Method for producing high corrosion-resistant 3003+zinc alloy blank with green low carbon and high stability

Abstract

The application belongs to the technical field of aluminum alloy production and specifically discloses a method for producing green low-carbon high-stability high-corrosion-resistance 3003+Zn alloy blank, which precisely controls alloy components on the basis of standard 3003 alloy, realizes the synergistic effect of sacrificial anode, solid solution strengthening and anti-segregation through Fe-Mn-Zn ternary synergistic strengthening and microstructure refinement, and has uniform microstructure, no segregation and no coarse brittle phase, optimal matching of strength and plasticity, and the like, so that the production cycle is greatly shortened, the short process, low cost, low carbon, high efficiency and high stability are realized, the 3003+Zn alloy blank is produced, and the corrosion resistance of the product can be greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy production technology, and specifically discloses a method for producing highly corrosion-resistant 3003+Zn alloy billets in a green, low-carbon, and highly stable manner. Background Technology

[0002] 3003 is an Al-Mn series aluminum alloy. Due to its good formability and brazing performance, it is suitable for heat exchange components. However, the strength of 3003 alloy drops sharply after recrystallization and softening during brazing. The material has weak post-weld strength and high-temperature collapse resistance, and is prone to intergranular corrosion and stress corrosion. The material has poor corrosion resistance and is at risk of leakage in long-term coolant / salt spray environments.

[0003] Production trials revealed that adding 0.8–1.8% Zn to the 3003 alloy for solid solution strengthening, sacrificial anode reinforcement, and brazing optimization effectively creates sacrificial anode protection, significantly improving corrosion resistance. Furthermore, the material strength increases by approximately 22.4 MPa, and brazing enhances its high-temperature deformation resistance. The improved alloy composition demonstrates significant improvements in strength, corrosion resistance, brazing performance, and anti-collapse properties, making it particularly suitable for precision heat exchange components such as radiators, heat exchangers, and composite aluminum foil. It is widely used in high-end heat exchange applications, including automotive radiators, air conditioning heat exchangers, battery water-cooled plates, and composite aluminum foil core materials.

[0004] 3003+Zn alloy billets are usually produced using the traditional ingot casting-hot rolling method. For example, the existing patent CN103103404B discloses a corrosion-resistant aluminum-manganese alloy and its preparation method. The production process includes multiple steps such as melting and casting, sawing and milling, hot rolling, cold rolling, and homogenization annealing. Before the hot rolling production process, sawing and milling must be performed, resulting in high losses, low yield, high production costs, and long production cycles. Summary of the Invention

[0005] To address the problems in the background art, this invention discloses a green, low-carbon, and highly stable method for producing highly corrosion-resistant 3003+Zn alloy billets, achieving short-process, low-cost, low-carbon, high-efficiency, and highly stable production of 3003+Zn alloy billets, and significantly improving the corrosion resistance of the products.

[0006] To achieve the above-mentioned objectives, the present invention employs the following technical solution: The specific steps for producing high-corrosion-resistant 3003+Zn alloy billets in a green, low-carbon, and highly stable manner are as follows: S1. Smelting: 45-55% recycled aluminum waste and 45-55% electrolytic aluminum liquid are added sequentially to the smelting furnace. After the solid waste is heated and leveled, the furnace temperature is raised to 720-740℃ and stirred for more than 20 minutes. Samples are taken for testing. Based on the test results, zinc ingots, iron agent, quick-dissolving silicon, manganese agent, copper agent, and titanium agent are added evenly to the smelting furnace in sequence. The alloy composition is adjusted to meet the requirements. The mass percentage of each component is as follows: Si: 0.2-0.4%, Fe: 0.3-0.5%, Mn: 1.1-1.4%, Zn: 1.4-1.6%, Cu: 0.07-0.12%, Ti: 0.015-0.035%, other individual impurities ≤0.03%, total ≤0.15%, and the balance is Al. S2. Melt Refining Treatment: The melt undergoes three refining processes in the melting furnace, with stirring during the refining process. Before refining, the melt temperature is raised to 735–750°C for 40 minutes. The first refining uses a granular refining agent at a dosage of 2 kg / ton. During refining, the refining head follows a Z+N shaped movement trajectory. After the first refining, the melt is stirred, slag is removed, and samples are taken for testing. Once the melt composition is confirmed to be homogeneous and the alloy composition is qualified, the second refining process begins. Before the second refining, the melt temperature is adjusted... The temperature is raised to 735-750℃, and a second refining is carried out using granular refining agent at a rate of 50kg per furnace. During refining, the refining head moves along a Z+N shaped trajectory. After refining, the mixture is stirred for a period of time and then the slag is removed. Before the third refining, the melt temperature is raised to 730-750℃, and high-purity argon is used for refining. The refining time is more than 15 minutes. During refining, the refining head moves along a Z+N shaped trajectory. After refining, the mixture is allowed to stand and the slag is removed. After removing the slag, the mixture is allowed to stand for more than 15 minutes before the furnace is started. S3. Addition of aluminum-titanium-boron wire: After refining, slag removal and settling treatment, the melt is brought to the furnace and flows smoothly into the guide channel. Aluminum-titanium-boron wire is added to the melt at several locations at a uniform speed. S4. Online degassing and filtration: After adding aluminum titanium boron wire, the melt enters the degassing box and the filtration box in sequence for online degassing and filtration. S5. Continuous casting: After online degassing and filtration, the melt flows into the forebox and then enters the casting cavity through the casting nozzle for continuous casting into a billet. The billet thickness × width × length is equal to 19mm × 1305mm × L. During continuous casting, the forebox temperature is 696±3℃, the casting cooling water temperature is 30±3℃, the pressure is 3.2±0.2Bar, the casting speed is 7.5±0.3m / min, the edge temperature of the strip at the outlet of the continuous casting machine is 565±10℃, and the middle temperature is 510±10℃. S6. Continuous rolling: The continuously cast billet enters the three-stand rolling mill through the looper to roll a strip with a thickness of 2.0 to 2.5 mm. During rolling, hot rolling emulsion with a mass percentage concentration of 3.0 ± 0.2% is sprayed to cool and lubricate the strip. The strip exits from the third stand of the three-stand rolling mill and is coiled into a coil on the coiler. S7. Inspection and Packaging: After the aluminum coils from the continuous rolling mill in step S6 are placed for 48 hours, samples are taken for mechanical property testing. If the test is qualified, the aluminum coils are packaged according to the packaging requirements.

[0007] Furthermore, in the method for producing high corrosion resistant 3003+Zn alloy billets in a green, low-carbon, and highly stable manner, in step S7, the longitudinal tensile strength of the finished product is 120 MPa to 140 MPa, and a 151±5g sample is subjected to a 50-hour salt spray corrosion test, with a weight gain not exceeding 0.005%.

[0008] Furthermore, in the method for producing high corrosion resistant 3003+Zn alloy billets in a green, low-carbon, and highly stable manner, in step S1, when adding zinc ingots, the zinc ingots are loaded into a feeding frame, and a feeding cart is used to immerse the feeding frame in the melt and shake it back and forth in the furnace area to completely melt the zinc ingots.

[0009] Furthermore, in the method for producing high corrosion resistant 3003+Zn alloy billets in a green, low-carbon, and highly stable manner, in step S2, after the first refining and slag removal, several samples are taken from both sides of the furnace door for testing, and the Zn content deviation in the samples does not exceed 0.02%.

[0010] Furthermore, in the method for producing high corrosion-resistant 3003+Zn alloy billets in a green, low-carbon, and highly stable manner, in step S3, four sets of aluminum-titanium-boron wires are added to the melt at a uniform speed and in equal amounts, with 1.5±0.3 kg of aluminum-titanium-boron wires added per ton of melt. An aluminum-titanium-boron wire stirring device is set at the point where the aluminum-titanium-boron wires are added, and the stirring device is submerged in the melt by more than 75 mm. The stirring frequency of the stirring device is 120±20 rpm.

[0011] Furthermore, in the method for producing high corrosion-resistant 3003+Zn alloy billets in a green, low-carbon, and highly stable manner, in step S4, the degassing box adopts a two-stage SNIF degassing box. The rotors of both stages of the SNIF degassing box operate at 500±50 rpm, and high-purity argon gas is introduced into the rotors as a refining agent at a flow rate of 50±2 L / min. The melt degassed by the two-stage SNIF degassing box flows into a two-stage plate filter box, which uses 30+40 mesh and 50+50 mesh ceramic filter plates respectively.

[0012] Furthermore, in the method for producing high corrosion-resistant 3003+Zn alloy billets in a green, low-carbon, and highly stable manner, in step S5, eight magnetic rollers are provided at the upper part of the continuous casting machine inlet, wherein the magnetic strength of the first two upper magnetic rollers is 50±1mT and the magnetic strength of the last six upper magnetic rollers is 30±1mT; five magnetic rollers are provided at the lower part of the continuous casting machine inlet, wherein the magnetic strength of the first two lower magnetic rollers is 50±1mT and the magnetic strength of the last three lower magnetic rollers is 30±1mT.

[0013] Furthermore, in the method for producing high corrosion-resistant 3003+Zn alloy billets in a green, low-carbon, and highly stable manner, the final rolling temperature of the strip at the exit of the three-roll mill is not lower than 260°C in step S6.

[0014] By adopting the above technical solution, the present invention has the following beneficial effects: 1. The green, low-carbon, and highly stable method for producing highly corrosion-resistant 3003+Zn alloy billets disclosed in this invention precisely controls the alloy composition to 0.3-0.5% Fe, 1.1-1.4% Mn, and 1.4-1.6% Zn based on the standard 3003 alloy. Through the ternary synergistic strengthening and microstructure refinement of Fe-Mn-Zn, the billet has a uniform microstructure, no segregation, and no coarse brittle phases. The strength and plasticity are optimally matched, achieving a synergistic effect of sacrificial anode + solid solution strengthening + anti-segregation. 2. The green, low-carbon, and highly stable method for producing highly corrosion-resistant 3003+Zn alloy billets disclosed in this invention adopts a continuous casting and rolling process to produce billets. This method involves fewer production steps, eliminates secondary heating, significantly shortens the production cycle, increases the unit time capacity by more than 40%, and reduces energy consumption by 25% to 40% compared to the traditional casting and hot rolling method. Furthermore, the continuous casting and rolling method eliminates the need for milling with a saw head, resulting in a yield rate that is about 5% higher. Overall, the continuous casting and rolling method reduces energy consumption by more than 35% and carbon emissions by more than 40% compared to the traditional hot rolling method, saving 450 to 800 yuan per ton. 3. The green, low-carbon, and highly stable method for producing highly corrosion-resistant 3003+Zn alloy billets disclosed in this invention produces billets with a final rolling temperature higher than the recrystallization start temperature, i.e., 250°C. After the billets are coiled, the residual heat from deformation provides the conditions for the recrystallization start temperature, enabling the billets to self-anneal. This facilitates the reduction of one intermediate annealing step in subsequent production, saving more than 260 kWh of electricity per ton, which can effectively reduce the production cost for customers. 4. The green, low-carbon, and highly stable method for producing highly corrosion-resistant 3003+Zn alloy billets disclosed in this invention uses magnetic rollers at both the top and bottom of the continuous casting machine inlet during continuous casting. The magnetic rollers attract the steel strip, reducing strip movement and ensuring the stability of the casting cavity. This avoids fluctuations in cooling conditions caused by casting cavity movement, which in turn affects the stability of the microstructure. At the same time, it eliminates casting shrinkage and porosity problems caused by insufficient melt filling due to casting cavity movement. Except for the head and tail scraps from the vertical plate production, there is no abnormal scrap loss throughout the production process, and the production process is stable and efficient. Detailed Implementation

[0015] The present invention will be further explained and illustrated below with reference to embodiments. However, this should not be construed as limiting the scope of protection of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. Example 1

[0016] The method for producing green, low-carbon, and highly stable 3003+Zn alloy billets with high corrosion resistance involves the following steps: S1. Smelting: Add 45% by mass of molten aluminum and 55% by mass of recycled aluminum scrap to the smelting furnace. During the feeding process, add solid materials first and then molten aluminum. After the solid scrap is heated and leveled, raise the furnace temperature to 725℃ and turn on the electromagnetic stirrer to stir for 28 minutes. Perform a sample test. According to the test results, add iron, quick-dissolving silicon, manganese, copper and titanium additives evenly to the smelting furnace in sequence. Use a charging cart to immerse the charging frame containing zinc ingots into the melt and shake it back and forth in the furnace area. The charging frame is immersed in the melt for 12 minutes to fully dissolve the zinc ingots. Adjust the alloy composition to meet the requirements. The mass percentage of each component is as follows: Si: 0.21%, Fe: 0.35%, Mn: 1.14%, Zn: 1.42%, Cu: 0.078%, Ti: 0.0159%, other individual impurities ≤0.03%, total ≤0.15%, balance Al. S2. Melt Refining Treatment: The melt undergoes three refining processes in the melting furnace, with the electromagnetic stirrer running throughout. The first refining uses granular refining agent. Before refining, the melt temperature is raised to 738℃ for 40 minutes. The amount of granular refining agent used is 2 kg per ton of melt. Refining is required to strictly follow a Z+N motion trajectory. After refining, stirring for 10 minutes is performed, followed by slag removal. After slag removal, samples are taken from both sides of the furnace door for composition retesting. The alloy composition is qualified, and the Zn content deviation in each sample is only 0.01%. Overall, the melt stirring is considered uniform. The composition is uniform and qualified; before the second refining, the melt is heated again to a furnace temperature of 745℃, and granular refining agent is used for the second refining, with a refining agent dosage of 50kg per furnace. The refining is required to strictly follow the Z+N motion trajectory. After the second refining is completed, the slag is removed after stirring for 10 minutes; before the third refining, the melt temperature is raised to 731℃, and high-purity argon is used for refining for 20 minutes. The refining is required to strictly follow the Z+N motion trajectory. After the third refining is completed, the melt is allowed to stand for 10 minutes before removing the slag, and after removing the slag, it is allowed to stand for 19 minutes before the furnace is opened. S3. Addition of aluminum-titanium-boron wire: After refining, slag removal and settling treatment, the melt is brought to the furnace and flows smoothly into the guide channel. Four sets of aluminum-titanium-boron wire are added to the melt at a uniform speed and in equal amounts. 1.3 kg of aluminum-titanium-boron wire is added per ton of melt. An aluminum-titanium-boron wire stirring device is installed at the addition point. The stirring frequency of the stirring device is 125 rpm and the stirring device is submerged in the melt by 85 mm. S4. Online degassing and filtration: The melt with added aluminum titanium boron wire enters the two-stage SNIF degassing box in the co-flow trough. The rotors of both SNIF degassing boxes are operated at 505 rpm. High-purity argon gas is introduced into the rotors as a refining agent. The purity of the high-purity argon gas is 99.9993%, and the argon gas flow rate is controlled at 52 L / min. The melt after being degassed by the two-stage SNIF degassing box enters the two-stage plate filter box for filtration. The filter box uses 30+40 mesh and 50+50 mesh ceramic filter plates respectively. S5. Continuous Casting: After online degassing and filtration, the melt flows into the front box and then enters the casting cavity through the casting nozzle for continuous casting into a billet. The magnetic strength of the first two magnetic rollers at the upper part of the continuous casting machine inlet is 49.5 mT, and the magnetic strength of the last six magnetic rollers is 30.2 mT. The magnetic strength of the first two magnetic rollers at the lower part is 50.7 mT, and the magnetic strength of the last three magnetic rollers is 29.8 mT. The billet size is 19 mm × 1305 mm × L, which means the billet thickness is 19 mm, the width is 1305 mm, and the length is L. The length of the billet is not fixed. During continuous casting, the front box temperature is controlled at 696℃, the casting cooling water temperature is 28℃, the pressure is 3.1 Bar, the casting speed is 7.4 m / min, and the edge temperature of the strip at the continuous casting machine outlet is 560℃, and the middle temperature is 505℃. S6. Continuous rolling: The continuously cast billet enters the three-stand rolling mill through the looper to roll a 2.1mm thick strip. The number of rolling passes is 19mm→9.1mm→4.3mm→2.1mm. During rolling, hot rolling emulsion with a mass percentage concentration of 3.0% is sprayed to cool and lubricate the strip. The final rolling temperature of the strip at the exit of the third stand is 268℃. The strip at the exit of the three stands needs to be coiled into coils on the coiler. S7. Inspection and Packaging: After the aluminum coils are placed on the machine for 48 hours, samples are taken for mechanical property testing. The longitudinal tensile strength of the finished aluminum strip is 129 MPa. A 150.251g sample is taken for 50 hours of salt spray corrosion testing to test its corrosion resistance. The weight gain during corrosion testing is 0.002%, which is considered qualified. The aluminum coils are then packaged according to the packaging requirements.

[0017] Salt spray corrosion resistance test procedure: A 150×150mm sample was weighed to obtain m1. The sample was placed in the salt spray chamber at an angle of 20°±5° to the vertical direction. The salt spray chamber temperature was set to 35±2℃, and the saturator temperature to 47℃. A 5% sodium chloride solution (by mass percentage) prepared with chemically pure or analytically pure sodium chloride and deionized water was used as the corrosive medium. The salt spray deposition rate in the salt spray chamber was set to be per 80cm. 2 The amount of salt spray deposition collected on the horizontal surface is 1.0 mL to 2.0 mL per hour. After running the salt spray test chamber for 50 hours, the sample is taken out and weighed to obtain m2. The corrosion weight gain is calculated as follows: corrosion weight gain = (m2 - m1) / m1 × 100%. If the corrosion weight gain is ≤ 0.005%, it is considered qualified. Example 2

[0018] The method for producing green, low-carbon, and highly stable 3003+Zn alloy billets with high corrosion resistance involves the following steps: S1. Smelting: Add 52% (by mass) of molten aluminum and 48% (by mass) of recycled aluminum scrap to the smelting furnace. During the feeding process, add the solid materials first, then the molten aluminum. After the solid scrap is heated and leveled, raise the temperature to 738℃ and turn on the electromagnetic stirrer to stir for 25 minutes. Perform a sample test. Based on the test results, add the iron agent, quick-dissolving silicon, manganese agent, copper agent, and titanium agent evenly to the smelting furnace in sequence. Use a charging cart to immerse the charging frame containing zinc ingots into the melt, shaking it back and forth in the furnace area. The charging frame should be immersed in the melt for 12 minutes to ensure the zinc ingots are fully dissolved. Adjust the alloy composition to meet the requirements. The mass percentages of each component are: Si: 0.35%, Fe: 0.48%, Mn: 1.32%, Zn: 1.58%, Cu: 0.11%, Ti: 0.032%, other individual impurities ≤0.03%, total ≤0.15%, balance Al. S2. Melt Refining Treatment: The melt undergoes three refining processes in the melting furnace. The electromagnetic stirrer must be kept running throughout the refining process. The first refining uses granular refining agent. Before refining, the melt temperature is raised to 747℃ for 40 minutes. The dosage of granular refining agent is 2 kg per ton of melt. The refining process must strictly follow a Z+N motion trajectory. After refining, the mixture is stirred for 10 minutes before slag removal. After slag removal, samples are taken from both sides of the furnace door for composition retesting. The alloy composition is qualified, and the Zn content in each sample is within acceptable limits. With a deviation of only 0.01%, the melt was judged to be uniformly stirred and of acceptable composition. Before the second refining, the melt was further heated to 745℃, and a granular refining agent was used for the second refining, with a dosage of 50kg per furnace. The refining was required to strictly follow the Z+N motion trajectory. After refining, the melt was stirred for 10 minutes and then the slag was removed. Before the third refining, the melt was further heated to 739℃, and high-purity argon was used for refining for 22 minutes. The refining was required to strictly follow the Z+N motion trajectory. After refining, the melt was allowed to stand for 10 minutes and then the slag was removed. After removing the slag, the melt was allowed to stand for at least 21 minutes before the furnace was opened. S3. Addition of aluminum-titanium-boron wire: After refining, slag removal and settling treatment, the melt is brought to the furnace and flows smoothly into the guide channel. Four sets of aluminum-titanium-boron wire are added to the melt at a uniform speed and in equal amounts. 1.6 kg of aluminum-titanium-boron wire is added per ton of melt. An aluminum-titanium-boron wire stirring device is installed at the addition point. The stirring frequency of the stirring device is 115 rpm and the stirring device is submerged in the melt by 80 mm. S4. Online degassing and filtration: The melt with added aluminum titanium boron wire enters the two-stage SNIF degassing box in a co-current trough. The rotors of both SNIF degassing boxes are operated at 525 rpm, and high-purity argon gas is introduced into the rotors as a refining agent. The purity of the high-purity argon gas is 99.9995%, and the argon gas flow rate is controlled at 49 L / min. The melt after being degassed by the two-stage SNIF degassing boxes enters the two-stage plate filter box. The filter boxes use 30+40 mesh and 50+50 mesh ceramic filter plates respectively. S5, Continuous Casting: The melt after online degassing and filtration flows into the forebox and then enters the casting cavity through the casting nozzle for continuous casting into a billet. The first two magnets at the upper part of the continuous casting machine inlet have a strength of 50.1 mT, and the last six magnets have a strength of 29.8 mT. The first two magnets at the lower part have a strength of 50.3 mT, and the last three magnets have a strength of 30.4 mT. The billet size is 19 mm × 1305 mm × L. During continuous casting, the forebox temperature is controlled at 699℃, the casting cooling water temperature is 32℃, the pressure is 3.3 Bar, the casting speed is 7.7 m / min, and the strip temperature at the outlet of the continuous casting machine is 572℃, while the middle temperature is 518℃. S6. Continuous rolling: The continuously cast billet enters the three-roll mill through the looper to roll a 2.3mm thick strip. The number of rolling passes is 19mm→9.5mm→4.5mm→2.3mm. During rolling, a hot rolling emulsion with a mass percentage concentration of 3.2% is used to cool and lubricate the strip. The final rolling temperature of the strip at the exit of the three-roll mill is 263℃. The strip at the exit of the third stand needs to be coiled into coils on the coiler. S7. Inspection and Packaging: After the aluminum coils are placed on the machine for 48 hours, samples are taken for mechanical property testing. The longitudinal tensile strength of the finished aluminum strip is 131 MPa. A 150.392g sample is taken for 50 hours of salt spray corrosion testing to test its corrosion resistance. The weight gain during corrosion testing is 0.001%, which is considered qualified. The aluminum coils are then packaged according to the packaging requirements. Example 3

[0019] The method for producing green, low-carbon, and highly stable 3003+Zn alloy billets with high corrosion resistance involves the following steps: S1. Smelting: Add 55% by mass of molten aluminum and 45% by mass of recycled aluminum scrap to the smelting furnace. During the feeding process, add solid materials first and then molten aluminum. After the solid scrap is heated and leveled, raise the furnace temperature to 740℃, turn on the electromagnetic stirrer and stir for 20 minutes. Perform a sample test. According to the test results, add iron, quick-dissolving silicon, manganese, copper and titanium additives evenly to the smelting furnace in sequence. Use a charging cart to immerse the charging frame containing zinc ingots into the melt and shake it back and forth in the furnace area. The charging frame is immersed in the melt for 12 minutes to fully dissolve the zinc ingots. Adjust the alloy composition to meet the requirements. The mass percentage of each component is as follows: Si: 0.29%, Fe: 0.48%, Mn: 1.33%, Zn: 1.54%, Cu: 0.096%, Ti: 0.021%, other individual impurities ≤0.03%, total ≤0.15%, balance Al. S2. Melt Refining Treatment: The melt undergoes three refining processes in the melting furnace. The electromagnetic stirrer is kept running throughout the refining process. The first refining uses granular refining agent. Before refining, the melt temperature is raised to 741℃ for 40 minutes. The dosage of the granular refining agent is 2 kg per ton of melt. The refining process strictly follows a Z+N motion trajectory. After refining, the melt is stirred for 10 minutes before slag removal. After slag removal, samples are taken from both sides of the furnace door for composition retesting. The alloy composition is qualified, and the Zn content deviation in each sample is only 0.01%. Overall, the melt stirring is considered uniform. The composition is uniform and qualified; before the second refining, the melt is heated again to a furnace temperature of 744℃, and granular refining agent is used for the second refining, with a refining agent dosage of 50kg per furnace. The refining is required to strictly follow the Z+N motion trajectory. After the second refining is completed, the slag is removed after stirring for 10 minutes; before the third refining, the melt temperature is raised to 737℃, and high-purity argon is used for refining for 20 minutes. The refining is required to strictly follow the Z+N motion trajectory. After the third refining is completed, the melt is allowed to stand for 10 minutes before removing the slag, and after removing the slag, it is allowed to stand for 19 minutes before the furnace is opened. S3. Addition of aluminum-titanium-boron wire: After refining, slag removal and settling treatment, the melt is brought to the furnace and flows smoothly into the guide channel. Four sets of aluminum-titanium-boron wire are added to the melt at a uniform speed and in equal amounts. 1.8 kg of aluminum-titanium-boron wire is added per ton of melt. An aluminum-titanium-boron wire stirring device is installed at the addition point. The stirring frequency of the stirring device is 130 rpm and the stirring device is submerged in the melt by 85 mm. S4. Online degassing and filtration: The melt with added aluminum titanium boron wire enters the two-stage SNIF degassing box in the co-flow trough. The rotors of both SNIF degassing boxes are operated at 505 rpm. High-purity argon gas is introduced into the rotors as a refining agent. The purity of the high-purity argon gas is 99.9993%, and the argon gas flow rate is controlled at 52 L / min. The melt after being degassed by the two-stage SNIF degassing box enters the two-stage plate filter box for filtration. The filter box uses 30+40 mesh and 50+50 mesh ceramic filter plates respectively. S5, Continuous Casting: After online degassing and filtration, the melt flows into the forebox and then enters the casting cavity through the casting nozzle for continuous casting into a billet. The magnetic strength of the first two magnetic rollers at the upper part of the continuous casting machine inlet is 49.5 mT, and the magnetic strength of the last six magnetic rollers is 30.2 mT. The magnetic strength of the first two magnetic rollers at the lower part is 50.7 mT, and the magnetic strength of the last three magnetic rollers is 29.8 mT. The billet size is 19 mm × 1305 mm × L. During continuous casting, the forebox temperature is controlled at 693℃, the casting cooling water temperature is 30℃, the pressure is 3.0 Bar, the casting speed is 7.2 m / min, and the edge temperature of the strip at the continuous casting machine outlet is 565℃, and the middle temperature is 505℃. S6. Continuous rolling: The continuously cast billet enters the three-roll mill through the looper to roll a 2.5mm thick strip. The number of rolling passes is 19mm→9.3mm→4.6mm→2.5mm. During rolling, hot rolling emulsion with a mass percentage concentration of 3.0% is sprayed to cool and lubricate the strip. The final rolling temperature of the strip at the exit of the third continuous rolling mill is 270℃. The strip at the exit of the three stands needs to be coiled into coils on the coiler. S7. Inspection and Packaging: After the aluminum coils are placed on the machine for 48 hours, samples are taken for mechanical property testing. The longitudinal tensile strength of the finished aluminum strip is 131 MPa. A 148.463g sample is taken for 50 hours of salt spray corrosion testing to test its corrosion resistance. The weight gain during corrosion testing is 0.001%, which is considered qualified. The aluminum coils are then packaged according to the packaging requirements.

[0020] The parts of this invention not described in detail are prior art.

[0021] The embodiments selected herein for the purpose of disclosing the inventive objectives are currently considered suitable; however, it should be understood that the invention is intended to include all variations and modifications of the embodiments that fall within the scope of this concept and invention.

Claims

1. A green, low-carbon, and highly stable method for producing highly corrosion-resistant 3003+Zn alloy billets, characterized by: The specific steps are as follows: S1. Smelting: 45-55% recycled aluminum waste and 45-55% electrolytic aluminum liquid are added sequentially to the smelting furnace. After the solid waste is heated and leveled, the furnace temperature is raised to 720-740℃ and stirred for more than 20 minutes. Samples are taken for testing. Based on the test results, zinc ingots, iron agent, quick-dissolving silicon, manganese agent, copper agent, and titanium agent are added evenly to the smelting furnace in sequence. The alloy composition is adjusted to meet the requirements. The mass percentage of each component is as follows: Si: 0.2-0.4%, Fe: 0.3-0.5%, Mn: 1.1-1.4%, Zn: 1.4-1.6%, Cu: 0.07-0.12%, Ti: 0.015-0.035%, other individual impurities ≤0.03%, total ≤0.15%, and the balance is Al. S2. Melt Refining Treatment: The melt undergoes three refining processes in the melting furnace, with stirring during the refining process. Before refining, the melt temperature is raised to 735–750°C for 40 minutes. The first refining uses a granular refining agent at a dosage of 2 kg / ton. During refining, the refining head follows a Z+N shaped movement trajectory. After the first refining, the melt is stirred, slag is removed, and samples are taken for testing. Once the melt composition is confirmed to be homogeneous and the alloy composition is qualified, the second refining process begins. Before the second refining, the melt temperature is adjusted... The temperature is raised to 735-750℃, and a second refining is carried out using granular refining agent at a rate of 50kg per furnace. During refining, the refining head moves along a Z+N shaped trajectory. After refining, the mixture is stirred for a period of time and then the slag is removed. Before the third refining, the melt temperature is raised to 730-750℃, and high-purity argon is used for refining. The refining time is more than 15 minutes. During refining, the refining head moves along a Z+N shaped trajectory. After refining, the mixture is allowed to stand and the slag is removed. After removing the slag, the mixture is allowed to stand for more than 15 minutes before the furnace is started. S3. Addition of aluminum-titanium-boron wire: After refining, slag removal and settling treatment, the melt is brought to the furnace and flows smoothly into the guide channel. Aluminum-titanium-boron wire is added to the melt at several locations at a uniform speed. S4. Online degassing and filtration: After adding aluminum titanium boron wire, the melt enters the degassing box and the filtration box in sequence for online degassing and filtration. S5. Continuous casting: After online degassing and filtration, the melt flows into the forebox and then enters the casting cavity through the casting nozzle for continuous casting into a billet. The billet thickness × width × length is equal to 19mm × 1305mm × L. During continuous casting, the forebox temperature is 696±3℃, the casting cooling water temperature is 30±3℃, the pressure is 3.2±0.2Bar, the casting speed is 7.5±0.3m / min, the edge temperature of the strip at the outlet of the continuous casting machine is 565±10℃, and the middle temperature is 510±10℃. S6. Continuous rolling: The continuously cast billet enters the three-stand rolling mill through the looper to roll a strip with a thickness of 2.0 to 2.5 mm. During rolling, hot rolling emulsion with a mass percentage concentration of 3.0 ± 0.2% is sprayed to cool and lubricate the strip. The strip exits from the third stand of the three-stand rolling mill and is coiled into a coil on the coiler. S7. Inspection and Packaging: After the aluminum coils from the continuous rolling mill in step S6 are placed for 48 hours, samples are taken for mechanical property testing. If the test is qualified, the aluminum coils are packaged according to the packaging requirements.

2. The method for producing high corrosion-resistant 3003+Zn alloy billets with green, low-carbon, and high stability according to claim 1, characterized in that, In step S7, the longitudinal tensile strength of the finished product is 120 MPa to 140 MPa. A 151 ± 5 g sample is taken and subjected to a 50-hour salt spray corrosion test. The weight gain does not exceed 0.005%.

3. The method for producing high corrosion-resistant 3003+Zn alloy billets with green, low-carbon, and high stability according to claim 1, characterized in that, In step S1, when adding zinc ingots, the zinc ingots are loaded into the feeding frame, and the feeding cart is used to immerse the feeding frame in the melt and shake it back and forth in the furnace area to completely melt the zinc ingots.

4. The method for producing high corrosion-resistant 3003+Zn alloy billets with green, low-carbon, and high stability according to claim 1, characterized in that, In step S2, after the first refining and slag removal, several samples are taken from both sides of the furnace door for testing, and the Zn content deviation in the samples does not exceed 0.02%.

5. The method for producing high corrosion-resistant 3003+Zn alloy billets with green, low-carbon, and high stability according to claim 1, characterized in that, In step S3, four sets of aluminum-titanium-boron wires are added to the melt at a uniform speed and in equal amounts, with 1.5±0.3 kg of aluminum-titanium-boron wires added per ton of melt. An aluminum-titanium-boron wire stirring device is set at the point where the wires are added, and the stirring device is submerged in the melt by more than 75 mm. The stirring frequency of the stirring device is 120±20 rpm.

6. The method for producing high corrosion-resistant 3003+Zn alloy billets with green, low-carbon, and high stability according to claim 1, characterized in that, In step S4, the degassing box adopts a two-stage SNIF degassing box. The rotors of both SNIF degassing boxes are 500±50 rpm, and high-purity argon is introduced into the rotors as a refining agent with an argon flow rate of 50±2 L / min. The melt degassed by the two-stage SNIF degassing boxes flows into the dual-stage plate filter box. The dual-stage plate filter box uses 30+40 mesh and 50+50 mesh ceramic filter plates respectively.

7. The method for producing high corrosion-resistant 3003+Zn alloy billets with green, low-carbon, and high stability according to claim 1, characterized in that, In step S5, eight magnetic rollers are provided at the upper part of the continuous casting machine inlet, wherein the magnetic strength of the first two upper magnetic rollers is 50±1mT and the magnetic strength of the last six upper magnetic rollers is 30±1mT; five magnetic rollers are provided at the lower part of the continuous casting machine inlet, wherein the magnetic strength of the first two lower magnetic rollers is 50±1mT and the magnetic strength of the last three lower magnetic rollers is 30±1mT.

8. The method for producing high corrosion-resistant 3003+Zn alloy billets with green, low-carbon, and high stability according to claim 1, characterized in that, In step S6, the final rolling temperature of the strip at the exit of the three-roll mill shall not be lower than 260°C.