JP7432315B2 - Method for manufacturing copper alloy seamless pipe and method for manufacturing heat exchanger - Google Patents

Description

The present invention relates to a copper alloy material that has low manufacturing cost, high strength, and excellent workability.

Conventionally, copper alloys to which trace amounts of elements are added have been proposed for the purpose of increasing the strength of copper materials. One of them is a Cu--Ni--P based copper alloy (for example, Patent Document 1: Japanese Unexamined Patent Publication No. 4-218631).

This Cu-Ni-P-based copper alloy is a copper alloy that is precipitation-strengthened by Ni-P-based precipitates, and can be strengthened by heat treatment (aging treatment) at an appropriate temperature after solution treatment. be converted into

Various forms of the same material, such as plates and pipes, are manufactured using Cu-Ni-P copper alloys, but depending on the application and conditions of use, they may be processed to increase their strength. Cu-Ni-P-based copper alloy materials must not only have high strength but also good workability, and copper materials with good elongation are required.

In the case of pipe materials, for example, copper pipes used for heat exchangers for air conditioners such as room air conditioners and package air conditioners, heat transfer tubes for refrigerators, and refrigerant piping, due to the recent demand for thinner walls, the materials are becoming more expensive. Strengthening is required. For this purpose, it is important not only to use appropriate alloy components but also to specify manufacturing conditions such as appropriate heat treatment conditions according to the alloy components.

However, the Cu-Ni-P-based copper alloy material described in Patent Document 1 has a strength (tensile strength) of over 300 MPa, and although it has high strength, it has low elongation and is difficult to perform heavy processing. is not suitable.

Therefore, as a Cu-Ni-P based copper alloy material that has high strength and excellent workability, for example, Patent Document 2 describes 0.40 to 1.50% by mass of Ni and 0.10 to 0.0% by mass of Ni. After solution treatment of a copper alloy containing 50% by mass of P and the remainder Cu and unavoidable impurities, cold working and intermediate annealing are performed, and the copper alloy is heated at 650°C ± 100°C. It is disclosed that a copper alloy material with high strength and elongation can be obtained by performing heat treatment and then a second heat treatment of heating at 850° C.±100° C.

Japanese Patent Application Publication No. 4-218631 International Publication No. 2015/122423

Copper alloy materials are highly versatile and are used for a variety of purposes, so they are required not only to have high performance but also to be low cost.

Here, one possible measure for reducing costs in the production of copper alloy materials is to lower the processing temperature of heat treatment.

In the method of Patent Document 2, a copper alloy material having excellent performance of high strength and high elongation can be obtained, but the first heat treatment of heating at 650°C ± 100°C and the heating at 850°C ± 100°C A second heat treatment is essential.

In Patent Document 2, the second heat treatment heated at 850 ° C ± 100 ° C corresponds to brazing heating, so when the copper alloy material is applied to a product by brazing, it is an unavoidable heat treatment, It is difficult to lower this heat treatment temperature. On the other hand, in Cited Document 2, the first heat treatment of heating at 650° C.±100° C. is a heat treatment before brazing heating, so there is room for improvement.

However, in Cited Document 2, the temperature range of the first heat treatment is specified as 550 to 750°C, which is why the effect of Cited Document 2, that is, high strength, can only be achieved when heat treatment is performed in this temperature range. This is because a copper alloy material with high elongation can be obtained.

Therefore, it is easily inferred from common technical knowledge that a copper alloy material with high strength and elongation cannot be obtained simply by lowering the processing temperature of the first heat treatment to reduce manufacturing costs.

Therefore, an object of the present invention is to provide a Cu--Ni--P based copper alloy material that is low in cost, has high strength, and has excellent workability.

Based on the above technical background, as a result of extensive studies, the present inventors set the content of Ni and P in the copper alloy within a specific range, and then aged the copper alloy at a low temperature. _It was discovered that by heat treatment at 225 ± 100 ° C., Ni ₁₂ P ₅ , which is a precipitate different from that precipitated by aging treatment at 500 to 750 ° C., _precipitates . It was discovered that this contributes to making a copper alloy high in strength and elongation, and the present invention was completed.

That is, the present invention (1) is a casting of a copper alloy containing 0.40 to 1.50% by mass of Ni and 0.10 to 0.50% by mass of P, with the remainder being Cu and unavoidable impurities. A casting process is performed to obtain an ingot, then the ingot of the copper alloy is heated and homogenized, the homogenized copper alloy is hot worked, and then the hot worked copper alloy is produced. This is a method for manufacturing copper alloy seamless pipes by cold working.
During the period from the hot working to the cold working or after the cold working, a solution treatment is performed, and after the solution treatment, a heat treatment (A1) of heating at 225 ° C ± 100 ° C is performed,
In the heat treatment (A1), the difference (σ2-σ1) between the tensile strength (σ2) after the heat treatment (A1) and the tensile strength (σ1) before the heat treatment (A1) is 20 MPa or more, and the heat treatment (A1) The difference (δ1-δ2) between the elongation before (δ1) and the elongation (δ2) after the heat treatment (A1) is 0 to 10% ;
The present invention provides a method for manufacturing a copper alloy seamless pipe characterized by the following.

In addition, the present invention (2) is a casting of a copper alloy containing 0.40 to 1.50% by mass of Ni and 0.10 to 0.50% by mass of P, with the balance being Cu and unavoidable impurities. A casting process is performed to obtain an ingot, then the ingot of the copper alloy is heated and homogenized, the homogenized copper alloy is hot worked, and then the hot worked copper alloy is produced. This is a method for manufacturing copper alloy seamless pipes by cold working.
Solution treatment is performed during or after the cold working from the hot working to the cold working, and after the solution treatment, heating at 850 ± 100°C, and then heating at 50°C from the heating temperature to 300°C. A process (B) of cooling at an average cooling rate of /second or less is performed, and after the process (B), a heat treatment (A2) of heating at 225 ° C ± 100 ° C is performed,
In the treatment (B) and the heat treatment (A2), the difference (σ2-σ1) between the tensile strength (σ2) after the heat treatment (A2) and the tensile strength (σ1) before the treatment (B) is 30 MPa or more. and the difference (δ1-δ2) between the elongation (δ1) before the treatment (B) and the elongation (δ2) after the heat treatment (A2) is 0 to 10% ;
The present invention provides a method for manufacturing a copper alloy seamless pipe characterized by the following.

In addition, the present invention (3) provides the copper alloy joint of (1) or (2), wherein the copper alloy contains precipitates, and all or part of the precipitates are Ni ₁₂ P ₅ . The present invention provides a method for manufacturing a tubeless product .

In addition, the present invention ( 4 ) provides a heat exchanger characterized in that a heat exchanger is obtained using a copper alloy seamless pipe obtained by carrying out the method for producing a copper alloy seamless pipe according to any one of ( 1 ) to (3). A method for manufacturing an exchanger is provided.

According to the present invention, it is possible to provide a Cu--Ni--P based copper alloy material that is low in cost, has high strength, and has excellent workability.

The copper alloy material of the first embodiment of the present invention contains 0.40 to 1.50% by mass of Ni and 0.10 to 0.50% by mass of P, with the balance consisting of Cu and inevitable impurities. Made of copper alloy,
The copper alloy is a copper alloy that has been subjected to a solution treatment to make the copper alloy a solution, and a heat treatment (A1) in which the copper alloy is heated at 225 ° C ± 100 ° C after the solution treatment,
The difference (σ2-σ1) between the tensile strength (σ2) after the heat treatment (A1) and the tensile strength (σ1) before the heat treatment (A1) is 20 MPa or more, and the elongation before the heat treatment (A1) is (δ1) and the elongation (δ2) after the heat treatment (A1) (δ1-δ2) is 0 to 10%;
It is a copper alloy material characterized by:

Copper alloy materials are manufactured by first casting a copper alloy ingot with a predetermined chemical composition and then subjecting it to various processing and treatments. During the treatment, a copper alloy of a specific chemical composition is used, namely 0.40-1.50% by weight of Ni, preferably 0.70-1.20% by weight of Ni and 0.10-0.50% by weight of Ni. Solution treatment of a copper alloy containing mass% of P, preferably 0.20 to 0.40 mass% of P, followed by heat treatment at 225°C ± 100°C (A1) It has been found that by carrying out this process, precipitates having a composition of Ni ₁₂ P ₅ can be precipitated in the copper alloy, and the strength of the copper alloy material can be improved by precipitation strengthening.

The copper alloy material of the first embodiment of the present invention contains 0.40 to 1.50% by mass of Ni and 0.10 to 0.50% by mass of P, with the balance consisting of Cu and inevitable impurities. It is made of copper alloy. In addition, in the present invention, the content of Ni and P refers to the content of Ni and P in the copper alloy material after heat treatment (A1).

The Ni content of the copper alloy material of the first embodiment of the present invention is 0.40 to 1.50% by mass. Ni is a component that forms a precipitate with a composition of Ni ₁₂ P ₅ due to a compound with P in the copper alloy when the copper alloy is heated at 225 ° C ± 100 ° C, improving the tensile strength. . When the Ni content is within the above range, the tensile strength of the copper alloy material becomes high. On the other hand, if the Ni content exceeds the above range, the elongation will be low, and the workability, for example, the strength of bending in the case of plate materials, the hairpin bending work and expandability in the case of pipe materials, will be reduced. If the Ni content is less than the above range, the strength of the copper alloy material will be low. In particular, when the copper alloy material of the first form of the present invention is a pipe material, the Ni content of the copper alloy material of the first form of the present invention is 0, since the pipe material has high strength and excellent workability. It is preferably .70 to 1.20% by mass.

The P content of the copper alloy material of the first embodiment of the present invention is 0.10 to 0.50% by mass. P is a component that forms a precipitate with a composition of Ni ₁₂ P ₅ by a compound with Ni in the copper alloy when the copper alloy is heated at 225 ° C ± 100 ° C, improving the tensile strength. . When the P content is within the above range, the tensile strength of the copper alloy material becomes high. On the other hand, if the P content exceeds the above range, workability may decrease and cracks may occur during hot working or cold working, and if the P content is below the above range, the amount of precipitates As a result, the strength of the copper alloy material decreases. In particular, when the copper alloy material of the first form of the present invention is a pipe material, the P content of the copper alloy material of the first form of the present invention is 0, since the pipe material has high strength and excellent workability. It is preferably .20 to 0.40% by mass.

The copper alloy material of the first embodiment of the present invention contains 0.40 to 1.50 mass% Ni, preferably 0.70 to 1.20 mass% Ni, and 0.10 to 0.50 mass% Ni. A copper alloy containing P, preferably 0.20 to 0.40% by mass of P, and the remainder consisting of Cu and unavoidable impurities, is solution treated, and after the solution treatment, heated at 225 ° C ± 100 ° C. It is made of a copper alloy obtained by heat treatment (A1). That is, the copper alloy material of the first embodiment of the present invention contains 0.40 to 1.50 mass% of Ni, preferably 0.70 to 1.20 mass% of Ni, and 0.10 to 0.50 mass% of Ni. % of P, preferably 0.20 to 0.40 mass % of P, and the remainder is Cu and unavoidable impurities. In the process of obtaining a copper alloy material by performing hot working such as cold working, cold working such as cold rolling, cold drawing, etc., and various heat treatments, the copper alloy is heated at 700 to 900°C, preferably 800 to 900°C. It is obtained by performing a solution treatment of heating and quenching, followed by a heat treatment (A1) of heating at 225° C.±100° C. By setting the heat treatment temperature in the heat treatment (A1) within the above range, Cu-Ni-P-based precipitates containing at least a portion of precipitates having a composition of Ni ₁₂ P ₅ are precipitated. On the other hand, if the heat treatment temperature in heat treatment (A1) is lower than the above range, precipitates having a composition of Ni ₁₂ P ₅ are difficult to precipitate, and even if the temperature exceeds the above range, precipitates having a composition of Ni ₁₂ P ₅ are difficult to precipitate. Precipitates are difficult to separate.

The heat treatment time in heat treatment (A1) is preferably 10 to 1000 minutes, particularly preferably 30 to 600 minutes. When the heat treatment time in heat treatment (A1) is within the above range, a precipitate having a composition of Ni ₁₂ P ₅ in a sufficient amount to be able to obtain the effect of improving the strength of the first copper alloy material of the present invention. can be precipitated. On the other hand, if the heat treatment time in heat treatment (A1) is less than the above range, the amount of precipitates having a composition of Ni ₁₂ P ₅ tends to decrease, making it difficult to obtain the effect of improving the strength of the copper alloy material, and If the content exceeds the above range, the precipitates will become large and the strength of the copper alloy material will tend to decrease.

In the present invention, "the solution treatment and the heat treatment (A1) were performed after the solution treatment" means that the copper alloy is subjected to the heat treatment (A1) immediately after the solution treatment. It does not only mean that the treatment or process is carried out between the solution treatment and the heat treatment (A1), but also that a "treatment or process that does not involve heating" and/or "a treatment or process that involves heating at a temperature exceeding 325°C" is performed. may be done. That is, the copper alloy may be subjected to heat treatment (A1) immediately after being subjected to solution treatment, or after being subjected to solution treatment, a "treatment or process that does not involve heating" and/or Alternatively, the heat treatment (A1) may be performed after a "treatment or step of heating at a temperature exceeding 325°C" is performed. In addition, after the solution treatment is performed and before the heat treatment (A1) is performed, the copper alloy may be heated to a temperature in the range of 125 to 325°C for a short period of time that does not affect the effects of the present invention. may be exposed. For example, if a treatment or process that involves heating at a temperature exceeding 325°C is performed after solution treatment and before heat treatment (A1) is performed, the temperature must be raised to a predetermined temperature. Therefore, it passes through a temperature range of 125 to 325°C, but it is acceptable as long as the time for passing through the temperature range of 125 to 325°C is short enough not to affect the effects of the present invention. Moreover, treatment or processing at a temperature of less than 125° C. may be performed between the solution treatment and the heat treatment (A1).

The copper alloy material of the first embodiment of the present invention has a difference (σ2-σ1) between the tensile strength (σ2) after heat treatment (A1) and the tensile strength (σ1) before heat treatment (A1) of 20 MPa or more, It is preferably made of a copper alloy having a pressure of 30 MPa or more, particularly preferably 40 MPa or more.

The tensile strength (σ) of the copper alloy material of the first embodiment of the present invention is preferably 200 to 280 MPa, particularly preferably 240 to 280 MPa. Note that the tensile strength (σ) of the copper alloy material of the first embodiment of the present invention refers to the tensile strength of the copper alloy material after heat treatment (A1).

The copper alloy material of the first embodiment of the present invention has a difference (δ1-δ2) between elongation (δ1) before heat treatment (A1) and elongation (δ2) after heat treatment (A1) of 0 to 10%, preferably It is made of 0-5% copper alloy.

The elongation (δ) of the copper alloy material of the first embodiment of the present invention is preferably 20% or more, particularly preferably 30% or more. Note that the elongation (δ) of the copper alloy material in the first embodiment of the present invention refers to the elongation of the copper alloy material after heat treatment (A1).

In the copper alloy material of the first embodiment of the present invention, the copper alloy has been subjected to solution treatment for making the copper alloy into a solution and heat treatment (A1) for heating at 225°C ± 100°C after the solution treatment, It is a copper alloy containing Cu-Ni-P precipitates, in which all or part of the precipitates have a composition of Ni ₁₂ P ₅ .

In addition, in the copper alloy material of the first embodiment of the present invention, after the solution treatment for making the copper alloy into a solution is performed, the heat treatment (A1) of heating at 225°C ± 100°C is performed to improve the copper alloy material. Since precipitates having a composition of Ni ₁₂ P ₅ can be precipitated in the alloy, the difference between the elongation (δ1) before heat treatment (A1) and the elongation (δ2) after heat treatment (A1) (δ1-δ2) However, the difference (σ2) between the tensile strength (σ2) after heat treatment (A1) and the tensile strength (σ1) before heat treatment (A1) is maintained while elongation is maintained at 0 to 10%, preferably 0 to 5%. -σ1) is 20 MPa or more, preferably 30 MPa or more, particularly preferably 40 MPa or more.

An example of manufacturing the copper alloy material of the first embodiment of the present invention will be described below. The manufacturing example of the copper alloy material according to the first embodiment of the present invention described below is an example for manufacturing the copper alloy material according to the first embodiment of the present invention. Copper alloy materials are not limited to those manufactured by the method shown below.

First, melting and casting are performed according to a conventional method, and 0.40 to 1.50 mass% of Ni, preferably 0.70 to 1.20 mass% of Ni, and 0.10 to 0.50 mass% of P are melted and cast. , preferably 0.20 to 0.40% by mass of P, and the balance is Cu and unavoidable impurities. After the lump is heated and homogenized, the homogenized copper alloy is hot-worked, and then the hot-worked copper alloy is cold-worked into the desired shape of the copper alloy material. do. Examples of hot working include hot rolling in the case of plate materials, and hot extrusion in the case of tube materials. Examples of cold working include cold rolling in the case of plate materials, and cold rolling, cold drawing, and rolling for forming inner grooves in the case of pipe materials.

In the manufacturing example of the copper alloy material according to the first embodiment of the present invention, solution treatment and heat treatment (A1) are performed during or after the hot working and cold working.

Regarding solution treatment, after hot working and before or after cold working, a solution treatment is performed in which the copper alloy is heated to 700 to 900°C, preferably 800 to 900°C, and then rapidly cooled. . The rapid cooling is performed, for example, by cooling the heated copper alloy with water. In addition, when cold working is performed multiple times, after hot working and before all cold working, between cold workings, or after all cold working, the copper alloy is heated to 700 to 900 After heating to a temperature of 800 to 900°C, preferably 800 to 900°C, solution treatment is performed by rapidly cooling. Further, after hot working, solution treatment can also be performed by rapidly cooling the hot worked copper alloy.

As for heat treatment (A1), after performing solution treatment, heat treatment (A1) of heating the copper alloy at 225° C.±100° C. is performed. The heating time in the heat treatment (A1) is preferably 10 to 1000 minutes, particularly preferably 30 to 600 minutes. In the present invention, after the solution treatment and before the heat treatment (A1), a "treatment or process that does not involve heating" and/or "a treatment or process that involves heating at a temperature exceeding 325°C" is performed. You can. In other words, in the present invention, performing heat treatment (A1) after solution treatment does not mean only that heat treatment (A1) is performed immediately after solution treatment; and heat treatment (A1), "a treatment or step that does not involve heating" and/or "a treatment or step that involves heating at a temperature exceeding 325° C." may be performed. Therefore, heat treatment (A1) may be performed immediately after solution treatment, or after solution treatment, "treatment or process that does not involve heating" and/or "temperature exceeding 325 ° C. The heat treatment (A1) may be performed after performing the "treatment or step of heating". In addition, after the solution treatment is performed and before the heat treatment (A1) is performed, the copper alloy may be heated to a temperature in the range of 125 to 325°C for a short period of time that does not affect the effects of the present invention. may be exposed. For example, if a treatment or process that involves heating at a temperature exceeding 325°C is performed after solution treatment and before heat treatment (A1) is performed, the temperature must be raised to a predetermined temperature. Therefore, it passes through a temperature range of 125 to 325°C, but it is acceptable as long as the time for passing through the temperature range of 125 to 325°C is short enough not to affect the effects of the present invention. Moreover, treatment or processing at a temperature of less than 125° C. may be performed between the solution treatment and the heat treatment (A1).

The copper alloy material according to the second embodiment of the present invention contains 0.40 to 1.50% by mass of Ni and 0.10 to 0.50% by mass of P, with the balance consisting of Cu and inevitable impurities. Made of copper alloy,
The copper alloy is subjected to a solution treatment in which the copper alloy is made into a solution, and after the solution treatment, a treatment in which the copper alloy is heated at 850±100°C and then cooled from the heating temperature to 300°C at an average cooling rate of 50°C/second or less ( B) and a heat treatment (A2) of heating at 225°C ± 100°C after the treatment (B),
The difference (σ2-σ1) between the tensile strength (σ2) after the heat treatment (A2) and the tensile strength (σ1) before the heat treatment (A2) is 30 MPa or more, and the elongation before the heat treatment (A) (δ1) and the elongation (δ2) after the heat treatment (A) (δ1-δ2) is 0 to 10%;
It is a copper alloy material characterized by:

While carrying out various processing and treatments of copper alloys, the present inventors discovered that copper alloys with a specific chemical composition, that is, 0.40 to 1.50% by mass of Ni, preferably 0.70 to 1.20% by mass, A copper alloy containing % by mass of Ni and 0.10 to 0.50% by mass of P, preferably 0.20 to 0.40% by mass of P is subjected to solution treatment, followed by heat treatment. , treatment (B) of heating at 850±100°C and then cooling from the heating temperature to 300°C at an average cooling rate of 50°C/sec or less, and heat treatment (B) of heating at 225°C ± 100°C after treatment (B). It has been found that by performing A2), precipitates having a composition of Ni ₁₂ P ₅ can be precipitated, and the strength of the copper alloy material can be improved by precipitation strengthening.

The copper alloy material according to the second embodiment of the present invention contains 0.40 to 1.50% by mass of Ni and 0.10 to 0.50% by mass of P, with the balance consisting of Cu and inevitable impurities. It is made of copper alloy. In the present invention, the content of Ni and P refers to the content of Ni and P in the copper alloy material after heat treatment (A2).

The Ni content of the copper alloy material of the second embodiment of the present invention is 0.40 to 1.50% by mass. When the copper alloy is heated at 850±100°C, cooled from the heating temperature to 300°C at an average cooling rate of 50°C/sec or less, and then further heated at 225°C±100°C, It is a component that forms a precipitate having a composition of Ni ₁₂ P ₅ by a compound with P in a copper alloy and improves the tensile strength. When the Ni content is within the above range, the tensile strength of the copper alloy material becomes high. On the other hand, if the Ni content exceeds the above range, the elongation will be low, and the workability, for example, the strength of bending in the case of plate materials, the hairpin bending work and expandability in the case of pipe materials, will be reduced. If the Ni content is less than the above range, the strength of the copper alloy material will be low. In particular, when the copper alloy material of the second form of the present invention is a pipe material, the Ni content of the copper alloy material of the second form of the present invention is 0, since the pipe material has high strength and excellent workability. It is preferably .70 to 1.20% by mass.

The P content of the copper alloy material of the second embodiment of the present invention is 0.10 to 0.50% by mass. P is when the copper alloy is heated at 850±100°C, cooled from the heating temperature to 300°C at an average cooling rate of 50°C/sec or less, and then further heated at 225°C±100°C. It is a component that forms a precipitate having a composition of Ni ₁₂ P ₅ by a compound with Ni in a copper alloy and improves the tensile strength. When the P content is within the above range, the tensile strength of the copper alloy material becomes high. On the other hand, if the P content exceeds the above range, workability may decrease and cracks may occur during hot working or cold working, and if the P content is below the above range, the amount of precipitates As a result, the strength of the copper alloy material decreases. In particular, when the copper alloy material of the second form of the present invention is a pipe material, the P content of the copper alloy material of the second form of the present invention is 0, since the pipe material has high strength and excellent workability. It is preferably .20 to 0.40% by mass.

The copper alloy material of the second form of the invention contains 0.40-1.50% by weight of Ni, preferably 0.70-1.20% by weight and 0.10-0.50% by weight of Ni. A copper alloy containing P, preferably 0.20 to 0.40% by mass of P, and the remainder consisting of Cu and unavoidable impurities, is solution treated, and after the solution treatment, heated at 850 ± 100 ° C., It is made of a copper alloy obtained by performing a treatment (B) of cooling from the heating temperature to 300°C at an average cooling rate of 50°C/second or less, and then a heat treatment (A2) of heating at 225°C ± 100°C. That is, the copper alloy material of the second embodiment of the present invention contains 0.40 to 1.50 mass% Ni, preferably 0.70 to 1.20 mass% Ni, and 0.10 to 0.50 mass% Ni. % of P, preferably 0.20 to 0.40 mass % of P, and the remainder is Cu and unavoidable impurities. In the process of obtaining a copper alloy material by performing hot working such as cold working, cold working such as cold rolling, cold drawing, etc., and various heat treatments, the copper alloy is heated at 700 to 900°C, preferably 800 to 900°C. A solution treatment of heating and rapid cooling is performed, and as a subsequent heat treatment, a treatment (B) of heating at 850 ± 100 ° C. and cooling from the heating temperature to 300 ° C. at an average cooling rate of 50 ° C. / second or less, Furthermore, it can be obtained by performing a heat treatment (A2) of heating at 225° C.±100° C. By setting the heating temperature and cooling rate of treatment (B) and the heat treatment temperature of heat treatment (A2) within the above ranges, the Cu-Ni-P system containing at least a part of precipitates having a composition of Ni ₁₂ P ₅ is formed. A precipitate of is obtained. On the other hand, if the heat treatment temperature in heat treatment (A2) is lower than the above range, precipitates having a composition of Ni ₁₂ P ₅ are difficult to precipitate, and even if the temperature exceeds the above range, precipitates having a composition of Ni ₁₂ P ₅ are difficult to precipitate. Precipitates are difficult to separate. Furthermore, if the heating temperature in treatment (B) was below the above range, sufficient time could not be secured for precipitation during the cooling process to 300°C, and if it exceeded the above range, the crystal grains would become too coarse. Becomes a crystalline structure. Furthermore, if the average cooling rate from the heating temperature after heating in treatment (B) to 300° C. exceeds the above range, the strength improvement effect of the heat treatment, that is, the value of “σ2−σ1” becomes small. In addition, when the copper alloy material of the second embodiment of the present invention is brazed with other members by brazing, the treatment (B) is performed by brazing heating during brazing and subsequent cooling. Good too.

The heating time in treatment (B) is preferably 10 to 1800 seconds, particularly preferably 10 to 180 seconds. When the heating time in treatment (B) is within the above range, the strength improvement effect becomes greater. On the other hand, if the heating time in treatment (B) is less than the above range, the material will not be heated sufficiently and the temperature will become uneven, causing variations in mechanical properties. The material tends to soften.

In treatment (B), after heating at 850±100°C, cooling is performed from the heating temperature to 300°C at an average cooling rate of 50°C/second or less. When the cooling rate is within the above range, the strength improving effect becomes greater. As a cooling method, for example, if the average cooling rate from the heating temperature to 300°C is 25 to 50°C/sec, cooling methods such as forced air cooling may be used, and if the average cooling rate from the heating temperature to 300°C is When the temperature is 20° C./second or less, cooling methods such as natural air cooling may be used.

The heat treatment time in heat treatment (A2) is preferably 10 to 2000 minutes, particularly preferably 30 to 1000 minutes. By setting the heat treatment time in heat treatment (A2) within the above range, a sufficient amount of precipitates having a composition of Ni ₁₂ P ₅ is precipitated to the extent that the strength improvement effect of the copper alloy material of the present invention can be obtained. be able to. On the other hand, if the heat treatment time in heat treatment (A2) is less than the above range, the amount of precipitates having the composition of Ni ₁₂ P ₅ tends to decrease, making it difficult to obtain the effect of improving the strength of the copper alloy material, and If the content exceeds the above range, the precipitates will become large and the strength of the copper alloy material will tend to decrease.

In the present invention, "solution treatment, treatment (B) after solution treatment, and heat treatment (A2) after treatment (B)" means that the copper alloy is subjected to solution treatment. It does not only mean that treatment (B) is applied immediately after treatment (B) and that heat treatment (A2) is applied immediately after treatment (B), but also that treatment (A2) is performed between solution treatment and treatment (B) or treatment. Between (B) and heat treatment (A2), "a treatment or step that does not involve heating" and/or "a treatment or step that involves heating at a temperature exceeding 325° C." may be performed. In other words, treatment (B) may be applied to the copper alloy immediately after solution treatment, and heat treatment (A2) may be applied immediately after treatment (B), or solution treatment may be applied to the copper alloy. After the treatment, a "treatment or step that does not involve heating" and/or a "treatment or step that involves heating at a temperature exceeding 325°C" may be performed, and then treatment (B) may be performed, or the treatment (B) may be performed. Even if heat treatment (A2) is performed after (B) is applied, a "treatment or process that does not involve heating" and/or "a treatment or process that involves heating at a temperature exceeding 325°C" is performed. good. In addition, after the solution treatment is applied and before the treatment (B) is applied, or after the treatment (B) is applied and before the heat treatment (A2) is applied, the main The copper alloy may be exposed to temperatures in the range of 125 to 325° C. for a short period of time without affecting the effects of the invention. For example, if a treatment or process that involves heating at a temperature exceeding 325°C is performed after the treatment (B) is performed and before the heat treatment (A2) is performed, the temperature must be raised to a predetermined temperature. Therefore, the temperature range of 125 to 325° C. is passed through, but it is acceptable as long as the time for passing through the temperature range of 125 to 325° C. is short enough not to affect the effects of the present invention. Further, treatment or processing at a temperature of less than 125° C. may be performed between the solution treatment and treatment (B) or between treatment (B) and heat treatment (A2).

The copper alloy material of the second embodiment of the present invention has a difference (σ2-σ1) between the tensile strength (σ2) after heat treatment (A2) and the tensile strength (σ1) before treatment (B) of 30 MPa or more, It is preferably made of a copper alloy having a pressure of 40 MPa or more, particularly preferably 50 MPa or more.

The tensile strength (σ) of the copper alloy material according to the second embodiment of the present invention is preferably 200 to 280 MPa, particularly preferably 240 to 280 MPa. Note that the tensile strength (σ) of the copper alloy material according to the second embodiment of the present invention refers to the tensile strength of the copper alloy material after heat treatment (A2).

The copper alloy material of the second embodiment of the present invention has a difference (δ1-δ2) between elongation (δ1) before treatment (B) and elongation (δ2) after heat treatment (A2) of 0 to 10%, preferably It is made of 0-5% copper alloy.

The elongation (δ) of the copper alloy material according to the second embodiment of the present invention is preferably 20% or more, particularly preferably 30% or more. Note that the elongation (δ) of the copper alloy material in the second embodiment of the present invention refers to the elongation of the copper alloy material after heat treatment (A2).

In the copper alloy material of the second embodiment of the present invention, the copper alloy is subjected to solution treatment, and after heating at 850 ± 100 °C after the solution treatment, from the heating temperature to 300 °C, 50 °C / seconds or less The copper alloy subjected to treatment (B) of cooling at an average cooling rate and heat treatment (A2) of heating at 225 ° C ± 100 ° C after treatment (B) contains Cu-Ni-P precipitates. , is a copper alloy in which all or part of the precipitates are precipitates having a composition of Ni ₁₂ P ₅ .

In addition, in the copper alloy material of the second embodiment of the present invention, after the copper alloy is subjected to solution treatment, after being heated at 850±100°C, from the heating temperature to 300°C at 50°C/sec. The composition of Ni ₁₂ P ₅ is added to the copper alloy by performing cooling treatment (B) at the following average cooling rate and heat treatment (A2) of heating at 225°C ± 100°C after treatment (B). Therefore, the difference (δ1-δ2) between the elongation (δ1) before treatment (B) and the elongation (δ2) after heat treatment (A2) is 0 to 10%, preferably 0 to 10%. The difference (σ2-σ1) between the tensile strength (σ2) after heat treatment (A2) and the tensile strength (σ1) before treatment (B) is 30 MPa or more, preferably 40 MPa, while maintaining the elongation at 5%. Above, it is especially preferably 50 MPa or more.

An example of manufacturing the copper alloy material according to the second embodiment of the present invention will be described below. The manufacturing example of the copper alloy material according to the second embodiment of the present invention described below is an example for manufacturing the copper alloy material according to the second embodiment of the present invention. Copper alloy materials are not limited to those manufactured by the method shown below.

First, melting and casting are performed according to a conventional method, and 0.40 to 1.50 mass% of Ni, preferably 0.70 to 1.20 mass% of Ni, and 0.10 to 0.50 mass% of P are melted and cast. , preferably 0.20 to 0.40% by mass of P, and the balance is Cu and unavoidable impurities. After the lump is heated and homogenized, the homogenized copper alloy is hot-worked, and then the hot-worked copper alloy is cold-worked into the desired shape of the copper alloy material. do. Examples of hot working include hot rolling in the case of plate materials, and hot extrusion in the case of tube materials. Examples of cold working include cold rolling in the case of plate materials, and cold rolling, cold drawing, and rolling for forming inner grooves in the case of pipe materials.

In the manufacturing example of the copper alloy material according to the second embodiment of the present invention, solution treatment, treatment (B), and heat treatment (A2) are carried out during or after the hot working and cold working. conduct.

Regarding solution treatment, after hot working and before or after cold working, a solution treatment is performed in which the copper alloy is heated to 700 to 900°C, preferably 800 to 900°C, and then rapidly cooled. . The rapid cooling is performed, for example, by cooling the copper alloy with water. In addition, when cold working is performed multiple times, after hot working and before all cold working, between cold workings, or after all cold working, the copper alloy is heated to 700 to 900 After heating to 800-900°C, preferably 800 to 900°C, solution treatment is performed by rapidly cooling. Further, after hot working, solution treatment can also be performed by rapidly cooling the hot worked copper alloy.

Process (B) is a process in which after solution treatment, the copper alloy is heated at 850 ± 100 °C and then cooled from the heating temperature to 300 °C at an average cooling rate of 50 °C / second or less. I do. The heating time in treatment (B) is preferably 10 to 1800 seconds, particularly preferably 10 to 180 seconds. In treatment (B), after heating at 850±100°C, the cooling rate from the heating temperature to 300°C is 50°C/sec or less. As a cooling method, for example, if the average cooling rate from the heating temperature to 300°C is 25 to 50°C/sec, cooling methods such as forced air cooling may be used, and if the average cooling rate from the heating temperature to 300°C is When the temperature is 20° C./second or less, cooling methods such as natural air cooling may be used. When the copper alloy material of the second embodiment of the present invention is a pipe material, particularly when it is a heat exchanger for an air conditioner such as a room air conditioner or a package air conditioner, or a heat exchanger tube or refrigerant piping for a refrigerator etc., it is a heat exchanger for an air conditioner. Alternatively, refrigerators and the like are manufactured by assembling the tube material with other members and then brazing the tube material and other members, but this brazing heating is performed in accordance with the second aspect of the present invention. It is good also as processing (B) concerning a copper alloy material of the form. That is, 0.40 to 1.50% by weight of Ni, preferably 0.70 to 1.20% by weight Ni, and 0.10 to 0.50% by weight of P, preferably 0.20 to 0.40% by weight. An ingot, which is a copper alloy containing % by mass of P and the remainder consisting of Cu and inevitable impurities, was hot worked and cold worked into the shape of a pipe material, and solution treatment was performed. The pipe material is assembled with other members constituting an air conditioner heat exchanger or refrigerator, and then heated at 850°C ± 100°C, and then heated from the heating temperature to 300°C at an average cooling rate of 50°C/second or less. It is also possible to perform the treatment (B) by cooling and brazing the tube material and other members to obtain a copper alloy material before heat treatment (A2). In the present invention, after performing the solution treatment and before performing the treatment (B), a "treatment or process that does not involve heating" and/or "a treatment or process that involves heating at a temperature exceeding 325°C" is performed. Good too. In other words, in the present invention, performing treatment (B) after solution treatment does not mean only that treatment (B) is performed immediately after solution treatment; and treatment (B), a "treatment or step that does not involve heating" and/or "a treatment or step that is heated at a temperature exceeding 325° C." may be performed. Therefore, treatment (B) may be performed immediately after solution treatment, or after solution treatment, "treatment or process that does not involve heating" and/or "temperature exceeding 325 ° C. The treatment (B) may be performed after performing the "treatment or step of heating". In addition, after the solution treatment is performed and before the treatment (B) is performed, the copper alloy may be heated to a temperature in the range of 125 to 325°C for a short period of time that does not affect the effects of the present invention. may be exposed. For example, if a treatment or process that involves heating at a temperature higher than 325°C is performed after solution treatment and before treatment (B) is applied, the temperature should not be increased to a predetermined temperature. Therefore, it passes through a temperature range of 125 to 325°C, but it is acceptable as long as the time for passing through the temperature range of 125 to 325°C is short enough not to affect the effects of the present invention. Moreover, treatment or processing at a temperature of less than 125° C. may be performed between the solution treatment and treatment (B).

Regarding the heat treatment (A2), after the treatment (B) is performed, a heat treatment (A2) is performed in which the copper alloy is heated at 225° C.±100° C. The heating time in the heat treatment (A2) is preferably 10 to 2000 minutes, particularly preferably 30 to 1000 minutes. In addition, even if "a treatment or process that does not involve heating" and/or "a treatment or process that involves heating at a temperature exceeding 325°C" is performed after performing treatment (B) and before performing heat treatment (A2), good. In other words, in the present invention, performing the heat treatment (A2) after the treatment (B) does not mean only that the heat treatment (A2) is performed immediately after the treatment (B); Between (B) and heat treatment (A2), "a treatment or step that does not involve heating" and/or "a treatment or step that involves heating at a temperature exceeding 325° C." may be performed. Therefore, heat treatment (A2) may be performed immediately after treatment (B), or after treatment (B), "treatment or process that does not involve heating" and/or "325 ° C. The heat treatment (A2) may be performed after performing "a treatment or step of heating at a temperature exceeding 100%." When treatment (B) is performed by brazing heating, heat treatment (A2) is performed by heating the brazed body in which the copper alloy tube material and other members are brazed at 225 ° C ± 100 ° C. conduct. In addition, after the treatment (B) is performed and before the heat treatment (A2) is performed, the copper may be heated to a temperature in the range of 125 to 325°C for a short period of time that does not affect the effects of the present invention. The alloy may be exposed. For example, if a treatment or process that involves heating at a temperature exceeding 325°C is performed after the treatment (B) is performed and before the heat treatment (A2) is performed, the temperature must be raised to a predetermined temperature. Therefore, the temperature range of 125 to 325° C. is passed through, but it is acceptable as long as the time for passing through the temperature range of 125 to 325° C. is short enough not to affect the effects of the present invention. Moreover, treatment or processing at a temperature of less than 125° C. may be performed between the treatment (B) and the heat treatment (A2).

Copper alloy material obtained by performing solution treatment and heat treatment (A1) on the copper alloy material according to the first embodiment of the present invention, and solution treatment and treatment (B) on the copper alloy material according to the second embodiment of the present invention The copper alloy material obtained by heat treatment (A2) contains 0.40 to 1.50% by mass of Ni and 0.10 to 0.50% by mass of P, with the balance being Cu and unavoidable impurities. The copper alloy forming the copper alloy material contains Ni ₁₂ P ₅ as a precipitate.

That is, the copper alloy material of the third embodiment of the present invention contains 0.40 to 1.50% by mass of Ni and 0.10 to 0.50% by mass of P, with the remainder being Cu and unavoidable impurities. It is made of a copper alloy consisting of
The copper alloy is a copper alloy material characterized in that it contains precipitates, and all or part of the precipitates are Ni ₁₂ P ₅ .

The Ni content of the copper alloy material according to the third embodiment of the present invention is 0.40 to 1.50% by mass, preferably 0.70 to 1.20% by mass. When the Ni content is within the above range, the tensile strength of the copper alloy material becomes high. On the other hand, if the Ni content exceeds the above range, the elongation will be low, and the workability, for example, the strength of bending in the case of plate materials, the hairpin bending work and expandability in the case of pipe materials, will be reduced. If the Ni content is less than the above range, the strength of the copper alloy material will be low.

The P content of the copper alloy material of the third embodiment of the present invention is 0.10 to 0.50% by mass, preferably 0.20 to 0.40% by mass. When the P content is within the above range, the tensile strength of the copper alloy material becomes high. On the other hand, if the P content exceeds the above range, workability may decrease and cracks may occur during hot working or cold working, and if the P content is below the above range, the amount of precipitates As a result, the strength of the copper alloy material decreases.

The copper alloy forming the copper alloy material of the third embodiment of the present invention contains precipitates. All or part of the precipitates in the copper alloy forming the copper alloy material of the third embodiment of the present invention are Ni ₁₂ P ₅ . In the present invention, it is confirmed that the copper alloy contains precipitates having a composition represented by Ni ₁₂ P ₅ by analyzing the copper alloy using the following analysis method. Copper alloy material is cut to a thickness of about 0.5 mm using a fine cutter and a micro cutter, and then mechanically polished to a thickness of 0.2 mm using a rotary polisher and water-resistant abrasive paper No. 400 to 1200. This thin film sample was formed into a circle with a diameter of 3 mm, and then electrolytically polished under the following conditions. Using a solution diluted with methyl alcohol so that the nitric acid concentration is 30% by weight as an electrolytic polishing solution, the sample is jet-polished at a solution temperature of about -30°C. Tenupol III manufactured by STRUERS is used as the jet electropolishing device. Immediately after electrolytic polishing, the sample is observed under TEM. For TEM observation, JEOL-2100F (acceleration voltage 200 kV) manufactured by JEOL is used. During observation, the crystal orientation is adjusted using a two-axis sample tilting mechanism so that the incidence is from the 100 or 110 crystal band. Observations include a bright-field image with transmitted waves entering the objective aperture, a dark-field image with diffracted waves entering the objective aperture, and a selected-area diffraction image. The exposure time is about 0.5 seconds for bright field images, and about 5 seconds for dark field images and selected area diffraction images.

The copper alloy material of the third embodiment of the present invention is a copper alloy that has been subjected to a solution treatment to make the copper alloy a solution, and a heat treatment (A1) in which the copper alloy is heated at 225°C ± 100°C after the solution treatment, or solution treatment of solutionizing the copper alloy, and after the solution treatment, heating at 850 ± 100 ° C. and cooling from the heating temperature to 300 ° C. at an average cooling rate of 50 ° C. / second or less (B); This is a copper alloy that has been subjected to heat treatment (A2) of heating at 225° C.±100° C. after treatment (B).

The tensile strength (σ) of the copper alloy material according to the third embodiment of the present invention is preferably 200 to 280 MPa, particularly preferably 240 to 280 MPa. Further, the elongation (δ) of the copper alloy material according to the third embodiment of the present invention is preferably 20% or more, particularly preferably 30% or more.

The copper alloy material of the present invention, that is, the copper alloy material of the first embodiment of the present invention, the copper alloy material of the second embodiment of the present invention, and the copper alloy material of the third embodiment of the present invention, can be heated at 225°C ± 100°C. Since it is a copper alloy material that can be obtained through heat treatment at low temperatures of ℃, manufacturing costs can be reduced.

The copper alloy material of the present invention, that is, the copper alloy material of the first embodiment of the present invention, the copper alloy material of the second embodiment of the present invention, and the copper alloy material of the third embodiment of the present invention, include plate materials, rods, etc. materials, pipe materials, especially seamless pipes, etc. When the copper alloy material of the present invention is a pipe material, the copper alloy material of the present invention is suitably used as a heat exchanger for an air conditioner such as a room air conditioner or a package air conditioner, or a heat transfer tube or refrigerant pipe for a refrigerator. Further, the tube material made of the copper alloy material of the present invention includes a bare tube without a groove on the inner surface and an inner grooved tube having a groove on the inner surface. Further, when the copper alloy material of the present invention is a plate material, the copper alloy material of the present invention is suitably used for various uses that require strong processing, that is, as a copper alloy plate material for strong processing.

(Example and comparative example)
(1) The copper alloy ingots shown in Table 1 were melted and cast to produce billets for hot extrusion.
(2) The above billet was heated and hot extruded at 850°C to obtain an extruded blank tube. Next, the hot extruded raw tube was extruded into water and rapidly cooled.
・Before extrusion, a hole with an inner diameter of approximately 75 mm was made while hot.
- The outer diameter of the extruded raw tube was 102 mm, and the inner diameter was 75 mm.
(3) The extruded mother pipe was cold rolled using a Birger mill to obtain a rolled mother pipe.
- The outer diameter of the rolled blank pipe was 46 mm, and the inner diameter was 39.8 mm.
- The degree of working (reduction in area) in cold rolling was 88.9%.
Section reduction rate (%) = ((cross-sectional area before processing - cross-sectional area after processing) / cross-sectional area before processing) x 100
(4) The above-mentioned rolled blank pipe was cold drawn several times to obtain a drawn blank pipe.
- The outer diameter of the drawn blank tube was 38 mm, and the inner diameter was 33 mm.
- The degree of working in the entire cold drawing was 96.6% in terms of area reduction rate.
- The total degree of work of cold rolling and cold drawing, that is, the total degree of work of cold working, was 99.8% in area reduction rate.
(5) The drawn raw pipe described above was subjected to intermediate annealing to obtain a raw pipe to be subjected to a rolling process.
- Intermediate annealing was carried out at a holding temperature of 550°C.
(6) The above raw tube was subjected to ball rolling processing to obtain an internally grooved copper alloy tube a.
<Dimensions of internally grooved copper alloy tube a>
・Outer diameter: 7.0mm
・Bottom thickness: 0.30mm
・Fin height: 0.22mm
・Fin vertex angle: 13°
・Number of grooves: 44 ・Lead angle θ: 24°
(7) The above internally grooved tube was subjected to the treatments shown in Table 1 in the order shown in the table to obtain an internally grooved copper alloy tube b.
(8) The tensile strength (σ) and elongation (δ) of the copper alloy tubes after the treatment shown in Table 1 were measured. The results are shown in Table 1. Further, the copper alloy precipitates forming the obtained internally grooved copper alloy tube b were analyzed. The results are shown in Table 1.
<Processing>
- Processing p: After heating at 850°C for 1800 seconds, water cooling is performed.
- Processing q: After heating at 225°C for 10,000 seconds, air cooling is performed.
- Process r: After heating at 850°C for 30 seconds, air cooling is performed.
- Processing s: After heating at 500°C for 1000 seconds, air cooling is performed.
In the above air cooling, the average cooling rate from the heating temperature to 300°C is 2 to 20°C/sec.
<Tensile strength (σ), elongation (δ)>
The tensile strength (σ) and elongation (δ) of the copper alloy were measured in accordance with JIS Z2241.
<Analysis of precipitates>
The copper alloy material was cut to a thickness of about 0.5 mm using a fine cutter and a micro cutter, and then mechanically polished to a thickness of 0.2 mm using a rotary polisher and water-resistant abrasive paper No. 400 to 1200. This thin film sample was formed into a circular shape with a diameter of 3 mm, and then electrolytically polished under the following conditions. Using a solution diluted with methyl alcohol so that the nitric acid concentration was 30% by weight as an electrolytic polishing solution, the sample was jet polished at a solution temperature of about -30°C. Tenupol III manufactured by STRUERS was used as a jet electropolishing device. Immediately after electrolytic polishing, the sample was observed under TEM. For TEM observation, JEOL-2100F (acceleration voltage 200 kV) manufactured by JEOL was used. During observation, the crystal orientation was adjusted using a two-axis sample tilting mechanism so that the incidence was from the 100 or 110 crystal band. Observations include a bright-field image with transmitted waves entering the objective aperture, a dark-field image with diffracted waves entering the objective aperture, and a selected-area diffraction image. The exposure time is about 0.5 seconds for bright field images, and about 5 seconds for dark field images and selected area diffraction images.

Claims (4)

A casting process is carried out to obtain a copper alloy ingot containing 0.40 to 1.50 mass% of Ni and 0.10 to 0.50 mass% of P, with the balance consisting of Cu and unavoidable impurities. , after heating and homogenizing the copper alloy ingot, hot working the homogenized copper alloy, and then cold working the hot worked copper alloy seamless copper alloy. A method of manufacturing tubes,
During the period from the hot working to the cold working or after the cold working, a solution treatment is performed, and after the solution treatment, a heat treatment (A1) of heating at 225 ° C ± 100 ° C is performed,
In the heat treatment (A1), the difference (σ2-σ1) between the tensile strength (σ2) after the heat treatment (A1) and the tensile strength (σ1) before the heat treatment (A1) is 20 MPa or more, and the heat treatment (A1) The difference (δ1-δ2) between the elongation before (δ1) and the elongation (δ2) after the heat treatment (A1) is 0 to 10% ;
A method for manufacturing a copper alloy seamless pipe characterized by: A casting process is carried out to obtain a copper alloy ingot containing 0.40 to 1.50 mass% of Ni and 0.10 to 0.50 mass% of P, with the balance consisting of Cu and unavoidable impurities. , after heating and homogenizing the copper alloy ingot, hot working the homogenized copper alloy, and then cold working the hot worked copper alloy seamless copper alloy. A method of manufacturing tubes,
Solution treatment is performed during or after the cold working from the hot working to the cold working, and after the solution treatment, heating at 850 ± 100°C, and then heating at 50°C from the heating temperature to 300°C. A process (B) of cooling at an average cooling rate of /second or less is performed, and after the process (B), a heat treatment (A2) of heating at 225 ° C ± 100 ° C is performed,
In the treatment (B) and the heat treatment (A2), the difference (σ2-σ1) between the tensile strength (σ2) after the heat treatment (A2) and the tensile strength (σ1) before the treatment (B) is 30 MPa or more. and the difference (δ1-δ2) between the elongation (δ1) before the treatment (B) and the elongation (δ2) after the heat treatment (A2) is 0 to 10% ;
A method for manufacturing a copper alloy seamless pipe characterized by: 3. The method for manufacturing a _seamless copper alloy pipe according to claim 1, wherein the copper alloy contains precipitates, and all or part of the precipitates are _Ni12P5 . A method for producing a heat exchanger, the method comprising obtaining a heat exchanger using a copper alloy seamless tube obtained by carrying out the method for producing a copper alloy seamless tube according to any one of claims 1 to 3 .