WO2023167230A1

WO2023167230A1 - Copper alloy material and method for manufacturing copper alloy material

Info

Publication number: WO2023167230A1
Application number: PCT/JP2023/007544
Authority: WO
Inventors: 佳紀山本; 達也外木; 健二児玉
Original assignee: 株式会社プロテリアル
Priority date: 2022-03-04
Filing date: 2023-03-01
Publication date: 2023-09-07
Also published as: JP7537643B2; JPWO2023167230A1; KR20240121247A; CN118434892A

Abstract

Provided are: a copper alloy material that does not have problems with residual smut, similar to C1940 and other Cu–Fe–Zn–P copper alloy materials, that has tensile strength and conductivity roughly comparable to those of C7025 and other Cu–Ni–Si copper alloy materials, and that preferably has good bending workability; and a method for manufacturing the copper alloy material. A copper alloy casting material is obtained by adding iron, phosphorous, zinc, and tin and performing melt casting. The manufacturing method proceeds through: hot rolling; cold rolling; heat treatment under sustained conditions of 500–600°C for up to four hours; cold rolling at 20–90% draft; heat treatment under sustained conditions of 380–480°C for one to twelve hours; cold rolling at 60–80% draft; and heat treatment under sustained conditions of 250–380°C for up to four hours. By said method, obtained is a copper alloy material that contains, by mass percentage, 1.6–2.6% iron, 0.01–0.35% phosphorus, 0.01–0.30% zinc, and 0.3–0.8% tin, the remainder consisting of copper and impurity elements, that has tensile strength of at least 620 MPa, and that has conductivity of at least 40.0% IACS.

Description

COPPER ALLOY MATERIAL AND METHOD FOR MANUFACTURING COPPER ALLOY MATERIAL

The present invention relates to a copper alloy material and a method for producing a copper alloy material, and for example, to a copper alloy material and a method for producing a copper alloy material used as materials for electrical and electronic parts such as lead frames, connectors, and terminals.

Conventionally, copper alloys have good strength and conductivity, so they are commonly used as materials for electrical and electronic parts such as lead frames. Among copper alloys, for example, a Cu--Fe--Zn--P-based copper alloy is said to have a good balance of mechanical strength, electrical conductivity, and thermal conductivity. One of the typical Cu—Fe—Zn—P-based copper alloys is, for example, C1940 defined in JIS-H3100:2018. C1940 is a precipitation hardening copper alloy containing, by mass, about 2.2% Fe, about 0.03% P, and about 0.12% Zn. C1940 has an electrical conductivity of about 60% IACS and a tensile strength of about 400 MPa to 550 MPa, and is internationally recognized as a standard copper alloy and used in many applications.

In recent years, in the field of lead frames, for example, lead frames themselves are becoming thinner as electrical and electronic components become more sophisticated and highly integrated. A thin lead frame is easily deformed, and the above C1940 is insufficient in mechanical strength. In such cases, for example, a Cu--Ni--Si based copper alloy is often used. A Cu—Ni—Si-based copper alloy is a precipitation-hardening copper alloy that obtains high strength by precipitating particles of a compound containing Ni and Si in a Cu-based parent phase of the copper alloy. One of the representative copper alloys of the Cu—Ni—Si system is, for example, C7025 called Corson alloy. C7025 is a copper alloy containing about 3.0% Ni, about 0.65% Si, and about 0.15% Mg, in terms of percentages by mass, although it is not specified in the above JIS. . C7025 has a tensile strength of about 600 MPa to 700 MPa and an electrical conductivity of about 45.0% IACS, and although it is inferior to C1940 in bending workability, it is also used for the lead frame described above.

Japanese Patent No. 6301618 Japanese Patent No. 6811136

In the electric and electronic parts including the lead frame described above, a solder plating layer or a silver plating layer is provided on the surface of the copper alloy material made of copper alloy for the purpose of facilitating mounting of the silicon chip and mounting on the wiring board. that is commonly done. When providing a plated layer on the surface of a copper alloy material, chemical polishing is generally performed as a pretreatment for chemically dissolving an oxidized layer or a work-affected layer on the surface with an acid solution. For example, in the case of a copper alloy material made of a Cu--Fe--Zn--P based copper alloy such as C1940, chemical polishing with an acidic liquid (chemical polishing liquid) containing sulfuric acid and hydrogen peroxide is common. A copper alloy material made of a Cu--Fe--Zn--P based copper alloy such as C1940 does not have the problem of smut remaining on the surface of the copper alloy material (hereinafter referred to as residual smut), which will be described later.

However, in the case of a copper alloy material made of a higher-strength copper alloy, for example, a copper alloy material made of a Cu—Ni—Si-based copper alloy such as C7025, Ni and Si are removed when a chemical polishing liquid of the same quality as C1940 is used. Particles of compound containing are not dissolved. Therefore, the particles of the compound containing Ni and Si become residue (smut) and remain on the surface of the copper alloy material in large quantities. Residual smut on the surface of copper alloy materials is not easily removed by general surface cleaning after chemical polishing. Therefore, smut may be mixed in the plated layer provided thereafter, which may greatly affect the appearance and characteristics of the copper alloy material.

To solve the problem of residual smut on the surface of higher-strength copper alloy materials such as C7025, for example, Patent Document 1 discloses controlling the particle size and shape of a compound containing Ni and Si to improve the surface of the copper alloy material. We propose a method to reduce the residual area ratio of residual smut to less than 3%, and the content percentages expressed in mass% are Ni: 2.0 to 6.0%, Si: 0.3 to 2.0%, and Cr: 0. Disclosed is a copper alloy material containing ~1.0%, Mg: 0-1.0%, Sn: 0-0.8% and Zn: 0-0.8%, the balance being Cu and impurities. In addition, Patent Document 2 proposes a method for improving adhesion with resin by leaving unevenness on the surface of the copper alloy material by adjusting the amount of residual smut on the surface of the copper alloy material. At a rate, Ni: 1.5 to 4.5%, Si: 0.4 to 1.1%, the balance is Cu and impurities, and has a tensile strength of 800 MPa or more and an electrical conductivity of 30% IACS or more. A Cu--Ni--Si based copper alloy strip is disclosed. However, both the proposals of Patent Documents 1 and 2 allow residual smut on the surface of the copper alloy material, and do not fundamentally solve the problem of residual smut occurring on the surface of the copper alloy material.

Therefore, according to the present invention, there is no problem of residual smut as with copper alloy materials made of Cu-Fe-Zn-P-based copper alloys such as C1940, and higher strength Cu-Ni-Si-based materials such as C7025 Provided are a copper alloy material having approximately the same tensile strength and electrical conductivity as those of the copper alloy material of (1) and desirably good bending workability, and a method for producing the copper alloy material. In addition, copper alloy materials containing a large amount of additive elements such as those described above (for example, Ni, Si, Cr, Mg, Sn, Zn, etc.) generally have poor rolling workability, and cracks occur particularly at the stage of hot rolling. It's easy to do. Therefore, the present invention desirably provides a copper alloy material and a method for producing a copper alloy material that are excellent in rolling workability, particularly resistant to cracking during hot rolling.

The inventor has developed a copper alloy material composed of a Cu--Fe--Zn--P-based copper alloy having no problem of residual smut, and a copper alloy material composed of a Cu--Ni--Si-based copper alloy having a problem of residual smut. We investigated the morphology and properties of the structure, mechanical and electrical properties, manufacturing conditions, etc. from various aspects. As a result, the above problem was solved by further devising the alloy composition of the Cu-Fe-Zn-P-based copper alloy and further devising the manufacturing conditions of the copper alloy material made of the copper alloy. I found that it can be done, and came up with this invention.

That is, the copper alloy material according to the present invention contains 1.6% or more and 2.6% or less of Fe and 0.01% or more and 0.3% or less of P and 0.01% or more and 0.3% or less of Zn, 0.3% or more and 0.8% or less of Sn, the balance being Cu and impurity elements, in a temperature environment of 20 ° C., A copper alloy material having a tensile strength of 620 MPa or more and an electrical conductivity of 40.0% IACS or more.

The copper alloy material according to the present invention is preferably a copper alloy material containing 0.01% or more and 0.20% or less of P in terms of mass % content.

In the copper alloy material according to the present invention, the content in mass % is, as essential elements, Fe, P, Zn, and Sn, and Mn of 0.002% or more and 0.025% or less. with the balance being Cu and impurity elements, and having a breaking elongation of more than 20% in a temperature environment of 950°C.

In the copper alloy material according to the present invention, the content in mass % is (Mn content + total impurity element content) / (Fe content + P content + Sn content) x 100. 1 or less, preferably a copper alloy material.

In addition, in the method for producing a copper alloy material according to the present invention, the content in mass% is 1.6% or more and 2.6% or less of Fe and 0.01% or more and 0.3% as essential elements. A copper alloy casting material containing the following P, 0.01% or more and 0.3% or less of Zn, 0.3% or more and 0.8% or less of Sn, and the balance being Cu and impurity elements A melting and casting process for producing, a hot rolling process for producing a hot rolled material by performing hot rolling using the copper alloy cast material, and a cold rolling process using the hot rolled material to perform the first A first cold-rolling step of producing a cold-rolled material, and a first heat-treated material is produced by heating and holding the first cold-rolled material at a temperature of 500 ° C. or higher and 600 ° C. or lower for 4 hours or less. 1 heat treatment step, a second cold rolling step of cold rolling at a rolling reduction rate of 20% or more and 90% or less using the first heat treated material to produce a second cold rolled material, A second heat treatment step of producing a second heat treated material by heating and holding the cold rolled material at a temperature of 380 ° C. or higher and 480 ° C. or lower for 1 hour or more and 12 hours or less, and 60% or more using the second heat treated material. A third cold rolling step of cold rolling at a rolling reduction rate of 80% or less to produce a third cold rolled material, and subjecting the third cold rolled material to a temperature of 250 ° C. or higher and 380 ° C. or higher. a third heat treatment step of producing a copper alloy material by heating and holding for 4 hours or less, wherein the melting and casting step, the hot rolling step, the first cold rolling step, the first heat treatment step, the By performing the second cold rolling step, the second heat treatment step, the third cold rolling step, and the third heat treatment step in this order, a tensile strength of 620 MPa or more is obtained in a temperature environment of 20 ° C. and having an electrical conductivity of 40.0% IACS or higher.

A method for producing a copper alloy material according to the present invention is a method for producing a copper alloy material containing 0.01% or more and 0.20% or less of P in terms of mass% content. Preferably.

In the method for producing a copper alloy material according to the present invention, the content in mass % is, as the essential elements, Fe, P, Zn, and Sn, and 0.002% or more and 0.025% or less A melting and casting step for producing a copper alloy casting material containing Mn and the balance consisting of Cu and impurity elements, followed by the hot rolling step, the first cold rolling step, and the first heat treatment step , the second cold rolling step, the second heat treatment step, the third cold rolling step, and the third heat treatment step in this order,
It is preferable that the method for producing a copper alloy material produces a copper alloy material having a breaking elongation of more than 20% in a temperature environment of 950°C.

In the method for producing a copper alloy material according to the present invention, the content in mass% is (Mn content + total impurity element content) / (Fe content + P content + Sn content) x 100. , 1.1 or less.

According to the present invention, there is no problem of residual smut as with a copper alloy material made of a Cu-Fe-Zn-P-based copper alloy such as C1940, and a higher strength Cu-Ni-Si-based material such as C7025 It is possible to provide a copper alloy material and a method for producing a copper alloy material that have substantially the same tensile strength and electrical conductivity as a copper alloy material made of a copper alloy of. In addition, according to the present invention, by appropriately selecting the configuration, a copper alloy material with good bending workability and a method for producing a copper alloy material, A method for manufacturing an alloy material and a copper alloy material can be provided.

1 is a diagram showing a flow of main steps in a method of manufacturing a copper alloy material according to the present invention; FIG.

The structure of the copper alloy material according to the present invention will be described below, and then the method for manufacturing the copper alloy material will be described along the flow of the main steps shown in FIG. It should be noted that the copper alloy material and the method for producing the copper alloy material according to the present invention are indicated by the scope of claims, and can be understood to include all modifications within the meaning and scope of equivalents of the scope of the claims. Considerable. The contents (numerical values) of elements and the chemical components (numerical values) of materials are expressed in % by mass unless otherwise specified.

The copper alloy material according to the present invention contains, as essential elements, Fe (iron) of 1.6% or more and 2.6% or less, P (phosphorus) of 0.01% or more and 0.3% or less, and 0.5% or more. Contains 01% or more and 0.3% or less of Zn (zinc) and 0.3% or more and 0.8% or less of Sn (tin) (preferably more than 0.3% and 0.8% or less) The balance consists of Cu (copper) and impurity elements, and has a tensile strength of 620 MPa or more (preferably 625 MPa or more, more preferably 630 MPa or more) in a temperature environment of 20 ° C. and 40.0% IACS or more. (preferably 45.0% IACS or higher). The copper alloy constituting the copper alloy material according to the present invention is a Cu--Fe--P--Zn--Sn based copper alloy from the viewpoint of alloy composition.

The copper alloy material according to the present invention preferably contains 0.01% or more and 0.20% or less of P.

The copper alloy material according to the present invention preferably contains Fe (1.6% or more and 2.6% or less) and P (0.01% or more and 0.3% or less, preferably 0 .01% or more and 0.20% or less), the Zn (0.01% or more and 0.3% or less), and the Sn (0.3% or more and 0.8% or less, preferably more than 0.3% 0.8% or less), and furthermore, 0.002% or more and 0.025% or less of Mn, the balance being Cu and impurity elements, and breaking more than 20% in a temperature environment of 950 ° C. have elongation.

The copper alloy material according to the present invention preferably has a value obtained by (Mn content + total content of impurity elements)/(Fe content + P content + Sn content) x 100 (hereinafter referred to as "MI value"). ) is less than or equal to 1.1.

The reasons for limiting the elements contained in the copper alloy constituting the copper alloy material according to the present invention are as follows.

<Fe (iron)>
The copper alloy material according to the present invention contains 1.6% or more and 2.6% or less of Fe as an essential element. In the copper alloy material, Fe dissolves in a matrix mainly composed of Cu of the copper alloy. A part of Fe is dispersed and precipitated in the matrix phase as a compound containing Fe or Fe and P. Such action of Fe contributes to the improvement of the mechanical strength and heat resistance of the copper alloy material. Therefore, a copper alloy material containing an appropriate amount of Fe can have higher mechanical strength and heat resistance while reasonably maintaining electrical conductivity.

If the amount of Fe contained in the copper alloy material is excessively low (less than 1.6%), the effects of Fe described above are not sufficiently exhibited. In addition, when the amount of Fe contained in the copper alloy material is excessively large (exceeding 2.6%), excessive Fe crystallized substances are formed in the copper alloy cast material described later, which causes deterioration of surface cleanliness and work cracks. can be From this point of view, the copper alloy material according to the present invention contains 1.6% or more and 2.6% or less of Fe, preferably 2.1% or more and 2.4% or less in order to obtain more well-balanced characteristics. do. In addition, the copper alloy material according to the present invention contains 1.6% or more and 2.6% or less of Fe (preferably 2.1% or more and 2.4% or less), and the Sn content is considered as described later. A good balance between tensile strength and electrical conductivity is obtained. In this case, for example, the copper alloy material has a tensile strength of 630 MPa or more and an electrical conductivity of 45.0% IACS or more.

<P (Phosphorus)>
The copper alloy material according to the present invention contains 0.01% or more and 0.3% or less of P as an essential element. In the copper alloy material, P acts as a deoxidizing agent that removes excess oxygen present in the molten metal (molten metal) in the melting and casting process, which will be described later. In addition, a part of P forms a compound containing Fe and P, and is dispersed and precipitated in the matrix phase mainly composed of Cu of the copper alloy. Such action of P contributes to the improvement of the mechanical strength and heat resistance of the copper alloy material. Therefore, a copper alloy material containing an appropriate amount of P can have higher mechanical strength and heat resistance while maintaining the electrical conductivity accordingly.

It should be noted that if the amount of P contained in the copper alloy material is excessively low (less than 0.01%), the action and effect of P described above cannot be sufficiently exhibited. In addition, when the P content in the copper alloy material is excessively large (exceeding 0.3%), it may cause a decrease in hot workability in the hot rolling process described later and a decrease in the electrical conductivity of the copper alloy material. There is From this point of view, the copper alloy material according to the present invention has a P content of 0.01% or more and 0.3% or less, more preferably 0.01% or more and 0.20% or less for improving bending workability. .

<Zn (zinc)>
The copper alloy material according to the present invention contains 0.01% or more and 0.3% or less of Zn as an essential element. In the copper alloy material, Zn improves the wettability of the surface of the copper alloy material to solder and improves the weather resistance of the solder-plated layer provided on the surface of the copper alloy material. Such an effect of Zn is particularly required when a solder plating layer is provided on the surface of a copper alloy material such as the lead frame described above. Therefore, a copper alloy material containing an appropriate amount of Zn has high practical applicability.

If the copper alloy material contains too little Zn (less than 0.01%), the above effects of Zn cannot be sufficiently exhibited. Moreover, when the Zn content in the copper alloy material is excessively large (exceeding 0.3%), the effects of Zn described above are saturated, and this may cause a decrease in electrical conductivity of the copper alloy material. From this point of view, the copper alloy material according to the present invention contains 0.01% or more and 0.3% or less of Zn, preferably 0.05% or more and 0.2% or less in order to obtain more well-balanced properties. do.

<Sn (tin)>
The copper alloy material according to the present invention contains 0.3% or more and 0.8% or less (preferably, more than 0.3% and 0.8% or less) of Sn as an essential element. In a copper alloy material, Sn forms a solid solution in the parent phase of the copper alloy, which is mainly composed of Cu, and contributes to further improvement of the mechanical strength and heat resistance of the copper alloy material. Therefore, a copper alloy material containing an appropriate amount of Sn can have higher mechanical strength and heat resistance while maintaining a corresponding amount of electrical conductivity, compared to a copper alloy material that does not contain an appropriate amount of Sn. Using the action of Sn, the mechanical strength of a copper alloy material made of a Cu-Fe-Zn-P-based copper alloy is brought to a level substantially equivalent to that of a copper alloy material made of a Cu-Ni-Si-based copper alloy. can be lifted. In addition, this Sn is not added to C1940 and C7025 described above. Further, even if a copper alloy material made of a Cu--Fe--Zn--P system copper alloy further contains an appropriate amount of Sn, the problem of residual smut does not occur. For this point, refer to Table 1, etc., which will be described later.

It should be noted that if the amount of Sn contained in the copper alloy material is excessively low (less than 0.3%), the effects of Sn cannot be sufficiently exhibited. In addition, when the amount of Sn contained in the copper alloy material is excessively large (exceeding 0.8%), the mechanical strength of the copper alloy material is further improved, but the electrical conductivity of the copper alloy material is greatly reduced. . From this point of view, the copper alloy material according to the present invention has a Sn content of 0.3% or more and 0.8% or less, preferably more than 0.3% and 0 in order to stably obtain a tensile strength of 625 MPa or more. .8% or less. For this point, refer also to the section on the effect of Sn, which will be described later. Further, the copper alloy material according to the present invention has a preferable balance between tensile strength and electrical conductivity when the Sn content is 0.5% or more and 0.7% or less and the Fe content is considered as described above. In this case, for example, the copper alloy material has a tensile strength of 630 MPa or more and an electrical conductivity of 45.0% IACS or more.

<Mn (manganese)>
The copper alloy material according to the present invention contains, as essential elements, Fe, P, Zn, and Sn within the above ranges, and preferably 0.002% or more and 0.025% or less of Mn. The copper alloy material according to the present invention is, as described above, a copper alloy material made of a Cu--Fe--P--Zn--Sn based copper alloy. While Fe and P contained in this copper alloy material are essential elements, they are also elements that cause work cracks and deterioration of hot workability as described above. In addition, this copper alloy material may contain S (sulfur), which is an impurity element, derived from a generally used manufacturing raw material (copper material). Due to the solid solution of S, the copper alloy material has poor rolling workability, and cracks are likely to occur particularly at the stage of hot rolling. . Therefore, the copper alloy material preferably further contains Mn as an essential element to actively generate MnS, thereby reducing the amount of S that forms a solid solution.

Practically, the S content in the raw material for general production of this copper alloy material can be considered to be about 0.001% to 0.005%. The composition ratio (Mn:S) of MnS is 1:1 in atomic ratio and 63:37 in mass ratio. Therefore, assuming that the entire amount of S reacts with Mn, about 1.7 times as much Mn as S is required in mass ratio. For example, a copper alloy material containing 0.001% or more and 0.005% or less of S in mass % needs to contain 0.0017% or more and 0.0085% or less of Mn in terms of calculation. However, not all of the Mn actually reacts with S to form MnS. Therefore, it is practical to set the amount of Mn sufficiently large relative to the amount of S, and to contain Mn two to five times the amount of S (mass ratio). From this point of view, in the copper alloy material according to the present invention, when the S content is expected to be 0.001% or more and 0.005% or less, it is preferable that Mn is 0.002% or more and 0.002% or more in correspondence with the S amount. Set within a range of 0.025% or less. Moreover, if S is 0.002% or less, Mn is preferably set in the range of 0.010% or less corresponding to the amount of S. As a result, the copper alloy material has good rolling workability and is particularly resistant to cracking during hot rolling.

<Cu (copper)>
The copper alloy material according to the present invention is composed of Cu and impurity elements except for Fe, P, Zn, and Sn, which are the above-described essential elements. When Mn is further included, the copper alloy material according to the present invention consists of Cu and impurity elements except for Fe, P, Zn, Sn, and Mn, which are the above-described essential elements. In this copper alloy material, Cu is contained in a range of approximately 96% or more and 98% or less according to the content of the essential elements described above. In this copper alloy material, the remainder excluding Cu and the above-described essential elements is impurity elements. In a copper alloy material, Cu (copper) is the main element that constitutes the parent phase of the copper alloy, and is contained in the largest amount. Copper materials made of copper and copper alloy materials made of copper alloys have excellent electrical conductivity and are widely used as materials for electrical and electronic parts. For example, a copper material made of oxygen-free copper such as C1020 or C1100 standardized by JIS has a conductivity of about 100% IACS and a tensile strength of about 195 MPa (temper O) to 315 MPa (temper H). A copper alloy material made of C1940 has an electrical conductivity of 60% IACS or more and less than 100% IACS and a tensile strength of about 275 MPa (O3 temper) to 590 MPa (ESH temper). A copper alloy material made of C7025 has an electrical conductivity of about 45.0% IACS and a tensile strength of about 650 MPa (temper classification 1/2·H).

<Impurity element>
The copper alloy material according to the present invention contains impurity elements. This impurity element is inevitably mixed in during the manufacturing process of the copper alloy material and is not intentionally added. The impurity elements depend on the manufacturing raw materials and manufacturing equipment used, but include elements such as Ag (silver), Pb (lead), Ni (nickel) and S (sulfur). If these impurity elements are excessively mixed, there is a risk of deteriorating various properties (tensile strength, electrical conductivity, bending workability, etc.) of the copper alloy material. In addition, in this copper alloy material, as described above, S in a solid solution state causes deterioration of rolling workability, particularly cracking at the stage of hot rolling. From this point of view, the content of impurity elements in the copper alloy material is suppressed as low as possible, for example, the total is suppressed to 0.05% or less, preferably 0.03% or less, more preferably 0.01% or less. .

In addition, in the copper alloy material according to the present invention, as described above, Fe and P are related to work cracking and deterioration of hot workability. Further, Sn relates to mechanical strength and heat resistance. In addition, impurity elements such as Ag, Pb, Ni and S are related to deterioration of tensile strength and bending workability. Further, when Mn is further contained, the relationship between Mn and S relates to deterioration of rolling workability and cracking at the stage of hot rolling. Considering the effects of impurity elements such as Fe, P, Sn, Mn and S, the copper alloy material according to the present invention preferably contains Mn. In that case, preferably, the value obtained by (Mn content + total content of impurity elements)/(Fe content + P content + Sn content) x 100 (hereinafter referred to as "MI value") is considered. , the MI value is, for example, 1.1 or less (>0), preferably 1.0 or less (>0), thereby improving the rolling workability (especially hot workability) of the copper alloy material according to the present invention. ) can be sufficiently enhanced.

The copper alloy material according to the present invention contains Fe, P, Zn, and Sn as essential elements within the ranges described above, with the balance being Cu and impurity elements. As a result, this copper alloy material has a tensile strength of 620 MPa or more (preferably 625 MPa or more, more preferably 630 MPa or more) and 40.0% IACS or more (preferably 45.0 MPa or more) in a temperature environment of 20°C. It has a conductivity of 0% IACS or more), and the generation of residual smut is suppressed as described later. This copper alloy material has the above-described tensile strength and conductivity, and since the generation of residual smut is suppressed, it is practically a copper alloy material made of a Cu-Fe-Zn-P-based copper alloy such as C1940. It is considered that it can be sufficiently used as a substitute material for a copper alloy material composed of C7025, which has a higher strength.

In addition, the copper alloy material according to the present invention contains Fe, P, Zn, Sn, and Mn as essential elements within the ranges described above, with the balance being Cu and impurity elements. As a result, the copper alloy material has an elongation at break of more than 20% in a temperature environment of 950° C., improves rolling workability, and is particularly resistant to cracking during hot rolling. This copper alloy material has the above-mentioned tensile strength, electrical conductivity and elongation at break, and since the generation of residual smut is suppressed, it is practically made of a Cu-Fe-Zn-P-based copper alloy such as C1940. It is considered that it can be sufficiently used as a copper alloy material or a substitute material for a copper alloy material composed of C7025, which has a higher strength.

The tensile strength of the copper alloy material according to the present invention mainly depends on precipitation strengthening due to dispersed precipitation of particles of Fe or a compound containing Fe and P and work hardening due to cold rolling. The strengthening mechanism of the copper alloy structure by precipitation strengthening and work hardening can be controlled by specifying the manufacturing conditions. The effect of precipitation strengthening can be obtained by controlling the holding conditions of the heat treatment within a specific range and uniformly dispersing and precipitating particles of an appropriate size that can act as obstacles to the deformation of the copper alloy structure. The effect of work hardening can be obtained by controlling the working conditions of cold rolling within a specific range and by appropriately accumulating crystals containing dislocations that can act as obstacles to deformation of the copper alloy structure. In addition, although the electrical conductivity of the copper alloy material according to the present invention substantially depends on Cu, it also utilizes the action of increasing the purity of Cu in the parent phase due to the precipitation of the particles described above.

A copper alloy material made of a Cu-Fe-P-Zn-Sn-based copper alloy has a tensile strength of 620 MPa or more (preferably 625 MPa or more, more preferably 630 MPa or more) in a temperature environment of 20 ° C., The manufacturing method is important in order to have a conductivity of 40.0% IACS or more (preferably 45.0% IACS or more). That is, the method for producing a copper alloy material according to the present invention has the following steps (1) to (8), and the steps (1) to (8) are carried out in this order.

(1) Fe of 1.6% or more and 2.6% or less and P of 0.01% or more and 0.3% or less (preferably 0.01% or more and 0.20% or less) as essential elements to be contained , containing 0.01% or more and 0.3% or less of Zn, 0.3% or more and 0.8% or less of Sn, and the balance being Cu and impurity elements, melting and casting for producing a copper alloy casting material Step (2) Hot-rolling step of hot-rolling the copper alloy cast material to produce a hot-rolled material (3) Cold-rolling the hot-rolled material to produce the first cold-rolled material First cold-rolling step (4) for producing the first cold-rolled material The first heat-treatment step ( 5) Second cold-rolling step of cold-rolling the first heat-treated material at a rolling reduction rate of 20% or more and 90% or less to produce a second cold-rolled material (6) Second cold-rolled material Second heat treatment step of producing a second heat treated material by heating and holding at a temperature of 380 ° C. to 480 ° C. for 1 h to 12 h (7) Using the second heat treated material Third cold-rolling step of cold-rolling at a rolling reduction to produce a third cold-rolled material (8) Heating the third cold-rolled material at a temperature of 250° C. or higher and 380° C. or higher for 4 hours or less A third heat treatment step of holding and producing a copper alloy material

According to the production method having the main process flow of (1) to (8) described above, Fe of 1.6% or more and 2.6% or less and 0.01% or more and 0.3% or less (preferably, 0.01% or more and 0.20% or less) of P, 0.01% or more and 0.3% or less of Zn, and 0.3% or more and 0.8% or less of Sn, and the balance is Cu and A copper alloy material containing impurity elements and having a tensile strength of 620 MPa or more and an electrical conductivity of 40.0% IACS or more in a temperature environment of 20° C. can be produced.

Further, in the step (1) described above, preferably, as essential elements to be contained, Fe, P, Zn, and Sn, and 0.002% or more and 0.025% or less of Mn are contained, and the balance is Cu. and an impurity element to produce a copper alloy casting material. In this case, in the step (1) described above, the copper alloy cast material is prepared to have an MI value of, for example, 1.1 or less (>0), preferably 1.0 or less (>0). After that, the steps (2) to (8) described above are performed in this order. According to this manufacturing method, Fe, P, Zn, and Sn are contained within the ranges described above, and further, 0.002% or more and 0.025% or less of Mn is contained, and the balance is Cu and impurity elements. A preferred copper alloy material can be produced. This preferred copper alloy material has a tensile strength of 620 MPa or more and an electrical conductivity of 40.0% IACS or more in the temperature environment of 20° C., and further, in a temperature environment of 950° C., It can have an elongation at break greater than 20%.

A method for manufacturing a copper alloy material according to the present invention will be described below along the main process flow shown in FIG. In the method for producing a copper alloy material according to the present invention, in the flow of the main steps shown in FIG. 1, the first cold rolling step and the first heat treatment step may be combined and repeated as necessary. It is also possible to combine and repeat the first heat treatment step and the second cold rolling step.

(1) Melting and casting process In the melting and casting process, a copper alloy cast material to which Fe, P, Zn and Sn are added is produced. Specifically, the copper alloy material obtained through the third heat treatment step is, in mass%, 1.6% or more and 2.6% or less of Fe, 0.01% or more and 0.3% or less of P, It contains 0.01% or more and 0.3% or less of Zn and 0.3% or more and 0.8% or less of Sn (preferably more than 0.3% and 0.8% or less), and the balance is A copper alloy casting material is produced by preparing a material containing Cu and impurity elements. Incidentally, the S content of the raw material for general production of this copper alloy material is, for example, about 0.001% to 0.005%. Therefore, in order to suppress or mitigate the influence of S, the copper alloy material preferably further contains Mn. In that case, the Mn content is adjusted to 0.002% or more and 0.025% or less, and preferably the MI value is also adjusted. The MI value is adjusted to, for example, 1.1 or less (>0), preferably 1.0 or less (>0).

(2) Hot Rolling Step In the hot rolling step, the copper alloy cast material produced in the melting and casting process is hot rolled to produce a hot rolled material. The hot rolling conditions such as the heat holding temperature and the degree of rolling workability may be arbitrarily selected from general conditions. Generally, in the case of copper materials and copper alloy materials, hot rolling is performed at a wide temperature range of 700° C. to 1000° C. depending on the composition. In the case of a copper alloy material with a relatively large total content of additive elements, hot rolling is performed at a higher temperature of 900°C to 1000°C. From this point of view, the high-temperature characteristics of the copper alloy material according to the present invention are evaluated at a temperature near the center of 900° C. to 1000° C. (approximately 950° C.).

(3) First Cold Rolling Step In the first cold rolling step, the hot rolled material produced in the hot rolling step is cold rolled to produce the first cold rolled material. Cold rolling conditions such as the degree of rolling workability may be arbitrary.

(4) First heat treatment step In the first heat treatment step, the first cold-rolled material produced in the first cold rolling step is heated and held at a temperature of 500°C or higher and 600°C or lower for 4 hours or less. to produce a first heat-treated material. This first heat treatment step is a heat treatment that is performed after the first cold rolling, which is the first rolling, and is a heat treatment that is performed to sufficiently release the strain accumulated in the copper alloy structure during the cold rolling. In the conventional general copper alloy material manufacturing method, the heat treatment at this stage is performed by heating and holding at a relatively high temperature (for example, 700° C. or more and 900° C. or less). On the other hand, in the first heat treatment step of the present invention, heating and holding is performed at a relatively low temperature of 500° C. or more and 600° C. or less for 4 hours or less. By heating and holding at a relatively low temperature, not only the effect of moderately releasing strain in the copper alloy structure but also the effect of appropriately precipitating particles of Fe or a compound containing Fe and P in the copper alloy structure can be obtained. The particles appropriately dispersed and precipitated in the copper alloy structure at this stage act to further improve the tensile strength of the finally obtained copper alloy material.

If the heating and holding temperature in the first heat treatment step is excessively low (less than 500° C.), not only will the release of strain in the copper alloy structure be insufficient, but precipitation of the above particles into the copper alloy structure will be inadequate. be enough. Further, when the heating and holding temperature in the first heat treatment step is excessively high (exceeding 600 ° C.) or the heating and holding time is excessively long (exceeding 4 hours), the strain of the copper alloy structure is sufficiently released, The particles precipitated in the copper alloy structure may be excessively coarsened and hinder the improvement of the tensile strength of the copper alloy material. In addition, when the heating and holding temperature in the first heat treatment step is the above-described relatively high temperature (for example, 700° C. or higher and 900° C. or lower), there is a possibility that the particles may not be precipitated. From this point of view, in the first heat treatment step, the first cold-rolled material is heated and held at a temperature of 500 ° C. or higher and 600 ° C. or lower for 4 hours or less, preferably to release strain and precipitate the particles. In order to obtain a well-balanced copper alloy structure, heating and holding should be performed at a temperature of 550° C. or higher and 600° C. or lower for 4 hours or less (preferably 2 hours or less).

(5) Second cold rolling step In the second cold rolling step, the first heat treated material produced in the first heat treatment step is used to perform cold rolling at a rolling reduction rate of 20% or more and 90% or less. to produce a second cold rolled material. This second cold rolling step is a step of introducing and appropriately accumulating dislocations in the copper alloy structure of the first heat-treated material produced in the first heat treatment step, and moderately work hardening the copper alloy structure. The dislocations introduced into the crystals forming the copper alloy structure act as starting points for precipitating particles responsible for precipitation strengthening of the copper alloy structure. Therefore, by uniformly introducing dislocations into the copper alloy structure at this stage and accumulating them appropriately, the particles responsible for precipitation strengthening of the copper alloy structure are evenly distributed in the copper alloy structure in the next second heat treatment step. can be precipitated. As a result, the tensile strength of the finally obtained copper alloy material can be further improved.

If the degree of rolling reduction in the second cold rolling step is excessively small (less than 20%), introduction and accumulation of dislocations into the copper alloy structure will be insufficient, and in the following second heat treatment step, The number of particles deposited on the surface tends to be insufficient. In addition, if the degree of rolling reduction in the second cold rolling step is excessively large (more than 90%), the particles precipitated in the copper alloy structure in the following second heat treatment step grow excessively large, resulting in the effect of precipitation strengthening. is difficult to obtain. From this point of view, in the second cold rolling step, the first heat-treated material produced in the first heat treatment step is cold-rolled at a rolling reduction rate of 20% or more and 90% or less. In order to finally obtain a synergistic effect of precipitation strengthening and work hardening in a well-balanced manner, cold rolling is performed at a rolling workability of 40% or more and 75% or less.

(6) Second heat treatment step In the second heat treatment step, the second cold-rolled material produced in the second cold rolling step is heated and held at a temperature of 380 ° C. or higher and 480 ° C. or lower for 1 hour or more and 12 hours or less. to produce a second heat-treated material. This second heat treatment step is a heat treatment performed after the second cold rolling described above, and utilizes dislocations introduced and accumulated during cold rolling to sufficiently disperse particles responsible for precipitation strengthening in the copper alloy structure. This is the step of aging treatment for precipitation. In the case of a conventional method for producing a copper alloy material composed of a general Cu--Fe--P-based copper alloy, heating and holding for aging treatment is performed at a temperature of, for example, 400.degree. C. or higher and 600.degree. On the other hand, in the second heat treatment step of the present invention, heating and holding is performed for 1 hour or more and 12 hours or less at a temperature of 380° C. or more and 480° C. or less, which is on the relatively low temperature side. By heating and holding at the relatively low temperature side, particles of Fe or a compound containing Fe and P precipitated in the copper alloy structure can be made finer and dispersed more uniformly. As a result, the effect of precipitation strengthening on the copper alloy structure can be sufficiently obtained. In addition, by intentionally making the release of strain in the copper alloy structure insufficient by heating and holding at this relatively low temperature side, the synergistic effect of precipitation strengthening and work hardening obtained by the second cold rolling process can be obtained sufficiently.

If the heating and holding temperature in the second heat treatment step is excessively low (less than 380°C) or the heating and holding time is excessively short (less than 1 hour), the precipitation of the particles into the copper alloy structure is insufficient. resulting in insufficient tensile strength and electrical conductivity of the finally obtained copper alloy material. Further, when the heating and holding temperature in the second heat treatment step is excessively high (over 480°C) or the heating and holding time is excessively long (over 12 hours), the particles precipitated in the copper alloy structure grow large. As a result, the effect of precipitation strengthening decreases, and the release of strain in the copper alloy structure progresses sufficiently beyond the intended degree, and the synergistic effect of precipitation strengthening and work hardening obtained by the second cold rolling process Effect is lost. As a result, the tensile strength of the finally obtained copper alloy material may be insufficient. From this point of view, in the second heat treatment step, the second cold-rolled material is heated and held at a temperature of 380 ° C. or higher and 480 ° C. or lower for 1 hour or more and 12 hours or less. In order to obtain a copper alloy structure with well-balanced precipitation, heating and holding is performed at a temperature of 400° C. or higher and 460° C. or lower for 1 hour or longer and 12 hours or shorter (preferably 2 hours or longer and 8 hours or shorter).

(7) Third cold rolling step In the third cold rolling step, the second heat treated material produced in the second heat treatment step is used to perform cold rolling at a rolling reduction rate of 60% or more and 80% or less. to produce a third cold rolled material. Also, in this step, the final desired thickness of the copper alloy material (product thickness) can be obtained. In the third cold rolling step, dislocations are further introduced into and sufficiently accumulated in the copper alloy structure in which the particles of the second heat treated material produced in the second heat treatment step are dispersed and precipitated, and the copper alloy structure is changed. It is a step of further work hardening. As a result, the synergistic effect of precipitation strengthening and work hardening obtained by the second heat treatment step is sufficiently enhanced, so that the tensile strength of the finally obtained copper alloy material can be sufficiently improved.

If the degree of rolling reduction in the third cold rolling step is excessively small (less than 60%), the copper alloy structure may not be sufficiently work hardened, and the synergistic effect of precipitation strengthening and work hardening may not be sufficiently enhanced. . In addition, if the rolling reduction rate in the third cold rolling step is excessively large (more than 80%), the strain in the copper alloy structure is excessively accumulated, and the excessively accumulated strain is used in the following third heat treatment step. In some cases, the tensile strength of the finally obtained copper alloy material is not sufficiently improved due to excessive release beyond the degree of release. From this point of view, in the third cold rolling step, the second heat treated material produced in the second heat treatment step is cold rolled at a rolling reduction rate of 60% or more and 80% or less. In order to finally obtain a synergistic effect of precipitation strengthening and work hardening in a well-balanced manner, cold rolling is performed at a rolling workability of 65% or more and 75% or less.

(8) Third heat treatment step In the third heat treatment step, the third cold rolled material produced in the third cold rolling step is heated and held at a temperature of 250°C or higher and 380°C or higher for 4 hours or less. Then, the desired copper alloy material is produced. The heating and holding in this step may have a holding time of 0 h, that is, the temperature may be lowered as soon as the target holding temperature is reached after raising the temperature. This third heat treatment step moderately releases the strain accumulated in the copper alloy structure of the third cold-rolled material produced by the third cold rolling described above, and the target copper alloy material elongation and bending This is a process for improving mechanical properties such as workability. In the case of a conventional method for producing a copper alloy material made of a general Cu--Fe--P-based copper alloy, heat treatment (annealing) for the purpose of releasing strain is maintained at a temperature of, for example, 400° C. or higher and 500° C. or lower. done. On the other hand, in the third heat treatment step of the present invention, heating and holding is performed for 4 hours or less at a temperature of 250° C. or higher and 380° C. or lower, which is on the lower temperature side. By heating and holding at a lower temperature than in the past, the strain in the copper alloy structure caused by rolling is moderately released but not excessively released, and a copper alloy structure containing moderate strain is obtained. A decrease in tensile strength of the intended copper alloy material can be minimized.

If the heating and holding temperature in the third heat treatment step is excessively low (less than 250°C), the release of strain in the copper alloy structure of the third cold-rolled material becomes insufficient, resulting in the desired copper alloy material. Mechanical properties such as elongation and bendability may not be improved. In addition, if the heating and holding temperature in the third heat treatment step is excessively high (over 380 ° C.) or the heating and holding time is excessively long (over 4 hours), the strain in the copper alloy structure of the third cold rolled material is excessively released, and the desired tensile strength of the copper alloy material may not be obtained. From this point of view, in the third heat treatment step, the third cold-rolled material is heated and held at a temperature of 250 ° C. or higher and 380 ° C. or lower for 4 hours or less. In order to obtain a copper alloy structure with a good balance of elongation and bending workability, heating and holding at a temperature of 280° C. or more and 350° C. or less for 1 hour or less is performed.

As described above, according to the present invention, there is no problem of residual smut as with a copper alloy material made of a Cu-Fe-Zn-P-based copper alloy such as C1940, and a higher strength Cu-Ni such as C7025 - It is possible to provide a copper alloy material and a method for producing a copper alloy material that have substantially the same electrical conductivity (conductivity) and mechanical strength (tensile strength) as a copper alloy material made of a Si-based copper alloy. .

The effectiveness of the copper alloy material and the method of manufacturing the copper alloy material according to the present invention will be explained by citing actual evaluation results. First, Table 1 summarizes information such as compositions (additional elements), main manufacturing conditions, and mechanical properties of copper alloy materials of samples 1 to 29 (examples of the present invention and comparative examples). In addition, the copper alloy materials of Samples 30 and 31 are also shown as reference examples. Note that Mn was not intentionally added to samples 1 to 29. In addition, the remainder of samples 1 to 29 other than additive elements may be interpreted as Cu and impurity elements, and impurity elements (Ag, Pb, Ni, S, etc.) less than 0.01% are omitted.

The copper alloy material of Sample 1 shown in Table 1 contains 2.2% by mass of Fe, 0.03% by mass of P, 0.12% by mass of Zn, and 0.60% by mass of Sn. , the balance being Cu and impurity elements. This copper alloy material was produced through the following steps (1) to (8).
(1) In the melting and casting process, using a high-frequency melting furnace, an additive containing a predetermined additive element is added to a molten base material made of oxygen-free copper, and the like is added and melted in a nitrogen atmosphere. A copper alloy casting having a thickness of 25 mm, a width of about 30 mm and a length of about 150 mm was produced.
(2) In the hot rolling step, the copper alloy cast material was hot rolled while being heated to a temperature of about 950°C to produce a hot rolled material having a thickness of about 8 mm.
(3) In the first cold-rolling step, the hot-rolled material is cold-rolled to a rolling reduction rate of about 83% in total to produce a first cold-rolled material having a thickness of about 1.4 mm. did.
(4) In the first heat treatment step, the first cold-rolled material was heated and held at a temperature of about 580°C for about 3 minutes to produce a first heat-treated material.
(5) In the second cold rolling step, the first heat-treated material is cold-rolled to a rolling reduction rate of about 64% in total to produce a second cold-rolled material having a thickness of about 0.5 mm. did. In this case, the total rolling workability of the first cold rolling step and the second cold rolling step is about 94%.
(6) In the second heat treatment step, the second cold-rolled material was heated and held at a temperature of about 450°C for about 4 hours to produce a second heat-treated material.
(7) In the third cold-rolling step, the second heat-treated material is cold-rolled to a rolling reduction rate of about 70% in total to produce a third cold-rolled material having a thickness of about 0.15 mm. did. In this case, the total rolling workability of the second cold rolling step and the third cold rolling step is about 89%, and the rolling workability of the first cold rolling step, the second cold rolling step and the third cold rolling step is The total rolling workability is about 98%.
(8) In the third heat treatment step, the third cold-rolled material is heated and held at a temperature of about 350 ° C. for about 1 minute, and finally the copper alloy of sample 1 having a thickness of about 0.15 mm got the wood. The copper alloy material of Sample 1 is an example of the present invention.

The copper alloy material of sample 2 shown in Table 1 is substantially the same as the copper alloy material of sample 1 except that the heating and holding in the second heat treatment step is set to a temperature of about 420 ° C. in the manufacturing process of the copper alloy material of sample 1. Through the same manufacturing process, it was finally manufactured to have the same thickness as the copper alloy material of Sample 1. The copper alloy material of sample 2 is an example of the present invention.

For the copper alloy material of sample 3 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, the heating and holding temperature in the second heat treatment step is set to about 420 ° C., and the heating and holding temperature in the third heat treatment step is set to about 280 ° C. It was manufactured through substantially the same manufacturing process as the copper alloy material of sample 1 except that the temperature was set to 10°C, and finally had the same thickness as the copper alloy material of sample 1. The copper alloy material of Sample 3 is an example of the present invention.

In the copper alloy material of sample 4 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, Sn contained in the copper alloy material finally obtained by adjusting the composition in the melting and casting process is about 0.30% by mass. It was produced through substantially the same manufacturing process as the copper alloy material of sample 1 except that it was made to have a thickness equivalent to that of the copper alloy material of sample 1 finally. The copper alloy material of Sample 4 is an example of the present invention.

For the copper alloy material of sample 5 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, the heating and holding in the first heat treatment step was set to a temperature of about 550 ° C., and the rolling workability in the second cold rolling step was was set to about 73%, the heating and holding in the second heat treatment step was set to a temperature of about 420 ° C., and the rolling reduction in the third cold rolling step was set to about 60%, except that the copper alloy of sample 1 After going through substantially the same manufacturing process as the material, it was finally manufactured to have the same thickness as the copper alloy material of sample 1. In this case, the total rolling workability of the second cold rolling step and the third cold rolling step is about 89%. The copper alloy material of sample 5 is an example of the present invention.

For the copper alloy material of sample 6 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, the heating and holding in the first heat treatment step was set to a temperature of about 550 ° C., and the rolling workability in the second cold rolling step was was set to about 46%, and the rolling workability in the third cold rolling step was set to about 80%. It is manufactured so as to have the same thickness as the alloy material. In this case, the total rolling workability of the second cold rolling step and the third cold rolling step is about 89%. The copper alloy material of Sample 6 is an example of the present invention.

For the copper alloy material of sample 7 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, the rolling reduction in the second cold rolling step was set to about 73%, and the heating and holding in the second heat treatment step was set to about 73%. Except that the temperature was set to 420 ° C. and the rolling workability in the third cold rolling step was set to about 60%, the manufacturing process was substantially the same as that of the copper alloy material of sample 1, and finally the copper of sample 1 It is manufactured so as to have the same thickness as the alloy material. The copper alloy material of sample 7 is an example of the present invention.

For the copper alloy material of sample 8 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, the heating and holding in the first heat treatment step was set to a temperature of about 600 ° C., and the rolling workability in the second cold rolling step was was set to about 73%, the heating and holding in the second heat treatment step was set to a temperature of about 420 ° C., and the rolling reduction in the third cold rolling step was set to about 60%, except that the copper alloy of sample 1 After going through substantially the same manufacturing process as the material, it was finally manufactured to have the same thickness as the copper alloy material of sample 1. The copper alloy material of Sample 8 is an example of the present invention.

For the copper alloy material of sample 9 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, the heating and holding in the first heat treatment step was set to a temperature of about 600 ° C., and the rolling workability in the second cold rolling step was was set to about 46%, and the rolling workability in the third cold rolling step was set to about 80%. It is manufactured so as to have the same thickness as the alloy material. The copper alloy material of sample 9 is an example of the present invention.

In the copper alloy material of sample 10 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, Fe contained in the copper alloy material finally obtained by adjusting the composition in the melting and casting process is about 1.50% by mass. It was produced through substantially the same manufacturing process as the copper alloy material of sample 1 except that it was made to have a thickness equivalent to that of the copper alloy material of sample 1 finally. The copper alloy material of Sample 10 is a comparative example in which the Fe content is outside the scope of the present invention.

In the copper alloy material of sample 11 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, Fe contained in the copper alloy material finally obtained by adjusting the composition in the melting and casting process is about 2.80% by mass. It was produced through substantially the same manufacturing process as the copper alloy material of sample 1 except that it was made to have a thickness equivalent to that of the copper alloy material of sample 1 finally. The copper alloy material of sample 11 is a comparative example, and the Fe content is outside the scope of the present invention.

In the copper alloy material of sample 12 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, the P contained in the copper alloy material finally obtained by adjusting the composition in the melting and casting process is about 0.22% by mass. It was produced through substantially the same manufacturing process as the copper alloy material of sample 1 except that it was made to have a thickness equivalent to that of the copper alloy material of sample 1 finally. The copper alloy material of sample 12 is an example of the present invention.

In the copper alloy material of sample 13 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, about 0.40% by mass of Zn is contained in the copper alloy material finally obtained by adjusting the composition in the melting and casting process. It was produced through substantially the same manufacturing process as the copper alloy material of sample 1 except that it was made to have a thickness equivalent to that of the copper alloy material of sample 1 finally. The copper alloy material of sample 13 is a comparative example, and the Zn content is outside the scope of the present invention.

In the copper alloy material of sample 14 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, Sn contained in the copper alloy material finally obtained by adjusting the composition in the melting and casting process is about 0.20% by mass. It was produced through substantially the same manufacturing process as the copper alloy material of sample 1 except that it was made to have a thickness equivalent to that of the copper alloy material of sample 1 finally. The copper alloy material of sample 14 is a comparative example, and the Sn content is outside the scope of the present invention.

In the copper alloy material of sample 15 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, Sn contained in the copper alloy material finally obtained by adjusting the composition in the melting and casting process is about 0.90% by mass. It was produced through substantially the same manufacturing process as the copper alloy material of sample 1 except that it was made to have a thickness equivalent to that of the copper alloy material of sample 1 finally. The copper alloy material of sample 15 is a comparative example, and the Sn content is outside the scope of the present invention.

In the copper alloy material of sample 16 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, Sn contained in the copper alloy material finally obtained by adjusting the composition in the melting and casting process is about 0.30% by mass. Except that the heating and holding in the first heat treatment step was set to a temperature of about 450 ° C., the manufacturing process was substantially the same as the copper alloy material of sample 1, and finally the same as the copper alloy material of sample 1. It is made to have a thickness of The copper alloy material of sample 16 is a comparative example, and the first heat treatment step is outside the scope of the present invention.

The copper alloy material of sample 17 shown in Table 1 is substantially the same as the copper alloy material of sample 1 except that the heating and holding in the first heat treatment step is set to a temperature of about 650 ° C. in the manufacturing process of the copper alloy material of sample 1. Through the same manufacturing process, it was finally manufactured to have the same thickness as the copper alloy material of Sample 1. The copper alloy material of sample 17 is a comparative example, and the first heat treatment step is outside the scope of the present invention.

The copper alloy material of sample 18 shown in Table 1 is substantially the same as the copper alloy material of sample 1 except that the heating and holding time in the first heat treatment step was set to about 5 hours in the manufacturing process of the copper alloy material of sample 1. Through the manufacturing process of 1, it was finally manufactured to have a thickness equivalent to that of the copper alloy material of sample 1. The copper alloy material of sample 18 is a comparative example, and the first heat treatment step is outside the scope of the present invention.

For the copper alloy material of sample 19 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, the rolling reduction rate in the second cold rolling step was set to about 17%, and the rolling reduction in the third cold rolling step was Except for setting the degree of hardness to about 80%, it was manufactured to have a thickness equivalent to that of the copper alloy material of Sample 1 after undergoing substantially the same manufacturing process as that of the copper alloy material of Sample 1. . In this case, the total rolling workability of the second cold rolling step and the third cold rolling step is about 83%. The copper alloy material of sample 19 is a comparative example, and the second cold rolling step is outside the scope of the present invention.

For the copper alloy material of sample 20 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, the rolling reduction rate in the second cold rolling step was set to about 91%, and the rolling reduction in the third cold rolling step was Except for setting the degree of hardness to about 60%, the copper alloy material was manufactured through substantially the same manufacturing process as the copper alloy material of sample 1, and finally manufactured to have the same thickness as the copper alloy material of sample 1. . In this case, the total rolling workability of the second cold rolling step and the third cold rolling step is about 96%. The copper alloy material of sample 20 is a comparative example, and the second cold rolling step is outside the scope of the present invention.

The copper alloy material of sample 21 shown in Table 1 is substantially the same as the copper alloy material of sample 1 except that the heating and holding in the second heat treatment step was set to a temperature of about 350 ° C. in the manufacturing process of the copper alloy material of sample 1. Through the same manufacturing process, it was finally manufactured to have the same thickness as the copper alloy material of Sample 1. The copper alloy material of sample 21 is a comparative example, and the second heat treatment step is outside the scope of the present invention.

The copper alloy material of sample 22 shown in Table 1 is substantially the same as the copper alloy material of sample 1 except that the heating and holding in the second heat treatment step was set to a temperature of about 500 ° C. in the manufacturing process of the copper alloy material of sample 1. Through the same manufacturing process, it was finally manufactured to have the same thickness as the copper alloy material of Sample 1. The copper alloy material of Sample 22 is a comparative example, and the second heat treatment step is outside the scope of the present invention.

The copper alloy material of sample 23 shown in Table 1 is the sample 1 except that the heating and holding in the second heat treatment step is set to a temperature of about 420 ° C. for about 0.5 hours in the manufacturing process of the copper alloy material of sample 1. After going through substantially the same manufacturing process as the copper alloy material of sample 1, it was finally manufactured to have the same thickness as the copper alloy material of sample 1. The copper alloy material of sample 23 is a comparative example, and the second heat treatment step is outside the scope of the present invention.

The copper alloy material of sample 24 shown in Table 1 is the manufacturing process of the copper alloy material of sample 1, except that the heating and holding in the second heat treatment step is set to a temperature of about 450 ° C. for about 20 hours. It was manufactured so as to have a thickness equivalent to that of the copper alloy material of the sample 1 through a manufacturing process substantially equivalent to that of the copper alloy material. The copper alloy material of Sample 24 is a comparative example, and the second heat treatment step is outside the scope of the present invention.

For the copper alloy material of sample 25 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, the rolling reduction rate in the second cold rolling process was set to about 79%, and the rolling reduction in the third cold rolling process was Except for setting the degree of hardness to about 50%, the copper alloy material of sample 1 was manufactured through substantially the same manufacturing process as that of the copper alloy material of sample 1, and finally manufactured to have the same thickness as the copper alloy material of sample 1. . In this case, the total rolling workability of the second cold rolling step and the third cold rolling step is about 90%. The copper alloy material of sample 25 is a comparative example, and the third cold rolling step is outside the scope of the present invention.

For the copper alloy material of sample 26 shown in Table 1, in the manufacturing process of the copper alloy material of sample 1, the rolling reduction rate in the second cold rolling step was set to about 28%, and the rolling reduction in the third cold rolling step was Except for setting the degree of hardness to about 85%, it was manufactured so as to have the same thickness as the copper alloy material of Sample 1 after undergoing substantially the same manufacturing process as that of the copper alloy material of Sample 1. . In this case, the total rolling workability of the second cold rolling step and the third cold rolling step is about 89%. The copper alloy material of sample 26 is a comparative example, and the third cold rolling step is outside the scope of the present invention.

The copper alloy material of sample 27 shown in Table 1 is substantially the same as the copper alloy material of sample 1 except that the heating and holding in the third heat treatment step was set to a temperature of about 200 ° C. in the manufacturing process of the copper alloy material of sample 1. Through the same manufacturing process, it was finally manufactured to have the same thickness as the copper alloy material of Sample 1. The copper alloy material of sample 27 is a comparative example, and the third heat treatment step is outside the scope of the present invention.

The copper alloy material of sample 28 shown in Table 1 is substantially the same as the copper alloy material of sample 1 except that the heating and holding in the third heat treatment step was set to a temperature of about 400 ° C. in the manufacturing process of the copper alloy material of sample 1. Through the same manufacturing process, it was finally manufactured to have the same thickness as the copper alloy material of Sample 1. The copper alloy material of sample 28 is a comparative example, and the third heat treatment step is outside the scope of the present invention.

The copper alloy material of sample 29 shown in Table 1 is substantially the same as the copper alloy material of sample 1 except that the heating and holding time in the third heat treatment step was set to about 5 hours in the manufacturing process of the copper alloy material of sample 1. Through the manufacturing process of 1, it was finally manufactured to have a thickness equivalent to that of the copper alloy material of sample 1. The copper alloy material of sample 29 is a comparative example, and the third heat treatment step is outside the scope of the present invention.

The copper alloy material of sample 30 shown in Table 1 has a composition corresponding to C1940 (Cu-2.2% by mass Fe-0.03% by mass P-0.12% by mass Zn), and the temper is ESH. It is a commercially available material having the same thickness as the copper alloy material of Sample 1. The copper alloy material of sample 30 is a reference example.

The copper alloy material of Sample 31 shown in Table 1 has a composition equivalent to C7025 (Cu-3% by mass Ni-0.65% by mass Si-0.15% by mass Mg) and has a temper of 1/2 H It is a commercially available material having a thickness equivalent to that of the copper alloy material of Sample 1. The copper alloy material of sample 31 is a reference example.

Regarding the properties of the copper alloy materials of Samples 1 to 31 described above, as shown in Table 1, attention was focused on tensile strength, electrical conductivity, bending workability, and the presence or absence of residual smut, and they were actually confirmed and evaluated. Specifically, the tensile strength of the copper alloy material was measured in accordance with JIS-Z2241:2011, which defines a tensile test method for metallic materials, under a normal temperature environment (approximately 20°C). Further, the electrical conductivity of the copper alloy material was measured in a room temperature environment (approximately 20° C.) in accordance with JIS-Z0505:1975, which defines methods for measuring the electrical conductivity of non-ferrous metal materials. In addition, the bending workability of the copper alloy material was evaluated by the W bending test, which is adopted as a bending test in JIS-H3110:2018, in a room temperature environment (about 20°C). Specifically, when the test piece (copper alloy material) is bent with a bending radius (inner radius) of 0.15 mm, the case where no cracks are confirmed on the outer surface of the bending of the test piece is evaluated as "excellent". A case where cracks were confirmed even if they were minute was evaluated as "poor". The presence or absence of residual smut was confirmed by observing the surface of the test piece (copper alloy material) that had been pretreated, immersed in a chemical polishing liquid for about 1 minute, washed with water, and dried. At this time, the chemical polishing liquid was an acidic aqueous solution containing about 20% by mass of sulfuric acid and about 8% by mass of hydrogen peroxide, and was kept at about 40.degree. The surface area of the test piece to be immersed in the chemical polishing liquid was set to about 2000 mm ² (front and back surfaces with a width of 20 mm and a length of 50 mm). The pretreatment of the specimen to be tested was carried out in the order of ethanol degreasing, alkaline electrolytic degreasing, immersion (neutralization) in a 5% sulfuric acid aqueous solution, washing with water, and drying.

Regarding the reference example shown in Table 1, the copper alloy material of sample 30 had a tensile strength of 540 MPa, which was less than 620 MPa. The electrical conductivity was 63.0%IACS, which was 40.0%IACS or more. The bending workability was "excellent" and the residual smut was "absent". Moreover, the copper alloy material of sample 31 had a tensile strength of 650 MPa, which was 620 MPa or more. The electrical conductivity was 45.0%IACS, which was 40.0%IACS or more. The bending workability was evaluated as "excellent", and the residual smut was evaluated as "present".

<Influence of Fe>
The copper alloy materials of samples 1, 10 and 11 shown in Table 2 (extracted from Table 1) were different in Fe content of the copper alloy material finally obtained by adjusting the composition in the melting and casting process. They are manufactured to have substantially the same thickness through substantially the same manufacturing process. Specifically, since the Fe content of sample 1 is 2.20%, it falls within the range of 1.6% or more and 2.6% or less defined in the present invention. In contrast, Sample 10 has a lower 1.50% by weight and Sample 11 has a higher 2.80%, which is outside the above range.

As shown in Table 2, the tensile strength was 670 MPa for sample 1 and 672 MPa for sample 11, both of which were 620 MPa or more. On the other hand, Sample 10 was 575 MPa, which was less than 620 MPa. The electrical conductivity was 48.2%IACS for sample 1 and 56.3%IACS for sample 10, both of which were 40.0%IACS or higher. In contrast, sample 11 resulted in 38.8% IACS and less than 40.0% IACS. Further, the bending workability of sample 11 was "poor" while samples 1 and 10 were "excellent". Moreover, all of Samples 1, 10 and 11 had "no" residual smut.

A comparative evaluation of the copper alloy materials of Samples 1, 10 and 11 with different Fe contents showed that when the Fe content was small and outside the above range, the tensile strength of the copper alloy material decreased and reached 620 MPa. It turned out not to. Further, it was found that when the Fe content becomes large and falls outside the above range, the electrical conductivity of the copper alloy material decreases and does not reach 40.0% IACS. It was also found that the Fe content hardly affects the bending workability and residual smut of the copper alloy material. Therefore, from the viewpoint of having no residual smut, having a tensile strength of 620 MPa or more, having a conductivity of 40.0% IACS or more, and having good bending workability, it is practically 1.6% A copper alloy material containing 2.6% or more of Fe is effective.

<Influence of P>
The copper alloy materials of samples 1 and 12 shown in Table 3 (extracted from Table 1) are substantially the same except that the P content of the finally obtained copper alloy material is changed by adjusting the composition in the melting and casting process. It is manufactured so as to have substantially the same thickness through the manufacturing process of Specifically, since the P content of Sample 1 is 0.03%, it falls within the range of 0.01% or more and 0.3% or less specified in the present invention. Further, the content of sample 12 is 0.22% by mass, which is larger than that of sample 1, which is within the above range, but is outside the range of 0.01% or more and 0.20% or less, which the inventor considers more preferable.

As shown in Table 3, the tensile strength of both samples 1 and 12 was 620 MPa or more, and sample 12 was 675 MPa, which was larger than sample 1 (670 MPa). Also, the electrical conductivity was 40.0% IACS or more for both samples 1 and 12, and sample 12 was 48.8% IACS, which is higher than sample 1 (48.2% IACS). In addition, the bending workability of sample 12 was "poor" while sample 1 was "excellent". Also, residual smut was "absent" for both samples 1 and 12.

A comparative evaluation of the copper alloy materials of samples 1 and 12 with different P contents revealed that the P content hardly affected the tensile strength and electrical conductivity of the copper alloy materials. In addition, it was found that when the P content increases, the bending workability of the copper alloy material tends to deteriorate. It was also found that the P content hardly affects the residual smut of the copper alloy material. Therefore, from the viewpoint of having no residual smut, having a tensile strength of 620 MPa or more, and having an electrical conductivity of 40.0% IACS or more, it is practically 0.01% or more and 0.3% or less specified in this invention. A copper alloy material containing P is effective. In addition, from the viewpoint of good bending workability, a copper alloy material containing 0.01% or more and 0.20% or less of P is practically effective.

<Influence of Zn>
The copper alloy materials of samples 1 and 13 shown in Table 4 (extracted from Table 1) are substantially the same except that the Zn content of the finally obtained copper alloy material is changed by adjusting the composition in the melting and casting process. It is manufactured so as to have substantially the same thickness through the manufacturing process of Specifically, since the Zn content in Sample 1 is 0.12%, it falls within the range of 0.01% to 0.3% specified in the present invention. In contrast, Sample 13 has a higher 0.40% and is therefore outside the above range.

As shown in Table 4, the tensile strength of both samples 1 and 12 was 620 MPa or more, and sample 13 was 674 MPa, which was larger than sample 1 (670 MPa). Also, the electrical conductivity of sample 13 was 39.2%IACS, which was less than 40.0%IACS, compared to sample 1 (48.2%IACS), which was 40.0%IACS or more. In addition, the bending workability of sample 13 was "poor" while sample 1 was "excellent". Also, residual smut was "absent" for both samples 1 and 13.

According to a comparative evaluation of the copper alloy materials of Samples 1 and 13 with different Zn contents, when the Zn content increases and falls outside the above range, the electrical conductivity of the copper alloy material decreases to 40.0% IACS. It was found that the bending workability of the copper alloy material tended to deteriorate. It was also found that the Zn content hardly affects the tensile strength and residual smut of the copper alloy material. Therefore, from the viewpoint of having no residual smut, having a tensile strength of 620 MPa or more, having a conductivity of 40.0% IACS or more, and having good bending workability, it is practically 0.01% A copper alloy material containing 0.3% or more of Zn is effective.

<Influence of Sn>
The copper alloy materials of samples 1, 4, 14 and 15 shown in Table 5 (extracted from Table 1) were different in Sn content of the copper alloy material finally obtained by adjusting the composition in the melting and casting process. are manufactured to have substantially the same thickness through substantially the same manufacturing process. Specifically, the Sn content is 0.60% in Sample 1 and 0.30% in Sample 13, and is within the range of 0.3% to 0.8% specified in the present invention. . In contrast, Sample 4 has a lower 0.20% by weight and Sample 14 has a higher 0.90%, which is outside the above range.

As shown in Table 5, the tensile strength of samples 1, 4 and 15 was 620 MPa or more, and sample 14 was less than 620 MPa. Specifically, compared to the tensile strength of sample 1 (670 MPa), sample 4 was smaller at 624 MPa, sample 14 was even smaller at 604 MPa, while sample 15 was larger at 690 MPa. In terms of electrical conductivity, Samples 1, 4 and 14 were 40.0%IACS or more, and Sample 15 was less than 40.0%IACS. Specifically, relative to the conductivity of sample 1 (48.2% IACS), sample 4 was greater at 51.0% IACS and sample 14 was even greater at 55.0% IACS, whereas sample 15 was smaller at 39.8% IACS. Further, the bending workability of Sample 15 was "poor" while Samples 1, 4 and 14 were "excellent". In addition, all of samples 1, 4, 14 and 15 were found to have no residual smut.

A comparative evaluation of the copper alloy materials of samples 1, 4, 14 and 15 with different Sn contents revealed that the tensile strength of the copper alloy materials tended to decrease as the Sn content decreased. In addition, it was found that when the Sn content was further decreased and fell outside the above range, the tensile strength of the copper alloy material did not reach 620 MPa. Further, a comparative evaluation of the copper alloy materials of Samples 1 and 4 revealed that when the copper alloy material contained more than 0.3% Sn, a tensile strength of 625 MPa or more was obtained. It was also found that the electrical conductivity of the copper alloy material tends to increase as the Sn content decreases. Further, it was found that when the Sn content becomes large and falls outside the above range, the electrical conductivity of the copper alloy material further decreases and does not reach 40.0%IACS. In addition, it was found that when the Sn content increases, the bending workability of the copper alloy material tends to deteriorate. Also, it was found that the Sn content hardly affects the residual smut. Therefore, from the viewpoint of having no residual smut, having a tensile strength of 620 MPa or more, having a conductivity of 40.0% IACS or more, and having good bending workability, it is practically 0.3% A copper alloy material containing 0.8% or more of Sn is effective.

<Influence of the first heat treatment step>
Focusing on the copper alloy materials of samples 1, 4, 16, 17 and 18 shown in Table 6 (extracted from Table 1), the influence of the first heat treatment step will be described. The copper alloy materials of Samples 1, 16, 17 and 18 were manufactured to have substantially the same thickness through substantially the same manufacturing process except that the heating and holding conditions in the first heat treatment step were changed. It is a thing. In addition, the copper alloy materials of samples 1, 17 and 18 were adjusted so that the Sn content was 0.60%, and the copper alloy materials of samples 4 and 16 were adjusted so that the Sn content was 0.30%. The ingredients are adjusted. Specifically, the heating and holding conditions in the first heat treatment step are within the range of 500° C. or higher and 600° C. or lower and 4 hours or shorter as defined in the present invention, since Samples 1 and 4 are heated at 580° C. for about 3 minutes. In contrast, sample 16 is at a lower temperature of 450° C. and sample 17 is at a higher temperature of 650° C., so the retention times are similar to samples 1 and 4, but outside the above range. Also, since sample 18 is longer, about 5 hours, the holding temperature is similar to samples 1 and 4, but outside the above range.

As shown in Table 6, the tensile strength of sample 1 (670 MPa), which is 620 MPa or more, was as small as 624 MPa due to the Sn content of sample 4 being smaller than that of sample 1, but 620 MPa. That was it. On the other hand, sample 16, which is out of the above range for low temperature retention, has a value of 610 MPa, sample 17, which is out of the above range for high temperature retention, has a value of 596 MPa, and sample 18, which is out of the above range for long term retention. was 612 MPa, and both of these were less than 620 MPa. Also, the electrical conductivity is 51.0% IACS for samples 4 and 18, 50.5% IACS for sample 16, and 50.5% IACS for sample 1 (48.2% IACS), which is 40.0% IACS or more. 17 resulted in 51.8% IACS, both of which were greater than Sample 1. In addition, the bending workability of samples 1, 16, 17 and 18 were all "excellent". In addition, all samples 1, 16, 17 and 18 were found to have no residual smut.

Comparative evaluation of the copper alloy materials of samples 1 and 17 with different heating and holding temperatures in the first heat treatment step and comparative evaluation of the copper alloy materials of samples 4 and 16 showed that the heating and holding temperature in the first heat treatment step was high or low. It has been found that if the tensile strength is outside the above range, the tensile strength of the copper alloy material tends to decrease and not reach 620 MPa. Further, according to a comparative evaluation of the copper alloy materials of Samples 1 and 18, if the heating and holding in the first heat treatment step is prolonged and is outside the above range, the tensile strength of the copper alloy material decreases and does not reach 620 MPa. It turned out that there is a trend. In addition, a comparative evaluation of the copper alloy materials of Samples 1, 4, 16, 17 and 18 revealed that the heating and holding conditions in the first heat treatment step do not easily affect the electrical conductivity, bending workability, and residual smut of the copper alloy material. There was found. Therefore, it has no residual smut, has a tensile strength of 620 MPa or more, has a conductivity of 40.0% IACS or more, and in addition has good bending workability. The first heat treatment step of producing the first heat-treated material by heating and holding the rolled material at a temperature of 500° C. or more and 600° C. or less for 4 hours or less is effective.

<Influence of rolling workability in the second cold rolling step>
Focusing on the copper alloy materials of samples 1, 6, 19 and 20 shown in Table 7 (extracted from Table 1), the influence of the second cold rolling step will be described. The copper alloy materials of Samples 1, 6, 19 and 30 were made to have substantially the same thickness through substantially the same manufacturing process except that the degree of rolling work in the second cold rolling process was changed. It is manufactured. Specifically, the degree of rolling reduction in the second cold rolling step is 64% for sample 1 and 46% for sample 6, and therefore falls within the range of 20% to 90% specified in the present invention. In contrast, sample 19 is 17% and sample 20 is 91%, which are outside the above range.

As shown in Table 7, the tensile strength of sample 1 (670 MPa), which is 620 MPa or more, is as small as 654 MPa for sample 6, which has a reduced degree of rolling. Although the sample 19 with the same value was further reduced to 624 MPa, all of them were 620 MPa or more. On the other hand, Sample 20, in which the degree of rolling was increased to be outside the above range, was 610 MPa, which was even lower, and was less than 620 MPa. Further, the electrical conductivity of sample 1 (48.2% IACS), which is 40.0% IACS or more, is 48.8% IACS for sample 20, which is out of the above range by increasing the degree of rolling. was at the same level. On the other hand, Sample 6, in which the degree of rolling work was reduced, was as small as 45.8% IACS. Sample 19, in which the degree of rolling work was further reduced to be outside the above range, was further reduced to 39.6%IACS, which was less than 40.0%IACS. In addition, the bending workability of samples 1, 6, 19 and 20 were all "excellent". In addition, all of samples 1, 6, 19 and 20 were "absent" with respect to residual smut.

Comparative evaluation of the copper alloy materials of Samples 1, 6 and 19, which differed in the degree of rolling reduction in the second cold rolling process, showed that the tensile strength of the copper alloy material increased as the degree of rolling reduction in the second cold rolling process decreased. A decreasing trend was found. In addition, a comparative evaluation of the copper alloy materials of Samples 1, 6, 19 and 20 revealed that when the degree of rolling work in the second cold rolling step is excessively outside the above range, the tensile strength of the copper alloy material decreases. It was found that the pressure did not reach 620 MPa. Further, by comparative evaluation of the copper alloy materials of Samples 1, 6, 19 and 20, even if the degree of rolling workability in the second cold rolling step is excessively outside the above range, the electrical conductivity of the copper alloy material does not change. It has been found that the electrical conductivity of the copper alloy material is lowered and does not reach 40.0% IACS when it is too small and is outside the above range. In addition, a comparative evaluation of the copper alloy materials of Samples 1, 6, 19 and 20 revealed that the degree of rolling workability in the second cold rolling step does not easily affect the bending workability and residual smut of the copper alloy material. . Therefore, from the viewpoint of having no residual smut, having a tensile strength of 620 MPa or more, having a conductivity of 40.0% IACS or more, and having good bending workability, it is practically the first heat-treated material The second cold rolling step of cold rolling at a rolling reduction ratio of 20% or more and 90% or less to produce the second cold rolled material is effective.

<Influence of heating and holding conditions in the second heat treatment step>
Focusing on the copper alloy materials of samples 1, 21, 22, 23 and 24 shown in Table 8 (extracted from Table 1), the influence of the second heat treatment step will be described. The copper alloy materials of Samples 1, 21, 22, 23 and 24 were made to have substantially the same thickness through substantially the same manufacturing process except that the heating and holding conditions in the second heat treatment step were changed. It is manufactured. Specifically, the heating and holding conditions in the second heat treatment step are within the range of 380° C. to 480° C. and 1 hour to 12 hours as defined in the present invention, since the sample 1 is heated at 450° C. for about 4 hours. In contrast, sample 21 is at a lower temperature of 350° C. and sample 22 is at a higher temperature of 500° C., so the retention time is similar to sample 1, but outside the ranges given above. Also, sample 23 is shorter, about 0.5 hours, and sample 24 is longer, about 20 hours, so the holding temperature is within the above range, but the holding time is outside the above range.

As shown in Table 8, the tensile strength is sample 1 (670 MPa), which is 620 MPa or more, and sample 21 (606 MPa) and sample 22 (575 MPa), which are outside the above range for low or high temperature retention, and , Sample 23 (598 MPa) and Sample 24 (602 MPa), both of which were out of the above range for short-term or long-term retention, decreased to less than 620 MPa. In addition, the electrical conductivity of sample 1 (48.2% IACS), which is 40.0% IACS or more, is out of the above range for low temperature retention, and sample 21 (38.0% IACS) is used for a short time. Sample 23 (39.7% IACS), whose retention was outside the above range, both decreased to less than 40.0% IACS. In addition, both Sample 22 (50.5% IACS), which is outside the above range for high temperature retention, and Sample 24 (52.0% IACS), which is outside the above range for long-term retention, are got bigger. In addition, the bending workability of samples 1, 21, 22, 23 and 24 were all "excellent". In addition, all samples 1, 21, 22, 23 and 24 were found to have no residual smut.

By comparative evaluation of the copper alloy materials of Samples 1, 21, 22, 23 and 24 with different heating and holding temperatures in the second heat treatment step, the heating and holding temperature in the second heat treatment step became high or low and fell outside the above range. Then, it was found that the tensile strength of the copper alloy material tended to decrease and not reach 620 MPa. Further, according to a comparative evaluation of the copper alloy materials of Samples 1, 21 and 23, when the heating and holding in the second heat treatment step is at a low temperature or for a short time and is outside the above range, the electrical conductivity of the copper alloy material decreases to 40%. It was found that there was a tendency to not reach .0% IACS. Further, a comparative evaluation of the copper alloy materials of Samples 1, 22 and 24 revealed that the electrical conductivity of the copper alloy material tends to increase when the heating and holding time in the second heat treatment step is high or long. In addition, a comparative evaluation of the copper alloy materials of Samples 1, 21, 22, 23 and 24 revealed that the heating and holding conditions in the second heat treatment step had little effect on the bending workability and residual smut of the copper alloy materials. . Therefore, there is no residual smut, it has a tensile strength of 620 MPa or more, has an electrical conductivity of 40.0% IACS or more, and in addition, has good bending workability. A second heat treatment step in which the rolled material is heated and held at a temperature of 380° C. or more and 480° C. or less for 1 hour or more and 12 hours or less to produce the second heat treated material is effective.

<Influence of rolling workability of the third cold rolling>
Focusing on the copper alloy materials of samples 1, 25 and 26 shown in Table 9 (extracted from Table 1), the influence of the third cold rolling process will be described. The copper alloy materials of Samples 1, 25, and 26 were manufactured to have substantially the same thickness through substantially the same manufacturing process, except that the degree of rolling workability in the third cold rolling step was made different. It is a thing. Specifically, since the rolling workability of the third cold rolling step is 70% for the sample 1, it falls within the range of 60% or more and 80% or less specified in the present invention. On the other hand, sample 25 is 50% and sample 26 is 85%, which are outside the above range.

As shown in Table 9, the tensile strength is sample 1 (670 MPa), which is 620 MPa or more, and sample 25 (569 MPa), which is out of the above range by reducing the degree of rolling, and increasing the degree of rolling. All of Sample 26 (580 MPa), which was out of the above range, decreased to less than 620 MPa. In addition, the electrical conductivity of sample 1 (48.2% IACS), which is 40.0% IACS or more, is reduced to the extent of rolling and is outside the above range, sample 25 (48.2% IACS). Sample 26 (46.0% IACS), which was made to be outside the above range by increasing the degree of rolling, did not fall below 40.0% IACS, but was smaller than Sample 1. In addition, the bendability of samples 1, 25 and 26 was all "excellent". In addition, all of samples 1, 25 and 26 were "absent" with respect to residual smut.

A comparative evaluation of the copper alloy materials of Samples 1, 25 and 26 with different degrees of rolling reduction in the third cold rolling step revealed that when the degree of rolling reduction in the third cold rolling step was outside the above range, the copper alloy material It was found that the tensile strength tends to decrease and not reach 620 MPa. Further, it was found that even if the degree of rolling workability in the third cold rolling step becomes smaller and falls outside the above range, there is a tendency that the electrical conductivity of the copper alloy material is less likely to be affected. Further, it was found that when the degree of rolling workability in the third cold rolling step becomes large and falls outside the above range, the electrical conductivity of the copper alloy material tends to decrease. Moreover, it was found that the degree of rolling workability in the third cold rolling step does not easily affect the bending workability and residual smut of the copper alloy material. Therefore, from the viewpoint of having no residual smut, having a tensile strength of 620 MPa or more, having a conductivity of 40.0% IACS or more, and having good bending workability, the second heat-treated material is practically used. The third cold-rolling step of producing the third cold-rolled material by cold-rolling at a rolling reduction ratio of 60% or more and 80% or less using is effective.

<Influence of heating and holding conditions in the third heat treatment step>
Focusing on the copper alloy materials of samples 1, 27, 28 and 29 shown in Table 10 (extracted from Table 1), the influence of the third heat treatment step will be described. The copper alloy materials of Samples 1, 27, 28, and 29 were manufactured to have substantially the same thickness through substantially the same manufacturing process, except that the heating and holding conditions in the third heat treatment step were changed. It is a thing. Specifically, the heating and holding conditions of the third heat treatment step are within the range of 250° C. or higher and 380° C. or higher and 4 hours or shorter as defined in the present invention, since the sample 1 is heated at 430° C. for about 1 minute. In contrast, sample 27 is at a lower temperature of 200° C. and sample 28 is at a higher temperature of 400° C., so the retention times are similar to those of sample 1, but outside the ranges given above. Also, sample 29 is longer, about 5 hours, so the holding temperature is similar to sample 1, but the holding time is outside the above range.

As shown in Table 10, the tensile strength of Sample 1 (670 MPa), which is 620 MPa or more, is higher than that of Sample 27 (718 MPa), which is outside the above range for low temperature retention. Sample 28 (603 MPa), which was outside the above range, decreased to less than 620 MPa. In addition, the conductivity of sample 1 (48.2% IACS), which is 40.0% IACS or more, is about the same for sample 28 (48.2% IACS), which is outside the above range for maintaining high temperatures. However, Sample 27 (39.8% IACS), which was outside the above range for low temperature retention, decreased to less than 40.0% IACS. Further, the bending workability of sample 27 was "poor" while samples 1, 28 and 29 were "excellent". In addition, all of samples 1, 27, 28 and 29 had residual smut of "no".

Comparative evaluation of the copper alloy materials of samples 1 and 28 with different heating and holding temperatures in the third heat treatment step and comparative evaluation of the copper alloy materials of samples 1 and 29 showed that the heating and holding temperature in the third heat treatment step was high or long. It has been found that if the tensile strength is outside the above range, the tensile strength of the copper alloy material tends to decrease and not reach 620 MPa. In addition, a comparative evaluation of the copper alloy materials of Samples 1 and 27 revealed that the tensile strength of the copper alloy material tended to increase when the heating and holding temperature in the third heat treatment step was lowered. Further, by comparative evaluation of the copper alloy materials of Samples 1 and 27 with different heating and holding temperatures in the third heat treatment step, it was found that when the heating and holding temperature in the third heat treatment step was low and outside the above range, the copper alloy material It was found that the conductivity tended to decrease and not reach 40.0% IACS. Further, a comparative evaluation of the copper alloy materials of Samples 1 and 28 revealed that the electrical conductivity of the copper alloy material tends to increase when the heating and holding temperature in the third heat treatment step becomes high. In addition, a comparative evaluation of the copper alloy materials of Samples 1 and 27 revealed that the bending workability of the copper alloy material tends to deteriorate when the temperature of the third heat treatment step is outside the above range. did. In addition, a comparative evaluation of the copper alloy materials of Samples 1, 27, 28 and 29 revealed that the heating and holding conditions in the third heat treatment step had little effect on the residual smut of the copper alloy materials. Therefore, there is no residual smut, it has a tensile strength of 620 MPa or more, has an electrical conductivity of 40.0% IACS or more, and in addition, has good bending workability. The third heat treatment step of heating and holding the rolled material at a temperature of 250° C. or higher and 380° C. or higher for 4 hours or less to produce a copper alloy material is effective.

<Influence of Mn>
In order to evaluate the effect of Mn, a copper alloy material intentionally not containing Mn (Sample 1A) and a copper alloy material intentionally containing Mn (Samples 1B to 1F) were produced. The copper alloy materials of Samples 1A to 1F were substantially the same as those of Sample 1 shown in Table 1, except that the components were prepared in the melting and casting process so that the Mn content of the finally obtained copper alloy material was different. Through the manufacturing process, it was produced so as to have substantially the same thickness. Then, for the copper alloy materials of Samples 1A to 1F, the tensile strength at normal temperature (about 20 ° C.), the electrical conductivity and the bending workability were measured and confirmed in the same manner as in the case of Sample 1 shown in Table 1, and the residual smut was measured. Checked for presence. In addition, as described above, the elongation at break was measured in a high temperature environment of about 950° C. in accordance with JIS-G0567:2020, which defines the high temperature tensile test method.

Table 11 summarizes information such as the composition (additional elements), main manufacturing conditions, and mechanical properties of the copper alloy materials of Samples 1A to 1F (examples of the present invention). The rest of the samples 1A to 1F shown in Table 11 other than the additive elements may be interpreted as Cu and impurity elements, and the impurity elements (Ag, Pb, Ni, S, etc.) less than 0.01% are omitted. ing.

As shown in Table 11, the Mn content of Sample 1A, to which Mn is not intentionally added, is less than 0.001%. In addition, the Mn content of the copper alloy material to which Mn is intentionally added is about 0.001% for sample 1B, about 0.002% for sample 1C, about 0.006% for sample 1D, and about 0.006% for sample 1E. about 0.010% and sample 1F about 0.020%. Therefore, the Mn contents of the samples 1C to 1F are within the range of the Mn contents (0.002% or more and 0.025% or less) described above as the preferred copper alloy materials of the present invention.

The tensile strength, electrical conductivity, and bending workability of Samples 1A to 1F were evaluated under a normal temperature environment (about 20°C), and the presence or absence of residual smut was evaluated. As a result, as shown in Table 11, the tensile strength was All of them were 620 MPa or more and within the range of 650 to 670 MPa. When Mn is 0.002% or less (Samples 1A to 1C), the tensile strength is less than 660 MPa, and when Mn exceeds 0.002% (Samples 1D to 1F), it is 660 MPa or more. From this, the tensile strength is less likely to be substantially affected by the Mn content, and there is a high possibility that the tensile strength will be 620 MPa or more even if the Mn content is 0.002% or more and 0.025% or less. In addition, the electrical conductivity of samples 1A to 1F was all 40%IACS or higher and within the range of 46.0 to 47.2%IACS. From this, the electrical conductivity is less likely to be substantially affected by the Mn content, and there is a high possibility that the electrical conductivity will be 40% IACS or higher even if the Mn content is 0.002% or more and 0.025% or less. In addition, the bending workability of samples 1A to 1F was all "excellent". From this, the bending workability is not substantially affected by the Mn content, and it is highly likely that the bending property will be "excellent" even if the Mn content is 0.002% or more and 0.025% or less. In addition, the residual smut of Samples 1A to 1F was "absent". From this, the residual smut is less likely to be substantially affected by the Mn content, and there is a high possibility that the residual smut is "absent" even if the Mn content is 0.002% or more and 0.025% or less.

In addition, the elongation at break of samples 1A to 1F was evaluated in a high temperature environment (about 950°C). As a result, as shown in Table 11, the elongation at break of Samples 1A to 1F was generally 20% or more. Specifically, the elongation at break can be less than 20% when Mn is 0.001% or less (Samples 1A, 1B), and when Mn is 0.002% or more (Samples 1C-1F). It was found that the content definitely exceeds 20% and becomes 30% or more when Mn is 0.006% or more (Samples 1D to 1F). Further, the elongation at break reaches a maximum of 37.0% when Mn is 0.010% (Sample 1E), and decreases to 32.0% when Mn is 0.020% (Sample 1F). I understand. From this, the elongation at break is easily affected by the Mn content, and the Mn content of 0.002% or more and 0.025% or less reliably exceeds 20%, and the Mn content of 0.005% or more and 0.020% or less is likely to be 30% or more due to the content of

As described above, there is no residual smut, it has a tensile strength of 620 MPa or more in a normal temperature environment (about 20 ° C.), has an electrical conductivity of 40.0% IACS or more, and in addition, has good bending workability. In addition, from the viewpoint of having a breaking elongation of more than 20% in a high temperature environment (about 950 ° C.), practically, Fe, P, Zn and Sn are contained in the above range, and Mn is contained in the above range. A copper alloy material that

Next, an attempt was made to calculate the MI value based on the Fe, P, Sn and Mn contents (measured values) shown in Table 11. As described above, the MI value is a value obtained by (Mn content+total content of impurity elements)/(Fe content+P content+Sn content)×100. The total content of Fe, P and Sn is 2.82%. For example, when the total content of impurity elements is 0.001%, based on the measured values shown in Table 11, the increase in Mn content from 0% (Sample 1A) to 0.020% (Sample 1F) is proportional to It can be confirmed that the MI value increases from 0.04 (Sample 1A) to 0.74 (Sample 1F). However, in Samples 1A to 1F, the content of some impurity elements is less than 0.01%, but it is not realistic to actually measure all the impurity elements, and the exact value of the total content of impurity elements is is unknown. Therefore, an attempt was made to predict the relationship between the Mn content, the MI value, and the elongation at break based on the measured values shown in Table 11, assuming the total content of impurity elements.

Specifically, the total content of impurity elements is set to 0.010% (low purity), 0.005% (ordinary purity), and 0.001% ( high purity), the Mn content (measured value) and the MI value (conditionally calculated value) based on the measured value shown in Table 11 A first model was derived, and further, the MI value A second model was derived to show the relationship between (conditional calculated value) and elongation at break (actual value). A first model was then used to predict a range of MI values corresponding to a range of Mn contents, and a second model was used to predict a range of elongation at break corresponding to a range of MI values. The first model is a graph (scatter diagram) of the Mn content (actual value) and the MI value (conditionally calculated value) using general-purpose spreadsheet software (Microsoft Excel), considering practicality and ease. ) was created, and a linear (first-order) approximation formula was obtained and used as a regression model.

In the first model, the Mn content (set value) is the independent variable x, and the MI value (predicted value) is the first dependent variable p. The prediction interval is 0.000≦x≦0.030. Similarly, the second model was used as a regression model by creating a graph (scatter diagram) of MI values (calculated values with conditions) and elongation at break (actual values), obtaining a multinomial (quadratic) approximation formula. In the second model, the MI value (predicted value) of the first dependent variable p of the first model is the independent variable, and the elongation at break (predicted value) is the second dependent variable y. The reliability of the first model and the second model is unconditionally “reliable” if the coefficient of determination (R ² ) is 0.7 or more (R ² ≤ 1) with reference to the way of thinking in the field of machine learning. I decided.

Tables 12 and 13 show the total impurity element content of 0.010% (low purity), 0.005% (ordinary purity) and 0.001% (high purity) based on the measured values shown in Table 11. 3 shows the prediction results of the Mn content (set value), MI value (predicted value), and elongation at break (predicted value) under the following three conditions. In addition, when S, which has a particularly large effect on rolling workability, etc., is the main impurity element, the S content of general manufacturing raw materials is considered to be about 0.001% to 0.005%, and actual measurement is not possible. From the viewpoint of simplicity and high practicality, the total content of impurity elements can be selectively set and predicted from 0.001% to 0.005%. Further, when the impurity elements are mainly Ag, Pb, Ni and S, the total content of Ag, Pb, Ni and S can be set as the total content of the impurity elements for prediction.

As shown in Table 12, when the total content of impurity elements is 0.010% (low purity) with respect to the total content of Fe, P, and Sn (2.82%), the prediction result by the first model is For example, p is 0.37 when x is 0.000, p is 0.44 when x is 0.002, p is 1.00 when x is 0.018, and x is 0.00. 025, p became 1.25. The prediction result by the second model is, for example, y is 21.1 when p is 0.37, y is 25.5 when p is 0.44, and y is 1.00 when p is 1.00. 34.0 and y was 22.6 when p was 1.25. Both the R ² (0.9895) of the first model and the R ² (0.8590) of the second model are sufficiently larger than 0.7, which is a criterion of reliability. Therefore, the prediction results of the first model and the second model are less likely to be significantly affected by outliers, and therefore can be judged to be "reliable".

From this, it can be seen that even if x is 0.000, y will be 20 or more. It can also be seen that y decreases when x is greater than 0.018 and p is greater than 1.00. It can also be seen that p is 0.72 and x is 0.010 when y reaches its maximum (35.7). Therefore, if the Mn content is adjusted to 0.002% to 0.025%, the MI value is 0.44 to 1.25, which is 25.5% to 22.6% (maximum 35.7%). of breaking elongation can be obtained. Also, if the Mn content is adjusted to 0.010% to 0.018%, the MI value will be 0.72 to 1.00, and a larger elongation at break of 34.0% to 35.7% will be obtained. be able to. Therefore, when Mn is contained in a low-purity product, considering practicality and stability, the MI value is, for example, 0.45 or more (preferably 0.50 or more) and 1.1 or less (preferably, 1.0 or less, more preferably 0.9 or less).

As shown in Table 13, when the total content of impurity elements is 0.005% (medium purity) with respect to the total content of Fe, P, and Sn (2.82%), the prediction result by the first model is as follows. For example, p is 0.19 when x is 0.000, p is 0.26 when x is 0.002, p is 1.00 when x is 0.023, and x is 0.00. 025 p became 1.07. The prediction result by the second model is, for example, y is 20.8 when p is 0.19, y is 25.4 when p is 0.26, and y is 26.6, and y was 22.3 when p was 1.07. Both the R ² (0.9950) of the first model and the R ² (0.8712) of the second model are sufficiently larger than 0.7, which is a criterion of reliability. Therefore, the prediction results of the first model and the second model are less likely to be significantly affected by outliers, and therefore can be judged to be "reliable".

From this, it can be seen that even if x is 0.000, y will be 20 or more. It can also be seen that y decreases when x is greater than 0.010 and p is greater than 0.54. It can also be seen that p is 0.54 and x is 0.010 when y is at its maximum (36.0). Therefore, if the Mn content is adjusted to 0.002% to 0.025%, the MI value is 0.26 to 1.07, which is 25.4% to 22.3% (maximum 36.0%). of breaking elongation can be obtained. Also, if the Mn content is adjusted to 0.006% to 0.020%, the MI value will be 0.40 to 0.89, and a larger elongation at break of 31.8% to 36.0% will be obtained. be able to. Therefore, when Mn is contained in a product of ordinary purity, considering practicality and stability, the MI value is, for example, 0.30 or more (preferably 0.35 or more) and 1.1 or less (preferably, 1.0 or less, more preferably 0.9 or less).

As shown in Table 14, when the total content of impurity elements is 0.001% with respect to the total content of Fe, P, and Sn (2.82%), the prediction result by the first model is, for example, p is 0.04 when x is 0.000, p is 0.05 when x is 0.0003, p is 0.11 when x is 0.002, and p is 0.025 when x is 0.025. p was 1.00 when x was 0.93 and x was 0.027. Then, the prediction result by the second model is, for example, y is 20.5 when p is 0.04, y is 21.2 when p is 0.05, and y is 25.3, y was 22.0 when p was 0.93, and y was 16.4 when p was 1.00. Both the R ² (0.9980) of the first model and the R ² (0.8808) of the second model are sufficiently larger than 0.7, which is a criterion of reliability. Therefore, the prediction results of the first model and the second model are less likely to be significantly affected by outliers, and therefore can be judged to be "reliable".

From this, it can be seen that even if x is 0.000, y will be 20 or more. Also, it can be seen that y is less than 20 when x is 0.027 or more. It can also be seen that y decreases when x is greater than 0.010 and p is greater than 0.39. It can also be seen that p is 0.39 and x is 0.010 when y is at its maximum (36.3). Therefore, if the Mn content is adjusted to 0.002% to 0.025%, the MI value is 0.11 to 0.93, which is 25.3 to 22.0% (maximum 36.3%). Elongation at break can be obtained. Also, if the Mn content is adjusted to 0.006% to 0.020%, the MI value will be 0.25 to 0.75, and a larger elongation at break of 31.8% to 36.3% will be obtained. be able to. Therefore, when Mn is contained in a high-purity product, considering practicality and stability, the MI value is, for example, 0.15 or more (preferably 0.20 or more) and 0.9 or less (preferably, 0.85 or less, more preferably 0.80 or less).

As described above, the content of the additive elements (Fe, P, Zn and Sn) constituting the copper alloy structure of the copper alloy material is controlled within a specific range, and in the manufacturing process of the copper alloy material shown in FIG. By controlling the manufacturing conditions of the heat treatment process, the second cold rolling process, the second heat treatment process, the third cold rolling process and the third heat treatment process within a specific range, Cu-Fe-Zn-P such as C1940 It has been confirmed that a copper alloy material can be obtained that has almost the same tensile strength and electrical conductivity as Cu--Ni--Si-based copper alloy materials such as C7025, without the problem of residual smut, as with C7025-based copper alloy materials. Ta. Further, it was confirmed that a copper alloy material having good bending workability can be obtained by more appropriately controlling the content of the additive element and the manufacturing conditions. In addition, by adding Mn together with the above four additive elements and appropriately controlling the contents of the four additive elements and Mn, the elongation at break at high temperatures is improved, and the rolling processability is improved. It was confirmed that a copper alloy material that is resistant to cracking during hot rolling can be obtained.

Claims

In terms of the content in mass %, the essential elements are 1.6% or more and 2.6% or less of Fe, 0.01% or more and 0.3% or less of P, and 0.01% or more and 0.3% containing the following Zn and 0.3% or more and 0.8% or less of Sn, the balance being Cu and impurity elements,
A copper alloy material having a tensile strength of 620 MPa or more and an electrical conductivity of 40.0% IACS or more in a temperature environment of 20°C.
The copper alloy material according to claim 1, which contains 0.01% or more and 0.20% or less of P in terms of mass% content.
The content is expressed in mass %, and contains, as essential elements, Fe, P, Zn, and Sn, and 0.002% or more and 0.025% or less of Mn, and the balance is Cu and impurities. made up of elements,
The copper alloy material according to claim 1 or 2, which has an elongation at break exceeding 20% in a temperature environment of 950°C.
Claim 3, wherein the content in mass% is 1.1 or less, which is obtained by (Mn content + total impurity element content)/(Fe content + P content + Sn content) x 100. A copper alloy material as described.
In terms of the content in mass %, the essential elements are 1.6% or more and 2.6% or less of Fe, 0.01% or more and 0.3% or less of P, and 0.01% or more and 0.3% a melting and casting step of producing a copper alloy casting material containing the following Zn and 0.3% or more and 0.8% or less of Sn, the balance being Cu and impurity elements;
A hot rolling step of performing hot rolling using the copper alloy cast material to produce a hot rolled material;
A first cold-rolling step of cold-rolling the hot-rolled material to produce a first cold-rolled material;
A first heat treatment step of heating and holding the first cold rolled material at a temperature of 500 ° C. or more and 600 ° C. or less for 4 hours or less to produce a first heat treated material;
A second cold rolling step of cold rolling at a rolling reduction rate of 20% or more and 90% or less using the first heat treated material to produce a second cold rolled material;
a second heat treatment step of heating and holding the second cold-rolled material at a temperature of 380° C. or more and 480° C. or less for 1 hour or more and 12 hours or less to produce a second heat treated material;
A third cold rolling step of cold rolling at a rolling reduction rate of 60% or more and 80% or less using the second heat treated material to produce a third cold rolled material;
a third heat treatment step of heating and holding the third cold-rolled material at a temperature of 250° C. or higher and 380° C. or higher for 4 hours or less to produce a copper alloy material;
The melting and casting process, the hot rolling process, the first cold rolling process, the first heat treatment process, the second cold rolling process, the second heat treatment process, the third cold rolling process, and the A copper alloy material having a tensile strength of 620 MPa or more and an electrical conductivity of 40.0% IACS or more in a temperature environment of 20° C. by performing the third heat treatment step in order. How the material is made.
The method for producing a copper alloy material according to claim 5, wherein the copper alloy material contains 0.01% or more and 0.20% or less of P in terms of mass% content.
The content is expressed in mass %, and contains, as essential elements, Fe, P, Zn, and Sn, and 0.002% or more and 0.025% or less of Mn, and the balance is Cu and impurities. A melting and casting step for producing a copper alloy cast material made of elements, followed by the hot rolling step, the first cold rolling step, the first heat treatment step, the second cold rolling step, and the second By performing the heat treatment step, the third cold rolling step, and the third heat treatment step in this order,
The method for producing a copper alloy material according to claim 5 or 6, wherein the copper alloy material having a breaking elongation exceeding 20% is produced in a temperature environment of 950°C.
The content in mass% is (Mn content + total content of impurity elements) / (Fe content + P content + Sn content) x 100, and the value is 0.05 or more and 1.0 or less. 8. The method for producing a copper alloy material according to claim 7, wherein the step of melting and casting produces a copper alloy cast material.