Surface treatment process for high-performance stainless steel seamless tube

Abstract

The invention discloses a surface treatment process for a high-performance stainless steel seamless tube, and belongs to the technical field of seamless tube treatment. Comprising the following steps of pretreatment, titanium nitride film plating, silicon carbide coating growth, gradient buffer layer preparation, nano slow-release antibacterial coating coating, self-repairing coating arrangement, intelligent monitoring film deposition, anti-scaling coating growth and environment-friendly energy-saving treatment, and comprehensive improvement of performance and environmental protection is achieved through multi-technology collaborative innovation. The nanoscale titanium nitride film and the silicon carbide coating form a basic protective layer, the former prevents chloride ions from permeating, the latter enhances wear resistance, and the gradient metal ceramic buffer layer is matched to relieve thermal stress, so that the corrosion resistance and wear resistance of the pipeline under complex working conditions are jointly improved. All the effects are mutually associated and supplement each other, a closed loop is formed from multiple dimensions of protection, monitoring, repairing, energy saving and the like, the service life of the pipeline is remarkably prolonged, the maintenance cost is reduced, and the safety and sustainability of industrial production are improved.

Description

Technical Field

[0001] This invention relates to the field of seamless tube processing technology, and in particular to a high-performance stainless steel seamless tube surface treatment process. Background Technology

[0002] In modern industry, stainless steel seamless pipes, with their high strength and corrosion resistance, have become essential materials in many critical fields. In deep-sea oil and gas extraction, they serve as core pipelines for transporting oil and gas, enduring long-term high pressure, high salinity seawater, complex ocean currents, and microbial erosion. In chemical transportation scenarios, they must withstand various corrosive chemical media. In energy transmission, they must cope with complex conditions such as high temperature, high pressure, and mechanical vibration. Therefore, the quality of the surface treatment process for stainless steel seamless pipes directly determines the pipeline's service life, safety, and the continuity of industrial production.

[0003] However, existing surface treatment processes for stainless steel seamless pipes are insufficient to meet the demands of complex operating conditions. In terms of corrosion resistance, conventional processes cannot effectively resist the damage to the passivation film caused by chloride ions in high-salinity seawater, easily leading to pitting corrosion and threatening the pipe's strength and sealing. Regarding wear resistance, the surface treatment layer is easily worn away and peeled off by ocean currents, mechanical vibrations, and chemical media, shortening the pipe's service life. Furthermore, traditional processes have significant shortcomings in microbial corrosion protection, pipe surface condition monitoring, internal scaling prevention, and environmental protection and energy conservation. They cannot inhibit microbial erosion, lack real-time monitoring methods, are difficult to prevent internal scaling, and are energy-intensive and polluting, which is inconsistent with the concept of green development. Therefore, to solve these problems, the existence of a high-performance surface treatment process for stainless steel seamless pipes is crucial. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a high-performance surface treatment process for seamless stainless steel tubes, solving the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a high-performance stainless steel seamless tube surface treatment process, comprising the following steps: S1. Pretreatment: The stainless steel seamless pipe is pretreated by high-pressure water jet cleaning, mixed acid solution pickling, deionized water rinsing and drying to remove oil, rust, oxide scale and impurities from the pipe surface. S2. Depositing a titanium nitride thin film: A nano-scale titanium nitride thin film with a thickness of 500-800 nm is deposited on the pretreated pipe surface using magnetron sputtering technology. S3. Growth of silicon carbide coating: A silicon carbide coating is grown on a titanium nitride film by chemical vapor deposition, wherein the thickness of the silicon carbide coating is 1-2 μm; S4. Preparation of gradient buffer layer: A metal-ceramic buffer layer with gradient composition and properties is prepared between a titanium nitride thin film and a silicon carbide coating using plasma spraying technology. The thickness of the metal-ceramic buffer layer is 300-500 μm. S5. Coating a nano-slow-release antibacterial coating: Coating a nano-slow-release antibacterial coating containing nano-silver particles and a slow-release carrier onto the surface of the gradient buffer layer, wherein the thickness of the nano-slow-release antibacterial coating is 50-100μm; S6. Set a self-healing coating: Set a self-healing coating on the nano-slow-release antibacterial coating. The self-healing coating includes a micron-sized hollow capsule containing a repairing agent and a transparent polyurethane protective layer. S7. Depositing intelligent monitoring film: Depositing a graphene-metal oxide composite film between a gradient buffer layer and a silicon carbide coating to achieve intelligent monitoring; S8. Growth of anti-scaling coating: A superhydrophobic anti-scaling coating is formed by growing a fluorinated carbon nanotube coating on the inner wall of the pipe using chemical vapor deposition. S9. Environmentally friendly and energy-saving treatment: The waste acid liquid generated from pickling is treated by ion exchange resin adsorption and membrane filtration for recycling, and the energy consumption and material usage of magnetron sputtering and chemical vapor deposition are optimized.

[0006] Furthermore, the mixed acid solution consists of 5%-10% nitric acid and 2%-5% hydrofluoric acid, and the pickling temperature is 40-60℃ for 15-30 minutes.

[0007] Furthermore, during the magnetron sputtering process, the vacuum chamber is equipped with a vacuum level of 10⁻³-10⁻⁴ Pa. A titanium target with a purity of 99.9% is used as the sputtering target material. A mixture of argon and nitrogen is introduced, with an argon flow rate of 50-80 sccm and a nitrogen flow rate of 10-20 sccm. The DC voltage of the target material is 300-500V, and the sputtering time is 60-90 minutes. Under these pickling conditions, the oxide scale and impurities on the stainless steel surface can be removed more thoroughly, improving the adhesion between the subsequent coating and the substrate, thereby enhancing the overall protective performance.

[0008] Furthermore, during the chemical vapor deposition growth of the silicon carbide coating, methane, silane, and hydrogen are introduced. The methane flow rate is 20-30 sccm, the silane flow rate is 10-15 sccm, the hydrogen flow rate is 100-150 sccm, the reactor temperature is 1000-1200℃, and the reaction time is 120-180 minutes. These parameter settings can precisely control the growth rate and quality of the titanium nitride film, resulting in a film with high density and good uniformity, effectively blocking chloride ion penetration, and enhancing the pipeline's resistance to pitting corrosion.

[0009] Furthermore, when preparing the metal-ceramic buffer layer by plasma spraying, the distance between the spray gun and the pipe surface is 80-100mm, the plasma gas is a mixture of argon and hydrogen, the argon flow rate is 30-50 slpm, the hydrogen flow rate is 5-10 slpm, and the spray gun current is 100-150A. Such spraying parameters can make the composition gradient of the metal-ceramic buffer layer uniform, effectively alleviate the thermal stress caused by the difference in thermal expansion coefficients between different coatings, and enhance the overall resistance of the coating to mechanical damage.

[0010] Furthermore, the nano-silver particles in the nano-slow-release antibacterial coating have a particle size of 20-50nm and a mass fraction of 1%-3%. The coating is applied by dip coating or spray coating. During dip coating, the pipe is immersed in the coating for 1-2 minutes. During spray coating, the spray gun pressure is 0.3-0.5MPa, the spraying distance is 150-200mm, the curing temperature is 60-80℃, and the curing time is 2-3 hours. This design allows the nano-silver particles to be uniformly dispersed in the coating and slowly released through the slow-release carrier, achieving long-term effective inhibition of microorganisms and preventing microbial corrosion of the pipe.

[0011] Furthermore, the self-healing coating contains micron-sized hollow capsules with an average particle size of 10-20 μm, which are dispersed on the surface of the nano-slow-release antibacterial coating by spin coating. The transparent polyurethane protective layer has a thickness of 30-50 μm and is also dispersed on the surface of the nano-slow-release antibacterial coating by spin coating. When micro-cracks appear on the pipe surface, the hollow capsules rupture and release the repair agent, which can automatically fill the cracks and repair coating damage without manual intervention, reducing maintenance costs and safety hazards.

[0012] Furthermore, the graphene-metal oxide composite film has a thickness of 100-200nm and is deposited using magnetron sputtering technology. This film has good conductivity and environmental sensitivity, enabling real-time monitoring of pipeline surface damage and transmitting resistance change data to the monitoring center to achieve early warning of pipeline status, facilitating timely maintenance measures.

[0013] Furthermore, the fluorinated carbon nanotube coating has a diameter of 5-10 nm and a length of 0.5-1 μm. Due to its superhydrophobic properties, the contact angle of water droplets on its surface can reach more than 150°, which can effectively prevent the adhesion of minerals and impurities in the fluid, avoid scaling inside the pipe, and improve fluid transport efficiency.

[0014] Furthermore, the environmentally friendly and energy-saving treatment includes: The pickling waste acid solution is treated by ion exchange resin adsorption and membrane filtration for recovery; By employing new energy-saving equipment and optimizing gas flow ratios and improving equipment vacuum in the magnetron sputtering and chemical vapor deposition processes, this treatment method can significantly reduce waste acid discharge, lower energy consumption and harmful gas generation, making the entire surface treatment process greener and more environmentally friendly, and in line with the requirements of sustainable development.

[0015] This invention provides a high-performance surface treatment process for seamless stainless steel tubes, which has the following beneficial effects: Through multi-technology collaborative innovation, a comprehensive improvement in performance and environmental protection has been achieved. A nano-scale titanium nitride film and a silicon carbide coating form the basic protective layer; the former blocks chloride ion penetration, while the latter enhances wear resistance. Combined with a gradient metal-ceramic buffer layer to alleviate thermal stress, they jointly improve the pipeline's corrosion and wear resistance under complex operating conditions. A graphene-metal oxide composite film monitors the surface condition in real time; once damage is detected, microcapsules in the self-healing coating rupture to release a repair agent to fill cracks, ensuring the integrity of the protective layer. A fluorinated carbon nanotube superhydrophobic coating prevents internal scaling, ensuring fluid transport efficiency and reducing the risk of wear and corrosion caused by scaling. The recycling and treatment of pickling waste acid and energy-saving optimization of the process reduce both environmental impact and cost. These effects are interconnected and complementary, forming a closed loop from multiple dimensions including protection, monitoring, repair, and energy saving, significantly extending pipeline service life, reducing maintenance costs, and improving the safety and sustainability of industrial production. A multi-layered composite protection system was constructed by depositing a nano-scale titanium nitride thin film using magnetron sputtering and growing a silicon carbide coating using chemical vapor deposition, combined with a gradient cermet buffer layer. The nano-scale titanium nitride thin film effectively blocks chloride ion penetration, while the silicon carbide coating possesses extremely high hardness, resisting wear in complex environments. Experimental results have verified that pipelines treated with this process exhibit 3-5 times greater resistance to pitting corrosion in high-salinity seawater and 2-3 times longer wear resistance under strong ocean currents. Traditional processes struggle to simultaneously achieve both corrosion resistance and wear resistance, significantly improving the reliability and service life of pipelines under harsh operating conditions.

[0016] By depositing a graphene-metal oxide composite film between a gradient buffer layer and a silicon carbide coating, and combining it with external micro-sensors and a wireless transmission module, real-time monitoring and early warning of corrosion, wear, and other damage to pipeline surfaces are achieved. When the pipeline surface condition changes, the resistance value of the composite film changes, and the data is transmitted to the monitoring center in real time. Compared with the lag of traditional manual periodic inspections, this process can detect problems in advance, enabling maintenance personnel to take timely measures, reduce the probability of accidents, and minimize economic losses.

[0017] By incorporating a self-healing coating onto a nano-slow-release antibacterial coating, when microscopic cracks appear on the pipeline surface, micron-sized hollow capsules containing a repair agent rupture, releasing the repair agent to automatically fill the cracks, thus achieving self-repair of the coating. This function significantly improves pipeline durability, reduces maintenance frequency and costs, and is particularly suitable for complex environments such as the deep sea where manual maintenance is difficult, ensuring long-term stable pipeline operation.

[0018] By growing a superhydrophobic and anti-scaling coating of fluorinated carbon nanotubes on the inner wall of the pipe, the coating has extremely low surface energy and a water droplet contact angle of over 150°, effectively preventing the adhesion of minerals and impurities in the fluid and avoiding scale formation. Practical application tests have shown that pipes treated with this process reduce scale formation by more than 80% in chemical fluid transportation, significantly improving fluid transport efficiency and reducing the risk of pipe blockage caused by scale.

[0019] By treating pickling waste acid liquid with ion exchange resin adsorption and membrane filtration, acid liquid recycling is achieved, reducing emissions. New energy-saving equipment and optimized process parameters are used in processes such as magnetron sputtering and chemical vapor deposition to further reduce energy consumption. Calculations show that this process reduces energy consumption by 20%-30% compared to traditional processes and reduces harmful substance emissions by more than 50%, aligning with the modern industrial trend towards green and environmentally friendly development. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the process flow for a high-performance stainless steel seamless tube surface treatment process according to the present invention.

[0021] Figure 2 This is a schematic diagram of the experimental comparison process of a high-performance stainless steel seamless tube surface treatment technology according to the present invention. Detailed Implementation

[0022] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Example 1 like Figures 1-2 As shown, according to one aspect of the present invention, a technical solution is provided: a surface treatment process for high-performance stainless steel seamless tubes, comprising the following steps: Step 1: Pretreatment: Select a seamless stainless steel pipe with an outer diameter of 108mm and a wall thickness of 8mm. First, use a high-pressure water jet with a pressure of 25MPa to clean the surface of the pipe to remove visible oil and impurities. Then, immerse the pipe in a mixed acid solution composed of 8% nitric acid and 3% hydrofluoric acid and pickle it at 50℃ for 20 minutes to fully remove the surface oxide scale. After pickling, rinse the pipe repeatedly with deionized water to remove residual acid. Finally, place it in a 90℃ constant temperature drying oven to dry for 30 minutes.

[0024] Step 2: Depositing Titanium Nitride Thin Film: Place the pretreated pipe into the vacuum chamber of the magnetron sputtering coating equipment and evacuate to 10°C. -3 Pa; using a titanium target with a purity of 99.9% as the sputtering target, a mixture of argon (flow rate 65 sccm) and nitrogen (flow rate 15 sccm) was introduced; a DC voltage of 400V was applied to the target, and magnetron sputtering was performed for 80 minutes to form a titanium nitride film with a thickness of about 650 nm on the surface of the pipe.

[0025] Step 3: Growth of silicon carbide coating: Place the pipe coated with titanium nitride film into the CVD reactor and introduce methane (flow rate 25 sccm), silane (flow rate 12 sccm) and hydrogen (flow rate 120 sccm); raise the reactor temperature to 1100℃ and react for 150 minutes to grow a silicon carbide coating with a thickness of about 1.5 μm on the titanium nitride film.

[0026] Step 4: Preparation of gradient buffer layer: A coating powder is prepared by mixing nickel-chromium alloy and alumina-titanium oxide composite material in a gradient ratio. The pipeline is fixed on the rotating worktable of the plasma spraying equipment, and the distance between the spray gun and the pipeline surface is adjusted to 90mm. Argon (flow rate 40slpm) and hydrogen (flow rate 8slpm) are used as plasma gases. A current of 120A is applied to the spray gun to form a 400μm thick metal-ceramic gradient buffer layer.

[0027] Step 5: Applying a nano-slow-release antibacterial coating: Mix 30nm nano-silver particles (2% by mass) with polyurethane acrylate and add acetone to prepare a coating. Apply the coating to the pipe surface using a spraying method at a spray gun pressure of 0.4MPa and a spraying distance of 180mm. Then cure in a 70℃ curing oven for 2.5 hours to form a nano-slow-release antibacterial coating with a thickness of about 80μm.

[0028] Step 6: Set up a self-healing coating: Disperse micron-sized hollow capsules with an average particle size of 15μm containing epoxy resin and curing agent on the surface of the nano-slow-release antibacterial coating by spin coating, and then coat a 40μm thick transparent polyurethane protective layer.

[0029] Step 7: Deposit the intelligent monitoring film: Using magnetron sputtering technology, a 150nm thick graphene-metal oxide composite film is deposited between the gradient buffer layer and the silicon carbide coating.

[0030] Step 8: Growth of anti-scaling coating: A superhydrophobic anti-scaling coating of fluorinated carbon nanotubes with a diameter of 8 nm and a length of 0.8 μm is grown on the inner wall of the pipe using chemical vapor deposition.

[0031] Step 9, Environmental Protection and Energy Saving Treatment: The waste acid liquid generated from pickling is treated by ion exchange resin adsorption and membrane filtration for recovery; in the magnetron sputtering and chemical vapor deposition processes, new energy-saving equipment is adopted, the gas flow ratio is optimized, and the equipment vacuum degree is improved to reduce energy consumption.

[0032] Step 10: Comparative Experiment of Surface Treatment Processes for High-Performance Stainless Steel Seamless Tubes To verify the superiority of this high-performance stainless steel seamless tube surface treatment process, the following comparative experiment was designed. 304 stainless steel seamless tubes of the same specifications (outer diameter 108mm, wall thickness 8mm) were selected. One group used the traditional surface treatment process as the control group, and the other group used the process of this invention as the experimental group. Performance tests were conducted under simulated actual working conditions.

[0033] I. Corrosion Resistance Test Two groups of pipes were immersed in a simulated deep-sea high-salinity environment (3.5% sodium chloride solution, pH 7.5, temperature 25℃) for 120 days, and the surface corrosion was observed and the pitting depth was measured regularly. The results showed that the control group pipes had a large number of dense pits on the surface, with an average pitting depth of 0.8 mm, and the passivation film in some areas was severely damaged; while the experimental group, due to the effective protection of the nano-scale titanium nitride film, had only a few slight pitting traces on the surface, with an average pitting depth of only 0.15 mm, and its pitting resistance was more than 5 times that of the control group.

[0034] II. Wear Resistance Test A wear testing machine was used to simulate complex ocean current impact conditions, applying friction of the same frequency and force to two groups of pipelines for 500 hours. After the test, the surface treatment layer of the control group showed significant wear and peeling, with the surface roughness increasing to Ra3.2μm; the experimental group, thanks to the synergistic effect of the silicon carbide coating and gradient buffer layer, showed only slight surface wear, with the roughness increasing to Ra0.8μm, and the wear resistance life extended by 2.3 times.

[0035] III. Antimicrobial Corrosion Performance Test Two groups of pipes were cultured in a medium containing sulfate-reducing bacteria (SRB) for 30 days, and the amount of microbial adhesion and corrosion rate on the pipe surface were measured. The results showed that, due to the lack of effective antibacterial measures, the control group experienced a large proliferation of microorganisms, resulting in a corrosion rate of 0.25 mm / year; the experimental group, with its nano-slow-release antibacterial coating, continuously released nano-silver particles, effectively inhibiting microbial growth, reducing the amount of microbial adhesion by 90%, and lowering the corrosion rate to 0.03 mm / year.

[0036] IV. Anti-scaling performance test After running for 200 hours in a simulated chemical fluid transportation environment (fluid containing scaling substances such as calcium carbonate and calcium sulfate, temperature 60℃, flow rate 2m / s), the scaling conditions on the inner walls of the two groups of pipes were compared. The control group had a scaling thickness of up to 1.2mm on the inner wall, which seriously affected fluid transportation; the experimental group, thanks to its fluorinated carbon nanotube superhydrophobic coating, had very little scaling, with a scaling thickness of only 0.1mm, reducing scaling by more than 90% and effectively ensuring pipeline transportation efficiency.

[0037] V. Verification of Self-Repair and Intelligent Monitoring Functions Micro-cracks, approximately 0.2 mm deep, were artificially created on the surfaces of two groups of pipes, and the repair process was observed. In the experimental group, the self-healing coating automatically filled the cracks within 24 hours, restoring the surface to a smooth state; the control group, however, showed no repair capability, and the cracks persisted. Simultaneously, by simulating a pipe surface corrosion scenario, the graphene-metal oxide composite film monitoring system in the experimental group detected a change in resistance within 10 seconds of damage occurring and successfully transmitted the data to the monitoring terminal, achieving early warning; the control group lacked this function.

[0038] VI. Table Statistics

[0039] The above comparative experiments show that the surface treatment process for high-performance stainless steel seamless tubes of the present invention is significantly superior to traditional processes in terms of corrosion resistance, wear resistance, antimicrobial corrosion, anti-scaling, self-repair, and intelligent monitoring, effectively improving the comprehensive performance and service life of stainless steel seamless tubes under complex working conditions.

[0040] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A surface treatment process for high-performance stainless steel seamless tubes, characterized in that, Includes the following steps: S1. Pretreatment: The stainless steel seamless pipe is pretreated by high-pressure water jet cleaning, mixed acid solution pickling, deionized water rinsing and drying to remove oil, rust, oxide scale and impurities from the pipe surface. S2. Depositing a titanium nitride thin film: A nano-scale titanium nitride thin film with a thickness of 500-800 nm is deposited on the pretreated pipe surface using magnetron sputtering technology. S3. Growth of silicon carbide coating: A silicon carbide coating is grown on a titanium nitride film by chemical vapor deposition, wherein the thickness of the silicon carbide coating is 1-2 μm; S4. Preparation of gradient buffer layer: A metal-ceramic buffer layer with gradient composition and properties is prepared between a titanium nitride thin film and a silicon carbide coating using plasma spraying technology. The thickness of the metal-ceramic buffer layer is 300-500 μm. S5. Coating a nano-slow-release antibacterial coating: Coating a nano-slow-release antibacterial coating containing nano-silver particles and a slow-release carrier onto the surface of the gradient buffer layer, wherein the thickness of the nano-slow-release antibacterial coating is 50-100μm; S6. Set a self-healing coating: Set a self-healing coating on the nano-slow-release antibacterial coating. The self-healing coating includes a micron-sized hollow capsule containing a repairing agent and a transparent polyurethane protective layer. S7. Depositing intelligent monitoring film: Depositing a graphene-metal oxide composite film between a gradient buffer layer and a silicon carbide coating to achieve intelligent monitoring; S8. Growth of anti-scaling coating: A superhydrophobic anti-scaling coating is formed by growing a fluorinated carbon nanotube coating on the inner wall of the pipe using chemical vapor deposition. S9. Environmentally friendly and energy-saving treatment: The waste acid liquid generated from pickling is treated by ion exchange resin adsorption and membrane filtration for recycling, and the energy consumption and material usage of magnetron sputtering and chemical vapor deposition are optimized.

2. The surface treatment process for high-performance stainless steel seamless tubes according to claim 1, characterized in that: The mixed acid solution consists of 5%-10% nitric acid and 2%-5% hydrofluoric acid, and the pickling temperature is 40-60℃ for 15-30 minutes.

3. The surface treatment process for high-performance stainless steel seamless tubes according to claim 1, characterized in that: During the magnetron sputtering process, the vacuum level in the vacuum chamber is 10. -3 -10 -4 Pa uses a titanium target with a purity of 99.9% as the sputtering target material, and introduces a mixture of argon and nitrogen gas. The argon gas flow rate is 50-80 sccm, the nitrogen gas flow rate is 10-20 sccm, the DC voltage of the target material is 300-500V, and the sputtering time is 60-90 minutes.

4. The surface treatment process for high-performance stainless steel seamless tubes according to claim 1, characterized in that: During the chemical vapor deposition growth of silicon carbide coating, methane, silane, and hydrogen are introduced, with a methane flow rate of 20-30 sccm, a silane flow rate of 10-15 sccm, a hydrogen flow rate of 100-150 sccm, a reactor temperature of 1000-1200℃, and a reaction time of 120-180 minutes.

5. The surface treatment process for high-performance stainless steel seamless tubes according to claim 1, characterized in that: When preparing the metal-ceramic buffer layer by plasma spraying, the distance between the spray gun and the pipe surface is 80-100mm, the plasma gas is a mixture of argon and hydrogen, the argon flow rate is 30-50 slpm, the hydrogen flow rate is 5-10 slpm, and the spray gun current is 100-150A.

6. The surface treatment process for high-performance stainless steel seamless tubes according to claim 1, characterized in that: The nano-slow-release antibacterial coating contains silver nanoparticles with a particle size of 20-50 nm and a mass fraction of 1%-3%. It is applied by dip coating and spray coating. During dip coating, the pipe is immersed in the coating for 1-2 minutes. During spray coating, the spray gun pressure is 0.3-0.5 MPa, the spraying distance is 150-200 mm, the curing temperature is 60-80℃, and the curing time is 2-3 hours.

7. The surface treatment process for high-performance stainless steel seamless tubes according to claim 1, characterized in that: The self-healing coating contains micron-sized hollow capsules with an average particle size of 10-20 μm, which are dispersed on the surface of the nano-slow-release antibacterial coating by spin coating. The thickness of the transparent polyurethane protective layer is 30-50 μm.

8. The surface treatment process for high-performance stainless steel seamless tubes according to claim 1, characterized in that: The graphene-metal oxide composite film has a thickness of 100-200 nm and is deposited using magnetron sputtering technology.

9. The surface treatment process for high-performance stainless steel seamless tubes according to claim 1, characterized in that: The fluorinated carbon nanotube coating has a diameter of 5-10 nm and a length of 0.5-1 μm.

10. The surface treatment process for high-performance stainless steel seamless tubes according to claim 1, characterized in that: The environmentally friendly and energy-saving treatment includes: The pickling waste acid solution is treated by ion exchange resin adsorption and membrane filtration for recovery; New energy-saving equipment is used in the magnetron sputtering and chemical vapor deposition processes, and the gas flow ratio is optimized to improve the vacuum level of the equipment.

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