Welding high-wettability brass bar as well as preparation method and application thereof

Abstract

The invention discloses a high-wettability brass bar for welding and a preparation method and application of the high-wettability brass bar for welding, and the brass bar comprises the following components in percentage by mass: 57-61% of Cu, 1.0-2.0% of Pb, 0.1-0.4% of Al, 0.1-0.3% of Fe, 10-20 ppm of B, less than 0.5% of Sn, less than 0.1% of Ni and the balance of Zn and inevitable impurities. The welding high-wettability brass bar comprises Fe3Al, FeB and Al2B crystal nucleus particles, and the diameter of the crystal nucleus particles ranges from 1 nm to 5 nm. According to the method, the welding wettability of the brass bar is regulated and controlled by regulating and controlling the composition, size and crystal face distance of crystal nucleus particles in the bar, a proper welding cooling process is developed subsequently, and the air cooling time of the brass welding cooling process is properly prolonged, so that a welding structure is in a nascent state, and the machining performance, the welding performance and the welding performance of the brass bar are improved. The corrosion and electrochemical properties are ensured, and the method has a wide application prospect in the preparation of devices such as electronic and electrical appliances, instruments and meters and the like.

Description

Technical Field

[0001] The invention belongs to the field of metallurgical materials, and in particular relates to a welding high-wettability brass rod and a preparation method and application thereof. Background Art

[0002] With the development of society and the improvement of people's living standards, the demand for the application of copper alloys is increasing. At the same time, people are paying more and more attention to the environmental performance of material applications. Among them, lead brass is widely used in plumbing, sanitary ware, electrical engineering, instrumentation, equipment manufacturing and many other industries due to its excellent mechanical properties, cutting performance, corrosion resistance and forming performance.

[0003] However, in the process of welding brass with copper or stainless steel, the welding is often not tight, which is prone to desoldering, and there are problems such as air leakage and liquid leakage in the sealing test. The existence of this problem poses a great safety hazard to the air conditioning refrigeration pressure seal, electrical performance connection of electrical appliances and equipment structure support. Improving poor welding is an urgent task for material workers.

[0004] Patent document CN113814510B discloses a laser welding process for brass and steel, including: preparing brass workpieces and steel workpieces for welding; galvanizing the surface of the steel; arranging the brass plate and the galvanized steel plate together, using laser melting brazing, concentrating the laser energy mainly on the brass side, melting the brass into liquid, and keeping the steel in solid state, using the molten liquid brass to infiltrate the steel interface to form a brazed joint; this method uses a deep fusion welding mechanism on the brass side and a brazing mechanism on the steel side, uses an oscillating welding method and adjusts a suitable defocusing amount to spread the liquid brass on the steel surface, thereby achieving a smooth, firm and uniform welding of the brass and steel.

[0005] Patent document CN103753021A discloses a laser welding method for copper and brass, comprising the following steps: cleaning the copper and brass to be welded; processing a weld joint at the welding part of the brass to be welded; butting and fixing the brass to be welded and the copper at the weld joint; applying a layer of intermediate material at the weld joint of the brass by laser cladding method; laser welding the copper and brass at the part of the intermediate material; and naturally cooling to complete the preparation. The invention selects Ni-based alloy material as the intermediate material, supplements Si, B and other elements in the Ni-based alloy material, improves the surface quality of the intermediate material, and fills the depression caused by the evaporation of Zn element in the brass during the laser cladding process. At the same time, the laser power density used in the laser cladding process is much lower than the laser power density used for laser welding, which can inhibit the dezincification of brass and ensure the welding quality of brass materials.

[0006] Although the prior art has studied how to improve the welding quality of brass and other metals, there is little research on improving the brass raw material itself to make it have better welding performance. In addition, during the welding process of brass, high-temperature heat flow is used to melt the welding rod, so that the metals to be welded are combined with each other under the adhesion of the solder, but the high temperature will cause the structure of the metal to be welded to change, such as abnormal grain growth, abnormal proliferation of dendrite structure, overburning of the junction and surface dezincification, which seriously affects its welding performance.

[0007] Therefore, it is urgent for material workers to develop a brass rod with excellent welding performance for use in electronic appliances, hardware and sanitary ware industries to solve the welding problem of existing lead brass. Summary of the invention

[0008] The purpose of the present invention is to provide a brass rod with high wettability for welding and a preparation method and application thereof. The brass rod of the present invention has fine and uniform grains, a smooth cutting surface, low roughness, a good mirror effect, and good welding performance when used for subsequent processing.

[0009] The first aspect of the present invention provides a brass rod with high wettability for welding, comprising the following components in percentage by mass: Cu: 57-61%, Pb: 1.0-2.0%, Al: 0.1-0.4%, Fe: 0.1-0.3%, B: 10-20ppm, Sn<0.5%, Ni<0.1%, and the balance is Zn and unavoidable impurities; the brass rod with high wettability for welding comprises Fe3Al, FeB and Al2B crystal nucleus particles, and the diameter of the crystal nucleus particles is 1-5nm.

[0010] The present invention regulates the welding wettability of brass rods by controlling the composition and size of crystal nuclei (crystallization core) particles. Fe3Al, FeB and Al2B as crystal nuclei particles can provide a large number of nucleation sites, thereby refining the structure of brass. This refinement helps to improve the microstructure of brass, making its surface smoother, thereby improving the wettability of brass with other metals or materials.

[0011] Smaller crystal nuclei particles require more energy to overcome the increase in surface energy during growth, so more fine grains can be produced, thereby obtaining a denser material structure. At the same time, the fine-grained polycrystalline boundary structure surface can absorb more molten liquid flow, and by improving strength and toughness, obtain sufficient high-temperature softening resistance, reduce the wetting angle and improve the wetting performance. Therefore, the present invention controls the diameter of the crystal nuclei particles to be less than 5nm. For crystal nuclei particles smaller than 1nm, since more energy is required to overcome the increase in surface energy, only those embryos with a size equal to or greater than a certain critical size can exist stably and grow spontaneously, so the diameter of the crystal nuclei particles is controlled to be above 1nm.

[0012] Preferably, the crystal nucleus particles satisfy the following conditions in the (111) most densely packed plane direction: 0.15nm<crystal plane distance<0.2nm; in the (110) plane direction: 0.2nm<crystal plane distance<0.25nm; in the (100) plane direction: 0.2nm<crystal plane distance<0.25nm; the number of crystal nucleus particles per unit area in the most densely packed direction is 2000-6000 / mm 2 .

[0013] The size of the interplanar spacing will affect the arrangement density and stability of atoms on the crystal plane. The crystal plane with a larger interplanar spacing has a higher surface density, that is, there are more atoms per unit area, which is conducive to the adsorption and arrangement of atoms, thereby promoting the growth of crystals. In order to obtain more refined grains and promote the flow of solder liquid during welding, the smaller the interplanar spacing, the higher the density of the crystal, the greater the hardness and strength of the crystal, and the shape of the material during welding is stabilized to avoid desoldering and cracking problems. At the same time, the present invention combines the requirements of ultrafine grain size below 5um and the requirements of limiting the growth size of crystal nuclei, and finally controls the interplanar distance within the above range.

[0014] Preferably, in the brass bar with high wettability for welding, the mass ratio of Fe, Al and B is 20000-30000:30000-40000:1. The present invention determines the ratio range of relevant elements according to the optimal element ratio of Fe3Al, FeB and Al2B crystal nucleus particles. Excessive iron content will form Fe2O3, an oxide of elemental iron, which affects the bonding degree of welding. Excessive aluminum content will form aluminum oxide Al2O3, which will affect the density of welding, causing desoldering and excessive welding slag. Excessive boron content will cause boron oxide B2O3, causing the risk of cracking during welding and the bonding degree of welding. Too low an element will cause abnormalities in other related elements, and ultimately cause welding abnormalities. More preferably, in the brass bar with high wettability for welding, the mass ratio of Fe, Al and B is 25000-30000:34000-40000:1.

[0015] Preferably, the roughness of the brass rod with high wettability for welding is ≤0.05um. The present invention controls the roughness of the brass rod to ≤0.05um, which can obtain a good mirror effect, making the rod surface very smooth, and the welding process can be well vented and deslaged, thereby achieving the effect of improving wettability.

[0016] Preferably, the wetting angle of the brass rod with high wettability during welding is 5-7°. If the wetting angle is lower than 5°, the solder will be too thin and too extended, resulting in shrinkage and cracking of the welding layer. If the wetting angle is higher than 7°, the welding will easily cause the problem of stacking, slag inclusion, unstable welding wetting, and air leakage.

[0017] The second aspect of the present invention provides a method for preparing the brass rod with high wettability for welding, comprising the following steps: batching → melting and casting → wire drawing → annealing → grinding;

[0018] Wherein, in the melting and casting process, the refiner used is a mixture of potassium fluoroborate, potassium fluorotitanate and potassium fluorosilicate;

[0019] In the melting and casting process, secondary water ring cooling is adopted, the temperature of the rod out of the crystallizer is 550-650°C, and the temperature of the rod after secondary water ring cooling is 15-30°C.

[0020] Based on the refiner, the present invention obtains the crystal nucleus particles of the above-mentioned size and crystal plane distance by controlling the melting and casting process. The present invention obtains a certain degree of supercooling by combining the crystal nucleus particles synthesized by the B element in the refiner during the melting and casting process with the melting and casting temperature and the cooling rate, controls the grain production, and obtains the required grain size and crystal plane distance.

[0021] The refiner is mainly used to refine the grain structure of brass. The refiner of the present invention enters the copper water to form Fe3Al, FeB and Al2B crystal nuclei of smaller size, which can produce more fine grains, thereby obtaining a denser material structure, absorbing more molten liquid flow, improving the strength, toughness and high temperature softening resistance of the prepared material, reducing the wetting angle and improving the wetting performance. In addition, the refiner crystal nuclei of the present invention play a role in inhibiting grain growth during the welding process.

[0022] Existing refiners such as boron aluminum alloy, ferroboron, potassium fluoroborate and boron powder have blind spots in the refinement process, and are prone to refiner poisoning and poor quality of refined crystal nucleus particles. The refiner of the present invention uses a mixture of potassium fluoroborate, potassium fluorotitanate and potassium fluorosilicate. The addition of fluorine salt can reduce the triggering problem of the core reaction of the crystal nucleus particles, making the grains finer and more uniform, which can overcome the above problems.

[0023] In addition, the refiner of the present invention can evenly distribute the lead particles and improve the comprehensive mechanical properties of the material. As the grains are refined and the interface channels are increased, the second phase cutting particles Pb phase can be more evenly distributed in the matrix and grain boundaries, making the processed products smoother, the chips finer, and the processed surface roughness lower.

[0024] Preferably, in the refiner, the mass ratio of potassium fluoroborate, potassium fluorotitanate and potassium fluorosilicate is 6 to 8: 1 to 2: 2 to 4. The refiner of this composition has a good refinement effect and can better improve the comprehensive properties of the material such as wettability, strength and toughness.

[0025] Preferably, the amount of the refiner added is 0.02-0.05% of the total mass of the raw material. The present invention controls the formation of Fe3Al, FeB and Al2B nuclei in the alloy rod by controlling the composition and amount of the refiner to provide a large number of nucleation sites, thereby refining the structure of brass and avoiding the appearance of Fe2O3, Al2O3 or B2O3 oxides, which affect the welding performance of the material.

[0026] More preferably, the amount of the refiner added is 0.03% of the total mass of the raw material.

[0027] Preferably, the secondary water ring cooling is carried out in a water ring cooling device, which includes a first water ring and a second water ring with a spacing of 50 to 200 mm. The first water ring and the second water ring are provided with water inlets, and the inner wall of the water ring is provided with a plurality of water spray holes with the water spray direction inclined downward. During the cooling process, cooling water is sprayed out from the water spray holes to cool the rods passing through the center of the first water ring and the second water ring in sequence.

[0028] Preferably, the water spray holes are arranged in a circle along the inner wall of the water ring.

[0029] Preferably, in the secondary water ring cooling process, the primary cooling water flow rate is 10-40m 3 / h, the secondary cooling water flow rate is 1~30m 3 / h, water pressure is 0.4~0.6MPa, water inlet temperature is 20~40℃, and water outlet temperature is 40~60℃.

[0030] Preferably, in the melting and casting process, raw materials are added according to the alloy composition ratio, and insulation is carried out after melting. The insulation temperature is 980-1020°C and the insulation time is 3-5min. After the insulation is completed, the furnace temperature is increased to 1050-1080°C. After refining and slag removal, the temperature is lowered to 1000-1030°C, the above-mentioned refiner is added, stirred, and after the spectral test component is qualified, traction casting is carried out. The traction speed is 220-400mm / min and the traction temperature is 1030-1040°C.

[0031] Preferably, in the stress relief annealing process, the annealing temperature is 280-350° C. and the annealing time is 2-4 hours. In the stress relief annealing of the present invention, uniform annealing is adopted to eliminate tissue defects.

[0032] Preferably, in the grinding process, the roughness of the rod is controlled below 0.05um. After the rod is annealed, the surface roughness is relatively high, which will become a refuge for pores and slag inclusions during the welding process. Therefore, it is necessary to obtain mirror-grade rods. By grinding and polishing the surface of the rod, the surface of the rod can be made very smooth, and the welding process can be well vented and deslaged, achieving the effect of improving the wetting performance. The roughness of the rod ≤ 0.05um can obtain a better mirror effect.

[0033] The third aspect of the present invention provides the use of the brass rod with high wettability for welding in the preparation of electronic appliances, instruments and meters, or hardware and sanitary ware accessories. The brass rod of the present invention has good welding performance while ensuring the original comprehensive performance of lead brass, and has broad application prospects in electronic appliances, instruments and meters, or hardware and sanitary ware.

[0034] Preferably, in the process of preparing the above-mentioned electronic appliances, instruments and meters or hardware and sanitary ware accessories, the brass rod is welded with other metal materials, and after welding, the obtained welding material is air-cooled for 10 to 25 seconds and then water-cooled.

[0035] During the brass welding process, high-temperature heat flow is used to melt the welding rod, so that the metals to be welded are combined with each other under the adhesion of the solder. However, high temperature will also cause changes in the metal structure being welded, such as abnormal grain growth, abnormal proliferation of dendrite structure, overburning of the junction, and surface dezincification. By developing a suitable welding cooling process, the welding structure can be kept in its original state, and the processing performance, welding performance, corrosion and electrochemical properties can be guaranteed.

[0036] The time of the welding cooling process will cause changes in the structure. In the prior art, a shorter welding air cooling time (about 5s) is usually used, which makes the structure of the welding material at high temperature mainly a coarse β-phase grain structure. At this time, rapid cooling will cause the coarse, hard and brittle β-phase to remain in the room temperature structure. At the same time, the stress of the material is also increased, which eventually causes the risk of cracking of the material.

[0037] The invention prolongs the air cooling time in the welding cooling process to 10 to 25 seconds, and then performs rapid cooling, so as to obtain a better fine-grained structure, avoid the deterioration of brass structure performance during the welding process, and improve the stability of welding.

[0038] Compared with the prior art, the present invention has at least the following beneficial effects:

[0039] (1) The present invention controls the melting and casting process by adding a special refiner to the melting and casting process, and obtains a certain degree of supercooling by combining the crystal nucleus particles formed by the B element in the refiner with the melting and casting temperature and the cooling rate, thereby controlling the grain production and obtaining the required grain size and crystal plane distance. The present invention can adjust the composition, size and crystal plane distance of the crystal nucleus particles, thereby adjusting the welding wettability of the brass rod, and improving the strength, toughness and high temperature softening resistance of the brass rod.

[0040] (2) After the rod is annealed, the surface of the rod is ground and polished to obtain a rod with a good mirror effect, so that the rod can be well vented and deslaged during the welding process, thereby achieving the effect of improving the wetting performance.

[0041] (3) The present invention develops a suitable welding cooling process during brass welding, and appropriately prolongs the air cooling time of the brass welding cooling process so that the welding structure is in its initial state, thereby ensuring its processing performance, welding performance, corrosion and electrochemical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Schematic diagram of a secondary water ring cooling device in an embodiment of the present invention; 1-first water ring; 2-second water ring.

[0043] Figure 2 This is a microscopic metallographic image of the brass rod prepared in Example 1.

[0044] Figure 3 The wetting angle of the brass rod prepared for Example 1 during welding.

[0045] Figure 4 This is a microscopic metallographic image of the brass rod prepared in Example 2.

[0046] Figure 5 The wetting angle of the brass rod prepared for Example 2 during welding.

[0047] Figure 6 This is a microscopic metallographic image of the brass rod prepared in Example 3.

[0048] Figure 7 The wetting angle of the brass rod during welding was prepared for Example 3.

[0049] Figure 8 This is the microscopic metallographic image of the brass rod prepared in Comparative Example 1.

[0050] Fig. 9 The wetting angle of the brass rod during welding was prepared for Comparative Example 1. DETAILED DESCRIPTION

[0051] Example 1

[0052] The alloy composition of this embodiment is: Cu59.50%, Pb1.50%, Al0.35%, Fe0.25%, Sn0.2%, Ni0.04%, the balance is Zn, and the content of B is 11ppm. A special refiner X for brass (potassium fluoroborate 70%, potassium fluorosilicate 20%, potassium fluorotitanate 10%) is configured, and the addition amount of the refiner X is 0.03% of the total amount of the charge.

[0053] Produced in 3t power frequency furnace Casting billet peeling production Rod.

[0054] Casting process:

[0055] 1. Add 2.5t of processed recycled materials into the industrial frequency furnace in two batches. First, add 1.5t of recycled materials into the furnace. After the recycled materials are completely melted, add the remaining 1t of processed recycled materials into the furnace. After the recycled materials are completely melted, keep them warm at 980℃-1020℃.

[0056] 2. After the insulation is completed, the furnace temperature is increased to 1050℃-1080℃, and the flame is sprayed for about 1 minute. The refining agent is added into the furnace and then stirred. After stirring, the slag in the furnace can be cleaned up, and the temperature is lowered to 1000℃-1030℃. Samples are taken for spectrum testing. At the same time, 800g of refiner X is pressed into the furnace with a pressing spoon, stirred for 1 minute, and then kept warm and still. If the spectrum test is qualified, traction casting can be arranged.

[0057] 3. If the spectrum test component is qualified, arrange the traction, the traction speed is 320mm / min, the traction temperature is 1030-1040℃, the ingot specifications In the casting process of this embodiment, secondary water ring cooling is adopted, and the primary cooling water flow rate is 25m 3 / h, the secondary cooling water flow rate is 25m 3 / h, water pressure is 0.4-0.6MPa, water inlet temperature is 20-40℃, water outlet temperature is 40-60℃, the temperature of continuous casting bars out of crystallizer is 550-650℃, and the temperature of casting bars after secondary cooling is 15-30℃.

[0058] The schematic diagram of the secondary water ring cooling device in the embodiment of the present invention is as follows Figure 1 As shown. The secondary water ring cooling device includes a first water ring and a second water ring, and the distance between the first water ring and the second water ring is 150mm. The inner walls of the first water ring and the second water ring are provided with a plurality of water spray holes with the water spray direction inclined downward, and the water spray holes are arranged circumferentially along the inner walls of the water rings. During the cooling process, primary water enters the water chamber from the water inlet 1, and water is discharged through the water spray holes on the water outlet 1 to cool the continuous casting rods for the first time. Secondary water enters the water chamber from the water inlet 2, and water is discharged through the water spray holes on the water outlet 2 to cool the continuous casting rods for the second time.

[0059] Wire drawing process:

[0060] The rough material is directly pulled onto the straight pull car for peeling to produce semi-finished products.

[0061] Stress relief annealing:

[0062] The rod is subjected to stress relief heating annealing at a temperature of 300°C for 3 hours.

[0063] Grinding process:

[0064] The ground rods after annealing are continuously polished with a polishing wheel, and the roughness of the polished rods is less than 0.05um.

[0065] Careful inspection and storage.

[0066] Customer welding: In the actual welding process, the cooling temperature needs to be based on the actual efficiency requirements, and the air cooling time is extended to 15s for water cooling.

[0067] The alloy composition and microstructure parameters of the product of this embodiment are shown in Table 1 and Table 2 respectively.

[0068] Spectral composition: Cu59.50%, Pb1.50%, Al0.35%, Fe0.25%, Sn0.2%, Ni0.04%, the balance is Zn, the B content is 11ppm, the finished product produced by the above process has a cutting performance of 87% of HPb63-3, the cutting end morphology is a small crescent, the machined surface roughness is 0.05um, the mirror effect is significant, and the welding wetting effect is good. The particle diameter of Fe3Al, FeB and Al2B is 2nm, and the crystal plane distance of brass in the most densely packed (111) plane direction is 0.15nm, <110> The number of particles per unit area in the most densely packed direction is 4500 / mm 2 The crystal plane distance in the (110) plane direction is 0.2nm; the crystal plane distance in the (100) plane direction is 0.2nm, which ensures the sufficient solid solution or nucleation and growth of the second phase nucleus particles.

[0069] Figure 2 The microscopic metallographic image of the brass rod prepared in Example 1 is shown in FIG. Figure 2 It can be seen that the grain structure of the brass rod prepared in this embodiment is relatively fine, consisting of а phase and β phase, and there are local dendrites. This may be due to the influence of a certain temperature gradient in the cooling process, and the grain size is generally uniform.

[0070] Figure 3 The wetting angle (5.17°) of the brass rod prepared in Example 1 during welding is obtained by Figure 3 It can be seen that after welding, the bonding between the solder and the substrate is relatively dense, and the solder wetting angle is smooth and uniform.

[0071] Example 2

[0072] The alloy composition of this embodiment is: Cu60.50%, Pb1.70%, Al0.38%, Fe0.27%, Sn0.2%, Ni0.04%, Zn balance, and B content is 12ppm. A special refiner X for brass (potassium fluoroborate 70%, potassium fluorosilicate 20%, potassium fluorotitanate 10%) is configured, and the addition amount of refiner X is 0.03% of the total amount of the charge.

[0073] Produced in 3t power frequency furnace Casting billet peeling production Rod.

[0074] Casting process:

[0075] 1. Add 2.5t of processed recycled materials into the industrial frequency furnace in two batches. First, add 1.5t of recycled materials into the furnace. After the recycled materials are completely melted, add the remaining 1t of processed recycled materials into the furnace. After the recycled materials are completely melted, keep them warm at 980℃-1020℃.

[0076] 2. After the insulation is completed, the furnace temperature is increased to 1050℃-1080℃, and the flame is sprayed for about 1 minute. The refining agent is added into the furnace and then stirred. After stirring, the slag in the furnace can be cleaned up, and the temperature is lowered to 1000℃-1030℃. Samples are taken for spectrum testing. At the same time, 800g of refiner X is pressed into the furnace with a pressing spoon, stirred for 1 minute, and then kept warm and still. If the spectrum test is qualified, traction casting can be arranged.

[0077] 3. If the spectrum test component is qualified, arrange the traction, the traction speed is 290mm / min, the traction temperature is 1030-1040℃, the ingot specifications In the casting process of this embodiment, secondary water ring cooling is adopted, and the primary cooling water flow rate is 30m 3 / h, the secondary cooling water flow rate is 25m 3 / h, the water ring spacing is 150mm, the water pressure is 0.4-0.6MPa, the water inlet temperature is 20-40℃, the water outlet temperature is 40-60℃, the temperature of the continuous casting rod out of the crystallizer is 550-650℃, and the temperature of the cast rod after secondary cooling is 15-30℃.

[0078] Wire drawing process:

[0079] The rough material is directly pulled onto the straight pull car for peeling to produce semi-finished products.

[0080] Stress relief annealing:

[0081] The rod is subjected to stress relief heating annealing at a temperature of 300°C for 3 hours.

[0082] Grinding process:

[0083] The ground rods after annealing are continuously polished with a polishing wheel, and the roughness of the polished rods is less than 0.045um.

[0084] Careful inspection and storage.

[0085] Customer welding: In the actual welding process, the cooling temperature needs to be based on the actual efficiency requirements, and the air cooling time is extended to 19s for water cooling.

[0086] The alloy composition and microstructure parameters of the product of this embodiment are shown in Table 1 and Table 2 respectively.

[0087] Spectral composition: Cu60.50%, Pb1.70%, Al0.38%, Fe0.27%, Sn0.2%, Ni0.04%, Zn remainder, B content is 12ppm, the finished product produced by the above process has a cutting performance of 90% of HPb63-3, the cutting end morphology is a small crescent shape, the machined surface roughness is 0.045um, the mirror effect is significant, and the welding wetting effect is good. The diameter of Fe3Al, FeB and Al2B particles is 3nm, and the crystal plane distance of brass in the most densely packed (111) plane direction is 0.18nm, <110> The number of particles per unit area in the most densely packed direction is 5000 / mm 2 The crystal plane distance in the (110) plane direction is 0.15 nm; the crystal plane distance in the (100) plane direction is 0.15 nm, ensuring sufficient solid solution or nucleation and growth of the second phase nucleus particles.

[0088] Figure 4 The microscopic metallographic image of the brass rod prepared in Example 2 is shown in FIG. Figure 4 It can be seen that the grain structure of the brass rod prepared in this embodiment is relatively fine, composed of а phase and β phase, mainly presents short rod and island distribution, and is evenly distributed.

[0089] Figure 5 The wetting angle (6.87°) of the brass rod prepared in Example 2 during welding is obtained by Figure 5 It can be seen that after welding, the bonding between the solder and the substrate is relatively dense, and the solder wetting angle is smooth and uniform.

[0090] Example 3

[0091] The alloy composition of this embodiment is Cu57.50%, Pb1.90%, Al0.37%, Fe0.28%, Sn0.2%, Ni0.02%, Zn balance, and B content is 10ppm. A special refiner X for brass (potassium fluoroborate 70%, potassium fluorosilicate 20%, potassium fluorotitanate 10%) is configured, and the addition amount of refiner X is 0.03% of the total amount of the charge.

[0092] Produced in 3t power frequency furnace Casting billet peeling production Rod.

[0093] Casting process:

[0094] 1. Add 2.5t of processed recycled materials into the industrial frequency furnace in two batches. First, add 1.5t of recycled materials into the furnace. After the recycled materials are completely melted, add the remaining 1t of processed recycled materials into the furnace. After the recycled materials are completely melted, keep them warm at 980℃-1020℃.

[0095] 2. After the insulation is completed, the furnace temperature is increased to 1050℃-1080℃, and the flame is sprayed for about 1 minute. The refining agent is added into the furnace and then stirred. After stirring, the slag in the furnace can be cleaned up, and the temperature is lowered to 1000℃-1030℃. Samples are taken for spectrum testing. At the same time, 800g of refiner X is pressed into the furnace with a pressing spoon, stirred for 1 minute, and then kept warm and still. If the spectrum test is qualified, traction casting can be arranged.

[0096] 3. If the spectrum test component is qualified, arrange the traction, the traction speed is 360mm / min, the traction temperature is 1030-1040℃, the ingot specifications In the casting process of this embodiment, secondary water ring cooling is adopted, and the primary cooling water flow rate is 35m 3 / h, the secondary cooling water flow rate is 30m 3 / h, water ring spacing 150mm, water pressure 0.4-0.6MPa, water inlet temperature 20-40℃, water outlet temperature 40-60℃, continuous casting rod outlet temperature of crystallizer 550-650℃, and casting rod temperature after secondary cooling is 15-30℃.

[0097] Wire drawing process:

[0098] The rough material is directly pulled onto the straight pull car for peeling to produce semi-finished products.

[0099] Stress relief annealing:

[0100] The rod is subjected to stress relief heating annealing at a temperature of 300°C for 3 hours.

[0101] Grinding process:

[0102] The ground rods after annealing are continuously polished with a polishing wheel, and the roughness of the polished rods is less than 0.04um.

[0103] Careful inspection and storage.

[0104] Customer welding: In the actual welding process, the cooling temperature needs to be based on the actual efficiency requirements, and the air cooling time is extended to 21s for water cooling.

[0105] The alloy composition and microstructure parameters of the product of this embodiment are shown in Table 1 and Table 2 respectively.

[0106] Spectral composition: Cu57.50%, Pb1.90%, Al0.37%, Fe0.28%, Sn0.2%, Ni0.02%, Zn remainder, B content is 10ppm, the finished product produced by the above process has a cutting performance of 85% of HPb63-3, the cutting end morphology is a small crescent shape, the machined surface roughness is 0.04um, the mirror effect is significant, and the welding wetting effect is good. The particle diameter of Fe3Al, FeB and Al2B is 4nm, and the crystal plane distance of brass in the most densely packed (111) plane direction is 0.15nm, <110> The number of particles per unit area in the most densely packed direction is 5200 / mm 2 The crystal plane distance in the (110) plane direction is 0.17 nm; the crystal plane distance in the (100) plane direction is 0.17 nm, ensuring sufficient solid solution or nucleation and growth of the second phase nucleus particles.

[0107] Figure 6 The microscopic metallographic image of the brass rod prepared in Example 3 is shown in FIG. Figure 6 It can be seen that the grain structure of the brass rod prepared in this embodiment is relatively fine, composed of а phase and β phase, mainly distributed in short rod and island shapes, with certain fine dendrites locally and evenly distributed.

[0108] Figure 7 The wetting angle (5.25°) of the brass rod prepared in Example 3 during welding is obtained by Figure 7 It can be seen that after welding, the bonding between the solder and the substrate is relatively dense, and the solder wetting angle is smooth and uniform.

[0109] Comparative Example 1

[0110] The alloy composition of this comparative example is: Cu 58.50%, Pb 1.85%, Al 0.33%, Fe 0.20%, Sn 0.2%, Ni 0.02%, and Zn balance.

[0111] Produced in 3t power frequency furnace Casting billet peeling production Rod.

[0112] Casting process:

[0113] 1. Add 2.5t of processed recycled materials into the industrial frequency furnace in two batches. First, add 1.5t of recycled materials into the furnace. After the recycled materials are completely melted, add the remaining 1t of processed recycled materials into the furnace. After the recycled materials are completely melted, keep them warm at 980℃-1020℃.

[0114] 2. After the insulation is completed, the furnace temperature is increased to 1050℃-1080℃, and the flame is sprayed for about 1 minute. The refining agent is added into the furnace and then stirred. After stirring, the slag in the furnace can be cleaned up, and the temperature is lowered to 1000℃-1030℃. Samples are taken for spectrum testing. At the same time, 800g of refiner (boron powder 95%, iron powder 5%) is pressed into the furnace with a pressing spoon, stirred for 1 minute, and then kept warm and still. If the spectrum test is qualified, traction casting can be arranged.

[0115] 3. If the spectrum test component is qualified, arrange the traction, the traction speed is 360mm / min, the traction temperature is 1030-1040℃, the ingot specifications

[0116] Wire drawing process:

[0117] The rough material is directly pulled onto the straight pull car for peeling to produce semi-finished products.

[0118] Stress relief annealing:

[0119] The rod is subjected to stress relief heating annealing at a temperature of 300°C for 3 hours.

[0120] Grinding process:

[0121] Careful inspection and storage.

[0122] Customer welding: In the actual welding process, the cooling temperature needs to be based on the actual efficiency requirements, and the air cooling time is about 5s for water cooling.

[0123] The alloy composition and microstructure parameters of the product of this comparative example are shown in Table 1 and Table 2 respectively.

[0124] Spectral composition: Cu58.50%, Pb1.85%, Al0.13%, Fe0.1%, Sn0.2%, Ni0.02%, Zn remainder. The finished product produced by the above process has a cutting performance of 90% of HPb63-3, and the cutting end morphology is a small crescent shape, the machined surface roughness is 0.7um, the mirror diffuse reflection is serious, the mirror is blurred, and the welding wetting effect is poor. The diameter of Fe3Al, FeB and Al2B particles is 20nm, and the crystal plane distance of brass in the most densely packed (111) plane direction is 0.5nm. <110> The number of particles per unit area in the most densely packed direction is 1200 / mm 2 The crystal plane distance in the (110) plane direction is 0.2nm; the crystal plane distance in the (100) plane direction is 0.2nm, which ensures the sufficient solid solution or nucleation and growth of the second phase nucleus particles.

[0125] Figure 8 The microscopic metallographic image of the brass rod prepared in Comparative Example 1 is Figure 8It can be seen that the metallographic interface grain structure of the brass rod prepared in this comparative example is coarse, composed of а phase and β phase, and mainly presents a large isolated island grain morphology distribution.

[0126] Fig. 9 The wetting angle (40.53°) of the brass rod prepared in comparative example 1 during welding was obtained by Fig. 9 It can be seen that after welding, the bonding between the solder and the substrate is relatively loose, and the solder has significant pores and slag inclusion problems, and the solder wetting angle is steep.

[0127] Table 1 Composition of alloy bars of the embodiments of the present invention and the comparative examples (wt%)

[0128]

[0129] Table 2 Microstructure and properties of alloy bars of the embodiments of the present invention and the comparative examples

[0130]

Claims

1. A brass bar with high wettability for welding, It is characterized in that The invention comprises the following components in percentage by weight: Cu: 57-61%, Pb: 1.0-2.0%, Al: 0.1-0.4%, Fe: 0.1-0.3%, B: 10-20ppm, Sn<0.5%, Ni<0.1%, and the balance is Zn and unavoidable impurities; the welding high wettability brass rod comprises Fe 3 Al, FeB and Al 2 B. Crystal core particles, wherein the diameter of the crystal core particles is 1 to 5 nm.

2. The brass rod with high wettability for welding according to claim 1, It is characterized in that The crystal nucleus particles satisfy the following conditions in the (111) most densely packed plane direction: 0.15nm < crystal plane distance < 0.2nm; in the (110) plane direction: 0.2nm < crystal plane distance < 0.25nm; in the (100) plane direction: 0.2nm < crystal plane distance < 0.25nm; the number of crystal nucleus particles per unit area in the most densely packed direction is 2000-6000 / mm 2 .

3. The brass rod with high wettability for welding according to claim 1, It is characterized in that In the brass rod with high wettability for welding, the mass ratio of Fe, Al and B is 20000-30000:30000-40000:

1.

4. The brass rod with high wettability for welding according to claim 1, It is characterized in that The roughness of the brass rod with high wettability for welding is ≤0.05um; the wetting angle of the brass rod with high wettability for welding during welding is 5-7°.

5. A method for preparing a brass bar with high wettability for welding according to any one of claims 1 to 4, It is characterized in that The process includes the following steps: batching → melting and casting → wire drawing → annealing → grinding; Wherein, in the melting and casting process, the refiner used is a mixture of potassium fluoroborate, potassium fluorotitanate and potassium fluorosilicate; In the melting and casting process, secondary water ring cooling is adopted, the temperature of the rod out of the crystallizer is 550-650°C, and the temperature of the rod after secondary water ring cooling is 15-30°C.

6. The preparation method according to claim 5, It is characterized in that In the refiner, the mass ratio of potassium fluoroborate, potassium fluorotitanate and potassium fluorosilicate is 6-8:1-2:2-4; and the added amount of the refiner is 0.02-0.05% of the total mass of the raw materials.

7. The preparation method according to claim 5, It is characterized in that The secondary water ring cooling is carried out in a water ring cooling device, which includes a first water ring and a second water ring with a spacing of 50 to 200 mm. The first water ring and the second water ring are provided with water inlets, and the inner wall of the water ring is provided with a plurality of water spray holes with the water spray direction inclined downward; during the cooling process, cooling water is sprayed out from the water spray holes to cool the rods passing through the center of the first water ring and the second water ring in sequence.

8. The preparation method according to claim 5 or 7, It is characterized in that In the secondary water ring cooling process, the primary cooling water flow rate is 10-40m 3 / h, the secondary cooling water flow rate is 1~30m 3 / h, water pressure is 0.4~0.6MPa, water inlet temperature is 20~40℃, and water outlet temperature is 40~60℃.

9. The preparation method according to claim 5, It is characterized in that In the grinding process, the roughness of the rod is controlled to be below 0.05um.

10. Use of the brass rod with high wettability for welding according to any one of claims 1 to 4 in the preparation of electronic appliances, instruments and meters, or hardware and sanitary ware accessories.

11. The use according to claim 10, It is characterized in that During the application process, the brass rod with high wettability is welded, and after the welding is completed, the obtained welding material is air-cooled for 10 to 25 seconds and then water-cooled.

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