JPWO2004022805A1 - High strength copper alloy - Google Patents

Abstract

The present invention is a high-strength copper alloy that is excellent in mechanical properties, workability, corrosion resistance, etc., and has no problem in economy, and contains 4 to 19 mass% Zn and 0.5 to 2.5 mass% Si. The alloy composition contains Zn-2.5 · Si = 0 to 15 mass% between the contents and the balance is Cu, and the average grain size D is 0.3 μm ≦ D ≦ Disclosed is a rolled material having a crystal structure of 3.5 μm and a 0.2% proof stress in a recrystallized state of 250 N / mm 2 or more.

Description

  The present invention relates to a high-strength copper alloy suitable as a constituent material for leads, switches, connectors, relays, sliding pieces and the like used in electrical, electronic, communication, information, measuring equipment, automobiles and the like.

Generally, high-strength copper alloys are used as components for leads, switches, connectors, relays, sliding pieces, etc. used in electrical, electronic, communications, information, measuring instruments and automobiles. As such devices become smaller, lighter, and higher in performance, structural materials such as leads, switches, connectors, and the like used for them are required to have extremely strict characteristics. For example, a very thin plate is used for the spring contact portion of the connector, and the high strength copper alloy that constitutes such a thin plate requires a high strength in order to reduce the thickness, and further has a high strength and bending workability. It has a high balance with ductility such as the beginning, excellent productivity and economy, and conductivity, corrosion resistance (stress corrosion cracking resistance, dezincification resistance, migration resistance), stress relaxation characteristics, solderability, resistance There is a demand for no problem in wear and the like.
By the way, as high-strength copper alloys, generally, beryllium copper, titanium copper, aluminum bronze, phosphor bronze, white, brass, brass added with Sn, Ni are well known, but these general high-strength copper alloys Has the following problems and cannot meet the above-mentioned requirements.
That is, beryllium copper has the highest strength among copper alloys, but beryllium is very harmful to the human body (especially in the molten state beryllium vapor is extremely dangerous even if it is a very small amount). For this reason, it is difficult to dispose (particularly incineration) a beryllium copper member or a product containing the member, and the initial cost required for the melting equipment used for production becomes extremely high. Accordingly, there is a problem in economic efficiency including manufacturing cost, in combination with the necessity of solution treatment at the final stage of manufacturing in order to obtain predetermined characteristics.
Titanium copper has the second strength next to beryllium copper. However, since titanium is an active element, expensive melting equipment is required, and quality and yield at the time of melting becomes a problem. Therefore, as with beryllium copper, there is a problem in economic efficiency in combination with the necessity of solution treatment at the final stage of production.
Moreover, since aluminum is an active element, aluminum bronze has a problem that it is difficult to obtain a sound ingot and that solderability is poor.
In addition, phosphor bronze and white are generally manufactured by horizontal continuous casting because they have poor hot workability and are difficult to manufacture by hot rolling. Therefore, productivity is poor, energy costs are high, and yield is poor. Moreover, since the high-strength representative varieties such as spring phosphor bronze and spring western white contain a large amount of expensive Sn and Ni, there is a problem in economy.
Brass and brass added with Si and Ni are inexpensive, but they are not satisfactory in strength and have problems with corrosion resistance (stress corrosion cracking and hypothetical zinc corrosion). It is unsuitable as a constituent material.
Therefore, such a general high-strength copper alloy is not completely satisfactory as a component material for various devices that tend to be reduced in size, weight, and performance as described above. Development is strongly demanded.

The present inventor found that 0.2% proof stress (the strength when the permanent strain becomes 0.2%, and may be simply referred to as “proof strength” hereinafter) is −1/2 to the crystal grain size D. (D ^-1/2 Hall-Petch relational expression (EO Hall, Proc. Phys. Soc. London. 64 (1951) 747. and NJ Petch, J Focusing on Iron Steel Inst. 174 (1953) 25.), it is considered that a high-strength copper alloy that can satisfy the requirements of the above era can be obtained by refining the crystal grains. Various researches and experiments were conducted on the miniaturization of. As a result, refinement of the crystal grains can be realized by recrystallizing the copper alloy depending on the additive element, and 0.2% proof stress is mainly achieved by refining the crystal grains (recrystallized grains) to a certain extent. It has been found that the strength can be significantly improved, and the strength increases as the crystal grain size decreases. Furthermore, various experiments were conducted on the influence of additive elements in the refinement of crystal grains. The addition of Si to the Cu—Zn alloy has the effect of increasing the nucleation site, and further to the Cu—Zn—Si alloy. Therefore, the addition of Co has an effect of suppressing grain growth. By using these effects, a Cu—Zn—Si alloy or a Cu—Zn—Si—Co alloy having fine crystal grains is obtained. I found out that it was possible. That is, the increase in nucleation sites is considered to be caused by a decrease in stacking fault energy due to Si addition, and the suppression of grain growth is considered to be caused by the formation of fine precipitates due to Co addition.
The present invention has been made on the basis of such investigations, and is a new high-strength copper alloy that is excellent in mechanical properties, workability, corrosion resistance, etc., and has no problem in economy. An object of the present invention is to provide a high-strength copper alloy that can be suitably used as a component material of various devices that tend to be improved in performance and performance, and can be used in a wide range of applications and is extremely practical.
That is, firstly, the present invention is mainly suitable for a rolled material (plate material, strip material, wire material, etc.) or a processed material (press-formed product, bent product, etc.) that requires high strength. An object is to provide a copper alloy (hereinafter referred to as “first invention copper alloy”). In addition, products and parts that can be suitably used as a constituent material of the copper alloy of the first invention include electronic parts and medical equipment used in portable and small communication devices and personal computers that are required to be thin and lightweight. Parts, apparel parts, machine parts, heat exchanger tube sheets, seawater cooling devices and components for seawater intake and outlet in small vessels, wiring equipment parts, various equipment parts for automobiles, measuring equipment parts, play equipment In addition, there are connectors, relays, switches, sockets, springs, gears, pins, washers, amusement coins, keys, tumblers, buttons, hooks, fasteners, diaphragms, bellows, sliding pieces, etc. Examples include bearings, volume sliding pieces, bushes, fuse grips, lead frames, instrument panels, and the like.
Secondly, the present invention mainly does not require strength to the extent required for the first invention copper alloy, but it requires a highly balanced strength and conductivity (plate material, It is an object of the present invention to provide a high-strength copper alloy (hereinafter referred to as “second invention copper alloy”) suitable as a strip material, a wire material, etc.) or a processed material thereof (press-formed product, bent product, etc.). In addition, products and parts that can suitably use the copper alloy of the second invention as a constituent material include various equipment parts for automobiles, information equipment parts that require conductivity, measuring equipment parts, home appliance parts, heat exchangers, etc. There are tube plates, seawater cooling devices, seawater intake and outlet components for small ships, machine parts, play equipment, daily necessities, etc. Specifically, connectors, switches, relays, bushes, fuse grips, lead frames , Wiring devices, keys, tumblers, buttons, hooks, fasteners, diaphragms, bellows, sliding pieces, bearings, and coins for play.
Further, thirdly, the present invention mainly includes a wire drawing material (general wire with a circular cross section, a square cross section (such as a square), a polygon) that requires high strength equivalent to that of the first invention copper alloy. It is an object of the present invention to provide a high-strength copper alloy (hereinafter referred to as “third invention copper alloy”) suitably used as a deformed wire (such as hexagonal shape) or a processed material (bending product or the like). In addition, products and parts that can suitably use the copper alloy of the third invention as a constituent material include medical equipment parts, architectural parts, clothing parts, machine parts, play goods, various equipment parts for automobiles, measuring equipment parts, and electronics. , Electrical equipment parts, etc. Specifically, connectors, keys, header members, nails (nails for play equipment, etc.), washers, pins, screws, coil springs, lead screws, copier shafts, wire mesh (for aquaculture) And a cooling device using a wire mesh or seawater, a seawater intake and outlet filter in a small ship, etc.), a sliding piece, a bearing, a bolt, and the like.
Thus, the first invention copper alloy comprises 4-19 mass% (preferably 6-15 mass%, more preferably 7-13 mass%) Zn and 0.5-2.5 mass% (preferably 0.9- 2.3 mass%, more preferably 1.3 to 2.2 mass%) of Si and the content of Zn-2.5 · Si = 0 to 15 mass% (preferably 1 to 12 mass%, more preferably 2-9 mass%), and the balance is Cu, and the average crystal grain size D is 0.3 μm ≦ D ≦ 3.5 μm (preferably 0.3 μm ≦ D ≦ 2). 0.5 μm, more preferably 0.3 μm ≦ D ≦ 2 μm), and 0.2% proof stress in the recrystallized state is 250 N / mm. ² Or more (preferably 300 N / mm ² This is the basic configuration.
In addition, the copper alloy of the second invention is composed of 4 to 17 mass% (preferably 5 to 13 mass%, more preferably 6 to 11.5 mass%) Zn and 0.1 to 0.8 mass% (preferably 0.2 to 0). .6 mass%, more preferably 0.2 to 0.5 mass%) between Si and Zn-2.5.Si = 2 to 15 mass% (preferably 4 to 12 mass%, more preferably 5). 10 mass%) and the balance is made of an alloy composition consisting of Cu, and the average crystal grain size D is 0.3 μm ≦ D ≦ 3.5 μm (preferably 0.3 μm ≦ D ≦ 3 μm, More preferably, the crystal structure is 0.3 μm ≦ D ≦ 2.5 μm), and the 0.2% yield strength in the recrystallized state is 250 N / mm. ² Or more (preferably 300 N / mm ² This is the basic configuration.
Further, the copper alloy of the third invention comprises 66 to 76 mass% (preferably 68 to 75.5 mass%) of Cu, 21 to 33 mass% (preferably 22 to 31 mass%) of Zn and 0.5 to 2 mass% (preferably 0.8 to 1.8 mass%, more preferably 1 to 1.7 mass%) of Si, and Cu-5 · Si = 62 to 67 mass% (preferably Cu-5 · Si = 63) between these contents. -66.5 mass%) and Zn + 6 · Si = 32 to 38 mass% (preferably Zn + 6 · Si = 33 to 37 mass%). The crystal structure is 0.3 μm ≦ D ≦ 3.5 μm (preferably 0.3 μm ≦ D ≦ 3 μm, more preferably 0.3 μm ≦ D ≦ 2.5 μm). 0.2% proof stress is 250 N / mm ² Or more (preferably 300 N / mm ² This is the basic configuration.
The average grain size D and 0.2% proof stress in each invention copper alloy are the final values when the recrystallization treatment, which is a heat treatment for recrystallizing a part or all of the alloy structure, is performed a plurality of times. Specified by the average crystal grain size and 0.2% proof stress in the material (hereinafter referred to as “recrystallized material”) obtained by the recrystallization process (hereinafter referred to as “final recrystallization process”). is there. In addition, when the said recrystallization process is performed only once, it cannot be overemphasized that the process is a final recrystallization process, and the processing material is a recrystallization material.
Each invention copper alloy is in a preferred embodiment,
(1) The ingot is processed into a predetermined shape by plastic working including hot working (rolling, extrusion, forging, etc.) and / or cold working (rolling, wire drawing), and the plastic working material is recrystallized in the recrystallization temperature range. Recrystallized material obtained by recrystallization treatment (final recrystallization treatment) by heat treatment (annealing, etc.) (mainly, the first and second invention copper alloys are rolled materials, and the third invention copper alloy is drawn). Wire)
(2) Cold worked material obtained by cold working (rolling, drawing, forging) the recrystallized material of (1) above into a predetermined shape (mainly the first and second invention copper alloys are rolled materials) The third invention copper alloy is a wire drawing material),
(3) Product processed material obtained by processing the recrystallized material of (1) above into a predetermined product shape by pressing, bending, or the like,
(4) Product processed material obtained by processing the cold processed material of (2) above into a predetermined product shape by pressing, bending or the like,
Provided in any form.
In the first invention copper alloy, in order to further improve the characteristics, 0.005 to 0.5 mass% (preferably 0.01 to 0.3 mass%, more preferably 0.02 to 0.2 mass). %) Co and / or 0.03-1.5 mass% (preferably 0.05-0.7 mass%, more preferably 0.05-0.5 mass%) of Sn. It is preferable to make it.
In this case, the Co and Sn contents are determined in consideration of the Si content within the above range. That is, the Co content is a value obtained by dividing this by the Si content. Co / Si is 0.005 to 0.5 (preferably Co / Si = 0.01 to 0.3, more preferably Co / Si = 0.03 to 0.2). The Sn content is determined so that the value Si / Sn obtained by dividing the Si content by the content is 1.5 or more (preferably Si / Sn ≧ 2, more preferably Si / Sn ≧ 3). The
In the first invention copper alloy, 0.005-0.3 mass% (preferably 0.01-0.2 mass%) Fe and / or 0.005-0.3 mass% (preferably 0.01- 0.2 mass%) Ni can be used as a substitute element for Co or as an additive element with Co.
In this case, the Fe content or the Ni content is determined in consideration of the Si content (when co-added with Co, the Si content and the Co content). That is, the Fe, Ni content is a value obtained by dividing the total content including the case where Co is contained by the Si content (Fe + Ni + Co) / Si is 0.005 to 0.5 (preferably (Fe + Ni + Co) / Si is determined to be 0.01 to 0.3, more preferably (Fe + Ni + Co) /Si=0.03 to 0.2). In making this determination, the total content (Fe + Ni + Co) is 0.005 to 0.55 mass% (preferably 0.01 to 0.35 mass%, more preferably 0.02 to 0.25 mass%). It is desirable to take this into consideration.
In the second invention copper alloy, in order to further improve the characteristics, 0.005 to 0.5 mass% (preferably 0.01 to 0.3 mass%, more preferably 0.02 to 0.2 mass). %) Co and / or 0.2 to 3 mass% (preferably 1 to 2.6 mass%, more preferably 1.2 to 2.5 mass%) of Sn. Is preferred.
In this case, the Co content and the Sn content are determined in consideration of the relationship with the Si content. That is, the Co content is a value obtained by dividing the Co content by the Si content within the above range, and Co / Si is 0.02 to 1.5 (preferably Co / Si = 0.04 to 1, more preferably Is determined to be Co / Si = 0.06 to 0.5). In addition, within the above range, the Sn content is a value obtained by dividing the Si content by the Sn content, and Si / Sn is 0.5 or less (preferably Si / Sn ≦ 0.4, more preferably Si / Sn ≦ 0.3).
In the copper alloy of the second invention, 0.005 to 0.3 mass% (more preferably 0.01 to 0.2 mass%) Fe and / or 0.005 instead of Co or together with Co. 0.3 mass% (more preferably 0.01 to 0.2 mass%) of Ni can be contained. In this case, the Fe content or the Ni content is determined in consideration of the Si content (when co-added with Co, the Si content and the Co content). That is, the Fe, Ni content is a value obtained by dividing the total content including the case of containing Co by the Si content (Fe + Ni + Co) / Si is 0.02 to 1.5 (preferably (Fe + Ni + Co) / Si). = 0.04-1, more preferably (Fe + Ni + Co) /Si=0.06-0.5). In making this determination, the total content (Fe + Ni + Co) is 0.005 to 0.55 mass% (preferably 0.01 to 0.35 mass%, more preferably 0.02 to 0.25 mass%). It is desirable to take this into consideration.
In the first and second invention copper alloys, P, Sb, As, Sr, Mg, Y, Cr, La, Ti, Mn, Zr, In, and Hf depending on the properties required for the application. One or more elements selected from can be contained. The content of these elements is appropriately determined in the range of 0.003 to 0.3 mass%.
In the third invention copper alloy, in order to further improve the characteristics, 0.005 to 0.3 mass% (preferably 0.01 to 0.2 mass%, more preferably 0.02 to 0.15 mass). %) Co and / or 0.03 to 1 mass% (preferably 0.05 to 0.7 mass%, more preferably 0.05 to 0.5 mass%) of Sn. It is preferable to keep it.
In this case, the contents of Co and Sn are determined in consideration of the Si content within the above range. That is, the Co content is a value obtained by dividing this by the Si content. Co / Si is 0.005 to 0.4 (preferably Co / Si = 0.01 to 0.2, more preferably Co / Si = 0). 0.02 to 0.15). Further, the Sn content is determined so that a value Si / Sn obtained by dividing the Si content by the content is 1 or more (preferably Si / Sn ≧ 1.5, more preferably Si / Sn ≧ 2). The
In the copper alloy of the third invention, 0.005 to 0.3 mass% (preferably 0.01 to 0.2 mass%) Fe and / or 0 as an alternative element to Co or as a co-additive element with Co. 0.005 to 0.3 mass% (preferably 0.01 to 0.2 mass%) of Ni can be contained.
In this case, the Fe content or the Ni content is determined in consideration of the Si content (when co-added with Co, the Si content and the Co content). That is, the Fe, Ni content is a value obtained by dividing the total content including the case of containing Co by the Si content (Fe + Ni + Co) / Si is 0.005 to 0.4 (preferably (Fe + Ni + Co) / Si). = 0.01 to 0.2, more preferably (Fe + Ni + Co) /Si=0.02 to 0.15). In making such a determination, the total content (Fe + Ni + Co) is 0.005 to 0.35 mass% (preferably 0.01 to 0.25 mass%, more preferably 0.02 to 0.2 mass%). It is desirable to take this into consideration.
In the third invention copper alloy, 0.005 to 0.2 mass% of P, Sb and As, respectively, and 0.003 to 0.3 mass% of Sr, Mg, Y, Cr, La, Ti, In the case where one or more elements selected from Mn, Zr, In and Hf are contained in accordance with the properties required for the application, P, Sb and As are contained in a total content of 0.005 to 0.005. The alloy composition further contained can be made so as to be 0.25 mass%.
By the way, as described above, the strength, particularly 0.2% proof stress, is improved by refining crystal grains (recrystallized grains). However, when the inventor has confirmed through experiments, the average crystal grain diameter D is 3.5 μm. In the following cases, a significant improvement in proof stress was recognized as compared with the case of exceeding 3.5 μm. Further, when the average crystal grain size D was gradually reduced from 3.5 μm, it was confirmed that the degree of improvement in proof stress suddenly changed when it reached 3 μm, 2.5 μm, and 2 μm. From the confirmation items by such experiments, the proof stress (generally, 250 N / mm required for component components such as electricity, electronics, communication, and measuring equipment) ² Or more, preferably 300 N / mm ² The average crystal grain size D is required to be 3.5 μm or less in order to ensure the above), and preferably 3 μm or less when high strength (proof stress) is required. Further, when a higher strength is required, it is considered to be preferably 2.5 μm or less. In particular, in order to dramatically improve the strength within a possible range, the average crystal grain size D is set to 2 μm or less. It is considered to be preferable. On the other hand, the proof stress will be improved as the average crystal grain size D becomes smaller. However, as confirmed by experiments, the minimum average crystal grain size is 0.3 μm. Expected to be difficult to obtain.
From this point, in the first to third invention copper alloys, 250 N / mm ² Or more (preferably 300 N / mm ² In order to secure the yield strength of (above), it is necessary to have a recrystallized structure of 0.3 μm ≦ D ≦ 3.5 μm. That is, the average crystal grain size D in the recrystallization state (the state after the final recrystallization treatment) is 0.3 μm ≦ D ≦ 3.5 μm and the 0.2% proof stress is 250 N / mm. ² That is necessary. In the second and third invention copper alloys, it is preferable that 0.3 μm ≦ D ≦ 3 μm, and 0.3 μm ≦ D ≦ 2.5 μm when higher strength is required. Is more preferable. On the other hand, for the first invention copper alloy that is also used for applications that require higher strength than the second and third invention copper alloys, 0.3 μm ≦ D ≦ 2.5 μm is set. Is preferable, and 0.3 μm ≦ D ≦ 2 μm is more preferable.
In addition, the first to third invention copper alloys are obtained by recrystallizing by appropriate heat treatment (generally annealing), and the above-mentioned crystal grain refinement is realized. It becomes possible by setting it as an alloy composition.
That is, in the first to third invention copper alloys, Zn and Si reduce the stacking fault energy, increase the dislocation density, increase the number of recrystallized grain formation nuclei (locations), and refine the crystal grains. It has a function that contributes and a function that contributes to the improvement of material strength by dissolving in the Cu matrix (hereinafter, both functions are referred to as “crystal grain refinement / strength improvement function”), and their contents Is determined as described above for the following reason.
That is, in the first and second invention copper alloys mainly used as a rolled material or product processed material thereof, in order to sufficiently exhibit the function of grain refinement and strength improvement by Zn content, 4 mass% or more is necessary, and in order to exert the function more effectively, the first invention copper alloy which aims to greatly improve the strength is made 6 mass% or more (preferably 7 mass% or more), and the first invention In the second invention copper alloy which is allowed to be slightly inferior in strength to the copper alloy, it is preferably set to 5 mass% or more (preferably 6 mass% or more). On the other hand, if the Zn content is excessive, the stress corrosion cracking susceptibility increases and the bending workability also decreases. Therefore, considering the relationship between the use of the rolled material and the content of Si having the function of suppressing stress corrosion cracking, the Zn content is 19 mass% or less (preferably 15 mass% or less, more preferably, in the first invention copper alloy). Is 13 mass% or less), and in the second invention copper alloy, it is necessary to be 17 mass% or less (preferably 13 mass% or less, more preferably 11.5 mass% or less).
On the other hand, the crystal grain refinement / strength improvement function due to the Si content is exhibited in a much smaller amount than Zn, but is due to the interaction with Zn. Si also has the effect of improving and suppressing stress corrosion cracking by co-addition with Zn. However, excessive addition of Si will lower the conductivity. In consideration of these points, in the first invention copper alloy whose main purpose is strength improvement and crystal grain refinement, the Si content needs to be 0.5 mass% or more, and 0.9 mass% or more (more Preferably, it is preferably set to 1.3 mass% or more. However, in the first invention copper alloy, if Si is added in excess of 2.5 mass%, the conductivity, hot workability and cold workability deteriorate, and in order to sufficiently secure these characteristics, Si The content is preferably set to 2.3 mass% or less, and more preferably set to 2.2 mass% or less. On the other hand, in the copper alloy of the second invention in which importance is placed on the balance between strength and conductivity, the Si content is set to at least 0.1 mass% in order to exert the effect of crystal grain refinement necessary for obtaining a predetermined strength. It is necessary to set it to 0.2 mass% or more. However, in order to ensure a predetermined conductivity in consideration of the balance with strength, it is necessary to keep the Si content at 0.8 mass% or less, and in order to ensure sufficient conductivity commensurate with the application. Is preferably set to 0.6 mass% or less (more preferably 0.5 mass% or less).
Furthermore, in the first and second invention copper alloys, it is necessary to balance the effect of grain refinement by co-addition of Zn and Si with the stress corrosion cracking property and strength. It is not sufficient to determine the content independently in the above-mentioned range, and the mutual relationship between Zn and Si content is specified by Zn-2.5 · Si, and the value of the relational expression is constant. It is necessary to determine the range. That is, in order to ensure a predetermined strength by crystal grain refinement, it is necessary for the first invention copper alloy to satisfy Zn-2.5 · Si ≧ 0 mass%, and Zn−2.5 · Si ≧ 1 mass. % (More preferably Zn−2.5 · Si ≧ 2 mass%). In the second invention copper alloy, Zn−2.5 · Si ≧ 2 mass% is required, and Zn-2. 5 · Si ≧ 4 mass% (more preferably, Zn−2.5 · Si ≧ 5 mass%) is preferable. On the other hand, in any of the first and second invention copper alloys, when Zn-2.5 · Si> 15 mass%, stress corrosion cracking occurs remarkably, so the Zn and Si contents are reduced to Zn-2.5. It is necessary to determine that Si ≦ 15 mass%. In order to more effectively suppress stress corrosion cracking, Zn-2.5 · Si ≦ 12 mass% (more preferably, the first invention) It is preferable to determine such that Zn-2.5 · Si ≦ 9 mass% for the copper alloy and Zn-2.5 · Si ≦ 10 mass% for the second invention copper alloy.
Further, in the copper alloy of the third invention, the Zn content of course considers the function of crystal grain refinement and strength improvement as in the first and second invention copper alloys. Since the copper alloy is mainly used as a wire drawing material or a product processed material thereof, it is necessary to determine it in consideration of hot extrudability, as compared with the first and second invention copper alloys that are rolled materials. The amount should be large, and in order to sufficiently secure the hot extrudability, it is necessary to set it to 21 mass% or more. In order to make hot extrusion-drawing more favorable, the Zn content is more preferably set to 22 mass% or more. Although the third invention copper alloy has a higher Zn content than the first and second invention copper alloys, the stress corrosion cracking resistance is inferior, but a general Cu—Zn alloy (for example, As compared with JIS-C2700 (65Cu-35Zn)), the Zn content is small, and the resistance to stress corrosion cracking can be sufficiently satisfied for use as a wire or the like. However, in the third invention copper alloy, in order to ensure sufficient and sufficient stress corrosion cracking resistance and cold workability as a wire or the like, the Zn content needs to be 33 mass% or less. That is, if the Zn content exceeds 33 mass%, the β phase and γ phase are likely to remain, which adversely affects cold workability, and also causes problems in terms of stress corrosion cracking and dezincification corrosion. In order to perform hot extrusion-drawing more satisfactorily while ensuring stress corrosion cracking resistance and cold workability, the Zn content is preferably set to 31 mass% or less. In the copper alloy of the third invention, it is necessary to consider the Cu content in order to ensure hot extrudability and cold workability. If the Cu content is less than 66 mass%, the β phase and the γ phase are likely to remain, If cold workability becomes a problem and conversely exceeds 76 mass%, hot extrusion becomes difficult. Accordingly, the Cu content needs to be 66 to 76 mass%, and is preferably 68 to 75.5 mass% in order to sufficiently secure cold workability and hot extrudability.
Further, Si, as described above, exhibits the function of grain refinement / strength improvement and the improvement / suppression function of stress corrosion cracking by co-addition with Zn. Therefore, in the third invention copper alloy which is a wire drawing material, the Si content must be 0.5 mass% or more as in the case of the first invention copper alloy, with a focus on the function of grain refinement and strength improvement. Considering that it is a wire drawing material, it is preferably 0.8 mass% or more, and most preferably 1 mass% or more. However, when the Si content exceeds 2 mass%, γ phase and β phase, which are factors that inhibit cold workability, are precipitated. Therefore, in order to ensure cold workability, the Si content needs to be 2 mass% or less, and considering that Zn is contained in a large amount, it is preferably 1.8 mass% or less, It is more preferable to set it as 1.7 mass% or less.
Furthermore, in order to sufficiently ensure hot extrudability, cold workability, and stress corrosion cracking resistance in the copper alloy of the third invention, it is only necessary to independently determine the contents of Cu, Si, and Zn. It is insufficient, and it is necessary to determine the relationship between the Si content, the Cu content, and the Zn content, and Cu-5Si = 62 to 67 mass% in the mutual relationship between the Cu and Si contents, and Zn, It is necessary to determine the Cu, Si, and Zn contents so that Zn + 6 · Si = 32 to 38 mass% in the mutual relationship of the Si contents. That is, even if the Cu, Si, and Zn contents are within the above ranges, the mutual relationship between the Cu and Si contents is Cu-5Si> 67 mass%, or the mutual relationship between the Zn and Si contents is Zn + 6. When Si <32 mass%, good hot workability cannot be ensured. Conversely, when Cu-5Si <62 mass% or Zn + 6 · Si> 38, the Zn and Si concentrations at the grain boundaries are It becomes high or the β phase and γ phase easily remain, so that the cold workability is deteriorated, and further, stress corrosion cracking is likely to occur, and depending on the application, the problem of dezincification corrosion is likely to occur. Furthermore, Cu-5Si = 63-66.5 mass% and Zn + 6 · Si = 33-37 mass are required to ensure sufficient cold workability, stress corrosion cracking resistance, etc. without causing such problems. It is preferable to determine the Cu, Si, and Zn contents so as to be%.
By the way, the crystal grains grow as the humidity rises or as time elapses. In the recrystallization process, the recrystallization process does not recrystallize all parts at the same time, but recrystallizes from the easy recrystallized parts. It takes a long time for crystallization to begin and recrystallization across the entire structure to be completed. For this reason, crystal grains recrystallized in the early stage of the recrystallization process start to grow before the recrystallization process is completed, and grow considerably when the entire structure is completely recrystallized. Therefore, in order to distribute fine recrystallized grains uniformly throughout the entire structure, it is preferable to suppress the growth of recrystallized grains in the recrystallization process. Co has a function of suppressing the growth of recrystallized grains, and this is the reason why Co is added to the first to third invention copper alloys. That is, Co combines with Si to form fine precipitates (about 0.01 μm of Co ₂ Si, etc.) are formed to suppress the growth of crystal grains. In order to exhibit the function of suppressing the growth of crystal grains due to Co, the Co content needs to be 0.005 mass% or more. However, the total amount of Co added does not contribute to the formation of the precipitates described above, and the heat resistance of the matrix is improved and the stress relaxation characteristics are improved by a part of the Co that is dissolved. Therefore, in order to sufficiently exhibit such functions of improving heat resistance and stress relaxation properties, the Co content should be 0.01 mass% or more in any of the first to third invention copper alloys. More preferably, it is more preferably 0.02 mass% or more. On the other hand, even if Co is added in an amount exceeding 0.5 mass% in the first and second invention copper alloys, and Co is added in an amount exceeding 0.3 mass% in the third invention copper alloy, Saturation of required crystal grain growth suppression effect and stress relaxation property is saturated, it does not improve any further, it is economically wasteful, and on the other hand, bending due to coarsening of precipitates and excessive amount of precipitates There is a risk of reducing the performance. Accordingly, the Co content needs to be 0.5 mass% or less in the first and second invention copper alloys, and 0.3 mass% or less in the third invention copper alloy. In order to exhibit each function more effectively and sufficiently ensure the bending workability required for the application, it is preferable to set it to 0.3 mass% or less in the first and second invention copper alloys. .2 mass% or less is more preferable, and in the third invention copper alloy, it is preferably 0.2 mass% or less, and more preferably 0.15 mass% or less.
In addition, since Co has a close relationship with Si in the refinement of crystal grains, it is necessary to determine the Co content in relation to the Si content. In order to improve the strength, the Co content should be set so that the ratio Co / Si to the Si content is 0.005 or more in the first and third invention copper alloys, and in the second invention copper alloy. Needs to be determined to be 0.02 or more. That is, when Co / Si does not reach these values, the formation of the precipitate is small, and the effect of suppressing the growth of crystal grains is not exhibited, and the strength required for the use of the copper alloy of the present invention is obtained. Is difficult. Further, in order to sufficiently exhibit the crystal grain growth suppressing effect and further improve the strength, Co / Si is preferably 0.01 or more in the first and third invention copper alloys. More preferably, it is 02 or more. In the second invention copper alloy, it is preferably 0.04 or more, and more preferably 0.06 or more.
Thus, Co should be determined so that Co / Si is not less than a certain value as described above in relation to the Si content. However, when Co / Si becomes larger than necessary, the coarseness of the precipitates is increased. This leads to an increase in the amount and the amount of increase, and hinders the bending workability. For example, when Co / Si exceeds 0.5 in the first invention copper alloy which is a rolled material and exceeds 0.4 in the third invention copper alloy which is a wire drawing material or a product processed material thereof, bending workability is increased. Decreases rapidly. Also, in the second invention copper alloy used for applications where it is not necessary to improve the strength to the extent required by the first invention copper alloy, it is required when the Co / Si exceeds 1.5. It becomes difficult to ensure the minimum bending workability. Therefore, the upper limit value of Co / Si should be determined in consideration of the use, processing history, and shape of the copper alloy according to the present invention, while considering the above point and the effect of suppressing grain growth by Co. Specifically, the range of Co / Si is determined as follows. That is, the upper limit of Co / Si needs to be Co / Si ≦ 0.5 in the first invention copper alloy, preferably Co / Si ≦ 0.3, and Co / Si ≦ It is optimal to set it to 0.2. In the second invention copper alloy, it is necessary to satisfy Co / Si ≦ 1.5, preferably Co / Si ≦ 1, and most preferably Co / Si ≦ 0.5. is there. In the copper alloy of the third invention, it is necessary to satisfy Co / Si ≦ 0.4, preferably Co / Si ≦ 0.2, and Co / Si ≦ 0.15. Is optimal.
Fe and Ni exhibit the same crystal grain suppression effect as that of Co (more precisely, the effect of Fe and Ni is equal to or less than that of Co). Therefore, Fe and Ni can be contained as substitute elements for Co. Of course, further improvement of the above effect can be expected by co-adding Fe and Ni with Co. When Fe and / or Ni is added instead of Co or together with Co, the economic effect by reducing the content of expensive Co is great. Relationship between Fe, Ni content and Si content (Co + Fe + Ni) / Si in the case of containing Fe and Ni is the same reason and basis as described above for Co / Si Therefore, in any of the first to third invention copper alloys, the Fe and Ni contents are the same as the Co contents, and (Fe + Ni + Co) / Si is also the same as Co / Si. That is, (Fe + Ni + Co) / Si is 0.005 to 0.5 (preferably 0.01 to 0.3, more preferably 0.002 to 0.2) in the first invention copper alloy. 0.02 to 1.5 (preferably 0.04 to 1, more preferably 0.06 to 0.5) for alloys, 0.005 to 0.4 (preferably 0.01 for copper alloys of the third invention) To 0.2, more preferably 0.02 to 0.15). By the way, since Fe and Ni can be substituted elements for Co and perform the same function as Co, even when two or more of Fe, Ni and Co are co-added, the total content thereof is included. The amount should be equivalent to the content in the case where only Co is added alone (the content of Co described above). However, when co-adding two or more of Fe, Ni, and Co, the upper limit of the co-addition content (total content) of Fe, Ni, and Co is greater than the Co content, considering solid solution and precipitation. An enlargement of about 0.05 mass% is allowed. From this point, when two or more of Fe, Ni, and Co are co-added, the total content (Fe + Ni + Co) is set to a range in which the upper limit is expanded by 0.05 mass% with respect to the Co content. It was desirable. That is, the total content (Fe + Ni + Co) is 0.005 to 0.55 mass% (preferably 0.01 to 0.35 mass%, more preferably 0.02 to 0.25 mass) in the first and second invention copper alloys. In the third invention copper alloy, it is preferably 0.005 to 0.35 mass% (preferably 0.01 to 0.25 mass%, more preferably 0.02 to 0.2 mass%). Desirable.
Sn exhibits a strength improving function, a crystal grain refining function, a stress relaxation characteristic, a corrosion resistance, a wear resistance improving function, and the like. Thus, in the first and third invention copper alloys, in order to sufficiently exert the function of improving the strength, the function of refining crystal grains, the function of improving the heat resistance of the matrix, the stress relaxation property, the corrosion resistance, and the wear resistance. And Sn content needs to be 0.03 mass% or more, and it is preferable to set it as 0.05 mass% or more. However, if the Sn content exceeds 1.5% in the first invention copper alloy which is a rolled material, and exceeds 1 mass% in the third invention copper alloy which is a wire drawing material, the bending workability rapidly decreases. Therefore, in order to ensure bending workability, it is necessary that the Sn content be 1.5 mass% or less for the first invention copper alloy and 1 mass% or less for the third invention copper alloy. Further, in both the first and third invention copper alloys, in order to ensure sufficient bending workability, the Sn content is preferably set to 0.7 mass% or less, and is set to 0.5 mass% or less. Is optimal.
On the other hand, in the second invention copper alloy whose required minimum strength is lower than that of the first and third invention copper alloys, considering the relationship with the Si content, the strength improvement by adding Sn, the refinement of crystal grains, the stress It is preferable to improve relaxation characteristics, stress corrosion cracking resistance, corrosion resistance, and wear resistance, but for that purpose it is necessary to keep the Sn content at 0.2 mass% or more, and the required strength Accordingly, it is preferably set to 1 mass% or more, more preferably 1.2 mass% or more. However, when Sn is added exceeding 3 mass%, hot workability is hindered and bending workability is also deteriorated. Therefore, in order to ensure such workability, the Sn content needs to be 3 mass% or less, and in order to ensure better hot workability and bending workability, it is set to 2.6 mass% or less. It is preferable to set it to 2.5 mass% or less.
Moreover, when adding Sn, the content needs to consider the relationship (Si / Sn) with Si content. In the first invention copper alloy whose main purpose is strength improvement, when Si content is increased to obtain high strength, ductility including bending workability should be less than Si / Sn <1.5. Will be significantly reduced. Therefore, in the first invention copper alloy, it is necessary to determine the Sn content so that Si / Sn ≧ 1.5, and in order to sufficiently secure the ductility, Si / Sn ≧ 2 should be set. It is preferable that Si / Sn ≧ 3 is optimal. Further, in the third invention copper alloy in which the Sn content is suppressed to be slightly smaller than the first invention copper alloy, for the same reason as described above, it is necessary to determine the Sn content so that Si / Sn ≧ 1, In order to ensure sufficient ductility, it is preferable to set Si / Sn ≧ 1.5, and it is optimal to set Si / Sn ≧ 2.
On the other hand, in the copper alloy of the second invention that requires electrical conductivity balanced with strength, since it is restricted by the addition of Si, in order to ensure high strength without greatly impairing ductility, Sn content is included. It is necessary to determine the amount so that Si / Sn ≦ 0.5 in relation to the Si content. In order to further improve the ductility and strength, Si / Sn ≦ 0.4 is preferable and Si / Sn ≦ 0.3 is optimal.
P, Sb, As, Sr, Mg, Y, Cr, La, Ti, Mn, Zr, In, and Hf are added according to the use of the alloy, and mainly refinement of crystal grains, heat It exhibits effects such as improvement of inter-workability, improvement of corrosion resistance, action of making harmful trace elements (S and the like) inevitably mixed in harmless, and improvement of stress relaxation characteristics. Such an effect can hardly be expected when the content of each element is less than 0.003 mass%. Conversely, even if the content exceeds 0.3 mass%, an effect commensurate with the addition amount cannot be obtained, and economically. It is useless, and on the contrary, bending workability is impaired. However, in the third invention copper alloy having a high Zn content, P, Sb and As are added for the purpose of improving the dezincification corrosion resistance and stress corrosion cracking resistance. The effect of P, Sb, As added for such a purpose is hardly exhibited by addition of less than 0.005%, as in the above case. On the other hand, when the P content exceeds 0.2 mass%, the cold bending workability is impaired. Therefore, when adding P, Sb, As in the copper alloy of the third invention, the content must be 0.005 to 0.2 mass%, and two or more of P, Sb, As are required. In the case of co-addition, the total content needs to be 0.005 to 0.25 mass%.
By the way, as a heat treatment (recrystallization treatment) for obtaining a recrystallized material, generally, annealing by holding the plastic working material referred to in (1) above at 200 to 600 ° C. for 20 minutes to 10 hours is employed. . Such heat treatment is usually performed in a batch system, but when the heat treatment time is long, recrystallized in the initial stage of the heat treatment grows gradually even if the effect of suppressing the crystal growth by Co addition is exhibited. There is a risk that uniform refinement of crystal grains may be hindered. However, when there is such a possibility, when adding Co by performing a heat treatment (rapid high temperature heat treatment) of the molding material at a temperature higher than the general annealing temperature (molding material temperature) and for a short time. Of course, even when not added, the growth of initial recrystallized grains can be prevented and the crystal grains can be finely refined by recrystallization. That is, by applying high thermal energy in a short time, there is no time margin for recrystallization at a larger number of nucleation sites almost simultaneously in a short time and crystal growth. Specifically, for example, the plastic working material is subjected to heat treatment (rapid high temperature heat treatment) at 450 to 750 ° C. for 1 to 1000 seconds to completely recrystallize the crystal structure of the molding material. To do.
The first to third invention copper alloys are generally manufactured as (1) recrystallized material, (2) cold worked material or (3) (4) product processed material as described above. By adding the following treatment in the manufacturing process, the alloy identification such as strength can be further improved.
For example, in the cold working before obtaining the recrystallized material, the working rate is set to 30% or more (preferably 60% or more). Specifically, in the step of obtaining the plastic working material described in (1), rolling is performed. By carrying out cold working with a rate or wire drawing ratio of 30% or more (preferably 60% or more), the refinement of crystal grains is promoted and the strength improvement by refinement of crystal grains is more effectively achieved. Can do. In other words, the nucleation sites are necessary to make the crystal grains finer, but as described above, the nucleation sites increase due to the cold working with a high processing rate, and the higher the processing rate, the more the nucleation sites. The amount of increase increases. Furthermore, since recrystallization is due to the release of strain energy, finer crystal grains can be obtained by increasing the shear strain by the cold working, resulting in refinement of the crystal grains. The strength can be improved more effectively. By the way, it is preferable that the plastic processing material to be subjected to the final recrystallization treatment has a small average crystal grain size (average crystal grain size before recrystallization). Specifically, the average crystal grain size is 20 μm or less ( It is preferable that the thickness is preferably 10 μm or less. This is because the smaller the average crystal grain size before recrystallization, the greater the number of locations that become recrystallization nuclei in the subsequent heat treatment, and in particular, the higher the dislocation density at the grain boundaries, the more likely to become nucleation sites. However, since the strength increases as the average crystal grain size decreases, the energy cost required for manufacturing a high-strength copper alloy is high and the manufacturing time is also long. Therefore, it is preferable to determine the average crystal grain size of the plastically processed material referred to in (1) in consideration of the above-described processing rate. In addition, if the strength is insufficient if the recrystallized material remains as it is, the strength can be further increased by subjecting the recrystallized material to cold rolling or cold drawing at a processing rate of 10 to 60%. Obtainable.
Furthermore, when the plastic working material is obtained, when one-pass rolling or wire drawing is performed, the reduction ratio and wire drawing ratio should be set large (15% or more (preferably 25% or more)). Is preferred. This is because cold working with a high rolling reduction and drawing rate can increase shear strain and nucleation sites, and further refine the recrystallized grains. Also, the rolling process can be performed with a small-diameter roll or conversely an extremely large-diameter roll, or the wire-drawing process can be performed with a large-diameter wire drawing die or conversely with a large die angle with a very small wire-drawing die. It is effective in increasing the nucleation site or local strain energy and realizing further refinement of recrystallized grains. Furthermore, performing rolling by the different circumferential speed rolling method, that is, rolling while changing the speed with a rolling mill using upper and lower rolls having different diameters, gives a large shear strain to the material to be rolled, Miniaturization can be achieved.
In addition, each invention copper alloy is subjected to an appropriate heat treatment (generally annealing at 150 to 600 ° C. for 1 second to 4 hours) that does not recrystallize depending on its use, etc. The relaxation characteristics can be remarkably improved. Specifically, the cold-worked material of (2) (including the cold-worked material referred to in (4)) or the product-worked material of (3) and (4), for example, at 200 ° C. for 2 hours or 600 ° C. , Heat treatment is performed for 3 seconds.

As Example 1, copper alloys having the compositions shown in Tables 1 to 4 were dissolved in the air to obtain prismatic ingots having a thickness of 35 mm, a width of 80 mm, and a length of 200 mm. Then, the ingot is hot-rolled (4 passes) at 850 ° C. to obtain an intermediate plate having a thickness of 6 mm, pickled, and further made into a final plate having a thickness of 1 mm by cold rolling, and then each final plate. Is subjected to a heat treatment (annealing) for 1 hour at a temperature at which it is recrystallized 100% (hereinafter referred to as “recrystallization temperature”), that is, a complete recrystallization treatment of the structure is performed. . 101-No. 186 was obtained. In addition, in performing the recrystallization treatment, the specimens (square plate pieces having a side of about 20 mm on each side) collected from each final plate material are annealed in advance from 300 ° C. to 50 ° C. for 1 hour, The lowest temperature when the sample piece was completely recrystallized was found and determined as the recrystallization temperature (see Tables 15 to 17).
Further, the alloy No. 102, no. 107, no. 111, no. 154, no. In addition to obtaining a final plate material having the same quality (same shape and same composition) as the constituent materials of 180, the final plate material was recrystallized under conditions different from the above, and alloy no. 102, no. 107, no. 111, no. 152, no. The first invention copper alloy No. 1 having the same composition as 175, respectively. 102A, no. 107A, no. 111A, no. 154A, no. 1805A was obtained. That is, the first invention copper alloy No. 102A, no. 107A, no. 111A, no. 154A, no. In 180A, the final plate is recrystallized (rapidly heated at a high temperature) for a short time by being heated to a temperature much higher than its recrystallization temperature, and its temperature a (° C.) and heating time b ( Second) is as described in “a (b)” in the “recrystallization temperature” column of Tables 15-17. For example, in Table 15, No. Although “480 (20)” is described in the “recrystallization temperature” column of 102A, this means that the final plate is heated and held at 480 ° C. for 20 seconds.
Moreover, as Example 2, the copper alloys having the compositions shown in Tables 5 to 8 were dissolved in the air to obtain prismatic ingots having a thickness of 35 mm, a width of 80 mm, and a length of 200 mm. Then, the ingot is hot-rolled (4 passes) at 850 ° C. to obtain an intermediate plate having a thickness of 6 mm, pickled, and further made into a final plate having a thickness of 1 mm by cold rolling, and then each final plate. Is subjected to a heat treatment (annealing) for 1 hour at a temperature at which it is recrystallized 100%, that is, a recrystallization temperature (by recrystallization treatment). 201-No. 281 was obtained. The recrystallization temperature was determined in advance in the same manner as in the first example (see Tables 18 to 20).
Further, the alloy No. 202, no. 209, no. 250, no. In addition to obtaining a final plate material of the same quality as the constituent material of H.265, the final plate material was subjected to the rapid high-temperature heat treatment described above and recrystallized, so that alloy No. 265 was obtained. 202, no. 209, no. 250, no. No. 265 of the second invention copper alloy no. 202A, no. 209A, no. 250A, No. 265A was obtained. That is, each alloy No. No. 202A, no. 209A, no. 250A, No. The rapid high-temperature heat treatment conditions (temperature a (° C.) and heating time b (seconds)) from which 265A was obtained are shown in the column of “recrystallization temperature” in Tables 18 to 20 in the same manner as in Tables 15 to 17. Is described as “a (b)”.
Further, as Example 3, alloys having the compositions shown in Tables 9 to 12 were melted in the atmosphere to obtain a cylindrical ingot having a diameter of 95 mm and a length of 180 mm. The ingot was heated to 780 ° C., and a round bar with a diameter of 12 mm was obtained by an extrusion press (500 t). This round bar was wire-drawn to 8 mm after cleaning, further heat-treated at 500 ° C. for 1 hour, and then wire-drawn after cleaning to obtain a 4 mm-diameter wire (molded material). . Each wire was heat-treated (annealed) for 1 hour at a temperature at which it recrystallizes 100% (recrystallization temperature) (by recrystallization treatment). 301-No. 397 was obtained. In addition, before performing the recrystallization treatment, a specimen piece (a wire piece having a length of about 20 mm (4 mm diameter)) collected from each wire is annealed in advance from 300 ° C. to 50 ° C. for 1 hour. Then, the lowest temperature when the sample piece was completely recrystallized was found, and this was determined as the recrystallization temperature (see Tables 21 to 24).
In addition, alloy No. 302, no. 314, no. In addition to obtaining a wire material (molded material) having the same quality as that of the constituent material of 338, the final plate material was subjected to the above-described rapid high-temperature heat treatment and recrystallized. 302, no. 314, no. 3rd invention copper alloy No. 3 having the same composition as 338, respectively. 302A, no. 314A, no. 338A was obtained. Each alloy No. 302A, no. 314A, no. The rapid high temperature heat treatment conditions (temperature a (° C.) and heating time b (seconds)) from which 338A was obtained are shown in the column of “recrystallization temperature” in Tables 21 to 24 in the same manner as in Tables 15 to 17. Is described as “a (b)”.
As Comparative Example 1, the same first comparative example alloy No. 1 shown in Table 13 was prepared by the same process as in the first example. 401-No. 422 was obtained. Further, as Comparative Example 2, the second comparative example alloy No. having the composition shown in Table 14 was obtained by the same process as in the third example. 423-No. 431 was obtained. The first comparative alloy No. 401-No. No. 407 has the same composition as JIS standards C2100, C2200, C2300, C2400, C2600, C2680 and C4250, respectively. 423 and no. 424 has the same composition as JIS standard C2600 and C2700, respectively. In Tables 1 to 12, “(Co + Fe + Ni) / Si” for those containing Co but not containing Fe or Ni is read as “Co / Si”.
By the way, Comparative Example Alloy No. 421, no. 425, no. As for 427, No. 431, the following problems occurred in the manufacturing process, and the subsequent process could not be performed. That is, no. No. 421 has a large crack in the stage of hot rolling the ingot. For No. 425, hot extrusion was not possible. 427 and no. No. 431 was broken in the wire drawing process, and none of them could perform the subsequent process, so the production was abandoned.
And 1st invention copper alloy No.1. 101-No. 186, no. 102A, no. 107A, no. 111A, no. 154A, no. 180A, No. 2 copper alloy No. 2 201-No. 281; 202A, no. 209A, no. 250A, No. 265A and the third invention copper alloy No. 301-No. 397, no. 302A, no. 314A, no. 338A and the first and second comparative alloy Nos. 401-No. The average crystal grain size D (μm) in the recrystallized structure of No. 431 (excluding No. 421, No. 425, No. 427, No. 431 for which production was abandoned) was determined by a cutting method using an optical image (JIS-H0501). ). The results were as shown in Tables 15 to 26.
The first invention copper alloy No. 101-No. 186, no. 102A, no. 107A, no. 111A, no. 154A, no. 180A and the second invention copper alloy No. 201-No. 281; 202A, no. 209A, no. 250A, No. 265A and the first comparative example alloy No. 401-No. Conductivity was measured for 422 (excluding No. 421). The results were as shown in Tables 15 to 20 and Table 25. The electrical conductivity (% IACS) is a percentage ratio of a value obtained by dividing the volume specific resistance (17.241 × 10 −9 μΩ · m) of international standard annealed copper by the volume specific resistance of the alloy.
The first invention copper alloy No. 101-No. 186, no. 102A, no. 107A, no. 111A, no. 154A, no. 180A and the second invention copper alloy No. 201-No. 281; 202A, no. 209A, no. 250A, No. 265A and the first comparative example alloy No. 401-No. For 422 (excluding No. 421), a tensile test was performed using an Amsler universal testing machine, and the yield strength (0.2% yield strength), tensile strength and elongation were measured. Further, each alloy was cold-rolled (30% rolling) to a thickness of 0.7 mm, and the rolled material (hereinafter referred to as “post-processed material”) was subjected to the same tensile test as described above, and the proof stress (0. 2% yield strength), tensile strength and elongation were measured, and bending workability evaluation and stress corrosion cracking test were performed. The results were as shown in Tables 15 to 20 and Table 25. The first invention copper alloy No. 101-No. 186, no. 102A, no. 107A, no. 111A, no. 154A, no. 180A and the second invention copper alloy No. 201-No. 281; 202A, no. 209A, no. 250A, No. Needless to say, the post-processed material obtained by rolling 265A 30% is also a high-strength copper alloy according to the present invention.
The bending workability is evaluated by bending a specimen piece cut out from a post-processed material perpendicularly to the rolling direction into a W shape and bending degree R / t (R : The radius of curvature (mm) on the inner peripheral side in the bent portion, t: the plate thickness (mm) of the test piece. In Table 12 to Table 17 and Table 22, what was not cracked at R / t = 0.5 is indicated by “◎” as being excellent in bending workability, and crack was observed at R / t = 1.5. Those that did not occur but cracked at 0.5 ≦ R / t <1.5 are indicated by “◯” as having good bending workability (no practical problem), and R / t = 2.5, no cracking occurred, but 1.5 ≦ R / t <2.5 was cracked and had general bending workability (problem but practical) As indicated by “Δ”, a crack that occurred when R / t ≧ 2.5 was indicated by “x” as being inferior in bending workability (practical difficulty).
In addition, the stress corrosion cracking test was performed using a test container and a test liquid specified in JIS H3250, and an ammonia atmosphere exposure time using a liquid in which equal amounts of ammonia water and water were mixed. The stress corrosion cracking resistance was evaluated in relation to the stress relaxation rate (80% of the proof stress value of the post-processed material was applied to the surface of the post-processed material). In Tables 15 to 20 and Table 25, those having a stress relaxation rate of 20% or less after 75 hours exposure are indicated by “◎” as being excellent in corrosion cracking resistance, and the stress relaxation rate is 20% when exposed to 75 hours. Even if it exceeds 30%, it is indicated as “◯” as having good corrosion cracking resistance (no problem in practical use) when exposed for 30 hours and having a stress relaxation rate of 20% or less after 12 hours of exposure. "△" is indicated as having general corrosion cracking resistance (problem but practical), and stress relaxation cracking resistance when stress relaxation rate exceeds 20% after 12 hours exposure “X” is shown as inferior (practical).
In addition, the third invention copper alloy no. 301-No. 397, no. 302A, no. 314A, no. 338A and second comparative example alloy no. 423-No. 431 (except No. 425, No. 427, No. 431 for which production was abandoned) was subjected to a tensile test using an Amsler universal testing machine to determine the yield strength (0.2% yield strength), tensile strength and elongation. It was measured. Further, each alloy was drawn to a diameter of 3.35 mm, the drawn material (hereinafter referred to as “post-processed material”) was subjected to the same tensile test as described above, and the yield strength, tensile strength and elongation were measured, and bending work was performed. Evaluation and stress corrosion cracking test were conducted. The results were as shown in Tables 21 to 24 and Table 26. In addition, 3rd invention copper alloy No.1. 301-No. 397, no. 302A, no. 314A, no. Needless to say, the post-processed material obtained by drawing 338A is also a high-strength copper alloy according to the present invention.
The evaluation of bending workability is performed by bending the post-processed material at 90 degrees using a V block, and the degree of bending R / d when a crack occurs (R: the inner peripheral side of the bent portion) Curvature radius (mm), d: Diameter of post-processed material (mm)). In Table 18 to Table 22, what was not cracked at R / d = 0 was indicated by “◎” as being excellent in bending workability, and crack was not generated at R / d = 0.25. Those having cracks at 0 ≦ R / d <0.25 are indicated by “◯” as having good bending workability (no problem in practical use), and cracks at R / d = 0.5. Although it did not occur, a case where cracking occurred at 0.25 ≦ R / d <0.5 is indicated by “Δ” as having general bending workability (problem but practical), The case where cracking occurred at R / d = 0.5 was indicated by “x” as being inferior to bending injection (practical difficulty).
In addition, the stress corrosion cracking test is a post-processed material used for the above-described evaluation of bending workability, which is subjected to 90 ° bending with R / d = 1.5, and a tester specified in JIS H3250 and The test solution was used, exposed to ammonia using a mixture of equal amounts of ammonia water and water, and after washing with sulfuric acid, investigated for the presence of cracks with a stereo microscope 10 times, The stress corrosion cracking resistance was evaluated. In Tables 15 to 20 and Table 25, those that were not cracked after 40 hours of exposure were indicated by “◎” as being excellent in corrosion cracking resistance. Those with no corrosion cracking resistance (no problem in practical use) are marked with “○”, and those that cracked after 15 hours of exposure but without cracking after 6 hours of exposure are generally “△” indicates that it has corrosion cracking properties (problem is practical), but “x” indicates that cracking occurred after 6 hours of exposure and is inferior in stress corrosion cracking resistance (practical difficulty) It showed in.
From Tables 15 to 26, the first to third invention copper alloys achieve a finer crystal grain than the first and second comparative alloys that do not have the alloy composition and recrystallization structure specified at the beginning. It can greatly improve mechanical properties including yield strength and bending workability, and is suitable for use as a plate, strip, wire, etc. even in applications that are difficult to use with conventional high-strength copper alloys. It is understood that this is possible. It is also understood that further refinement of the crystal grains D and improvement in strength can be achieved by performing the recrystallization treatment by rapid high-temperature heat treatment. Furthermore, although not described in Tables 15 to 26, the above-described post-processed materials (recrystallized rolled materials and wiredrawing materials further cold-rolled and drawn) 150 to 600 ° C, About what heat-processed in 1 second-4 hours, it was confirmed that the spring limit value and the stress relaxation characteristic are improving significantly.

Claims (34)

4 to 19 mass% Zn and 0.5 to 2.5 mass% Si are contained so that the content of Zn-2.5 · Si = 0 to 15 mass% and the balance is made of Cu. And having an average crystal grain size D of 0.3 μm ≦ D ≦ 3.5 μm and a 0.2% proof stress in a recrystallized state of 250 N / mm ² or more. Characteristic high strength copper alloy. 0.005 to 0.5 mass% of Co is obtained by dividing the content by the Si content so that the Co / Si is 0.005 to 0.5. The high-strength copper alloy according to claim 1. The alloy composition further contains 0.03 to 1.5 mass% of Sn so that a value obtained by dividing the Si content by the content of Si / Sn is 1.5 or more. Item 2. A high-strength copper alloy according to item 1. The alloy composition further contains 0.03 to 1.5 mass% of Sn so that a value obtained by dividing the Si content by the content of Si / Sn is 1.5 or more. Item 3. A high-strength copper alloy according to item 2. A value obtained by dividing 0.005 to 0.3 mass% Fe and / or 0.005 to 0.3 mass% Ni by the total Si content (Fe + Ni) / Si is 0.005 to 0.005. The high-strength copper alloy according to claim 1, wherein the alloy composition is further contained so as to be 5. A value obtained by dividing 0.005 to 0.3 mass% Fe and / or 0.005 to 0.3 mass% Ni by the total Si content (Fe + Ni) / Si is 0.005 to 0.005. The high-strength copper alloy according to claim 3, wherein the alloy composition is further contained so as to be 5. 0.005 to 0.3 mass% Fe and / or 0.005 to 0.3 mass% Ni, and the total content of these and Co divided by the Si content (Fe + Ni + Co) / Si is 0.005 The high-strength copper alloy according to claim 2, wherein the alloy composition is further contained so as to be -0.5. 0.005 to 0.3 mass% Fe and / or 0.005 to 0.3 mass% Ni, a value obtained by dividing the total content including the case of containing Co by the Si content (Fe + Ni + Co) / Si The high-strength copper alloy according to claim 4, wherein the alloy composition further contains 0.005 to 0.5. 4 to 17 mass% Zn and 0.1 to 0.8 mass% Si are contained so that the content thereof has a relationship of Zn-2.5 · Si = 2 to 15 mass%, and the balance is made of Cu. And having an average crystal grain size D of 0.3 μm ≦ D ≦ 3.5 μm and a 0.2% proof stress in a recrystallized state of 250 N / mm ² or more. Characteristic high strength copper alloy. 0.005 to 0.5 mass% of Co, which is obtained by dividing the content by the Si content so that the Co / Si is 0.02 to 1.5. The high-strength copper alloy according to claim 9. The alloy composition further comprising 0.2 to 3 mass% of Sn so that a value obtained by dividing the Si content by the content of Si / Sn is 0.5 or less. High-strength copper alloy described in 1. The alloy composition further comprising 0.2 to 3 mass% of Sn so that a value obtained by dividing the Si content by the content of Si / Sn is 0.5 or less. High-strength copper alloy described in 1. A value obtained by dividing 0.005 to 0.3 mass% Fe and / or 0.005 to 0.3 mass% Ni by the total Si content (Fe + Ni) / Si is 0.02-1. The high-strength copper alloy according to claim 9, wherein the alloy composition is further contained so as to be 5. A value obtained by dividing 0.005 to 0.3 mass% Fe and / or 0.005 to 0.3 mass% Ni by the total Si content (Fe + Ni) / Si is 0.02-1. The high-strength copper alloy according to claim 11, wherein the alloy composition is further contained so as to be 5. 0.005 to 0.3 mass% Fe and / or 0.005 to 0.3 mass% Ni, a value obtained by dividing the total content of these and Co by the Si content (Fe + Ni + Co) / Si is 0.02 The high-strength copper alloy according to claim 10, wherein the alloy composition is further contained so as to be −1.5. 0.005 to 0.3 mass% Fe and / or 0.005 to 0.3 mass% Ni, a value obtained by dividing the total content of these and Co by the Si content (Fe + Ni + Co) / Si is 0.02 The high-strength copper alloy according to claim 12, wherein the alloy composition is further contained so as to be −1.5. An alloy composition further containing at least one element selected from 0.003 to 0.3 mass% of P, Sb, As, Sr, Mg, Y, Cr, La, Ti, Mn, Zr, In, and Hf. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11. A high-strength copper alloy according to claim 12, claim 13, claim 14, claim 15 or claim 16.
Third invention copper alloy The content of Cu-5 · Si = 62-67 mass% and Zn + 6 · Si = 32-38 mass% between 66-76 mass% Cu, 21-33 mass% Zn, and 0.5-2 mass% Si. The alloy composition is contained so as to have a relationship and the balance is made of Cu, and has a crystal structure in which the average crystal grain size D is 0.3 μm ≦ D ≦ 3.5 μm. A high-strength copper alloy having a% proof stress of 250 N / mm ² or more. 0.005 to 0.3 mass% of Co, which is obtained by dividing the content by the Si content so that the Co / Si is 0.005 to 0.4. The high-strength copper alloy according to claim 18. The alloy composition further comprising 0.03 to 1 mass% of Sn so that a value obtained by dividing the Si content by the content of Si / Sn is 1 or more. High strength copper alloy. The alloy composition further comprising 0.03 to 1 mass% of Sn so that a value obtained by dividing the Si content by the content of Si / Sn is 1 or more. High strength copper alloy. A value obtained by dividing 0.005 to 0.3 mass% Fe and / or 0.005 to 0.3 mass% Ni by the total Si content (Fe + Ni) / Si is 0.005 to 0.005. The high-strength copper alloy according to claim 18, wherein the alloy composition is further contained so as to be 4. A value obtained by dividing 0.005 to 0.3 mass% Fe and / or 0.005 to 0.3 mass% Ni by the total Si content (Fe + Ni) / Si is 0.005 to 0.005. The high-strength copper alloy according to claim 20, further comprising an alloy composition further contained so as to be 4. 0.005 to 0.3 mass% Fe and / or 0.005 to 0.3 mass% Ni, and the total content of these and Co divided by the Si content (Fe + Ni + Co) / Si is 0.005 The high-strength copper alloy according to claim 19, further comprising an alloy composition further contained so as to be −0.4. 0.005 to 0.3 mass% Fe and / or 0.005 to 0.3 mass% Ni, and the total content of these and Co divided by the Si content (Fe + Ni + Co) / Si is 0.005 The high-strength copper alloy according to claim 21, wherein the alloy composition is further contained so as to be -0.4. One selected from 0.005 to 0.2 mass% each of P, Sb and As and 0.003 to 0.3 mass% of Sr, Mg, Y, Cr, La, Ti, Mn, Zr, In and Hf, respectively When the above elements contain at least one of P, Sb, and As, the total content of these elements is 0.005 to 0.25 mass%. A high strength copper alloy according to claim 18, claim 19, claim 20, claim 21, claim 22, claim 23, claim 24 or claim 25. A recrystallized material obtained by recrystallizing a plastic working material obtained by plastic working including cold working with a working rate of 30% or more. Item 3, claim 4, claim 5, claim 6, claim 7, claim 8, claim 9, claim 10, claim 11, claim 13, claim 13, claim 15 High-strength copper according to claim 16, claim 17, claim 18, claim 19, claim 20, claim 21, claim 22, claim 23, claim 24, claim 25 or claim 26 alloy. 28. The high-strength copper alloy according to claim 27, wherein the high-strength copper alloy is a recrystallized material that is recrystallized by heat-treating a plastic working material at 450 to 750 [deg.] C. for 1 to 1000 seconds. The high-strength copper alloy according to claim 27, wherein the high-strength copper alloy is a cold-worked material obtained by cold-rolling or cold-drawing a recrystallized material. 30. The high-strength copper alloy according to claim 29, wherein the cold-worked material is heat-treated under conditions of 150 to 600 and 1 second to 4 hours. 30. The high-strength copper alloy according to claim 29, which is a product processed material obtained by processing a cold processed material into a predetermined product shape. The high-strength copper alloy according to claim 31, wherein the product processed material is heat-treated under conditions of 150 to 600, 1 second to 4 hours. It is a rolled material or a product processed material obtained by processing this into a predetermined product shape. Claims 1, 2, 3, 4, 5, 6, and 7 A high-strength copper alloy according to claim 8, claim 9, claim 10, claim 11, claim 12, claim 13, claim 15, claim 16, or claim 17. A wire-drawn material or a product-processed material obtained by processing the wire-drawn material into a predetermined product shape. 27. A high strength copper alloy according to claim 25 or claim 26.