Civil air defense air-tight door integrated machining process

Abstract

The invention relates to the field of civil air defense door manufacturing, and particularly discloses an integrated machining process for a civil air defense airtight door. The integrated machining technology of the civil air-tight door comprises the steps that aluminum, magnesium and zinc are mixed and melted in proportion, then copper, manganese, chromium, titanium and silicon are added for refining, refined alloy liquid is cooled to obtain an alloy plate, the alloy plate is cut, then heated, extruded and formed, quenching is conducted, and the civil air-tight door is obtained. And the civil defense air-tight door is subjected to surface sand blasting, and then an anti-rust coating is sprayed. The civil air defense air-tight door integrated machining technology has the advantage that the anti-corrosion and anti-impact capacity of the civil air defense air-tight door is improved.

Description

Technical Field

[0001] The present application relates to the field of civil air defense door manufacturing, and more specifically, it relates to an integrated processing technology for civil air defense closed doors. Background Art

[0002] Civil air defense closed door, full name civil air defense closed door, is a special type of door, mainly used in the entrances and exits of various civil air defense projects, such as underground shopping malls, hospitals, warehouses, underground parking garages and other places that require a high level of protection. Its main functions include two aspects: one is to block shock waves, and the other is to effectively isolate the penetration of toxic agents to ensure the safety of the internal environment of civil air defense projects.

[0003] As a key element to ensure the safety of civil air defense projects, the quality of the processing technology of civil air defense closed doors is directly related to the structural strength and sealing performance of the door body. The traditional processing technology of civil air defense closed doors usually adopts a step-by-step processing and reassembly method. Although this process can meet production needs to a certain extent, its limitations are gradually revealed with the expansion of the market and higher requirements for product quality.

[0004] Step-by-step processing means that each process needs to be carried out separately, which not only increases the production cycle, but may also lead to waiting time and waste of resources in the production process. In addition, the raw materials used to make air-defense sealed doors are often only subjected to basic cutting, welding and other processing, without special anti-corrosion and anti-tensile processing. Due to the lack of a special anti-corrosion treatment process, the finished air-defense door is easily corroded in a humid and highly corrosive environment, resulting in surface rust, material performance degradation and other problems. Due to the lack of special anti-tensile processing, the finished air-defense door is prone to deformation or cracking when hit by external forces, reducing its impact resistance. Summary of the invention

[0005] In order to improve the anti-corrosion and impact resistance of civil air defense sealed doors, the present application provides an integrated processing technology for civil air defense sealed doors.

[0006] The integrated processing technology for air-raid-proof closed doors provided in this application adopts the following technical solutions: The integrated processing technology of civil air-defense closed doors includes the following steps: Mix 80-85 parts of aluminum, 5-8 parts of magnesium, and 4-6 parts of zinc in parts by weight in a heating furnace, heat to 720-760°C, melt them completely, and keep them warm for 30-50 minutes. Then add 1-2 parts of copper, 0.3-0.5 parts of manganese, and 0.1-0.3 parts of chromium to the heating furnace and mix them thoroughly. Add 0.05-0.15 parts of titanium and 0.1-0.3 parts of silicon into a heating furnace, and use argon gas for refining to remove impurities and bubbles, and pour the refined alloy liquid into a mold preheated to 300-350°C for cooling to obtain an alloy plate; Heat the alloy plate to 450-480℃ and keep it warm for 2-4 hours, and extrude the heated alloy plate in a hot pressing mold at 480-500℃ at a pressure of 200-400t to obtain a civil airtight door embryo, and after completion, quench the civil airtight door embryo to room temperature; The surface of the quenched airtight door blank body is polished and trimmed, and the gaps around the airtight door blank body are welded to obtain the airtight door; The welded air-defense closed door is sandblasted on the surface and then sprayed with anti-rust coating.

[0007] By adopting the above technical scheme, aluminum, magnesium and zinc are used as the main components, and trace elements such as copper, manganese, chromium, titanium and silicon are added. Through precise proportioning and high-temperature smelting, an alloy with excellent mechanical properties and corrosion resistance is formed. Based on the lightweight and high-strength characteristics of aluminum, the addition of magnesium improves the strength and toughness of the alloy, zinc enhances the corrosion resistance, and the addition of elements such as copper, manganese and chromium further refines the grains, improves the hardness and wear resistance of the alloy. The trace addition of titanium and silicon helps to improve the processing performance and refine the structure of the alloy and reduce defects. The alloy liquid is refined by argon gas, which effectively removes impurities and bubbles, improves the purity and density of the alloy, thereby reducing internal defects and enhancing the overall performance of the material. Suitable temperature and heat preservation, and then extrusion molding in a hot pressing mold by high tonnage pressure, this process not only reduces the deformation resistance of the alloy plate and makes it easy to form, but also further improves the strength and toughness of the material through recrystallization and phase change during the hot pressing process. The quenching treatment allows the material to cool rapidly, forming a stable organizational structure, improving the hardness and wear resistance of the material while maintaining good impact resistance. The surface sandblasting increases the adhesion of the coating, and the spraying of the anti-rust coating further improves the corrosion resistance and durability of the product, extending its service life.

[0008] Optionally, the anti-rust coating includes epoxy zinc-rich primer, mesh intermediate paint and aspartame polyurea topcoat.

[0009] By adopting the above technical solutions, the epoxy zinc-rich primer uses its high content of zinc powder as the main anti-rust component. The zinc powder forms a dense barrier in the coating, effectively isolating oxygen and moisture from direct contact with the substrate, thereby slowing down the corrosion process. Zinc powder can also undergo electrochemical reactions in a corrosive environment, sacrificing itself to protect the substrate, the so-called "cathodic protection" effect, which further enhances the anti-corrosion performance of the coating. The mesh intermediate paint serves as a bridge connecting the primer and the topcoat. Its mesh structure helps to increase the adhesion between the coatings and make the entire coating system more stable. Asparagus polyurea topcoat is known for its excellent wear resistance, chemical corrosion resistance and weather resistance. It can withstand high-intensity physical impact and chemical erosion, and maintain the gloss and color stability of the coating. The combination of epoxy zinc-rich primer, mesh intermediate paint and asparagus polyurea topcoat not only provides strong anti-corrosion protection, but also extends the service life of the product and reduces the cost of repair and replacement due to corrosion.

[0010] Optionally, the spraying method of the anti-rust coating is: first spray a layer of epoxy zinc-rich primer on the civil airtight door after sandblasting, the spraying thickness is 0.1-0.2mm, and then spray the mesh intermediate paint after the epoxy zinc-rich primer is completely dry, the spraying thickness is 0.2-0.4mm, and then spray the asparagus polyurea topcoat after the mesh intermediate paint is completely dry, the spraying thickness is 0.2-0.3mm.

[0011] By adopting the above technical solution, the coating performance is balanced by controlling the spraying thickness of each layer of coating. The thin coating of epoxy zinc-rich primer not only ensures sufficient anti-corrosion performance, but also avoids the problem of coating cracking caused by excessive thickness; the moderate thickness of the mesh intermediate paint provides good adhesion and air permeability; the thin and tough coating of the asparagus polyurea topcoat ensures the product's wear resistance and chemical corrosion resistance. The layered spraying method avoids cross-contamination and mutual interference between coatings, and improves construction efficiency and coating quality.

[0012] Optionally, the components of the mesh intermediate paint include, by weight, 50-70 parts of hydroxy acrylic resin, 10-30 parts of polyether polyol, 40-60 parts of polyisocyanate, 5-15 parts of γ-aminopropyltriethoxysilane, and 1-10 parts of nano zirconium oxide.

[0013] By adopting the above technical scheme, the hydroxy acrylic resin has good adhesion to the substrate, which can ensure the close combination between the coating and the substrate. At the same time, acrylic resin does not absorb ultraviolet rays and visible light above 300nm, so it has excellent weather resistance and can resist the erosion of natural environments such as sunlight, wind and rain for a long time. The ether bond in the polyether polyol is easier to rotate than the ester bond, so the glass transition temperature of the polyether is low, so that the paint film has excellent low-temperature flexibility. At the same time, there is no easily hydrolyzed ester group in the polyether, so the water resistance is better than that of polyester polyurethane, which helps the coating to maintain stable performance in a humid environment. And the polyether polyol has excellent alkaline hydrolysis resistance, can resist the erosion of alkaline substances, and protect the substrate from damage. Polyisocyanate reacts with the hydroxyl groups in the hydroxy acrylic resin and the polyether polyol to generate carbamate, forming a high molecular compound with a network structure. This cross-linked structure can significantly enhance the strength and hardness of the coating, and improve the wear resistance and impact resistance of the coating. The formation of the cross-linked structure makes the coating have a more compact structure, which can effectively block the penetration and erosion of chemical substances and improve the chemical resistance of the coating. As a coupling agent, γ-aminopropyltriethoxysilane can form a chemical bond between the coating and the substrate, significantly enhancing the adhesion of the coating. At the same time, it can also improve the water resistance and weather resistance of the coating and extend the service life of the coating. As an inorganic nanoparticle, nano zirconium oxide has excellent hardness and wear resistance. Adding it to the coating can significantly improve the wear resistance and corrosion resistance of the coating, making the coating more durable.

[0014] Optionally, the aspartame polyurea topcoat comprises, by weight, 60-70 parts of polyaspartic acid ester resin, 80-90 parts of isocyanate, 1-5 parts of organic bentonite, 5-10 parts of polynaphthalene sulfonate dispersant, and 1-5 parts of sulfonate wetting agent.

[0015] By adopting the above technical solution, polyaspartic acid ester resin as component A is combined with isocyanate curing agent as component B to form a high-performance aspartic polyurea coating. This coating has excellent weather resistance, chemical resistance and solvent resistance. Organic bentonite can form a gel in the coating, effectively increase the viscosity of the coating, prevent the coating from flowing or dripping during construction, and improve construction efficiency and quality. Organic bentonite can also improve the suspension stability and thixotropy of the coating, prevent the coating from settling and stratification, and ensure the uniformity and consistency of the coating. Sulfonate wetting agents can reduce the surface tension of the coating and improve the wettability and permeability of the coating to the substrate. This helps the coating to better adhere to the surface of the substrate and form a firm coating. Good wettability can also enhance the adhesion between the coating and the substrate, and improve the durability and service life of the coating.

[0016] Optionally, before the refining, 0.05-0.1 parts by weight of scandium needs to be added into the heating furnace.

[0017] By adopting the above technical solutions, the addition of scandium can significantly improve the strength, hardness and corrosion resistance of the alloy, so that it can maintain stable performance even in harsh environments. Scandium can refine the grains in the alloy and help form a more uniform and dense microstructure. This can not only improve the mechanical properties of the alloy, but also improve its processing performance and surface quality. And the addition of scandium can promote the phase change process, thereby optimizing the microstructure and properties of the alloy. The addition of scandium can also improve the fluidity of the alloy, making it easier to flow and mix evenly during the refining process. This helps to reduce casting defects and improve the yield of products.

[0018] Optionally, the cooling rate of the alloy liquid in the casting mold is 10-10 2 K / s.

[0019] By adopting the above technical solution, the above cooling rate helps to refine the grain structure of the casting. Fine grains can improve the strength and toughness of the casting, improve its comprehensive mechanical properties, and reduce the segregation of alloy elements during the solidification process, making the casting composition more uniform, thereby improving the consistency of its performance. The cooling rate of the present application helps to control the solidification sequence of the casting, reduce the generation of defects such as shrinkage cavities and shrinkage, and improve the density and internal quality of the casting.

[0020] Optionally, after the quenching is completed, the surface of the civil air defense door embryo body needs to be ground and polished, and then placed in a pure oxygen environment and heated to 500-550°C for 10-14 hours. After the treatment is completed, it is cooled to room temperature with the furnace.

[0021] By adopting the above technical solution, through heating treatment in a pure oxygen environment, the atoms and molecules inside the door body can be rearranged, thereby eliminating or reducing residual stress and further improving the strength and toughness of the door body.

[0022] In summary, this application has the following beneficial effects: 1. This application uses a precise ratio of main components such as aluminum, magnesium, zinc and trace elements such as copper, manganese, chromium, titanium, and silicon, and produces a high-performance alloy plate after high-temperature smelting and argon refining. Subsequently, the alloy plate is extruded into a human airtight door embryo through a hot pressing die, and is quenched to enhance hardness and wear resistance. Finally, the surface is sandblasted and treated with an anti-rust coating to significantly improve the corrosion resistance and durability of the product, ensuring that the human airtight door is both durable and has excellent protective performance.

[0023] 2. In this application, the epoxy zinc-rich primer is preferably used to construct a dense barrier through high zinc powder content, combined with the cathodic protection of zinc powder, effectively isolate corrosion factors and significantly enhance corrosion resistance. The mesh intermediate paint strengthens the adhesion between coatings and stabilizes the overall system. The asparagus polyurea topcoat provides long-term protection for the coating system with its excellent wear resistance, chemical corrosion resistance and weather resistance. The combination of the three not only builds a strong anti-corrosion barrier, but also significantly extends the service life of the product and reduces maintenance costs.

[0024] 3. In this application, it is preferred that before refining in a heating furnace, an additional 0.05-0.1 parts of scandium be added, which can significantly improve the strength, hardness and corrosion resistance of the alloy, refine the grains, optimize the microstructure, improve the processing performance and surface quality, and promote the phase change process to enhance the alloy performance. At the same time, the cooling rate of the alloy liquid in the mold is controlled within the range of 10-102K / s, which helps to refine the grains, improve the strength and toughness of the casting, reduce component segregation, improve performance consistency, and reduce casting defects, ensuring the high density and internal quality of the casting. DETAILED DESCRIPTION

[0025] The present application is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the experiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0026] Preparation example of mesh intermediate paint Preparation Example 1 Prepare 60kg of Caforme CFU2460B hydroxy acrylic resin, 20kg of 99% pure polyether polyol from Hubei Junrui Biotechnology Co., Ltd., 50kg of DIC BURNOCK DNW-5500 polyisocyanate, 10kg of KH-550γ-aminopropyl triethoxysilane, and 5kg of 99.99% pure nano zirconium oxide; Add hydroxy acrylic resin and polyether polyol into the reactor, stir and mix at 90°C for 30 minutes to make them fully mixed. Slowly add polyisocyanate while stirring. Continue stirring and reacting at 90°C for 1 hour and then cool to 30°C. Add γ-aminopropyl triethoxysilane into the reactor and stir for 30 minutes, slowly add nano zirconium oxide into the reactor, continue stirring for 2 hours to obtain a mesh intermediate paint.

[0027] Preparation Example 2 The difference from Preparation Example 1 is that no nano zirconium oxide is added.

[0028] Preparation Example of Aspartame Polyurea Topcoat Preparation Example 3 Preparation of an asparagus polyurea topcoat: Prepare 65kg of polyaspartic acid resin with a solid content of 96±2%, 85kg of isocyanate, 3kg of organic bentonite with a purity of 99%, 8kg of Nopco SN-5040 polynaphthalenesulfonate dispersant, and 3kg of sodium succinate octyl sulfonate; Mix the organic bentonite with the dispersant, add 10 kg of acetone, stir evenly, add the polyaspartic acid ester resin and sodium succinate sulfonate wetting agent into the reactor, stir at room temperature for 30 minutes to ensure that the wetting agent is fully mixed in the resin, slowly add the pre-dispersed organic bentonite mixture into the mixture of the resin and the wetting agent, add isocyanate while stirring, continue stirring and reacting at room temperature for 2 hours, and after the reaction is completed, vacuum degassing is performed to obtain the aspartame polyurea topcoat.

[0029] Preparation Example 4 Preparation of an asparagus polyurea topcoat: The difference from Preparation Example 3 is that no organic bentonite is added. Example

[0030] Example 1 Integrated processing technology of air-defense closed doors: The required metal raw materials are weighed: 83kg aluminum, 6kg magnesium, and 5kg zinc. These raw materials are carefully mixed and placed in a dedicated heating furnace. The heating furnace is set at 750°C to ensure that all metal raw materials can be completely melted and mixed evenly. During the melting process, continuous stirring is required to ensure the uniformity of the molten metal, and the temperature is kept for 40 minutes to allow the molten metal to reach a stable molten state.

[0031] Then, add 1.2kg of copper, 0.4kg of manganese and 0.2kg of chromium to the molten metal. During the addition process, pour slowly and evenly, and use a stirring tool to ensure that the alloy elements are evenly distributed in the molten metal.

[0032] Next, 0.12kg of titanium and 0.2kg of silicon are added to the alloy liquid, and then argon gas is used for refining, and impurities and bubbles in the metal liquid are removed by the flow of argon gas. After the refining is completed, the refined alloy liquid is slowly and steadily poured into a mold preheated to 320°C, and it is cooled and solidified at a cooling rate of 50K / s to form an alloy plate.

[0033] The cooled alloy plate is heated again to 460°C and kept at this temperature for 3 hours to eliminate internal stress and optimize the microstructure. Subsequently, the heated alloy plate is placed in a hot pressing mold at 500°C and extruded under a pressure of up to 300 tons to form a human-airtight door embryo with a specific shape and size. After forming, the embryo is immediately quenched and quickly cooled to room temperature to fix its shape and performance.

[0034] After quenching, the airtight door blank needs to be finely polished and trimmed. At the same time, the gaps around the blank need to be precisely welded to ensure the sealing and structural strength of the door. After welding, the welds need to be inspected and trimmed.

[0035] Finally, the welded air-defense closed door is subjected to surface sandblasting treatment to remove the oxide scale and impurities on the surface and improve the adhesion of the coating. A layer of epoxy zinc-rich primer is first sprayed on the air-defense closed door after sandblasting treatment, with a spraying thickness of 0.2 mm. After the epoxy zinc-rich primer is completely dried, a mesh intermediate paint is sprayed with a spraying thickness of 0.3 mm. After the mesh intermediate paint is completely dried, an asparagus polyurea topcoat is sprayed with a spraying thickness of 0.3 mm. The epoxy zinc-rich primer adopts 70% zinc content of Yubang coating, the mesh intermediate paint is prepared by Preparation Example 1, and the asparagus polyurea topcoat is prepared by Preparation Example 3.

[0036] Example 2 The integrated processing technology of air-defense closed doors is different from that of Example 1 in that the required metal raw materials are weighed: 80 kg of aluminum, 5 kg of magnesium, and 4 kg of zinc. These raw materials are carefully mixed and placed in a dedicated heating furnace. The heating furnace is set at 750°C to ensure that all metal raw materials can be completely melted and mixed evenly. During the melting process, continuous stirring is required to ensure the uniformity of the molten metal, and the heat is kept for 40 minutes to allow the molten metal to reach a stable molten state.

[0037] Then, add 1kg of copper, 0.3kg of manganese and 0.1kg of chromium to the molten metal. During the addition process, pour slowly and evenly, and use a stirring tool to ensure that the alloy elements are evenly distributed in the molten metal.

[0038] Next, 0.05kg of titanium and 0.1kg of silicon are added to the alloy liquid, and then argon gas is used for refining, and impurities and bubbles in the metal liquid are removed by the flow of argon gas. After the refining is completed, the refined alloy liquid is slowly and steadily poured into a mold preheated to 320°C, and it is cooled and solidified at a cooling rate of 50K / s to form an alloy plate.

[0039] Example 3 The integrated processing technology of airtight doors for civil defense is different from that of Example 1 in that the required metal raw materials are weighed: 85 kg of aluminum, 8 kg of magnesium, and 6 kg of zinc. These raw materials are carefully mixed and placed in a dedicated heating furnace. The heating furnace is set at 750°C to ensure that all metal raw materials can be completely melted and mixed evenly. During the melting process, continuous stirring is required to ensure the uniformity of the molten metal, and the heat is kept for 40 minutes to allow the molten metal to reach a stable molten state.

[0040] Then, add 2kg of copper, 0.5kg of manganese and 0.3kg of chromium to the molten metal. During the addition process, pour slowly and evenly, and use a stirring tool to ensure that the alloy elements are evenly distributed in the molten metal.

[0041] Next, 0.15kg of titanium and 0.3kg of silicon are added to the alloy liquid, and then argon gas is used for refining, and impurities and bubbles in the metal liquid are removed by the flow of argon gas. After the refining is completed, the refined alloy liquid is slowly and steadily poured into a mold preheated to 320°C, and it is cooled and solidified at a cooling rate of 50K / s to form an alloy plate.

[0042] Example 4 The integrated processing technology of civil airtight doors is different from that of Example 1 in that 0.05 kg of scandium needs to be added into the heating furnace before refining.

[0043] Example 5 The integrated processing technology of civil airtight doors is different from that of Example 1 in that 0.07 kg of scandium needs to be added into the heating furnace before refining.

[0044] Example 6 The integrated processing technology of civil airtight doors is different from that of Example 1 in that 0.1 kg of scandium needs to be added into the heating furnace before refining.

[0045] Example 7 The integrated processing technology of civil air defense closed doors is different from that of Example 1 in that: after quenching, the surface of the civil air defense door blank needs to be ground and polished, then placed in a pure oxygen environment and heated to 530°C for 12 hours, and then cooled to room temperature with the furnace after the treatment is completed.

[0046] Comparative Example Comparative Example 1 The integrated processing technology of civil airtight doors is different from that of Example 1 in that the mesh intermediate paint is prepared by Preparation Example 2.

[0047] Comparative Example 2 The integrated processing technology of civil air-defense closed doors is different from that of Example 1 in that the asparagine polyurea topcoat is prepared by Preparation Example 4.

[0048] Comparative Example 3 The integrated processing technology of air-raid-proof closed doors is different from that of Example 1 in that the cooling rate of the alloy liquid in the casting mold is 10 3 K / s.

[0049] Comparative Example 4 The integrated processing technology of civil air-defense closed doors is different from that of Example 1 in that mesh intermediate paint is not sprayed.

[0050] Comparative Example 5 Integrated processing technology of air-defense closed doors: The required metal raw materials are weighed: 83kg aluminum, 6kg magnesium, and 5kg zinc. These raw materials are carefully mixed and placed in a dedicated heating furnace. The heating furnace is set at 750°C to ensure that all metal raw materials can be completely melted and mixed evenly. During the melting process, continuous stirring is required to ensure the uniformity of the molten metal, and the temperature is kept for 40 minutes to allow the molten metal to reach a stable molten state.

[0051] Then, add 1.2kg of copper, 0.4kg of manganese and 0.2kg of chromium to the molten metal. During the addition process, pour slowly and evenly, and use a stirring tool to ensure that the alloy elements are evenly distributed in the molten metal.

[0052] Next, 0.12kg of titanium and 0.2kg of silicon are added to the alloy liquid, and then argon gas is used for refining, and impurities and bubbles in the metal liquid are removed by the flow of argon gas. After the refining is completed, the refined alloy liquid is slowly and steadily poured into a mold preheated to 320°C, and it is cooled and solidified at a cooling rate of 50K / s to form an alloy plate.

[0053] The cooled alloy plate is cut according to the predetermined design size. The cut alloy plate is heated to 460℃ again and kept at this temperature for 3 hours to eliminate internal stress and optimize the microstructure. Subsequently, the cut alloy plate is finely surface polished and trimmed, and then the sheet alloy plate is spliced ​​and welded to obtain the airtight door. After welding, the weld is inspected and trimmed.

[0054] Finally, the welded air-defense closed door is subjected to surface sandblasting treatment to remove the oxide scale and impurities on the surface and improve the adhesion of the coating. A layer of epoxy zinc-rich primer is first sprayed on the air-defense closed door after sandblasting treatment, with a spraying thickness of 0.2 mm. After the epoxy zinc-rich primer is completely dried, a mesh intermediate paint is sprayed with a spraying thickness of 0.3 mm. After the mesh intermediate paint is completely dried, an asparagus polyurea topcoat is sprayed with a spraying thickness of 0.3 mm. The epoxy zinc-rich primer adopts 70% zinc content of Yubang coating, the mesh intermediate paint is prepared by Preparation Example 1, and the asparagus polyurea topcoat is prepared by Preparation Example 3.

[0055] Performance testing Detection Methods According to the standards of ISO 6892 and ISO 148, the airtight doors prepared in Examples 1-7 and Comparative Example 3 were subjected to strength and -40°C impact tests.

[0056] According to ISO 9227: Corrosion test-Salt spray test, a corrosion test was performed on Example 1 and Comparative Examples 1, 2 and 4.

[0057] Table 1 Mechanical properties test Table 2 Corrosion resistance test It can be seen from Example 1 and Comparative Example 3 and Table 1 that the cooling rate of the present application helps to control the solidification sequence of the casting, reduce the occurrence of defects such as shrinkage cavities and shrinkage porosity, improve the strength and toughness of the casting, and improve its comprehensive mechanical properties.

[0058] It can be seen from Example 1 and Comparative Examples 1, 2, and 4 and Table 2 that the mesh intermediate paint serves as a bridge connecting the primer and the topcoat, and the polyisocyanate reacts with the hydroxyl groups in the hydroxy acrylic resin and the polyether polyol to generate carbamate, forming a high molecular compound with a mesh structure. This cross-linked structure can significantly enhance the strength and hardness of the coating, and improve the wear resistance and impact resistance of the coating. The formation of the cross-linked structure makes the coating have a more compact structure, which can effectively block the penetration and erosion of chemical substances, and improve the chemical resistance of the coating. Nano zirconium oxide, as an inorganic nanoparticle, has excellent hardness and wear resistance. Adding it to the coating can significantly improve the wear resistance and corrosion resistance of the coating, making the coating more durable. Polyaspartic acid ester resin as component A is combined with component B isocyanate curing agent to form a high-performance aspartic polyurea coating. This coating has excellent weather resistance, chemical resistance and solvent resistance. Organic bentonite can form a gel in the coating, effectively increase the viscosity of the coating, prevent the coating from flowing or dripping during construction, and improve construction efficiency and quality. Organic bentonite can also improve the suspension stability and thixotropy of the coating, prevent the coating from settling and stratification, and ensure the uniformity and consistency of the coating.

[0059] It can be seen from Example 1 and Comparative Example 5 and Table 1 that compared with conventional cutting, assembly and welding methods, the civil air defense door obtained by one-piece molding using a hot pressing mold in the present application has higher mechanical properties.

[0060] It can be seen from Examples 1-3 and Table 1 that by adjusting the alloy components, the mechanical properties of the alloy can be further improved so that the manufactured civil air defense door can achieve higher impact resistance.

[0061] It can be seen from Example 1 and Examples 4-6 and Table 1 that the addition of scandium can significantly improve the strength, hardness and corrosion resistance of the alloy, so that it can maintain stable performance even in harsh environments. Scandium can refine the grains in the alloy and help form a more uniform and dense microstructure. This can not only improve the mechanical properties of the alloy, but also improve its processing performance and surface quality. Through heating treatment in a pure oxygen environment, the atoms and molecules inside the door body can be rearranged, thereby eliminating or reducing residual stress and further improving the strength and toughness of the door body.

[0062] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. The integrated processing technology of air-defense closed doors is characterized by: The following steps are involved: Mix 80-85 parts of aluminum, 5-8 parts of magnesium, and 4-6 parts of zinc in parts by weight in a heating furnace, heat to 720-760°C, melt them completely, and keep them warm for 30-50 minutes. Then add 1-2 parts of copper, 0.3-0.5 parts of manganese, and 0.1-0.3 parts of chromium to the heating furnace and mix them thoroughly. Add 0.05-0.15 parts of titanium and 0.1-0.3 parts of silicon into a heating furnace, and use argon gas for refining to remove impurities and bubbles, and pour the refined alloy liquid into a mold preheated to 300-350°C for cooling to obtain an alloy plate; Heat the alloy plate to 450-480℃ and keep it warm for 2-4 hours, and extrude the heated alloy plate in a hot pressing mold at 480-500℃ at a pressure of 200-400t to obtain a civil airtight door embryo, and after completion, quench the civil airtight door embryo to room temperature; The surface of the quenched airtight door blank body is polished and trimmed, and the gaps around the airtight door blank body are welded to obtain the airtight door; The welded air-defense closed door is sandblasted on the surface and then sprayed with anti-rust coating.

2. The integrated processing technology for civil air-raid sealed doors according to claim 1 is characterized in that: The anti-rust coating comprises an epoxy zinc-rich primer, a mesh intermediate paint and an aspartame polyurea topcoat.

3. The integrated processing technology for civil air-raid sealed doors according to claim 2 is characterized in that: The spraying method of the anti-rust coating is: first spray a layer of epoxy zinc-rich primer on the sandblasted civil airtight door, the spraying thickness is 0.1-0.2mm, and then spray the mesh intermediate paint after the epoxy zinc-rich primer is completely dry, the spraying thickness is 0.2-0.4mm, and then spray the asparagus polyurea topcoat after the mesh intermediate paint is completely dry, the spraying thickness is 0.2-0.3mm.

4. The integrated processing technology for civil air-raid sealed doors according to claim 2 is characterized in that: The components of the mesh intermediate paint include, by weight, 50-70 parts of hydroxy acrylic resin, 10-30 parts of polyether polyol, 40-60 parts of polyisocyanate, 5-15 parts of gamma-aminopropyltriethoxysilane, and 1-10 parts of nano zirconium oxide.

5. The integrated processing technology for civil air-raid sealed doors according to claim 2 is characterized in that: The aspartame polyurea topcoat comprises, by weight, 60-70 parts of polyaspartic acid ester resin, 80-90 parts of isocyanate, 1-5 parts of organic bentonite, 5-10 parts of polynaphthalene sulfonate dispersant, and 1-5 parts of sulfonate wetting agent.

6. The integrated processing technology for civil air-raid sealed doors according to claim 1 is characterized in that: Before the refining, 0.05-0.1 parts by weight of scandium need to be added into the heating furnace.

7. The integrated processing technology for civil air-raid sealed doors according to claim 1 is characterized in that: The cooling rate of the alloy liquid in the casting mold is 10-10 2 K / s.

8. The integrated processing technology for civil air-raid sealed doors according to claim 1 is characterized in that: After the quenching is completed, the surface of the civil air defense door blank needs to be ground and polished, and then placed in a pure oxygen environment and heated to 500-550°C for 10-14 hours. After the treatment is completed, it is cooled to room temperature with the furnace.

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