A polished mirror brass bar and a preparation method and application thereof

Abstract

The present application relates to a kind of polished mirror brass rod and its preparation method and application, according to percentage by weight, the raw material composition of brass rod is as follows: Cu 56%-61%, Pb 1.5%-2.2%, Al 0.03%-0.5%, Fe<0.4%, Si<0.5%, Zn and inevitable impurities balance;Si and Fe percentage by weight has the following limit: 0.01≤P Fe / P Si ≤0.2, wherein, P Si It refers to the percentage by weight of Si, P Fe It refers to the percentage by weight of Fe.The preparation method includes batching, smelting, horizontal continuous casting, skinning, wire drawing and other steps.By controlling the proportion of impurity elements Fe and Si, main element Al, while adding lanthanum cerium rare earth, refiner and refining agent, using targeted erosion ultrasonic detection, determine the quality of copper water before furnace, through optimized melting and casting and traction process, can obtain the pipe and bar casting blank with small and uniform structure grain, smooth and delicate surface after polishing;When finished product is applied, can obtain the bathroom piece with no pitting on electroplated surface, and excellent cleanliness.

Description

Technical Field

[0001] This invention relates to the field of metallurgical materials technology, specifically to a polished mirror-finish brass rod, its preparation method, and its application. Background Technology

[0002] Market research on polished mirror-finish brass tubes and rods reveals that with the continuous upgrading of manufacturing industries both domestically and internationally, the demand for high-end materials is constantly increasing. Especially with the rapid development of China's electrification industry in recent years, the demand for copper alloys has also experienced explosive growth. Due to China's deep involvement in international trade, while foreign countries are reforming their industries and increasing the proportion of manufacturing, the proportion of Chinese high-end copper alloy sales in foreign markets is also rapidly rising. In terms of alloy consumption areas, polished mirror-finish copper tubes and rods, with their excellent electrical and thermal conductivity, corrosion resistance, and good luster, have wide applications, especially in home decoration, such as floor drains and bathroom valves.

[0003] Mirror-polished copper tubing, as a high-end processed product of copper tubing, is closely related to the overall demand of the copper tubing market. With the increasing demands for product quality and appearance in the manufacturing industry, the application of mirror-polished copper tubing in electronics, precision instruments, and decoration is gradually increasing, driving the growth of the mirror-polished copper tubing market. Simultaneously, with technological advancements and consumers' pursuit of both aesthetics and performance, the mirror-polished copper tubing market is expected to maintain stable growth in the future. However, the production of this product has a fatal weakness: polishing can produce inclusions, and electroplating can result in pitting. This is mainly due to casting defects and structural defects within the tubing itself.

[0004] Solving the problems of defects and pitting in the polished brass tubes and rods is a task that materials scientists need to undertake. Summary of the Invention

[0005] To address the aforementioned problems, the primary objective of this invention is to provide a polished mirror-finish brass rod that, while ensuring the original comprehensive properties of brass, also possesses excellent mirror-finish polishing performance.

[0006] The second objective of this invention is to provide a method for preparing polished mirror-finish brass rods. The brass rods prepared by this method have high surface smoothness, good mirror effect, no defects or pores after polishing, and no pitting after electroplating.

[0007] The third objective of this invention is to provide an application of polished mirror-finish brass rods, which are particularly suitable for fields such as electronics, instruments, air conditioning components, and household hardware and bathroom fixtures.

[0008] The first aspect of this invention provides a polished mirror-finish brass rod, wherein the raw material composition of the polished mirror-finish brass rod, by weight percentage, is: Cu 56%-61%, Pb 1.5%-2.2%, Al 0.03%-0.5%, Fe < 0.4%, Si < 0.5%, Zn and unavoidable impurities balance; the weight percentage of Si and Fe is limited to: 0.01 ≤ Pb Fe / P Si ≤0.2, where P Si P refers to the percentage by weight of Si. Fe This refers to the weight percentage of Fe.

[0009] In this invention, brass rods with good polishing performance are prepared by controlling the amount of each element added. The weight percentage of Al is 0.03%-0.5%. If the Al content is higher than 0.5%, Al2O3 particles are easily formed, which is detrimental to the stability of polishing performance. If it is lower than 0.03%, it is not conducive to the formation of refined Al2B cores, which is detrimental to grain refinement.

[0010] In this invention, 0.01 ≤ P is simultaneously defined. Fe / P Si If the ratio of the two is too high, it can easily induce the formation of iron particles, resulting in poor polishing. However, if the ratio is too low, it will cause silicon particles (SiO2), resulting in hard polishing particles.

[0011] Preferably, the polished mirror-finish brass rod has a crystal phase containing α phase, β phase and Pb phase.

[0012] And / or, the average grain size of the polished mirror brass rod is 20-35 μm.

[0013] The polished mirror-finish brass rod is free of defects and pores after polishing, and also free of pitting after electroplating.

[0014] The second aspect of this invention provides a method for preparing a polished mirror-finish brass rod, wherein the specific steps of the preparation method are as follows:

[0015] Step S1: Ingredients: Weigh the raw materials according to the proportions and required components;

[0016] Step S2: Smelting: Add the raw materials, refining agent, refining agent and slag remover into the industrial frequency furnace and melt them completely; perform flame treatment, then add phosphor bronze, and after standing, obtain molten copper;

[0017] Step S3: Horizontal continuous casting: Add magnesium blocks to the molten copper, then transfer it to a holding furnace. After the temperature reaches 1050-1080℃, it is drawn to produce copper rods.

[0018] Step S4: Horizontal continuous casting yields a blank. The copper rod is then peeled and drawn to obtain brass rod material.

[0019] Preferably, in step S2, the amount of refining agent added is 0.02-0.04% of the total furnace charge;

[0020] And / or, the amount of the refining agent added is 0.06-0.1% of the total mass of the raw materials; and / or, the amount of the slag remover added is 0.06-0.1% of the total mass of the raw materials.

[0021] Preferably, in step S2, the specific feeding steps are as follows: refiner and copper are added in sequence. After half of the copper is melted, a portion of refining agent and slag remover are added, followed by a portion of zinc ingots. After the copper is completely melted, the remaining zinc ingots and other raw materials are added. After all the copper is melted, the remaining refining agent and slag remover are added. The smelting temperature is 1020-1050℃.

[0022] In this invention, by adding auxiliary materials in batches, thorough slag removal and refining can be ensured. Simultaneously, adding materials in small quantities allows for complete melting of the raw materials, resulting in a more uniform melting process.

[0023] In step S2, the specific steps of flame spraying are as follows: raise the temperature to 1017-1100℃ and maintain it for 10-15 seconds. During flame spraying, a violent oxidation reaction will occur, and the molten copper will be violently agitated.

[0024] Preferably, in step S2, the raw materials of the refining agent, by weight percentage, include: potassium fluorotitanate (K2TiF6) 40-50%, sodium fluoride (NaF2) 5-10%, and industrial boron powder (B) 30-40%.

[0025] And / or, by weight percentage, the raw materials of the refining agent include: dolomite ((Mg,Ca)CO3) 40-60%, sodium carbonate (Na2CO3) 10-20%, sodium aluminate (NaAlO2) 5-10%, cryolite (NaAlF6) 5-10%, and sodium chloride (NaCl) 5-10%.

[0026] The specific reactions that may occur during the raw material smelting process are as follows:

[0027] (Mg,Ca)CO3→MgO+CaO+CO2↑ Equation 1

[0028] Equation 2: Na2CO3→Na2O+CO2↑

[0029] Al2O3 + Na2O → Al2O3,Na2O (Formula 3);

[0030] SiO2 + Na2O → Na2SiO3 (Formula 4)

[0031] B+Al→Al2B (pronuclear point) Equation 5;

[0032] K2TiF6+ Al→Al m Ti n (Original Core Point) Formula Six;

[0033] NaF2 + Al2O3 → AlF3 + Na2O (Formula 7)

[0034] In the smelting reaction process of this invention, potassium fluorotitanate, sodium fluoride, and industrial boron powder react with components such as aluminum in the raw materials to form nucleation sites. Simultaneously, the numerous refining nuclei generated act as nuclei for individual grains, increasing the number of grains and further limiting grain growth, resulting in finer grains. Potassium fluorotitanate primarily acts as a nucleation site by separating titanium elements and combining with aluminum within the melt to form the intermetallic compound aluminum titanate, thus refining the grain structure. Industrial boron powder also combines with metallic aluminum to form boron aluminide, further refining the grain structure of the melt. Sodium chloride accelerates the melt refining reaction by adjusting the melting point, promotes slag formation, accelerates the slag removal and filtration of impurities, and reduces the impurity content in the slag.

[0035] Excessive content of grain refiner components leads to poor melt fluidity, which is detrimental to the surface quality of the cast billet. It also causes a deterioration in the grain refinement effect, while insufficient grain refinement supplementation leads to the formation of coarse dendrites.

[0036] During the smelting process, the oxidation of aluminum and silicon elements inside the melt produces floating slag particles (Al2O3, SiO2). The refining agent mainly acts inside the melt, generating a large number of microbubbles to carry the floating slag particles out of the molten pool to the surface, where they undergo a slagging reaction. However, too many microbubbles can cause significant burn-off, hindering the control of the smelting composition. Too few microbubbles result in insufficient coverage, leaving dead zones with impurities and incomplete processing, which can lead to poor polishing of the product.

[0037] Al2O3 + Na2O → Al2O3,Na2O (Formula 8)

[0038] SiO2 + Na2O → Na2SiO3 (Formula 9)

[0039] In this invention, the usage amount of each component in the refining agent is also limited. Dolomite can provide microbubbles to remove lumps of slag suspended in the melt. However, the decomposition of dolomite produces calcium oxide and magnesium oxide. If too much is used, it will increase the viscosity of the molten copper and the risk of polishing impurities. Therefore, dolomite will not be used entirely, while too little will result in insufficient microbubbles.

[0040] Sodium carbonate can generate microbubbles and decompose sodium oxide for slag formation, but too much will increase the chance of slag agglomerates being suspended, increasing costs, while too little will hinder microbubble generation and slag formation reaction.

[0041] Sodium aluminate can lower the melting point of slag and make it easier to remove ash lumps from the melt. However, excessive use will increase costs and increase the number of suspended slag lumps in the melt. Too low a concentration will result in insufficient refinement, which is not conducive to the removal of slag lumps.

[0042] Cryolite can lower the melting point of slag, making it easier to remove ash lumps from the melt. Too much cryolite increases costs and the risk of fluoride salt inclusions. Too little cryolite can cause the slag to have a high melting point and high slag fluidity and viscosity.

[0043] Sodium chloride is used as a covering to protect against oxidation; if the concentration is too high, the slag viscosity will be too high, and if it is too low, the covering will not be complete.

[0044] Preferably, in step S2, the molten copper is sampled and tested, and horizontal continuous casting is carried out only after the sample passes the test. Preferably, the testing includes polishing quality testing and / or ultrasonic etching testing. The ultrasonic etching testing is performed by preparing a special etching solution and using a corresponding ultrasonic cleaning process. By observing whether there are pits on the surface, the purity of the molten copper before the furnace is determined, thereby determining whether it can proceed to the traction step.

[0045] Preferably, the specific steps for polishing quality inspection are as follows: the equipment used for polishing is a sandbag polishing machine YD-01, and the polishing process is as follows: using 80# cloth wheel - 180# cloth wheel - 320# cloth wheel - 600# cloth wheel - hemp wheel - cloth wheel. After polishing, visual inspection is performed to observe whether there are pores, cracks, hard spots, slag inclusions, etc. on the mirror surface using the principle of reflection.

[0046] And / or, the specific steps of the ultrasonic etching test are as follows: the polished brass sample is placed in the etching solution for 1-3 minutes, then taken out and cleaned in the saponification solution, and finally placed in the ultrasonic cleaning equipment for 5-10 minutes. After taking it out, the morphology of the polished part of the sample is observed under an 8-12W light source to see if there are pits, so as to determine whether the copper molten metal is qualified for refining and impurity removal, so as to meet the conditions for traction.

[0047] Preferably, the etching solution is 30-60g sulfuric acid / L water, and the temperature is 30-60℃; and / or, the ultrasonic frequency of the ultrasonic cleaning equipment is 20KHZ-40 KHZ.

[0048] Preferably, in step S3, the traction process conditions are as follows: traction temperature is 1020-1060℃, traction time is 0.5-2 seconds, traction speed is 6-13 mm / s, pause time is 400-600 ms, reverse push time is 100-150 ms, and intercept is 10-11 mm.

[0049] Preferably, in step S4, the amount of peeling is 0.4-1mm; and / or, the amount of stretching is 0.6-1mm.

[0050] The third aspect of this invention provides the application of the above-mentioned polished mirror brass rod in the fields of electronic appliances, instruments and meters, air conditioning components, and household hardware and sanitary ware.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] This invention controls the ratio of impurity elements Fe and Si to the main element Al during the smelting process, while adding lanthanum, cerium, rare earth elements, refining agents, and refining agents. Targeted etching ultrasonic testing is used to determine the quality of the molten copper before the furnace. Through optimized smelting and casting processes, a fine and uniform microstructure with uniform composition and a smooth, delicate tube-shaped billet after polishing can be obtained. When the finished product is applied to bathroom fixtures, it can produce bathroom fixtures with no pitting on the electroplated surface and excellent cleanliness. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 a is a furnace-polished morphology image of the brass rod from Example 1; Figure 1 b is an electroplating morphology diagram of the sample block in Example 1.

[0055] Figure 2 a is a finished product image of the brass rod from Example 1; Figure 2 b is a cross-sectional view of the brass rod of Example 1.

[0056] Figure 3 a is a furnace-polished morphology diagram of the brass rod material in Example 2; Figure 3 b is an electroplating morphology diagram of the sample block in Example 2.

[0057] Figure 4 a is a finished product image of the brass rod from Example 2; Figure 4 b is a cross-sectional view of the brass rod in Example 2.

[0058] Figure 5 a is a furnace-polished morphology diagram of the brass rod material of Example 3; Figure 5 b is an electroplating morphology diagram of the sample block in Example 3.

[0059] Figure 6This is a finished product image of the brass rod from Example 3.

[0060] Figure 7 a is a furnace-polished morphology of the brass bar in Comparative Example 1; Figure 7 b is the electroplating morphology of the sample from Comparative Example 1.

[0061] Figure 8 a is a SEM image of the surface of the sample in Comparative Example 1 before electroplating. Figure 8 b is a SEM image of the surface of the sample after electroplating in Comparative Example 1.

[0062] Figure 9 This is a finished product image of the brass rod from Comparative Example 1. Detailed Implementation

[0063] Those skilled in the art can refer to the content of this document and appropriately replace and / or modify the process parameters to achieve the desired results. However, it should be particularly noted that all similar replacements and / or modifications are obvious to those skilled in the art and are considered to be included in this invention. The products and preparation methods described in this invention have been described through preferred examples, and those skilled in the art can obviously modify or appropriately change and combine the products and preparation methods described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0064] Unless otherwise defined, the technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention pertains. This invention uses the methods and materials described herein; however, other suitable methods and materials known in the art may also be used. The materials, methods, and examples described herein are illustrative only and are not intended to be limiting. All publications, patent applications, patent cases, provisional applications, database entries, and other references mentioned herein are incorporated herein by reference in their entirety. In case of conflict, the definitions included in this specification shall prevail.

[0065] Unless otherwise stated, all percentages, parts, proportions, etc. are by weight; other statements include, but are not limited to, “wt%” meaning weight percentage, “mol%” meaning mole percentage, and “vol%” meaning volume percentage.

[0066] When quantities, concentrations, or other numerical values ​​or parameters are given as ranges, preferred ranges, or a series of upper and lower preferred values, it should be understood that they specifically disclose all ranges formed by any pair of values ​​of any larger or preferred range limit and any smaller or preferred range limit, regardless of whether the ranges are disclosed separately. For example, when describing a range of “1 to 5 (1-5)”, the described range should be understood to include ranges such as “1 to 4 (1-4)”, “1 to 3 (1-3)”, “1 to 2 (1-2)”, “1 to 2 (1-2) and 4 to 5 (4-5)”, “1 to 3 (1-3) and 5”, etc. Unless otherwise stated, where numerical ranges are described herein, the ranges are intended to include the range endpoints as well as all integers and fractions within that range.

[0067] When the term “about” is used to describe the endpoint of a numerical value or range, the disclosure should be understood to include the specific value or endpoint referred to.

[0068] Furthermore, unless explicitly stated otherwise, "or" refers to an inclusive "or," not an exclusive "or." For example, condition A "or" B applies to any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); and both A and B are true (or exist).

[0069] Furthermore, the indefinite articles “a” and “an” preceding the elements or components of the present invention are intended to indicate that there is no limitation on the number of times the said element or component appears (i.e., occurs). Therefore, “a” or “an” should be understood to include one or at least one, and unless the quantity is explicitly stated to be singular, the singular form of the elements or components also includes the plural case.

[0070] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the phrase "comprising an element defined as..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0071] Unless otherwise specified, the materials, methods, and examples described herein are exemplary and not limiting. While similar or equivalent methods and materials can be used to implement or test the invention, suitable methods and materials are described herein.

[0072] The present invention will now be described in detail.

[0073] According to one embodiment of the present invention, a polished mirror-finish brass rod, by weight percentage, has the following raw material composition: Cu 56%-61%, Pb 1.5%-2.2%, Al 0.03%-0.5%, Fe < 0.4%, Si < 0.5%, Zn and unavoidable impurities balance; the weight percentages of Si and Fe are limited to: 0.01 ≤ Pb Fe / P Si ≤0.2, P Si P refers to the percentage by weight of Si. Fe This refers to the weight percentage of Fe.

[0074] The polished mirror-finish brass rod contains α phase, β phase and Pb phase in its crystal structure, with an average grain size of 20-35 μm.

[0075] According to a preferred embodiment of the present invention, a method for preparing a polished mirror-finish brass rod is provided, the specific steps of which are as follows:

[0076] Step S1: Ingredients: Weigh the raw materials according to the proportions and required components. The raw materials include: copper, zinc ingots, brass shavings (brass Cu 60-61%, Pb 1.2-2.5%, Zn balance), lead, aluminum, silicon, copper-iron alloy, lanthanum, cerium, and rare earth elements.

[0077] Step S2: Smelting

[0078] Step S201: Production is carried out in an industrial frequency furnace. The melting temperature is set to 1020-1050℃. Refining agent (potassium fluorotitanate 40-50wt%, sodium fluoride 5-10wt%, industrial boron powder 30-40wt%) and copper are added in sequence. After half of the copper is melted, some refining agent (dolomite 40-60wt%, sodium carbonate 10-20wt%, sodium aluminate 5-10wt%, cryolite 5-10wt%, sodium chloride 5-10wt%) and slag remover are added. Then some zinc ingots are added. After the copper is completely melted, the remaining zinc ingots and other raw materials are added. After all the copper is melted, the remaining refining agent and slag remover are added.

[0079] The amount of refining agent added is 0.02-0.04% of the total mass of the raw materials.

[0080] The amount of refining agent added is 0.06-0.1% of the total mass of the raw materials.

[0081] The amount of slag remover added is 0.06-0.1% of the total mass of the raw materials.

[0082] Step S202: Then, flame spraying and slag removal are carried out. The specific steps of flame spraying are: raising the temperature to 1070-1100℃ and holding it for 10-15 seconds.

[0083] Step S203: Press in the phosphor bronze with a special spoon, let it stand for 25-30 minutes, then take a sample for polishing and observe the surface texture. Then, put the polished brass sample into the etching solution (30-60g sulfuric acid / L-water, temperature 30-60℃) for 1-3 minutes, then take it out and clean it in the saponification solution. Finally, put it into the ultrasonic cleaning equipment for 5-10 minutes. After taking it out, observe the morphology of the polished part of the sample under an 8-12w light source to see if there are pits, so as to determine whether the copper refining and impurity removal is qualified to meet the conditions for traction.

[0084] Step S3: Horizontal continuous casting: After passing the inspection, magnesium blocks are added to the molten copper, and then the furnace is transferred to a holding furnace. After the temperature reaches 1050-1080℃, the copper rod is drawn to obtain a copper rod. The drawing temperature is 1020-1060℃, the drawing time is 0.5-2s, the drawing speed is 6-13mm / s, the pause time is 400-600ms, the reverse push time is 100-150ms, and the cutoff is 10-11mm.

[0085] Step S4: After converter production, samples are taken and polished, and iron molds are used to obtain sample blocks with a sawing length of 25-600cm; the blanks obtained from continuous casting are then peeled and drawn to obtain brass bars.

[0086] The polished mirror-finish brass rod and its preparation method of the present invention will be described below with reference to the accompanying drawings and embodiments. However, the present invention can be implemented in various different ways and is not limited to the embodiments described herein.

[0087] Example 1

[0088] This embodiment provides a polished mirror-finish brass rod. By weight percentage, the raw material composition of the polished mirror-finish brass rod is: Cu 57.5%, Pb 1.92%, Al 0.42%, Fe 0.075%, Si 0.39%, Zn, and unavoidable impurities. The weight percentages of Si and Fe are limited as follows: P... Fe / P Si =0.2, where P Si P refers to the weight percentage of Si. Fe This refers to the weight percentage of Fe.

[0089] A method for preparing a polished mirror-finish brass rod with a diameter of φ40mm, the specific steps of which are as follows:

[0090] Step S1: Ingredients: Weigh the raw materials according to the proportions and required components. The raw materials include: 850 kg of No. 1 copper (meters), 1050 kg of brass shavings, 684 kg of No. 0 zinc, 4.99 kg of Pb, 10.92 kg of Al, 10.14 kg of Si, 3.9 kg of copper-iron alloy (CuFe50, self-made), and 1 kg of lanthanum-cerium rare earth.

[0091] Step S2: Smelting

[0092] Step S201: Production is carried out in a 3t industrial frequency furnace. The melting temperature is set to 1030℃. 0.78 kg of refining agent (potassium fluorotitanate 50wt%, sodium fluoride 10wt%, industrial boron powder 40wt%) and copper are added in sequence. After half of the copper is melted, 1 kg of refining agent (dolomite 55wt%, sodium carbonate 15wt%, sodium aluminate 10wt%, cryolite 10wt%, sodium chloride 10wt%) and 1 kg of slag remover (purchased from Gan Hong Smelting and Casting Materials Plant, brand name GHJT-1) are added. Then 300 kg of zinc ingots are added. After the copper is completely melted, 384 kg of zinc ingots, 4.99 kg of Pb, 10.92 kg of Al, 3.9 kg of CuFe50, 10.14 kg of Si, and 1 kg of lanthanum and cerium rare earth are added. Then 1050 kg of brass shavings are added. After all the copper is melted, the remaining refining agent and slag remover are added.

[0093] Step S202: Then, the flame is sprayed and the slag is removed. The specific steps of the flame spraying are as follows: by raising the temperature to 1080℃ and holding it for 10 seconds, a violent oxidation reaction is generated and the molten copper is violently stirred.

[0094] Step S203: Press 0.25 kg of phosphorus copper into the sample with a special spoon, let it stand for 25 min, then take a sample for polishing and observe the surface texture. Then, immerse the polished brass sample in an etching solution (50 g sulfuric acid / L-water, temperature 50℃) for 2 min, then take it out and clean it in a saponification solution. Finally, immerse it in an ultrasonic cleaning device for 8 min. After taking it out, observe the morphology of the polished part of the sample under a 10 W light source to see if there are any pits, thereby determining whether the copper refining and impurity removal is qualified to meet the conditions for traction.

[0095] Step S3: Horizontal continuous casting: The ingot specification is φ 40.8 mm; after passing the inspection, 0.05 kg of magnesium block is added to the copper molten metal, and then the furnace is transferred to the holding furnace. After the temperature reaches 1060℃, traction is performed. The traction temperature is 1040℃, the traction time is 1s, the traction speed is 6 mm / s, the pause time is 600ms, the back-pushing time is 150ms, and the cut-off distance is 11mm, resulting in a sample block with a sawing length of 600cm.

[0096] Step S4: Horizontal continuous casting yields a φ40.8 mm blank. The continuously cast blank is peeled and drawn into finished brass bars: φ40.8 mm (peeled) → φ40.2 mm, φ40.2 mm (extended) → φ40 mm.

[0097] The microstructure of the polished mirror-finish brass rod contains α phase, β phase and Pb phase, with an average grain size of 25 μm.

[0098] Depend on Figure 1 and Figure 2 It can be seen that the polished mirror brass rods obtained by the above methods have a high surface smoothness, a very good mirror effect, no defects or pores, and no pitting after electroplating.

[0099] Example 2

[0100] This embodiment provides a polished mirror-finish brass rod. By weight percentage, the raw material composition of the polished mirror-finish brass rod is: Cu 60.5%, Pb 2.15%, Al 0.23%, Fe 0.05%, Si 0.25%, Zn, and unavoidable impurities. The weight percentages of Si and Fe are limited as follows: P... Fe / P Si =0.2, where P Si P refers to the weight percentage of Si. Fe This refers to the weight percentage of Fe.

[0101] A method for preparing a polished mirror-finish brass rod with a diameter of φ25 mm, the specific steps of which are as follows:

[0102] Step S1: Ingredients: Weigh the raw materials according to the proportions and required components. The raw materials include: 850 kg of No. 1 copper (meters), 1205 kg of brass shavings, 533.4 kg of No. 0 zinc, 5.59 kg of Pb, 5.98 kg of Al, 6.5 kg of Si, 2.6 kg of copper-iron alloy (CuFe50), and 1 kg of lanthanum-cerium rare earth.

[0103] Step S2: Smelting

[0104] Step S201: Production is carried out in a 3t industrial frequency furnace. The melting temperature is set to 1050℃. 0.7 kg of refining agent (potassium fluorotitanate 50wt%, sodium fluoride 10wt%, industrial boron powder 40wt%) and copper are added sequentially. After half of the copper is melted, 1 kg of refining agent (dolomite 55wt%, sodium carbonate 15wt%, sodium aluminate 10wt%, cryolite 10wt%, sodium chloride 10wt%) and 1 kg of slag remover (purchased from Gan Hong Smelting and Casting Materials Plant, brand name GHJT-1) are added. Then 300 kg of zinc ingots are added. After the copper is completely melted, 233.4 kg of zinc ingots, 5.59 kg of Pb, 5.98 kg of Al, 2.6 kg of CuFe50, 6.5 kg of Si, and 1 kg of lanthanum and cerium rare earth are added. Then 1205 kg of brass shavings are added. After all the copper is melted, the remaining refining agent and slag remover are added.

[0105] Step S202: Then, the process of ignition and slag removal is carried out. The specific steps of ignition are as follows: by raising the temperature to 1080℃ and holding it for 10-15 seconds, a violent oxidation reaction is generated and the molten copper is violently stirred.

[0106] Step S203: Press 0.25 kg of phosphorus copper into the sample with a special spoon, let it stand for 25 min, then take a sample for polishing and observe the surface texture. Then, immerse the polished brass sample in an etching solution (50 g sulfuric acid / L-water, temperature 50℃) for 2 min, then remove it and clean it in a saponification solution. Finally, immerse it in an ultrasonic cleaning device for 8 min. After removing it, observe the morphology of the polished part of the sample under a 10 W light source to see if there are any pits, thereby determining whether the copper refining and impurity removal is qualified to meet the conditions for traction.

[0107] Step S3: Horizontal continuous casting: The ingot specification is φ 25.6 mm; after passing the inspection, 0.05 kg of magnesium block is added to the copper molten metal, and then the furnace is transferred to the holding furnace. After the temperature reaches 1060℃, traction is performed. The traction temperature is 1060℃, the traction time is 0.6s, the traction speed is 10 mm / s, the pause time is 400ms, the back-pushing time is 100ms, and the cut-off distance is 11mm, resulting in a sample block with a sawing length of 600cm.

[0108] Step S4: Horizontal continuous casting yields a φ25.6 mm blank. The blank is then peeled and drawn to produce finished brass bars: φ25.6 mm (peeled) → φ25.2 mm, φ25.2 mm (extended) → φ25.0 mm.

[0109] The microstructure of the polished mirror-finish brass rod contains α phase, β phase and Pb phase, with an average grain size of 20 μm.

[0110] Depend on Figure 3 and Figure 4It can be seen that the polished mirror brass rods obtained by the above methods have a high surface smoothness, a very good mirror effect, no defects or pores, and no pitting after electroplating.

[0111] Example 3

[0112] This embodiment provides a polished mirror-finish brass rod, produced using 2.6t of molten copper. By weight percentage, the raw material composition of the polished mirror-finish brass rod is: Cu 59.5%, Pb 1.82%, Al 0.26%, Fe 0.012%, Si 0.12%, Zn, and unavoidable impurities. The weight percentages of Si and Fe are limited as follows: P... Fe / P Si =0.1, where P Si P refers to the weight percentage of Si. Fe This refers to the weight percentage of Fe.

[0113] A method for preparing a polished mirror-finish brass rod with dimensions S29×21mm, the specific steps of which are as follows:

[0114] Step S1: Ingredients: Weigh the raw materials according to the proportions and required components. The raw materials include: 850 kg of No. 1 copper (meters), 1161 kg of brass shavings, 577.5 kg of No. 0 zinc, 4.73 kg of Pb, 6.76 kg of Al, 3.12 kg of Si, 2.6 kg of copper-iron alloy (CuFe50), and 1 kg of lanthanum-cerium rare earth.

[0115] Step S2: Smelting

[0116] Step S201: Production is carried out in a 3t industrial frequency furnace. The melting temperature is set to 1030℃. 0.78 kg of refining agent (potassium fluorotitanate 50wt%, sodium fluoride 10wt%, industrial boron powder 40wt%) and copper are added sequentially. After half of the copper is melted, 1 kg of refining agent (dolomite 55wt%, sodium carbonate 15wt%, sodium aluminate 10wt%, cryolite 10wt%, sodium chloride 10wt%) and 1 kg of slag remover (purchased from Gan Hong Smelting and Casting Materials Plant, brand name GHJT-1) are added. Then 300 kg of zinc ingots are added. After the copper is completely melted, 277.5 kg of zinc ingots, 4.73 kg of Pb and 6.76 kg of Al, 2.6 kg of CuFe50, 3.12 kg of Si, and 1 kg of lanthanum and cerium rare earth are added. Then 1161 kg of brass shavings are added. After all the copper is melted, the remaining refining agent and slag remover are added.

[0117] Step S202: Then, the process of ignition and slag removal is carried out. The specific steps of ignition are as follows: by raising the temperature to 1080℃ and holding it for 10-15 seconds, a violent oxidation reaction is generated and the molten copper is violently stirred.

[0118] Step S203: Press 0.25 kg of phosphorus copper into the sample with a special spoon, let it stand for 25 min, then take a sample for polishing and observe the surface texture. Then, immerse the polished brass sample in an etching solution (50 g sulfuric acid / L-water, temperature 50℃) for 2 min, then remove it and clean it in a saponification solution. Finally, immerse it in an ultrasonic cleaning device for 8 min. After removing it, observe the morphology of the polished part of the sample under a 10 W light source to see if there are any pits, thereby determining whether the copper refining and impurity removal is qualified to meet the conditions for traction.

[0119] Step S3: Horizontal continuous casting: The ingot specification is φ 29.6 mm; after passing the inspection, 0.05 kg of magnesium block is added to the copper molten metal, and then the furnace is transferred to the holding furnace. After the temperature reaches 1060℃, traction is performed. The traction temperature is 1040℃, the traction time is 0.5s, the traction speed is 13 mm / s, the pause time is 500 ms, the back-pushing time is 150ms, and the cut-off distance is 10mm, resulting in a sample block with a sawing length of 300cm.

[0120] Step S4: Horizontal continuous casting yields a φ29.6mm blank. The blank is then peeled and drawn to produce finished brass bars: S29.6mm (peeling) → S29.2mm, S29.2mm (extending) → S29.0mm.

[0121] The microstructure of the polished mirror-finish brass rod contains α phase, β phase and Pb phase, with an average grain size of 25 μm.

[0122] Depend on Figure 5 and Figure 6 It can be seen that the polished mirror brass rods produced have a high surface smoothness and a very good mirror effect, with no defects or pores. No pitting was found on the electroplated samples either.

[0123] Comparative Example 1

[0124] This comparative example provides a brass rod produced using 2.6t of molten copper. By weight percentage, the raw material composition is: Cu 60.5%, Pb 1.62%, Al 0.25%, Fe 0.10%, Si 0.15%, Zn, and unavoidable impurities.

[0125] A method for preparing a brass rod with a diameter of φ25 mm, the specific steps of which are as follows:

[0126] Step S1: Ingredients: Weigh the raw materials according to the proportions and required components. The raw materials include: 850 kg of No. 1 copper (meters), 1205 kg of brass shavings, 533.4 kg of No. 0 zinc, 4.212 kg of Pb, 6.5 kg of Al, 3.9 kg of Si, 5.2 kg of copper-iron alloy (CuFe50, self-made), and 1 kg of rare earth.

[0127] Step S2: Smelting

[0128] Step S201: Production is carried out in a 3t industrial frequency furnace. The melting temperature is set to 1040℃. 850kg of copper, 1205kg of brass shavings, 503.388kg of 0# zinc, 4.212kg of Pb, 6.5kg of Al, 3.9kg of Si, 5.2kg of copper-iron alloy (CuFe50, self-made), and 1kg of rare earth are added in sequence. After all the materials are melted, 2kg of refining agent (55wt% dolomite, 15wt% sodium carbonate, 10wt% sodium aluminate, 10wt% cryolite, and 10wt% sodium chloride) and 2kg of slag remover are added.

[0129] Step S202: Then, flame is sprayed. The specific steps of flame spraying are as follows: by raising the temperature to 1080℃ and holding it for 15 seconds, a violent oxidation reaction is generated, and the molten copper is violently stirred.

[0130] Step S3: Horizontal continuous casting: The ingot specification is φ 25.6 mm; 0.05 kg of magnesium block is added to the copper molten metal, and then the furnace is transferred to the holding furnace. After the temperature reaches 1060℃, traction is performed. The traction temperature is 1060℃, the traction time is 0.6s, the traction speed is 10mm / s, the pause time is 400ms, the back-pushing time is 100ms, and the cut-off distance is 11mm, resulting in a sample block with a sawing length of 600cm.

[0131] Step S4: Horizontal continuous casting yields a φ25.6 mm blank. The blank is then peeled and drawn to produce finished brass bars: φ25.6 mm (peeled) → φ25.2 mm, φ25.6 mm (peeled) → φ25 mm, φ25.2 mm (peeled) → φ25.0 mm.

[0132] The microstructure of the polished mirror-finish brass rods contains α phase, β phase and Pb phase, with an average grain size of 35 μm.

[0133] Depend on Figure 7 and Figure 8 It can be seen that the prepared rods have poor surface finish and poor mirror effect after polishing, and contain particles and pores. The electroplated samples show pits and pinholes.

[0134] The detailed composition and electroplating morphology of Examples 1-3 and Comparative Example 1 are shown in Table 1.

[0135] Table 1:

[0136]

[0137] This invention can be implemented in various ways and is not limited to the embodiments and / or examples described above. Those skilled in the art will understand that the invention can be implemented in other specific ways without altering its technical concept or essential features. Therefore, it should be understood that the above embodiments and / or examples are exemplary and not intended to limit the invention.

Claims

1. A polished mirror-finish brass rod, characterized in that, The raw material composition of the polished mirror-finish brass rod, by weight percentage, is: Cu 56%-61%, Pb 1.5%-2.2%, Al 0.03%-0.5%, Fe < 0.4%, Si < 0.5%, with the balance being Zn and unavoidable impurities; the weight percentages of Si and Fe are limited to: 0.01 ≤ P Fe / P Si ≤0.2, where P Si P refers to the weight percentage of Si. Fe This refers to the weight percentage of Fe. The specific steps of the preparation method of the polished mirror brass rod are as follows: Step S1: Ingredients: Weigh the raw materials according to the proportions and required components; Step S2: Smelting: Add the raw materials, refining agent, refining agent and slag remover to the industrial frequency furnace and melt them completely; perform flame treatment, then add phosphor bronze, and after standing, obtain molten copper; Step S3: Horizontal continuous casting: Add magnesium blocks to the molten copper, then transfer it to a holding furnace. After the temperature reaches 1050-1080℃, it is drawn to produce copper rods. Step S4: Horizontal continuous casting yields a blank, which is then peeled and drawn to obtain brass bars; In step S2, the specific feeding steps are as follows: refiner and copper are added in sequence. After half of the copper is melted, a portion of refining agent and slag remover are added, followed by a portion of zinc ingots. After the copper is completely melted, the remaining zinc ingots and other raw materials are added. After all the copper is melted, the remaining refining agent and slag remover are added. The smelting temperature is 1020-1050℃. In step S2, the specific steps of the flame spraying are: raising the temperature to 1070-1100℃ and maintaining it for 10-15 seconds; In step S3, the conditions for the traction process are as follows: traction temperature is 1020-1060 ℃, traction time is 0.5-2s, traction speed is 6-13mm / s, pause time is 400-600ms, reverse push time is 100-150ms, and intercept is 10-11mm. The amount of skin peeled is 0.4-1mm; the amount of fiber extension is 0.6-1mm.

2. The polished mirror-finish brass rod according to claim 1, characterized in that, The polished mirror-finish brass rod has α phase, β phase and Pb phase; the average grain size of the polished mirror-finish brass rod is 20-25 μm.

3. The polished mirror-finish brass rod according to claim 1, characterized in that, In step S2, the amount of refining agent added is 0.02-0.04% of the total furnace charge; the amount of refining agent added is 0.06-0.1% of the total mass of raw materials; and the amount of slag remover added is 0.06-0.1% of the total mass of raw materials.

4. The polished mirror-finish brass rod according to claim 1, characterized in that, In step S2, the raw materials of the refining agent, by weight percentage, include: potassium fluorotitanate 40-50%, sodium fluoride 5-10%, and industrial boron powder 30-40%. By weight percentage, the raw materials for the refining agent include: 40-60% dolomite, 10-20% sodium carbonate, 5-10% sodium aluminate, 5-10% cryolite, and 5-10% sodium chloride.

5. The polished mirror-finish brass rod according to claim 1, characterized in that, In step S2, the molten copper is sampled and tested. If it passes the test, horizontal continuous casting can be carried out. The tests include polishing quality testing and ultrasonic etching testing.

6. The polished mirror-finish brass rod according to claim 5, characterized in that, The specific steps for polishing quality inspection are as follows: The equipment used for polishing is a sandbag polishing machine YD-01. The polishing process is as follows: 80# cloth wheel - 180# cloth wheel - 320# cloth wheel - 600# cloth wheel - hemp wheel - cloth wheel. After polishing, visual inspection is carried out using the principle of reflection to observe whether there are pores, cracks, hard spots, or slag inclusions on the mirror surface. The specific steps of the ultrasonic etching test are as follows: the polished brass sample is placed in the etching solution for 1-3 minutes, then taken out and cleaned in the saponification solution, and finally placed in the ultrasonic cleaning equipment for 5-10 minutes. After taking it out, the morphology of the polished part of the sample is observed under an 8-12W light source to see if there are pits, so as to determine whether the copper molten metal is qualified for refining and impurity removal, so as to meet the conditions for traction. The etching solution is 30-60g sulfuric acid / L water, at a temperature of 30-60℃; the ultrasonic cleaning equipment has an ultrasonic frequency of 20kHz-40kHz.

7. The application of the polished mirror-finish brass rod according to any one of claims 1-2, characterized in that, The polished mirror-finish brass rods are used in the field of household hardware and bathroom products.

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