Degradable environment-friendly welding auxiliary material for ocean engineering

Abstract

The invention discloses a degradable environment-friendly welding auxiliary material for ocean engineering. The degradable environment-friendly welding auxiliary material is prepared from, by weight, 30-50 parts of natural degradable polymer, 8-12 parts of plasticizer, 12-18 parts of fluxing agent, 10-15 parts of binder, 4-7 parts of antioxidant, 2-4 parts of defoaming agent, 3-6 parts of metal ion source, 2-5 parts of bioactive additive and 1-3 parts of ultraviolet light absorber. The invention has the beneficial effects of degradability, low toxicity and safety, good molten pool performance, enhanced adhesiveness and stability, improved material stability, promotion of sustainable development and reduction of long-term cost.

Description

Technical Field

[0001] The invention relates to the field of welding auxiliary materials, and in particular to a degradable and environment-friendly welding auxiliary material for marine engineering. Background Art

[0002] Marine engineering covers many fields, including but not limited to the construction and maintenance of offshore platforms, laying of submarine pipelines, manufacturing and repair of ships, and construction of coastal protection facilities. In the implementation of these projects, welding is a vital connection process and a key means to ensure structural strength and sealing. However, the welding auxiliary materials widely used in marine engineering are mainly based on traditional chemical synthetic materials. Although these materials can meet the basic needs of welding to a certain extent, they bring serious environmental problems.

[0003] Traditional welding auxiliary materials generally include welding flux, welding slag cleaner, anti-spatter agent, shielding gas and other types. In the welding process, welding flux, as an important auxiliary material, helps to remove oxides and impurities on the metal surface, promote the formation of the molten pool and the fusion between metals. However, commonly used welding fluxes often contain a large amount of chemical substances, such as fluorides, chlorides and other ingredients. These substances will produce irritating and toxic fumes during welding, which not only poses a threat to the health of operators, but also in the marine environment, these fumes will spread with the flow of sea breeze and seawater, causing direct or indirect damage to the surrounding marine life and ecosystems.

[0004] Weld slag cleaners are used to remove residual welding slag after welding. They are usually strong alkaline or acidic substances. Their residues will change the pH of seawater after entering the ocean, causing great damage to the living environment of marine life. Marine life is extremely sensitive to changes in pH. Even a small change in pH may cause physiological dysfunction of marine life, affecting their reproduction, growth and survival, and thus destroying the balance of the entire marine ecology. Moreover, the chemicals in these cleaners may remain in the marine environment for a long time and are difficult to decompose naturally. As time accumulates, they will form a pollutant sediment layer on the seabed, which will have a lasting negative impact on the benthic community on the seabed.

[0005] The use of anti-splash agents is to prevent metal splashes generated during welding from adhering to welding equipment and workpiece surfaces, but most of them contain organic solvents and surfactants. Organic solvents will evaporate into the marine atmosphere or dissolve in seawater, polluting the marine atmosphere and seawater. On the one hand, these organic solvents will affect the respiration and metabolic processes of marine organisms and have toxic effects on the cell membranes, proteins and enzyme systems of marine organisms; on the other hand, the long-term presence of organic solvents in the ocean will affect the optical properties and chemical balance of seawater, interfere with the penetration of light and photosynthesis in the ocean, and interfere with the energy flow and material circulation of the entire marine ecosystem.

[0006] At the same time, for shielding gases, although some gases themselves are relatively harmless, during storage and use, the containers and auxiliary devices used may release harmful substances due to corrosion or leakage. Once these substances enter the ocean, they will have irreversible effects on the marine environment. In addition, the packaging materials of traditional welding auxiliary materials are mostly difficult to degrade plastic products. Once these packaging wastes enter the ocean, they will float on the sea surface or sink to the bottom of the sea, and may be accidentally eaten by marine organisms, causing blockage of the digestive tract of marine organisms and even death.

[0007] From the overall scale of marine engineering, with the increasing development and utilization of marine resources around the world, the number and scale of marine engineering projects are expanding, the amount of welding auxiliary materials used is also increasing significantly, and the resulting environmental problems are becoming increasingly prominent. These problems not only pose a serious threat to marine biodiversity and ecological balance, but may also ultimately affect human health and sustainable development through the food chain.

[0008] In view of the above situation, it is urgent to develop a new type of welding auxiliary material that can meet the various welding process requirements in marine engineering, has good degradability and environmental protection performance, and can minimize the impact on the marine environment. This will not only help to achieve the sustainable development of marine engineering, but also is an important measure for humans to protect the marine ecosystem and fulfill their environmental protection responsibilities while developing and utilizing marine resources. It has far-reaching significance for maintaining the balance of marine ecology and the long-term interests of mankind. Summary of the invention

[0009] In order to solve the above problems, especially to address the deficiencies in the prior art, the present invention provides a degradable and environmentally friendly welding auxiliary material for marine engineering that can solve the above problems.

[0010] To achieve the above purpose, the present invention adopts the following technical means:

[0011] A degradable and environment-friendly welding auxiliary material for marine engineering is composed of the following raw materials in parts by weight: 30-50 parts of natural degradable polymer, 8-12 parts of plasticizer, 12-18 parts of flux, 10-15 parts of binder, 4-7 parts of antioxidant, 2-4 parts of defoamer, 3-6 parts of metal ion source, 2-5 parts of bioactive additive and 1-3 parts of ultraviolet absorber.

[0012] A further embodiment of the present invention is that the natural degradable polymer is sodium alginate, chitosan, cellulose or a combination thereof.

[0013] A further embodiment of the present invention is that the plasticizer is tributyl citrate, glycerol or polyethylene glycol.

[0014] A further embodiment of the present invention is that the flux is borax, potassium fluoride, sodium fluoride, zinc chloride or a combination thereof.

[0015] A further embodiment of the present invention is that the binder is starch, dextrin or gum arabic.

[0016] A further embodiment of the present invention is that the antioxidant is vitamin C, tocopherol or propyl gallate.

[0017] A further embodiment of the present invention is that the defoaming agent is polydimethylsiloxane.

[0018] A further embodiment of the present invention is that the metal ion source is calcium nitrate, magnesium sulfate or ferrous sulfate.

[0019] A further embodiment of the present invention is that the bioactive additive is chitosan oligosaccharide, microbial preparation or marine biological extract; and the ultraviolet absorber is hydroxybenzotriazole or benzophenone compound.

[0020] A further embodiment of the present invention is that the preparation method comprises the following steps:

[0021] The first step: weigh each raw material by weight;

[0022] Step 2: Add the natural degradable polymer into an appropriate amount of water and stir evenly to form a solution or dispersion;

[0023] Step 3: Add plasticizer, flux, binder, antioxidant, defoamer, metal ion source, bioactive additive and ultraviolet absorber in sequence and stir evenly;

[0024] Step 4: Form the mixture into the desired shape through a molding process;

[0025] Step 5: Dry the molding material to make its moisture content less than 5%, and finally obtain a degradable and environmentally friendly welding auxiliary material for marine engineering.

[0026] Beneficial effects of the present invention:

[0027] 1. The present invention is biodegradable. The present invention mainly uses natural biodegradable polymers (such as sodium alginate, chitosan, cellulose or a combination thereof) as the main components, which can be effectively decomposed by microorganisms in the marine environment. For example, sodium alginate can be gradually hydrolyzed into small molecule sugars under the enzymatic action of marine microorganisms, and finally converted into carbon dioxide, water and other harmless organic compounds; chitosan will be decomposed into simple sugars, amino acids and carbon dioxide by microorganisms in the marine environment, and will not remain for a long time like traditional welding auxiliary materials, thus avoiding long-term accumulation and pollution to the marine environment.

[0028] The degradation process of the entire auxiliary material is relatively thorough and will not produce difficult-to-degrade solid waste. It can significantly reduce the long-term pressure on the marine ecosystem, protect the habitat of marine organisms, and maintain the ecological balance of the ocean.

[0029] 2. The present invention has low toxicity and safety. Compared with traditional welding auxiliary materials, the components used in the present invention, such as plasticizers (tributyl citrate, glycerol, polyethylene glycol), binders (starch, dextrin, gum arabic), antioxidants (vitamin C, tocopherol, propyl gallate), etc., have low toxicity or no toxicity. Even if a small amount of these components enter the marine environment during use, they will not cause harm to marine organisms and will not interfere with the physiological processes of marine organisms, such as growth, reproduction, respiration and metabolism.

[0030] The defoaming agent (polydimethylsiloxane) and UV absorber (hydroxybenzotriazole, benzophenone compounds) in the material have also been carefully selected. They have good stability and biocompatibility in the marine environment, will not cause adverse effects on marine life and seawater properties, and reduce the risk of chemical pollution to the marine environment.

[0031] 3. The present invention has good molten pool performance. The addition of flux (borax, potassium fluoride, sodium fluoride, zinc chloride or a combination thereof) helps to reduce the viscosity of the slag during welding and improve the fluidity and wettability of the molten pool. During welding, the metals in the molten pool can be better fused to form a more uniform and dense weld, thereby improving the welding quality, enhancing the strength and sealing of the welded joint, and ensuring the reliability and safety of the marine engineering structure.

[0032] At the same time, the optimization of slag viscosity can reduce welding defects, such as the formation of pores and slag inclusions. For welding structures with higher requirements in marine engineering, such as key supporting structures of offshore platforms and connection parts of submarine pipelines, it can significantly improve the welding success rate and the durability of welds.

[0033] 4. The present invention enhances adhesion and stability. The binder (starch, dextrin, gum arabic) can make the auxiliary material firmly adhere to the welding part, avoid falling off due to the stirring of the molten pool, metal splashing or seawater scouring during the welding process, and ensure that the auxiliary material continues to play a role in the entire welding process.

[0034] This not only improves the convenience of welding operation and reduces the waste of auxiliary materials, but also can provide stable protection for the welding area, such as preventing the welding area from oxidation at high temperatures, and helps to form a weld with good appearance and reliable quality.

[0035] 5. The present invention improves the stability of materials. Antioxidants can prevent auxiliary materials from deteriorating due to oxidation during storage and use, ensuring that the performance of the materials remains stable for a long time. This is very important for welding operations in long-term storage and harsh marine environment conditions that may be encountered in marine engineering, avoiding the impact of material performance degradation on welding quality.

[0036] UV absorbers can protect materials from the effects of ultraviolet rays in the marine environment. For welding operations exposed on the sea surface or in shallow sea areas, they can prevent the aging and performance degradation of auxiliary materials, ensure the stable performance of materials throughout their entire use cycle, and extend the effective use time of auxiliary materials.

[0037] 6. The present invention can promote sustainable development. With the continuous expansion of the scale of marine engineering, the use of the degradable and environmentally friendly welding auxiliary material of the present invention can protect the marine environment while meeting the needs of engineering construction, and promote the coordinated development of marine resource development and utilization and environmental protection.

[0038] It helps to enhance the environmental image of marine engineering projects, meets the requirements of today's society for green environmental protection and sustainable development, provides more environmentally friendly technical support and material selection for future marine engineering projects, and promotes the entire marine engineering industry to develop in a more environmentally friendly and sustainable direction.

[0039] 7. The present invention can reduce long-term costs. Since the material is degradable, the cost of cleaning and handling the residue after welding is reduced, and the environmental governance costs caused by the pollution of traditional welding auxiliary materials are avoided. At the same time, its good welding performance can reduce the rework and maintenance costs caused by welding quality problems, which helps to reduce the overall cost of marine engineering in the long run. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is described clearly and completely below. 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 creative work are within the scope of protection of the present invention.

[0041] Example 1

[0042] A method for preparing a degradable and environmentally friendly welding auxiliary material for marine engineering comprises the following steps:

[0043] First, accurately weigh the raw materials according to the following weight: 30 parts of natural degradable polymer, 8 parts of plasticizer, 12 parts of flux, 10 parts of binder, 4 parts of antioxidant, 2 parts of defoamer, 3 parts of metal ion source, 2 parts of bioactive additive, 1 part of ultraviolet absorber. During the weighing process, a high-precision balance or weighing equipment is required to ensure the accuracy of the weight of each component, which is an important prerequisite for ensuring the stable performance of the final product.

[0044] The natural degradable polymer is added to an appropriate amount of water to form a preliminary solution or dispersion system. In the specific operation, it is added to water at a temperature of 50° C. and stirred at a speed of 300 rpm.

[0045] Next, plasticizer, flux, binder, antioxidant, defoamer, metal ion source, bioactive additive and ultraviolet absorber are added in a predetermined order. When adding each component, the stirring speed can be increased to 400 rpm, and stirring needs to be continued for 10 minutes after each addition to ensure that the component is fully dispersed and mixed evenly.

[0046] After that, the resulting mixture is formed into the desired shape through molding processes such as extrusion, injection molding, pressing or casting. During extrusion molding, a single-screw or twin-screw extruder can be used, and the appropriate mold can be selected according to the desired product shape. The temperature, pressure and screw speed of the extruder can be controlled to ensure the quality of product molding; during injection molding, the injection molding pressure, temperature and holding time and other parameters need to be accurately controlled to ensure that the material can completely fill the mold cavity and form a product with complete shape and precise size; during the pressing process, the pressing pressure and time should be reasonably adjusted according to the shape and thickness of the product to ensure uniform product density; during casting molding, the height and speed of the scraper should be controlled to spread the material evenly and form a film or sheet with uniform thickness.

[0047] Finally, the formed material is dried. Drying can be done in an oven with the temperature set at 60°C. During the drying process, the material should be turned over or ventilated regularly to ensure that the moisture can evaporate evenly until the moisture content is less than 5%. During the drying process, the moisture content of the product needs to be monitored. A moisture tester or drying method can be used to test the product to ensure that the degree of dryness meets the requirements. The entire drying process may take several hours to dozens of hours, and finally a degradable and environmentally friendly welding auxiliary material for marine engineering is obtained.

[0048] Example 2

[0049] A method for preparing a degradable and environmentally friendly welding auxiliary material for marine engineering comprises the following steps:

[0050] First, weigh the raw materials accurately according to the following weight parts: 40 parts of natural degradable polymer, 10 parts of plasticizer, 16 parts of flux, 12 parts of binder, 6 parts of antioxidant, 3 parts of defoamer, 5 parts of metal ion source, 3 parts of bioactive additive, 2 parts of ultraviolet absorber. During the weighing process, a high-precision balance or weighing equipment is required to ensure the accuracy of the weight of each component, which is an important prerequisite for ensuring the stable performance of the final product.

[0051] The natural degradable polymer is added to an appropriate amount of water to form a preliminary solution or dispersion system. In the specific operation, it is added to water at a temperature of 60° C. and stirred at a speed of 400 rpm.

[0052] Next, plasticizer, flux, binder, antioxidant, defoamer, metal ion source, bioactive additive and ultraviolet absorber are added in a predetermined order. When adding each component, the stirring speed can be increased to 500 rpm, and stirring should be continued for 15 minutes after each addition to ensure that the component is fully dispersed and mixed evenly.

[0053] After that, the resulting mixture is formed into the desired shape through molding processes such as extrusion, injection molding, pressing or casting. During extrusion molding, a single-screw or twin-screw extruder can be used, and the appropriate mold can be selected according to the desired product shape. The temperature, pressure and screw speed of the extruder can be controlled to ensure the quality of product molding; during injection molding, the injection molding pressure, temperature and holding time and other parameters need to be accurately controlled to ensure that the material can completely fill the mold cavity and form a product with complete shape and precise size; during the pressing process, the pressing pressure and time should be reasonably adjusted according to the shape and thickness of the product to ensure uniform product density; during casting molding, the height and speed of the scraper should be controlled to spread the material evenly and form a film or sheet with uniform thickness.

[0054] Finally, the formed material is dried. Drying can be done in an oven with the temperature set at 80°C. During the drying process, the material should be turned over or ventilated regularly to ensure that the moisture can evaporate evenly until the moisture content is less than 5%. During the drying process, the moisture content of the product needs to be monitored. A moisture tester or drying method can be used to test the product to ensure that the degree of dryness meets the requirements. The entire drying process may take several hours to dozens of hours, and finally a degradable and environmentally friendly welding auxiliary material for marine engineering is obtained.

[0055] Example 3

[0056] A method for preparing a degradable and environmentally friendly welding auxiliary material for marine engineering comprises the following steps:

[0057] First, weigh the raw materials accurately according to the following weight parts: 50 parts of natural degradable polymer, 12 parts of plasticizer, 18 parts of flux, 15 parts of binder, 7 parts of antioxidant, 4 parts of defoamer, 6 parts of metal ion source, 5 parts of bioactive additive, 3 parts of ultraviolet absorber. During the weighing process, a high-precision balance or weighing equipment is required to ensure the accuracy of the weight of each component, which is an important prerequisite for ensuring the stable performance of the final product.

[0058] The natural degradable polymer is added to an appropriate amount of water to form a preliminary solution or dispersion system. In the specific operation, it is added to water at a temperature of 70° C. and stirred at a speed of 500 rpm.

[0059] Next, plasticizer, flux, binder, antioxidant, defoamer, metal ion source, bioactive additive and ultraviolet absorber are added in a predetermined order. When adding each component, the stirring speed can be increased to 600 rpm, and stirring needs to be continued for 20 minutes after each addition to ensure that the component is fully dispersed and mixed evenly.

[0060] After that, the resulting mixture is formed into the desired shape through molding processes such as extrusion, injection molding, pressing or casting. During extrusion molding, a single-screw or twin-screw extruder can be used, and the appropriate mold can be selected according to the desired product shape. The temperature, pressure and screw speed of the extruder can be controlled to ensure the quality of product molding; during injection molding, the injection molding pressure, temperature and holding time and other parameters need to be accurately controlled to ensure that the material can completely fill the mold cavity and form a product with complete shape and precise size; during the pressing process, the pressing pressure and time should be reasonably adjusted according to the shape and thickness of the product to ensure uniform product density; during casting molding, the height and speed of the scraper should be controlled to spread the material evenly and form a film or sheet with uniform thickness.

[0061] Finally, the formed material is dried. Drying can be done in an oven with the temperature set at 90°C. During the drying process, the material should be turned over or ventilated regularly to ensure that the moisture can evaporate evenly until the moisture content is less than 5%. During the drying process, the moisture content of the product needs to be monitored. A moisture tester or drying method can be used to test the product to ensure that the degree of dryness meets the requirements. The entire drying process may take several hours to dozens of hours, and finally a degradable and environmentally friendly welding auxiliary material for marine engineering is obtained.

[0062] The natural degradable polymer is sodium alginate, chitosan, cellulose or a combination thereof.

[0063] The benefits of the above settings are:

[0064] 1. Degradability:

[0065] Environmental friendliness:

[0066] Sodium alginate is a natural polysaccharide extracted from brown algae, which has good biodegradability in the marine environment. It can be hydrolyzed by enzymes secreted by various microorganisms in the ocean, gradually decomposed into small molecules, and finally converted into harmless products such as carbon dioxide and water. This degradation process is highly compatible with the marine environment and will not exist for a long time like traditional synthetic polymers, avoiding persistent pollution to the marine environment, helping to protect the marine ecosystem and reduce the accumulation of solid waste in the ocean.

[0067] Chitosan is the product of chitin deacetylation, and can also be decomposed by microorganisms in the marine environment. Its degradation products are mainly simple sugars, amino acids and some inorganic salts, which can participate in the material cycle of the ocean and will not cause harm to marine life and ecosystems. Moreover, chitosan itself has certain antibacterial properties, which can prevent excessive growth of microorganisms on welding auxiliary materials to a certain extent, avoid adverse effects on material properties, and also help maintain the balance of marine microorganisms.

[0068] Cellulose is one of the most abundant natural polymers in nature. It will gradually hydrolyze into glucose under the action of microorganisms, and then further decompose through the metabolism of microorganisms. Using cellulose as an ingredient can take advantage of its good biodegradability to ensure that welding auxiliary materials can be naturally decomposed in the marine environment after being discarded, meeting environmental protection requirements.

[0069] Degradation speed and time controllability:

[0070] By combining sodium alginate, chitosan and cellulose, the degradation rate of the material can be adjusted according to actual needs. Different combination ratios can change the structure and chemical properties of the material, thereby affecting its degradation performance. For example, when sodium alginate and chitosan are mixed in a certain proportion, due to their different chemical structures and degradation mechanisms, a synergistic effect may occur, causing the material to achieve different degradation times and speeds under different marine environmental conditions. In some application scenarios that require short-term degradation, the proportion of sodium alginate can be appropriately increased; for applications that need to maintain performance for a longer period of time, the content of chitosan or cellulose can be increased to achieve effective control of the material degradation time to meet the construction and maintenance cycle requirements of different marine projects.

[0071] 2. Material performance:

[0072] Adhesion and Flexibility:

[0073] Sodium alginate has a certain viscosity, which can enhance the bonding performance of welding auxiliary materials on the welding surface, ensure that the auxiliary materials are firmly attached to the metal surface during welding, avoid falling off due to water flow, wave impact or vibration during welding operation, and improve the stability of the welding process. At the same time, it can give the material a certain flexibility, so that the material can better fit on welding parts of different shapes and complex structures, ensuring the smooth progress of welding operations.

[0074] Chitosan has good film-forming properties. When combined with sodium alginate or cellulose, it can form a denser network structure and enhance the overall performance of the material. This network structure helps to evenly disperse other ingredients in the material while improving the toughness of the material to prevent it from breaking or being damaged by external forces during welding operations or marine environments.

[0075] Cellulose has high strength. Adding it to the material can improve the mechanical properties of the material, enhance the material's tensile and tear resistance, make it less likely to be damaged when subjected to external forces, ensure the integrity of the auxiliary material during the welding process, and ensure that it can continue to play a role during welding.

[0076] Thermal and chemical stability:

[0077] These three natural biodegradable polymers all have certain thermal and chemical stability. During the welding process, higher temperatures and possible chemical release will be generated. They can withstand a certain degree of high temperature without decomposition, and can work together with other ingredients such as flux and antioxidants. They will not undergo rapid chemical changes due to high temperature or chemical substances, ensuring that the auxiliary materials remain stable in the high temperature environment of welding and play their auxiliary welding function.

[0078] 3. Cost and resource sustainability:

[0079] Resource richness:

[0080] Sodium alginate, chitosan and cellulose all come from natural resources and have a wide range of sources. Sodium alginate can be extracted in large quantities from algae, chitosan can be obtained from the shells of crustaceans such as shrimp and crabs, and cellulose is widely found in plants, such as wood and cotton. This means that the cost of obtaining raw materials is relatively low, and sustainable use of resources can be achieved, which is in line with the principle of sustainable development and reduces the production cost of materials.

[0081] Using these naturally degradable polymers as the main raw materials can also reduce dependence on non-renewable resources such as petroleum-based materials, promote the development of marine engineering materials in a green, environmentally friendly and sustainable direction, and provide resource guarantees for the long-term development of marine engineering.

[0082] The plasticizer is tributyl citrate, glycerol or polyethylene glycol.

[0083] The benefits of the above settings are:

[0084] 1. Improve material flexibility and plasticity:

[0085] Tributyl citrate:

[0086] As an excellent plasticizer, tributyl citrate can effectively improve the flexibility of welding auxiliary materials. In this material, it can be inserted between the molecular chains of natural degradable polymers (such as sodium alginate, chitosan, cellulose, etc.), reducing the intermolecular forces and making the molecular chains easier to move, thereby increasing the flexibility of the material. This flexibility is particularly important for welding auxiliary materials in marine engineering, because in different welding scenarios, auxiliary materials may need to be applied, sprayed or pasted on welding parts of various shapes, including curved surfaces, irregular surfaces, etc. Flexible materials can better fit these surfaces, ensuring that the auxiliary materials can be evenly covered when used, improving the convenience and effectiveness of use.

[0087] It can also improve the plasticity of the material, making it easier to process and shape. When preparing welding auxiliary materials through molding processes such as extrusion, injection molding or tableting, the addition of tributyl citrate can enable the material to pass through the mold better and form the desired shape, such as rods, sheets or powders, avoiding problems such as cracking or surface roughness of the material during the molding process, ensuring that the product has a good appearance and dimensional accuracy.

[0088] glycerin:

[0089] Glycerin has strong hygroscopicity and water retention. In welding auxiliary materials, it can maintain the moisture content of the material to a certain extent, preventing the material from being overly dry and becoming brittle during storage and use. Especially in the marine environment, the regulation of moisture content is crucial to the performance of the material, because the humidity of the marine environment is high, and glycerin can help the material better adapt to this environment and maintain the flexibility and plasticity of the material.

[0090] Glycerin is also an excellent plasticizer, which can make the material softer and prevent the auxiliary material from breaking when subjected to mechanical stress in the marine environment (such as wave impact, water flow impact, etc.), ensuring that it maintains good performance over a long service life. At the same time, it has good compatibility with natural degradable polymers and can be evenly dispersed in the material, enhancing the overall performance of the material and improving the material's ability to resist deformation.

[0091] Polyethylene glycol:

[0092] Polyethylene glycol has different molecular weights to choose from, and its molecular weight can be adjusted according to actual needs to change the performance of the material. It can give the material different degrees of flexibility to meet the requirements of different marine engineering applications. Low molecular weight polyethylene glycol can improve the fluidity of the material and facilitate the application and operation of the material; high molecular weight polyethylene glycol can enhance the toughness and strength of the material, so that the material will not be easily damaged when subjected to large external forces.

[0093] Polyethylene glycol also has good lubricity. During the use of the material, it helps to spread the auxiliary material on the welding surface, avoids the welding operation being affected by excessive friction between the material and the metal surface, ensures the uniform distribution of the auxiliary material on the welding part, and improves the quality and efficiency of the welding process.

[0094] 2. Environmental protection:

[0095] Low toxicity and biocompatibility:

[0096] Tributyl citrate is a recognized environmentally friendly plasticizer with low toxicity and minimal harm to marine life and the marine environment. In the marine environment, even if a small amount of tributyl citrate seeps or releases from welding auxiliary materials, it will not cause serious toxicity to marine life and will not interfere with the normal physiological activities of marine life, such as growth, reproduction and metabolism.

[0097] Glycerol is a natural product with good biocompatibility and high safety in the marine environment. During the material degradation process, no substances harmful to the marine ecosystem are produced, which meets the requirements of the present invention for environmentally friendly welding auxiliary materials and does not bring additional pollution burden to the marine environment.

[0098] Polyethylene glycol also has good biocompatibility and can be slowly degraded by microorganisms in the marine environment. Its degradation products are relatively harmless to marine life. Compared with traditional chlorine- or benzene-containing plasticizers, it greatly reduces the risk to the marine environment and ensures the environmental performance of welding auxiliary materials after use and disposal.

[0099] 3. Chemical stability and compatibility:

[0100] Synergy with other ingredients:

[0101] These plasticizers are well compatible with other components in the present invention, such as flux, binder, antioxidant, etc. During the preparation and use process, they will not chemically react with other components, ensuring the chemical stability of the entire welding auxiliary material. For example, when mixed with flux (such as borax, potassium fluoride, etc.), it will not affect the performance of the flux, ensuring that the flux can play a normal role in reducing slag viscosity and improving molten pool performance.

[0102] They work together with the binder to improve the overall performance of the material, enhance the adhesion and stability of the material on the welding surface. Under different marine environmental conditions, they can work in conjunction with other components to ensure the welding auxiliary function and environmental adaptability of the material.

[0103] The flux is borax, potassium fluoride, sodium fluoride, zinc chloride or a combination thereof.

[0104] The benefits of the above settings are:

[0105] 1. Improve the performance of welding pool:

[0106] Reduce slag viscosity:

[0107] Borax, as a flux, can significantly reduce the viscosity of slag during welding. When welding, the viscosity of slag is crucial to the quality of welding. Lower slag viscosity helps the flow and discharge of slag, preventing slag from accumulating in the weld to form defects such as slag inclusions. In marine engineering welding operations, such as welding of offshore platform structures or submarine pipelines, borax can ensure smooth slag flow, better fusion of metals in the molten pool, and improve the quality and appearance of the weld.

[0108] Potassium fluoride and sodium fluoride are also commonly used fluxes. They can react with metal oxides to form low-melting-point compounds, making the slag more fluid. Under high welding temperatures, they can effectively dissolve oxides on the metal surface, making the molten pool purer, promoting uniform mixing of metal elements in the molten pool, and avoiding the influence of oxide inclusions on the strength and toughness of the weld.

[0109] Zinc chloride can decompose into zinc ions and chloride ions at high temperatures. Zinc ions can react with metal oxides to lower the melting point of metal oxides, making the slag more fluid, helping to form a continuous and smooth weld and improving the density and firmness of the weld.

[0110] Adjust the physical and chemical properties of the molten pool:

[0111] The combination of these fluxes can adjust the physical and chemical properties of the molten pool. By using borax, potassium fluoride, sodium fluoride and zinc chloride in a reasonable combination, the surface tension of the molten pool can be controlled, making it more stable during the welding process, reducing metal splashing, and improving the safety and operability of the welding operation. For example, in the construction of offshore platforms, reducing metal splashing can prevent splashing from falling into the ocean and causing pollution and safety hazards to construction workers.

[0112] They help to improve the wettability of the molten pool, spread the molten metal better on the welding base material, increase the coverage of the weld, ensure a good bond between the weld and the base material, and enhance the strength of the weld joint, which is crucial for ensuring reliable connection strength for marine engineering structures subjected to high pressure and high stress, such as ship hulls and supporting components of offshore oil platforms.

[0113] 2. Improving welding quality:

[0114] Promote fusion and eliminate defects:

[0115] Flux can effectively remove the oxide film produced during welding by reacting with the oxide on the metal surface, making the metal at the weld purer and avoiding welding defects such as lack of fusion and pores caused by the presence of the oxide film. In the marine environment, the welding conditions are relatively complex, and the presence of these fluxes can ensure that high-quality welds can be obtained in environments such as high humidity and salt spray.

[0116] The combined use of these fluxes can bring out their respective advantages under different welding conditions. For example, when welding different metal materials (such as steel, aluminum alloy and other metals commonly used in marine engineering), the combination ratio of fluxes can be adjusted according to the properties of the materials and welding requirements to improve the adaptability of welding and ensure the welding quality of various marine engineering structural components.

[0117] 3. Environmental protection and safety:

[0118] Control the generation of harmful substances:

[0119] Although potassium fluoride, sodium fluoride and the like contain fluorine, their reaction products in the welding process can be effectively controlled through synergy with other ingredients when used reasonably and in controlled amounts. At the same time, due to the overall framework of biodegradable and environmentally friendly welding auxiliary materials, after welding, these fluxes and their reaction products can be processed by microorganisms or chemical processes in the marine environment together with other ingredients, reducing their long-term harm to the marine environment.

[0120] Borax is more environmentally friendly than some other traditional fluxes. It does not produce a large amount of toxic and harmful gases during the welding process. While meeting the welding requirements, it reduces the harm to the marine environment and construction workers. Zinc chloride is also relatively stable during the reaction process and does not produce substances that are highly toxic to marine life and the environment, ensuring the safety and environmental friendliness of the marine engineering construction process.

[0121] 4. Cost and resources:

[0122] Cost-effectiveness:

[0123] Borax, potassium fluoride, sodium fluoride and zinc chloride are all relatively easy to obtain and low-cost chemical raw materials, which helps to reduce the production cost of the entire welding auxiliary materials. In large-scale marine engineering, the use of these common and economical fluxes can achieve cost control while ensuring welding quality, thereby improving the economic benefits of marine engineering.

[0124] These fluxes have a wide range of sources and a stable supply, and production will not be affected by raw material shortages, ensuring the sustainable production and application of degradable and environmentally friendly welding auxiliary materials for marine engineering, and providing a reliable material foundation for the sustainable development of marine engineering.

[0125] The binder is starch, dextrin or gum arabic.

[0126] The benefits of the above settings are:

[0127] 1. Enhance material adhesion:

[0128] Improve the adhesion of welding auxiliary materials:

[0129] Starch has good bonding properties. When used in welding auxiliary materials, it can make the material firmly adhere to the metal surface of the welding part. In various welding operations in marine engineering, the welded parts may be affected by factors such as water flow impact, seawater erosion and mechanical vibration. Starch as a binder can ensure that the auxiliary materials still fit tightly to the metal surface under these conditions and will not fall off easily. For example, when welding the hull of a ship, the binder can prevent the auxiliary materials from being lost due to the scouring of seawater, ensuring that the auxiliary materials can play a stable role throughout the welding process.

[0130] Dextrin is also an excellent adhesive. It can form a tough film after drying. This film can bond the various components in the welding auxiliary materials together and bond the auxiliary materials to the welding area, so that the materials can still exist stably in complex marine environments, such as high humidity and high salinity environments, and ensure that the auxiliary materials continue to perform their due functions during the welding process, such as preventing oxidation and reducing spatter.

[0131] Gum Arabic has high viscosity and good film-forming properties. It can form a strong bond between auxiliary materials and different metal surfaces, including stainless steel, carbon steel, aluminum alloy and other metal materials commonly used in marine engineering. It can form a strong bonding coating on the welding surface, so that the auxiliary materials can withstand various complex situations in the marine environment, such as the impact of waves and the attachment of marine organisms, ensuring the integrity and effectiveness of the auxiliary materials.

[0132] 2. Environmental protection:

[0133] Natural Origin and Degradable:

[0134] Starch is a natural product, usually derived from plants such as corn and potatoes, and has good biodegradability in the marine environment. After the welding auxiliary materials are used, over time, the starch will be decomposed into simple sugars by microorganisms in the ocean, and eventually converted into carbon dioxide and water. Unlike some synthetic adhesives, it will not leave difficult-to-degrade residues in the ocean, thus avoiding long-term pollution to the marine environment.

[0135] As a hydrolysis product of starch, dextrin also has good biodegradability. Its degradation products are harmless to the marine environment and will not cause harm to marine organisms and ecosystems, which meets the requirements of the present invention for environmentally friendly welding auxiliary materials.

[0136] Gum arabic is a natural substance extracted from the exudate of the branches and trunks of the arabic tree. It can be degraded by microorganisms in the marine environment, and its degradation products will not interfere with the ecological balance of the ocean. It is a green and environmentally friendly choice that helps reduce the impact of marine engineering on the marine environment.

[0137] 3. Processing performance:

[0138] Conducive to material forming and processing:

[0139] In the process of preparing welding auxiliary materials, these binders can evenly mix and bond various ingredients together. When mixing various powdered or granular raw materials (such as flux, antioxidant, defoamer, etc.), starch, dextrin or gum arabic can be used as an effective bonding medium to ensure that components of different particle sizes and properties can be evenly dispersed in the material, making the performance of the material more uniform and consistent.

[0140] During the molding process, they help to make the material into the desired shape, such as paste, rod or powder. For example, when making paste auxiliary materials, binders can adjust the consistency of the material to make it easy to apply to the welding part; when making rod materials, they can ensure the molding strength of the material, prevent the rod from breaking during storage and use, and facilitate operation and use.

[0141] 4. Compatibility with other ingredients:

[0142] Works synergistically with other ingredients:

[0143] These binders have good compatibility with other components in the present invention (such as natural degradable polymers, plasticizers, fluxing agents, etc.). They will not have adverse chemical reactions with other components, and can ensure the chemical stability of the entire welding auxiliary material during storage and use. Under different temperature and humidity conditions, they can work together with other components to ensure the stable performance of the welding auxiliary material.

[0144] During the welding process, they can withstand high temperatures together with other components and will not lose their bonding ability due to high temperatures. At the same time, they will not interfere with the fluxing effect of the flux and the antioxidant function of the antioxidant, etc., ensuring the comprehensive performance of welding auxiliary materials during the welding process and improving the welding quality.

[0145] The antioxidant is vitamin C, tocopherol or propyl gallate.

[0146] The benefits of the above settings are:

[0147] 1. Preventing oxidation and deterioration of materials:

[0148] The performance of protective materials is stable:

[0149] As an antioxidant, vitamin C can effectively inhibit the oxidation reaction of welding auxiliary materials during storage and use. In the marine environment, welding auxiliary materials may be affected by oxygen, moisture and high temperature, and vitamin C can react with oxygen preferentially through its own redox reaction, thereby protecting other components in the material (such as natural degradable polymers, plasticizers, adhesives, etc.) from oxidation. This helps to maintain the original properties of the material, avoid problems such as discoloration, brittleness, and reduced viscosity of the material caused by oxidation, and ensure the stability of the auxiliary material during long-term storage and use.

[0150] Tocopherol, or vitamin E, has excellent antioxidant properties. It can capture free radicals, interrupt oxidation chain reactions, and prevent unsaturated bonds in materials from being oxidized, thereby extending the service life of the materials. For welding auxiliary materials used in marine engineering, which may be exposed to the marine atmosphere or seawater for a long time, tocopherol can prevent the aging of organic components in the materials, ensure that the flexibility, adhesion and other physical and chemical properties of the materials are not damaged by oxidation, and ensure the performance of the materials at different stages.

[0151] Propyl gallate can also prevent the oxidation reaction by providing hydrogen atoms, inhibit the oxidation of oily substances in the material (such as unsaturated bonds contained in certain plasticizers or natural degradable polymers), prevent the material from losing its original properties due to oxidation, and ensure the stability of the material under complex marine environmental conditions (such as high humidity, high salinity, high temperature, etc.).

[0152] 2. Environmental protection:

[0153] Friendly to the marine environment:

[0154] Vitamin C is a water-soluble antioxidant with good biocompatibility in the marine environment, and its decomposition products are basically non-toxic to marine organisms and seawater. When it is released from welding auxiliary materials into the marine environment, it will not have adverse effects on the physiological processes of marine organisms, will not destroy the marine ecological balance, and meets the requirements of environmentally friendly welding auxiliary materials.

[0155] Tocopherol is a natural antioxidant that is relatively safe in the marine environment. Tocopherol itself and its metabolites are not toxic to marine life. To a certain extent, it can be decomposed and utilized by marine microorganisms and will not remain for a long time, thus reducing the risk of pollution to the marine environment.

[0156] Although propyl gallate is a synthetic antioxidant, its decomposition products in the environment are relatively harmless and will not cause serious harm to marine life and marine ecosystems. Compared with some traditional antioxidants, it has lower potential environmental risks in the marine environment and helps protect the marine ecological environment.

[0157] 3. Synergistic effect with other ingredients:

[0158] Enhance the overall performance of the material:

[0159] These antioxidants work in synergy with other ingredients to help improve the overall performance of the entire welding auxiliary material. For example, when used with a binder, they can prevent the binder from losing its viscosity due to oxidation, ensuring that the binder continues to work during the welding process and firmly attaches the auxiliary material to the welding site. At the same time, they can also work with natural degradable polymers to prevent the degradation process of the polymer from being adversely affected by oxidation, ensuring that the degradability of the material in the marine environment is not disturbed.

[0160] During the storage and use of welding auxiliary materials, antioxidants can work together with other additives (such as flux, defoaming agents, etc.) to maintain the stability of the materials, ensuring that under different environmental conditions, the various properties of the materials (such as slag properties, anti-foaming properties, etc.) will not change due to oxidation, thereby ensuring the reliability and stability of the materials in marine engineering welding operations.

[0161] 4. Improving welding quality:

[0162] Ensure the stability of the welding process:

[0163] During the welding operation, the presence of antioxidants can ensure that the performance of welding auxiliary materials is not affected by oxidation, thereby ensuring the stability of the welding process. For example, it prevents the formation and discharge of slag due to oxidation and deterioration of auxiliary materials, ensuring the stability of the molten pool and the quality of the weld. In the welding process of marine engineering, complex environments and long-term operations may be involved. Antioxidants can ensure that auxiliary materials are always in the best condition, reduce welding defects caused by changes in material properties, such as pores, slag inclusions, etc., and improve the quality and strength of the weld.

[0164] The defoaming agent is polydimethylsiloxane.

[0165] The benefits of the above settings are:

[0166] 1. Eliminating foam:

[0167] Highly efficient defoaming performance:

[0168] Polydimethylsiloxane is a highly efficient defoaming agent that can quickly eliminate the foam generated during the preparation and use of welding auxiliary materials. During the preparation process, when various components are mixed and stirred, a large amount of foam may be generated due to stirring, chemical reaction or dissolution process. These foams will affect the uniformity and quality of the material. Polydimethylsiloxane can quickly reduce the surface tension of the foam and break the foam film, thereby eliminating the foam and ensuring the uniformity and consistency of the material.

[0169] During welding operations, especially when auxiliary materials are used at high temperatures, foam may be generated due to the decomposition or reaction of certain components. These foams will interfere with the welding process and affect the observation and operation of the molten pool. Polydimethylsiloxane can effectively inhibit the formation of foam and eliminate the generated foam, making the molten pool clearly visible, facilitating the construction personnel to accurately operate the welding process and ensure the welding quality.

[0170] 2. Stability:

[0171] Good chemical and thermal stability:

[0172] Polydimethylsiloxane has excellent chemical stability. Among the various components of welding auxiliary materials, it will not react chemically with other components (such as natural degradable polymers, flux, antioxidants, etc.), ensuring the chemical stability of the entire material during storage and use. This is crucial to ensure the long-term storage and use of welding auxiliary materials under different environmental conditions, and avoid the degradation of material performance due to the reaction of defoaming agents with other components.

[0173] It also has good thermal stability. In the high temperature environment that may be generated during the welding process, it can maintain its defoaming performance and will not fail or decompose due to high temperature. It will continue to play a defoaming role to ensure the smooth progress of the welding process.

[0174] 3. Impact on material properties:

[0175] No adverse effects on other properties of the material:

[0176] It will not have a negative impact on other properties of welding auxiliary materials. It will not change important properties of the material such as adhesion, degradability, and molten pool performance. For example, it will not affect the ability of the binder to make the auxiliary material adhere to the welding part, nor will it interfere with the flux's regulation of slag viscosity and molten pool performance, and it will not affect the antioxidant performance of the antioxidant, ensuring that the overall performance of the entire welding auxiliary material is not affected, ensuring that the material can meet the defoaming requirements while other aspects of performance can be performed normally.

[0177] 4. Environmental protection:

[0178] Relatively friendly to the marine environment:

[0179] Polydimethylsiloxane has low biological toxicity in the marine environment. When a small amount is released from welding auxiliary materials, it will not cause serious toxicity to marine life. Its residual amount in the marine environment is relatively small, and it will not significantly interfere with the physiological processes of marine life (such as respiration, metabolism, reproduction, etc.). It meets the environmental protection requirements of degradable and environmentally friendly welding auxiliary materials for marine engineering and will not cause serious pollution to the marine ecosystem.

[0180] The metal ion source is calcium nitrate, magnesium sulfate or ferrous sulfate.

[0181] The benefits of the above settings are:

[0182] 1. Chemical reactions involved in the welding process:

[0183] Improve the solidification and crystallization behavior of the molten pool:

[0184] Calcium nitrate decomposes into calcium ions and nitrate ions during welding. Calcium ions can participate in the solidification process of the molten pool, and as heterogeneous crystal nuclei, promote the crystallization of the metal and refine the grains of the weld metal. In the welding of marine engineering, such as the welding of offshore platform structures and submarine pipelines, refined grains help improve the strength and toughness of the welds and enhance the mechanical properties of the welded joints in harsh marine environments (such as high pressure, strong water flow impact, etc.).

[0185] The magnesium ions in magnesium sulfate also have a similar effect. They can affect the solidification dynamics of the molten pool and change the crystallization mode of the metal, thereby improving the microstructure of the weld. Its presence helps to form a denser and more uniform weld structure, reduce welding defects, and improve welding quality.

[0186] Ferrous ions in ferrous sulfate can react with other elements in the molten pool and participate in the solidification and crystallization process of the metal. Ferrous ions can inhibit the growth of grains to a certain extent, making the microstructure of the weld more fine and uniform, which is of great significance for improving the performance of welded joints, especially crack resistance and corrosion resistance, and meeting the long-term durability requirements of marine engineering structures.

[0187] Adjust the physicochemical properties of slag:

[0188] These metal ion sources can adjust the physical and chemical properties of the slag. For example, calcium ions and magnesium ions in calcium nitrate and magnesium sulfate can change the viscosity and fluidity of the slag, which helps to discharge the slag and avoid welding defects such as slag inclusion. During the welding process, the viscosity and fluidity of the slag need to be properly adjusted according to different welding materials and welding processes. The introduction of these metal ions can better adapt to various welding conditions in marine engineering.

[0189] Ferrous sulfate can affect the surface tension of the slag to a certain extent, making the behavior of the slag at high temperature more conducive to welding operation, ensuring that the slag can effectively cover the surface of the molten pool after formation, playing a role in protecting the molten pool, preventing metal oxidation and the intrusion of impurities, and improving the quality of the weld.

[0190] 2. Improving the corrosion resistance of welds:

[0191] Forming a protective layer or improving corrosion resistance:

[0192] The calcium ions in calcium nitrate can form a thin layer of calcium oxide protective layer on the surface of the weld, or work together with other elements to form a composite oxide film, which can protect the weld to a certain extent and improve the corrosion resistance of the weld in the marine environment. In the marine environment, metal structures are extremely susceptible to corrosion by seawater. Adding calcium nitrate as a metal ion source can improve the corrosion resistance of the weld and extend the service life of marine engineering structures.

[0193] The magnesium ions in magnesium sulfate can combine with other elements to form compounds with certain corrosion resistance on the surface of the weld, enhancing the corrosion resistance of the weld to seawater and marine atmosphere. This can reduce structural damage and safety hazards caused by corrosion for structures that are often exposed to seawater in marine engineering, such as ship hulls and underwater parts of offshore platforms.

[0194] The ferrous ions in ferrous sulfate can participate in the formation of some compounds with anti-corrosion properties. At the same time, it can also change the electrochemical properties of the weld metal to a certain extent, making the potential of the weld more conducive to corrosion resistance, thereby improving the corrosion resistance of the weld in the marine environment and ensuring the long-term stability of the marine engineering structure.

[0195] 3. Environmental protection and safety:

[0196] Friendly to the marine environment:

[0197] Calcium nitrate, magnesium sulfate and ferrous sulfate are relatively mild in the marine environment, and their decomposition products are less toxic to marine organisms. During the use of welding auxiliary materials, even if some ions of these metal ion sources diffuse into the marine environment, they will not cause serious toxicity to marine organisms and will not cause serious damage to the marine ecosystem. Their dissolution and diffusion processes in the ocean are relatively controllable, and they will not be enriched in marine organisms like some heavy metal ions, causing long-term ecological problems.

[0198] Compared with some traditional metal ion sources, these metal ion sources are more stable and safer in the marine environment. While meeting the welding performance requirements, they comply with the requirements of the present invention for environmentally friendly welding auxiliary materials and reduce potential risks to the marine environment.

[0199] 4. Cost and resources:

[0200] Economic and resource advantages:

[0201] Calcium nitrate, magnesium sulfate and ferrous sulfate are common chemical substances with wide sources and relatively low prices. In large-scale marine engineering, the use of these metal ion sources can effectively control the cost of welding auxiliary materials and will not increase the overall cost of marine engineering due to excessive raw material costs. At the same time, due to its abundant resources and easy access, it ensures a stable supply of materials and provides an economically feasible material choice for the sustainable development of marine engineering.

[0202] The biologically active additives are chitosan oligosaccharides, microbial preparations or marine biological extracts.

[0203] The benefits of the above settings are:

[0204] 1. Promoting material degradation:

[0205] Accelerated Degradability:

[0206] As a bioactive additive, chitosan oligosaccharide has the ability to promote microbial growth and metabolism. In the marine environment, it can stimulate the activity of marine microorganisms, making these microorganisms more actively decompose the degradable components in welding auxiliary materials, such as natural degradable polymers (sodium alginate, chitosan, cellulose, etc.). By providing a more suitable growth environment and nutrients for microorganisms, chitosan oligosaccharide can accelerate the degradation of materials, ensure that welding auxiliary materials can be decomposed in the marine environment as soon as possible after use, and reduce long-term pollution to the marine ecosystem.

[0207] Microbial preparations contain a variety of microorganisms or their metabolites. Adding them to welding auxiliary materials can directly introduce microorganisms with degradation capabilities. These microorganisms can use auxiliary materials as a nutrient source to quickly start and accelerate the degradation process of materials in the marine environment, so that the materials are converted into harmless substances in a relatively short period of time, meeting environmental protection requirements.

[0208] Biodegradation pathways of reinforced materials:

[0209] Marine biological extracts may contain a variety of natural bioactive substances, which can interact with microorganisms in the marine environment and open up new biodegradation pathways. For example, some marine biological extracts may contain special enzymes or microbial growth promoting factors, which can work together with marine microorganisms to decompose the complex components in the material, broaden the degradation pathway of the material in the marine environment, improve the degradation efficiency, and help achieve complete degradation of the material in the marine environment.

[0210] 2. Impacts on marine life and ecosystems:

[0211] Bio-Friendliness:

[0212] Chitosan oligosaccharides have certain biological activities. In the marine environment, their impact on marine life is relatively mild, and they even promote the growth and protect some marine life to a certain extent. For example, they can promote the growth of some beneficial microorganisms, regulate the community structure of marine microorganisms, and help maintain the balance of the marine ecosystem, rather than being toxic or interfering to marine life like some traditional additives.

[0213] At the right dosage, microbial agents can selectively promote the growth of beneficial microorganisms in the marine environment and inhibit the growth of harmful microorganisms. By regulating the microbial community, they can have a positive impact on the marine ecosystem, provide a healthier living environment for marine life, and avoid destroying the ecological balance of marine life due to the use of welding auxiliary materials.

[0214] Marine biological extracts usually come from natural marine organisms and have high compatibility with the marine ecosystem. Adding them to welding auxiliary materials can make the materials better integrated into the marine environment, reduce potential risks to marine organisms, and ensure that the materials have no negative impact on the survival and reproduction of marine organisms during use and degradation.

[0215] 3. Improve material performance:

[0216] Enhance the functionality of materials:

[0217] Chitosan oligosaccharides can interact with other ingredients to enhance the overall performance of the material. It may form a more stable structure with natural degradable polymers and improve the mechanical properties of the material, such as enhancing the toughness and strength of the material, making the material more able to withstand external forces such as water flow impact and wave beating in the marine environment, and ensuring that the material is not easily damaged during use.

[0218] Microorganisms in microbial preparations can work synergistically with other components of welding auxiliary materials. For example, they can improve the bonding or fluxing properties of materials. Metabolites secreted by some microorganisms may interact beneficially with fluxes or adhesives to improve the performance of materials during welding, such as improving the fluidity of slag and enhancing the adhesion of materials to the welding site.

[0219] 4. Environmental protection and sustainability:

[0220] Sustainable environmental solutions:

[0221] The use of these bioactive additives provides a sustainable solution for the environmental friendliness of welding auxiliary materials. They utilize existing biological resources and biological mechanisms in the marine environment to promote the degradation of materials and the protection of the marine ecosystem, rather than relying on traditional chemical methods, in line with the principle of sustainable development. By introducing natural bioactive substances, the impact of the entire welding auxiliary material on the marine environment during its life cycle is minimized, providing more environmentally friendly technical support for the sustainable development of marine engineering.

[0222] The ultraviolet absorber is a hydroxybenzotriazole or benzophenone compound.

[0223] The benefits of the above settings are:

[0224] 1. Anti-ultraviolet performance:

[0225] Prevent material aging:

[0226] Hydroxybenzotriazole is a highly efficient UV absorber that absorbs UV rays and converts them into harmless heat. In marine engineering, welding auxiliary materials may be exposed to sunlight, especially for welding structures on the sea surface or in shallow sea areas, where UV radiation is relatively strong. Hydroxybenzotriazole can effectively absorb UV rays and prevent them from causing photoaging of the materials. It can prevent the natural degradable polymers (such as sodium alginate, chitosan, cellulose, etc.) and other ingredients (such as plasticizers, adhesives, etc.) in the auxiliary materials from being degraded, discolored, brittle or losing their original properties due to UV irradiation, ensuring the stability of the material during long-term use and storage.

[0227] Benzophenone compounds also have good UV absorption capabilities. They can absorb UV energy through the conjugated structure within the molecule and protect the material from UV damage. These compounds can absorb UV within a certain wavelength range, form an excited state, and then dissipate the energy in the form of heat energy through intramolecular energy transfer and photophysical processes, thereby protecting the chemical structure of the material, avoiding chemical bond breakage and molecular structure damage caused by UV rays, and extending the service life of the material.

[0228] 2. Material stability:

[0229] Ensure stable performance of materials:

[0230] In the marine environment, the stability of materials is of vital importance. Due to the complexity of the marine environment, such as the combined influence of factors such as temperature, humidity, salinity and ultraviolet radiation, the performance of welding auxiliary materials is easily affected. Adding hydroxybenzotriazole or benzophenone compounds as ultraviolet absorbers can ensure that the material maintains stable performance under various environmental conditions. They can prevent the material from deteriorating under ultraviolet radiation, so that during storage and use, its important properties such as adhesion, flexibility, and molten pool performance are not affected by ultraviolet rays, ensuring that the welding auxiliary materials can normally play their auxiliary welding functions.

[0231] These UV absorbers can maintain the mechanical properties of materials in the marine environment, prevent problems such as surface cracking, peeling or strength loss caused by UV rays, and ensure the integrity of the materials during use, especially for welding auxiliary materials that need to be used for a long time or in an open-air marine environment, to ensure their reliability throughout the entire use cycle.

[0232] 3. Environmental protection:

[0233] Relatively friendly to the marine environment:

[0234] Hydroxybenzotriazole and benzophenone compounds have relatively little impact on the marine environment while playing the role of ultraviolet absorption. When these compounds are released into the marine environment from welding auxiliary materials in small quantities, they will not cause serious harm to marine life and marine ecosystems like some traditional UV protection additives. Their residual amount in the marine environment is relatively controllable, and their chemical properties are relatively stable. They will not have a significant adverse effect on the physiological processes of marine life (such as respiration, reproduction, metabolism, etc.), which meets the environmental protection requirements of degradable and environmentally friendly welding auxiliary materials for marine engineering.

[0235] 4. Compatibility with other ingredients:

[0236] Works synergistically with other ingredients:

[0237] Hydroxybenzotriazole and benzophenone compounds have good compatibility with other ingredients in the present invention (such as natural degradable polymers, plasticizers, binders, fluxes, etc.). They will not react adversely with other ingredients, and can work in synergy with other ingredients in the entire material system to ensure the stability and comprehensive performance of welding auxiliary materials under different environmental conditions. During storage and use, they will not interfere with the normal functions of other ingredients, for example, they will not affect the bonding effect of the binder, nor will they affect the fluxing performance of the flux, ensuring that the performance of the material at different stages is not affected.

[0238] Effect Test of Embodiment

[0239] In order to comprehensively evaluate the performance of the biodegradable and environmentally friendly welding auxiliary material for marine engineering of the present invention, a series of rigorous effect tests were conducted. The following are the specific test contents and results:

[0240] 1. Degradation performance test:

[0241] The degradable and environment-friendly welding auxiliary material of the present invention is prepared into a standard sample and placed in a test container simulating a marine environment. The test container contains seawater taken from a natural sea area and is inoculated with a variety of common marine microorganisms to simulate the real environmental conditions in the ocean. Within a certain time period (for example, for a period of 1 year), the sample is regularly observed and analyzed. First, from the appearance, as time goes by, the sample gradually undergoes physical changes, and its surface gradually becomes rough and loose from the initial complete and smooth state, and some samples even show obvious signs of fragmentation and decomposition. At the same time, by using chemical analysis methods, by sampling and analyzing the seawater in the test container, it is found that the natural degradable polymers in the material, such as sodium alginate, chitosan and cellulose, are gradually decomposed into small molecular compounds under the action of microorganisms. These small molecular compounds are tested and are mainly carbon dioxide, water, and some harmless organic acids and sugars, etc., and no substances toxic to marine organisms are detected. In addition, the addition of bioactive additives significantly accelerated the degradation process of the material. By promoting the growth and metabolic activities of marine microorganisms, the material began to degrade in a relatively short period of time, indicating that the material of the present invention has good degradability in the marine environment and will not remain for a long time like traditional welding auxiliary materials, posing a continuous pollution threat to the marine ecosystem.

[0242] 2. Welding performance test:

[0243] Under simulated marine engineering welding conditions, the welding auxiliary material of the present invention was compared with the traditional welding auxiliary material. The same welding process was used to weld metal materials of the same specifications. During the welding process, it was observed that when the auxiliary material of the present invention was used, the formation and flow of slag were smoother, and the flux component effectively reduced the viscosity of the slag, making the slag more fluid, avoiding the accumulation of slag and the generation of slag inclusions. By testing the weld after welding, it was found that the appearance of the weld was more uniform and smooth, without obvious pores and cracks, which was due to the binder ensuring the firm adhesion of the auxiliary material to the welding part, preventing quality problems caused by splashing and molten pool stirring. The hardness of the weld was tested using a hardness tester. The results showed that the hardness of the weld welded using the auxiliary material of the present invention met the requirements of marine engineering, and compared with the weld using traditional auxiliary materials, the hardness distribution was more uniform, indicating that the auxiliary material of the present invention helps to form a weld with better quality. The mechanical properties of the welds were evaluated through tensile tests and impact tests. The joints welded with the auxiliary materials of the present invention showed high tensile strength and good impact resistance, indicating that they can provide reliable connection strength in harsh marine environments and ensure the stability and safety of marine engineering structures.

[0244] 3. Environmental impact test:

[0245] In order to evaluate the potential impact of the material on the marine environment, the auxiliary material of the present invention was placed in a seawater environment containing marine biological seedlings (such as algae and shellfish larvae) in another test container. After a certain exposure time, the growth and survival of the marine organisms were observed, and it was found that compared with the control group of traditional welding auxiliary materials, the auxiliary material of the present invention had almost no negative impact on the growth and survival of marine biological seedlings. This shows that the components in the material of the present invention will not interfere with the physiological functions of marine organisms, and its low toxicity and environmental protection characteristics have been verified. At the same time, through continuous monitoring of the chemical properties of seawater, including indicators such as pH, dissolved oxygen, salinity and heavy metal content, the chemical properties of seawater remained basically stable throughout the test process, and no obvious changes caused by the release of substances from the auxiliary materials occurred, further proving the friendliness of the material of the present invention to the marine environment.

[0246] 4. Stability test:

[0247] Samples of the welding auxiliary material of the present invention were placed under different marine environment simulation conditions, including high humidity, high salinity, ultraviolet irradiation and temperature fluctuations. After a period of exposure, the performance of the material was tested, and it was found that the antioxidant and ultraviolet absorber played a good role. The antioxidant effectively inhibited the oxidation process of the material in a high humidity and high salinity environment, ensuring the stability of the material performance; while the ultraviolet absorber protected the material from significant aging and performance degradation under long-term ultraviolet irradiation. Through comparative tests, it can be seen that the control group material without adding antioxidants and ultraviolet absorbers has a significant decline in performance under the same conditions, such as discoloration, brittleness and poor adhesion, while the material of the present invention with these ingredients added still maintains good flexibility, adhesion and welding auxiliary performance, proving that the material of the present invention has good stability and reliability under various marine environmental conditions.

[0248] Through the above series of effect tests, the degradable and environmentally friendly welding auxiliary material for marine engineering of the present invention performs well in degradation performance, welding performance, environmental impact and stability, and has significant advantages. It provides a green, environmentally friendly and high-performance auxiliary material selection for welding operations in marine engineering, and can effectively solve the problems of environmental pollution and performance limitations caused by traditional welding auxiliary materials, and meet the needs of marine engineering for sustainable development and safety and reliability.

[0249] The examples given in the present invention are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here, and the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A degradable and environmentally friendly welding auxiliary material for marine engineering, characterized in that: The invention is composed of the following raw materials in parts by weight: 30-50 parts of natural degradable polymer, 8-12 parts of plasticizer, 12-18 parts of flux, 10-15 parts of binder, 4-7 parts of antioxidant, 2-4 parts of defoamer, 3-6 parts of metal ion source, 2-5 parts of bioactive additive and 1-3 parts of ultraviolet absorber.

2. The degradable and environmentally friendly welding auxiliary material for marine engineering according to claim 1, characterized in that: The natural degradable polymer is sodium alginate, chitosan, cellulose or a combination thereof.

3. The degradable and environmentally friendly welding auxiliary material for marine engineering according to claim 1, characterized in that: The plasticizer is tributyl citrate, glycerol or polyethylene glycol.

4. The degradable and environmentally friendly welding auxiliary material for marine engineering according to claim 1, characterized in that: The flux is borax, potassium fluoride, sodium fluoride, zinc chloride or a combination thereof.

5. The degradable and environmentally friendly welding auxiliary material for marine engineering according to claim 1, characterized in that: The binder is starch, dextrin or gum arabic.

6. The degradable and environmentally friendly welding auxiliary material for marine engineering according to claim 1, characterized in that: The antioxidant is vitamin C, tocopherol or propyl gallate.

7. The degradable and environmentally friendly welding auxiliary material for marine engineering according to claim 1, characterized in that: The defoaming agent is polydimethylsiloxane.

8. The degradable and environmentally friendly welding auxiliary material for marine engineering according to claim 1, characterized in that: The metal ion source is calcium nitrate, magnesium sulfate or ferrous sulfate.

9. The degradable and environmentally friendly welding auxiliary material for marine engineering according to claim 1, characterized in that: The bioactive additive is chitosan oligosaccharide, microbial preparation or marine biological extract; the ultraviolet absorber is hydroxybenzotriazole or benzophenone compound.

10. The degradable and environmentally friendly welding auxiliary material for marine engineering according to claim 1, characterized in that: The preparation method The following steps are involved: The first step: weigh each raw material by weight; Step 2: Add the natural degradable polymer into an appropriate amount of water and stir evenly to form a solution or dispersion; Step 3: Add plasticizer, flux, binder, antioxidant, defoamer, metal ion source, bioactive additive and ultraviolet absorber in sequence and stir evenly; Step 4: Form the mixture into the desired shape through a molding process; Step 5: Dry the molding material to make its moisture content less than 5%, and finally obtain a degradable and environmentally friendly welding auxiliary material for marine engineering.