

Next, when moving the clamping position on the metal body M from the virtual line L1 to the virtual line L2, the clamping body of the equivalent strain introduction device is set to the second anvil 45, and the left figure of FIG. As shown in FIG. 2, a metal body M is interposed between the upper and lower anvils 46 and 47 so that the center axis of the imaginary line L2 and the rotation axis of the second anvil 45 are coaxial with each other. By performing a relative rotational motion, an equivalent strain introducing portion S2 is formed along the virtual line L2 as shown in the right figure.

Then, when moving the pinching position on the metal body M from the virtual line L2 to the virtual line L3, the pinching body of the equivalent strain introduction device is set to the third anvil 52, and the left figure of FIG. As shown, between the upper and lower anvils 53 and 54, a metal body M is interposed and pressed so that the central axis of the imaginary line L3 and the rotation axis of the third anvil 52 are coaxial. Equivalent strain introduction portion S3 is formed along virtual line L3 as shown in the right figure by performing a typical rotation operation.

By performing the introduction step along the virtual lines L1 to L3 set concentrically on the metal body M in this way, the equivalent strain introduction portions S1 to S3 are formed as shown in the right diagram of FIG. 18(c). The equivalent strain introducing portion S can be machined over a wider range of the metal body M with a two-dimensional spread. The narrowing position when forming the equivalent strain introducing portion S2 for the previously formed equivalent strain introducing portion S1 and the pinching position when forming the equivalent strain introducing portion S3 for the equivalent strain introducing portion S2 are shown in FIG. , the positions are adjacent to each other, but it goes without saying that they may be superimposed or separated from each other as described above.

Next, an example in which the equivalent strain introduction method according to the present embodiment is applied by an introduction process according to the second HPS technique will be described.

In the second HPS method described above, as described with reference to FIG. The equivalent strain introducing portion S can be formed only at one location, and the equivalent strain introducing portion S is only formed in a part of the metal body M, and it is difficult to form the equivalent strain introducing portion S as a whole. there were.

In this respect, the equivalent strain introduction portion S can be formed in the entire metal body M by performing the equivalent strain introduction method according to the present embodiment through the introduction step according to the second HPS method.

FIG. 19 is an explanatory diagram showing a metal body M used as an example of the object to be processed in this embodiment. This metal body M has substantially the same shape as the metal object to be processed in the second HPS method. belongs to.

In this embodiment, as shown in FIG. 19, the metal body M is conceptually divided in the thickness direction, although it is actually an integral shape. Here, the metal body M is conceptually divided into layered first portions 60a to sixth portions 60f each parallel to the thickness direction. In addition, the number of divisions is not particularly limited, and here, in order to form the equivalent strain introducing portion S for the entire thickness direction of the metal body M, it is formed when performing the introducing step at the boundary portion of each portion Six divisions are illustrated as the number of divisions in which the range of the equivalent strain introduction portion S is adjacent to or overlaps with each other. For example, the number of divisions and the division positions corresponding to the necessary boundaries may be set.

Moreover, FIG. 20 is an exploded perspective view showing the structure of the mold used in this embodiment. A split mold 61 shown in FIG. 20 is used here as an example of the mold used for the introduction step. The split mold 61 has a first mold 62 to a sixth mold 67 .

The first mold 62 has a slightly thick rectangular plate-shaped mold substrate 62a, and an accommodation recess 62b having substantially the same shape as the first portion 60a of the metal body M is formed on the lower surface of the mold substrate 62a.

Adjustment rod insertion holes 62c penetrating the upper and lower sides of the mold substrate 62a are formed in four locations near the corners of the mold substrate 62a. is inserted.

A stopper 69 is attached to each boundary position upper adjusting rod 68, so that the insertion depth of each boundary position upper adjusting rod 68 can be fixed to the upper surface of the mold substrate 62a at an arbitrary position.

The sixth mold 67 is configured to have substantially the same shape as the first mold 62 by upside down. A recess 67b is formed. In addition, adjusting rod insertion holes 67c are formed through the upper and lower sides of the mold base plate 67a at four locations near the corners, and stoppers are provided in the adjustment rod insertion holes 67c so that they can be engaged with the lower surface of the mold base plate 67a. A boundary position lower adjustment rod 70 with 69 is inserted therethrough.

The second mold 63 to the fifth mold 66 are molds arranged between the first mold 62 and the sixth mold 67, and have mold substrates 62a to 67a in the shape of rectangular plates, Insertion holes 62c to 67c for inserting the boundary position upper adjusting rod 68 or the boundary position lower adjusting rod 70 are formed in each corner.

Further, the second to fifth molds 63 to 66 are provided with receiving holes 63b to 66b corresponding to the shape of each portion of the metal body M. As shown in FIG. The housing hole portion 63b of the second mold 63 has substantially the same shape as the second portion 60b of the metal body M, and the housing hole portion 64b of the third mold 64 has the third portion 60c and the fourth mold 65. The accommodating hole portion 65b has substantially the same shape as the fourth portion 60d, and the accommodating hole portion 66b of the fifth mold 66 has substantially the same shape as the fifth portion 60e. That is, the housing holes 63b to 66b of the second mold 63 to the fifth mold 66 are the housing spaces for housing the metal body M together with the housing recesses 62b and 67b of the first mold 62 and the sixth mold 67. configure.

The split mold 61 having such a configuration adjusts the depth position of each boundary position upper adjustment rod 68 and each boundary position lower adjustment rod 70 in a state in which the first mold 62 to the sixth mold 67 are stacked. By doing so, the boundary position can be changed in the pinching direction.

For example, while each boundary position upper adjustment rod 68 is inserted to the middle position of the insertion hole 63c of the second mold 63, each boundary position lower adjustment rod 70 is inserted to the middle position of the insertion hole 64c of the third mold 64. For example, the first mold 62 and the second mold 63 function as upper molds as one clamping body, and the third mold 64 to sixth mold 67 function as lower molds as the other clamping body. will function as For convenience in describing this embodiment, for example, when the upper mold is the first mold 62 and the lower mold is composed of the second mold 63 to the sixth mold 67, the distance between both molds The boundary is called a first boundary, and for example, when the upper mold is composed of the first mold 62 to the fourth mold 65 and the lower mold is composed of the fifth mold 66 and the sixth mold 67 The boundary between molds is referred to as the fourth boundary.

Then, using this split mold 61, in implementing the method of introducing the equivalent strain according to the present embodiment by the introduction process according to the second HPS method, first, as shown in the left diagram of FIG. Then, the metal body M is accommodated in the accommodation space in the split mold 61, and each boundary position upper adjustment rod 68 is inserted to the middle position of the adjustment rod insertion hole 62c of the first mold 62, while each boundary position With the lower adjusting rod 70 inserted to the middle position of the insertion hole 63c of the second mold 63, an upper mold and a lower mold bordering on the first boundary are constructed.

Next, similar to the first HPS method described above, the upper and lower molds are moved to the first hydraulic pressure level using the first hydraulic system that advances and retreats in the pressurizing direction and the second hydraulic system that advances and retreats in the length or width direction. The metal bodies M brought close to each other and interposed in the housing space are clamped by a device or the like, and as shown in the middle diagram of FIG. Move the mold in parallel.

Then, by this operation, the first portion 60a (one side) of the metal body M following the upper die (first clamping body) and the metal body following the lower die (second clamping body) are formed. Between the second part 60b to the sixth part 60f (other side) of M, that is, equivalent strain is introduced inside the metal body M located at the first boundary, and the middle and right sides of FIG. An equivalent strain introducing portion S1 is formed as indicated by dark shading in the drawing.

Here, the relative positions of the upper and lower molds are temporarily returned to the state shown in the left diagram of FIG. 21(a), and then, as shown in the left diagram of FIG. is inserted to the middle position of the insertion hole 63c of the second mold 63, while each boundary position lower adjusting rod 70 is inserted to the middle position of the insertion hole 64c of the third mold 64. It constitutes an upper mold and a lower mold. That is, the boundary position between the upper mold and the lower mold is changed in the pressing direction.

Then, the upper mold and the lower mold are brought close to each other by the first hydraulic device or the like, and the metal body M interposed in the housing space is compressed, and the compressed state is maintained as shown in the middle diagram of FIG. 21(b). When the upper mold or the lower mold is moved in parallel by the second hydraulic device or the like, the first part 60a and the second part 60b (one part) of the metal body M following the upper mold (first clamping body). side) and the third part 60c to sixth part 60f (other side) of the metal body M following the lower mold (second clamping body), that is, the metal body M located at the second boundary An equivalent strain is introduced into the inside of the , forming an equivalent strain introducing portion S2 as indicated by dark hatching in the middle and right diagrams of FIG. 21(b).

Similarly, after this, the introduction step is performed while changing the boundary position in the third boundary and the fourth boundary in the pinching direction to form equivalent strain introduction portions S3 and S4, respectively.

In this way, as shown in the left diagram of FIG. 21(c), an upper mold and a lower mold are configured with the fifth boundary as a boundary, and the mold is introduced as shown in the middle diagram of FIG. 21(c). By carrying out the steps to form the equivalent strain introducing portion S5 and returning the relative position of the mold, the equivalent strain introducing portion S can be formed in the entire metal body M. In addition, it is possible to introduce equivalent strain over a wider range to a metal body having a thickness (larger volume) larger than the equivalent strain introducing portion formed in one introduction step.

Next, another example of the introduction process according to the second HPS method will be described. In this other example, similar to the example of the introduction process according to the second HPS method described above, the introduction process is performed on the rod-shaped metal body M over a plurality of locations, and the equivalent is formed in one introduction process. The equivalent strain introducing portion S is formed on the metal body M having a volume larger than that of the strain introducing portion. The configuration is different in that they are performed with different phases.

Specifically, first, using the first mold 21 and the second mold 22 shown in FIG. The molds are relatively moved in a predetermined direction along the dividing plane of 22, and as shown in FIG. A corresponding strain introducing portion S1 is formed in the portion of the metal body M crossed by the two dies 21 and 22 so that the metal body M returns to its original shape.

Next, the mold is opened once, and the metal body M is rotated by a predetermined angle around the axis as shown in FIG. 22(b). Both molds are closed with different phase changes.

When the second introduction step is performed in this state, a new equivalent strain introduction portion S2 is formed as shown in FIG. 22(c).

By repeating this operation a predetermined number of times (FIG. 22(d)) and a fourth time (FIG. 22(e)), the metal body M becomes approximately approx. An equivalent strain introducing portion can be formed over the entirety. In addition, according to this other example as well, it is possible to introduce equivalent strain over a wider range to a metal body having a greater thickness (larger volume) than the equivalent strain introducing portion formed in a single introduction step. It can be carried out.

Next, with regard to the method of introducing the equivalent strain according to the present embodiment, an example in which the method is applied by the introduction process according to the third HPS method will be described.

In the third HPS method described above, as described with reference to FIGS. 6 and 7, for example, when the cylindrical metal body M is processed, a part of the metal body M is provided with an equivalent strain introducing portion It was difficult to form the equivalent strain introducing portion S with a spread in the extension direction (longitudinal direction) of the metal body M.

In this regard, by implementing the method of introducing the equivalent strain according to the present embodiment through the introduction step according to the third HPS method, the equivalent strain introducing portion can be continuously or intermittently spread over a wide range in the longitudinal direction of the metal body M. It becomes possible to form S.

FIG. 23 is an explanatory diagram showing a metal body M used as an example of the object to be processed in this embodiment. It is of shape.

Further, as in the third HPS method described above, also in this embodiment, the first mold 71 corresponding to the first gripping body, the second mold 72 corresponding to the second gripping body, and the third As shown in FIG. 23, the first to third molds 71, 72, 73 have the outer shape of the metal body M passing through these molds when integrally connected. Holes are provided to form the housing space 28 having substantially the same shape as the shape.

Specifically, the first mold 71 has a first hole 71a formed so as to be able to grip a predetermined part of the metal body M, and the second mold 72 has a remaining one end side of the metal body M. A second hole portion 72a is formed so as to be able to hold the second hole portion 72a, and the third mold 73 is provided with a third hole portion 73a formed so that the other end side of the remaining portion of the metal body M can be gripped.

Then, by connecting the metal molds 71 to 73, the metal body M is inserted into the housing space 74 formed by the holes 71a to 73a, and pressed to form the equivalent strain introducing portion.

That is, as in the above-described third HPS method, the first hydraulic device that advances and retreats in the pressurizing direction, the second hydraulic device that advances and retreats in the direction across the metal body M, the second mold 72 and the third mold 73 A second mold 72 holding the metal body M as shown in FIG. The third mold 73 is brought close to the first mold 71 by the first hydraulic device or the like, and the metal body M interposed in the housing space 74 is pressed, and as shown in FIG. 23(b), the pressed state is maintained. In this state, the first mold 71 is moved relatively to face the second mold 72 and the third mold 73 by the second hydraulic device or the like.

Then, due to this operation, a predetermined part of the metal body M following the first mold 71 (first gripped body) and the left side of the metal body M following the second metal mold 72 (second gripped body) part (remaining one end side), and a predetermined part of the metal body M following the first mold 71 (first gripped body) and the third mold 73 (second gripped body) Equivalent strain is introduced into the interior of the metal body M existing in the boundary area with the right portion (remaining other end side) of the following metal body M, and equivalent strain introduction portions S1a and S1b are formed as indicated by hatching. .

Here, the relative positions of the first mold 71, the second mold 72 and the third mold 73 are temporarily returned to the state shown in FIG. As shown in c), the metal body M and the boundary area are moved in a predetermined direction (here, the left direction of the paper surface indicated by the black arrow) in the direction in which the metal body M is pressed by the second mold 72 and the third mold 73. is moved by a predetermined distance.

Then, again, the second mold 72 and the third mold 73 holding the metal body M are brought close to the first mold 71 to clamp the metal body M, and as shown in FIG. is maintained, the first mold 71 is moved relative to the second mold 72 and the third mold 73 by the second hydraulic device or the like to form the equivalent strain introducing portions S2a and S2b.

In this way, the above-described operation and introduction steps are repeated for the metal body M having a volume larger than the equivalent strain introducing portion formed in one introduction step, and the relative position of the metal body M with respect to the boundary area is moved. By performing the introduction step to a predetermined portion of the metal body M over a plurality of locations, the equivalent strain introduction portion S can be formed continuously or intermittently over a wide range in the longitudinal direction of the metal body M.

Next, the method of introducing equivalent strain according to this embodiment will be described more specifically with reference to experimental examples.
[Experimental example 1]
In this experimental example, an example in which the equivalent strain introduction method according to the present embodiment is applied by an introduction process according to the first HPS technique is shown.

As shown in FIG. 24, a plate material made of INCONEL718 having a length of 190 mm, a width of 100 mm, and a thickness of 1 mm is used as a metal body M, and the formation region of the equivalent strain introduction part S is separated or partially separated under room temperature conditions. The introduction step was performed 10 times while overlapping the . The clamping pressure by the clamping body in the introduction process is 4 GPa, the parallel movement speed is 1 mm/sec, the parallel movement distance is 5 mm for the 1st and 2nd passes, and 10 mm for the 3rd to 10th passes, and processed at room temperature. did. The results are shown in FIG. The dashed lines in the 1st and 2nd passes in FIG. 24 indicate virtual lines along which the introduction step is performed, and each pass was performed in a zigzag pattern while changing the virtual lines.

As can be seen from FIG. 24, according to the method of introducing equivalent strain according to the present embodiment, a plate material having a volume larger than the equivalent strain introducing portion formed in one introduction step is pressed by a mold. It was shown that by moving the position and performing the introduction step over a plurality of predetermined portions of the plate material, it is possible to form the equivalent strain introduction part over a wide range of the plate material.

Next, a plate material made of INCONEL718 was used as the metal body M, and the elongation rate of the plate material after processing when the parallel movement distance was changed was examined. Specifically, as shown in FIG. 25( a ), the plate material was subjected to the introduction process seven times. In FIG. 25( a ), the intersecting shaded portions overlap between the 2nd and 3rd passes, the 4th and 5th passes, and the 6th and 7th passes, and indicate the portions where the introduction process was performed. , and thick dashed lines indicate imaginary lines.

In each pass of the introduction process, the clamping pressure by the clamping body was 4 GPa, the parallel movement speed was 1 mm/sec, and the room temperature was used. The thickness was 10 mm for the 5th and 5th passes, and 15 mm for the 6th and 7th passes. FIG. 25(b) shows the state of the actually processed plate material, and FIG. 25(c) shows the state of the plate material after the test sample is taken from the processed plate material.

The test samples consisted of a non-overlapping area (hereinafter referred to as the right area) in the 2nd, 4th, and 6th passes with parallel motion distances of 5 mm, 10 mm, and 15 mm, respectively, and , the non-overlapping area of the 7th pass (hereinafter referred to as the left area), the 2nd and 3rd passes, the 4th and 5th passes, and the 6th pass with the parallel motion distances set to 5 mm, 10 mm, and 15 mm, respectively. The sample was taken from the area where the introduction step was performed by overlapping between the first pass and the seventh pass (hereinafter referred to as the overlapped area).

FIG. 26 shows the results of measuring the elongation of the obtained test samples. As can be seen from FIG. 26, under the same test conditions, the unprocessed plate has an elongation of about 35%, but the elongation rate exceeds that of the unprocessed plate in both the left and right regions that are not overlapped. , suggesting that the equivalent strain is introduced into the plate with a two-dimensional spread.

Regarding the relationship with the parallel displacement distance, the elongation rate was about 60% at 5 mm, but it was about 240% at 10 mm, and furthermore, at 15 mm, the expression of superplasticity well over 400% was observed. rice field. No significant difference was observed between the left and right regions.

In addition, in the overlapping region, even when the translation distance is 10 mm, the elongation rate is almost the same as when the translation distance is 15 mm, confirming that superplasticity is manifested. The lower diagram of FIG. 26 shows the state after the test of the test sample collected from the site where the introduction process was superimposed between the 6th and 7th passes.

From these, by implementing the equivalent strain introduction method according to the present embodiment, for a metal body having a volume larger than the equivalent strain introduction part formed in one introduction step of the equivalent strain imparting device, It was shown that equivalent strain can be introduced without increasing the size of the equivalent strain introduction device.

In addition, it is considered to be extremely advantageous in that the workability of difficult-to-work materials can be improved, and mass productivity and cost reduction can be achieved.

[Experimental example 2]
In this experimental example, the equivalent strain introduction method according to the present embodiment is applied by the introduction process according to the first HPT method. An example of how to introduce an equivalent strain when

A plate material made of INCONEL718 having a diameter of 80 mm and a thickness of 1 mm was used as a metal body M, and under room temperature conditions, for example, as shown in FIGS. The introduction step was performed using two anvils. Details of the experimental conditions are shown in FIG.

The anvils consisted of a first anvil with a circular molding surface of 35 mm in diameter and a second anvil with a ring-shaped molding surface of 50 mm in diameter from which the portion corresponding to the molding surface of the first anvil was removed by a recess. An anvil was used. The clamping pressure was 4 GPa, the amount of rotation in the rotational motion as parallel motion was 128 degrees for the first anvil and 18 degrees for the second anvil, the speed of rotation was 0.2 rpm, and the temperature was room temperature.

In addition, in this experimental example, a tensile test and a hardness test were performed on a sample taken from the processed plate material. The sampling positions and test conditions of each sample are as shown in FIG.

FIG. 28 shows the state of the plate material before processing and the state of the plate material after processing. In addition, the thick dashed line shown in the plate material before processing indicates a virtual line set in advance when performing the introduction process. In addition, the plate material after processing shows a state in which the processing with the first anvil and the second anvil is applied to separate plate materials, but it is already possible to process the same plate material. I go and check.

As can be seen from FIG. 28, in fact, by processing the same plate material, according to the equivalent strain introduction method according to the present embodiment, the volume of the equivalent strain introduction portion formed in one introduction step is larger. Equivalent strain introduction part can be formed over a wide range of the plate material by moving the clamping position by the mold and performing the introduction step over a plurality of predetermined parts of the plate material.

Next, FIG. 29 shows the results of the hardness test. FIG. 29 is a graph showing the relationship between equivalent strain and hardness. As can be seen from FIG. 29, it was confirmed that the hardness increased according to the equivalent strain in both the introduction steps using the first anvil and the second anvil.

Next, FIG. 30 shows the results of the high temperature tensile test. The left figure in FIG. 30 shows the state of the sample after the high temperature tensile test, and the right figure is a graph showing the relationship between the nominal stress and elongation of the sample. As can be seen from FIG. 30, a high elongation rate was confirmed in the region where the introduction step was performed using the first or second anvil. In particular, although the sample obtained from the 5 mm radius region processed by the first anvil was slightly lower, the samples collected from the other regions all showed an elongation rate of over 400%, indicating that superplasticity was present. seen. In particular, it is extremely interesting that superplasticity was observed even though the second anvil only rotated 18 degrees.

[Experimental example 3]
In this experimental example, the equivalent strain introduction method according to the present embodiment is applied by the introduction process according to the second HPT method, especially the example described with reference to FIG. 5, FIG. 22, etc. Regarding the example of introducing the equivalent strain while rotating the metal body M described above, the method of introducing the equivalent strain into the metal body M by one introduction step was examined.

The sample used in the experiment was a round bar with a diameter of 10 x 80 mm. used. Also, two types of samples, a round bar made of A1050 (pure aluminum) and a round bar made of INCONEL718, were used. In the following description, a sample made of A1050 is called an A1050 grid sample, and a sample made of INCONEL718 is called an INCONEL718 grid sample.

FIG. 31(a) shows the deformation of the A1050 grid sample subjected to the introduction step, and FIG. 31(b) shows the distortion of the lattice of the A1050 grid sample. In addition, in FIG. 31(b), some ruled lines are highlighted with markers so that the distortion of the grid can be easily visually determined.

As shown in Fig. 31(a), the A1050 grid sample, which was subjected to only the forward motion of the introduction process under the conditions of a clamping pressure of 1 GPa, a sliding distance of 10 mm, and a surface roughness of the inner surface of the mold of Rz = 30, was visually observed in the upper half. and the lower half were relatively displaced. In addition, as shown in the upper diagram of FIG. 31(b), the lattice pattern drawn so as to intersect the vertical and horizontal lines at right angles to the inside of the sample at this time is obliquely deformed, and the equivalent strain is effectively introduced. It was suggested that

In addition, it was confirmed that the A1050 grid sample, which had been subjected to the reciprocating motion of the introduction step under the same conditions, returned to the drum pattern that was generally symmetrical left and right, as shown in the lower drawing of FIG. 31(b).

By the way, when the introduction step is performed using a mold with a rough inner surface, the metal body is crimped to the inner surface with a strong clamping pressure and adheres to the rough surface. Releasability problems may occur.

Therefore, next, in order to improve releasability, a release resin sheet was attached to the inner surface of the mold, and the introduction step was performed in a state in which the rough surface formed on the inner surface did not substantially function. FIG. 32 shows the difference between samples without and with a release resin sheet.

As a result of performing the introduction process of only the forward movement on the A1050 grid sample, as shown in the upper sample of FIG. Similarly, it can be seen that the internal grid is distorted and equivalent distortion is effectively introduced.

On the other hand, surprisingly, the sample that was subjected to the introduction process without the rough surface functioning had the same external shape as the sample with the rough surface functioning, but the internal grid The result was that almost no distortion was observed.

From this, it was suggested that releasability, which was an issue in this test, could be improved by invalidating the rough surface on the inner surface of the concave portion of the mold or not forming a rough surface. When applied to other examples of the corresponding introduction process, it became clear that the rough surface plays an important role in the introduction of equivalent strain, which is the original purpose.

In addition, although illustration of the test results is omitted, a study was conducted using molds with different surface roughness on the inner surface of the concave portion of the mold. It was shown that good results can be obtained with a thickness of 25 μm to 45 μm. Although this surface roughness can be applied to other HPS and HPT methods, at least the results do not suggest that the surface roughness is essential for other HPS or HPT methods. should be noted.

Next, FIG. 33 shows the state of the sample when the introduction process was performed on the INCONEL718 grid sample with a clamping pressure of 4 GPa, a sliding distance of 10 mm, and a surface roughness of the inner surface of the mold of Rz=30. In FIG. 33, the upper sample is for the forward movement of the introduction process only, and the lower sample is for the reciprocating movement.

As can be seen from the upper diagram of FIG. 33, in the same way as the A1050 grid sample, the INCONEL718 grid sample is also deformed so that the upper and lower halves are displaced from each other. The lattice pattern inside the sample was obliquely deformed, suggesting that the equivalent strain was effectively introduced.

In addition, when the reciprocating motion of the introduction step was performed under the same conditions, it was confirmed that the drum pattern was returned to a substantially symmetrical left-right pattern, as shown in the lower diagram of FIG. 33 .

Next, for the INCONEL718 grid sample shown in the upper diagram of FIG. 33, the hardness and equivalent strain in each part of the sample were confirmed by analyzing on a computer based on the deformation of the grid. The results are shown in FIG.

In FIG. 34, (a) is a diagram showing the state of deformation of the grid, (b) is a contour diagram of hardness, and (c) is a contour diagram of equivalent strain. As shown in FIG. 34, strain is concentrated at the center in the thickness direction, and the strain is applied slightly obliquely. In addition, there is a correlation between the hardness shown in Fig. 34(b) and the equivalent strain shown in Fig. 34(c). .

Next, the effect of the difference in clamping pressure was confirmed. A1050 grid sample was subjected to the introduction process only in the forward pass with different clamping pressures of 0.8 GPa, 1 GPa, and 1.5 GPa, a sliding distance of 10 mm, and a surface roughness of the inner surface of the mold of Rz = 30. did

As a result, as shown in FIGS. 35(a) to 35(c), it was shown that the greater the clamping pressure, the more strain was introduced. In addition, as shown in FIG. 35(c), when a clamping pressure of 1.5 GPa is applied, it was shown that the same level of strain as the result of 4 GPa shown in the upper diagram of FIG. 33 is introduced. .

From these results, in the application of another example of the introduction step according to the second HPT method, when the material is INCONEL718, the clamping pressure is generally 1.0 GPa or more, preferably 1.5 GPa or more, and more preferably 2 GPa or more. was considered appropriate. This result shows that the load can be reduced by about 2 GPa, considering that a clamping force of about 4 GPa is required when processing a plate material made of INCONEL718 by the first HPT method, for example. Also, the upper limit of the clamping pressure is not particularly limited, but in consideration of the strength of the mold and the like, it was considered to be approximately 10 GPa or less, preferably 6 GPa or less, for example 4 GPa or less. In addition, INCONEL718, which was tested as a material, is a nickel-based superalloy that is a high-strength, difficult-to-work material. It was suggested that the method can be applied to the processing of other metal materials.

[Surface property change method]
Next, a technique for changing the surface texture of the metal body processed by each HPS method or each HPT method described above to a desired surface texture will be described.

Each HPS method and each HPT method described so far, regardless of whether or not the volume of the equivalent strain introduction part formed in one introduction process is larger, An equivalent strain introducing portion is formed between one side of the metal body following the first clamping body and the other side of the metal body following the second clamping body as the body moves in parallel relative to each other. It is common in that it includes an introduction step for

In addition, it is conceivable that the first and second pinching bodies for pinching the metal bodies each have a contact surface with the metal bodies, ie, a pinching surface, which is roughened.

However, as described above as a representative example of the introduction process according to the second HPT method, when the introduction process is performed using a mold with a rough surface, it is crimped with a strong clamping pressure. As a result, the rough surface is transferred to the metal body.

The surface portion of the metal body to which the rough surface is transferred (hereinafter also referred to as the transfer surface) poses no particular problem when the metal body is used as a product, as long as it does not affect the function or design of the product. However, in some cases, it may be necessary to adjust the transfer surface to a desired surface property, such as by smoothing or deforming the transfer surface.

However, the hardness of metal bodies that have undergone the introduction process by each HPS method and each HPT method has significantly increased due to miniaturization. In general, it is not easy to arrange the transfer surface to have the desired surface properties.

Therefore, here, a method for changing the surface texture to a predetermined surface texture for the transfer surface of the metal material surface that has been subjected to the process of introducing equivalent strain by each HPS method and each HPT method described above will be described.

In particular, as a feature of the surface texture changing method according to the present embodiment, the surface texture of the surface of the metal material, that is, the surface texture of the transfer surface is obtained by press-contacting the mold body having the mold surface with the desired surface texture. , the temperature, pressure contact force, strain rate, and It is characteristic in that it has a surface property changing step that is performed under elongation increasing conditions.

This surface property changing step is carried out under elongation increasing conditions including at least a temperature, pressure contact force, and strain rate at which elongation of the metal material increases, and this elongation increasing condition is the target for changing the surface property. It can be appropriately set according to the material of the metal body and the degree of refinement of crystal grains.

That is, the conditions for increasing elongation have temperature, contact pressure, and strain rate as their elements. By reducing the , it is possible to increase the elongation of the metal body as compared with the case where the metal body is processed under the predetermined processing conditions.

When performing the surface property changing step, the elongation of the metal body is not particularly limited, and if it is in a state that exhibits a greater elongation than the elongation at room temperature, it is possible to improve the workability. It is preferably carried out under conditions capable of exhibiting quasi-superplasticity mentioned above, or under elongation increasing conditions capable of exhibiting quasi-superplasticity exhibiting an elongation exceeding 200%.

By adopting such a configuration, it is possible to arrange the transfer surface into a desired surface property by utilizing the properties of the metal body derived from the refinement of the crystal grains obtained by the HPS and HPT methods described above. can.

Further, it is more preferable to carry out under elongation increasing conditions in which elongation of the metal body exceeds 400%, that is, under superplasticity development conditions.

By adopting such a configuration, the surface texture of the transfer surface can be more faithfully adjusted by the stamping surface having the desired surface texture.

The surface property changing step may be performed on the metal material alone, provided that the metal body of the transfer surface portion can be deformed while following the stamping surface under the elongation increasing conditions mentioned above. It may be performed simultaneously with other processing steps.

For example, as an example of performing the surface property changing process alone, when adjusting the surface property of a plate-shaped metal material having a transfer surface, the roller surface of a hot rolling roller is used as a stamp surface, and a hot roll is used as a stamp body. A desired surface property may be obtained by pressing a rolling roller against the transfer surface under conditions of increased elongation.

Further, as an example of performing the surface property changing process simultaneously with other processing processes, there is a case where a disk-shaped metal material having a transfer surface is molded into a so-called cup.

Specifically, by performing the cup molding under conditions of increased elongation, the molding process and the surface texture changing process are performed simultaneously, so that the surface texture can be changed to the desired surface texture while the product is being molded. It becomes possible.

Test examples relating to the surface property changing method according to the present embodiment will be described below. In this test example, the case where the surface property changing process is performed simultaneously with other processes that are technically more difficult than the case where the process is performed alone, particularly the case of cup molding, will be referred to. For example, an example using a hot rolling roller will be omitted, but if cup forming is possible, it is of course possible to modify the surface properties by using the hot rolling roller. The metal material used is a plate-like metal body obtained by the first HPS method. It is derived from the state of crystal grains in the metal body, and does not matter whether the HPS method or the HPT method is different.

A plate material made of INCONEL718 with a length of 100 mm, a width of 100 mm, and a thickness of 1 mm was used as a metal body to be processed, and a process of introducing equivalent strain was performed on the metal body by the first HPT method shown in FIGS. 1 to 3 and 11. .

Next, a circular shape with a diameter of 62 mm was cut from the obtained metal body to obtain a disc metal body for use in the surface property changing method according to the present embodiment. On the same metal body, a transfer surface was formed which was transferred by pressing with a pressing body having a rough surface formed on the pressing surface. The surface roughness of the transfer surface was Rz=31 as a result of measurement. In addition, various test samples were taken from the metal body cut from the disk metal body and subjected to various tests. The temperature at which superplasticity is expressed is 800°C or higher, the strain rate is 2×10 ^-2 /s ^-1 or lower, and the stress required for forming when superplasticity is expressed is predicted to be about 0.2 GPa or higher. was done.

Next, by performing cup molding, the surface property changing step was performed simultaneously with the molding process. Specifically, a disk metal body 81 is arranged between an upper die 80a and a lower die 80b of a cup forming apparatus 80 shown in FIG. While applying a clamping force at 80b, the upper die 80a was used as a pressing die, and the lower surface of the upper die 80a was used as a pressing die surface to smoothen the surfaces of the pressed metal bodies. In order to meet the elongation increase condition described above, the disk metal bodies 81 are preheated to 800° C., and the clamping pressure and strain rate are 0.2 GPa or less and 2×10 ⁻² /s ⁻¹ or less, respectively. It was set to the cup forming device 80. The surface roughness of the lower surface of the upper die 80a, which serves as the stamping surface, is Rz=6.3 or less (▽▽▽, Ra=1.6 or less).

As a result, a molded cup 82 having a shape as shown in FIG. 36(c) was obtained.

Next, regarding the inner bottom surface 82a of the cup molded body 82, it was confirmed whether or not the transfer surface formed on the disc metal body 81 was smoothed.

As a result, the surface roughness was Ra=1.1 μm, which is considered to correspond to approximately 4 to 5 μm in Rz, indicating that the inner bottom surface 82a was sufficiently smoothed. In particular, the surface roughness of Ra = 1.1 μm (Rz = 4 to 5 μm) after this processing is a triangular symbol that indicates the degree of surface finish in the field of metal processing, and is smoother than "▽▽: Cutting finish". It was shown that it is possible to modify the surface texture sufficiently to withstand practical use at the level of general metal processing.

As described above, according to the surface texture changing method according to the present embodiment, a stamping surface having a desired surface texture is provided with respect to a transfer surface formed on a metal body processed by each HPS method or each HPT method. When the surface texture of the transfer surface is made to be the desired surface texture by pressing against the stamped body, the elongation of the metal body according to the degree of refinement of the crystal grains derived from each HPS method and each HPT method is increased. By performing the surface texture changing process under conditions of increased elongation with increasing temperature, pressing force, and strain rate, the surface texture of the transfer surface can be changed to a predetermined (desired) surface texture.

As described above, according to the method for introducing equivalent strain according to the present embodiment, the pair of pinching bodies with the metal body interposed follows the first pinching body along with the relative parallel movement of the pair of pinching bodies. A method for introducing equivalent strain, comprising an introduction step of forming an equivalent strain introduction portion between one side of the metal body and the other side of the metal body following the second clamping body, wherein the introduction step is performed once. With respect to the metal body having a larger volume than the equivalent strain introducing portion formed in, the pressing position on the metal body by the pressing body is moved to a predetermined portion of the metal body over a plurality of places Since the introduction step is performed, the metal body having a larger volume than the equivalent strain introduction portion formed in one introduction step can be applied to a wider range without enlarging the equivalent strain introduction device. Equivalent strain can be introduced by

Finally, the description of each embodiment mentioned above is an example of this invention, and this invention is not limited to the above-mentioned embodiment. Therefore, it goes without saying that various modifications other than the above-described embodiments can be made in accordance with the design and the like within the scope not departing from the technical idea of the present invention.

For example, the number of pinching members provided in the equivalent strain introduction device is not limited to one pair, and it is of course possible to provide a plurality of pairs.

10 equivalent strain introduction device 11, 21, 25 first mold 12, 22, 26 second mold 27 third mold 13, 31 upper anvil 14, 32 lower anvil 23, 28 accommodation space 40 first anvil 45 second Anvil 52 Third anvil 61 Split mold L Virtual line M Metal body S Equivalent strain introduction part

Claims (7)

One side of the metal body that follows the first pressure body and the other side of the metal body that follows the second pressure body with the relative parallel movement of the pair of pressure bodies with the metal bodies interposed therebetween. An equivalent strain introduction method comprising an introduction step of forming an equivalent strain introduction portion between
A target position where the introducing step is performed by moving the pinching position on the metal body by the pinching body with respect to the metal body having a volume larger than the equivalent strain introducing portion formed in one introduction step. The introduction step is continuously or intermittently repeated over a plurality of locations along the curved virtual line set on the metal body according to the above, and the equivalent strain introduction part is applied in one direction along the curved virtual line. A method for introducing equivalent strain, characterized by forming . One side of the metal body that follows the first pressure body and the other side of the metal body that follows the second pressure body with the relative parallel movement of the pair of pressure bodies with the metal bodies interposed therebetween. An equivalent strain introduction method comprising an introduction step of forming an equivalent strain introduction portion between
A target position where the introducing step is performed by moving the pinching position on the metal body by the pinching body with respect to the metal body having a volume larger than the equivalent strain introducing portion formed in one introduction step. The introduction step is continuously or intermittently repeated over a plurality of locations on each virtual line while changing the virtual line along a plurality of linear or curved virtual lines set on the metal body according to the linear or curved line A method for introducing an equivalent strain, characterized in that the equivalent strain introducing portion is formed in one direction along a virtual line of a shape . 3. The method of introducing equivalent strain according to claim 1, wherein the parallel motion is a linear motion or a rotary motion with the axis as the direction of the pressing . 3. The method of introducing equivalent strain according to claim 2 , wherein the parallel movement is a rotational movement with the axis being the direction of pressing, and the plurality of imaginary lines are formed concentrically. One side of the metal body that follows the first pressure body and the other side of the metal body that follows the second pressure body with the relative parallel movement of the pair of pressure bodies with the metal bodies interposed therebetween. An introduction step of forming an equivalent strain introduction part between
With respect to the metal body having a volume larger than the equivalent strain introducing portion formed in one introduction step, the pressing position on the metal body by the pressing body is moved to a predetermined portion of the metal body. A method for introducing an equivalent strain in which the introduction step is performed over a plurality of locations,
The metal body has a thickness greater than the thickness in the pinching direction of the equivalent strain introducing portion formed in one introduction step, the parallel movement is a linear movement, and the first pinching body When the metal body is accommodated in the accommodation space formed between the second clamping body and the second clamping body to form the equivalent strain introduction part in layers over a plurality of locations in the thickness direction, the movement of the clamping position is 1. A method of introducing an equivalent strain, characterized by changing a boundary position between the first and second pinching bodies in the pinching direction. A first gripping body that grips a rod-shaped metal body having a constant cross-sectional shape in the longitudinal direction with a predetermined part inserted therethrough, and a second gripping body that grips a rod-shaped metal body with one end side of the remaining portion inserted therethrough. An introduction step of forming an equivalent strain introducing portion in the metal body existing in the boundary area of the first and second gripping bodies as the metal body moves relative to each other in a direction orthogonal to the extending direction of the metal body. A method for introducing an equivalent strain,
With respect to the metal body having a larger volume than the equivalent strain introduction portion formed in one introduction step, the relative position in the extension direction of the metal body with respect to the boundary area is determined by the first holding body and the second A method of introducing an equivalent strain, characterized in that the introduction step is performed at a plurality of locations on a predetermined portion of the metal body by moving the metal body while it is being inserted into the holding body . A method for changing the surface properties of a metal material surface to which equivalent strain has been introduced by the method for introducing equivalent strain according to any one of claims 1 to 6 ,
In order to obtain the desired surface texture of the surface of the metal material by pressing it against a mold body having a mold surface with the desired surface texture, the crystal grains refined due to the method of introducing the equivalent strain are refined. A surface property changing process, characterized in that the surface property changing step is performed under an elongation increasing condition comprising a temperature, a pressure contact force, and a strain rate at which the elongation of the metal material exceeds 200% according to the degree of deformation.

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