JP4489701B2 - Copper base alloy - Google Patents

Description

  The present invention relates to a copper-based alloy suitable for water pipe equipment such as valves, cocks and joints, for example, and relates to a copper-based alloy which has improved mechanical properties at high temperatures, particularly reduced tensile strength.

  In general, the bronze casting (CAC406) is excellent in castability, corrosion resistance, machinability, pressure resistance, and has a good hot water flow at the time of melting. It is also widely used for plumbing equipment for waterworks such as valves, cocks and joints.

However, recently, Pb (lead) contained in bronze has become a major social problem because it adversely affects the human body, and the amount of Pb leached into tap water is being severely regulated worldwide.
Therefore, based on such a situation, development of a new useful Pb-less copper alloy is urgently required, and various materials such as Bi-based, Bi-Sb-based, and Bi-Se-based materials have been developed. .

  For example, Japanese Patent Publication No. 5-63536 proposes a lead-less copper alloy in which Bi is added instead of lead in the copper alloy to improve machinability and prevent dezincing.

  Japanese Patent No. 2889829 proposes lead-free bronze in which the generation of porosity due to the addition of Bi for improving the machinability is suppressed by the addition of Sb and the mechanical strength is increased.

  Furthermore, US Pat. No. 5,614,038 proposes a bronze alloy in which, by adding Se and Bi, a Zn—Se compound is precipitated, and mechanical properties, machinability and castability are substantially equivalent to those of CAC406. .

  In many cases, these Pb-less copper alloys are manufactured in common with the production of the conventional CAC406 and the casting equipment at the time of mass production. In such a case, it is conceivable that Pb is mixed from a furnace, a ladle or the like.

  The Pb-less copper alloy is manufactured by using commercially available ingots and recycled materials such as scrap in consideration of cost and the environment. However, Pb as an inevitable impurity can be avoided in these materials. Absent.

Therefore, the Pb-less copper alloy is currently allowed to contain 0.4 mass % or less of Pb at an inevitable impurity level even if the casting equipment is dedicated to the Pb-less copper alloy.
Japanese Patent Publication No. 5-63536 Japanese Patent No. 2889829 US Pat. No. 5,614,038

  As described in Japanese Patent Publication No. 5-63536, Japanese Patent No. 2889829, and US Pat. No. 5,614,038, Pb-less bronze castings containing Bi as an alternative element for Pb contain a small amount of Pb as described above. If the casting material is exposed to a high temperature exceeding 100 ° C., the mechanical properties, particularly the tensile strength, may be lowered.

  This is because, as an alternative component of Pb, when a Pb-less bronze casting containing Bi is contained even in a small amount, Bi and Pb that do not form a solid solution in Cu are crystallized as a Bi-Pb binary eutectic having a low melting point. This is because it exists in the grain boundaries and in the crystal grains, and this becomes a locally weak part at high temperature, and the tensile strength decreases.

  Here, the eutectic is a structure formed by simultaneously crystallizing α and β crystals from the melt. The crystal grains are very fine and α and β are mixed.

  The decrease in tensile strength does not affect the actual use of plumbing equipment for water supply, but the market demands the supply of Pb-less bronze castings that can obtain mechanical properties closer to those of CAC406.

  The present invention has been developed in view of the above circumstances, and its object is to form an alloy or an intermetallic compound with Bi or Pb alone or in combination with each other in an alloy structure. Accordingly, it is an object of the present invention to provide a Pb-less copper-based alloy that improves the decrease in tensile strength at high temperatures and has mechanical properties closer to those of CAC406.

In order to achieve the above object, the present invention provides Sn 2.8 to 6.0 (mass%), Zn 1.0 to 12.0 (mass%), Bi 0.1 to 3.0 (mass%), P0. It contains 01 to 0.5 (mass%), Te 0.01 to 1.0 (mass%), Pb 0.25 or less (mass%), consists of the balance Cu and inevitable impurities , and Bi- Pb binary in the alloy structure. by forming the system co Akirabutsu high melting point Pb-Te intermetallic compound than to suppress the generation of Bi-Pb2 ternary copolymer Akirabutsu in alloy structure and improves the tensile strength that put in a high temperature copper It is a base alloy.

In the said copper base alloy, it is a copper base alloy containing Se0.05-1.2 (mass%) .

  According to the present invention, Bi or Pb alone or in a state of being bonded to each other and an additive element forming an alloy or an intermetallic compound are added to suppress the generation of Bi-Pb binary eutectic in the alloy structure. Thus, it is possible to improve the mechanical properties at high temperatures, especially the decrease in tensile strength.

  In the copper-based alloy of the present invention, the significance of adding Bi and Pb, which are present alone or in a state of being bonded to each other, and additive elements that form an alloy or an intermetallic compound will be described.

  When Te which is an additive element is added to the alloy, a Pb—Te intermetallic compound (or alloy) is formed in the alloy structure, and the generation of Bi—Pb binary eutectic in the alloy structure is suppressed.

  This is because the inclusion of Te, which is an additive element, is faster than the Bi—Pb binary eutectic in the alloy solidification process than the Bi—Pb binary eutectic in the alloy structure. Pb—Te intermetallic compounds (or alloys) having a high content are formed, and Bi and Pb forming Bi—Pb binary eutectics in the alloy structure are reduced. As a result, the Bi—Pb binary system It suppresses the generation of crystallites and realizes improved mechanical properties at high temperatures.

  Particularly preferable copper-based alloys are Cu-Sn-Zn-Bi-based and Cu-Sn-Zn-Bi-Se-based copper-based alloys, and the copper-based alloys contain the following component elements. The form is adopted, and each component range and the reason will be specifically described in detail.

Sn: 2.8 to 6.0% by mass
It is contained in order to improve wear resistance and corrosion resistance by solid solution in the α phase and improvement of strength and hardness, and formation of a protective film of SnO ₂ . Sn is an element that decreases the machinability as the content increases in the practical component range. Therefore, it is necessary to secure the mechanical properties within a range that does not decrease the corrosion resistance while suppressing the content. As a more preferable range, paying attention to the characteristics of elongation that is easily affected by the Sn content, even if the casting conditions are slightly different, the range in which the elongation with the best characteristics around 4.0% by mass can be reliably obtained is 3 .5 to 4.5% by mass was found.

Zn: 1.0-12.0 mass %
It is effective as an element that improves hardness and mechanical properties, particularly elongation, without affecting the machinability. In consideration of the content of Se and additive elements such as Te that form an alloy or an intermetallic compound with Bi and Pb, the effective content for improving high temperature characteristics is 1.0% by mass or more. In addition, Zn suppresses generation of Sn oxides due to gas absorption into the molten metal, and is effective for the soundness of the molten metal. Therefore, the inclusion of 4.0% by mass or more is effective for exerting this effect. . More practically, it is desirable to contain 5.0% by mass or more from the viewpoint of compensating for the suppression of Bi and Se. On the other hand, since Zn has a high vapor pressure, it is desirable that the content be 12.0% by mass or less in consideration of ensuring the working environment and castability. Considering the economic efficiency, about 8.0% by mass is particularly optimal.

Bi: 0.1-3.0 mass %
Containing 0.1% by mass or more is effective for improving the machinability. It is effective to contain 0.6% by mass or more in order to enter the porosity generated in the casting product during the solidification process of casting, suppress the occurrence of casting defects such as shrinkage and ensure the soundness of the casting. . On the other hand, in order to ensure the required mechanical properties, it is effective to be 3.0% by mass or less, and in particular, it is 1.7% by mass or less while suppressing the content while reducing the mechanical properties. It is effective to ensure sufficient. Practically, it is preferable that 0.1 to 2.4% by mass of Bi is contained together with the content of Se, and about 1.3% by mass is optimal considering the optimal content of Se.

Se: 0.05-1.2 mass %
It exists as an intermetallic compound of Bi—Se, Zn—Se, and Cu—Se in the copper alloy, and is a component that contributes to ensuring the machinability and the soundness of the casting as in the case of Bi. Therefore, the inclusion of Se is effective for the mechanical properties and the soundness of the casting while suppressing the Bi content. The upper limit of the content was set to 1.2% by mass from the viewpoint of economy. Further, Se contributes to securing the soundness of the casting even if contained in a trace amount, but in order to reliably obtain the action, the content of 0.05% by mass or more is effective, and this value is set as the lower limit. In particular, about 0.2% by mass is optimal.

Te: 0.01-1.0 mass %
Te is a component that improves the machinability by being dispersed without dissolving in the matrix. However, the effect of improving the machinability by Te is not exhibited at less than 0.01% by mass . Further, in order to crystallize the intermetallic compound TePb (melting point: about 917 ° C.) and suppress the generation of Bi—Pb binary eutectic, the content is preferably 0.05% by mass or more, but 1.0% by mass. Containing more than 1% is not economical and does not improve the decrease in tensile strength commensurate with the content. From these points, the content of Te is set to 0.01 to 1.0% by mass , preferably 0.05 to 0.5% by mass .

P: 0.01 to 0.5% by mass
It contains 0.01-0.5 mass % for the purpose of promoting deoxidation of a molten metal and producing a sound casting. Excessive inclusion tends to lower the solidus and cause segregation. When P is added as a deoxidizer, the P content in the alloy is usually 0.015-0.03% by mass , but it has a higher melting point than the Bi-Pb binary eutectic (melting point: about 125 ° C.). In order to crystallize the intermetallic compound Pb ₃ P ₂ , suppress the formation of Bi—Pb _binary eutectic, and improve the decrease in tensile strength at high temperatures, 0.05 to 0.1 mass % Content is preferred.

Pb: 0.25% by mass or less Pb may be contained in an impurity level of 0.3 to 0.4% by mass , so the range of inevitable impurities not actively containing Pb is 0.25% by mass or less. did.

In addition to Te described above, in the copper-based alloy of the present invention, the additive elements contained for the purpose of suppressing the generation of Bi-Pb binary eutectic are Te, P, Zr, Ti, Co, In, One or more types can be selected from the group consisting of Ca, B, Misch metal, and the like, and the content is preferably 0.01 to 1.0% by mass .

  By containing the above additive element, Bi-Pb binary eutectic has a higher melting point than Bi-Pb binary eutectic before the Bi-Pb binary eutectic crystallizes in the alloy structure in the solidification process of the casting. An intermetallic compound (or alloy), a Pb-M intermetallic compound (or alloy), or a Bi-Pb-M intermetallic compound (or alloy) is formed, and a Bi-Pb binary eutectic is formed in the alloy structure. This is because Bi and Pb to be formed are reduced, thereby suppressing the generation of Bi-Pb binary eutectic.

In addition, said M is said additive element, As mentioned above, the mechanical property under high temperature is improved by suppressing generation | occurrence | production of Bi-Pb binary eutectic. Moreover, also about the copper base alloy containing 0.05-0.5 mass % of Sb, generation | occurrence | production of Bi-Pb binary system eutectic is suppressed by adding the said additional element, and the effect of a high temperature characteristic improvement is effective. is there. In addition, Fe (0.3 mass % or less), Al (0.01 mass % or less), Si (0.01 mass % or less) are mentioned as an inevitable impurity in the copper base alloy of this invention.

Ten lead tests of Cu-Sn-Zn-Bi-Se-based and Cu-Sn-Zn-Bi-based bronze castings containing Te and Zr as additive elements among the lead-less copper-based alloys in the present invention were conducted, and the test results Will be explained. The tensile test is performed using an Amsler tensile tester using a CO ₂ mold at a casting temperature of 1130 ° C., cast into JIS A plan, and then using a No. 4 test piece as specified in JIS Z2201 manufactured by cutting. It was. In addition, a tensile test is performed by each sample n = 4, and a test result is the average value.

  The tensile test was performed under the following three conditions.

(Test 1)
Te content: 0.04 to 1.48% by mass (invention), test temperature: room temperature (22 ° C.), 100 ° C. and 150 ° C. The composition of the sample is shown in Table 1. In Test 1, the effect of containing Te is confirmed.

(Test 2)
Te content: 0.04 to 0.17 mass % (present invention), Se content: 0 to 1.2 mass %, test temperature: 150 ° C. The composition of the sample is shown in Table 2. In Test 2, the effect of the Te content is confirmed with a sample in which the Se content is changed.

(Test 3)
Te content: 0.09 to 0.22 mass % (invention), Se content: 0 to 0.83 mass %, Zn content: 1.02 to 8.53 mass %, test temperature: The temperature was 150 ° C. The composition of the sample is shown in Table 3. In this test 3, application to low Zn is confirmed.

The results of Test 1 are shown in Table 4 and FIG. From this result, it is standard 175 at 100 ° C. by containing Te 0.04 mass %, 0.11 mass %, 0.16 mass %, 0.50 mass %, 0.99 mass %, and 1.48 mass %. compared to .7N / mm ^2, respectively ^{198.3N / mm 2, 210.1N / mm} 2, 218.6N / mm 2, 215.9N / mm 2, 202.3N / mm 2, 197.7N / mm ² and has a tensile strength enhancing and also compared to a standard 155.4N / mm ² at 0.99 ° C., respectively ^{168.0N / mm 2, 185.5N / mm} 2, 209.7N / mm 2, 208. ^{5N / mm 2, 195.1N / mm} 2, 194.8N / mm 2 and tensile strength is improved. From this, by containing Te, it has sufficient tensile strength at room temperature, and can further improve the tensile strength at high temperature. However, since the content exceeding 1.0 mass % is not economical, the content is set to 1 mass % or less. As shown in Table 4 and FIG. 1, the tensile strength at a high temperature becomes the highest at 0.16% by mass of Te.

The results of Test 2 are shown in Table 5 and FIG. In addition, Se = 0, 0.2 mass %, 0.4 mass %, 0.6 mass %, and 1.2 mass % are all target values. From this result, when Se = 0, Sample No. containing Te, 0, 0.06 mass %, 0.11 mass %, and 0.14 mass % was contained. In 8,13,18,23, tensile strength, respectively ^{104.7N / mm 2, 109.1N / mm} 2, 118.9N / mm 2, 124.6N / mm 2 and tensile strength was slightly improved. When Se = 0.2, sample No. 1 containing Te, 0, 0.06 mass %, 0.10 mass %, and 0.14 mass % was used. In 9, 14, 19, and 24, the tensile strength is 150.0 N / mm ² , 150.7 N / mm ² , 161.8 N / mm ² , 167.3 N / mm ^2, and the tensile strength is higher than Se = 0. Improved. Similarly, when Se = 0.4, sample No. 1 containing Te, 0, 0.04 mass %, 0.12 mass %, and 0.15 mass % was used. 10, 15, 20, and 25, the tensile strengths are 146.7 N / mm ² , 148.2 N / mm ² , 185.5 N / mm ² , and 204.7 N / mm ² , respectively, and Se = 0.6 Sample No. 1 containing Te, 0, 0.05 mass %, 0.10 mass %, 0.17 mass %. In 11,16,21,26, respectively ^{159.6N / mm 2, 156.4N / mm} 2, 188.0N / mm 2, a 204.4N / mm ^2, when Se = 1.2, Te No. 0, 0.06% by mass , 0.11% by mass , and 0.15% by mass were added. 12, 17, 22, and 27 are 163.5 N / mm ² , 176.6 N / mm ² , 201.2 N / mm ² , and 215.3 N / mm ² , respectively, and the tensile increases as the Te content increases Strength improved. This indicates that the tensile strength at high temperature is improved by increasing the Se content in addition to the Te content.

In particular, as shown in FIG. 2, by containing 0.2% by mass of Se, the tensile strength at high temperature is improved by about 50% with respect to the specimen containing no Se at all, and Te is reduced to 0. By containing 05% by mass or more, the tensile strength at high temperature is further improved. As the Se content increases, the tensile strength at high temperatures also improves, but the increasing tendency becomes gradual. In this example, the upper limit of the content of Se is set to 1.2% by mass from the viewpoint of economy, but considering the improvement rate of tensile strength, it is preferable to set the upper limit to 0.4% by mass , In particular, 0.2% by mass is optimal.

The results of Test 3 are shown in Table 6 and FIGS. Incidentally, Zn = 2 wt%, 4 wt% and 8 wt%, Se = 0, 0.3 wt% and 0.6 wt% is aimed value none. From this result, the level of Zn = 2, when Se = 0, the Te 0,0.12 wt%, the sample contained 0.21 mass% No. 28-No. Tensile strength at 30, respectively ^{121.4N / mm 2, 150.7N / mm} 2, a 155.5N / mm ^2, when Se = 0.3, 0,0.10 wt% of Te, 0. Sample No. 21 containing 21% by mass 31-No. Tensile strength at 33 each ^{170.4N / mm 2, 198.7N / mm} 2, a 200.4N / mm ^2, when Se = 0.6, 0,0.09 wt% of Te, 0. Sample No. 22 containing 22% by mass 34-No. Tensile strength at 36, respectively ^{154.1N / mm 2, 198.0N / mm} 2, a 215.8N / mm ^2, Se, improved with the tensile strength to increase in the Te content. Further, even at the level of Zn = 4% by mass (sample No. 37 to No. 45) and 8% by mass (sample No. 46 to No. 54), similarly, when Se = 0, the tensile strength associated with the increase in Te content. improvement of is less than in the case of Se = 0.3 wt% and 0.6 wt%, in the case of Se = 0.3 wt% and 0.6 wt%, with Se, the increase in the Te content Tensile strength improved. This indicates that the tensile strength at high temperature is improved by increasing the Se content in addition to the Te content, as in Test 2. As shown in Table 6 and FIGS. 3 to 5, even if the Zn content is low, the effect of applying the present invention is obtained.

From tests on more than the inclusion of Te can improve the tensile strength at high temperatures, even by interaction with Se, it was found to be able to improve the tensile strength at high temperatures.

Next, a cutting test was performed in order to evaluate the cutting performance by adding Te.
The cutting test was performed on the conventional material, the present invention product containing Te, and CAC406. Chemical component values are shown in Table 7 .

  The cutting test conditions were a processing diameter of φ30, a feed amount of 0.2 mm / rev, a cutting amount of 3.0 mm, a rotation speed of 1800 rpm, a cutting speed of 170 m / min, and a cutting state dry. At the time, the cutting resistance of each sample was evaluated as a machinability index. The method for obtaining the machinability index is shown below.

Machinability index = (cutting resistance value of CAC406) / (cutting resistance value of each sample) × 100
The results of the machinability test are shown in Table 8 and FIG . From this result, the machinability index of the comparative example is 84.4, and the sample containing 0.51% by mass of Te is 95.1. By containing Te, the machinability is greatly improved.

Next, among the copper-based alloys in the present invention, an example including a test example of a Cu—Sn—Zn—Bi—Se bronze alloy containing P as an additive element, and Cu— containing Te as an additive element Examples including test examples of Sn—Zn—Bi—Se bronze alloys will be described.
The Cu-Sn-Zn-Bi- Se -based bronze alloy based, as an additive element, and bronze castings containing P 0.05-.09 wt%, and contained Te .1 to 0.21 wt% A bronze casting is prepared, a high-temperature Charpy impact test is performed on the bronze casting, and the test results are described. In addition, content of Pb contained in the said bronze casting was made into 0.2 mass % or less.

In the Charpy impact test, the test piece was cast at a casting temperature of 1130 ° C. using a CO ₂ mold, and then made into a No. 3 test piece as defined in JIS Z2202, and the tester used was a Charpy impact test as defined in JIS B7722. Machine (300J). In addition, an oil bath was used for the test, and the test piece was heated to 100 ° C. with high-temperature oil, held for 10 minutes, taken out from the oil bath, and a Charpy impact test was performed within 5 seconds.

Table 9 shows the chemical component value of each test piece. Table 10 shows that the impact value of the standard sample (Sample No. 64) is 100%, P is 0.05% by mass (Sample No. 62), 0. The impact value (vs. standard ratio) of the sample containing 09 mass % (sample No. 63) is shown. These sample Nos. 62-No. FIG . 7 shows a graph of 64 data.

Further, in Table 10 , a sample containing 0.1 mass % (sample No. 65) and 0.21 mass % (sample No. 66) of Te, assuming that the impact value of the standard sample (sample No. 67) is 100%. The impact value is shown. These sample Nos. 65-No. FIG . 8 shows a graph of 67 data.

As shown in FIG. 7 , when P is contained by 0.05 mass %, the impact value is improved by 126% compared to the standard sample, and when P is contained by 0.09 mass %, the impact value is 273 compared with the standard sample. % Improved. Therefore, it has been found that the impact value of the alloy improves with the inclusion of P.
Further, as shown in FIG. 8 , when Te is contained by 0.1% by mass , the impact value is improved by 175% compared to the standard sample, and when Te is contained by 0.21% by mass , the impact value is compared with the standard sample. Improved by 248%. Therefore, it was found that the impact value of the alloy is improved with the inclusion of Te, as is the case with the inclusion of P.

  As a result of the high-temperature impact test, when compared with the standard sample, the impact value was improved by an average of 200% for P and 212% for Te.

In addition, the area ratio of the Bi-Pb eutectic represented in the same table and the same figure is mentioned later.
Further, EDX quantitative analysis and mapping were performed on each test piece.

The mapping is to analyze where a specific element exists, and displays a portion where the element is concentrated in yellow. Each analysis was performed on the cut surface obtained by cutting the test piece after the Charpy impact test while avoiding the fracture surface. Shows a metal structure photograph of a new standard sample (Comparative Example) a (magnification 400 times) in FIG. 9 shows a mapping of each element in the metal structure photograph of FIG. 9 in FIG. 10.

The chemical component values of this standard sample (comparative example) are shown in Table 11 , and the EDX quantitative analysis results in regions 1 to 3 shown in the metal structure photograph of FIG. 9 are shown in Table 12 .

As is clear from FIG. 10 and Table 12, it is found from the standard sample mapping results shown in FIG. 10 that Bi and Pb coexist in region 1, and from the EDX quantitative analysis results shown in Table 12. , Bi and Pb were found to be concentrated in region 1 to form a Bi-Pb binary eutectic.

  Here, the alloy means a state in which two or more kinds of metal elements are melted in a solid state. Furthermore, an intermetallic compound refers to a compound formed by bonding two or more component metals in an alloy at a relatively simple atomic ratio.

Next, Sample No. containing 0.21% by mass of Te was used. 66 shows a metal structure photograph (magnification 400 times) of FIG. 11, and FIG . 12 shows mapping of each element in the metal structure photograph of FIG . Table 13 shows the results of quantitative EDX analysis in regions 1 to 5 shown in the metallographic photograph of FIG .

As is evident from Figure 12 and Table 13, the mapping results shown in FIG. 12, Te and Pb was found to coexist in the area 1, 3, 4, 5, EDX quantitative shown in Table 13 From the analysis results, it has been found that Te and Pb intensively form Te—Pb intermetallic compounds in the above-mentioned region, particularly in region 5.

  Further, in order to measure the area ratio of the Bi—Pb binary eutectic, a structure observation photograph was taken and analyzed by image analysis software.

  The area ratio refers to the ratio of the area occupied by the object (Bi-Pb binary eutectic phase) to the area of the visual field captured as an image.

  The Bi-Pb binary eutectic phase was identified by comparing EDX quantitative analysis results with metallographic photographs. The metal structure photograph was taken at a magnification of 400 times, and the area ratio was calculated as an average value of 20 fields for each sample.

Standard sample (Sample No. 64), Sample No. containing P 0.05% by mass 62 and the sample No. containing 0.09 mass % P. FIG . 13 shows tissue observation photographs (before image processing and after image processing) in which the area ratio of 63 is measured. Table 10 shows the results of measuring the area ratio of the Bi—Pb binary eutectic when P is added as an additive element.

Further, a standard sample (sample No. 67), a sample No. containing 0.1% by mass of Te. 65, and sample No. containing Te 0.21% by mass . FIG . 14 shows tissue observation photographs (before and after image processing) in which the area ratio of 66 is measured. Table 10 shows the results of measuring the area ratio of the Bi—Pb binary eutectic when Te is added as an additive element.

As shown in Table 10 , the area ratio of the Bi-Pb phase of the standard sample (Sample No. 64) is 0.268%, and the area ratio of the Bi-Pb phase when P is contained is P0.05 mass. % Containing 0.103% and P containing 0.09% by mass , 0.104%. These sample Nos. 62-No. FIG . 7 shows a graph of 64 data.

Further, as shown in Table 10, Bi-Pb-phase area ratio of the standard sample (Sample No.67) is 0.212% 0.052% in content Te0.1 wt%, containing Te0.21 wt% And 0.035%. These sample Nos. 65-No. FIG . 8 shows a graph of 67 data.

As shown in FIGS. 7 and 8 , it was found that the area ratio of the Bi—Pb phase was suppressed to 0.2% or less by containing P and Te as additive elements. In particular, it was found that when the generation of Bi—Pb binary eutectic is suppressed to 0.1% or less, the impact value is improved to about 130% compared to the standard sample.

  From the above-mentioned high temperature impact test, EDX quantitative analysis, mapping, and measurement of the area ratio of the Bi-Pb binary eutectic, by containing P and Te, P-Pb intermetallic compound, Te- It was found that high-temperature impact values were improved because Pb intermetallic compounds and the like were prepared to suppress the generation of Bi-Pb binary eutectics, and the melting points of these intermetallic compounds were high.

The copper-based alloy of the present invention is not limited to the above-described bronze alloy. Further, in the case of a brass alloy, for example, brass for hot forging, 59.0 to 62.0% by mass of Cu. , Sn 0.5 to 1.5 mass %, Bi 1.0 to 2.0 mass %, Se 0.03 to 0.20 mass %, Fe 0.05 to 0.20 mass %, P 0.05 to 0.10 mass % the containing component range, in the case of cutting a brass, Cu61.0～63.0 mass%, Sn0.3～0.7 wt%, Bi1.5～2.5 wt%, Se0.03～ 0.20 wt%, Fe0.1～0.30 wt%, is also applicable to leadless copper base alloys containing component range of P0.05~0.10 mass%.
Further, in the above embodiment, the addition of Te, P and other additive elements suppresses the generation of Bi—Pb binary eutectic in the alloy structure. The amount of return material such as scrap may be reduced, and the content of Pb may be suppressed by adjusting it to be lower than the upper limit of 0.2% by mass as an inevitable impurity.

The copper-based alloy of the present invention is used to process and mold water contact products such as valves, joints, pipes, faucets, water and hot water supplies, and to process and mold electrical and mechanical products such as gas appliances, washing machines and air conditioners. It is suitable for.

  Other members / parts suitable for the copper base alloy of the present invention are water contact parts such as valves and faucets, that is, ball valves, empty balls in ball valves, butterfly valves, gate valves, globes. Fittings such as valves, check valves, water faucets, water heaters and hot water flush toilet seats, water supply pipes, connection pipes and fittings, refrigerant pipes, electric water heater parts (casing, gas nozzle, pump parts, burners, etc.), strainers, water supply Meter parts, submersible sewage parts, drainage plugs, elbow pipes, bellows, toilet flanges, spindles, joints, headers, branch plugs, hose nipples, faucet fittings, stop cocks, water supply / drainage plugs, sanitary ware Fittings, shower hose connection fittings, gas appliances, building materials such as doors and knobs, home appliances, adapters for Saya pipe headers, automotive coolers , Fishing parts, microscope parts, water meter parts, meter parts, can be widely applied to railway pantograph components, other components and parts. Furthermore, toilet articles, kitchen articles, bathroom articles, toilet articles, furniture parts, living room articles, sprinkler parts, door parts, gate parts, vending machine parts, washing machine parts, air conditioner parts, gas welder parts Widely used in parts for heat exchangers, solar water heater parts, molds and parts, bearings, gears, parts for construction machinery, parts for railway vehicles, parts for transportation equipment, materials, intermediate products, final products and assemblies Applicable.

FIG. 1 is a graph showing the test results of tensile test 1.
FIG. 2 is a graph showing the test results of tensile test 2.
FIG. 3 is a graph showing the test results of tensile test 3.
FIG. 4 is a graph showing the test results of tensile test 3.
FIG. 5 is a graph showing the test results of tensile test 3.
FIG. 6 is a graph showing the test results of the machinability test.
FIG . 62-No. It is the graph which showed the Charpy impact test result of 64, and the Bi-Pb area ratio.
FIG . 65-No. It is the graph which showed the Charpy impact test result of 67, and the Bi-Pb area ratio.
FIG. 9 is a metallographic photograph (400 times magnification) of a standard sample (comparative example).
Figure 10 is a mapping of each element in the metal structure photograph of FIG. 9.
FIG. 11 shows a sample No. containing 0.21% by mass of Te. 66 is a metallographic photograph of 66 (400 times magnification).
Figure 12 is a mapping of each element in the metal structure photograph of Figure 11.
FIG. 13 shows Sample No. 62-No. It is the structure | tissue observation photograph (Before image processing and after image processing) which measured the area ratio of 64. FIG.
FIG. 14 shows sample no. 65-No. It is the structure | tissue observation photograph which measured the area ratio of 67 (before image processing and after image processing).

Claims (2)

Sn2.8-6.0 (mass%), Zn1.0-12.0 (mass%), Bi0.1-3.0 (mass%), P0.01-0.5 (mass%), Te0. Pb-Te metal containing 01-1.0 (mass%), Pb 0.25 or less (mass%), consisting of the balance Cu and inevitable impurities, and having a higher melting point than Bi-Pb binary eutectic in the alloy structure by forming between compounds, copper base alloy, characterized in that to suppress the generation of Bi-Pb2 ternary copolymer Akirabutsu in alloy structure and improves the tensile strength that put at a high temperature. The copper base alloy according to claim 1, wherein Se 0.05 to 1.2 (% by mass) is contained .

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