JP5632708B2 - Manufacturing method of industrial equipment parts - Google Patents

Description

The present invention is an automobile various arms, knuckle, various links and bumpers, and automobile parts such as door beam, a method of manufacturing the industrial equipment unit products such as a vacuum pump parts and transportation equipment components.

  Conventionally, improvement of fuel consumption has been pursued by reducing the weight of automobile bodies in response to global environmental problems caused by exhaust gas and the like. For this reason, 6000 series aluminum specified in JISH4140 is particularly suitable for structural materials or structural parts of automobiles, especially various arms such as upper arms and lower arms, various links such as knuckles, upper links and lower links, bumpers and door beams. An aluminum alloy forged product made of an alloy (Al—Mg—Si) or the like is used. The 6000 series aluminum alloy forged product has high strength, high toughness, and relatively excellent corrosion resistance. The 6000 series aluminum alloy itself is also excellent in recyclability in that it has few alloying elements and scrap can be easily reused as a 6000 series aluminum alloy melting raw material.

  In addition, 6000 series aluminum alloy forged products are subjected to hot forging (die forging) such as mechanical press and hydraulic press after homogenization heat treatment of 6000 series aluminum alloy cast material, and then solution treatment and quenching treatment and high temperature. A so-called tempering treatment with an aging treatment is performed.

In order to improve the strength and toughness of the aluminum alloy forged product, various efforts have been made to improve the microstructure of the forged product.
For example, in Patent Document 1, the average particle diameter of dispersed particles is reduced to 0.11 μm or less, and the forged aluminum alloy is controlled by restricting the dispersed particles having an average particle diameter to be 13 particles / μm ² or more per unit area. It has been proposed to suppress intergranular corrosion and stress corrosion cracking of products, and to increase strength and toughness.

  Further, for example, in Patent Document 2, in addition to suppressing the generation of coarse crystal grains and making the crystal grains finer, by controlling the ratio of sub-crystal grains in the structure, stress corrosion cracking is suppressed, and high It has been proposed to increase strength and toughness.

  Furthermore, in patent document 3, by making the electrical conductivity of the Al alloy forged article surface after an aging treatment into the range of 41.0-42.5IACS%, content, such as excess Si amount and Cu and Mn, is increased. It has been proposed to guarantee the strength (0.2% proof stress) of an Al alloy forged product of 350 MPa or more, even if it is a strengthened and thinned forged product of a strength member.

Japanese Patent No. 3761180 Japanese Patent No. 3726087 Japanese Patent No. 3766357

Here, in recent years, in order to further reduce the weight of automobile bodies, there has been a demand for further thinning of structural members or structural parts of automobile bodies, particularly automobile parts. And also in the aluminum forgings which comprise an automotive part, the high intensity | strength corresponding to the thinning, high toughness, and high corrosion resistance are calculated | required.
In order to further reduce the thickness of automobile parts, it is conceivable to reduce the thickness of the parts by improving the material strength. However, aluminum forgings manufactured from a 6000 series aluminum alloy have limitations in improving strength, toughness, and corrosion resistance while further reducing the thickness.

  As a material having higher strength than the 6000 series aluminum alloy, there is a 7000 series aluminum alloy (Al-Zn-Mg series) defined in JISH4140. If this is used, the automotive parts can be made thinner and lighter, but the 7000 series aluminum alloy has the disadvantage that it has low corrosion resistance and is susceptible to stress corrosion cracking. It was considered difficult to apply to.

  In addition, parts that make up vacuum pumps such as turbo molecular pumps and parts that make up transportation equipment such as trains and airplanes are required to have high strength, high toughness, and high corrosion resistance. In order to prolong the number of years, it is expected to further improve the strength, toughness and corrosion resistance.

The present invention has been made to solve the above problems, its object is lightweight, and high strength, to provide a manufacturing method of industrial equipment section product having a high toughness and high corrosion resistance is there.

The method of manufacturing an industrial equipment part according to claim 1 is a composite material in which a part or all of a core material using a 7000 series alloy specified in JISH4140 is covered with a surface layer material using a 6000 series alloy specified in JISH4140. The composite material is subjected to hot forging, or the composite material after hot forging is further machined to be formed into a final product shape to be an industrial equipment part .

According to this, it is possible to manufacture an industrial equipment part composed of a core material formed of a 7000 series alloy specified in JISH4140 and a surface material formed of a 6000 series alloy specified in JISH4140 covering the core material. it can. Since this industrial equipment component uses a 7000 series alloy having very high strength as a core material, the strength of the industrial equipment component can be improved. Moreover, since a core material formed of a 7000 series alloy specified in JISH4140 and a surface layer material formed of a 6000 series alloy specified in JISH4140, which covers the core material, were combined to manufacture industrial equipment parts, a 6000 series alloy was produced. Even when a strength equivalent to that of a conventional industrial equipment part manufactured by only the above is obtained, the mass can be reduced, and thus the weight of the industrial equipment part can be reduced. Moreover, since the core material is covered with a surface layer material made of a 6000 series alloy having high toughness and high corrosion resistance, high toughness and high corrosion resistance of industrial equipment parts can be guaranteed.
In some cases, the composite material after hot forging is machined to form the final product shape, making it an industrial equipment part, which makes it difficult to form the final product shape only by hot forging. It is possible to manufacture the industrial equipment parts by the manufacturing method of the present invention.

The manufacturing method of the industrial equipment part according to claim 2 forms a cylindrical core material using a 7000 series alloy specified in JISH4140, and uses the 6000 series alloy specified in JISH4140 to place the core material in its internal space. After forming the fitting cylindrical surface layer material, the manufacturing method of the industrial device part according to claim 1, wherein the fitting dimension between the core material and the surface layer material is- The surface arithmetic average roughness Ra of the outer peripheral surface of the core material and the surface arithmetic average roughness Ra of the inner peripheral surface of the surface layer material are each in the range of 0.05 to 0.40 mm, and 1 to 30 μm. A processing step for processing the core material and the surface layer material, a homogenization heat treatment step for performing a homogenization heat treatment on the core material and the surface layer material, and the core material with the surface layer material. Fit together to cover the composite And, the subjecting the hot forging to the composite, or molded into a final product shape by further machining the composite material after hot forging, characterized in that the industrial equipment parts.

According to this, it is possible to manufacture an industrial equipment part composed of a core material formed of a 7000 series alloy specified in JISH4140 and a surface material formed of a 6000 series alloy specified in JISH4140 covering the core material. it can. Since this industrial equipment component uses a 7000 series alloy having very high strength as a core material, the strength of the industrial equipment component can be improved.
Moreover, since a core material formed of a 7000 series alloy specified in JISH4140 and a surface layer material formed of a 6000 series alloy specified in JISH4140, which covers the core material, were combined to manufacture industrial equipment parts, a 6000 series alloy was produced. Even when a strength equivalent to that of a conventional industrial equipment part manufactured by only the above is obtained, the mass can be reduced, and thus the weight of the industrial equipment part can be reduced. Moreover, since the core material is covered with a surface layer material made of a 6000 series alloy having high toughness and high corrosion resistance, high toughness and high corrosion resistance of industrial equipment parts can be guaranteed.
Furthermore, by making the fitting dimension of the core material and the surface layer material within the range of −0.05 to 0.40 mm, the core material and the surface layer material can be easily fitted, and after the fitting, the core material Since air can be made difficult to enter between the surface layer material and the surface layer material, formation of an oxide film can be prevented.
Furthermore, by setting the surface arithmetic average roughness Ra within the range of 1 to 30 μm, the core material can be easily inserted into the surface layer material, and the forging process can be favorably performed.
In some cases, the composite material after hot forging is machined to form the final product shape, making it an industrial equipment part, which makes it difficult to form the final product shape only by hot forging. It is possible to manufacture the industrial equipment parts by the manufacturing method of the present invention.

The method for manufacturing an industrial equipment part according to claim 3 is the method for manufacturing an industrial equipment part according to claim 1 or 2 , wherein the industrial equipment part is formed into a final product shape to form the industrial equipment part. When the entire surface is formed of a 6000 series alloy specified in the JISH4140, the forged product is subjected to a T6 tempering treatment, and a part of the surface of the industrial equipment part is specified in the JISH4140. In the case of being formed of a 7000 series alloy, a tempering process is performed in which the forged product is subjected to a tempering treatment of T7.

  According to this, the quality of industrial equipment parts can be further improved by performing the tempering process suitable for the material of the surface of a forged product.

According to the method for manufacturing an industrial equipment component according to the present invention, it is possible to manufacture an industrial equipment component that is lightweight and has high strength, high toughness, and high corrosion resistance.

(A) is a perspective view which shows the whole structure of the I-shaped link (automobile component) which is an industrial equipment component which concerns on 1st embodiment of this invention, (b) is a sectional side view of (a). . (A) is a perspective view which shows the whole structure of the I-shaped link (automobile component) which is an industrial equipment component which concerns on 2nd embodiment of this invention, (b) is a sectional side view of (a). . It is a conceptual diagram for demonstrating the forge process in the manufacturing method of the I-shaped link which is an industrial equipment component which concerns on 1st or 2nd embodiment of this invention. (A) is a sectional side view of the composite material obtained when A is selected in FIG. 3, and (b) is a conceptual diagram showing how the composite material of (a) is forged into a final product shape. It is. (A) is a sectional side view of the composite material obtained when B is selected in FIG. 3, and (b) is a conceptual diagram showing how the composite material of (a) is forged into a final product shape. It is. It is a flowchart for demonstrating the manufacturing method of the I-shaped link which concerns on 1st or 2nd embodiment of this invention. It is a perspective view which shows the whole structure of the door beam (automobile component) which is an industrial equipment component which concerns on 3rd embodiment of this invention, (b) is a sectional side view of (a). It is a perspective view which shows the whole structure of the bumper (automobile component) which is an industrial equipment part which concerns on 4th embodiment of this invention, (b) is a sectional side view of (a). It is a conceptual diagram for demonstrating the manufacturing method of the bumper (automobile component) which is an industrial equipment component which concerns on 4th embodiment of this invention. It is a perspective view which shows the whole structure of the axle box (transport equipment part) of the train which is an industrial equipment part which concerns on 5th embodiment of this invention. (A) is a sectional side view of the composite material used in the manufacturing method of the axle box of the train which is an industrial equipment part which concerns on 5th embodiment of this invention, (b) is the composite material of (a). It is a sectional side view of the axle box (final product shape) obtained by forging. It is a perspective view which shows the whole structure of the rotor (vacuum pump component) of the turbo molecular pump which is an industrial equipment component which concerns on 6th embodiment of this invention. It is a conceptual diagram for demonstrating the forge process in the manufacturing method of the rotor of the turbo molecular pump which is an industrial equipment component which concerns on 6th embodiment of this invention. It is the figure which showed the load-displacement curve at the time of implementing a tensile strength test. It is the figure which showed the relationship between the corrosion depth and corrosion amount, and a corrosion cycle at the time of implementing a composite corrosion test.

Hereinafter, the industrial equipment component and the manufacturing method thereof according to the present invention will be described.
Here, industrial equipment parts include various arms such as lower arms and upper arms, various links such as knuckles, upper links and lower links, automobile parts such as bumpers and door beams, rotors constituting vacuum pumps such as turbo molecular pumps, etc. And parts of transportation equipment such as train axle boxes and aircraft leg parts. The method for manufacturing industrial equipment parts of the present invention can be applied to the manufacture of industrial equipment parts as described above, but for the manufacture of I-shaped links (automobile parts) in plan view such as upper links and lower links. Especially easy to apply.

[First embodiment]
Hereinafter, the industrial equipment component according to the first embodiment will be described in detail with reference to FIG. In the following description, an I-shaped link 1A (automobile part) in plan view will be described as an example of the industrial equipment part according to the first embodiment.

First, the structure of the link (automobile part) 1A will be described.
As shown in FIG. 1 (a), the link 1A mainly includes linear arm portions 2a and cylindrical bush insertion portions 3a and 3a provided at both ends of the arm portion 2a. Yes. A bush 30 is press-fitted into the through hole 3a ₁ of the bush insertion portion 3a, and the link 1A is supported by a vehicle body (not shown) via the bush 30.
The bush 30 is used at a connection point between the link 1A and the vehicle body (not shown). For example, the bush 30 is provided on the outside of the small-diameter metal cylindrical member and the small-diameter metal cylindrical member. The rubber cylindrical member is arranged, and a large-diameter metal cylindrical member arranged outside the rubber cylindrical member. The bush 30 is press-fitted into the bush insertion portion 3a by pressing or the like.

As shown in FIG. 1B, the link 1A includes a core material 11 made of a 7000 series alloy (hereinafter also simply referred to as “7000 series alloy”) defined in JISH4140, and a part of the core material 11 or And a surface layer material 12 made of a 6000 series alloy defined in JISH4140 (hereinafter also simply referred to as “6000 series alloy”).
In the first embodiment, a part of the core material 11 is covered with the surface layer material 12, and a part thereof is exposed. Specifically, the core 11 is formed from one and the other end portions in the length direction of the link 1A, that is, the outer end portions of the bush insertion portions 3a and 3a and the surface of the through hole 3a ₁ of the bush insertion portion 3a. Exposed.

The core material 11 serves as a core of the link 1A. In the first embodiment, the arm portion 2a and the bush insertion portion 3a of the link 1A are formed.
Here, the core material 11 can be formed of, for example, 7050 alloy, 7075 alloy, 7N01 alloy, or the like specified in JISH4140. In particular, the use of the 7050 alloy can further improve the strength. Since it can do, it is more preferable.

  The surface layer material 12 covers the core material 11 and is made of a 6000 series alloy specified in JISH4140 having high toughness and high corrosion resistance.

  Here, the surface layer material 12 can be formed of, for example, a 6003 alloy, a 6106 alloy, a 6061 alloy, a 6063 alloy, a 6011 alloy, a 6111 alloy, a 6151 alloy, or a 6N01 alloy defined in JISH4140. The 6061 alloy is more preferable because the corrosion resistance of the link 1A can be further improved.

Here, the thickness of the surface layer material 12 covering the core material 11 is 1.0 mm or more and 2.0 mm or less.
In a corrosion depth survey of a general automobile part market-recovered product, a corrosion amount of about 400 μm is obtained for a 100,000 km traveling vehicle for 10 years. In recent years, the performance of automobiles has been improved, and it has become possible to withstand the use of longer distances and longer distances than the period of use and mileage in the survey results. For this reason, it is preferable that the automobile parts are also designed so that they can withstand long-term use over long distances. In light of the results of the investigation, for example, in a 200,000 km traveling vehicle for 20 years, the amount of corrosion is assumed to be about 800 μm.

In view of this, if the thickness of the surface layer material 12 is less than 1.0 mm, the thickness is too small, and the core material 11 may be exposed when corrosion progresses over time. . On the other hand, if the thickness of the surface layer material 12 is larger than 2.0 mm, the required thickness is greatly exceeded, and accordingly, the weight of the link 1A is undesirably increased.
From the above, when the thickness of the surface layer material 12 covering the core material 11 is 1.0 mm or more and 2.0 mm or less, the core material 11 can be reliably protected by the surface layer material 12 even if corrosion progresses over time. And the weight of the link 1A can be reduced.

<Manufacturing method for industrial equipment parts>
Next, the manufacturing method of the industrial equipment component according to the present invention will be described with reference to FIGS. 3 to 6 and FIG. 1 as appropriate, taking the manufacturing method of the link 1A according to the first embodiment as an example.
In the manufacturing method of the link 1A according to the first embodiment, a part or the whole of the core material using a 7000 series alloy specified in JISH4140 is covered with a surface layer material using a 6000 series alloy specified in JISH4140 to form a composite material. The basic concept is to subject this composite material to hot forging and forming it into a final product shape to obtain an automobile part. Specifically, the link 1A according to the first embodiment can be manufactured by the following two methods.

  First, the manufacturing method of link 1A which concerns on 1st embodiment performs melt | dissolution process S1, casting process S2, processing process S3, homogenization heat treatment process S4, and forging process S5. In the melting step S1, the casting step S2, the processing step S3, and the homogenization heat treatment step S4 described below, any processing of the core material 11 and the surface layer material 12 may be performed first or in parallel. You may go. Further, either the processing step S3 or the homogenization heat treatment step S4 may be performed first.

(Dissolution step S1)
The melting step S1 is a step in which an aluminum alloy whose chemical component content is limited to a predetermined range is melted to form a molten metal.
In this melting step S1, a 6000 series alloy specified in JISH4140 is melted to form a molten metal. Also, a 7000 series alloy specified in JISH4140 is melted to obtain a molten metal.

(Casting process S2)
Casting process S2 is a process of casting an aluminum alloy molten metal into an ingot. Here, a molten alloy of 7000 series alloy is cast into an ingot of a predetermined shape. Also, a molten alloy of 6000 series alloy is cast into an ingot having a shape covering an ingot made of 7000 series alloy. As the casting method, a normal melt casting method such as a continuous casting method, a semi-continuous casting method (DC casting method), or a hot top casting method is appropriately selected.

Specifically, in the casting step S2, a molten alloy of 7000 series alloy is cast into an ingot of a predetermined shape. Also, a molten alloy of 6000 series alloy is cast into an ingot of a predetermined shape.
For example, in the casting step S2, a molten 7000 series alloy is cast into a cylindrical bar-shaped ingot (hereinafter also referred to as “first ingot”). The casting step S2 is a cylindrical rod shape having a length dimension larger than that of the first ingot by casting a molten alloy of 6000 series alloy, and covering the peripheral surface of the surface of the first ingot. Ingot (hereinafter also referred to as “second ingot”). In addition, the shape of a 1st ingot and a 2nd ingot is not restricted to this, It can change suitably. For example, the first ingot may be a rectangular column, and the second ingot may be a cylindrical body that covers the first ingot.
Further, for example, in the casting step S2, a molten 7000 series alloy may be cast to form a cylindrical first ingot, and a molten 6000 series alloy may be cast to form a cylindrical second ingot. In this case, the second ingot is processed into a cylindrical rod shape by the processing step S3.

(Processing step S3)
In the processing step S3, the first ingot and the second ingot are respectively machined to have a predetermined surface arithmetic average roughness Ra with predetermined dimensions (diameter dimension and length dimension). This is a step of forming the first processed member 11a as shown and the second processed member 12a shown in FIG.
In this processing step S3, the second ingot is cut into a predetermined length, and further, the outer surface and the inner surface are cut, so that the outer diameter and the inner diameter become predetermined dimensions and predetermined surface arithmetic average roughness Ra. Thus, the second processed member 12a is obtained. Further, the first ingot is cut so as to be approximately equal to the length of the second ingot, and further, the outer surface is cut to have a predetermined dimension and a predetermined surface arithmetic average roughness Ra. To be the first processed member 11a.

  Here, the relationship between the dimensions of the first processed member 11a and the second processed member 12a and the surface arithmetic average roughness Ra will be described. The 1st process member 11a is accommodated in the cylindrical space of the 2nd process member 12a by the forge process S5 mentioned later. At this time, the first processed member 11a can be inserted into the cylindrical space of the second processed member 12a, and the gap between the outer peripheral portion of the first processed member 11a and the inner peripheral portion of the second processed member 12a. It is necessary to prevent the air from entering. If air enters the gap between the outer peripheral portion of the first processed member 11a and the inner peripheral portion of the second processed member 12a, an oxide film is formed, which makes it difficult to perform solid phase bonding in the forging step S5 described later. It is.

  Considering these, as shown by A in FIG. 3, when the outer diameter of the first processed member 11a is a and the inner diameter of the second processed member 12a is b, the fitting dimension ab is −0. The outer diameter dimension of the first processed member 11a and the inner diameter dimension of the second processed member 12a are adjusted to be 05 mm to 0.40 mm. If ab is less than -0.05 mm, the gap between the outer peripheral portion of the first processed member 11a and the inner peripheral portion of the second processed member 12a becomes too large and air enters, while the fitting dimension a This is because the first processed member 11a cannot be inserted into the cylindrical space of the second processed member 12a when -b is 0.40 mm or more.

  Moreover, surface arithmetic average roughness Ra of the outer peripheral surface of the 1st process member 11a and surface arithmetic average roughness Ra of the internal peripheral surface of the 2nd process member 12a shall be 1-30 micrometers, respectively. According to this, it becomes possible to insert the 2nd process member 12a in the 1st process member 11a, and it becomes possible to perform a solid phase joining favorably in the forge process S5 mentioned later.

(Homogenization heat treatment step S4)
The homogenization heat treatment step S4 is a step of performing a homogenization heat treatment on the first processing member 11a and the second processing member 12a obtained in the processing step S3 under specific conditions.
In the homogenization heat treatment step S4, for example, when the first processed member 11a is made of 7075 alloy or 7050 alloy specified in JISH4140, the holding temperature is raised from the solidus temperature of −100 ° C. to the solidus temperature. Warm, hold at this holding temperature for 23-25 hours, then cool and homogenize heat treatment.
Further, for example, when the second processed member 12a is made of 6061 alloy specified in JISH4140, the temperature is raised to a holding temperature of 450 to 505 ° C., held at this holding temperature for 4 hours, and then cooled and subjected to a homogenization heat treatment. . Alternatively, the temperature is raised to a holding temperature of 506 to 530 ° C., held at this holding temperature for 15 to 17 hours, and then cooled and subjected to a homogenization heat treatment. In addition, when cooling, it cools to room temperature, for example in preparation for the forge process mentioned later.

(Forging process S5)
The forging step S5 is a step in which the composite material 21A is subjected to predetermined hot forging by forging by a mechanical press or forging by a hydraulic press that is normally performed.
First, as a preparation for performing the forging step S5, the first processed member 11a and the second processed member 12a are arranged so as to have a predetermined arrangement relationship. Here, it arrange | positions so that the 2nd process member 12a may coat | cover the 1st process member 11a. Specifically, first, as shown by A in FIG. 3, the first processing member 11a is inserted into the cylindrical second processing member 12a. Thereby, the surrounding surface of the 1st process member 11a is coat | covered with the 2nd process member 12a. Hereinafter, the member thus obtained is referred to as a composite material 21A. In the first embodiment, as indicated by A in FIG. 3, the length dimension of the first processed member 11a and the length dimension of the second processed member 12a are substantially equal, and thus the obtained composite material 21A As shown in FIG. 4A, the end surface of the first processed member 11a and the end surface of the second processed member 12a are substantially flush.

In the forging step S5, it is more preferable to perform forging with a hydraulic press that easily applies the processing distortion of forging per time to the composite material 21A and easily adjusts the processing rate and processing distortion. In the forging step S5, the composite material 21A is heated at 350 ° C. to 460 ° C. and forged at a forging ratio of 3 or more to form the final product shape (near net shape) of the automobile part.
Here, the forging ratio indicates the value s / s ′ of the ratio between the vertical sectional area s of the composite material 21A before forging and the vertical sectional area s ′ of the composite material 21A after forging. That is, here, the composite material 21A is forged so that the vertical cross-sectional area s of the composite material 21A before forging is three times or more the vertical cross-sectional area s ′ of the composite material 21A after forging.
In the forging step S5, if the heating temperature is less than 350 ° C., solid phase diffusion is difficult, whereas if it exceeds 460 ° C., the first processed member 11a formed of a 7000-based alloy (7051 alloy) is melted by heat. This is because there is a risk of losing. In addition, by forging at a forging ratio of 3 or more, solid phase diffusion of the 6000 series alloy and the 7000 series alloy is favorably promoted, and as a result, the solid phase bonding between the core material 11 and the surface layer material 12 is favorably performed. Can do.

In the hot forging, forging (for example, rough forging, intermediate forging, finish forging, etc.) may be performed continuously under the conditions of a predetermined hot forging start temperature and a hot forging end temperature. In this case, the initial forging start temperature corresponds to the hot forging start temperature, and the final forging end temperature corresponds to the hot forging end temperature. Moreover, after hot forging, you may reheat and perform hot forging again.
In the forging step S5, as shown in FIG. 4B, the composite material 21A is forged into a link 1A having a final product shape as shown in FIG.

  By performing the above steps, the link 1A according to the first embodiment is obtained, but the manufacturing method of the link 1A according to the first embodiment may further include a refining step S6.

(Refining process S6)
The tempering step S6 is a step of subjecting the link 1A obtained in the forging step S5 to a tempering treatment of T6 or T7 in order to obtain higher strength, higher toughness and higher corrosion resistance as the link 1A. T6 is a tempering treatment that performs an aging treatment to obtain the maximum strength after solution treatment and quenching. T7 is a tempering treatment in which an excessive aging treatment (overaging treatment) is performed beyond the aging treatment for obtaining the maximum strength after solution treatment and quenching.

  In the tempering step S6, when the entire surface of the link 1A is formed by the surface layer material 12, that is, when the entire core material 11 is covered by the surface layer material 12, the tempering of T6 is performed on the link 1A. On the other hand, when a part of the surface of the link 1A is formed by the core material 11, that is, when a part of the core material 11 is exposed, the tempering process of T7 is performed on the link 1A. I will give it. When the core material 11 is completely covered with the surface layer material 12, it is desirable to apply a tempering treatment of T6 in order to obtain higher strength, while the core material 11 is partially exposed. This is because it is desirable to perform the tempering treatment of T7 in order to guarantee the high corrosion resistance of the link 1A.

In the first embodiment, since a part of the core material 11 is exposed, a tempering process of T6 is performed.
The solution treatment can be performed at a quenching temperature and a holding time that are normally performed using an air furnace, an induction heating furnace, a glass stone furnace, or the like as appropriate. The quenching temperature after the solution treatment is preferably performed by cooling to water or hot water. The aging treatment is performed by an ordinary method using an air furnace, an induction heating furnace, an oil bath, or the like as appropriate.
The forged product may be appropriately subjected to machining or surface treatment desirable as the link 1A before and after the tempering treatment.

According to the link 1A according to the first embodiment obtained by the manufacturing method as described above, the core material 11 formed of a 7000 series alloy having very high strength and the high toughness covering the surface of the core material 11 And the surface layer material 12 formed of a 6000 series alloy having high corrosion resistance, it is lightweight and can guarantee high strength, high toughness and high corrosion resistance.
That is, since the link 1A has the core material 11 formed of a 7000 series alloy having very high strength, even if the strength equivalent to that of a conventional link manufactured using only a 6000 series alloy is obtained, the mass is reduced. As a result, the weight can be reduced. Further, the link 1A is such that the core 11 is covered with a surface layer material 12 formed of a 6000 series alloy having high toughness and high corrosion resistance, and the surface of the link 1A is mainly formed of the surface layer material 12. Therefore, high toughness and high corrosion resistance can be guaranteed.

Here, the link 1A according to the first embodiment, as described above, the end surfaces of the link 1A, the core material 11 is exposed from the through hole 3a ₁ of the surface of the bushing insertion portion 3a. However, the through-holes 3a _1, as described above, the surface of the through hole 3a ₁ is not exposed since the bush 30 is press fitted. For this reason, the deterioration of the corrosion resistance of the link 1A can be prevented. Moreover, since the corrosion resistance of the link 1A can be improved by the tempering step S6, the high corrosion resistance of the link 1A can be guaranteed.

  In addition, according to the manufacturing method of the link 1A according to the first embodiment, the link (automobile part) 1A that guarantees high corrosion resistance (durability) such as high strength, high toughness, and stress corrosion cracking resistance with a simple configuration. Can be manufactured.

[Second Embodiment]
Hereinafter, the industrial equipment component according to the second embodiment will be described in detail with reference to FIG. In the following description, an I-shaped link 1B (automobile part) in plan view is taken as an example of an industrial equipment part according to the second embodiment. The link 1B according to the second embodiment is only different in structure from the link 1A according to the first embodiment. That is, in the link 1A according to the first embodiment and the link 1B according to the second embodiment, the former has a part of the core material 11 exposed from the surface, whereas the latter has the entire surface as a surface material. The only difference is that it is covered with 12. For this reason, about the other common structure, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

<Structure of auto parts>
First, the structure of the link (automobile part) 1B will be described.
As shown in FIG. 2A, the link 1B mainly includes a linear arm portion 2b and cylindrical bush insertion portions 3b and 3b provided at both ends of the arm portion 2b. Yes. A bush 30 is press-fitted into the through hole 3b ₁ of the bush insertion portion 3b, and the link 1B is supported by a vehicle body (not shown) via the bush 30.

As shown in FIG. 2B, the link 1B includes a core material 11 made of a 7000 series alloy prescribed in JISH4140 and a 6000 series alloy prescribed in the JISH4140 covering the core material 11 (hereinafter simply referred to as “7000”). And a surface layer material 12 made of a “base alloy”. In the link 1B of the second embodiment, the entire surface of the core material 11 is covered with the surface layer material 12, and the surface of the link 1B is formed of only the surface layer material 12.
Here, in the arm portion 2b, the surface layer material 12 covering the core material 11 has a thickness of 1.0 mm or more and 2.0 mm or less. In the arm portion 2b, the thickness of the surface layer material 12 covering the core material 11 is set to 1.0 mm or more and 2.0 mm or less, so that the core material 11 can be reliably secured by the surface material 12 even if corrosion progresses over time. The link 1B can be reduced in weight.

<Manufacturing method for industrial equipment parts>
Next, a method for manufacturing an industrial equipment component according to the present invention will be described with reference to FIGS. 3, 5 and 6 and FIG.
As shown in FIG. 6, the manufacturing method of the link 1B according to the second embodiment includes a melting step S1, a casting step S21, a processing step S31, a homogenizing heat treatment step S41, and a forging step S5. is there.
The manufacturing method of the link 1B according to the second embodiment is different from the manufacturing method of the link 1A according to the first embodiment because the contents of the casting process, the processing process, and the homogenization heat treatment process are different. About the process common to the manufacturing method of link 1A which concerns on embodiment, description is abbreviate | omitted suitably using the same code | symbol. Hereinafter, each step will be described in detail. In the melting step S1, the casting step S21, the processing step S31, and the homogenization heat treatment step S41, any processing of the core material 11 and the surface layer material 12 may be performed first or simultaneously. Further, either the processing step S31 or the homogenization heat treatment step S41 may be performed first.

(Casting step S21)
The casting step S21 is a step of casting the molten aluminum alloy to form an ingot. The casting method is the same as the manufacturing method of the link 1A according to the first embodiment.
Specifically, in the casting step S21, a molten alloy of 7000 series alloy is cast into an ingot of a predetermined shape. Also, a molten alloy of 6000 series alloy is cast into an ingot of a predetermined shape.
For example, in the casting step S21, a molten 7000 series alloy is cast into a cylindrical bar-shaped ingot (hereinafter also referred to as “first ingot”). The casting step S2 is a cylindrical bar shape in which a molten alloy of 6000 series alloy is cast, the inner diameter is slightly larger than the diameter of the first ingot, and the length dimension is larger than that of the first ingot. Of the surface of one ingot, an ingot having a shape covering the peripheral surface (hereinafter also referred to as “second ingot”) is used. The casting step S21 further casts a molten alloy of 6000 series alloy and has a diameter substantially equal to that of the first ingot, and a cylindrical second cast having a shape that covers the end surface of the surface of the first ingot. Make a lump. In addition, the shape of a 1st ingot and a 2nd ingot can be suitably changed similarly to the manufacturing method of link 1A which concerns on 1st embodiment.
Further, for example, in the casting step S2, a molten 7000 series alloy may be cast to form a cylindrical first ingot, and a molten 6000 series alloy may be cast to form a cylindrical second ingot. In this case, the second ingot is processed into a cylindrical rod shape by the processing step S3.

(Processing step S31)
In the processing step S31, the first ingot, the second ingot having a shape covering the peripheral surface of the first ingot, and the second ingot having a shape covering the end surface of the first ingot are formed with a predetermined diameter and length. In this step, the first processed member 11b, the second processed member 12a, and the second processed members 12b and 12b are machined so as to have the same size as indicated by B in FIG.
In this processing step S31, the second ingot having a shape covering the peripheral surface of the first ingot is processed into a predetermined length, and further, the outer surface and the inner surface are cut so that the outer diameter and the inner diameter are predetermined. To the second processed member 12a.
Further, the first ingot is processed into a length dimension shorter than the length dimension of the second processed member 12a, and the outer diameter is adjusted to a predetermined dimension by cutting the outer surface. Let it be member 11b.

  Further, the length dimension of the second ingot having a shape covering the peripheral surface of the first ingot with the first processed member 11b is substantially the same as the length dimension of the second processed member 12a. And then cut into two. Then, the outer diameter is adjusted to a predetermined dimension by cutting the outer surface to obtain second processed members 12b and 12b.

(Homogenization heat treatment step S41)
The homogenization heat treatment step S41 is a step of subjecting the machined first processed member 11b, the second processed member 12a, and the second processed members 12b, 12b to a homogenized heat treatment under specific conditions.
In the homogenization heat treatment step S41, for example, when the first processed member 11a is made of 7075 alloy or 7050 alloy specified in JISH4140, the holding temperature is raised from the solidus temperature of −100 ° C. to the solidus temperature. Warm, hold at this holding temperature for 23-25 hours, then cool and homogenize heat treatment.
Further, for example, when the second processed member 12a and the second processed member 12b, 12b are made of 6061 alloy specified in JISH4140, the temperature is raised to a holding temperature of 450 to 505 ° C. and held at this holding temperature for 4 hours. Cool and homogenize heat treatment. Alternatively, the temperature is raised to a holding temperature of 506 to 530 ° C., held at this holding temperature for 15 to 17 hours, and then cooled and subjected to a homogenization heat treatment. In addition, when cooling, it cools to room temperature, for example in preparation for the forge process mentioned later.

(Forging process S5)
First, as a preparation for performing the forging step S5, the first processed member 11a and the second processed member 12a are arranged at predetermined positions.
Here, it arrange | positions so that the 1st process member 11b may be coat | covered with the 2nd process member 12a and the 2nd process members 12b and 12b. Specifically, first, as shown by B in FIG. 3, the first machining member 11b is inserted into the cylindrical inside of the second machining member 12a, and the first machining member 11b is substantially at the center in the length direction. The first processed member 11b is arranged so that the position thereof matches the position of the central portion in the length direction of the second processed member 12a. Next, the second processed members 12b and 12b are second processed from one end side and the other end side of the second processed member 12a so as to sandwich the first processed member 11b from one end side and the other end side. It arrange | positions inside the member 12a. Thereby, the peripheral surface of the 1st process member 11b is coat | covered with the 2nd process member 12a, and the one end part and the other end part in the length direction of the 1st process member 11b are the 2nd process members 12b and 12b. Is covered. Hereinafter, the member thus obtained is referred to as a composite material 21B. In the first embodiment, each member is formed so that the length of the second processed member 12a and the combined length of the first processed member 11b and the second processed member 12b, 12b are substantially equal. In the obtained composite material 21B, as shown in FIG. 5A, the end surface of the second processed member 12a and the end surfaces of the second processed members 12b and 12b are substantially flush.

Then, as in the case of the method for manufacturing the link 1A according to the first embodiment, as shown in FIG. 5 (b), the composite material 21B is forged, and the final product as shown in FIG. 2 (a). Forging into shape (link 1B). Thereby, the link 1B according to the second embodiment is obtained. In addition, you may perform tempering process S6 after forging process S5 similarly to the case of the manufacturing method of link 1A which concerns on 1st embodiment. Further, before or after the tempering step S9, more desirable machining or surface treatment as the link 1B may be appropriately performed.
By performing the above steps, the link 1B according to the second embodiment is obtained.

  As described above, the link 1B according to the second embodiment obtained by the manufacturing method as described above has the entire surface of the core material 11 covered with the surface layer material 12, and therefore the link 1B according to the first embodiment. Higher corrosion resistance (durability) such as stress corrosion cracking resistance can be further ensured than the link 1A.

Moreover, according to the manufacturing method of industrial equipment parts of the present invention, it is possible to manufacture industrial equipment parts that guarantee high corrosion resistance (durability) such as high strength, high toughness, and stress corrosion cracking resistance.
According to the manufacturing method of industrial equipment parts of the present invention, for example, various arms such as a lower arm and an upper arm, knuckle, upper link, automobile parts such as a lower link, a bumper and a door beam, vacuum pump parts, train axle boxes and aircraft legs Parts can be manufactured. The method for manufacturing an industrial equipment part of the present invention is particularly suitable for manufacturing an I-shaped link (automobile part) in plan view such as an upper link or a lower link.

  In the above-described embodiment, the first processed member 11a and the second processed members 12a and 12b are cast by the casting step S2 (S21). However, the present invention is not limited to this, and a 6000 series alloy is extruded. Then, the cylindrical first processed member 11a shown in the first or second embodiment is manufactured, and the cylindrical second processed member 12a shown in the first or second embodiment is produced by extruding the 7000 series alloy. Alternatively, the cylindrical second processed member 12b shown in the second embodiment may be manufactured.

[Third embodiment]
Next, the industrial equipment component according to the third embodiment of the present invention will be described in detail with reference to FIG. The industrial equipment part according to the third embodiment is a door beam (automobile part) of an automobile.
<Door beam structure>
As shown in FIG. 7A, the door beam 1C is a reinforcing member having shock-absorbing performance that is mounted inside the door in order to protect the occupant from a side collision of the vehicle body. As shown in FIG. 7B, the door beam 1C includes a core material 11 made of a 7000 series alloy prescribed in JISH4140, and a surface layer material 12 made of a 6000 series alloy prescribed in JISH4140, which covers the core material 11, It is formed by. For example, the core material 11 can be 7050 alloy, and the surface layer material 12 can be 6061 alloy. The surface layer material 12 covering the core material 11 has a thickness of 1.0 mm or more and 2.0 mm or less. By setting the thickness of the surface layer material 12 covering the core material 11 to 1.0 mm or more and 2.0 mm or less, the core material 11 can be reliably protected by the surface layer material 12 even if corrosion progresses over time. The door beam 1C can be reduced in weight. In addition, the thickness of the core material 11 and the surface layer material 12 is not restricted to this, It can set suitably according to the intensity | strength etc. which are required for the door beam 1C which is a final product.

  Such a door beam 1C can be manufactured using the manufacturing method of the link 1A or 1B described above. For example, the composite material 21A formed by inserting the first processed member 11b into the cylindrical inside of the second processed member 12a used in the manufacturing method of the link 1A described above is shown in FIG. 7B by the forging step S5. The final product shape of the door beam 1C is obtained by forging as described above. Other manufacturing processes are the same as the manufacturing method of the link 1A. Note that when the door beam 1C is manufactured by the manufacturing method of the link 1A, a part of the core material 11 is exposed from both end portions. Do not touch. For this reason, even if a part of the core material 11 is exposed from both ends of the door beam 1C, the corrosion resistance (durability) such as stress corrosion cracking resistance is not affected. The door beam 1C thus obtained is lightweight and has high strength, high toughness, and high corrosion resistance.

[Fourth embodiment]
Next, the industrial equipment component according to the fourth embodiment of the present invention will be described in detail with reference to FIGS. 8 and 9. The industrial equipment part according to the fourth embodiment is an automobile bumper (automobile part).
For example, as shown in FIG. 8A, the bumper 1D is provided at the front end of the vehicle 110. The bumper 1D protects the vehicle body, the occupant, and the load at the time of a collision, and reduces the damage to the colliding opponent. It is a buffer member. For example, as shown in FIG. 8B, the bumper 1D is formed in a substantially rod shape, and both end portions thereof are bent along the shape of the front end of the vehicle body. As shown in FIG. 8B, the bumper 1D includes a core material 11 made of a 7000 series alloy prescribed in JISH4140, and a surface layer material 12 made of a 6000 series alloy prescribed in JISH4140 and covering the core material 11. , Is formed by. The thicknesses of the core material 11 and the surface layer material 12 may be the same as the specific examples described in the above-described third embodiment, and may be appropriately set according to the strength required for the bumper 1D that is the final product.

Next, an example of the manufacturing method of bumper 1D shown in FIG.8 (b) is demonstrated with reference to FIG.
For example, the first ingot and the second ingot are manufactured by the casting step S2 described in the method for manufacturing the link 1A, and the first ingot is formed into a cylinder having a square shape in side view by the processing step S3. A first processed member 11c is used, and the second ingot is used as a second processed member 12c that is a cylindrical body having a square shape when viewed from the side. At this time, when the horizontal width of the outer wall portion of the first processed member 11c is a1, the vertical width is a2, the horizontal width of the inner wall portion of the second processed member 12c is b1, and the vertical width is b2, the fitting dimensions a1-b1, By cutting the outer surface of the first processed member 11c and the inner surface of the second processed member 12c so that a2-b2 is -0.05 mm to 0.40 mm, respectively, the dimension of the first processed member 11c The dimension of the second processed member 12c is adjusted. And the 1st process member 11c is inserted in the rectangular-shaped space of the 2nd process member 12c, and it is set as the composite material 21C. As shown in the left diagram of FIG. 9A, the composite material 21 </ b> C is joined in a state where two composite materials 21 </ b> C are stacked in the vertical direction so as to join the composite materials 21 </ b> C and 21 </ b> C. For example, prismatic cores (not shown) having substantially the same dimensions as the dimensions of the cavities are respectively inserted into the cavities of the first processed members 11c and 11c of the composite materials 21C and 21C. The composite materials 21C and 21C are pushed out by applying pressure from above and below the composite materials 21C and 21C in a state of being overlapped with each other, thereby joining the composite materials 21C and 21C to each other, as shown in the right side of FIG. The final product shape of the bumper 1D having the structure is obtained. The extrusion method described above is merely an example, and can be set as appropriate.

  Further, for example, until one side of the first processed member 11c is exposed by machining such as cutting one side of the four sides of the second processed member 12c that covers the surface of the first processed member 11c in the composite material 21C. The composite material 21D as shown in the left diagram of FIG. 9B is removed. Such a composite material 21D includes a first processed member 11c and a concave second processed member 12d that covers three sides of the first processed member 11c. In a state where two such composite materials 21D are arranged vertically so that one side of the exposed first processed member 11c faces and contacts, so-called extrusion processing is performed to join the composite materials 21D and 21D to each other. 9 (b) Obtain the final product shape of the bumper 1D having the internal structure as shown in the right figure. The extrusion method can be set as appropriate.

Further, for example, the first ingot and the second ingot are manufactured by the casting step S2 described in the method for manufacturing the link 1A, and the first ingot is converted into the first ingot by the processing step S3. As shown in the left figure, the first processed member 11e is a cylindrical body having a “day” shape when viewed from the side, and the second ingot has a square shape when viewed from the side as shown in the middle of FIG. Let it be the 2nd process member 12e which is a cylinder. At this time, when the horizontal width of the outer wall portion of the first processed member 11e is a3, the vertical width is a4, the horizontal width of the inner wall portion of the second processed member 12e is b3, and the vertical width is b4, the fitting dimensions a3-b3, By cutting the outer surface of the first processed member 11e and the inner surface of the second processed member 12e so that a4-b4 is -0.05 mm to 0.40 mm, respectively, The dimension of the second processed member 12e is adjusted. And the 1st process member 11e is inserted in the rectangular-shaped space of the 2nd process member 12e, and it is set as the composite material 21E.
And what is called an extrusion process is given to the composite material 21E, and the final product shape of bumper 1D which has an internal structure as shown to the right figure of FIG.9 (c) is obtained. The extrusion method can be set as appropriate.

According to the example shown in FIGS. 9A to 9C, the bumper 1 </ b> D has the surface of the core material 11 covered with the surface layer material 12 except for both end portions. High corrosion resistance (durability). The bumper 1D thus obtained is lightweight and has high strength, high toughness, and high corrosion resistance.
For example, in the example shown in FIGS. 9A to 9C, the bumper is formed using a composite material in which the entire surface of the first processed member is covered with the second processed member as in the composite material 21B described above. When 1D is manufactured, the entire surface of the core material 11 is covered with the surface layer material 12, so that a bumper 1D having high corrosion resistance (durability) such as stress corrosion cracking resistance can be manufactured.

[Fifth embodiment]
Next, the industrial equipment component according to the fifth embodiment of the present invention will be described in detail with reference to FIGS. The industrial equipment component according to the fifth embodiment is a train axle box (transport equipment component).
The axle box 1E supports an axle (not shown) of a train. As shown in FIG. 10, the axle box 1E is provided so as to project around a cylindrical portion 50 and the cylindrical portion 50, and a bolt (not shown). It has mainly the attachment parts 51 and 51 attached to a vehicle main body (not shown) via this. The attachment portions 51, 51 have a plurality of through holes 51a on the surface for inserting bolts (not shown).

  As shown in FIG. 11B, the axle box 1E includes a core material 11 made of a 7000 series alloy prescribed in JISH4140, and a 6000 series alloy prescribed in the JISH4140 covering the core material 11 (hereinafter simply referred to as “7000”). And a surface layer material 12 made of a “base alloy”. The thicknesses of the core material 11 and the surface layer material 12 may be the same as the specific examples described in the third embodiment described above, and can be appropriately set according to the strength required for the axle box 1E that is the final product. .

Such an axle box 1E can be manufactured using, for example, the manufacturing method of the link 1B described above.
For example, as shown to Fig.11 (a), the 1st process member 11b is inserted in the cylindrical inside of the 2nd process member 12a, and this 1st process member 11b is one edge part side and the other edge part side. The composite material 21B formed by disposing the second processed members 12b and 12b inside the second processed member 12a from one end side and the other end side of the second processed member 12a is forged, and the shaft box 1E Forms a shape that has an external shape. Then, the base material is further subjected to machining such as cutting to form the cylindrical portion 50, and a plurality of through holes 51a (see FIG. 10) are formed on the surfaces of the attachment portions 51 and 51. FIG. The final product shape of the axle box 1E as shown in (b) is obtained.
In addition, when the manufacturing method of the link 1B is used, as shown in FIG. 11B, the entire surface of the core material 11 is covered with the surface material 12, so that the corrosion resistance (durability) such as stress corrosion cracking resistance is high. 1E can be manufactured. The axle box 1E obtained in this way is lightweight and has high strength, high toughness, and high corrosion resistance.

[Sixth embodiment]
Next, industrial equipment parts according to the sixth embodiment of the present invention will be described in detail with reference to FIGS. The industrial equipment component according to the sixth embodiment is a component used for a vacuum pump. Here, a turbo molecular pump rotor will be described as an example of a part used in a vacuum pump.

  First, the structure of the turbo molecular pump will be described with reference to FIG. The turbo-molecular pump 60 is a kind of mechanical vacuum pump, and is a pump that exhausts gas by rotating a rotor 1F, which is a rotating body having metal moving blades, at high speed and blowing off gas molecules. In a cylindrical casing 61 indicated by a broken line in FIG. 1, and a cylindrical body 62 provided along the axial center of the casing 61, and a moving blade (rotary blade) 63 provided to protrude from the surface of the cylindrical body 62. And a rotor 1F.

  The moving blades 63 are formed in a plurality of stages at predetermined intervals along the rotation axis direction of the rotor 1F. Further, between the moving blades 63, 63 arranged vertically, there are interposed stationary blades 64 that protrude from the inner wall surface of the casing 61 toward the moving blade 63 and are formed in a plurality of stages at predetermined intervals. The rotor blade 63 and the stationary blade 64 constitute a turbine blade stage of the turbo molecular pump 60. Although illustration is omitted here, a drag pump stage is provided in the rear stage (downward in the drawing) of the turbine blade stage in the casing 61. Then, gas is sucked from an inlet (not shown) provided at the upper end portion of the casing 61, and this gas is sent in the order of the turbine blade stage and the drag pump stage (not shown), and is provided near the lower end portion of the casing 61. The waste outlet 65 is discharged to the outside of the turbo molecular pump 60.

Next, the structure of the rotor 1F of the turbo molecular pump 60 will be described with reference to FIG.
As shown in FIG. 13B, the rotor 1F includes a core material 11 made of a 7000 series alloy prescribed in JISH4140, and a 6000 series alloy prescribed in JISH4140 covering the core material 11 (hereinafter simply referred to as “7000 series”). And the surface layer material 12 made of an “alloy”. More specifically, in the rotor 1 </ b> F, the cylindrical body 62 is formed of the core material 11, and the moving blade 63 attached around the cylindrical body 62 is formed of the surface layer material 12. For example, the core material 11 can be 7050 alloy, and the surface layer material 12 can be 6061 alloy. The thicknesses of the core material 11 and the surface layer material 12 may be the same as the specific examples described in the above-described third embodiment, and can be appropriately set according to the strength required for the rotor 1F that is the final product.

Such a rotor 1F can be manufactured using, for example, a manufacturing method of the link 1B. That is, the first ingot and the second ingot are manufactured by the casting step S2 described in the method for manufacturing the link 1B, and the first ingot is converted into the first processed member 11f of the cylindrical body by the processing step S3. The second ingot is a cylindrical second processed member 12f and a columnar second processed member 12g. At this time, when the outer diameter of the first processed member 11f is a5 and the inner diameter of the second processed member 12f is b5, the fitting dimension a5-b5 is −0.05 mm to 0.40 mm. The outer surface of the first processed member 11f and the inner surface of the second processed member 12f are cut to adjust the outer diameter of the first processed member 11f and the inner diameter of the second processed member 12f.
Here, the first processed member 11f is lower in height than the second processed member 12f, and has a diameter substantially equal to or slightly smaller than the inner diameter of the cylindrical shape of the second processed member 12f. The second processed member 12g has a height substantially equal to the height from the upper end surface of the first processed member 11f to the upper end surface of the second processed member 12f, and the diameter is a cylindrical shape of the second processed member 12f. It has a diameter that is approximately the same as or slightly smaller than the inner diameter.

  Here, since the rotor 1F has a vertically long shape, as shown in FIG. 13A, the first processed member 11f and the second processed members 12f and 12g are arranged upright. Specifically, as shown in FIG. 13A, the columnar first processed member 11f is inserted into the cylindrical shape of the second processed member 12f. At this time, the first processed member 11f is arranged so that the lower end surface of the first processed member 11f is substantially flush with the lower end surface of the second processed member 12f. And if the 2nd processing member 12g is inserted in the 2nd processing member 12f from the upper direction of the 1st processing member 11f arrange | positioned in this way, the upper end surface of the 2nd processing member 12g will be substantially the upper end surface of the 2nd processing member 12f. It will be the same. In this way, a substantially cylindrical composite material 21F is formed.

  Then, the composite material 21F is forged in the forging step S5 to obtain a shaped material 70 having an approximate outer shape of the rotor 1F as shown by a broken line in FIG. 13B. Then, the raw material 70 is further subjected to machining such as cutting to obtain a final product shape of the rotor 1F indicated by a solid line in FIG.

In the rotor 1F obtained in this way, a part of the side surface of the cylindrical body 62 formed of the core material 11 is covered with the moving blade 63 formed of the surface layer material 12, and therefore the stress corrosion cracking resistance and the like are improved. High corrosion resistance (durability) can be guaranteed. Moreover, the rotor 1F obtained in this way is lightweight and has high strength, high toughness, and high corrosion resistance.
As shown in FIG. 13B, in this embodiment, the surface of the upper end side of the columnar body 62 of the rotor 1F is formed of a 7000 series alloy. The surface may be coated with a 6000 series alloy. According to this, higher corrosion resistance (durability) can be guaranteed.

  Each embodiment has been described above, but the present invention is not limited to the above-described embodiment. For example, industrial equipment parts may be used as aircraft leg parts.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, and may be implemented with appropriate modifications without departing from the scope of the claims. It is also possible.

Example 1
First, 7050 alloy and 6061 alloy were melted and degassed, and cast into a cylindrical ingot by a usual continuous casting method.
Thereafter, the 7050 alloy cast material was chamfered to an outer diameter of 115 mm by machining and cut to a length of 320 mm. Further, the 6061 alloy cast material was chamfered to an outer diameter of 143 mm and an inner diameter of 115 mm and cut to a length of 320 mm.
Further, the 6061 alloy cast material after processing was heated to a holding temperature of 500 ° C., held for 4 hours, then cooled and subjected to a homogenizing heat treatment to obtain a second processed member. In addition, the 7050 alloy cast material after processing is heated to a holding temperature of 450 ° C. and held for 24 hours, further heated to a holding temperature of 475 ° C., held for 16 hours, and then cooled and subjected to a homogenization heat treatment. The first processed member was used.
And a 1st processing member is arrange | positioned inside a 2nd processing member, and it arrange | positions so that the outer peripheral surface of a 1st processing member may be coat | covered with a 2nd processing member, and it is set as a composite material with respect to this composite material. Was used for forging by hot forging with a 6300t press. Then, the forged product was subjected to a T7 tempering treatment to produce an I-shaped link (see FIG. 1) in plan view of Example 1.

(Comparative Example 1)
First, 6061 alloy was melted and degassed to obtain a cylindrical ingot by a continuous casting method.
Also, by machining, the 6061 alloy cast material is chamfered to an outer diameter of 143 mm and cut to a length of 320 mm, heated to a holding temperature of 500 ° C., held for 4 hours, cooled and subjected to a homogenizing heat treatment, Furthermore, hot forging using a mechanical press was performed.

(Comparative Example 2)
First, 7050 alloy was melted and degassed to obtain a cylindrical ingot by a continuous casting method.
Further, by machining, the 7050 alloy cast material is chamfered to an outer diameter of 143 mm and cut to a length of 320 mm, heated to a holding temperature of 450 ° C., held for 24 hours, then heated to a holding temperature of 475 ° C., After holding for 16 hours, it was cooled and subjected to a homogenization heat treatment, and further hot forging using a mechanical press was performed.

  In the hot forging, each composite material was heated from room temperature to the forging start temperature, immediately exited from the furnace, and after confirming the forging start temperature, it was forged into the final product shape (here, I-shaped link). Forging was performed three times continuously without reheating during the process. Immediately after completion of forging, the temperature of the forged product (forging finished temperature) was measured, and then the forged product was allowed to cool to room temperature.

(T6 tempering treatment conditions)
In the solution treatment of the T6 refining treatment, the forged product was held at about 477 ° C. for 3 hours and then quenched in cold water at 60 ° C. After quenching, it was immersed in cold water for 10 minutes as it was, and then immediately subjected to high temperature aging treatment. The high temperature aging treatment conditions were 121 ° C. and 23 hours.
(T7 tempering treatment conditions)
In the solution treatment of the T7 tempering treatment, the forged product was held at 477 ° C. for 3 hours and then quenched in cold water at 60 ° C. After quenching, it was immersed in cold water for 10 minutes as it was, and then immediately subjected to overaging. The excessive aging treatment was performed by two-stage aging of 6 hours at 121 ° C. and 7 hours at 177 ° C.

  The forged products of Example 1 and Comparative Examples 1 and 2 were evaluated for tensile strength, mass, and corrosion resistance.

(Tensile strength)
Tensile strength tests were performed with the bushes pressed into the bush insertion portions of the links of Example 1 and Comparative Examples 1 and 2, respectively. First, the amount of bush displacement and the input load when an external force on the outer side in the radial direction was input to the bush insertion portion were measured. And based on the measurement result, the load-displacement curve shown in FIG. 14 was created, and yield strength and tensile strength (maximum strength) were calculated. The results of calculating the tensile strength (maximum strength) are shown in Table 1.

(mass)
The mass of the link of Example 1 and Comparative Examples 1 and 2 was measured. And the mass of Example 1 and the comparative example 2 when the mass of the comparative example 1 (current material (6061 alloy material)) was made into 100% was computed. The results are shown in Table 1.

(Corrosion resistance)
Bushes were inserted into the bush insertion portions of the links of Example 1 and Comparative Examples 1 and 2, respectively, and these links were put into a composite corrosion tester to perform a corrosion resistance test. The test method was carried out according to JASOM609-91. The corrosion depth from the link surface was measured by micro observation. Here, FIG. 15 is a graph summarizing the relationship between the corrosion depth, the corrosion amount, and the corrosion cycle for each of general low corrosion resistance and high corrosion resistance.

  And it was set as relative evaluation on the basis of the current material (6061 alloy material). The results are shown in Table 1. In addition, the thing with especially excellent corrosion resistance was evaluated as corrosion resistance "(double-circle)", the thing excellent in corrosion resistance was evaluated as corrosion resistance "(circle)", and the thing inferior to corrosion resistance was evaluated as corrosion resistance "*".

  As shown in Table 1, Example 1, which satisfies the claims of the present invention, provides high tensile strength and high corrosion resistance even when the weight is reduced compared to Comparative Examples 1 and 2. It was confirmed.

  On the other hand, it was confirmed that the comparative example 1 manufactured on the manufacturing conditions outside the claim of this invention was inferior in tensile strength compared with Example 1. FIG. In addition, it was confirmed that Comparative Example 1 had a larger mass than Example 1 and was inferior to Example 1 in terms of weight reduction. Moreover, it was confirmed that the comparative example 2 manufactured by the manufacturing conditions outside the scope of the claims of the present invention is significantly inferior in corrosion resistance to that of Example 1.

1A, 1B link (auto parts)
1C Door beam (auto parts)
1D bumper (auto parts)
1E axle box (transport equipment parts)
1F rotor (vacuum pump parts)
2a, 2b arm 3a, 3b bushing insertion portion 3a _1, 3b ₁ through hole 11 first processing core member 12 surface layer material 11a~11f member 12a~12g second processing member 21A~21F composite 30 Bush S1 dissolution step S2, S21 Casting step S3, S31 Processing step S4, S41 Homogenizing heat treatment step S5 Forging step S6 Tempering step

Claims (3)

  Part or all of the core material using a 7000 series alloy specified in JISH4140 is covered with a surface material using a 6000 series alloy specified in JISH4140 to form a composite material, and this composite material is hot forged to form a final product shape A method for manufacturing an industrial equipment part, characterized in that the composite material after hot forging is further processed into a final product shape by further machining. After forming a cylindrical core material using a 7000 series alloy specified in JISH4140, and forming a cylindrical surface material that fits the core material into its internal space using a 6000 series alloy specified in JISH4140, An industrial equipment part manufacturing method for manufacturing an industrial equipment part comprising the core material and the surface layer material covering a part or all of the core material ,
The fitting dimension between the core material and the surface layer material is in a range of −0.05 to 0.40 mm, and the surface arithmetic average roughness Ra of the peripheral surface of the core material and the surface layer material A processing step of processing the core material and the surface layer material so that the surface arithmetic average roughness Ra of the peripheral surface is in the range of 1 to 30 μm, respectively.
A homogenization heat treatment step of subjecting the core material and the surface layer material to a homogenization heat treatment;
The core material is fitted to the surface layer material to form a composite material, and the composite material is subjected to hot forging and formed into a final product shape, or the composite material after hot forging is further machined to complete the process. A manufacturing method of an industrial equipment part, characterized by performing a forging step of forming into a product shape and making the industrial equipment part. After forming the final product shape into the industrial equipment part, if the entire surface of the industrial equipment part is formed of the 6000 series alloy specified in JISH4140, the forged product is subjected to a tempering treatment of T6. When a part of the surface of the industrial equipment part is formed of the 7000 series alloy specified in JISH4140, a tempering process is performed in which the forged product is subjected to a tempering treatment of T7. The manufacturing method of the industrial equipment part of Claim 1 or Claim 2 to do.

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