Lead-free corrosion-resistant copper alloy material as well as preparation method and application thereof

Abstract

The invention relates to a lead-free corrosion-resistant copper alloy material as well as a preparation method and application thereof. The copper alloy material comprises the following components in percentage by weight: 61.0-64.0% of Cu; 0.4 to 0.8 percent of Al; 0.04 to 0.09 percent of Fe; less than 0.1% of Pb; ni is less than 0.1%; mn is less than 0.1%; less than 0.01% of Sn; m is more than 0.02% and less than 0.1%, and M is one or more of P, Ca and Mg; the balance is Zn and other inevitable impurities; the phase structure of the copper alloy comprises an alpha phase and a beta phase, the average grain size of the phase structure is smaller than 30 micrometers, the beta phase accounts for 20%-50%, the beta phase is distributed in a non-net mode, and the distance between every two adjacent beta phases is larger than 2 micrometers. The dezincification corrosion resistance value of the obtained brass alloy material is smaller than 150 micrometers, and the machining performance and the cutting performance of the brass alloy material reach 70% HPb63-3.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgical casting, and in particular to a lead-free corrosion-resistant copper alloy material and a preparation method and application thereof. Background Art

[0002] Brass is an alloy product with copper and zinc as the main elements. Due to its good processing and decorative effects, it is widely used in valves, hardware and sanitary ware.

[0003] With the continuous advancement of the demand for lead-free environmental protection, lead-free copper is particularly valued and is expected to gradually replace leaded brass in the future. However, lead-free will cause the processing performance of brass products to deteriorate, and technical research needs to be done in advance. At the same time, because existing brass products are often used in humid and corrosive environments, the workpieces will have certain dezincification corrosion problems, resulting in various safety hazards, so it is also necessary to develop corresponding dezincification corrosion-resistant materials.

[0004] The lead-free brass mentioned in the market at present is mainly improved by simply adding easy-cutting elements such as P, Ca, Si, Sb, etc. to improve the machining performance of the alloy, and by simply adding Sn to improve the dezincification performance. The addition of these alloying elements can improve the cutting performance and dezincification performance of brass to a certain extent, but the degree of improvement is limited, and it cannot replace lead brass in batches under the premise of existing processing equipment.

[0005] In view of the above demand analysis, the current manufacturing of valves and sanitary products needs to be fundamentally improved, that is, to start the design from the organizational performance of the material, to obtain processing performance comparable to lead brass, and products with better corrosion resistance.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] The first object of the present invention is to provide a lead-free corrosion-resistant copper alloy material to address one of the deficiencies of the current technology, so that the brass product is corrosion-resistant and has good processing performance.

[0008] The second object of the present invention is to provide a method for preparing a lead-free corrosion-resistant copper alloy material.

[0009] The third object of the present invention is to provide an application of a lead-free corrosion-resistant copper alloy material.

[0010] The first object of the present invention is achieved through the following technical scheme: a lead-free corrosion-resistant copper alloy material, wherein the copper alloy components include by weight percentage: Cu: 61.0~64.0%; Al: 0.4~0.8%; Fe: 0.04~0.09%; Pb<0.1%; Ni<0.1%; Mn<0.1%; Sn<0.01%; 0.02%<M<0.1%, wherein M is one or more of P, Ca, and Mg; the remainder is Zn and other inevitable impurities; the copper alloy phase structure includes α phase and β phase, the average grain size of the phase structure is less than 30μm, of which the β phase accounts for 20%~50%, and the β phase is non-network distributed, and the distance between adjacent β phases is greater than 2μm.

[0011] Furthermore, the grain size of the α phase is 1-50 μm.

[0012] Through the above technical solution, a brass Cu-Zn system with Al and Fe added is selected to obtain a high-strength matrix. Then, through the control of composition and microstructure, the phase composition is controlled to be mainly α phase and supplemented by β phase, the network distribution of α phase and β phase is removed, the grain size of α phase is reduced and the spacing of β phase is increased. The copper alloy material composed of such composition has a refined structure, extends the corrosion channel path, and improves the material's dezincification corrosion resistance and cutting performance.

[0013] Furthermore, the copper alloy further comprises As: 0.05-0.15%; B: 0.005-0.02% by weight; and / or, the copper alloy phase structure further comprises AsB (0.9~1.1) Complex, the AsB (0.9~1.1) Complex size <5μm, 0.01mm 2 The distribution number is > 5000. Adding a certain proportion of boron and arsenic, by forming As-B compounds to occupy double vacancies, avoids vacancy corrosion migration, and achieves the purpose of preventing dezincification, where the As-B atomic ratio is 0.9~1.1.

[0014] Furthermore, the copper alloy further comprises Si: 0.1-0.3%; Bi: 0.05-0.15% by weight; and / or, the copper alloy phase structure further comprises a CuSi phase dispersed in the grain and at the grain boundary, and a single Bi phase dispersed at the grain boundary, the size of the CuSi phase and the single Bi phase is less than 500 μm, and the size of the CuSi phase is less than 0.01 mm. 2 The distribution number is >5000, the single substance Bi phase is 0.01mm 2 The distribution number is > 10000. Bismuth and silicon are added to improve cutting performance. Silicon is distributed in the form of CuSi phase at the grain boundary and within the grain, and bismuth is distributed in the form of lead-like morphology at the grain boundary to improve cutting performance.

[0015] Furthermore, the dezincification resistance value of the copper alloy is less than 150 μm.

[0016] The second object of the present invention is achieved by the following technical solution: A method for preparing a lead-free corrosion-resistant copper alloy material, comprising the following steps: Step 1: Melting the raw materials: first add the grain refiner into the furnace, weigh each raw material according to the mass ratio for smelting, and after all the raw materials are melted, place them at 990~1020℃ for 5~15min; Step 2: Remove the slag, press in aluminum rare earth after keeping warm, add slag cleaning agent and refining agent at the same time, stir thoroughly, then heat to 1080~1120℃, spray fire for 10~60s and start removing the slag; Step 3: Refining: After the slag is cleaned, cool it down to 990-1020℃ and add refining agent, then heat it up to 1080-1120℃ and keep it for 1-5min; Step 4: Heat treatment: After refining, the copper ingot is taken out of the furnace and needs to be heat treated at 470-530°C for 4-6 hours.

[0017] Through the above technical scheme, by adding grain refiner in front of the furnace for the grain refinement core, strengthening the refinement of the organization, extending the corrosion channel path, improving the material's resistance to dezincification corrosion, and the grain size is less than 30μm. By increasing the cooling intensity and designing the composition to shorten the solidification interval, increase the supercooling, and the supercooling is between 5~30℃, a fine-grained organization is obtained to enhance the dezincification corrosion resistance. Increase heat treatment, control the degree of β-phase decomposition and α-phase precipitation, obtain agglomerate α-phase organization, eliminate the ingot β-phase network structure, obtain a uniformly distributed two-phase organization morphology, and at the same time, the size of the α-phase is between 1 and 50μm, ensuring that there is a certain gap between the β-phases; among them, the β-phase accounts for 20~50%, and the distance between adjacent β-phases is greater than 2μm, which improves the corrosion resistance and cutting performance of the material.

[0018] Furthermore, the raw material smelting in step one is specifically as follows: firstly adding a refiner into a smelting furnace, then adding pure copper to melt, after the pure copper is completely melted, adding brass scraps, elemental silicon, elemental bismuth, elemental arsenic, aluminum-boron alloy, copper-iron alloy, phosphor-copper alloy, copper-calcium alloy and magnesium block in sequence, further melting and then pressing in brass powder, adding zinc ingot and aluminum ingot after melting, and then keeping warm after melting.

[0019] Furthermore, after step three, a step of testing the composition is also included: after refining, the temperature is lowered to 990-1020°C to take samples for testing the composition; after the composition is qualified, the temperature is raised to 1080-1120°C to evaluate the polishing quality of the copper ingot and the fluidity of the molten copper; if the requirements are not met, step three is repeated for refining and batching until the requirements for the molten copper to be discharged from the furnace are met.

[0020] Further, the refiner comprises, by weight percentage, 10-30% cerium dioxide and 70-90% potassium fluoroborate; And / or, the pure copper is a copper raw material with a purity of >99.9%; And / or, the brass powder is a mixture of wire drawing powder and machining powder; And / or, the aluminum rare earth is a lanthanide aluminum rare earth; And / or, the slag cleaning agent comprises, by weight percentage, 20-35% calcium carbonate, 1-10% sodium chloride, 10-30% sodium carbonate, 5-15% silicon dioxide, 5-15% potassium carbonate, and the remainder charcoal powder; And / or, the refining agent comprises, by weight percentage, 40-60% dolomite, 5-15% cryolite, 5-15% sodium chloride, and 20-40% sodium carbonate.

[0021] Furthermore, a cup throwing method was used to evaluate the polishing quality of the copper ingot, and an annular flow channel was used to evaluate the fluidity of the molten copper.

[0022] The third purpose of the present invention is to apply a lead-free, corrosion-resistant copper alloy material to environmentally friendly hardware and sanitary products.

[0023] Compared with the prior art, the present invention has the following beneficial effects: According to the current manufacturing needs of valves and sanitary products, the present invention is fundamentally improved, designed from the aspects of the organizational performance of the material, and the processing performance comparable to that of lead brass and better corrosion resistance are obtained by improving the supercooling strength and designing components to shorten the solidification interval, increase the supercooling degree, and refine the organization. Through heat treatment, the decomposition of the β phase and the precipitation degree of the α phase are controlled to obtain a uniformly distributed two-phase organizational morphology, and ensure that there is a certain gap between the β phases, thereby improving the corrosion resistance and cutting performance of the material. The dezincification corrosion resistance value of the obtained brass alloy material is less than 150μm, and the processing performance\cutting performance reaches 70%HPb63-3. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 a is the metallographic structure diagram of the copper alloy material obtained in Example 1, Figure 1 b is the copper water fluidity test diagram of Example 1;

[0026] Figure 2 The left side is a physical picture of the copper alloy obtained in Example 1. Figure 2The right side is a picture of the copper alloy cutting powder of Example 1;

[0027] Figure 3 a is the metallographic structure diagram of the copper alloy material obtained in Example 2, Figure 3 b is the copper water fluidity test diagram of Example 2;

[0028] Figure 4 The left side is a physical picture of the copper alloy obtained in Example 2. Figure 4 The right side is a picture of the copper alloy cutting powder of Example 2;

[0029] Figure 5 a is the metallographic structure diagram of the copper alloy material obtained in Example 3, Figure 5 b is the copper water fluidity test diagram of Example 3;

[0030] Figure 6 The left side is a physical picture of the copper alloy obtained in Example 3. Figure 6 The right side is a picture of the copper alloy cutting powder of Example 3;

[0031] Figure 7 a is the metallographic structure diagram of the copper alloy material obtained in Comparative Example 1, Figure 7 b is the copper water fluidity test diagram of comparative example 1;

[0032] Figure 8 The left side is a physical picture of the copper alloy obtained in Comparative Example 1. Figure 8 The right side is a picture of the actual copper alloy cutting fragments of comparative example 1. DETAILED DESCRIPTION

[0033] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. Unless the context otherwise clearly indicates the opposite, the singular form used herein is also intended to include the plural form. It should also be understood that the term "comprising" does not specifically refer to a certain characteristic, field, integer, step, action, element and / or component, but excludes the existence or addition of other characteristics, fields, integers, steps, actions, elements, components and / or groups.

[0034] If a part is described as being "on" another part, it may be directly on the other part or there may be other parts therebetween. When a part is described as being "directly on" another part, there may be no other parts therebetween.

[0035] Although not otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art. Terms with definitions in dictionaries should be interpreted as having the same meaning as those disclosed in the relevant technical literature and this article, and should not be interpreted in an idealized or overly formal sense.

[0036] According to one embodiment of the present invention, a lead-free corrosion-resistant copper alloy material is provided, wherein the copper alloy components include by weight percentage: Cu: 61.0~64.0%; Al: 0.4~0.8%; Fe: 0.04~0.09%; Pb<0.1%; Ni<0.1%; Mn<0.1%; Sn<0.01%; P: 0.008~0.01%; Ca: 0.01~0.02%; Mg: 0.01~0.03%; the remainder is Zn and other inevitable impurities; the copper alloy phase structure includes α phase and β phase, the average grain size of the phase structure is less than 30μm, of which the β phase accounts for 20%~50%, and the β phase is non-network distributed, and the distance between adjacent β phases is greater than 2μm.

[0037] According to one embodiment of the present invention, a lead-free corrosion-resistant copper alloy material, the copper alloy components include by weight percentage: Cu: 61.0~64.0%; Al: 0.4~0.8%; Fe: 0.04~0.09%; As: 0.05~0.15%; B: 0.005~0.02%; Pb<0.1%; Ni<0.1%; Mn<0.1%; Sn<0.01%; P: 0.008~0.01%; Ca: 0.01~0.02%; Mg: 0.01~0.03%; the balance is Zn and other inevitable impurities; the copper alloy phase structure includes α phase and β phase, the average grain size of the phase structure is less than 30μm, of which β phase accounts for 20%~50%, and β phase is non-net-shaped distribution, and the distance between adjacent β phases is greater than 2μm. Preferably, the copper alloy phase structure also includes AsB (0.9~1.1) Complex, the AsB (0.9~1.1) Complex size <5μm, 0.01mm 2 Distribution number >5000.

[0038] According to one embodiment of the present invention, a lead-free corrosion-resistant copper alloy material is provided, wherein the copper alloy components include by weight percentage: Cu: 61.0~64.0%; Al: 0.4~0.8%; Fe: 0.04~0.09%; Si: 0.1~0.3%; Bi: 0.05~0.15%; Pb<0.1%; Ni<0.1%; Mn<0.1%; Sn<0.01%; P: 0.008~0.01%; Ca: 0.01~0.02%; Mg: 0.01~0.03%; the remainder is Zn and other inevitable impurities; the copper alloy phase structure includes α phase and β phase, the average grain size of the phase structure is less than 30μm, of which the β phase accounts for 20%~50%, and the β phase is non-network distributed, and the distance between adjacent β phases is greater than 2μm. Preferably, the copper alloy phase structure further includes a CuSi phase dispersed in the grain and at the grain boundary, and a single Bi phase dispersed at the grain boundary, the size of the CuSi phase and the single Bi phase is less than 500 μm, and the size of the CuSi phase is 0.01 mm. 2 The distribution number is >5000, the single substance Bi phase is 0.01mm 2 The number of distributions is >10000.

[0039] According to one embodiment of the present invention, a lead-free corrosion-resistant copper alloy material, the copper alloy components include by weight percentage: Cu: 61.0~64.0%; Al: 0.4~0.8%; Fe: 0.04~0.09%; As: 0.05~0.15%; B: 0.005~0.02%; Si: 0.1~0.3%; Bi: 0.05~0.15%; Pb<0.1%; Ni<0.1%; Mn<0.1%; Sn<0.01%; P: 0.008~0.01%; Ca: 0.01~0.02%; Mg: 0.01~0.03%; the balance is Zn and other inevitable impurities; the copper alloy phase structure includes α phase and β phase, the average grain size of the phase structure is less than 30μm, of which β phase accounts for 20%~50%, and β phase is non-net-shaped distribution, and the distance between adjacent β phases is greater than 2μm. Preferably, the copper alloy phase structure also includes AsB (0.9~1.1) Complex, the AsB (0.9~1.1) Complex size <5μm, 0.01mm 2 The distribution number is >5000; the copper alloy phase structure also includes a CuSi phase dispersed in the grain and at the grain boundary, and a single Bi phase dispersed at the grain boundary, the size of the CuSi phase and the single Bi phase is <500μm, and the CuSi phase is 0.01mm 2 The distribution number is >5000, the single substance Bi phase is 0.01mm 2 The number of distributions is >10000.

[0040] The above-mentioned lead-free corrosion-resistant copper alloy material can be used in environmentally friendly copper processing products, and is particularly suitable for use in environmentally friendly corrosion-resistant environments, and is particularly suitable for use in environmentally friendly hardware and sanitary ware products.

[0041] According to one embodiment of the present invention, a method for preparing the above-mentioned lead-free corrosion-resistant copper alloy material is provided. The method comprises the following steps: Step 1: Add 12 pieces of refiner H (a mixture of cerium dioxide and potassium borofluoride) into a 3t industrial frequency furnace, and then add 1# copper rice or electrolytic plate 1000-1500kg. After the copper rice is completely melted, add 500-800kg of brass scraps, silicon, bismuth, arsenic, aluminum-boron alloy, copper-iron alloy, phosphorus-copper alloy, copper-calcium alloy and magnesium blocks into the furnace. After the scraps are melted, press in brass powder (a mixture of wire drawing powder and machined powder). After the raw materials are melted, add 0# zinc ingot and aluminum ingot. After the raw materials are melted, keep them warm. The insulation temperature is set at 990℃-1020℃.

[0042] Step 2: After the insulation time is 5-15 minutes, use a pressure spoon to press in aluminum rare earth, sprinkle a 2kg bag of slag cleaning agent evenly on the slag surface, press a 2kg bag of refining agent into the copper water, and then stir it thoroughly. Then the furnace temperature is raised to 1080-1120℃, and after spraying fire for 10s-60s, start to remove the slag.

[0043] Step 3: salvage and clean the slag, lower the temperature to 990-1020℃, then press 2kg of refining agent into the copper water with a pressure spoon, raise the temperature to 1080℃-1120℃, keep it warm and refine for 1-5min, then take samples for composition testing.

[0044] Step 4: During the composition test, the temperature is reduced to 990℃-1020℃ for insulation. After the composition is qualified, the temperature is increased to 1080-1120℃. The polishing quality of the copper ingot is evaluated by a cup, and the fluidity of the molten copper is evaluated by an annular flow channel. Finally, samples are taken and polished to evaluate the overall mirror effect of the copper ingot. If any of the items does not meet the requirements, step 3 needs to be repeated for refining and batching until the copper water meets the requirements for discharge from the furnace.

[0045] Step 5: After the copper ingot is taken out of the furnace, it needs to be heat treated at (470-530)℃+ (4-6)h.

[0046] In the above steps, the addition of cerium dioxide trace elements mainly acts as nucleation particles by forming compounds, and affects the growth environment after nucleation, affects the crystallization process, forms new nuclei or changes the environment of grain growth, thereby refining the grains. Rare earth elements can react with impurity elements in the material to form high melting point compounds, which become new nuclei during the crystallization process, or hinder the growth of grains, thereby achieving the effect of refining grains. At the same time, rare earth elements are easily distributed in defects such as grain boundaries and dislocations, increase the resistance of grain boundary movement, thereby hindering the growth of grains. In addition, the compounds formed by rare earth elements are dispersed in the matrix, which can also effectively prevent the merging and growth of grains.

[0047] The lead-free corrosion-resistant copper alloy material and the preparation method thereof of the present invention are described below in conjunction with the embodiments of the accompanying drawings. However, the present invention can be implemented in various different ways and is not limited to the embodiments described herein.

[0048] For the copper alloy materials obtained in Examples 1-3 and Comparative Example 1, a spectrometer was used to test the composition, a homemade flow channel plate was used to test the fluidity, and a dezincification corrosion resistance test was performed according to "Determination of Dezincification Corrosion Resistance of Brass (GB / T 10119-2008)", and the cutting performance was judged by morphology evaluation. The grain size was measured by electron microscopy. The fluidity test standard is shown in Table 1 below.

[0049] Table 1 Fluidity test standards

[0050] Example 1

[0051] Specific production process: The composition of copper ingots requires copper (Cu) 62.3%, aluminum (Al) 0.55%, arsenic (As) 0.08%, boron (B) 0.012%, silicon (Si) 0.2%, bismuth (Bi) 0.09%, iron (Fe) 0.05%, phosphorus (P) 0.008%, calcium (Ca) 0.02%, magnesium (Mg) 0.02%, other single items (lead Pb, nickel Ni, manganese Mn, tin Sn) are all <0.1%, and the balance is zinc (Zn).

[0052] Step 1: Add 12 pieces of refiner H (12g of cerium dioxide, 48g of potassium fluoroborate) into a 3t industrial frequency furnace, and then add 1500kg of 1# copper rice. After the copper rice is completely melted, add 800kg of brass scraps, 5.6kg of combined silicon, 2.5kg of bismuth, 2.2kg of arsenic, 100g of aluminum-boron alloy, 2.8kg of copper-iron alloy, 1.6kg of phosphorus-copper alloy, 11kg of copper-calcium alloy, and 0.6kg of magnesium block into the furnace. After the scraps are melted, 500kg of brass powder (mixed with wire drawing powder and machining powder) is pressed in. After the raw materials are melted, add 0# zinc ingot and aluminum ingot. After the raw materials are melted, keep them warm, and the insulation temperature is set at 1000℃.

[0053] Step 2: After the insulation time is 10 min, 120g of aluminum rare earth (purchased from Ganhong Melting and Casting Technology Materials Co., Ltd., Al rare earth-10%) is pressed in with a pressing spoon, a bag of 2kg slag cleaning agent (calculated by weight percentage, including 30% calcium carbonate, 5% sodium chloride, 20% sodium carbonate, 10% silicon dioxide, 10% potassium carbonate, and the remainder is charcoal powder) is evenly sprinkled on the slag surface, a bag of 2kg refining agent (calculated by weight percentage, including 50% dolomite, 10% cryolite, 10% sodium chloride, and 30% sodium carbonate) is pressed into the copper water, and then fully stirred, and then the furnace temperature is raised to 1110℃, and after 10s of flame spraying, the slag is started.

[0054] Step 3: salvage and clean the slag, lower the temperature to 1000℃, then press 2kg of refining agent (by weight percentage, including 50% dolomite, 10% cryolite, 10% sodium chloride, and 30% sodium carbonate) into the copper water with a pressure spoon, raise the temperature to 1110℃, keep it warm and refine it for 3 minutes, then take samples for composition testing.

[0055] Step 4: During the composition test, the temperature is reduced to 1000℃ for insulation. After the composition is qualified, the temperature is increased to 1120℃. The polishing quality of the copper ingot is evaluated by a cup, and the fluidity of the molten copper is evaluated by a ring flow channel. Finally, samples are taken and polished to evaluate the overall mirror effect of the copper ingot. If any of the items does not meet the requirements, step 3 needs to be repeated for refining and batching until the requirements for the molten copper to be discharged from the furnace are met.

[0056] Step 5: After the copper ingot is taken out of the furnace, it needs to be heat treated at 500℃+6h.

[0057] The spectral composition of the copper ingot is measured as follows: copper (Cu) 62.3%, aluminum (Al) 0.55%, arsenic (As) 0.08%, boron (B) 0.012%, silicon (Si) 0.2%, bismuth (Bi) 0.09%, iron (Fe) 0.05%, phosphorus (P) 0.008%, calcium (Ca) 0.02%, magnesium (Mg) 0.02%, the surface quality of the copper ingot is no residue, the saturation is high, there are no hard spots and pores left after polishing, the fluidity test reaches 3 cycles, showing good casting performance, among which the supercooling is 10℃, the average grain size is 25μm, β phase = 35%, the distance between adjacent β phases is more than 15μm, As-B atomic ratio = 1.02, and the anti-dezincification value is 35 / 65 / 45 / 35 / 45μm. The average grain size of the α phase is 10 μm.

[0058] pass Figure 1 Metallographic analysis in a shows that the obtained alloy material structure is mainly composed of α phase and β phase, Bi, CuSi, As-B complex, the grain structure is fine and uniform, the grain size is 25μm, there is no abnormal mixed crystal, and there is no local organizational abnormality. Figure 1In the flow test analysis in b, the flow channel length is 343mm, the copper liquid flows evenly, the tail end presents a gradient slope, no disconnection and slag solidification are observed, the solidified sample surface is smooth, there is no cracking problem, and the flow performance is excellent. Figure 2 The pattern analysis shows that the obtained copper alloy material has good shrinkage quality, high recognition, and uniform and saturated solidification in the later stage of crystallization.

[0059] Example 2

[0060] Specific production process: Copper ingot composition requirements (mass ratio): copper (Cu) 63.4%, aluminum (Al) 0.65%, arsenic (As) 0.09%, boron (B) 0.015%, silicon (Si) 0.25%, bismuth (Bi) 0.06%, iron (Fe) 0.07%, phosphorus (P) 0.01%, calcium (Ca) 0.02%, magnesium (Mg) 0.03%, other single items (lead Pb, nickel Ni, manganese Mn, tin Sn) are all <0.1%, and zinc (Zn) balance.

[0061] Step 1: Add 12 pieces of refiner H (12g of cerium dioxide, 48g of potassium fluoroborate) into a 3t industrial frequency furnace, and then add 1500kg of 1# copper rice. After the copper rice is completely melted, add 800kg of brass scraps, 7kg of combined silicon, 1.68kg of bismuth, 2.5kg of arsenic, 100g of aluminum-boron alloy, 3.9kg of copper-iron alloy, 2.0kg of phosphorus-copper alloy, 11kg of copper-calcium alloy, and 0.85kg of magnesium block into the furnace. After the scraps are melted, 500kg of brass powder (mixed with wire drawing powder and machining powder) are pressed in. After the raw materials are melted, add 0# zinc ingot and aluminum ingot. After the raw materials are melted, keep them warm, and the insulation temperature is set at 1000℃.

[0062] Step 2: After the insulation time is 10 minutes, use a pressure spoon to press in 500g of aluminum rare earth (purchased from Ganhong Melting and Casting Technology Materials Co., Ltd., Al rare earth-10%), a bag of 2kg slag cleaning agent (by weight percentage, including 30% calcium carbonate, 5% sodium chloride, 20% sodium carbonate, 10% silicon dioxide, 10% potassium carbonate, and the remainder is charcoal powder) Evenly sprinkle on the surface of the slag, a bag of 2kg refining agent (by weight percentage, including 50% dolomite, 10% cryolite, 10% sodium chloride, 30% sodium carbonate) is pressed into the copper water, and then fully stirred, and then the furnace temperature is raised to 1110℃, and after 10s of flame spraying, start to remove the slag.

[0063] Step 3: salvage and clean the slag, lower the temperature to 1000℃, then press 2kg of refining agent (by weight percentage, including 50% dolomite, 10% cryolite, 10% sodium chloride, and 30% sodium carbonate) into the copper water with a pressure spoon, raise the temperature to 1110℃, keep it warm and refine it for 3 minutes, then take samples for composition testing.

[0064] Step 4: During the composition test, the temperature is reduced to 1000℃ for insulation. After the composition is qualified, the temperature is increased to 1120℃. The polishing quality of the copper ingot is evaluated by a cup, and the fluidity of the molten copper is evaluated by a ring flow channel. Finally, samples are taken and polished to evaluate the overall mirror effect of the copper ingot. If any of the items does not meet the requirements, step 3 needs to be repeated for refining and batching until the requirements for the molten copper to be discharged from the furnace are met.

[0065] Step 5: After the copper ingot is taken out of the furnace, it needs to be heat treated at 530℃+6h.

[0066] The spectral composition of the copper ingot is measured as follows: copper (Cu) 63.4%, aluminum (Al) 0.65%, arsenic (As) 0.09%, boron (B) 0.015%, silicon (Si) 0.25%, bismuth (Bi) 0.06%, iron (Fe) 0.07%, phosphorus (P) 0.01%, calcium (Ca) 0.02%, magnesium (Mg) 0.03%, the surface quality of the copper ingot is no residue, the saturation is high, there are no hard spots and pores left after polishing, the fluidity test reaches 3 cycles, showing good casting performance, among which the supercooling is 15℃, the average grain size is 20μm, β phase = 30%, the distance between adjacent β phases is more than 20μm, As-B atomic ratio = 0.95, and the anti-dezincification value is 45 / 55 / 25 / 15 / 45μm. The average grain size of the α phase is 20μm.

[0067] pass Figure 3 a Metallographic analysis shows that the organization is mainly composed of α phase and β phase, Bi, CuSi, As-B complex, the grain organization is fine and uniform, the grain size is 20μm, and there is no abnormal mixed crystal and local organizational abnormality. Figure 3 b Fluidity analysis shows that the flow channel length is 350mm, the flowing copper liquid is relatively uniform, the tail end presents a gradient slope, there is no disconnection and slag solidification, the solidified sample has a smooth surface, no cracking problem, and excellent fluidity performance.

[0068] pass Figure 4 Analysis shows that the copper ingot has good shrinkage quality after annealing, high recognition, and uniform and saturated solidification in the later stage of crystallization. Through machining, the cut foam is crescent-shaped and has good machining performance.

[0069] Example 3

[0070] Specific production process: Copper ingot composition requirements: copper (Cu) 62.5%, aluminum (Al) 0.55%, arsenic (As) 0.1%, boron (B) 0.012%, silicon (Si) 0.15%, bismuth (Bi) 0.12%, iron (Fe) 0.07%, phosphorus (P) 0.01%, calcium (Ca) 0.02%, magnesium (Mg) 0.01%, other single items (lead Pb, nickel Ni, manganese Mn, tin Sn are all <0.1%) and zinc (Zn) remainder.

[0071] Step 1: Add 12 pieces of refiner H (12g cerium dioxide + 48g potassium fluoroborate) into a 3t industrial frequency furnace, and then add 1500kg of 1# copper rice. After the copper rice is completely melted, add 800kg of brass scraps, 4.2kg of combined silicon, 3.36kg of bismuth, 2.8kg of arsenic, 100g of aluminum-boron alloy, 3.9kg of copper-iron alloy, 2.0kg of phosphorus-copper alloy, 11kg of copper-calcium alloy, and 0.28kg of magnesium block into the furnace. After the scraps are melted, 500kg of brass powder (mixed with wire drawing powder and machining powder) is pressed in. After the raw materials are melted, add 0# zinc ingot and aluminum ingot. After the raw materials are melted, keep them warm, and the insulation temperature is set at 1000℃.

[0072] Step 2: After the insulation time is 10 minutes, 500g of aluminum rare earth (purchased from Ganhong Melting and Casting Technology Materials Co., Ltd., Al rare earth-10%) is pressed in with a pressing spoon, a bag of 2kg slag cleaning agent (calculated by weight percentage, including 30% calcium carbonate, 5% sodium chloride, 20% sodium carbonate, 10% silicon dioxide, 10% potassium carbonate, and the remainder is charcoal powder) is evenly sprinkled on the slag surface, a bag of 2kg refining agent (calculated by weight percentage, including 50% dolomite, 10% cryolite, 10% sodium chloride, and 30% sodium carbonate) is pressed into the copper water, and then fully stirred, and then the furnace temperature is raised to 1110℃, and after 10s of flame spraying, the slag is started.

[0073] Step 3: salvage and clean the slag, lower the temperature to 1000℃, then press 2kg of refining agent (by weight percentage, including 50% dolomite, 10% cryolite, 10% sodium chloride, and 30% sodium carbonate) into the copper water with a pressure spoon, raise the temperature to 1110℃, keep it warm and refine it for 3 minutes, then take samples for composition testing.

[0074] Step 4: During the composition test, the temperature is reduced to 1000℃ for insulation. After the composition is qualified, the temperature is increased to 1120℃. The polishing quality of the copper ingot is evaluated by a cup, and the fluidity of the molten copper is evaluated by a ring flow channel. Finally, samples are taken and polished to evaluate the overall mirror effect of the copper ingot. If any of the items does not meet the requirements, step 3 needs to be repeated for refining and batching until the requirements for the molten copper to be discharged from the furnace are met.

[0075] Step 5: After the copper ingot is taken out of the furnace, it needs to be heat treated at 490℃+6h.

[0076] By measuring the spectral composition of the copper material (mass ratio): copper (Cu) 62.5%, aluminum (Al) 0.55%, arsenic (As) 0.1%, boron (B) 0.012%, silicon (Si) 0.15%, bismuth (Bi) 0.12%, iron (Fe) 0.07%, phosphorus (P) 0.01%, calcium (Ca) 0.02%, magnesium (Mg) 0.01%, the surface quality of the copper ingot is free of residue, the saturation is high, there are no hard spots and pores remaining after polishing, the fluidity test reaches 4 cycles, showing good casting performance, with supercooling of 20℃, grain size of 20μm, β phase = 40%, the distance between adjacent β phases is more than 15μm, As-B atomic ratio = 1.01, and anti-dezincification value is 25 / 35 / 15 / 35 / 40μm.

[0077] pass Figure 5 a Metallographic analysis shows that the organization is mainly composed of α phase and β phase, Bi, Si, CuSi, As-B complex, the grain organization is fine and uniform, the average grain size is 20μm, there is no abnormal mixed crystal, and there is no local organizational abnormality. Figure 5 b. Fluidity analysis: the flow channel length is 490 mm, the copper liquid flows evenly, the tail end presents a gradient slope, no disconnection and slag solidification are observed, the solidified sample surface is smooth, no cracking problem, and the fluidity is excellent. The average grain size of the α phase is 30 μm.

[0078] pass Figure 6 Analysis shows that the copper material shrinkage quality after annealing is good, the recognition is high, and the solidification in the later stage of crystallization is uniform and saturated. By machining the copper ingot, the cut foam is crescent-shaped and has good machining performance.

[0079] Comparative Example 1

[0080] Specific production process: Copper ingot composition requirements: copper (Cu) 62.5%, aluminum (Al) 0.55%, arsenic (As) 0.1%, iron (Fe) 0.07%, other single items (lead Pb, nickel Ni, manganese Mn, tin Sn are all <0.1%) and zinc (Zn) balance.

[0081] Step 1: Add 12 conventional refiners (100% potassium borofluoride) into a 3t industrial frequency furnace, then add 1500kg of 1# copper rice. After the copper rice is completely melted, add 800kg of brass scraps, 2.8kg of combined arsenic, and 3.9kg of copper-iron alloy into the furnace. After the scraps are melted, press in 500kg of brass powder (a mixture of wire drawing powder and machined powder). After the raw materials are melted, add 0# zinc ingots and aluminum ingots. After the raw materials are melted, keep them warm at 1000℃.

[0082] Step 2: After the insulation time is 10 minutes, use a pressure spoon to press in 500g of aluminum rare earth, a bag of 2kg slag cleaning agent (calculated by weight percentage, including 30% calcium carbonate, 5% sodium chloride, 20% sodium carbonate, 10% silicon dioxide, 10% potassium carbonate, and the remainder is charcoal powder) is evenly sprinkled on the slag surface, and a bag of 2kg refining agent (calculated by weight percentage, including 50% dolomite, 10% cryolite, 10% sodium chloride, and 30% sodium carbonate) is pressed into the copper water, and then fully stirred, and then the furnace temperature is raised to 1110℃, and after 10s of flame spraying, the slag is started.

[0083] Step 3: salvage and clean the slag, lower the temperature to 1000℃, then press 2kg of refining agent (by weight percentage, including 50% dolomite, 10% cryolite, 10% sodium chloride, and 30% sodium carbonate) into the copper water with a pressure spoon, raise the temperature to 1110℃, keep it warm and refine it for 3 minutes, then take samples for composition testing.

[0084] Step 4: During the composition test, the temperature is reduced to 1000℃ for insulation. After the composition is qualified, the temperature is increased to 1120℃. The polishing quality of the copper ingot is evaluated by a cup, and the fluidity of the molten copper is evaluated by a ring flow channel. Finally, samples are taken and polished to evaluate the overall mirror effect of the copper ingot. If any of the items does not meet the requirements, step 3 needs to be repeated for refining and batching until the requirements for the molten copper to be discharged from the furnace are met.

[0085] By measuring the spectrum of the copper ingot, the material composition was obtained as follows: copper (Cu) 62.5%, aluminum (Al) 0.55%, arsenic (As) 0.1%, iron (Fe) 0.07%, and no residue on the surface quality of the copper ingot. There were hard spots and pores remaining after polishing. The fluidity test reached 2 cycles, showing general casting performance, with supercooling of 2°C, grain size of more than 60μm, β phase = 15%, distance between adjacent β phases of 0, and anti-dezincification value of 325 / 335 / 415 / 335 / 340μm.

[0086] pass Figure 7 a Metallographic analysis shows that the organization is mainly composed of α phase and β phase + Pb phase, the grain organization has developed dendrite organization, the grain size is more than 60μm, there is significant abnormal mixed crystal, and the local organization grains are abnormally proliferated. Figure 7 b. Flow channel analysis: the flow channel length is 208 mm, the flowing molten copper is relatively uniform, the tail end presents a gradient slope, no disconnection and slag solidification are observed, the solidified sample has a smooth surface, no cracking problem, and excellent flow performance.

[0087] pass Figure 8 Analysis shows that the shrinkage quality is average, the recognition is poor, and there is looseness in the late crystallization and solidification stages. After machining the copper ingot, the cut foam is curled and there is wire drawing, which results in poor machining performance.

[0088] The weight percentages (%) of the detailed components of each embodiment and comparative example are shown in Table 2, and the material properties of each embodiment and comparative example are shown in Table 3.

[0089] Table 2

[0090] Table 3

[0091] The present invention can be implemented in various ways and is not limited to the above-mentioned embodiments and / or examples. A person skilled in the art can understand that the present invention can be implemented in other specific ways without changing the technical concept or essential features of the present invention. Therefore, it should be understood that the above-mentioned embodiments and / or examples are exemplary and are not intended to limit the present invention.

Claims

1. A lead-free corrosion-resistant copper alloy material, characterized in that: The copper alloy components include, by weight percentage: Cu: 61.0~64.0%; Al: 0.4~0.8%; Fe: 0.04~0.09%; Pb<0.1%; Ni<0.1%; Mn<0.1%; Sn<0.01%; 0.02%<M<0.1%, wherein M is one or more of P, Ca, and Mg; the remainder is Zn and other inevitable impurities; the copper alloy phase structure includes α phase and β phase, the average grain size of the phase structure is less than 30μm, of which β phase accounts for 20%~50%, and the β phase is non-network distributed, and the distance between adjacent β phases is greater than 2μm.

2. The lead-free corrosion-resistant copper alloy material according to claim 1, characterized in that: The copper alloy further comprises As in weight percentage: 0.05-0.15%; B: 0.005-0.02%; and / or, the copper alloy phase structure further includes AsB (0.9~1.1) Complex, the AsB (0.9~1.1) Complex size <5μm, 0.01mm 2 Distribution number >5000.

3. The lead-free corrosion-resistant copper alloy material according to claim 1, characterized in that: The copper alloy further comprises Si in weight percentage: 0.1-0.3%; Bi: 0.05-0.15%; and / or, the copper alloy phase structure further includes a CuSi phase dispersed in the grain and at the grain boundary, and a single Bi phase dispersed at the grain boundary, the size of the CuSi phase and the single Bi phase is less than 500 μm, and the size of the CuSi phase is 0.01 mm 2 The distribution number is >5000, the single substance Bi phase is 0.01mm 2 The number of distributions is >10000.

4. The lead-free corrosion-resistant copper alloy material according to claim 1, characterized in that: The dezincification resistance value of the copper alloy is <150 μm.

5. A method for preparing a lead-free corrosion-resistant copper alloy material according to any one of claims 1 to 4, characterized in that: The steps include: Step 1: Melting the raw materials: first add the grain refiner into the furnace, weigh each raw material according to the mass ratio for smelting, and after all the raw materials are melted, place them at 990~1020℃ for 5~15min; Step 2: Remove the slag, press in aluminum rare earth after keeping warm, add slag cleaning agent and refining agent at the same time, stir thoroughly, then heat to 1080~1120℃, spray fire for 10~60s and start removing the slag; Step 3: Refining: After the slag is cleaned, cool it down to 990-1020℃ and add refining agent, then heat it up to 1080-1120℃ and keep it for 1-5min; Step 4: Heat treatment: After refining, the copper ingot is taken out of the furnace and needs to be heat treated at 470-530°C for 4-6 hours.

6. The method for preparing a lead-free corrosion-resistant copper alloy material according to claim 5, characterized in that: The raw material smelting in step one is specifically as follows: first add a refiner into the smelting furnace, then add pure copper to melt, after the pure copper is completely melted, add brass scraps, elemental silicon, elemental bismuth, elemental arsenic, aluminum-boron alloy, copper-iron alloy, phosphor-copper alloy, copper-calcium alloy and magnesium block in sequence, press in brass powder after further melting, add zinc ingot and aluminum ingot after melting, and then keep warm after melting.

7. The method for preparing a lead-free corrosion-resistant copper alloy material according to claim 5, characterized in that: After step three, the step of testing the composition is also included: after refining, the temperature is lowered to 990-1020°C to take samples for testing the composition; after the composition is qualified, the temperature is raised to 1080-1120°C to evaluate the polishing quality of the copper ingot and the fluidity of the molten copper; if the requirements are not met, step three is repeated for refining and batching until the requirements for the molten copper to be discharged from the furnace are met.

8. The method for preparing a lead-free corrosion-resistant copper alloy material according to claim 5, 6 or 7, characterized in that: The refiner comprises, by weight percentage, 10-30% cerium dioxide and 70-90% potassium fluoroborate; And / or, the pure copper is a copper raw material with a purity of >99.9%; And / or, the brass powder is a mixture of wire drawing powder and machining powder; And / or, the aluminum rare earth is a lanthanide aluminum rare earth; And / or, the slag cleaning agent comprises, by weight percentage, 20-35% calcium carbonate, 1-10% sodium chloride, 10-30% sodium carbonate, 5-15% silicon dioxide, 5-15% potassium carbonate, and the remainder charcoal powder; And / or, the refining agent comprises, by weight percentage, 40-60% dolomite, 5-15% cryolite, 5-15% sodium chloride, and 20-40% sodium carbonate.

9. The method for preparing a lead-free corrosion-resistant copper alloy material according to claim 5, 6 or 7, characterized in that: The cup throwing method is used to evaluate the polishing quality of copper ingots, and the annular flow channel is used to evaluate the fluidity of molten copper.

10. Application of the lead-free, corrosion-resistant copper alloy material according to any one of claims 1 to 4 in environmentally friendly hardware and sanitary products.

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