KR20080007403A - Copper alloy, copper alloy plate, and process for producing the same - Google Patents

Abstract

This invention provides a copper alloy having excellent stress relaxation resistance, comprising Ni: 0.1 to 3.0% (% by mass; the same shall apply hereinafter), Sn: 0.01 to 3.0%, and P: 0.01 to 0.3% with the balance consisting of copper and unavoidable impurities, characterized in that the content of Ni in an extraction residue after extraction separation on a filter having an opening size of 0.1 mum by an extraction residue method is not more than 40% in terms of the proportion to the content of Ni in the copper alloy. In the extraction residue method, 10 g of the copper alloy is immersed in 300 ml of a methanol solution having an ammonium acetate concentration of 10% by mass. This copper alloy is used as an anode. On the other hand, platinum is used as a cathode. Galvanostatic electrolysis is carried out at a current density of 10 mA/cm^2. A solution containing this copper alloy dissolved therein is subjected to suction filtration by a polycarbonate membrane filter having an opening size of 0.1 mum, and the insolubles as the residue are separated and extracted on the filter. The content of Ni in the extraction residue is determined by dissolving the insolubles as the residue on the filter in a solution composed of a mixture of aqua regia and water at a ratio of 1 : 1, and then analyzing the solution by ICP emission spectrometry.

Description

Copper alloy, copper alloy plate, and manufacturing method thereof {COPPER ALLOY, COPPER ALLOY PLATE, AND PROCESS FOR PRODUCING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is excellent in bending workability, shear punching resistance, and stress relaxation resistance, and particularly relates to a copper alloy, a copper alloy plate, and a manufacturing method thereof suitable for an automobile terminal / connector.

BACKGROUND ART In recent years, connecting parts such as automotive terminals and connectors have been required to have low-cost performance capable of ensuring reliability in a high-temperature environment such as an engine room. One of the most important characteristics in reliability under this high temperature environment is the holding characteristic of contact fitting force and so-called stress relaxation resistance. In other words, when a normal displacement is applied to a spring-like part made of a copper alloy, for example, when a tab of a male terminal is fitted at a spring-shaped contact of a female terminal, these connecting parts are the same as the engine room. When maintained in a high temperature environment, the contact sensitivity decreases with time, and the stress relaxation resistance is a resistance thereto.

As a copper alloy excellent in the stress relaxation resistance, Cu-Ni-Si type alloy, Cu-Ti type alloy, Cu-Be type alloy etc. are widely known conventionally. Since all of them contain strong oxidizing elements (Si, Ti, Be, etc.), they cannot be dissolved in a large-scale melting furnace with wide openings in the atmosphere, and high costs cannot be avoided in terms of productivity.

On the other hand, a Cu-Ni-Sn-P-based alloy having a relatively small amount of added element can be so-called shaft furnace ingot, and its low productivity can be significantly reduced. Also in this Cu-Ni-Sn-P alloy, various measures for improving the stress relaxation resistance have been proposed in the past. Moreover, it is a very promising alloy system that can exhibit stress relaxation characteristics up to the level equivalent to that of Cu-Be alloys depending on the production method and the amount of added elements.

For example, Patent Document 1 below discloses a method for producing a copper base alloy for connectors having excellent stress relaxation resistance. This manufacturing method is to uniformly and finely disperse the Ni-P intermetallic compound in the matrix of the Cu-Ni-Sn-P-based alloy to improve electrical conductivity and to improve stress relaxation resistance, etc. According to this document, in order to obtain desired characteristics, it is necessary to strictly control the starting and ending temperatures of the hot rolling, the cooling rate thereof, and the heat treatment temperature and time for 5 to 720 minutes which are carried out during the subsequent cold rolling step. have.

In addition, Patent Documents 2 and 3 below disclose Cu-Ni-Sn-P alloys excellent in stress relaxation resistance and a method for producing the same, and have a solid solution copper alloy in which P content is reduced as much as possible to suppress the precipitation of Ni-P compounds. Is disclosed. According to this, there is an advantage that it can be manufactured by the annealing heat treatment of extremely short time, without requiring an advanced heat treatment technique.

Patent Document 1: Japanese Patent Publication No. 2844120

Patent Document 2: Japanese Unexamined Patent Publication No. 1999-293367

Patent Document 3: Japanese Unexamined Patent Publication No. 2002-294368

Disclosure of the Invention

Problems to be Solved by the Invention

Standard JASO-C400 of the Japan Society of Automotive Engineers, Inc. specifies that the stress relaxation rate after holding at 150 ° C. for 1000 hours is 15% or less in terms of stress relaxation resistance. 1 (a) and (b) show a test apparatus of stress relaxation resistance. Using this test apparatus, one end of the test piece 1 cut out of a thin paper shape is fixed to the rigid test bench 2, and the other end is lifted up by a cantilever beam method (the size of the warping d), After keeping this at predetermined temperature and time, it removes at room temperature and calculates | requires the magnitude (permanent deformation) of the curvature after taking out as (delta). The stress relaxation ratio RS is represented by RS = (δ / d) × 100.

There is anisotropy in the stress relaxation ratio of a copper alloy plate, and it becomes a different value according to which direction the longitudinal direction of a test piece faces with respect to the rolling direction of a copper alloy plate. In general, the stress relaxation rate is smaller in the parallel direction with respect to the rolling direction than in the right angle direction. However, the JASO standard does not specify such a direction, and therefore, it is conventionally required that a stress relaxation rate of 15% or less is achieved in either of the direction parallel or perpendicular to the rolling direction. However, in recent years, it is said that a copper alloy plate preferably has high stress relaxation resistance in the direction perpendicular to the rolling direction.

The cross-sectional structure of a typical box-shaped connector (female terminal 3) is shown in FIG. In FIG. 2, when the pressing piece 5 is laterally supported by the upper holder part 4, and the male terminal 6 is inserted, the pressing piece 5 elastically deforms and the male terminal is caused by the reaction force. (6) is fixed. In addition, in FIG. 2, 7 is a wire connection part, 8 is a fixing tongue. Here, when manufacturing the female terminal 3 by press-processing a copper alloy plate, plate removal is carried out so that the longitudinal direction (the longitudinal direction of the press piece 5) of the female terminal 3 may face a perpendicular direction with respect to a rolling direction. do. In the pressing piece 5, particularly high stress relaxation resistance is required for bending (elastic deformation) in the longitudinal direction of the pressing piece 5. Therefore, the copper alloy plate is required to have high stress relaxation resistance in a direction perpendicular to the rolling direction.

On the other hand, in the solid solution copper alloy disclosed in Patent Documents 2 and 3, although high stress relaxation resistance of 15% or less of stress relaxation rate is almost achieved in the parallel direction to the rolling direction, it is still achieved in the right angle direction. Not.

Therefore, the high stress relaxation resistance of 15% or less of a stress relaxation rate is calculated | required from the user side about this type of solid solution type copper alloy in a direction perpendicular to a rolling direction rather than a parallel direction with respect to a rolling direction.

In addition, the generation energy of the Ni-P intermetallic compound is very low and easily coarsened in the heat treatment during the copper alloy manufacturing process, supporting the accuracy of the terminal shape while exhibiting the level of stress relaxation characteristics required by current automotive technology. Defects such as deterioration of the bendability and enlargement of the punching burrs that wear the terminal punching dies have occurred.

Here, when the cross-sectional structure of a typical box-shaped connector (female terminal 3) is seen, as shown in FIG. 2, when the male terminal 6 is inserted in the side-side support of the upper holder part 4, the press piece 5 ) Elastically deforms, and the male terminal 6 is fixed by the reaction force. 2, 7 is a wire connection part, 8 is a fixing tongue. When manufacturing such a connector from a copper alloy sheet, bending workability and shear punching processing are frequently used. In order to manufacture a compact and precise connector, excellent bending workability is necessary both in a parallel direction and a perpendicular direction with respect to the rolling direction. In the case of shear punching, when a large burr is generated, the burr is inserted in the bending part and precision bending is hindered. When the burr is generated at the wire connection part, the wire is cut during bending, and the burr is generated by punching. Promote the wear of the mold. Therefore, excellent bending workability and shear punching property are requested | required of this kind of copper alloy plate.

On the other hand, it cannot be said that the bending workability and shear punching property of the conventional Cu-Ni-Sn-based solid solution copper alloy are still sufficient.

In view of these points, it is an object of the present invention to achieve high stress relaxation resistance of 15% or less of stress relaxation ratio in a direction perpendicular to the rolling direction in Cu-Ni-Sn-P alloy.

In addition, the present invention provides a Cu-Ni-Sn-based solid solution copper alloy, which has excellent bending formability at right angles and perpendicular to the rolling direction and at the same time obtains a copper alloy sheet for electrical connection parts having excellent shear punching property. For the purpose of

Means to solve the problem

In order to achieve this object, the gist of the copper alloy excellent in the stress relaxation resistance of the present invention contains Ni: 0.1 to 3.0%, Sn: 0.01 to 3.0%, P: 0.01 to 0.3%, respectively, The copper alloy which consists of copper and an unavoidable impurity WHEREIN: The following Ni amount in the extraction residue extracted and isolate | separated on the filter of 0.1 micrometer of pore sizes by the following extraction residue method is 40% or less as a ratio with respect to Ni content in the said copper alloy. Shall be.

In the extraction residue method, 10 g of the copper alloy is immersed in 300 ml of a methanol solution having a concentration of 10% by mass of ammonium acetate, the copper alloy is used as an anode, and platinum is used as a cathode. Constant current electrolysis is carried out at ² , and the said solution which melt | dissolved this copper alloy is suction-filtered by the polycarbonate membrane filter of 0.1 micrometer of pore sizes, and it is supposed to isolate | extract and extract the undissolved matter residue on this filter.

In addition, the said amount of Ni in the said extraction residue shall be calculated | required by analyzing by ICP emission spectroscopy, after melt | dissolving the undissolved residue on the said filter with the solution which mixed aqua regia and water in 1 to 1 ratio.

Moreover, the summary of the manufacturing method of the copper alloy plate excellent in the stress relaxation resistance of this invention for achieving the said objective is a method of manufacturing the copper alloy plate of the preferable aspect mentioned later-mentioned later, casting of a copper alloy, hot When obtaining a copper alloy sheet by rolling, cold rolling, or annealing, the time required from the completion of addition of the alloying elements in the copper alloy melting furnace to the start of casting is set within 1200 seconds, and the ingot is heated from the furnace of the ingot. The time required from extraction to completion of hot rolling is made into 1200 second or less.

Moreover, the copper alloy plate for electrical connection components which concerns on this invention contains Ni: 0.4-1.6%, Sn: 0.4-1.6%, P: 0.027-0.15%, Fe: 0.0005-0.15%, and Ni content and P Ni / P which is ratio of content is less than 15, it has the composition which remainder consists essentially of Cu and an impurity, and the structure in which the precipitate was disperse | distributed in the copper alloy mother phase, The said precipitate is 60 nm or less in diameter, and is diameter within the visual field of 500 nm x 500 nm. It is characterized by 20 or more thing of 5 nm or more and 60 nm or less being observed.

The composition of the said copper alloy plate is Zn: 1% or less, Mn: 0.1% or less, Si: 0.1% or less, Mg: 0.3% or less, any one or more types, and / or Cr, Co, Ag, In, Be, Al, Ti, V, Zr, Mo, Hf, Ta, B may be included in a total amount of 0.1% or less.

Effects of the Invention

According to the present invention, in the Cu-Ni-Sn-P-based copper alloy, high stress relaxation resistance of 15% or less of stress relaxation ratio can be achieved in a direction perpendicular to the rolling direction. Moreover, it is excellent in electrical conductivity (about 30% IACS or more), strength (about 480 MPa or more), etc. which are excellent in bending workability, and can obtain the copper alloy which has the outstanding characteristic for other terminals and connectors.

MEANS TO SOLVE THE PROBLEM In the solid solution type copper alloy which suppressed precipitation of the said conventional Ni-P compound, although the high stress relaxation resistance of 15% or less of stress relaxation rate is almost achieved in parallel with a rolling direction, The reasons for not yet achieved in the perpendicular direction were examined.

As a result, when suppressing coarse Ni oxide, crystallization, and precipitate of more than a certain size, it was found that high stress relaxation resistance of 15% or less of stress relaxation ratio was achieved in the direction perpendicular to the rolling direction.

That is, coarse Ni oxide, crystallized substance, and precipitate of this fixed size or more correspond to the amount of Ni in the extraction residue extracted and separated on the filter of 0.1 micrometer of pore size in the said summary of this invention. When the amount of Ni in this extraction residue is suppressed to 40% or less in the ratio with respect to Ni content in the said copper alloy like the said summary of this invention, the high stress relaxation resistance of 15% or less of a stress relaxation rate will be in the rolling direction. Is achieved in a direction perpendicular to. In addition, bending workability, electrical conductivity and strength may be excellent at the same time.

In this way, if Ni compounds (Ni products) such as coarse Ni oxides, crystals, and precipitates of more than 0.1 μm in coarse size are suppressed, on the other hand, fine Ni compounds of 0.1 μm or less (nano level or less And a high capacity of Ni. In addition, Ni cluster means the atomic group before crystallization in an atomic structure level.

As described in Patent Document 1, only the uniform fine dispersion of the Ni-P intermetallic compound in the Cu-Ni-Sn-P-based alloy matrix does not improve the stress relaxation resistance in the direction perpendicular to the rolling direction. It is necessary to ensure the amount of the fine Ni compound and the high capacity of Ni or less. However, these fine Ni compounds of 0.1 µm or less and the high capacity of Ni cannot be directly measured.

On the other hand, in this invention, it is characteristic to ensure the quantity of these fine Ni compounds of 0.1 micrometers or less and high capacity of Ni indirectly by suppressing the coarse Ni compound exceeding 0.1 micrometer.

In the present invention, in order to suppress the coarse Ni compound exceeding 0.1 μm and to secure a fine Ni compound amount of 0.1 μm or less and a high capacity of Ni, production conditions different from those of the conventional method are required. That is, according to the gist of the manufacturing method of the copper alloy plate of the present invention, when the copper alloy plate is obtained by casting, hot rolling, cold rolling, or annealing the copper alloy, casting is completed from the addition of alloying elements in the copper alloy melting furnace. It is necessary to shorten the time until the start and further shorten the time from the extraction of the ingot to the heating furnace of the ingot until the end of the hot rolling.

In a general manufacturing process of this kind of copper alloy plate, these required time tends to be prolonged for a long time. For this reason, most of the added Ni content becomes oxides, crystals, and coarse precipitates generated from the cracking of the ingot to the end of the hot rolling, and is produced in accordance with the added Ni content. The amount of Ni compound and the solid solution of Ni are surprisingly small.

Usually, in the general manufacturing process of this kind of copper alloy plate, a final (product) board is obtained by hot rolling and repeating cold rolling and annealing, and mainly Ni coldness conditions and annealing conditions are fine Ni below 0.1 micrometer. The amount of the compound and the high dose of Ni are controlled. In that case, diffusion of alloying elements, such as Ni, into the suitably dispersed intermetallic compound stabilizes high capacity | capacitances, such as Ni, and precipitation amount of a microproduct, and tries to control mechanical characteristics, such as an intensity level, by this.

However, in these general manufacturing processes, since the amount of fine Ni compounds of 0.1 µm or less or the absolute amount of high capacity of Ni is reduced in the shearing step as described above, the cold rolling conditions after the hot rolling and the annealing conditions are used. Even if many products were to be precipitated, it was difficult to improve the strength and stress relaxation resistance due to a lack of a fine Ni compound of 0.1 µm or less and a high amount of Ni.

In addition, when the coarse oxides, crystals, and precipitates (Ni compounds) are large, the fine products precipitated in the cold rolling and annealing processes are trapped in the coarse products, and the fine products existing independently in the matrix become less and less. Lose. For this reason, in the above general manufacturing method, sufficient strength and excellent stress relaxation resistance could not be obtained as compared with a large amount of Ni added.

On the other hand, in the present invention, by suppressing the coarse Ni compound exceeding 0.1 µm, the amount of fine Ni compound and the high capacity of Ni required (useful) of 0.1 µm or less can be ensured. As a result, high stress relaxation resistance of 15% or less of stress relaxation ratio is achieved in the direction perpendicular to the rolling direction. In addition, bending workability, conductivity and strength may be excellent at the same time.

Moreover, according to this invention, in the solid copper alloy of Cu-Ni-Sn type | mold, it has the excellent bending workability in a perpendicular | vertical direction and a perpendicular direction with respect to a rolling direction, and simultaneously has an excellent shear punching property, the copper alloy plate for electrical connection parts Can be obtained.

1 is a cross-sectional view illustrating a stress relaxation test of a copper alloy plate.

2: is a front view (a) and sectional drawing (b) which show the structure of a box-shaped connector (female terminal).

Explanation of the sign

1: test piece

3: female terminal

Best Mode for Carrying Out the Invention

Embodiment 1

(Copper Alloy Component Composition)

First, the component composition of the copper alloy of the present invention will be described below. In the present invention, on the premise of the component composition of the copper alloy, as described above, it is possible to form a Cu-Ni-Sn-P-based alloy capable of ingot into a shaft and greatly reducing the cost due to its high productivity.

And in order to make high stress relaxation resistance of a perpendicular | vertical direction to a rolling direction required at the same time as connection parts, such as an automotive terminal and connector, and also to bend workability, electrical conductivity, and strength excellently, Ni: 0.1-3.0 %, Sn: 0.01-3.0%, P: 0.01-0.3%, respectively, It is set as the copper alloy which consists of remainder copper and an unavoidable impurity. In addition, all% display of each element content is the meaning of the mass%. Below, the alloying element of a copper alloy is explained about the addition reason or suppression reason.

(Ni)

Ni is an element necessary for forming fine precipitates with P to improve strength and stress relaxation resistance. If the content is less than 0.1%, the optimum amount of the Ni compound and the absolute amount of the high capacity of Ni may be insufficient, even by the optimum production method of the present invention. For this reason, in order to exhibit the effect of Ni effectively, it is necessary to contain 0.1% or more.

However, when it contains excessively more than 3.0%, compounds, such as Ni oxide, crystallization, and a precipitate, will coarsen, or a coarse Ni compound will increase and the amount of Ni in the said extraction residue will be Ni in a copper alloy. It cannot be 40% or less as a ratio with respect to content. As a result, the amount of fine Ni compounds and the solid solution amount of Ni of 0.1 micrometer or less fall. Moreover, since these coarse Ni compounds are a starting point of breakdown, not only strength and stress relaxation resistance but also bending workability fall. Therefore, content of Ni is made into 0.1 to 3.0% of range. Preferably, it is 0.3 to 2.0% of range.

(Sn)

Sn is dissolved in a copper alloy to improve strength. In addition, Sn-based precipitates suppress softening due to recrystallization during annealing. However, in the copper alloy according to the present invention, in order to actively generate Sn-based precipitates, annealing at higher temperatures is required. However, if the Sn content is less than 0.1%, softening due to recrystallization during annealing cannot be suppressed. The strength is lowered. Therefore, when the Sn content is less than 0.1%, it is necessary to increase the strength by increasing the reduction ratio of the final cold rolling after annealing. In this case, electrical conductivity and stress relaxation resistance slightly deteriorate. However, if the Sn content is less than 0.01%, the amount of Sn is too small and the strength is too low even if the reduction rate of the final cold rolling after annealing is increased, so that these characteristic balances do not reach a desired level. On the other hand, if it exceeds 3.0%, the conductivity is lowered and 30% IACS or more cannot be achieved. Therefore, the content of Sn is in the range of 0.01 to 3.0%, preferably in the range of 0.1 to 2.0%, and more preferably in the range of 0.3 to 2.0%.

(P)

P is an element necessary for forming fine precipitates with Ni and improving strength and stress relaxation resistance. When it contains less than 0.01%, since P-type fine precipitate particle runs short, containing 0.01% or more is required. However, when it contains excessively more than 0.3%, Ni-P intermetallic compound precipitation particle | grains will coarsen, and not only strength and stress relaxation resistance, but also hot workability will fall. Therefore, content of P is made into 0.01 to 0.3% of range. Preferably, it is in the range of 0.02 to 0.2%.

(Fe, Zn, Mn, Si, Mg)

Fe, Zn, Mn, Si, Mg are easy to mix from dissolution raw materials, such as scrap. Although these elements have respective containing effects, they generally lower the electrical conductivity. In addition, when content increases, it becomes difficult to ingot in a shaft furnace. Therefore, in the case where a conductivity of 30% IACS or more is obtained, Fe: 0.5% or less, Zn: 1% or less, Mn: 0.1% or less, Si: 0.1% or less, and Mg: 0.3% or less, respectively. In other words, in this invention, containing below these upper limit is permissible.

Fe, like Sn, increases the recrystallization temperature of the copper alloy. However, if it exceeds 0.5%, the conductivity is lowered and 30% IACS cannot be achieved. Preferably, you may be 0.3% or less.

Zn prevents peeling of tin plating. However, if it exceeds 1%, the conductivity is lowered and 30% IACS cannot be achieved. In addition, in the case of coarsening in a shaft furnace, 0.05% or less is preferable. And if it is a temperature range (about 150-180 degreeC) used as an automotive terminal, even if it contains 0.05% or less, there exists an effect which can prevent peeling of tin plating.

Mn and Si have an effect as a deoxidizer. However, if it exceeds 0.1%, the conductivity is lowered and 30% IACS cannot be achieved. In addition, in the case of ingot in the shaft furnace, it is more preferable that the Mn is 0.001% or less and Si: 0.002% or less, respectively.

Mg has an effect of improving the stress relaxation resistance. However, if it exceeds 0.3%, the conductivity is lowered and 30% IACS cannot be achieved. Moreover, in the case of ingot in a shaft furnace, 0.001% or less is preferable.

(Ca, Zr, Ag, Cr, Cd, Be, Ti, Co, Au, Pt)

The copper alloy of the present invention also allows Ca, Zr, Ag, Cr, Cd, Be, Ti, Co, Au, and Pt to contain 1.0% or less in the total of these elements. Although these elements have an effect of preventing coarsening of crystal grains, when the total of these elements exceeds 1.0%, the conductivity decreases and 30% IACS cannot be achieved. In addition, it becomes difficult to ingot in the shaft furnace.

In addition, Hf, Th, Li, Na, K, Sr, Pd, W, S, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, Bi, Te, B Mischmetal is an impurity and is limited to 0.1% or less in total of these elements.

Extraction Residue Regulation

In the present invention, as described above, coarse Ni oxides, crystals, and precipitates (Ni compounds) exceeding a predetermined size of 0.1 μm are suppressed, and high stress relaxation resistance of 15% or less of stress relaxation rate is applied to the rolling direction. To achieve at right angles.

In the present invention, the coarse Ni compound amount of the fixed size or more is defined as the Ni amount in the extraction residue extracted and separated on the filter having a pore size of 0.1 µm. And the amount of Ni (coarse Ni compound amount) in this extraction residue is prescribed | regulated to 40% or less by the ratio with respect to Ni content in the said copper alloy.

Thus, suppressing the coarse Ni compound amount more than a predetermined size produces the effect of suppressing these coarse Ni compounds, and ensuring the amount of fine Ni compounds of 0.1 µm or less and high capacity of Ni. As a result, high stress relaxation resistance of 15% or less of stress relaxation ratio is achieved in the direction perpendicular to the rolling direction. In addition, bending workability, electrical conductivity and strength may be excellent at the same time.

When the ratio with respect to Ni content in the said copper alloy of Ni amount in the said extraction residue exceeds 40%, the said coarse compound amount increases. As a result, the amount of the fine Ni compound and the solid solution of Ni of 0.1 µm or less are insufficient. For this reason, while the stress relaxation resistance and intensity | strength of a perpendicular | vertical direction are falling with respect to a rolling direction, since the said coarse compound becomes a starting point of destruction, bending workability also falls.

(Extract residue)

The extraction residue method defined by this invention prescribes specific measurement conditions in order to make a measurement reproducible. That is, 10 g of said copper alloy is immersed in 300 ml of methanol solution of 10 mass% ammonium acetate concentration, and this copper alloy is used as an anode, and platinum is used as a cathode, and constant current electrolysis is performed at 10 mA / cm <^2> of current density. . Thereby, the said solution which melt | dissolved this copper alloy is suction-filtered by the polycarbonate membrane filter of 0.1 micrometer of pore sizes, and it is supposed that the undissolved matter residue is separated and extracted on this filter. On the other hand, the pore size of 0.1 mu m is the pore size of the smallest filter in the present state.

In the solution which melt | dissolved the said copper alloy, Ni previously dissolved in the copper matrix melt | dissolves, and the coarse Ni compound exceeding 0.1 micrometer and the fine Ni compound of 0.1 micrometer or less disperse | distribute without melt | dissolving. For this reason, the undissolved matter residue separated and extracted on the filter of 0.1 micrometer of pore sizes becomes only coarse Ni compound exceeding 0.1 micrometer. On the other hand, Ni previously dissolved and fine Ni compounds of 0.1 µm or less pass through the filter together with the solution.

(Ni amount in extraction residue)

The amount of Ni in the separated and extracted residue is determined by analyzing the undissolved residue on the filter by a solution in which aqua regia and water are mixed at a ratio of 1 to 1, and then analyzed by ICP emission spectroscopy.

(Copper Alloy Manufacturing Method)

Next, the manufacturing method of the copper alloy of this invention is demonstrated below. The copper alloy of the present invention can be produced by a conventional method itself. In other words, the final (product) plate is obtained by repetition of casting, ingot roughing, cracking, hot rolling, and cold rolling and annealing of the molten copper alloy in which the component composition is adjusted. And control of mechanical characteristics, such as an intensity level, is also mainly performed by controlling precipitation of the fine product of 0.1 micrometer or less by cold rolling conditions and annealing conditions.

However, as an optimal manufacturing method for producing the copper alloy plate of the present invention, when the copper alloy plate is obtained by casting, hot rolling, cold rolling, or annealing of the copper alloy, from the completion of addition of the alloying element in the copper alloy melting furnace The required time until the start of casting is set to 1200 seconds or less, and the required time from extraction of the ingot to the end of hot rolling is set to 1200 seconds or less.

In this invention, in order to suppress the said coarse Ni compound exceeding 0.1 micrometer, and to ensure the amount of the fine Ni compound of 0.1 micrometer or less and high capacity of Ni, addition of the alloying element in a copper alloy melting furnace is completed in this way. The shortening time from the start of casting to the start of casting and the ingot extraction from the heating furnace of the ingot and the end of the hot rolling are required.

In the general manufacturing process of this kind of copper alloy plate, these time requirements are easy to prolong. For this reason, most of the added Ni content becomes coarse precipitates generated from the cracks of oxides, crystals and ingots during the melting and casting to the end of the hot rolling, and fine Ni of 0.1 µm or less to be produced according to the added Ni content. The amount of compound and the solid solution of Ni decrease.

Therefore, even if it is going to control the amount of the fine Ni compound of 0.1 micrometers or less and high capacity of Ni by the main cold rolling conditions and annealing conditions of the latter stage, the amount of fine Ni compounds of 0.1 micrometer or less and the absolute amount of high capacity of Ni in the process of the said front end It is getting less. In addition, when there are many said coarse Ni compounds, the fine product precipitated in the cold rolling and annealing process is trapped in this coarse product, and the fine product which exists independently in a matrix becomes less and less. For this reason, in the above general manufacturing method, sufficient strength and excellent stress relaxation resistance could not be obtained as compared with a large amount of Ni added.

For this reason, in this invention, in the said manufacturing process, a coarse Ni compound is suppressed more upstream. In other words, in order to suppress coarse Ni compounds, it is important to control the time from (1) completion of alloy element addition to the start of casting in the melting furnace, and (2) time management from the extraction of the ingot from the heating furnace to the end of hot rolling. do.

First, melt | dissolution and casting itself can be performed by normal methods, such as continuous casting and semicontinuous casting. However, in the time management from the completion of the alloy element addition in the melting furnace to the start of casting in the melting furnace of the above (1), casting is performed within 1200 seconds, preferably within 1100 seconds, from the completion of the element addition in the melting furnace, and then cooled and solidified. The speed is preferably at least 0.1 ° C / sec, preferably at least 0.2 ° C / sec.

Thereby, generation | occurrence | production, growth, and coarsening of the oxide and crystallization containing Ni can be suppressed, and these can be disperse | distributed finely. From the viewpoint of suppressing the production of the oxide containing Ni, it is more preferable to perform dissolution and casting in a vacuum dissolution and casting or in an atmosphere having a low oxygen partial pressure.

Conventionally, in order to dissolve a master alloy such as Cu-P containing an additive element and to disperse uniformly the solid solution in the molten additive element in a molten metal, re-analysis after the recommendation of the raw material is necessary. It took more than 1500 seconds. However, it has been found that when casting takes time, casting and coarsening of oxides containing Ni are promoted and the yield of additional elements is lowered.

In order to avoid formation and coarsening of the oxide containing Ni, in the copper alloy production of the present invention, the time required from the completion of the alloy element addition in the melting furnace to the start of casting as described above is preferably within 1200 seconds, preferably Shorten it to within 1100 seconds. Such a reduction in time until casting can be achieved by predicting the composition after the raw material recommendation based on past solvent performance, shortening the time required for reanalysis, and the like.

Next, in the time management from extracting the ingot from the heating furnace of (2) to the end of the hot rolling, the ingot taken out of the furnace after heating the ingot in the heating furnace takes time to wait until the start of hot rolling. However, in producing a copper alloy in which coarsening of the Ni compound of the present invention is suppressed, the time from the melting to the start of casting and the control of the cooling and solidification rate are controlled, and from the time when the ingot is extracted from the heating furnace to the end of the hot rolling. It is recommended to control the required (total elapsed) time of not more than 1200 seconds, preferably not more than 1100 seconds.

Conventionally, managing the time from the heating furnace extraction to the end of the hot rolling is not considered, and 1500 seconds is extended by the expansion of the hot rolling time due to the transportation from the heating furnace to the hot rolling line and the increase of the slab aimed at improving the productivity. It was common for over time to be spent. However, when time was taken in this way, it was found that Ni-based coarse precipitates precipitated therebetween, and Ni and P precipitated as crystals or oxides generated during dissolution and casting as nuclei. When these coarse precipitated particles increase, the amount of Ni residues excessively increases, so that the strength and the stress relaxation resistance decrease.

In order to avoid such a decrease in solid solution Ni and coarsening of the Ni compound, in the production of the alloy of the present invention, as described above, the total required time from the heating furnace extraction to the end of the hot rolling is managed within 1200 seconds. do. This time management can be achieved by quickly transporting the ingot from the furnace to the hot rolled line, avoiding the use of large slabs with a long hot rolling time, rather using small slabs.

Regarding hot rolling, a conventional method may be followed. The start temperature of the hot rolling may be about 600 to 1000 ° C, and the end temperature may be about 600 to 850 ° C. After hot rolling, it is cooled by water or by cooling.

Thereafter, cold rolling and annealing are performed to obtain a copper alloy sheet having a product sheet thickness. Annealing and cold rolling may be repeated according to the final (product) plate thickness. Cold rough rolling selects the processing rate so that a processing rate of about 30 to 80% is obtained in the final finish rolling. Intermediate recrystallization can be appropriately sandwiched during cold rough rolling.

The finish annealing to the copper alloy plate after cold rough rolling may be continuous annealing or batch annealing. In order to increase the amount of precipitation of the fine Ni-P intermetallic compound, however, the holding temperature is necessarily high at continuous annealing (short time), and at a low temperature at batch annealing (long time). Under the present circumstances, as a reference of processing temperature (actual temperature) and holding time, 500-800 degreeCx10 to 60 second is preferable at continuous annealing, and 300 to 600 degreeCx2 to 20 hours at batch annealing (long time). On the other hand, it is preferable to quench at a cooling rate of 10 degrees C / sec or more after this finishing annealing.

It is preferable to perform the strain removal removal or stabilization removal after final finishing cold rolling at a substance temperature of 250-450 degreeCx20-40 seconds. This is because the deformation introduced in the final finish rolling is eliminated, and there is no softening of the material and the decrease in strength is small.

Embodiment 2

Hereinafter, the copper alloy plate which concerns on Embodiment 2 of this invention is demonstrated. First, the composition of the copper alloy which concerns on Embodiment 2 of this invention is demonstrated.

Ni is an element that solidifies in the copper alloy to enhance stress relaxation resistance and improve strength. However, when it is 0.4% or less, the effect is ineffective, and when it exceeds 1.6%, P and the intermetallic compound which are added simultaneously are precipitated easily, solid solution Ni reduces, and stress relaxation resistance falls. Therefore, content is made into 0.4 to 1.6%. The range of 0.7 to 0.9% is more preferable.

Sn is an element which solid-solution in copper alloy brings about the strength improvement by work hardening. Moreover, in this alloy system, it is an element which also contributes to heat resistance. In the copper alloy sheet according to the present invention, in order to improve the bending workability and the shear punching property, it is necessary to perform finish annealing at a high temperature, but when the Sn content is less than 0.4%, the heat resistance is lowered and recrystallization softening in the finish annealing. Since is advanced, the temperature of the finish annealing cannot be raised sufficiently. On the other hand, when it exceeds 1.6%, electrical conductivity will fall and 30% IACS cannot be achieved in a copper alloy plate end product. Therefore, Sn content is made into 0.4 to 1.6%. The range of 0.6 to 1.3% is more preferable. On the other hand, by performing finish annealing at a high temperature, there is also an advantage that sufficient solid solution Ni necessary for improving stress relaxation resistance is obtained.

P is an element which expresses Ni-P precipitate during a manufacturing process and improves heat resistance at the time of finishing annealing. As a result, unwinding at a high temperature is possible, and bending workability and shear punching property are improved. However, if it is less than 0.027%, it becomes easy to combine with Ni which has a relatively large amount of addition compared to the amount of P added, and a firm Ni-P intermetallic compound is formed, while when P is added in excess of 0.15%, Ni-P metal The amount of precipitated hepatic compound is further increased, so that the Ni-P intermetallic compound is not re-used in the finish annealing, the bending workability and shearing workability are deteriorated, and sufficient solid solution Ni for improving the stress relaxation resistance is not obtained. Do not. Therefore, P content is made into 0.027 to 0.15%. More preferably, 0.05 to 0.08%.

In addition, the reason why the Ni / P ratio is less than 15 is that the Ni-P precipitates at the time of refining and recrystallization softening by Ni-P precipitates for re-stocking and dislocation fixation of Ni at high finishing annealing temperature This is to make it possible to disassemble and rebuild the product. When Ni / P ratio is 15 or more, heat resistance improvement is inadequate, and it is inevitably finished at a relatively low temperature, bending workability and shear punching property are not improved, and sufficient stress relaxation resistance is not obtained.

Fe is an element which suppresses the coarsening of recrystallized grain in annealing. By adding 0.0005% or more in the copper alloy, the copper alloy is heated to a high temperature in finishing annealing to sufficiently dissolve the additive element, and at the same time, coarsening of the recrystallized particles can be suppressed. However, if it exceeds 0.15%, the conductivity is lowered and about 30% IACS cannot be achieved.

The copper alloy of this invention can further add Zn, Mn, Mg, Si, and other elements as a subcomponent.

Zn may be added in an amount of 1% or less in order to prevent peeling of the tin plating. However, it is sufficient to add it at 0.05% or less in the temperature range (about 150-180 degreeC) used as an automotive terminal. In addition, 0.05% or less is preferable in case of ingot in a shaft furnace.

Mn and Si can be added 0.01% or less as a deoxidizer, respectively. However, 0.001% or less and 0.002% or less are preferable, respectively.

Mg has the effect | action which improves a stress relaxation resistance, and can be added 0.3% or less. However, 0.001% or less is preferable in the case of ingot in a shaft furnace.

Cr, Co, Ag, In, Be, Al, Ti, V, Zr, Mo, Hf, Ta, B and the like have a function of preventing coarsening of crystal grains, and can be added in an amount of 0.1% or less.

Pb is an impurity and preferably limited to 0.001% or less.

Next, the structure of the copper alloy plate which concerns on this invention is demonstrated.

The copper alloy plate which concerns on this invention has the structure which the precipitate of the Ni-P intermetallic compound disperse | distributed in the copper alloy mother phase. Particles having a diameter exceeding 60 nm in the precipitates cause cracking in bending processing with a small R / t (R: bending radius, t: sheet thickness), and when present, bending workability decreases. On the other hand, when the precipitate particles deviate from the spherical shape, the circumscribed circle diameter (long diameter) of the precipitate particles is taken as the diameter of the precipitate in the present invention.

On the other hand, the precipitate becomes a starting point of cracks during shear punching, and the one where it is distributed at a higher density has better shear punching property. Fine precipitates, such as less than 5 nm in diameter, cause local work hardening characteristics at the shear stress field, and contribute to propagation and propagation of shear punching. However, when precipitates of 5 nm or more in diameter are finely dispersed, they exist. Since the wavefront of the shear punching advances by moving from place to place, the punching characteristics are further improved and it is helpful for reducing burrs. Therefore, for particles having a diameter of 60 nm or less that does not lower the bendability, it is preferable that 20 or more are present in the visual field of 500 nm x 500 nm in average of 20 or more, more preferably 30 or more.

Next, the manufacturing method of the copper alloy plate which concerns on this invention is demonstrated.

The copper alloy sheet according to the present invention is subjected to hot rolling and cold rough rolling after homogenizing the copper alloy ingot, followed by continuous continuous annealing to the copper alloy sheet after cold rough rolling, and by adding cold rolling and stabilizing annealing. It can manufacture.

Since the copper alloy of the present invention is not a precipitated copper alloy, in the homogenization treatment, hot rolling and cold rough rolling, no particular rigorous management is necessary in terms of conditions. For example, the homogenization treatment is performed at 800 to 1000 ° C. × 0.5 to 4 hours, hot rolling at 800 to 950 ° C., and after the hot rolling, water cooling or cooling is performed. Cold rough rolling selects the processing rate so that a processing rate of about 30 to 80% is obtained in the final finish rolling. Intermediate recrystallization can be appropriately sandwiched during cold rough rolling.

On the other hand, with respect to the continuous continuous annealing of the copper alloy plate after the rough cold rolling, it is necessary to strictly control and set the appropriate holding temperature and the holding time.

One of the great features of the alloy system defined in the present invention is that the precipitated phase transitions at annealing exceeding 650 ° C. for several tens of seconds of holding time. As described above, a relatively large number of coarse precipitates are observed when the holding temperature is low. In thermodynamics, when the holding temperature is higher, the precipitates are usually coagulated and coarsened. However, in the present alloy system, the precipitated phase transitions at the boundary of 600 to 650 ° C. That is, the coarse precipitate which generate | occur | produced in the low temperature area | region decomposes and re-disposes at the temperature of 600-650 degreeC vicinity, and the new phase which precipitates a fine Ni-P compound is expressed. This precipitate contributes to improvement of bending workability and reduction of punching burr.

When the holding temperature is low, precipitate particles larger than 60 nm are easily observed, and particles having a diameter of 60 nm or less are insufficient in a composition region in which the content of Ni and P is extremely small. On the other hand, even at an annealing temperature exceeding 650 ° C, if the holding time is short, decomposition and re-use of the coarse precipitates are insufficient, and fine precipitates are less likely to be expressed, and precipitates exceeding 60 nm in diameter remain. On the contrary, if it is too long, there exists a possibility that recrystallized particle may coarsen and it may cause the fall of bending workability.

In the case of the copper alloy composition of the present invention, the precipitate of the Ni-P intermetallic compound in the copper alloy matrix is maintained by maintaining the temperature at a temperature exceeding 650 ° C. and maintaining the holding time for 15 to 30 seconds. A properly distributed organization can be obtained. It is preferable to quench at a cooling rate of 10 degrees C / sec or more after annealing.

On the other hand, by performing finishing annealing temperature on the conditions of a high temperature short time as mentioned above, there exists also an advantage that the precipitate of the Ni-P intermetallic compound precipitated in the temperature rising process is reusable, and the solid solution Ni required for the improvement of stress relaxation resistance is fully obtained.

It is preferable to make the stabilized annealing after final finishing rolling into 250-450 degreeCx20 to 40 second. This is because the deformation introduced in the final finish rolling is eliminated, and there is no softening of the material, so that the decrease in strength is small.

Example 1

An embodiment of the present invention will be described below. Various copper alloy plates of Cu-Ni-Sn-P alloys having different states of Ni compounds in the structure were produced, and properties such as strength, electrical conductivity, and stress relaxation resistance were evaluated.

Specifically, the copper alloys of the respective chemical composition shown in Table 1 were each dissolved in a coreless furnace, and then annealed by a semi-continuous casting method to obtain an ingot having a thickness of 70 mm × width 200 mm × length 500 mm. Each of these ingots was rolled on the following common conditions, and the copper alloy thin plate was produced. After the surface of each ingot was faced and heated, it was hot rolled to a plate having a thickness of 16 mm, and rapidly cooled in water from a temperature of 650 ° C or higher.

After removing the oxidation scale, this plate was subjected to cold rolling → continuous annealing → cold rolling → strain removal annealing to prepare a copper alloy thin plate. In other words, the plate after primary cold rolling (crude cold rolling, medium-tension cold rolling) is faced, and the finish annealing is carried out by continuous annealing which is maintained for 20 seconds at an actual temperature of 660 ° C., followed by a cold rolling finish of 50%. Was done. However, inventive example 16 and comparative example 19 of Table 2 have a Sn content of less than 0.1%, so that softening (recrystallization during annealing) due to annealing cannot be suppressed and the strength is lowered. It was relatively high at 80% to improve the strength. Then, low temperature strain removal annealing at an actual temperature of 400 ° C. × 20 seconds was performed to obtain a copper alloy thin plate having a thickness of 0.25 mm.

At this time, as shown in Table 2, the time required from the completion of the alloy element addition in the melting furnace to the start of casting (in Table 2, the time required until the start of casting), the cooling solidification rate at the time of casting, the furnace extraction temperature, hot rolling The time required from the end temperature and the heating furnace extraction to the end of the hot rolling (described in Table 2 as the time required for the end of the hot rolling) was changed in various ways to control the state of the Ni compound in the copper alloy sheet structure.

From each of the copper alloy thin plates thus obtained, 10 g of the extraction residue measurement specimen was taken, and the amount of Ni contained in the extraction residue extracted and separated by a 0.1 μm mesh of pores by the above-described method was subjected to ICP emission spectrometry. Obtained by And the ratio (%) with respect to Ni content of the said copper alloy was calculated | required. These results are shown in Table 2.

In addition, the sample was cut out from each obtained copper alloy plate with each example, and the tensile strength, the electrical conductivity measurement, the stress relaxation rate measurement, and the bending test were done. These results are also shown in Table 2.

(Tension test)

The test piece was extract | collected from the said copper alloy thin plate, and the JIS No. 5 tensile test piece was produced by machining so that a test piece longitudinal direction might become a right angle direction with respect to the rolling direction of a board. And mechanical characteristics were measured on the conditions of room temperature, the test speed of 10.0 mm / min, and GL = 50 mm with the 5882 type Instron universal testing machine. On the other hand, the yield strength is tensile strength corresponding to 0.2% of permanent elongation.

(Measurement of conductivity)

A sample was taken from the copper alloy thin plate and the electrical conductivity was measured. The electrical conductivity of the copper alloy plate sample was processed by milling a 10 mm wide x 300 mm thin paper-like test piece by milling, and the electrical resistance was measured by a double bridge type resistance measuring device in accordance with the non-ferrous metal material conductivity measurement method specified in JIS-H0505. Was measured and the electrical conductivity was computed by the average cross-sectional method.

(Stress Relief Characteristics)

The stress relaxation ratio in the direction perpendicular to the rolling direction of the copper alloy thin plate was measured, and the stress relaxation resistance in this direction was evaluated. Specifically, the test piece was extract | collected from the said copper alloy thin plate, and it measured using the cantilever system shown in FIG. 10 mm wide thin paper-like test piece 1 (the length direction becomes the direction perpendicular to the rolling direction of the plank) is cut out, and its one end is fixed to the rigid test bench 2, and the span length of the test piece 1 The amount of warpage of the size d (= 10 mm) is given to the part of (L). At this time, L is determined so that the surface stress corresponding to 80% of the material strength is loaded on the material. This was obtained after holding for 30 hours in an oven at 180 ° C, the permanent strain (δ) when the warpage amount (d) was removed was measured, and the stress relaxation ratio (RS) was calculated at RS = (δ / d) x 100. do. On the other hand, holding | maintenance of 180 degreeC * 30 hours is corresponded to holding | maintenance of nearly 150 degreeC * 1000 hours, when it calculates by a Rason mirror parameter.

(Evaluation test of bending workability)

The bending test of the copper alloy plate sample was performed according to the Nippon Shindo Association technical standard. The board was cut into a width of 10 mm and a length of 30 mm, and GoodWay (bending axis perpendicular to the rolling direction) was bent at a bending radius of 0.5 mm, and the presence or absence of cracking at the bent portion was visually observed with a 50 times optical microscope. (Circle) and the thing which a crack generate | occur | produced the thing without a crack.

As apparent from Table 2, inventive examples 101 to 116, which are copper alloys (alloys Nos. 1 to 13) in the present invention composition of Table 1, have a casting time from completion of alloy element addition in the melting furnace to casting start within 1200 seconds. The cooling solidification rate at the time of 0.5 degreeC / sec or more and the time required from the heating furnace extraction to the hot-rolling start are manufactured in the preferable conditions within 1200 second. In addition, the furnace extraction temperature and the hot rolling end temperature are also appropriate.

For this reason, Inventive Examples 101-116 of Table 2 have coarse Ni oxide exceeding 0.1 micrometer so that the ratio with respect to the alloy Ni content of Ni amount in the extraction residue extracted and isolate | separated by the above-mentioned extraction residue method may be 80% or less. Ni compounds, such as a crystallized substance and a precipitate, are suppressed. Therefore, it is estimated that the quantity of the fine Ni compound (including fine Ni clusters of nano level or less) and 0.1 micrometer or less and high capacity of Ni can be ensured.

As a result, Inventive Examples 101 to 116 can achieve high stress relaxation resistance of 15% or less in stress relaxation rate in a direction perpendicular to the rolling direction. Moreover, it has the outstanding characteristics for terminal connectors, such as the outstanding bending characteristic and the outstanding strength.

However, in the comparison in Inventive Examples 101 to 106 shown in Table 2, Inventive Examples 102 and 106, which require a relatively long time from completion of the alloy element addition in the melting furnace to the start of casting, have a long time from extraction of the furnace to start of hot rolling. Relatively long invention examples 103 and 104 have relatively low stress relaxation resistance compared with these comparatively short invention examples 101 and 105.

Further, among Inventive Examples 101 to 116 of Table 2, Inventive Examples 109 to 115 (alloy Nos. 6 to 12 of Table 1) in which the amount of other elements exceed the above-mentioned preferred upper limit, the electrical conductivity is higher than that of Inventive Examples 101 to 108. It is supposed to be low.

Inventive Examples 109-113 have Fe, Zn, Mn, Si, and Mg exceeding the above-mentioned preferable upper limits like Alloy No. 6-10 of Table 1, respectively.

Inventive Example 114, the sum of the elements of Ca, Zr, Ag, Cr, Cd, Be, Ti, Co, Au, Pt is higher than the above-mentioned preferred upper limit of 1.0 mass% as shown in Alloy No. 11 in Table 1.

Inventive Example 115 is Hf, Th, Li, Na, K, Sr, Pd, W, S, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, Bi, Te The total of B, and misch metal is high, exceeding the above-mentioned preferred upper limit of 0.1% by mass as in Alloy No. 12 in Table 1.

On the other hand, inventive example 116, like the alloy 13 of Table 1, had a low Sn content of less than 0.1% and improved the strength by relatively high the reduction ratio of the finish cold rolling as described above, but it was different by softening by annealing. Compared with the invention, the strength is relatively low.

On the other hand, although the comparative examples 123-126 of Table 2 are copper alloys (alloy number 1) in the composition of this invention of Table 1, manufacturing conditions deviate from a preferable range, respectively.

In Comparative Examples 123 and 124, the time required from the completion of the alloy element addition in the melting furnace to the start of casting is too long, exceeding 1200 seconds. In Comparative Examples 125 and 126, the time required from the heating furnace extraction to the start of hot rolling is too long, exceeding 1200 seconds.

For this reason, the comparative examples 123-126 of Table 2 have the coarse Ni which the ratio with respect to the alloy Ni content of the amount of Ni in the extraction residue extracted and isolate | separated by said extraction residue method exceeding 40%, and exceeding 0.1 micrometer. Too many Ni compounds such as oxides, crystals, and precipitates are not suppressed. Therefore, it is estimated that the quantity of the fine Ni compound etc. which are 0.1 micrometer or less, and the solid solution amount of Ni are not ensured.

As a result, the stress relaxation resistance in the direction perpendicular to the rolling direction of Comparative Examples 123 to 126 is significantly lower than that of the invention example.

In Comparative Examples 117 to 122 of Table 2, copper alloys other than the inventive composition of Alloy Nos. 14 to 19 in Table 1 were used. For this reason, although the manufacturing conditions are in the preferable range, the ratio of the amount of Ni in the extraction residue to the alloy Ni content, the stress relaxation resistance, the bending characteristics, the electrical conductivity, and the strength are all inferior to the invention examples.

In the copper alloy of Comparative Example 117, the Ni content was lower than the lower limit (alloy number 14 in Table 1). For this reason, strength and stress relaxation resistance are low.

In the copper alloy of Comparative Example 118, the Ni content is higher than the upper limit (alloy number 15 in Table 1). For this reason, strength, stress relaxation resistance, and bending workability are low.

In the copper alloy of Comparative Example 119, the content of Sn is lower than the lower limit (alloy number 16 in Table 1). For this reason, in Comparative Example 119, although the reduction ratio of the finish cold rolling was relatively high as described above, the strength was improved, but the strength was too low due to softening by annealing.

In the copper alloy of Comparative Example 120, the content of Sn is out of the upper limit (alloy number 17 in Table 1). For this reason, electrical conductivity is low.

In the copper alloy of Comparative Example 121, the content of P is lower than the lower limit (alloy number 18 in Table 1). For this reason, the strength and stress relaxation resistance are low.

In the copper alloy of Comparative Example 122, the content of P is out of the upper limit (alloy number 19 in Table 1). For this reason, strength, stress relaxation resistance, and bending workability are low.

From the above results, it is preferable to obtain a component composition, structure, and structure of the copper alloy sheet of the present invention for improving the stress relaxation resistance and bending workability in a direction perpendicular to the rolling direction after increasing the high strength and high electrical conductivity. The significance of the condition is supported.

Example 2

Next, the Example of the copper alloy plate which concerns on Embodiment 2 of this invention is demonstrated.

The copper alloy was dissolved under a charcoal coating in air at Cryptolo to obtain 45 mm thick ingots (Nos. 201 to 209) having the compositions shown in Table 3. Subsequently, after cracking treatment at 965 ° C. for 3 hours or at 850 ° C. for 30 minutes, hot rolling was carried out to a thickness of 15 mm. Rough rolling was carried out to the thickness shown in Table 3.

Then, No. For 201 to 208, finish continuous annealing is performed, and No. About 209, batch type intermediate | middle and finishing annealing were performed through cold rolling, and also cold finishing (stabilization annealing) was performed after finishing cold rolling. The conditions of each process are shown in Table 3. On the other hand, the final product plate thickness is 0.25mm.

For each specimen in the final product state obtained, electrical conductivity, hardness, mechanical properties (tensile strength, strength, elongation), elastic limit value, stress relaxation resistance, bending workability and shear punching resistance were measured by the following methods. The distribution state of the precipitate was observed with a transmission electron microscope (TEM). The results are shown in Table 4.

Conductivity; Conductivity measurement was performed by the 4-terminal method using a double bridge based on the nonferrous metal material conductivity measurement method prescribed | regulated to JIS-H0505.

Hardness; The hardness was measured based on the microhardness test method specified in JIS-Z2251, and the beaker hardness was measured at a test weight of 100 g (0.9807N).

Mechanical properties; The JIS5 tensile test piece was produced by machining so that a longitudinal direction might become parallel direction (LD) and a vertical direction (TD) with respect to the rolling direction of a board | plate, and it measured by carrying out a tension test based on JIS-Z2241. The yield strength is tensile strength corresponding to 0.2% of permanent elongation.

Elastic limit value; It was calculated | required by the moment type test using the Akashi elastic limit value tester (MODEL: APT). The test direction of the material was made into the parallel direction (LD) and the vertical direction (TD) with respect to the rolling direction of the plank.

Stress relaxation resistance; The stress relaxation rate was measured using the cantilever system shown in FIG. The 10-mm-thick thin paper-like test piece 1 is cut out so that the longitudinal direction is parallel to the rolling direction of the board and the perpendicular direction (TD), and one end thereof is fixed to the rigid test bench 2 to test the test piece. The amount of warpage of d (= 10 mm) is given to the part of span length L of (1). At this time, L is determined so that the surface stress corresponding to 80% of the material strength is loaded on the material. After holding this in oven at 180 degreeC for 30 hours, it is taken out, the permanent deformation (delta) at the time of the curvature removal is measured, and stress relaxation rate (RS) is calculated by RS = ((delta / d) x100). On the other hand, holding | maintenance of 180 degreeC * 30 hours is corresponded to holding | maintenance of nearly 150 degreeC * 1000 hours, when it calculates by a Rason mirror parameter.

Bending workability; Specimens of width 10 mm and length 35 mm are cut out so that the longitudinal direction is parallel to the rolling direction of the plank and the perpendicular direction, so that the bend line is perpendicular to the longitudinal direction, as specified in the CESM0002 metal material W bending test. After cutting using a type B bending jig, 90 ° W bending at R / t = 2 (R: bending radius, t: sheet thickness) using a Shimanzu universal testing machine RH-30 with a load of 1t, The presence or absence of a crack was evaluated and the thing which a crack generate | occur | produced was made into x.

Shear punching property; The shear burr height was measured in accordance with the Nippon Shinsai Association standard JCBAT310 (shear test method for thin copper and copper alloy sheet). Specifically, the test material to which Mitsubishi Unipress PA-5 lubricating oil was previously apply | coated with the brush is penetrated circularly by the punching press of a punch diameter of 10.000 mm, and a die diameter of 10.040 mm. The clearance of this punching press is (one space | interval (gap of die cutting degree and periphery of punch) / plate | board thickness of test material) x 100 (%)) = 8%, and a shear rate is 50 mm / min. Burrs generated around the punched circular hole were measured at four locations every 90 degrees of the circumference, and the average value was taken to set the burr height.

Observation of the distribution of precipitates; A test material is prepared in the thin film for TEM observation by the electrolytic thin film method (twinjet method). This was imaged at a shooting magnification of 40000 times and 100000 times using a TEMH-800 (acceleration voltage 200kV) manufactured by Hitachi, and enlarged by 1.5 times to print on photo paper. The number of precipitates exceeding 60 nm in diameter in a square field of 1000 nm x 1000 nm on this 60000-times photographic paper, and the number of precipitates of 5 nm to 60 nm in diameter in a square field of 500 nm x 500 nm on a 150000-fold photographic paper are counted. This is observed by plural visual fields to calculate an average value. In addition, all the said precipitate particle observed in the visual field was spherical.

As shown in Table 4, No. 2, which had no precipitates larger than 60 nm in diameter, was observed. 201 to 207 are excellent in bending workability in both LD and TD directions. Furthermore, No. 20 in which more than 20 precipitates with a diameter of 5 nm or more and 60 nm or less were observed within a 500 nm × 500 nm visual field. 201 to 204 and no. 208 has a small average burr height, in particular No. The burr height of 201 to 204 is small. In addition, No. The stress relaxation ratios of 201 to 204 were 15% or less in both the LD and TD directions.

In comparison, No. In 205 to 207, coarse precipitates exceeding 60 nm are less likely to occur due to a small amount of Ni added, but because of the low finishing annealing temperature, the number of precipitates of fine Ni-P compounds is also increased without transferring to the fine precipitated phenomena occurring around 650 ° C. Do not reach the regulations. Since 60 micrometers or less of fine precipitates which improve shear property are lacking, burr height exceeds 10 micrometers and it is inferior to shear punching property. Since the amount of added Ni is small and the solid solution Ni in the matrix disappears from the precipitate, the Ni solid solution does not reach an amount capable of maintaining the stress relaxation characteristics, and the stress relaxation ratio is high (particularly in the TD direction).

No. Since 208 does not reach 600 degreeC and 650 degreeC in finishing annealing temperature, the coarse precipitate exceeding 60 nm does not fully decompose | disassemble and re-use, and it remains in part, and bending workability is inferior. Although it does not completely transition to the fine precipitated image which occurs around 650 ° C, since the amount of Ni is large, some fine precipitates are generated and the burr height is kept low. In addition, since the total amount of Ni-P precipitates is large and the Ni stock capacity is insufficient, the solid solution Ni necessary for improving the stress relaxation resistance is not sufficiently obtained, and the stress relaxation ratio in the TD direction is high.

No. 209 is a state in which the precipitate aggregated to 60 nm or more by batch annealing below 650 degreeC. Although the recrystallization is completed by performing two batch annealing, since the temperature which decompose | disassembles agglomerated precipitate and expresses a fine precipitate is not reached, bending workability falls and burr height also increases.

As described above, according to the present invention, a Cu-Ni-Sn-P-based alloy having high stress relaxation resistance in a direction perpendicular to the rolling direction and having high strength, high electrical conductivity, and excellent bending workability can be provided. As a result, it is especially applicable to the connection parts, such as an automotive terminal and connector, to the use which requires the stress relaxation resistance of a direction perpendicular | vertical to a rolling direction.

Claims (9)

It is a copper alloy which contains Ni: 0.1-3.0% (mass%, same or less), Sn: 0.01-3.0%, P: 0.01-0.3%, respectively, and consists of remainder copper and an unavoidable impurity, and it makes a hole by an extraction residue method. As a copper alloy excellent in the stress relaxation resistance, Ni amount in the extraction residue extracted and separated on the filter of 0.1 micrometer of size is 40% or less by the ratio with respect to Ni content in the said copper alloy, In the extraction residue method, 10 g of the copper alloy is immersed in 300 ml of a 10% by mass ammonium acetate methanol solution, and the copper alloy is used as an anode, while platinum is used as a cathode, at a current density of 10 mA / cm ² . Constant current electrolysis is carried out, and the solution in which the copper alloy is dissolved is suction filtered through a polycarbonate membrane filter having a pore size of 0.1 µm, and the undissolved residues are separated and extracted on the filter. The amount of Ni in the extraction residue is obtained by dissolving the undissolved residue on the filter by a solution in which aqua regia and water are mixed in a ratio of 1 to 1, and then analyzing the copper residue by ICP emission spectroscopy. The method of claim 1, The copper alloy further said Fe: 0.5% or less, Zn: 1% or less, Mn: 0.1% or less, Si: 0.1% or less, Mg: 0.3% or less. The method according to claim 1 or 2, The copper alloy in which the said copper alloy further made content of Ca, Zr, Ag, Cr, Cd, Be, Ti, Co, Au, Pt to 1.0% or less in total of these elements. The method according to any one of claims 1 to 3, The copper alloy is Hf, Th, Li, Na, K, Sr, Pd, W, S, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, Bi, Te , B, copper alloy which made content of misch metal into 0.1% or less in total of these elements. Ni: 0.4-1.6%, Sn: 0.4-1.6%, P: 0.027-0.15%, Fe: 0.0005-0.15%, Ni / P which is ratio of Ni content and P content is less than 15, and remainder is substantially It has a composition consisting of Cu and impurities, and has a structure in which precipitates are dispersed in a copper alloy matrix, and the precipitates are 60 nm or less in diameter, and 20 or more of 5 nm or more and 60 nm or less are observed within a 500 nm x 500 nm field of view. Copper alloy. The method of claim 5, The copper alloy further contains any one or more of Zn: 1% or less, Mn: 0.1% or less, Si: 0.1% or less, and Mg: 0.3% or less. The method according to claim 5 or 6, The copper alloy is a copper alloy containing 0.1% or less of Cr, Co, Ag, In, Be, Al, Ti, V, Zr, Mo, Hf, Ta, B in total. The copper alloy plate for electrical connection parts using the copper alloy in any one of Claims 1-7. A method for producing a copper alloy plate using the copper alloy according to any one of claims 1 to 4, wherein the copper alloy sheet is obtained when the copper alloy sheet is obtained by casting, hot rolling, cold rolling, or annealing the copper alloy. Stress relaxation resistance of the time required from completion of addition of alloying elements in the melting furnace to the start of casting is within 1200 seconds, and the time required from extraction of the ingot from the heating furnace of the ingot to the end of hot rolling is 1200 seconds or less. Excellent method for producing a copper alloy plate.

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