Forged lead-free copper alloy and method for producing the same

Abstract

The present invention discloses a forged lead-free copper alloy and a method for manufacturing the same. The alloy is composed of the following components in weight percentage: Cu content m Cu 57.0%≤m Cu ≤59.0%; Pb content m pb 0<m pb ≤0.1%; Al content m Al 0<m Al ≤0.05%; Sn content m Sn 0<m Sn ≤0.3%; Ni content m Ni 0<m Ni ≤0.3%; Fe content m Fe 0<m Fe ≤0.3%; the balance is Zn; the single impurity is ≤0.02%, and the total impurity does not exceed ≤0.2%. The invention provides an environmentally friendly lead-free brass alloy with low cost, excellent stress resistance, excellent forging performance, hot and cold forming performance and cutting performance.

Description

Technical Field

[0001] The invention relates to the technical field of copper alloy manufacturing, in particular to a forged lead-free copper alloy and a manufacturing method thereof. Background Art

[0002] Lead brass has been widely used in water supply systems to make faucets, various valves and other parts due to its excellent cutting performance, good mechanical properties and low cost. However, since lead brass will pollute the environment during production and use, and lead is easily leached in water, long-term drinking of tap water containing lead will seriously endanger human health, so its application is strictly controlled. The governments of the United States, Japan, Europe and other countries have legislated to gradually ban the use of lead-containing products in drinking water pipe fittings, and the US NSF / ANSI61-2008 drinking water standard stipulates that the lead content in water cannot exceed 2μg / L. At present, Europe has issued a plan to start the replacement and change of European drinking water materials, and Australia plans to implement new standard bills for existing materials at the same time. Clearly considering the implementation of the ultimate goal of Pb<0.1%, it is a necessary condition to enter the European and Australian markets. Require stricter control, implement new material standard requirements from 2026, require more stringent conditions, and require higher standards.

[0003] At present, existing research has been conducted to improve the cutting performance of copper alloys by replacing lead with bismuth, antimony or silicon, and to improve the corrosion resistance of the alloys by adding a certain amount of tin or nickel. Among them, the cutting performance of bismuth brass is closest to that of lead brass, but the existing bismuth brass adds a higher content of bismuth to make the cutting performance of the alloy close to that of lead brass, and at the same time adds a higher content of tin to improve the corrosion resistance of the alloy. Since the prices of bismuth and tin are both relatively expensive, the raw material cost of bismuth brass is relatively high. However, the corrosion resistance of tin is limited and cannot pass the 24-hour dezincification corrosion resistance test of copper chloride at a concentration of 1%. Summary of the invention

[0004] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0005] An object of the present invention is to provide a forged lead-free copper alloy and a method for manufacturing the same, which can provide an environmentally friendly lead-free brass alloy with low cost, excellent stress resistance, excellent forging performance, hot and cold forming performance and cutting performance.

[0006] In order to achieve these objects and other advantages according to the present invention, there is provided a forged lead-free copper alloy, which is composed of the following components in weight percentage: Cu content m Cu 57.0%≤m Cu ≤59.0%; Pb content m pb 0<m pb ≤0.1%; Al content mAl 0<m Al ≤0.05%; Sn content m Sn 0<m Sn ≤0.3%; Ni content m Ni 0<m Ni ≤0.3%; Fe content m Fe 0<m Fe ≤0.3%; the balance is Zn; individual impurities ≤0.02%, and the total impurities do not exceed ≤0.2%.

[0007] The present invention provides a method for manufacturing a forged lead-free copper alloy, comprising:

[0008] Step 1: Ingredients: The raw materials are composed of the following components in percentage by weight: Cu content m Cu 57.0%≤m Cu ≤59.0%; Pb content m pb 0<m pb ≤0.1%; Al content m Al 0<m Al ≤0.05%; Sn content m Sn 0<m Sn ≤0.3%; Ni content m Ni 0<m Ni ≤0.3%; Fe content m Fe 0<m Fe ≤0.3%; the balance is Zn; the single impurity is ≤0.02%, and the total impurities do not exceed ≤0.2%;

[0009] Step 2: smelting;

[0010] Step 3: horizontal continuous casting;

[0011] Step 4: Heating and forging.

[0012] Preferably, in the method for manufacturing the forged lead-free copper alloy, in the step three, the temperature of the horizontal continuous casting is 990-1080°C.

[0013] Preferably, in the method for manufacturing the forged lead-free copper alloy, the temperature of the heating forging is 680-780°C.

[0014] Preferably, in the method for manufacturing the forged lead-free copper alloy, in the step three, the horizontal continuous casting is a horizontal continuous casting rod to obtain a rod material, and after the horizontal continuous casting operation, the obtained rod material is also subjected to a peeling operation and then heated and forged.

[0015] Preferably, in the method for manufacturing the forged lead-free copper alloy, in the step three, the horizontal continuous casting is horizontal continuous casting of round ingots to obtain round ingots, and after the horizontal continuous casting operation, the obtained round ingots are also extruded to obtain rods, which are then heated and forged.

[0016] Preferably, in the method for producing the forged lead-free copper alloy, the temperature at which the obtained round ingot is extruded is 680-780°C.

[0017] The present invention has at least the following beneficial effects:

[0018] The forged lead-free copper alloy provided by the present invention does not contain toxic elements such as antimony, is an environmentally friendly alloy, has low harm to human body and environment, and its dissolution amount in water meets the NSF / ANSI61-2008 standard.

[0019] The forged lead-free copper alloy provided by the present invention has excellent mechanical properties, and can still pass a 4-hour ammonia test or a 24-hour ammonium chloride test (GB / T10567.2) without annealing to eliminate assembly stress, thereby ensuring compliance with the standards.

[0020] The forged lead-free copper alloy provided by the present invention has excellent use performance and process performance, and is particularly suitable for forging and turning to produce parts of drinking water supply systems, such as faucet products and various bathroom accessories.

[0021] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention provides a flow chart of a method for producing a forged lead-free copper alloy. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0024] The present invention provides a forged lead-free copper alloy, which is composed of the following components in weight percentage: Cu content m Cu 57.0%≤m Cu ≤59.0%; Pb content m pb 0<m pb ≤0.1%; Al content m Al 0<m Al ≤0.05%; Sn content m Sn 0<m Sn ≤0.3%; Ni content m Ni0<m Ni ≤0.3%; Fe content m Fe 0<m Fe ≤0.3%; the balance is Zn; individual impurities ≤0.02%, and the total impurities do not exceed ≤0.2%.

[0025] The forged lead-free copper alloy provided by the present invention does not contain toxic elements such as antimony, is an environmentally friendly alloy, has low harm to human body and environment, and its dissolution amount in water meets the NSF / ANSI61-2008 standard.

[0026] The forged lead-free copper alloy provided by the present invention has excellent mechanical properties, and can still pass a 4-hour ammonia test or a 24-hour ammonium chloride test (GB / T10567.2) without annealing to eliminate assembly stress, thereby ensuring compliance with the standards.

[0027] The forged lead-free copper alloy provided by the present invention has excellent use performance and process performance, and is particularly suitable for forging and turning to produce parts of drinking water supply systems, such as faucet products and various bathroom accessories.

[0028] The forged lead-free copper alloy provided by the present invention has excellent performance (mechanical properties, corrosion resistance) and process performance (cold and hot forming performance, cutting performance, welding performance, etc.), and is particularly suitable for forging and turning to produce parts for drinking water supply systems, such as faucet products and various bathroom accessories.

[0029] like Figure 1 As shown, the present invention provides a method for manufacturing a forged lead-free copper alloy, comprising:

[0030] Step 1: Ingredients: The raw materials are composed of the following components in percentage by weight: Cu content m Cu 57.0%≤m Cu ≤59.0%; Pb content m pb 0<m pb ≤0.1%; Al content m Al 0<m Al ≤0.05%; Sn content m Sn 0<m Sn ≤0.3%; Ni content m Ni 0<m Ni ≤0.3%; Fe content m Fe 0<m Fe ≤0.3%; the balance is Zn; the single impurity is ≤0.02%, and the total impurities do not exceed ≤0.2%;

[0031] Step 2: smelting;

[0032] Step 3: horizontal continuous casting;

[0033] Step 4: Heating and forging.

[0034] In a preferred embodiment, in the method for manufacturing the forged lead-free copper alloy, in the step three, the temperature of the horizontal continuous casting is 990-1080°C.

[0035] In a preferred embodiment, in the method for manufacturing the forged lead-free copper alloy, the temperature of the heating forging is 680-780°C.

[0036] In a preferred embodiment, in the method for manufacturing the forged lead-free copper alloy, in the step three, the horizontal continuous casting is a horizontal continuous casting rod to obtain a rod material, and after the horizontal continuous casting operation, the obtained rod material is also subjected to a peeling operation and then heated and forged.

[0037] In a preferred embodiment, in the method for manufacturing the forged lead-free copper alloy, in the step three, the horizontal continuous casting is horizontal continuous casting of round ingots to obtain round ingots, and after the horizontal continuous casting operation, the obtained round ingots are also extruded to obtain rods, which are then heated and forged.

[0038] In a preferred embodiment, in the method for producing the forged lead-free copper alloy, the temperature for extruding the obtained ingot is 680-780°C.

[0039] The following examples are provided to further illustrate the forged lead-free copper alloy and the method for manufacturing the same provided by the present invention.

[0040] The compositions of the forged lead-free copper alloys of Examples 1 to 4 of the present invention and the compositions of the alloys used for comparative studies are listed in Table 1. The comparative alloy is the alloy CuZn40Pb2, C36000.

[0041] Table 1 Compositions (wt%) of the alloys prepared in Examples 1 to 4 and the comparative alloys

[0042] alloy Cu Pb Al Fe Sn Zn Alloy 1 57.86 0.05 0.035 0.22 0.21 margin Alloy 2 58.27 0.04 0.028 0.18 0.22 margin Alloy 3 58.13 0.065 0.025 0.19 0.16 margin Alloy 4 57.92 0.045 0.032 0.24 0.19 margin CuZn40Pb2 58.65 1.46 - - - margin C36000 60.24 3.28 - - - margin

[0043] The preparation process of Example 1 and Example 2 is as follows: batching; melting in an industrial frequency induction furnace (i.e., refining with flux); horizontal continuous casting of round ingots; extrusion forming rods to obtain rods; heating and forging. Among them, the temperature of horizontal continuous casting is 990-1080°C, the temperature of extrusion is 680-780°C, and the temperature of heating and forging is 680-780°C. Alloy 1 and Alloy 2 prepared in Example 1 and Example 2, respectively.

[0044] The preparation process of Example 3 and Example 4 is as follows: batching; melting in an industrial frequency induction furnace (i.e., refining with flux); horizontal continuous casting of rods to obtain rods; peeling; heating and forging. The temperature of horizontal continuous casting is 990-1080°C, and the temperature of heating and forging is 680-780°C. Alloy 3 and Alloy 4 are prepared in Example 3 and Example 4, respectively.

[0045] The above alloys will be tested for performance as follows. The specific performance test results are as follows:

[0046] 1. Forging performance

[0047] A sample with a length (height) of 35 mm was cut from a ￠29 mm horizontal continuous casting rod, and hot forged at 680°C and 760°C. The following upsetting rates were used to observe the occurrence of cracks and evaluate the hot forging properties of the alloys in Table 1. The hot forging property test data is shown in Table 2.

[0048] Upsetting rate (%) = [(35-h) / 35] × 100% (h is the height of the sample after hot upsetting)

[0049] If the forging sample surface is smooth and shiny, without obvious cracks, it is excellent, indicated by "●"; if the surface is relatively rough and without obvious cracks, it is good, indicated by "▲"; if there are cracks visible to the naked eye, it is poor, indicated by "×". The results are shown in Table 3.

[0050] Table 2 Hot forging performance test results of alloys prepared in Examples 1 to 4 and comparative alloys

[0051]

[0052]

[0053] It can be seen from the above table that at the same forging temperature, the upsetting rates of alloys 1-4 are slightly higher than those of alloy C36000 and CuZn40Pb2, and their hot forging performance is better.

[0054] 2. Mechanical properties

[0055] The alloy was in the cast state and was machined into ￠10mm specimens from horizontal continuous casting ￠29mm rods. The tensile test was carried out at room temperature. The comparison specimen was leaded brass CuZn40Pb2 of the same state and specification. The results are shown in Table 3.

[0056] Table 3 Physical, mechanical properties and cutting performance of the alloys prepared in Examples 1 to 4 and the comparative alloys

[0057] alloy 1 2 3 4 CuZn40Pb2 Tensile strengthMpa 380 365 410 370 350 Elongation % 15.2 16.1 15.5 15.8 15 Hardness HBW 78 86 82 76 75

[0058] As can be seen from the table above, alloys 1 to 4 have excellent cutting performance, and their tensile strength, elongation and hardness are comparable to those of CuZn40Pb2 alloy. Although the copper content is relatively low, all properties still meet the required requirements.

[0059] In summary, the forged lead-free copper alloy provided by the present invention does not contain toxic elements such as antimony, is an environmentally friendly alloy, has low harm to the human body and the environment, and the amount of dissolution in water meets the NSF / ANSI61-2008 standard. The forged lead-free copper alloy provided by the present invention has excellent mechanical properties. Without annealing to eliminate assembly stress, it still meets the requirements of passing the 4-hour ammonia test or the 24-hour ammonium chloride test (GB / T10567.2) to ensure compliance with the standards. The forged lead-free copper alloy provided by the present invention has excellent performance in use and process performance, and is particularly suitable for forging and turning parts for drinking water supply systems, such as faucet products and various bathroom accessories.

[0060] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A forged lead-free copper alloy, characterized in that: It is composed of the following components in percentage by weight: Cu content m Cu 57.0%≤m Cu ≤59.0%; Pb content m pb 0<m pb ≤0.1%; Al content m Al 0<m Al ≤0.05%; Sn content m Sn 0<m Sn ≤0.3%; Ni content m Ni 0<m Ni ≤0.3%; Fe content m Fe 0<m Fe ≤0.3%; the balance is Zn; individual impurities ≤0.02%, and the total impurities do not exceed ≤0.2%.

2. A method for producing a forged lead-free copper alloy, characterized in that: include: Step 1: Ingredients: The raw materials are composed of the following components in percentage by weight: Cu content m Cu 57.0%≤m Cu ≤59.0%; Pb content m pb 0<m pb ≤0.1%; Al content m Al 0<m Al ≤0.05%; Sn content m Sn 0<m Sn ≤0.3%; Ni content m Ni 0<m Ni ≤0.3%; Fe content m Fe 0<m Fe ≤0.3%; the balance is Zn; the single impurity is ≤0.02%, and the total impurities do not exceed ≤0.2%; Step 2: smelting; Step 3: horizontal continuous casting; Step 4: Heating and forging.

3. The method for producing a forged lead-free copper alloy according to claim 2, wherein: In the step three, the temperature of the horizontal continuous casting is 990-1080°C.

4. The method for producing a forged lead-free copper alloy according to claim 3, wherein: The heating forging temperature is 680-780°C.

5. The method for producing a forged lead-free copper alloy according to claim 2, wherein: In the step three, the horizontal continuous casting is a horizontal continuous casting rod to obtain a rod material. After the horizontal continuous casting operation, the obtained rod material is also subjected to a peeling operation and then heated and forged.

6. The method for producing a forged lead-free copper alloy according to claim 2, wherein: In the step three, the horizontal continuous casting is horizontal continuous casting of round ingots to obtain round ingots. After the horizontal continuous casting operation, the obtained round ingots are also extruded to obtain rods, which are then heated and forged.

7. The method for producing a forged lead-free copper alloy according to any one of claims 4 to 6, wherein: The temperature at which the obtained ingot is extruded is 680 to 780°C.

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