Polished mirror brass bar as well as preparation method and application thereof

Abstract

The invention relates to a polished mirror brass bar as well as a preparation method and application thereof, and the polished mirror brass bar comprises the following raw materials in percentage by weight: 56-61% of Cu, 1.5-2.2% of Pb, 0.03-0.5% of Al, less than 0.4% of Fe, less than 0.5% of Si and the balance of Zn and inevitable impurities. The weight percentages of Si and Fe are defined as follows: 0.01 < = PFe / PSi < = 0.2, where PSi refers to the weight percentage of Si, and PFe refers to the weight percentage of Fe. The preparation method comprises the steps of burdening, smelting, horizontal continuous casting, scaling, wire drawing and the like. By controlling the proportion of the impurity elements Fe and Si and the main element Al, adding lanthanum cerium rare earth, a refiner and a refining agent at the same time, using targeted erosion ultrasonic detection, judging the quality of molten copper in front of a furnace, and through the optimized casting and traction process, a pipe rod casting blank with fine and uniform structure grains and smooth and fine surface after polishing can be obtained; when a finished product is applied, the bathroom part which has no pocking marks on the electroplated surface and is excellent in cleanliness can be obtained.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgical materials, and in particular to a polished mirror brass rod and a preparation method and application thereof. Background Art

[0002] According to the market research of polished mirror brass tubes and bars, it can be found that with the continuous upgrading of domestic and foreign manufacturing industries, the demand for high-end materials is growing, especially with the rapid development of domestic electrification industry in recent years, the demand for copper alloys has also shown explosive growth. Due to the in-depth cooperation of domestic participation in international trade, foreign countries are reforming their industries and increasing the proportion of manufacturing industries. At the same time, the sales volume of domestic high-end copper alloys in foreign countries is also rising rapidly. From the perspective of alloy consumption, polished mirror copper tubes and bars have a wide range of applications due to their excellent electrical conductivity, thermal conductivity, corrosion resistance and good gloss performance, especially in the field of home decoration, such as floor drains, bathroom valves, etc.

[0003] As a high-end processed product of copper tubes and rods, the market demand for mirror-polished copper tubes and rods is closely related to the overall demand of the copper tube and rod market. With the improvement of the manufacturing industry's requirements for product quality and appearance, the application of mirror-polished copper tubes and rods in electronics, precision instruments, decoration and other fields has gradually increased, which has promoted the growth of the mirror-polished copper tube and rod market. At the same time, with the advancement of technology and consumers' pursuit of both beauty and performance, the mirror-polished copper tube and rod market is expected to maintain steady growth in the future. However, the production of this product has a fatal weakness, that is, there will be particles during polishing, and pitting after electroplating. The main reason is that there are casting defects and organizational defects inside the rod.

[0004] How to solve the above-mentioned problems of particles and pitting of polished brass tubes and bars is a task that materials workers need to carry out. Summary of the invention

[0005] In view of the above problems, the first object of the present invention is to provide a polished mirror brass rod, which has good mirror polishing performance while ensuring the original comprehensive performance of brass.

[0006] The second object of the present invention is to provide a method for preparing a polished mirror brass rod. The brass rod prepared by the method has high surface finish, good mirror effect, no particles and pores after polishing, and no pitting after electroplating.

[0007] The third object of the present invention is to provide an application of a polished mirror brass rod, which is particularly suitable for the fields of electronic appliances, instruments and meters, air-conditioning parts, household hardware and sanitary ware.

[0008] The first aspect of the present invention provides a polished mirror brass rod. The raw material composition of the polished mirror brass rod is: Cu 56%-61%, Pb 1.5%-2.2%, Al 0.03%-0.5%, Fe<0.4%, Si<0.5%, Zn and inevitable impurity remainder; the weight percentage of Si and Fe has the following definition: 0.01≤P Fe / P Si ≤0.2, where P Si Refers to the weight percentage of Si (Percentage by Weight), P Fe Refers to the weight percentage of Fe.

[0009] In the present invention, the preparation of brass rods with good polishing performance is achieved by controlling the addition amount of each element. 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 not conducive to the stability of the polishing performance. If it is lower than 0.03%, it is not conducive to the formation of refined core Al2B, which is not conducive to grain refinement.

[0010] In the present invention, 0.01≤P Fe / P Si ≤0.2. If the ratio of the two is too high, it will 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 the appearance of polishing hard points.

[0011] Preferably, the crystal phase of the polished mirror-finish brass rod contains 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 brass rod has no particles and pores after polishing, and has no pitting phenomenon after electroplating.

[0014] A second aspect of the present invention provides a method for preparing a polished mirror brass rod, the specific steps of the preparation method are: Step S1: Ingredients: weigh the raw materials according to the ratio and required components; Step S2: Smelting: adding raw materials, refiners, refining agents and slag cleaning agents into an industrial frequency furnace and melting them all; performing flame spraying treatment, then adding phosphor copper, and obtaining molten copper after standing; Step S3: Horizontal continuous casting: adding magnesium blocks to molten copper, then transferring the furnace to a holding furnace, and pulling after the temperature reaches 1050-1080°C to obtain a copper rod; Step S4: horizontal continuous casting to obtain a blank, and the copper rod is peeled and drawn to obtain a brass rod.

[0015] Preferably, in step S2, the amount of the refiner added is 0.02-0.04% of the total amount of the charge; 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 cleaning agent added is 0.06-0.1% of the total mass of the raw materials.

[0016] Preferably, in step S2, the specific adding steps are: adding refiner and red copper in sequence, adding part of refining agent and slag removal agent after half of them are melted, and then adding part of zinc ingots, and after the red copper is completely melted, adding the remaining zinc ingots and other raw materials, and adding the remaining refining agent and slag removal agent after all of them are melted; the smelting temperature is 1020-1050°C.

[0017] In the present invention, by adding auxiliary materials in batches, sufficient slag removal and refining can be ensured. At the same time, by adding a small amount of materials, the raw materials can be fully melted, and the smelting process is more uniform.

[0018] In step S2, the specific steps of flame spraying are: raising the temperature to 1017-1100° C. and maintaining it for 10-15 seconds. During the flame spraying, a violent oxidation reaction will occur, and the copper liquid will be violently stirred.

[0019] Preferably, in step S2, the raw materials of the refiner include, by weight percentage: 40-50% potassium fluorotitanate (K2TiF6), 5-10% sodium fluoride (NaF2), and 30-40% industrial boron powder (B).

[0020] 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%.

[0021] The specific reactions that may occur during the raw material smelting process are as follows: (Mg,Ca)CO3→MgO+CaO+CO2↑ Formula 1, Na2CO3→Na2O+CO2↑ Formula 2, Al2O3+ Na2O→Al2O3,Na2O Formula 3; SiO2+ Na2O→Na2SiO3 Formula 4; B+Al→Al2B (pronuclear point) Formula 5; K2TiF6+ Al→Al m Ti n (Pronuclear point) Formula 6; NaF2+Al2O3→AlF3+Na2O Formula 7; During the smelting reaction process of the present invention, potassium fluorotitanate, sodium fluoride, and industrial boron powder react with aluminum and other components in the raw materials to form proto-nuclei, and a large number of refined cores generated at the same time can act on the proto-nuclei of single grains. The increase in the number of grains can further limit the growth of grains, thereby obtaining finer grains. Among them, potassium fluorotitanate mainly separates the titanium element and combines with the aluminum inside the melt to form an intermetallic compound titanium aluminum, which acts as a nucleation point to refine the grain structure. Industrial boron powder also combines with metallic aluminum to form aluminum boron to act on the melt to refine the grain structure. Sodium chloride accelerates the progress of the melt refinement reaction by adjusting the melting point, promotes the slag reaction, accelerates the scum and filtering effect of impurities, and reduces the impurity content in the slag.

[0022] A high content of the refiner component causes poor melt fluidity, which is not conducive to the surface quality of the traction casting. At the same time, it will cause the refinement effect to deteriorate. A low grain refinement supplement will cause the formation of coarse dendrites.

[0023] During the smelting process, the oxidation of aluminum and silicon elements in the melt will produce floating slag points (Al2O3, SiO2). The refining agent mainly acts on the inside of the melt, and produces a large number of microbubbles inside the melt to bring the floating slag points inside the melt out of the molten pool to the surface of the melt, and then slag formation reaction. However, too many microbubbles will cause greater burnout, which is not conducive to the control of smelting components. Too few microbubbles will not cover the area sufficiently, there will be dead zones with impurities, and incomplete treatment will lead to poor polishing of the product.

[0024] Al2O3+ Na2O→Al2O3,Na2O Formula 8; SiO2+ Na2O→Na2SiO3 Formula 9; In the present invention, the usage amount of each component in the refining agent is limited. Among them, dolomite can provide microbubbles to remove the agglomerated slag suspended in the melt, but dolomite decomposes to produce calcium oxide and magnesium oxide. If too much is used, the viscosity of the copper water will increase and the risk of polishing impurity points will increase. Therefore, dolomite will not be used directly, and too little microbubbles will not be enough.

[0025] Sodium carbonate can produce microbubbles and decompose sodium oxide for slag making, but too much will increase the chance of slag agglomerates being suspended, increasing costs, while too little is not conducive to microbubble generation and slag making reactions.

[0026] Sodium aluminate can lower the melting point of slag, making it easier to remove ash lumps from the melt, but using too much will increase costs and increase the amount of suspended slag-like lumps in the melt. Too low alumina will not be sufficiently refined, which is not conducive to the removal of slag lumps.

[0027] Cryolite can lower the melting point of slag, making it easier to remove ash lumps from the melt. Too much will increase costs and the risk of fluoride salt inclusions in the slag, while too little will cause a high melting point of the slag and a high slag fluidity viscosity.

[0028] Sodium chloride is used as a covering to protect against oxidation. If it is too high, the slag viscosity will be high, and if it is too low, the covering will be incomplete.

[0029] Preferably, in step S2, the molten copper is sampled and tested, and horizontal continuous casting is performed only after the sample is qualified. Preferably, the test includes polishing quality test and / or erosion ultrasonic test. The erosion ultrasonic test is to judge the purity of the molten copper in front of the furnace by configuring a special erosion solution and using a corresponding ultrasonic cleaning process, and to judge whether there are pits on the surface, so as to judge whether the traction step can be arranged.

[0030] Preferably, the specific steps of the polishing quality inspection are: the equipment used for polishing is a sandbag polisher YD-01, the polishing process: using 80# cloth wheel - 180# cloth wheel - 320# cloth wheel - 600# cloth wheel - linen wheel - cloth wheel, after polishing is completed, observe with the naked eye, and use the reflection principle to observe whether there are pores, cracks, hard spots, slag inclusions, etc. on the mirror surface.

[0031] And / or, the specific steps of the erosion ultrasonic detection are: placing the polished brass sample into the erosion liquid for 1-3 minutes, then taking it out and washing it in the saponification liquid, and finally putting it into the ultrasonic cleaning equipment for washing for 5-10 minutes. After taking it out, observe the morphology of the polished part of the sample under a 8-12w light source to see if there are pits, so as to determine whether the copper water refining and impurity removal is qualified to meet the traction conditions.

[0032] Preferably, the etching solution is 30-60 g sulfuric acid / L-water, and the temperature is 30-60° C.; and / or the ultrasonic cleaning equipment has an ultrasonic frequency of 20 KHZ-40 KHZ.

[0033] Preferably, in step S3, the conditions of the traction process are: traction temperature is 1020-1060°C, traction time is 0.5-2; traction speed is 6-13 mm / s, dwell time is 400-600 ms, back thrust time is 100-150 ms, and intercept is 10-11 mm.

[0034] Preferably, in step S4, the peeling amount is 0.4-1 mm; and / or the extension amount of the wire drawing is 0.6-1 mm.

[0035] The third aspect of the present invention provides the application of the above-mentioned polished mirror brass rod in the fields of electronic appliances, instruments and meters, air conditioning parts, household hardware and sanitary ware, etc.

[0036] Compared with the prior art, the present invention has the following beneficial effects: In the smelting process, the present invention controls the ratio of impurity elements Fe and Si to the main element Al, adds lanthanum, cerium rare earth, refiner and refining agent at the same time, uses targeted erosion ultrasonic detection to determine the quality of copper water in front of the furnace, and through the optimized melting and traction process, can obtain fine and uniform grains, uniform composition, smooth and delicate surface after polishing of pipe and rod castings, and when the finished product is used for bathroom parts, can obtain bathroom parts with no pitting on the electroplated surface and excellent cleanliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] 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.

[0038] Figure 1 a is a furnace polishing morphology of the brass rod of Example 1; Figure 1 b is the electroplating morphology of the sample block in Example 1.

[0039] Figure 2 a is a finished product image of the brass bar of Example 1; Figure 2 b is a cross-sectional view of the brass rod of Example 1.

[0040] Figure 3 a is a furnace polishing morphology of the brass rod of Example 2; Figure 3 b is the electroplating morphology of the sample block in Example 2.

[0041] Figure 4 a is a finished product image of the brass bar of Example 2; Figure 4 b is a cross-sectional view of the brass rod of Example 2.

[0042] Figure 5 a is a furnace-polished morphology of the brass rod of Example 3; Figure 5 b is the electroplating morphology of the sample block in Example 3.

[0043] Figure 6 This is a finished product picture of the brass rod of Example 3.

[0044] Figure 7 a is the pre-furnace polishing morphology of the brass bar of Comparative Example 1; Figure 7 b is the electroplating morphology of the sample of comparative example 1.

[0045] Figure 8 a is the surface SEM image of the sample of comparative example 1 before electroplating, Figure 8 b is the surface SEM image of the sample in comparative example 1 after electroplating.

[0046] Fig. 9 This is a finished product picture of the brass bar of Comparative Example 1. DETAILED DESCRIPTION

[0047] Those skilled in the art can refer to the content of this article and appropriately replace and / or modify the process parameters to achieve the same. 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 the present invention. The products and preparation methods described in the present invention have been described through preferred examples. It is obvious that relevant personnel can modify or appropriately change and combine the products and preparation methods described herein without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0048] Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. The present 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, patents, provisional applications, database entries, and other references mentioned herein are incorporated herein by reference in their entirety. In the event of a conflict, the present specification, including definitions, shall prevail.

[0049] Unless otherwise specified, all percentages, parts, ratios, etc. are by weight; otherwise specified, including but not limited to, "wt%" means weight percentage, "mol%" means molar percentage, and "vol%" means volume percentage.

[0050] When a quantity, concentration or other numerical value or parameter is given as a range, a preferred range or a series of upper preferred values ​​and lower preferred values, it should be understood that it specifically discloses all ranges formed by any pair of numerical values ​​of any larger range limit or preferred value and any smaller range limit or preferred value, regardless of whether the range is disclosed separately. For example, when describing a range of "1 to 5 (1~5)", the described range should be understood to include a range of "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" and the like. Unless otherwise stated, where a numerical range is described herein, the range is intended to include the range end values ​​and all integers and fractions within the range.

[0051] When the term "about" is used in describing a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to.

[0052] In addition, unless expressly stated to the contrary, "or" refers to an inclusive "or" rather than an exclusive "or". For example, any of the following conditions applies to condition A "or" B: 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).

[0053] In addition, the indefinite articles "a" and "an" before the elements or components of the present invention are intended to indicate that the number of occurrences (i.e., occurrences) of the elements or components is not limited. Therefore, "a" or "an" should be understood to include one or at least one, and unless it is clearly indicated that the number is singular, the elements or components in the singular form also include the plural case.

[0054] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "including an element defined by ... does not exclude the existence of other identical elements in the process, method, article or device including the element".

[0055] Unless specifically stated, the materials, methods, and examples described herein are illustrative only and not limiting. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are still described herein.

[0056] The contents of the present invention are described in detail below.

[0057] According to one embodiment of the present invention, a polished mirror brass rod is provided. The raw material composition of the polished mirror brass rod is, by weight percentage, Cu 56%-61%, Pb 1.5%-2.2%, Al 0.03%-0.5%, Fe<0.4%, Si<0.5%, Zn and unavoidable impurity remainder; the weight percentages of Si and Fe are defined as follows: 0.01≤P Fe / P Si ≤0.2, P Si Refers to the weight percentage of Si (Percentage by Weight), P Fe Refers to the weight percentage of Fe.

[0058] The crystal phase structure of the polished mirror brass rod contains α phase, β phase and Pb phase, and the average grain size is 20-35um.

[0059] According to a preferred embodiment of the present invention, a method for preparing a polished mirror brass rod is provided, and the specific steps of the preparation method are as follows: Step S1: Ingredients: weigh raw materials according to the ratio and required components, the raw materials include: red copper, zinc ingot, brass copper foam (brass Cu 60-61%, Pb 1.2-2.5%, Zn balance), lead, aluminum, silicon, copper-iron alloy, lanthanum, cerium and rare earth.

[0060] Step S2: Smelting Step S201: Production is carried out in an industrial frequency furnace, the smelting temperature is set to 1020-1050°C, and a refiner (potassium fluorotitanate 40-50wt%, sodium fluoride 5-10wt%, industrial boron powder 30-40wt%) and copper are added in sequence. After half of them are melted, part of the refining agent (dolomite 40-60wt%, sodium carbonate 10-20wt%, sodium aluminate 5-10wt%, cryolite 5-10wt%, sodium chloride 5-10wt%) and a slag remover are added, and part of the zinc ingot is added. After the copper is completely melted, the remaining zinc ingot and other raw materials are added. After all of them are melted, the remaining refining agent and slag remover are added; The amount of refiner added is 0.02-0.04% of the total mass of the raw materials. The amount of refining agent added is 0.06-0.1% of the total mass of raw materials. The amount of slag cleaning agent added is 0.06-0.1% of the total mass of the raw materials.

[0061] Step S202: Then, flame spraying and slag removal are performed. The specific steps of flame spraying are: raising the temperature to 1070-1100° C. and maintaining it for 10-15 seconds.

[0062] Step S203: Press phosphor copper with a special spoon, let it stand for 25-30 minutes, then take a sample for polishing and observe the surface particles; then put the polished brass sample into the etching solution (30-60g sulfuric acid / L-water, temperature 30-60℃) for 1-3min, then take it out and wash it in the saponification solution, and finally put it into the ultrasonic cleaning equipment for cleaning for 5-10min. After taking it out, observe the morphology of the polished part of the sample under 8-12w light source to see if there are pits, so as to determine whether the copper water refining and impurity removal is qualified to meet the traction conditions.

[0063] Step S3: Horizontal continuous casting: After passing the inspection, magnesium blocks are added to the copper water, and then the furnace is converted to a holding furnace. After the temperature reaches 1050-1080°C, the copper rod is pulled to obtain a copper rod; wherein, the pulling temperature is 1020-1060°C, the pulling time is 0.5-2s, the pulling speed is 6-13mm / s, the pause time is 400-600ms, the reverse push time is 100-150ms, and the intercept is 10-11mm.

[0064] Step S4: After converter production, samples are taken and polished, and iron mold samples are taken to obtain sample blocks with a sawing length of 25-600 cm; the blanks obtained by continuous casting are peeled and drawn to obtain brass rods.

[0065] The polished mirror brass rod and the preparation method thereof of the present invention are described below in conjunction with the accompanying drawings. However, the present invention can be implemented in various different ways and is not limited to the embodiments described herein.

[0066] Example 1 The present embodiment provides a polished mirror brass rod. The raw material composition of the polished mirror brass rod is, by weight percentage, Cu 57.5%, Pb 1.92%, Al 0.42%, Fe 0.075%, Si 0.39%, Zn and inevitable impurity balance; the weight percentages of Si and Fe are as follows: Fe / P Si =0.2, where P Si Refers to the weight percentage of Si, P Fe Refers to the weight percentage of Fe.

[0067] A method for preparing a polished mirror brass rod with a specification of φ 40 mm, the specific steps are as follows: Step S1: Ingredients: weigh the raw materials according to the ratio and required components, the raw materials include: 850 kg of 1# red copper (rice), 1050 kg of brass copper foam, 684 kg of 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, homemade), and 1 kg of lanthanum, cerium and rare earth.

[0068] Step S2: Smelting Step S201: Production is carried out in a 3t power frequency furnace, the smelting temperature is set to 1030°C, 0.78 kg of refiner (50wt% potassium fluorotitanate, 10wt% sodium fluoride, 40wt% industrial boron powder) and copper are added in sequence, and after half of them are melted, 1 kg of refining agent (55wt% dolomite, 15wt% sodium carbonate, 10wt% sodium aluminate, 10wt% cryolite, 10wt% sodium chloride) and 1 kg of slag remover (purchased from Ganhong Casting Material Factory, brand GHJT-1) are added, and then 300 kg of zinc ingot is added. After the copper is completely melted, 384 kg of zinc ingot, 4.99 kg of Pb and 10.92 kg of Al, 3.9 kg of CuFe50, 10.14 kg of Si, 1 kg of lanthanum cerium rare earth are added, and then 1050 kg of brass copper foam is added. After all of them are melted, the remaining refining agent and slag remover are added.

[0069] Step S202: Then, flame spraying and slag removal are performed. The specific steps of flame spraying are: by raising the temperature to 1080° C. and maintaining it for 10 seconds, a violent oxidation reaction occurs, and the copper liquid is violently stirred.

[0070] Step S203: Use a special spoon to press in 0.25 kg of phosphor copper, let it stand for 25 minutes, then take a sample for polishing and observe the surface particles; then put the polished brass sample into the etching solution (50g sulfuric acid / L-water, temperature 50℃) for 2 minutes, then take it out and wash it in the saponification solution, and finally put it into the ultrasonic cleaning equipment for 8 minutes. After taking it out, observe the morphology of the polished part of the sample under a 10w light source to see if there are pitting, so as to determine whether the copper water refining and impurity removal is qualified to meet the conditions for traction.

[0071] 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 water, and then the furnace is converted to a holding furnace. After the temperature reaches 1060°C, it is pulled. The pulling temperature is 1040°C, the pulling time is 1s, the pulling speed is 6 mm / s, the pause time is 600ms, the back-pushing time is 150ms, the intercept is 11mm, and a sample block with a sawing length of 600cm is obtained.

[0072] Step S4: horizontal continuous casting to obtain a φ 40.8 mm blank, the continuously cast blank is peeled and drawn to obtain a brass rod product, φ40.8 mm (peeling) → φ40.2 mm, φ40.2 mm (extension) → φ40 mm.

[0073] The microstructure of the polished mirror brass rod contains α phase, β phase and Pb phase, and the average grain size is 25 μm.

[0074] Depend on Figure 1 and Figure 2It can be seen that the polished mirror brass rod obtained by the above method has a high surface finish, a very good mirror effect, no particles and pores, and no pitting occurs in the sample after electroplating.

[0075] Example 2 The present embodiment provides a polished mirror brass rod. The raw material composition of the polished mirror brass rod is, by weight percentage, Cu 60.5%, Pb 2.15%, Al 0.23%, Fe 0.05%, Si 0.25%, Zn and inevitable impurity balance; the weight percentages of Si and Fe are defined as follows: Fe / P Si =0.2, where P Si Refers to the weight percentage of Si, P Fe Refers to the weight percentage of Fe.

[0076] A method for preparing a polished mirror brass rod with a specification of φ25 mm, the specific steps are as follows: Step S1: Ingredients: weigh the raw materials according to the ratio and required components, the raw materials include: 850 kg of 1# copper (rice), 1205 kg of brass copper foam, 533.4 kg of 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 and rare earth.

[0077] Step S2: Smelting Step S201: Production is carried out in a 3t power frequency furnace, the smelting temperature is set to 1050°C, 0.7 kg of refining agent (50wt% potassium fluorotitanate, 10wt% sodium fluoride, 40wt% industrial boron powder) and red copper are added in sequence, and after half of them are melted, 1 kg of refining agent (55wt% dolomite, 15wt% sodium carbonate, 10wt% sodium aluminate, 10wt% cryolite, 10wt% sodium chloride) and 1 kg of slag cleaning agent (purchased from Ganhong Melting and Casting Material Factory, brand GHJT-1) are added, and then 300kg of zinc ingot is added. After the red copper is completely melted, 233.4kg of zinc ingot, 5.59kg of Pb, 5.98kg of Al, 2.6kg of CuFe50, 6.5kg of Si, 1kg of lanthanum, cerium and rare earth are added, and then 1205kg of brass copper foam is added. After all of them are melted, the remaining refining agent and slag cleaning agent are added.

[0078] Step S202: Then, flame spraying and slag removal are performed. The specific steps of flame spraying are: by raising the temperature to 1080° C. and maintaining it for 10-15 seconds, a violent oxidation reaction occurs, and the copper liquid is violently stirred.

[0079] Step S203: Use a special spoon to press in 0.25 kg of phosphor copper, let it stand for 25 minutes, then take a sample for polishing and observe the surface particles; then put the polished brass sample into an etching solution (50g sulfuric acid / L-water, temperature 50°C) for 2 minutes, then take it out and wash it in a saponification solution, and finally put it into an ultrasonic cleaning device for 8 minutes. After taking it out, observe the morphology of the polished part of the sample under a 10W light source to see if there are pitting, so as to determine whether the copper water refining and impurity removal is qualified to meet the conditions for traction.

[0080] Step S3: Horizontal continuous casting: the ingot specification is φ 25.6 mm; after the test is qualified, 0.05 kg of magnesium block is added to the copper water, and then the furnace is transferred to the holding furnace, and the temperature reaches 1060°C, and then the pulling is carried out. The pulling temperature is 1060°C, the pulling time is 0.6s, the pulling speed is 10 mm / s, the pause time is 400ms, the back-pushing time is 100ms, the intercept is 11mm, and a sample block with a sawing length of 600cm is obtained; Step S4: Horizontal continuous casting obtains a φ25.6 mm blank, which is peeled and drawn into a brass rod product, φ25.6 mm (peeled) → φ25.2 mm, φ25.2 mm (extended) → φ25.0 mm.

[0081] The microstructure of the polished mirror brass rod contains α phase, β phase and Pb phase, and the average grain size is 20 μm.

[0082] Depend on Figure 3 and Figure 4 It can be seen that the polished mirror brass rod obtained by the above method has a high surface finish, a very good mirror effect, no particles and pores, and no pitting occurs in the sample after electroplating.

[0083] Example 3 The present embodiment provides a polished mirror brass rod, which is produced by using 2.6t of molten copper. The raw material composition of the polished mirror brass rod is as follows: Cu 59.5%, Pb 1.82%, Al 0.26%, Fe 0.012%, Si 0.12%, Zn and inevitable impurity balance by weight percentage; the weight percentages of Si and Fe are as follows: Fe / P Si = 0.1, where P Si Refers to the weight percentage of Si, P Fe Refers to the weight percentage of Fe.

[0084] A method for preparing a polished mirror brass rod with a specification of S29×21mm, the specific steps are as follows: Step S1: Ingredients: weigh raw materials according to the ratio and required components, the raw materials include: 850 kg of 1# red copper (rice), 1161 kg of brass copper foam, 577.5 kg of 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 and rare earth.

[0085] Step S2: Smelting Step S201: Production is carried out in a 3t power frequency furnace, the smelting temperature is set to 1030°C, 0.78 kg of refiner (50wt% potassium fluorotitanate, 10wt% sodium fluoride, 40wt% industrial boron powder) and copper are added in sequence, and after half of them are melted, 1 kg of refining agent (55wt% dolomite, 15wt% sodium carbonate, 10wt% sodium aluminate, 10wt% cryolite, 10wt% sodium chloride) and 1kg of slag remover (purchased from Ganhong Casting Material Factory, brand GHJT-1) are added, and then 300 kg of zinc ingot is added. After the copper is completely melted, 277.5 kg of zinc ingot, 4.73 kg of Pb and 6.76 kg of Al, 2.6 kg of CuFe50, 3.12 kg of Si, 1 kg of lanthanum, cerium and rare earth are added, and then 1161 kg of brass copper foam is added. After all of them are melted, the remaining refining agent and slag remover are added.

[0086] Step S202: Then, flame spraying and slag removal are performed. The specific steps of flame spraying are: by raising the temperature to 1080° C. and maintaining it for 10-15 seconds, a violent oxidation reaction occurs, and the copper liquid is violently stirred.

[0087] Step S203: Use a special spoon to press in 0.25 kg of phosphor copper, let it stand for 25 minutes, then take a sample for polishing and observe the surface particles; then put the polished brass sample into an etching solution (50g sulfuric acid / L-water, temperature 50°C) for 2 minutes, then take it out and wash it in a saponification solution, and finally put it into an ultrasonic cleaning device for 8 minutes. After taking it out, observe the morphology of the polished part of the sample under a 10W light source to see if there are pitting, so as to determine whether the copper water refining and impurity removal is qualified to meet the conditions for traction.

[0088] Step S3: Horizontal continuous casting: the ingot specification is φ 29.6 mm; after the test is qualified, 0.05 kg of magnesium block is added to the copper water, and then the furnace is converted to a holding furnace, and the traction is carried out after the temperature reaches 1060°C. The traction temperature is 1040°C, the traction time is 0.5s, the traction speed is 13 mm / s, the pause time is 500 ms, the back-throwing time is 150ms, the intercept is 10mm, and a sample block with a sawing length of 300cm is obtained; Step S4: Horizontal continuous casting obtains a φ 29.6 mm blank, which is peeled and drawn into a brass rod product, S29.6 mm (peeling) → S29.2 mm, S29.2 mm (extension) → S29.0 mm.

[0089] The microstructure of the polished mirror brass rod contains α phase, β phase and Pb phase, and the average grain size is 25 μm.

[0090] Depend on Figure 5 and Figure 6 It can be seen that the polished mirror brass rod has a high surface finish and a very good mirror effect, without any particles or pores, and no pitting occurs in the sample after electroplating.

[0091] Comparative Example 1 This comparative example provides a brass rod, which is produced by using 2.6t of molten copper as the raw material. The raw material composition is as follows by weight percentage: Cu 60.5%, Pb 1.62%, Al 0.25%, Fe 0.10%, Si 0.15%, Zn and the inevitable impurity balance.

[0092] A method for preparing a brass bar with a specification of φ25 mm, the specific steps are as follows: Step S1: Ingredients: Raw materials are weighed according to the ratio and required components, and the raw materials include: 850 kg of 1# copper (rice), 1205 kg of brass copper foam, 533.4 kg of 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, homemade), and 1 kg of rare earth.

[0093] Step S2: Smelting Step S201: Production is carried out in a 3t industrial frequency furnace, the smelting temperature is set to 1040°C, 850kg of red copper, 1205kg of brass copper foam, 503.388kg of 0# zinc, 4.212kg of Pb, 6.5kg of Al, 3.9kg of Si, 5.2kg of copper-iron alloy (CuFe50, homemade), and 1kg of rare earth are added in sequence, and after all are melted, 2kg of refining agent (55wt% of dolomite, 15wt% of sodium carbonate, 10wt% of sodium aluminate, 10wt% of cryolite, and 10wt% of sodium chloride) and 2kg of slag cleaning agent are added.

[0094] Step S202: flame spraying is then performed. The specific steps of flame spraying are: by raising the temperature to 1080° C. and maintaining it for 15 seconds, a violent oxidation reaction is generated, and the copper liquid is violently stirred.

[0095] Step S3: horizontal continuous casting: the ingot specification is φ 25.6 mm; 0.05 kg of magnesium block is added to the copper water, and then the furnace is converted to a holding furnace, and the traction is carried out after the temperature reaches 1060°C. The traction temperature is 1060°C, the traction time is 0.6s, the traction speed is 10mm / s, the pause time is 400ms, the back-throwing time is 100ms, the intercept is 11mm, and a sample block with a sawing length of 600cm is obtained.

[0096] Step S4: Horizontal continuous casting obtains a φ25.6 mm blank, which is peeled and drawn into a brass rod product, φ25.6 mm (peeled) → φ25.2 mm, φ25.6 mm (peeled) → φ25 mm, φ25.2 mm (peeled) → φ25.0 mm.

[0097] The microstructure of the polished mirror brass rod includes α phase, β phase and Pb phase, and the average grain size is 35 μm.

[0098] Depend on Figure 7 and Figure 8 It can be seen that the polished samples of the prepared rods have poor surface finish, poor mirror effect, the presence of particles and pores, and pits and pitting appear in the samples after electroplating.

[0099] The detailed compositions and electroplating morphologies of Examples 1-3 and Comparative Example 1 are shown in Table 1.

[0100] Table 1:

[0101] 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 polished mirror brass bar, characterized in that: The raw material composition of the polished mirror brass rod is: Cu 56%-61%, Pb 1.5%-2.2%, Al 0.03%-0.5%, Fe<0.4%, Si<0.5%, Zn and inevitable impurity balance; the weight percentage of Si and Fe has the following restrictions: 0.01≤P Fe / P Si ≤0.2, where P Si Refers to the weight percentage of Si, P Fe Refers to the weight percentage of Fe.

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

3. The method for preparing the polished mirror brass rod according to any one of claims 1 to 2, characterized in that: The specific steps of the preparation method are: Step S1: Ingredients: weigh the raw materials according to the ratio and required components; Step S2: Smelting: adding raw materials, refiners, refining agents and slag cleaning agents into an industrial frequency furnace and melting them all; performing flame spraying treatment, then adding phosphor copper, and obtaining molten copper after standing; Step S3: Horizontal continuous casting: adding magnesium blocks to molten copper, then transferring the furnace to a holding furnace, and pulling after the temperature reaches 1050-1080°C to obtain a copper rod; Step S4: horizontal continuous casting to obtain a blank, followed by peeling and wire drawing to obtain a brass rod.

4. The method for preparing the polished mirror brass rod according to claim 3, characterized in that: In step S2, the amount of the refiner added is 0.02-0.04% of the total mass of the charge; and / or, the amount of the refining agent added is 0.06-0.1% of the total mass of the raw material; and / or, the amount of the slag remover added is 0.06-0.1% of the total mass of the raw material.

5. The method for preparing the polished mirror brass rod according to claim 3, characterized in that: In the step S2, the specific steps of adding materials are: adding refiner and copper in sequence, adding part of refining agent and slag removal agent after half of them are melted, and then adding part of zinc ingots, and adding the remaining zinc ingots and other raw materials after the copper is completely melted, and then adding the remaining refining agent and slag removal agent after all of them are melted; the smelting temperature is 1020-1050°C; and / or, in the step S2, the specific steps of flame spraying are: raising the temperature to 1070-1100°C and maintaining it for 10-15s.

6. The method for preparing the polished mirror brass rod according to claim 3, characterized in that: In step S2, the raw materials of the refiner include, by weight percentage: 40-50% potassium fluorotitanate, 5-10% sodium fluoride, and 30-40% industrial boron powder; And / or, by weight percentage, the raw materials of the refining agent include: 40-60% dolomite, 10-20% sodium carbonate, 5-10% sodium aluminate, 5-10% cryolite, and 5-10% sodium chloride.

7. The method for preparing the polished mirror brass rod according to claim 3, characterized in that: In step S2, the molten copper is sampled and tested, and horizontal continuous casting is performed only after the sample is qualified; the test includes polishing quality test and / or erosion ultrasonic test.

8. The method for preparing the polished mirror brass rod according to claim 7, characterized in that: The specific steps of the polishing quality inspection are as follows: the equipment used for polishing is a sandbag polisher YD-01, the polishing process is: using 80# cloth wheel - 180# cloth wheel - 320# cloth wheel - 600# cloth wheel - hemp wheel - cloth wheel, after polishing is completed, observe with the naked eye, and use the reflection principle to observe whether there are pores, cracks, hard spots, slag inclusions, etc. on the mirror surface; And / or, the specific steps of the erosion ultrasonic detection are: placing the polished brass sample into an erosion solution for 1-3 minutes, then taking it out and washing it in a saponification solution, and finally putting it into an ultrasonic cleaning device for washing 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 water refining and impurity removal is qualified to meet the traction conditions; the erosion solution is 30-60g sulfuric acid / L-water, and the temperature is 30-60°C; and / or, the ultrasonic frequency of the ultrasonic cleaning device is 20KHZ-40 KHZ.

9. The method for preparing the polished mirror brass rod according to claim 3, characterized in that: In step S3, the conditions of the pulling process are: pulling temperature is 1020-1060°C, pulling time is 0.5-2s; pulling speed is 6-13mm / s, dwell time is 400-600ms, back thrust time is 100-150ms, and intercept is 10-11mm; And / or, the peeling amount of the peeling is 0.4-1 mm; And / or, the extension amount of the wire drawing is 0.6-1 mm.

10. The use of the polished mirror brass rod according to any one of claims 1-2, characterized in that: The polished mirror brass rod can be applied to the fields of electronic appliances, instruments and meters, air-conditioning parts, and household hardware and sanitary ware.

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