Method for preparing and detecting corrosion-resistant brass strip

Abstract

The invention relates to a corrosion-resistant brass strip preparation and detection method, and relates to the technical field of brass strip preparation, and the corrosion-resistant brass strip preparation and detection method comprises the following steps: S1, purchasing and detecting raw materials; s2, preparing materials; s3, smelting and casting; s4, hot rolling; s5, intermediate treatment; s6, cold rolling; s7, surface treatment; s8, performance detection; s9, treating a finished product; and S10, packaging and warehousing. According to the preparation and detection method for the corrosion-resistant brass strip, by adopting an arsenic-free multi-element microalloying technology, toxic arsenic oxide generated in the smelting process of traditional arsenic-containing brass is successfully avoided, pollution to the environment is remarkably reduced, and the increasingly strict environmental protection regulation requirements are met; by optimizing alloy components and a surface treatment process, such as adding tin, aluminum, boron, rare earth elements and the like, and adopting ultrasonic cleaning and passivating treatment, the corrosion resistance of the brass strip is remarkably improved, the service life of the brass strip in high-humidity and high-salinity environments such as ocean is remarkably prolonged, and the requirements of high-end application fields such as ocean engineering and shipbuilding are met.

Description

Technical Field

[0001] This invention relates to the field of brass strip preparation technology, specifically to a method for preparing and testing corrosion-resistant brass strip. Background Technology

[0002] Brass strip is an alloy material mainly composed of copper and zinc. Due to its good mechanical properties, machinability, and aesthetics, it has been widely used in many industrial fields. Brass strip not only has excellent electrical and thermal conductivity, but also exhibits high corrosion resistance, making it an ideal choice for manufacturing building hardware, pipe fittings, electrical components, etc. In addition, by adjusting the ratio of copper and zinc, and adding other alloying elements, the physical and chemical properties of brass strip can be further optimized to meet specific application requirements.

[0003] Traditional brass strip manufacturing methods mainly include several basic steps such as smelting and casting, rolling, and annealing. First, copper and zinc are mixed in a certain proportion and added to a smelting furnace for melting. If necessary, a small amount of other alloying elements are added to improve the material properties. After smelting, the molten alloy is poured directly into a mold to cool and form an ingot. Then, the ingot is thinned to the required thickness through a simple heating and rolling process, and may undergo an annealing treatment to eliminate internal stress. Finally, the finished strip usually only undergoes a simple surface cleaning treatment to complete the entire manufacturing process. Although this relatively simplified process can produce brass strip that basically meets the requirements, it has obvious limitations in accurately controlling the material composition, optimizing the microstructure, and improving corrosion resistance.

[0004] Market research data shows that traditional brass strip preparation methods have some significant drawbacks and shortcomings. On the one hand, although traditional arsenic-containing brass has good corrosion resistance, arsenic oxides (such as As2O3) are toxic and cause environmental pollution during the smelting process, which does not meet the requirements of modern environmental protection regulations. On the other hand, brass is prone to dezincification corrosion in marine environments, affecting the service life of the material, especially in marine engineering and aquaculture. In addition, traditional processes are difficult to effectively control the grain boundary structure, thus limiting further improvement in the material's corrosion resistance. With the increasing market demand for high-performance and environmentally friendly brass materials, traditional brass strip preparation methods can no longer fully meet current application needs and technical standards. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for preparing and testing corrosion-resistant brass strips, which has the advantages of high corrosion resistance, environmental friendliness and pollution-free production, and precise and controllable processes. It solves the problems of dezincification corrosion of traditional brass materials in marine environments, unstable product quality caused by rough production processes, and environmental pollution.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing and testing corrosion-resistant brass strip, comprising the following steps:

[0007] S1 Raw Material Procurement and Testing: After procuring raw materials such as copper, zinc, tin, aluminum, rare earth elements cerium and boron, the raw materials are screened after chemical composition analysis using a spectrometer.

[0008] S2 Ingredients: Weigh the ingredients according to the chemical composition ratio, put them into the ingredient container, and mix them evenly;

[0009] S3 Smelting and Casting: The prepared raw materials are added to the smelting furnace in batches. First, copper with a higher melting point is added, followed by zinc, tin, aluminum, boron and rare earth elements. The alloy liquid is stirred regularly. After smelting, the smelted alloy liquid is poured into the crystallizer of the continuous casting machine through a ladle for casting and then cut.

[0010] S4 hot rolling: The ingot is first placed in a heating furnace for preheating, and then the heated ingot is placed in a hot rolling mill for multi-pass rolling. During the rolling process, cooling water is used to cool the rolls.

[0011] S5 intermediate processing: The hot-rolled billet is put into a milling machine for milling to remove surface oxide scale and defects. Then the milled billet is put into a shearing machine for trimming to remove the edge parts. Finally, the trimmed billet is put into an annealing furnace for annealing.

[0012] S6 Cold Rolling: The annealed billet is placed into a cold rolling mill and subjected to 6 passes of rough rolling, with the thinning amount controlled at about 15% per pass and the rolling speed at 1.5 m / s. The strip after rough rolling is then placed into a cold rolling mill and subjected to 4 passes of finish rolling, with the thinning amount controlled at about 8% per pass and the rolling speed at 2.0 m / s. The final rolled thickness is 0.3 mm.

[0013] S7 Surface Treatment: The rolled strip is placed into the cleaning line for cleaning to remove surface oil and impurities. The temperature of the cleaning solution is controlled at about 55℃ and the cleaning time is 3 minutes. The cleaned strip is then placed into a chemical treatment tank for passivation treatment to form a dense oxide film.

[0014] S8 performance testing: Randomly sample the finished strip, process the sample into a form suitable for testing, put it into a spectrometer for testing, and then put it into a universal testing machine and a salt spray test chamber for testing.

[0015] S9 Finished Product Processing: The finished strip is placed into a tension leveling machine for tension leveling to eliminate residual stress and improve the flatness of the strip. The tension leveling force is controlled at 30kN and the tension leveling speed is 1.5m / min. The tension leveled strip is then placed into a cutting machine for cutting, and the cutting speed is controlled at 1.5m / min.

[0016] S10 Packaging and Warehousing: The cut strips are placed into the packaging machine for roll packaging. Forklifts are used to move the packaged strips to the warehouse, where they are stored according to batch and specifications.

[0017] Furthermore, the percentage mass of the raw materials procured in step S1, raw material procurement and testing, is as follows:

[0018] Copper (Cu): 65%;

[0019] Zinc (Zn): 30%;

[0020] Tin (Sn): 20%;

[0021] Aluminum (Al): 10%;

[0022] Rare earth element (cerium, Ce): 3%;

[0023] Boron (B): 1%.

[0024] Furthermore, during the melting and casting process in step S3, the medium-frequency induction melting furnace is gradually heated to 1100℃ and maintained at that temperature for 1.5 hours under argon protection with a flow rate of 0.5-1.0L / min; the casting temperature of the continuous casting machine in step S3 is 1020℃, the casting speed is 0.8m / min, and the cooling water temperature is 25℃.

[0025] Furthermore, during the hot rolling process in step S4, the heating furnace is heated to 920°C and maintained for 1.5 hours; in step S4, the hot rolling mill performs 4 passes of rolling, with a thinning amount of 25% per pass, and the rolling temperature is controlled at 880°C and the rolling speed is 0.8m / s.

[0026] Furthermore, during the intermediate processing in step S5, the milling depth is controlled to be 1.5 mm and the milling speed is 0.8 m / min; the trimming width is controlled to be 8 mm and the trimming speed is 0.8 m / min; the annealing furnace is used to gradually heat up to 620°C and maintain the temperature for 1.5 hours.

[0027] Furthermore, in the surface treatment process of step S7, the passivation solution consists of 5% nitric acid, 3% phosphoric acid, and 2% chromic acid. The passivation time at room temperature is 8 minutes, and the passivation film thickness is 1.5 μm.

[0028] Furthermore, during the performance testing process in step S8, the universal testing machine tests the following: tensile strength 420MPa, elongation 35%, hardness 120HV, and salt spray test in a salt spray chamber, with the corrosion and oxidation area not exceeding 5% after 48 hours.

[0029] Furthermore, in step S10, during the packaging and warehousing process, when the packaged strip is stored in the warehouse, a distance of at least 5cm is maintained between two adjacent rolls of strip, and no more than 5 rolls are stored on each layer. At the same time, the warehouse is equipped with an automatic temperature and humidity monitoring and control system, with the temperature controlled at 18-22℃ and the humidity controlled at 40-50%RH.

[0030] Furthermore, in step S3, during the melting and casting process, when the melting furnace is heated to 1100°C, the heating is paused and maintained at 800°C for 30 minutes to allow the raw materials in the furnace to be fully preheated and evenly heated. Then, the temperature is raised to 1100°C and maintained for 1.5 hours. Meanwhile, during the casting process on the continuous casting machine, when the ingot length reaches 80% of the set value, the casting speed is reduced to 0.6 m / min in advance and maintained for 1 minute before the cutting operation is performed.

[0031] Furthermore, in step S7 surface treatment, before passivation, an ultrasonic cleaning process is performed. The cleaned strip is placed in an ultrasonic cleaning tank and ultrasonic cleaning is performed using deionized water. The cleaning time is 5-10 minutes, the ultrasonic frequency is 28-40kHz, and the cleaning temperature is 40-50℃.

[0032] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0033] 1. The method for preparing and testing corrosion-resistant brass strip utilizes arsenic-free multi-element microalloying technology. This application successfully avoids the toxic arsenic oxides generated during the smelting process of traditional arsenic-containing brass, significantly reducing environmental pollution and meeting increasingly stringent environmental regulations. Furthermore, by optimizing the alloy composition and surface treatment process, such as adding tin, aluminum, boron, and rare earth elements, and employing ultrasonic cleaning and passivation treatment, the corrosion resistance of the brass strip is significantly improved, especially its service life in high-humidity and high-salt environments such as the ocean, meeting the needs of high-end application fields such as marine engineering and shipbuilding.

[0034] 2. This method for preparing and testing corrosion-resistant brass strip, through precise control of key process parameters such as smelting, casting, hot rolling, and cold rolling, not only improves production efficiency and reduces production costs, but also ensures the high quality and consistency of the strip. For example, the introduction of a preheating step and argon protection during the smelting process effectively improves the purity and uniformity of the alloy liquid; during the rolling process, the mechanical properties of the material are further improved by optimizing temperature and speed parameters. These improvements enable the corrosion-resistant brass strip of this application to meet high-performance requirements while possessing higher economic efficiency and market competitiveness. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the preparation and detection steps of the present invention. Detailed Implementation

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] Please see Figure 1 The method for preparing and testing corrosion-resistant brass strip in this embodiment includes the following steps:

[0038] S1 Raw Material Procurement and Testing: After procuring raw materials such as copper, zinc, tin, aluminum, rare earth elements cerium and boron, the raw materials are screened after chemical composition analysis using a spectrometer.

[0039] S2 Ingredients: Weigh the ingredients according to the chemical composition ratio, put them into the ingredient container, and mix them evenly;

[0040] S3 Smelting and Casting: The prepared raw materials are added to the smelting furnace in batches. First, copper with a higher melting point is added, followed by zinc, tin, aluminum, boron and rare earth elements. The alloy liquid is stirred regularly. After smelting, the smelted alloy liquid is poured into the crystallizer of the continuous casting machine through a ladle for casting and then cut.

[0041] S4 hot rolling: The ingot is first placed in a heating furnace for preheating, and then the heated ingot is placed in a hot rolling mill for multi-pass rolling. During the rolling process, cooling water is used to cool the rolls.

[0042] S5 intermediate processing: The hot-rolled billet is put into a milling machine for milling to remove surface oxide scale and defects. Then the milled billet is put into a shearing machine for trimming to remove the edge parts. Finally, the trimmed billet is put into an annealing furnace for annealing.

[0043] S6 Cold Rolling: The annealed billet is placed into a cold rolling mill and subjected to 6 passes of rough rolling, with the thinning amount controlled at about 15% per pass and the rolling speed at 1.5 m / s. The strip after rough rolling is then placed into a cold rolling mill and subjected to 4 passes of finish rolling, with the thinning amount controlled at about 8% per pass and the rolling speed at 2.0 m / s. The final rolled thickness is 0.3 mm.

[0044] S7 Surface Treatment: The rolled strip is placed into the cleaning line for cleaning to remove surface oil and impurities. The temperature of the cleaning solution is controlled at about 55℃ and the cleaning time is 3 minutes. The cleaned strip is then placed into a chemical treatment tank for passivation treatment to form a dense oxide film.

[0045] S8 performance testing: Randomly sample the finished strip, process the sample into a form suitable for testing, put it into a spectrometer for testing, and then put it into a universal testing machine and a salt spray test chamber for testing.

[0046] S9 Finished Product Processing: The finished strip is placed into a tension leveling machine for tension leveling to eliminate residual stress and improve the flatness of the strip. The tension leveling force is controlled at 30kN and the tension leveling speed is 1.5m / min. The tension leveled strip is then placed into a cutting machine for cutting, and the cutting speed is controlled at 1.5m / min.

[0047] S10 Packaging and Warehousing: The cut strips are placed into the packaging machine for roll packaging. Forklifts are used to move the packaged strips to the warehouse, where they are stored according to batch and specifications.

[0048] It should be noted that the entire production process, from raw material procurement to finished product warehousing, has been comprehensively optimized. By precisely controlling the process parameters of each step, such as melting temperature, rolling speed, and surface treatment conditions, the high quality and high performance of brass strip have been ensured, meeting the market's stringent requirements for corrosion-resistant brass strip.

[0049] The percentage mass of raw materials procured in step S1, raw material procurement and testing, is as follows:

[0050] Copper (Cu): 65%;

[0051] Zinc (Zn): 30%;

[0052] Tin (Sn): 20%;

[0053] Aluminum (Al): 10%;

[0054] Rare earth element (cerium, Ce): 3%;

[0055] Boron (B): 1%.

[0056] It should be noted that by rationally proportioning components such as copper, zinc, tin, aluminum, rare earth elements cerium and boron, the performance of brass strip has been optimized. This not only improves the material's corrosion resistance but also takes into account its strength and processing performance, providing a good foundation for the implementation of subsequent processes.

[0057] In step S3, during the melting and casting process, the medium-frequency induction melting furnace is gradually heated to 1100℃ and maintained at that temperature for 1.5 hours under argon protection with a flow rate of 0.5-1.0L / min. In step S3, the continuous casting machine has a casting temperature of 1020℃, a casting speed of 0.8m / min, and a cooling water temperature of 25℃.

[0058] It should be noted that during the melting and casting process, a medium-frequency induction melting furnace is used to gradually raise the temperature to 1100℃ and maintain the temperature for 1.5 hours. At the same time, argon gas protection is used to effectively prevent the oxidation of the alloy liquid and ensure the purity and uniformity of the alloy composition. The precise control of the casting temperature, speed and cooling water temperature of the continuous casting machine further guarantees the quality of the ingot and provides high-quality billets for the subsequent rolling process.

[0059] In step S4, the heating furnace is heated to 920°C and maintained for 1.5 hours during hot rolling. In step S4, the hot rolling mill performs 4 passes of rolling, with a thinning amount of 25% per pass. The rolling temperature is controlled at 880°C and the rolling speed is 0.8 m / s.

[0060] It should be noted that during the hot rolling process, the heating furnace is heated to 920℃ and maintained for 1.5 hours to ensure uniform heating of the ingot and avoid internal stress caused by uneven temperature. The hot rolling mill performs multiple rolling passes, and the precise control of the thinning amount and rolling temperature in each pass optimizes the microstructure of the strip and improves the mechanical properties and corrosion resistance of the material.

[0061] In step S5, during the intermediate processing, the milling depth is controlled to be 1.5 mm and the milling speed is 0.8 m / min; the trimming width is controlled to be 8 mm and the trimming speed is 0.8 m / min; the annealing furnace is used to gradually heat up to 620℃ and maintain the temperature for 1.5 hours.

[0062] It should be noted that the precise control of milling and trimming processes in the intermediate processing steps effectively removed the oxide scale and defects on the surface of the billet, ensuring the surface quality of the billet. The optimization of the annealing process eliminated work hardening, restored the plasticity of the material, and provided favorable conditions for the subsequent cold rolling process.

[0063] In step S7, the passivation solution consists of 5% nitric acid, 3% phosphoric acid, and 2% chromic acid. The passivation time at room temperature is 8 minutes, and the passivation film thickness is 1.5 μm.

[0064] It should be noted that the precise proportion of the passivation solution components and the strict control of the passivation time during the surface treatment process form a dense oxide film, which significantly improves the corrosion resistance of the brass strip. This surface treatment technology is particularly suitable for harsh environments such as the ocean, extending the service life of the material.

[0065] In step S8, the performance testing process involves the following parameters: tensile strength 420 MPa, elongation 35%, hardness 120 HV, and salt spray test in a salt spray chamber, with the corrosion and oxidation area not exceeding 5% after 48 hours.

[0066] It should be noted that during the performance testing phase, the finished strip was subjected to rigorous mechanical and corrosion resistance tests using a universal testing machine and a salt spray test chamber. This ensured the high quality and reliability of the product, providing a strong guarantee for its market competitiveness.

[0067] In step S10, during packaging and warehousing, the packaged strips are stored in the warehouse with a minimum 5cm gap between adjacent rolls and no more than 5 rolls per layer. The warehouse is equipped with an automatic temperature and humidity monitoring and control system, with the temperature controlled at 18-22℃ and the humidity controlled at 40-50%RH.

[0068] It should be noted that during the packaging and warehousing stage, by rationally arranging the storage spacing and number of layers of the strip materials and equipping them with an automatic temperature and humidity monitoring and control system, the stability of the warehouse environment is ensured, preventing the strip materials from oxidizing or getting damp during storage and guaranteeing the long-term quality stability of the products.

[0069] In step S3, during the melting and casting process, when the melting furnace is heated to 1100°C, the heating is paused and maintained at 800°C for 30 minutes to allow the raw materials in the furnace to be fully preheated and evenly heated. Then, the temperature is raised to 1100°C and maintained for 1.5 hours. Meanwhile, during the casting process on the continuous casting machine, when the ingot length reaches 80% of the set value, the casting speed is reduced to 0.6 m / min in advance and maintained for 1 minute before the cutting operation is performed.

[0070] It should be noted that the added preheating step and precise control of casting speed during the smelting and casting process further optimized the preheating effect of the alloy liquid and the cooling quality of the ingot. These improvements not only improved the internal quality of the ingot but also reduced defects such as cracks caused by excessively rapid cooling, thereby increasing the product qualification rate.

[0071] In step S7, surface treatment, before passivation, an ultrasonic cleaning process is performed. The cleaned strip is placed in an ultrasonic cleaning tank and ultrasonic cleaning is performed using deionized water. The cleaning time is 5-10 minutes, the ultrasonic frequency is 28-40kHz, and the cleaning temperature is 40-50℃.

[0072] It should be noted that the ultrasonic cleaning process added during the surface treatment stage effectively removes minute impurities and residual oil stains from the strip surface, improving the passivation effect and uniformity. This deep cleaning technology ensures the purity of the strip surface and further enhances the material's corrosion resistance.

[0073] This invention proposes a method for preparing and testing corrosion-resistant brass strip. Through meticulous management of the entire process—from raw material procurement and testing, batching, smelting and casting, hot rolling, intermediate processing, cold rolling, surface treatment to finished product processing and packaging—precise control and high-quality output are ensured at every stage. This method employs multi-element microalloying technology, adding tin, aluminum, boron, and rare earth elements to optimize the alloy structure. Strict process parameter control and advanced surface treatment technology significantly improve the corrosion resistance and mechanical properties of the brass strip, while achieving environmentally friendly and pollution-free production. Furthermore, a feedback optimization mechanism is introduced to continuously improve the production process based on actual usage and customer feedback, ensuring consistently high product quality and market competitiveness. This method not only solves the problem of dezincification corrosion that traditional brass materials are prone to in marine environments but also broadens its application scope in high-end manufacturing, marine engineering, and architectural hardware, bringing significant economic and social benefits.

[0074] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0075] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A method for preparing and testing corrosion-resistant brass strip, characterized in that, Includes the following steps: S1 Raw Material Procurement and Testing: After procuring raw materials such as copper, zinc, tin, aluminum, rare earth elements cerium and boron, the raw materials are screened after chemical composition analysis using a spectrometer. S2 Ingredients: Weigh the ingredients according to the chemical composition ratio, put them into the ingredient container, and mix them evenly; S3 Smelting and Casting: The prepared raw materials are added to the smelting furnace in batches. First, copper with a higher melting point is added, followed by zinc, tin, aluminum, boron and rare earth elements. The alloy liquid is stirred regularly. After smelting, the smelted alloy liquid is poured into the crystallizer of the continuous casting machine through a ladle for casting and then cut. S4 hot rolling: The ingot is first placed in a heating furnace for preheating, and then the heated ingot is placed in a hot rolling mill for multi-pass rolling. During the rolling process, cooling water is used to cool the rolls. S5 intermediate processing: The hot-rolled billet is put into a milling machine for milling to remove surface oxide scale and defects. Then the milled billet is put into a shearing machine for trimming to remove the edge parts. Finally, the trimmed billet is put into an annealing furnace for annealing. S6 Cold Rolling: The annealed billet is placed into a cold rolling mill and subjected to 6 passes of rough rolling, with the thinning amount controlled at about 15% per pass and the rolling speed at 1.5 m / s. The strip after rough rolling is then placed into a cold rolling mill and subjected to 4 passes of finish rolling, with the thinning amount controlled at about 8% per pass and the rolling speed at 2.0 m / s. The final rolled thickness is 0.3 mm. S7 Surface Treatment: The rolled strip is placed into the cleaning line for cleaning to remove surface oil and impurities. The temperature of the cleaning solution is controlled at about 55℃ and the cleaning time is 3 minutes. The cleaned strip is then placed into a chemical treatment tank for passivation treatment to form a dense oxide film. S8 performance testing: Randomly sample the finished strip, process the sample into a form suitable for testing, put it into a spectrometer for testing, and then put it into a universal testing machine and a salt spray test chamber for testing. S9 Finished Product Processing: The finished strip is placed into a tension leveling machine for tension leveling to eliminate residual stress and improve the flatness of the strip. The tension leveling force is controlled at 30kN and the tension leveling speed is 1.5m / min. The tension leveled strip is then placed into a cutting machine for cutting, and the cutting speed is controlled at 1.5m / min. S10 Packaging and Warehousing: The cut strips are placed into the packaging machine for roll packaging. Forklifts are used to move the packaged strips to the warehouse, where they are stored according to batch and specifications.

2. The method for preparing and testing corrosion-resistant brass strip according to claim 1, characterized in that: The percentage mass of the raw materials procured in step S1, raw material procurement and testing, is as follows: Copper (Cu): 65%; Zinc (Zn): 30%; Tin (Sn): 20%; Aluminum (Al): 10%; Rare earth element (cerium, Ce): 3%; Boron (B): 1%.

3. The method for preparing and testing corrosion-resistant brass strip according to claim 1, characterized in that: In step S3, during the melting and casting process, the medium-frequency induction melting furnace is gradually heated to 1100℃ and maintained at that temperature for 1.5 hours under argon protection with a flow rate of 0.5-1.0 L / min. In step S3, the continuous casting machine has a casting temperature of 1020℃, a casting speed of 0.8 m / min, and a cooling water temperature of 25℃.

4. The method for preparing and testing corrosion-resistant brass strip according to claim 1, characterized in that: In step S4, the heating furnace is heated to 920°C and maintained for 1.5 hours. In step S4, the hot rolling mill performs 4 passes of rolling, with a thinning amount of 25% per pass. The rolling temperature is controlled at 880°C and the rolling speed is 0.8 m / s.

5. The method for preparing and testing corrosion-resistant brass strip according to claim 1, characterized in that: During the intermediate processing in step S5, the milling depth is controlled at 1.5 mm and the milling speed at 0.8 m / min; the trimming width is controlled at 8 mm and the trimming speed at 0.8 m / min; the annealing furnace is used to gradually heat the material to 620°C and maintain the temperature for 1.5 hours.

6. The method for preparing and testing corrosion-resistant brass strip according to claim 1, characterized in that: In the surface treatment process of step S7, the passivation solution consists of 5% nitric acid, 3% phosphoric acid, and 2% chromic acid. The passivation time at room temperature is 8 minutes, and the passivation film thickness is 1.5 μm.

7. The method for preparing and testing corrosion-resistant brass strip according to claim 1, characterized in that: In the performance testing process of step S8, the universal testing machine tests the following: tensile strength 420MPa, elongation 35%, hardness 120HV, and salt spray test in a salt spray chamber, with the corrosion and oxidation area not exceeding 5% after 48 hours.

8. The method for preparing and testing corrosion-resistant brass strip according to claim 1, characterized in that: In step S10, the packaged strip is stored in the warehouse. When the packaged strip is stored in the warehouse, there should be a distance of at least 5 cm between two adjacent rolls of strip, and no more than 5 rolls should be stored on each layer. At the same time, the warehouse is equipped with an automatic temperature and humidity monitoring and control system, with the temperature controlled at 18-22℃ and the humidity controlled at 40-50%RH.

9. The method for preparing and testing corrosion-resistant brass strip according to claim 1, characterized in that: In step S3, during the melting and casting process, when the melting furnace is heated to 1100°C, the heating is paused and maintained at 800°C for 30 minutes to allow the raw materials in the furnace to be fully preheated and evenly heated. Then, the temperature is raised to 1100°C and maintained for 1.5 hours. Meanwhile, during the casting process on the continuous casting machine, when the ingot length reaches 80% of the set value, the casting speed is reduced to 0.6 m / min in advance and maintained for 1 minute before the cutting operation is performed.

10. The method for preparing and testing corrosion-resistant brass strip according to claim 1, characterized in that: In step S7, before passivation, an ultrasonic cleaning process is performed. The cleaned strip is placed in an ultrasonic cleaning tank and ultrasonic cleaning is performed using deionized water. The cleaning time is 5-10 minutes, the ultrasonic frequency is 28-40kHz, and the cleaning temperature is 40-50℃.

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