Corrosion-resistant wear-resistant hot-pressing 180-degree elbow and processing technology thereof

Abstract

The invention discloses a corrosion-resistant wear-resistant hot-pressing 180-degree elbow and a processing technology thereof, and relates to the technical field of polymer coatings, and the processing technology comprises the following steps: carrying out sand blasting treatment on an elbow base material, sequentially carrying out ultrasonic cleaning by using acetone, an alkaline degreasing agent and deionized water, spraying an ethanol solution of 5wt% gamma-aminopropyltriethoxysilane on the elbow base material, drying at 80 DEG C for 20-25 minutes, and carrying out vacuum drying to obtain the corrosion-resistant wear-resistant hot-pressing 180-degree elbow. Pre-treated elbows are obtained; and coating the corrosion-resistant and wear-resistant coating on the pretreated elbow, drying at room temperature for 30 minutes, heating to 180 DEG C under the protection of nitrogen, applying pressure of 5 MPa, preserving heat for 2 hours to complete curing, and finally naturally cooling to room temperature to obtain the corrosion-resistant and wear-resistant hot-pressing 180-degree elbow.

Description

Technical Field

[0001] This invention relates to the field of polymer coating technology, specifically to a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow and its processing technology. Background Technology

[0002] During the operation of industrial equipment, elbows, as key components in pipeline systems, are constantly exposed to complex environments of fluid flow, particle erosion, and high-temperature corrosion. Their corrosion and wear resistance directly affects the service life and operating efficiency of the equipment. Due to their structural characteristics, 180-degree elbows, especially under conditions of high fluid velocity and strong particle impact, experience particularly severe erosion and wear on their outer curvature sections.

[0003] Currently, research on corrosion and wear resistance technology for 180-degree elbows mainly focuses on the selection of coating materials and process optimization. Studies have shown that surface treatment using materials such as wear-resistant ceramics and high-temperature corrosion-resistant coatings can effectively improve the corrosion resistance of elbows. However, existing technologies still face many challenges. On the one hand, coatings are prone to peeling during high-temperature or long-term use, leading to a decrease in protective performance; on the other hand, different fluid media and particle characteristics result in different wear mechanisms for coatings, making it difficult to achieve comprehensive adaptation. In addition, controlling the uniformity and adhesion of the coating is difficult, especially under complex working conditions, such as boiler pipelines and oil transportation environments with high requirements, where the durability of the coating still needs further improvement.

[0004] Therefore, it is of great significance to invent a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow to improve the corrosion-resistant and wear-resistant properties of elbows. Summary of the Invention

[0005] The purpose of this invention is to provide a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow and its processing technology to solve the problems raised in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A processing method for a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow includes the following steps: S1: Cut a 10mm thick stainless steel tube blank using a saw, clean the surface with sandblasting, and then spray glass lubricant until the lubricant layer thickness reaches 80-120μm. Dry at room temperature for 30-35 minutes, then place it in a medium-frequency induction heating furnace, set the temperature to 1160-1200℃, and heat in an argon atmosphere for 15-20 minutes to obtain a heat-treated tube blank. Preheat the H13 steel mold to 350-360℃, place the heat-treated tube blank into the mold, and hot press it using a hydraulic press. First, pre-press it under a pressure of 800-1000 tons, and then final press it under a pressure of 1500-1800 tons, holding the pressure for 5 seconds each time, and controlling the extrusion rate at 10-15mm / s. After hot pressing, the hydraulic ejection mechanism demolds the tube blank and transfers it to a slow cooling pit. First, slow cool it to 800℃ under argon protection, and then air cool it to room temperature to obtain the elbow base material. S2: Add silicon carbide and γ-alumina to N-methylpyrrolidone, ultrasonically disperse for 30-35 min, heat to 60-65℃, add γ-aminopropyltriethoxysilane, stir for 1 h, filter under reduced pressure, take the filter material and wash it 3 times with anhydrous ethanol, and vacuum dry at 80-85℃ for 12 h to obtain activated wear-resistant filler. S3: Deionized water, propanol, acetonitrile, and tetraethylammonium hydroxide were placed in a three-necked flask and mixed thoroughly at room temperature. γ-aminopropyltriethoxysilane was slowly added dropwise, and the mixture was stirred vigorously for 10 min. Then, it was magnetically stirred at 60 °C for 24 h. After cooling to room temperature, the product was placed in tetrahydrofuran cooled to 0 °C and placed in a refrigerator until a large amount of white solid precipitated. The mixture was filtered, and the precipitation was repeated three times in tetrahydrofuran. After vacuum drying at 35 °C for 24 h, surface-aminated POSS-NH2 was obtained. Polyether ether ketone was slowly added to concentrated sulfuric acid and stirred for 1 h under ice bath conditions to sulfonate the surface of polyether ether ketone. After the reaction was completed, the mixture was poured into ice water to terminate the reaction. After filtration, it was washed with deionized water until neutral and vacuum dried at 80 °C for 24 h to obtain sulfonated polyether ether ketone. Sulfonated polyether ether ketone was added to N,N-dimethylformamide and stirred until completely dissolved. POSS-NH2 was added, and the mixture was stirred for 6 h and ultrasonically treated for 2 h to obtain modified polyether ether ketone resin solution. S4: Add activated wear-resistant filler, polytetrafluoroethylene ultrafine powder, fumed silica, and modified polyether ether ketone resin liquid to 2,2-bis-(4-glycineoxyphenyl)propane, stir at 60°C for 2 hours, then add methyl hexahydrophthalic anhydride and dibutyltin dilaurate, and continue stirring for 1 hour to obtain an anti-corrosion and wear-resistant coating. S5: The elbow substrate is sandblasted, then ultrasonically cleaned with acetone, alkaline degreaser, and deionized water in sequence. A 5wt% γ-aminopropyltriethoxysilane ethanol solution is sprayed onto it to form a wet film with a thickness of 5-8μm. The film is then placed in a forced-air drying oven at 80℃ for 20-25min to obtain a pre-treated elbow. An anti-corrosion and wear-resistant coating is applied to the pre-treated elbow to form a wet film with a thickness of 180-220μm. After drying at room temperature for 30min, the elbow is placed in an autoclave and heated to 180℃ under nitrogen protection. A pressure of 5MPa is applied and the temperature is maintained for 2 hours to complete the curing. Finally, the elbow is allowed to cool naturally to room temperature to obtain an anti-corrosion and wear-resistant hot-pressed 180° elbow.

[0007] Furthermore, in the activated wear-resistant filler, the proportions of each component by mass are as follows: silicon carbide 40-45 parts, γ-alumina 10-12 parts, N-methylpyrrolidone 300-320 parts, and γ-aminopropyltriethoxysilane 12-14 parts.

[0008] Furthermore, in the POSS-NH2, the proportions of each component by mass are as follows: deionized water 20-25 parts, propanol 7-8 parts, acetonitrile 1.8-2.1 parts, tetraethylammonium hydroxide 0.4-0.6 parts, and γ-aminopropyltriethoxysilane 52-58 parts; in the sulfonated polyether ether ketone, the proportions of each component by mass are as follows: polyether ether ketone 62-68 parts and concentrated sulfuric acid 240-250 parts; in the modified polyether ether ketone resin solution, the proportions of each component by mass are as follows: sulfonated polyether ether ketone 36-40 parts, N,N-dimethylformamide 90-100 parts, and POSS-NH2 9-10 parts.

[0009] Furthermore, in the aforementioned anti-corrosion and wear-resistant coating, the proportions of each component by mass are as follows: 50-55 parts activated wear-resistant filler, 8-10 parts polytetrafluoroethylene ultrafine powder, 5-6 parts fumed silica, 125-135 parts modified polyetheretherketone resin liquid, 15-18 parts 2,2-bis-(4-glycyloxyphenyl)propane, 5-6 parts methylhexahydrophthalic anhydride, and 0.9-1.1 parts dibutyltin dilaurate.

[0010] Compared with the prior art, the beneficial effects of the present invention are: During heat treatment of the tube blank, a glass lubricant with a thickness of 80~120μm is pre-sprayed. This lubricant melts at a high temperature of 1160~1200℃ to form a protective film, reducing oxidation on the tube blank surface. It also reduces the friction coefficient between the metal and the mold during hot pressing, avoiding surface carbon loss and microcracks, and improving the density of the substrate. Gradient pressure hot pressing is used when preparing the elbow substrate. The pre-pressing stage allows the material to initially flow plastically, reducing internal stress concentration during final pressing. The high pressure of the final pressing ensures that the curved parts of the elbow are fully filled, avoiding uneven wall thickness. Finally, the elbow substrate is slowly cooled to 800℃ under argon protection to suppress the martensitic phase transformation and reduce residual stress. Then, it is air-cooled to room temperature to produce fine-grained ferrite and a small amount of pearlite structure, giving the elbow substrate both impact resistance and basic wear resistance.

[0011] The POSS nanoscale cage structure of POSS-NH2 prepared in this invention serves as a rigid nanofiller, uniformly dispersed in the resin to form physical cross-linking points, hindering molecular chain movement and improving the tensile strength and heat distortion temperature of the resin. After polyether ether ketone is sulfonated with concentrated sulfuric acid, sulfonic acid groups are introduced onto the benzene ring. As polar groups, the sulfonic acid groups form hydrogen bonds with the amino groups of POSS-NH2 and have chemical affinity with the silane-modified layer on the filler surface, improving the compatibility between the resin and the filler. At the same time, the sulfonic acid groups enable the resin to form stronger physical adsorption and chemical interaction with the hydroxyl groups on the surface of the metal substrate, thereby improving the adhesion between the coating and the elbow substrate.

[0012] In the corrosion-resistant and wear-resistant coating prepared in this invention, the polytetrafluoroethylene (PTFE) ultrafine powder has a layered molecular structure, which easily slips during friction to form a lubricating film, reducing the surface friction coefficient of the coating and reducing the cutting effect of abrasive particles on the coating. Meanwhile, nano-sized fumed silica fills the pores of the coating, forming a "skeleton structure" that improves the coating's hardness and scratch resistance, while also hindering the penetration path of corrosive media. Together with PTFE, it achieves the dual effect of "friction reduction + wear resistance". 2,2-bis-(4-glycyloxyphenyl)propane can synergistically enhance the coating performance with the modified polyetheretherketone (PEEK) resin liquid. The polar sulfonic acid groups of PEEK form hydrogen bonds with the polar groups of epoxy resin, and the amino groups of POSS-NH2 undergo partial cross-linking reactions with the epoxy groups of epoxy resin, enhancing the integrity of the resin phase. At this time, the high cross-linking density of epoxy resin provides rigid support, while the high-temperature resistant segments of PEEK and the nano-reinforcing effect of POSS improve the thermal stability and deformation resistance of the coating.

[0013] In this invention, the elbow substrate is pretreated by sandblasting to create a micro-uneven structure on the substrate surface, increasing the specific surface area and providing mechanical interlocking points for the coating, thus improving adhesion. Simultaneously, after drying, a 5wt% γ-aminopropyltriethoxysilane ethanol solution reacts with the metal oxide on the elbow substrate surface at one end to form a Si-O-Me covalent bond, while the amino group at the other end reacts with the coating to form a "metal-silane-resin" chemical bridge, fundamentally solving the problem of weak interfacial bonding between the metal and organic coating. The pretreated elbow is then cured at 5MPa pressure. The external pressure forces the solvent in the coating to evaporate more thoroughly, promoting the full diffusion of resin molecular chains to fill the gaps between fillers, eliminating pores, and forming a defect-free, dense structure. This reduces the penetration channels of corrosive media. Nitrogen gas protection prevents oxidative degradation of the resin matrix during high-temperature curing, ensuring the integrity of the coating's chemical structure and maintaining its mechanical properties and corrosion resistance. Detailed Implementation

[0014] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] In the following examples, polyetheretherketone (PEEK), Mv=35000, CAS29658-26-2; polytetrafluoroethylene (PTFE) ultrafine powder, particle size less than 1μm, CAS9002-84-0; fumed silica, particle size 40-50nm, CAS112945-52-5; and other raw materials were commercially available.

[0016] Example 1: A processing technology for a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow: S1: A stainless steel tube blank with a wall thickness of 10mm is cut with a saw, the surface is cleaned by sandblasting, and then a glass lubricant is sprayed until the lubricant layer thickness reaches 80μm. It is dried at room temperature for 30 minutes, placed in a medium-frequency induction heating furnace, and heated in an argon environment for 15 minutes to obtain a heat-treated tube blank; the H13 steel mold is preheated to 350℃, the heat-treated tube blank is placed in the mold, and hot-pressed using a hydraulic press. It is first pre-pressed under a pressure of 800 tons, and then finally pressed under a pressure of 1500 tons, with each pressure holding for 5 seconds, and the extrusion rate is controlled at 10mm / s. After hot pressing, the hydraulic ejection mechanism demolds the tube blank and transfers it to a slow cooling pit. It is first slowly cooled to 800℃ under argon protection and then air-cooled to room temperature to obtain the elbow base material; S2: Add 40 parts silicon carbide and 10 parts γ-alumina to 300 parts N-methylpyrrolidone, ultrasonically disperse for 30 min, heat to 60℃, add 12 parts γ-aminopropyltriethoxysilane, stir at 2000 rpm for 1 h, filter under reduced pressure, take the filter material and wash it 3 times with anhydrous ethanol, and vacuum dry at 80℃ for 12 h to obtain activated wear-resistant filler; S3: 20 parts deionized water, 7 parts propanol, 1.8 parts acetonitrile, and 0.4 parts tetraethylammonium hydroxide were placed in a three-necked flask and mixed thoroughly at room temperature. 52 parts γ-aminopropyltriethoxysilane were slowly added dropwise, and the mixture was stirred vigorously for 10 minutes. Then, it was magnetically stirred at 60°C for 24 hours. After cooling to room temperature, the product was placed in tetrahydrofuran cooled to 0°C and placed in a refrigerator until a large amount of white solid precipitated. The mixture was filtered, and the precipitation was repeated three times in tetrahydrofuran. Finally, it was vacuum dried at 35°C for 24 hours to obtain surface-aminated POSS-NH. 2. Slowly add 62 parts of polyether ether ketone to 240 parts of concentrated sulfuric acid and stir for 1 hour under ice bath conditions to sulfonate the surface of polyether ether ketone. After the reaction is complete, pour the mixture into ice water to terminate the reaction. After filtration, wash with deionized water until neutral and dry under vacuum at 80°C for 24 hours to obtain sulfonated polyether ether ketone. Add 36 parts of sulfonated polyether ether ketone to 93 parts of N,N-dimethylformamide and stir until completely dissolved. Add 9 parts of POSS-NH2 and continue stirring for 6 hours. Then sonicate for 2 hours to obtain modified polyether ether ketone resin solution. S4: Add 50 parts of activated wear-resistant filler, 8 parts of polytetrafluoroethylene ultrafine powder, 5 parts of fumed silica, and 125 parts of modified polyether ether ketone resin liquid to 15 parts of 2,2-bis-(4-glycineoxyphenyl)propane, stir at 60°C for 2 hours, then add 5 parts of methyl hexahydrophthalic anhydride and 0.9 parts of dibutyltin dilaurate, and continue stirring for 1 hour to obtain an anti-corrosion and wear-resistant coating. S5: The elbow substrate is sandblasted, then ultrasonically cleaned with acetone, alkaline degreaser, and deionized water in sequence. A 5wt% γ-aminopropyltriethoxysilane ethanol solution is sprayed onto it to form a 5μm thick wet film. The film is then placed in a forced-air oven and dried at 80℃ for 20 minutes to obtain a pre-treated elbow. An anti-corrosion and wear-resistant coating is applied to the pre-treated elbow to form a 180μm thick wet film. After drying at room temperature for 30 minutes, the film is placed in an autoclave and heated to 180℃ under nitrogen protection. A pressure of 5MPa is applied and the film is kept at that temperature for 2 hours to complete the curing. Finally, the film is allowed to cool naturally to room temperature to obtain an anti-corrosion and wear-resistant hot-pressed 180-degree elbow.

[0017] Example 2: A processing technology for a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow: S1: A stainless steel tube blank with a wall thickness of 10mm is cut with a saw, the surface is cleaned by sandblasting, and then a glass lubricant is sprayed until the lubricant layer thickness reaches 94μm. It is dried at room temperature for 32 minutes and placed in a medium-frequency induction heating furnace. The temperature is set at 1170℃ and heated in an argon environment for 16 minutes to obtain a heat-treated tube blank. The H13 steel mold is preheated to 353℃, the heat-treated tube blank is placed in the mold, and hot-pressed using a hydraulic press. It is first pre-pressed under a pressure of 870 tons and then finally pressed under a pressure of 1600 tons, with each pressure holding for 5 seconds. The extrusion rate is controlled at 10mm / s. After hot pressing, the hydraulic ejection mechanism demolds the tube blank and transfers it to a slow cooling pit. It is first slowly cooled to 800℃ under argon protection and then air-cooled to room temperature to obtain the elbow base material. S2: Add 42 parts silicon carbide and 11 parts γ-alumina to 300 parts N-methylpyrrolidone, ultrasonically disperse for 30 min, heat to 62℃, add 13 parts γ-aminopropyltriethoxysilane, stir at 2000 rpm for 1 h, filter under reduced pressure, wash the filter with anhydrous ethanol 3 times, and vacuum dry at 81℃ for 12 h to obtain activated wear-resistant filler. S3: 22 parts deionized water, 7 parts propanol, 1.9 parts acetonitrile, and 0.5 parts tetraethylammonium hydroxide were placed in a three-necked flask and mixed thoroughly at room temperature. 54 parts γ-aminopropyltriethoxysilane were slowly added dropwise, and the mixture was stirred vigorously for 10 minutes. Then, it was magnetically stirred at 60°C for 24 hours. After cooling to room temperature, the product was placed in tetrahydrofuran cooled to 0°C and placed in a refrigerator until a large amount of white solid precipitated. The mixture was filtered, and the precipitation was repeated three times in tetrahydrofuran. Finally, it was vacuum dried at 35°C for 24 hours to obtain surface-aminated POSS-NH. 2. Slowly add 65 parts of polyether ether ketone to 245 parts of concentrated sulfuric acid and stir for 1 hour under ice bath conditions to sulfonate the surface of polyether ether ketone. After the reaction is complete, pour the mixture into ice water to terminate the reaction. After filtration, wash with deionized water until neutral and dry under vacuum at 80°C for 24 hours to obtain sulfonated polyether ether ketone. Add 37 parts of sulfonated polyether ether ketone to 96 parts of N,N-dimethylformamide and stir until completely dissolved. Add 9 parts of POSS-NH2 and continue stirring for 6 hours. Then sonicate for 2 hours to obtain modified polyether ether ketone resin solution. S4: Add 51 parts of activated wear-resistant filler, 9 parts of polytetrafluoroethylene ultrafine powder, 5 parts of fumed silica, and 128 parts of modified polyether ether ketone resin liquid to 16 parts of 2,2-bis-(4-glycineoxyphenyl)propane, stir at 60°C for 2 hours, then add 5 parts of methyl hexahydrophthalic anhydride and 0.9 parts of dibutyltin dilaurate, and continue stirring for 1 hour to obtain an anti-corrosion and wear-resistant coating. S5: The elbow substrate is sandblasted, then ultrasonically cleaned with acetone, alkaline degreaser, and deionized water in sequence. A 5wt% γ-aminopropyltriethoxysilane ethanol solution is sprayed onto it to form a 5μm thick wet film. The film is then placed in a forced-air oven and dried at 80℃ for 20 minutes to obtain a pre-treated elbow. An anti-corrosion and wear-resistant coating is applied to the pre-treated elbow to form a 180μm thick wet film. After drying at room temperature for 30 minutes, the film is placed in an autoclave and heated to 180℃ under nitrogen protection. A pressure of 5MPa is applied and the film is kept at that temperature for 2 hours to complete the curing. Finally, the film is allowed to cool naturally to room temperature to obtain an anti-corrosion and wear-resistant hot-pressed 180-degree elbow.

[0018] Example 3: A processing technology for a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow: S1: A stainless steel tube blank with a wall thickness of 10mm is cut with a saw, the surface is cleaned by sandblasting, and then a glass lubricant is sprayed until the lubricant layer thickness reaches 105μm. It is dried at room temperature for 34 minutes, placed in a medium-frequency induction heating furnace, and heated in an argon environment for 18 minutes to obtain a heat-treated tube blank; the H13 steel mold is preheated to 357℃, the heat-treated tube blank is placed in the mold, and hot-pressed using a hydraulic press. It is first pre-pressed under a pressure of 940 tons, and then finally pressed under a pressure of 1700 tons, with each pressure holding for 5 seconds, and the extrusion rate is controlled at 14mm / s. After hot pressing, the hydraulic ejection mechanism demolds the tube blank and transfers it to a slow cooling pit. It is first slowly cooled to 800℃ under argon protection and then air-cooled to room temperature to obtain the elbow base material; S2: Add 44 parts silicon carbide and 12 parts γ-alumina to 320 parts N-methylpyrrolidone, ultrasonically disperse for 32 min, heat to 65℃, add 14 parts γ-aminopropyltriethoxysilane, stir at 2000 rpm for 1 h, filter under reduced pressure, wash the filter with anhydrous ethanol 3 times, and vacuum dry at 85℃ for 12 h to obtain activated wear-resistant filler; S3: 23 parts deionized water, 7 parts propanol, 2 parts acetonitrile, and 0.6 parts tetraethylammonium hydroxide were placed in a three-necked flask and mixed thoroughly at room temperature. 55 parts γ-aminopropyltriethoxysilane were slowly added dropwise, and the mixture was stirred vigorously for 10 min. Then, it was magnetically stirred at 60 °C for 24 h. After cooling to room temperature, the product was placed in tetrahydrofuran cooled to 0 °C and placed in a refrigerator until a large amount of white solid precipitated. The mixture was filtered, and the precipitation was repeated three times in tetrahydrofuran. After vacuum drying at 35 °C for 24 h, surface-aminated POSS-NH2 was obtained. 67 parts of polyether ether ketone were slowly added to 248 parts of concentrated sulfuric acid and stirred for 1 hour under ice bath conditions to sulfonate the surface of polyether ether ketone. After the reaction was completed, the mixture was poured into ice water to terminate the reaction. After filtration, it was washed with deionized water until neutral and dried under vacuum at 80°C for 24 hours to obtain sulfonated polyether ether ketone. 40 parts of sulfonated polyether ether ketone were added to 96 parts of N,N-dimethylformamide and stirred until completely dissolved. 10 parts of POSS-NH2 were added and stirred for another 6 hours. The mixture was then sonicated for 2 hours to obtain modified polyether ether ketone resin solution. S4: Add 54 parts of activated wear-resistant filler, 10 parts of polytetrafluoroethylene ultrafine powder, 5 parts of fumed silica, and 131 parts of modified polyetheretherketone resin liquid to 18 parts of 2,2-bis-(4-glycineoxyphenyl)propane, stir at 60°C for 2 hours, then add 5 parts of methylhexahydrophthalic anhydride and 1.1 parts of dibutyltin dilaurate, and continue stirring for 1 hour to obtain an anti-corrosion and wear-resistant coating. S5: The elbow substrate is sandblasted, then ultrasonically cleaned with acetone, alkaline degreaser, and deionized water in sequence. A 5wt% γ-aminopropyltriethoxysilane ethanol solution is sprayed onto it to form a 5μm thick wet film. The film is then placed in a forced-air oven and dried at 80℃ for 20 minutes to obtain a pre-treated elbow. An anti-corrosion and wear-resistant coating is applied to the pre-treated elbow to form a 180μm thick wet film. After drying at room temperature for 30 minutes, the film is placed in an autoclave and heated to 180℃ under nitrogen protection. A pressure of 5MPa is applied and the film is kept at that temperature for 2 hours to complete the curing. Finally, the film is allowed to cool naturally to room temperature to obtain an anti-corrosion and wear-resistant hot-pressed 180-degree elbow.

[0019] Example 4: A processing technology for a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow: S1: A stainless steel tube blank with a wall thickness of 10mm is cut with a saw, the surface is cleaned by sandblasting, and then a glass lubricant is sprayed until the lubricant layer thickness reaches 120μm. It is dried at room temperature for 35 minutes, placed in a medium-frequency induction heating furnace, and heated in an argon environment for 20 minutes to obtain a heat-treated tube blank; the H13 steel mold is preheated to 360℃, the heat-treated tube blank is placed in the mold, and hot-pressed using a hydraulic press. It is first pre-pressed under a pressure of 1000 tons, and then finally pressed under a pressure of 1800 tons, with each pressure holding for 5 seconds, and the extrusion rate is controlled at 15mm / s. After hot pressing, the hydraulic ejection mechanism demolds the tube blank and transfers it to a slow cooling pit. It is first slowly cooled to 800℃ under argon protection and then air-cooled to room temperature to obtain the elbow base material; S2: Add 45 parts silicon carbide and 12 parts γ-alumina to 320 parts N-methylpyrrolidone, ultrasonically disperse for 35 min, heat to 65℃, add 14 parts γ-aminopropyltriethoxysilane, stir at 2000 rpm for 1 h, filter under reduced pressure, wash the filter with anhydrous ethanol 3 times, and vacuum dry at 85℃ for 12 h to obtain activated wear-resistant filler. S3: 25 parts deionized water, 8 parts propanol, 2.1 parts acetonitrile, and 0.6 parts tetraethylammonium hydroxide were placed in a three-necked flask and mixed thoroughly at room temperature. 58 parts γ-aminopropyltriethoxysilane were slowly added dropwise, and the mixture was stirred vigorously for 10 minutes. Then, it was magnetically stirred at 60°C for 24 hours. After cooling to room temperature, the product was placed in tetrahydrofuran cooled to 0°C and placed in a refrigerator until a large amount of white solid precipitated. The mixture was filtered, and the precipitation was repeated three times in tetrahydrofuran. Finally, it was vacuum dried at 35°C for 24 hours to obtain surface-aminated POSS-NH2. 68 parts of polyether ether ketone were slowly added to 250 parts of concentrated sulfuric acid and stirred for 1 hour under ice bath conditions to sulfonate the surface of polyether ether ketone. After the reaction was completed, the mixture was poured into ice water to terminate the reaction. After filtration, it was washed with deionized water until neutral and dried under vacuum at 80°C for 24 hours to obtain sulfonated polyether ether ketone. 40 parts of sulfonated polyether ether ketone were added to 100 parts of N,N-dimethylformamide and stirred until completely dissolved. 10 parts of POSS-NH2 were added and stirred for another 6 hours. The mixture was then sonicated for 2 hours to obtain modified polyether ether ketone resin solution. S4: Add 55 parts of activated wear-resistant filler, 10 parts of polytetrafluoroethylene ultrafine powder, 6 parts of fumed silica, and 135 parts of modified polyetheretherketone resin liquid to 18 parts of 2,2-bis-(4-glycineoxyphenyl)propane, stir at 60°C for 2 hours, then add 6 parts of methylhexahydrophthalic anhydride and 1.1 parts of dibutyltin dilaurate, and continue stirring for 1 hour to obtain an anti-corrosion and wear-resistant coating. S5: The elbow substrate is sandblasted, then ultrasonically cleaned with acetone, alkaline degreaser, and deionized water in sequence. A 5wt% γ-aminopropyltriethoxysilane ethanol solution is sprayed onto it to form a 5μm thick wet film. The film is then placed in a forced-air oven and dried at 80℃ for 20 minutes to obtain a pre-treated elbow. An anti-corrosion and wear-resistant coating is applied to the pre-treated elbow to form a 180μm thick wet film. After drying at room temperature for 30 minutes, the film is placed in an autoclave and heated to 180℃ under nitrogen protection. A pressure of 5MPa is applied and the film is kept at that temperature for 2 hours to complete the curing. Finally, the film is allowed to cool naturally to room temperature to obtain an anti-corrosion and wear-resistant hot-pressed 180-degree elbow.

[0020] Comparative Example 1: A processing technology for a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow: S2: 40 parts of silicon carbide and 10 parts of γ-alumina were added to 300 parts of N-methylpyrrolidone, ultrasonically dispersed for 30 min, heated to 60℃, stirred at 2000 rpm for 1 h, filtered under reduced pressure, the filter material was washed 3 times with anhydrous ethanol, and vacuum dried at 80℃ for 12 h to obtain activated wear-resistant filler; The remaining steps are the same as in Example 1.

[0021] Comparative Example 2: A processing technology for a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow: S4: 50 parts of activated wear-resistant filler, 8 parts of polytetrafluoroethylene ultrafine powder, 5 parts of fumed silica, and 125 parts of modified polyether ether ketone resin liquid are stirred at 60°C for 2 hours, then 5 parts of methyl hexahydrophthalic anhydride and 0.9 parts of dibutyltin dilaurate are added, and stirring is continued for 1 hour to obtain a corrosion-resistant and wear-resistant coating; The remaining steps are the same as in Example 1.

[0022] Comparative Example 3: A processing technology for a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow: S5: The elbow substrate is sandblasted and then ultrasonically cleaned with acetone, alkaline degreasing agent, and deionized water in sequence to obtain a pre-treated elbow; the corrosion-resistant and wear-resistant coating is applied to the pre-treated elbow to form a wet film with a thickness of 180μm. After drying at room temperature for 30 minutes, it is placed in a hot autoclave, heated to 180℃ under nitrogen protection, pressure of 5MPa is applied, and the temperature is maintained for 2 hours to complete the curing. Finally, it is naturally cooled to room temperature to obtain a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow.

[0023] The remaining steps are the same as in Example 1.

[0024] Experiment: The wear resistance of the elbow was tested according to GB / T 9286-2021 standard.

[0025] The corrosion resistance of the elbow was tested according to GB / T 4334-2020 standard.

[0026]

[0027] Conclusion: The corrosion-resistant and wear-resistant hot-pressed 180-degree elbow prepared by this invention has excellent wear-resistant and corrosion-resistant properties.

[0028] In Comparative Example 1, the absence of γ-aminopropyltriethoxysilane in the preparation of the active wear-resistant material reduced the active sites for subsequent reactions with the resin, increasing the compatibility issues between the inorganic filler and the organic resin, resulting in a coating that was not wear-resistant, easily peeled off, and not corrosion-resistant. In Comparative Example 2, the absence of 2,2-bis-(4-glycyloxyphenyl)propane in the preparation of the modified polyetheretherketone resin solution prevented the use of the high crosslinking density of the epoxy resin to provide rigid support, resulting in a coating that was not wear-resistant and had weak corrosion resistance. In Comparative Example 3, the absence of spraying a 5wt% γ-aminopropyltriethoxysilane ethanol solution onto the elbow substrate during pretreatment resulted in a weak interfacial bond between the metal and the organic coating, leading to a coating that was not wear-resistant and not corrosion-resistant.

[0029] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A processing method for a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow, characterized in that: Includes the following steps: The elbow substrate is sandblasted, then ultrasonically cleaned with acetone, alkaline degreaser, and deionized water in sequence. A 5wt% γ-aminopropyltriethoxysilane ethanol solution is sprayed onto it, and it is dried at 80℃ for 20-25 minutes to obtain a pre-treated elbow. The anti-corrosion and wear-resistant coating is applied to the pre-treated elbow, and after drying at room temperature for 30 minutes, it is heated to 180℃ under nitrogen protection, a pressure of 5MPa is applied, and it is kept at this temperature for 2 hours to complete the curing. Finally, it is naturally cooled to room temperature to obtain an anti-corrosion and wear-resistant hot-pressed 180-degree elbow.

2. The processing technology of a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow according to claim 1, characterized in that: The method for preparing the corrosion-resistant and wear-resistant coating includes the following steps: Activated wear-resistant filler, polytetrafluoroethylene ultrafine powder, fumed silica, and modified polyether ether ketone resin liquid were added to 2,2-bis-(4-glycineoxyphenyl)propane and stirred at 60°C for 2 hours. Then, methyl hexahydrophthalic anhydride and dibutyltin dilaurate were added, and stirring was continued for 1 hour to obtain an anti-corrosion and wear-resistant coating.

3. The processing technology of a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow according to claim 2, characterized in that: The corrosion-resistant and wear-resistant coating comprises the following components by mass: 50-55 parts activated wear-resistant filler, 8-10 parts polytetrafluoroethylene ultrafine powder, 5-6 parts fumed silica, 125-135 parts modified polyetheretherketone resin liquid, 15-18 parts 2,2-bis-(4-glycyloxyphenyl)propane, 5-6 parts methylhexahydrophthalic anhydride, and 0.9-1.1 parts dibutyltin dilaurate.

4. The processing technology of a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow according to claim 2, characterized in that: The preparation method of the modified polyetheretherketone resin liquid includes the following steps: Deionized water, propanol, acetonitrile, and tetraethylammonium hydroxide were placed in a reaction vessel and mixed thoroughly at room temperature. γ-aminopropyltriethoxysilane was added dropwise, and the mixture was stirred vigorously for 10 min, then magnetically stirred at 60 °C for 24 h. After cooling to room temperature, the product was placed in tetrahydrofuran cooled to 0 °C, filtered, and vacuum dried to obtain surface-aminated POSS-NH2. Polyether ether ketone was added to concentrated sulfuric acid and stirred in an ice bath for 1 hour. After the reaction was completed, the mixture was poured into ice water to terminate the reaction. After filtration, it was washed with deionized water until neutral and vacuum dried at 80 °C for 24 h to obtain sulfonated polyether ether ketone. Sulfonated polyether ether ketone was added to N,N-dimethylformamide and stirred until completely dissolved. POSS-NH2 was added, and stirring was continued for 6 hours. The mixture was then sonicated for 2 hours to obtain modified polyether ether ketone resin solution.

5. The processing technology of a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow according to claim 4, characterized in that: In the POSS-NH2, the components, by mass parts, are: 20-25 parts deionized water, 7-8 parts propanol, 1.8-2.1 parts acetonitrile, 0.4-0.6 parts tetraethylammonium hydroxide, and 52-58 parts γ-aminopropyltriethoxysilane; in the sulfonated polyether ether ketone, the components, by mass parts, are: 62-68 parts polyether ether ketone and 240-250 parts concentrated sulfuric acid; in the modified polyether ether ketone resin solution, the components, by mass parts, are: 36-40 parts sulfonated polyether ether ketone, 90-100 parts N,N-dimethylformamide, and 9-10 parts POSS-NH2.

6. The processing technology of a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow according to claim 2, characterized in that: The method for preparing the activated wear-resistant filler includes the following steps: Silicon carbide and γ-alumina were added to N-methylpyrrolidone and ultrasonically dispersed for 30-35 min. The temperature was raised to 60-65℃, γ-aminopropyltriethoxysilane was added, and the mixture was stirred for 1 h. The mixture was then filtered under reduced pressure, and the filtered material was washed three times with anhydrous ethanol and vacuum dried at 80-85℃ for 12 h to obtain the activated wear-resistant filler.

7. The processing technology of a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow according to claim 6, characterized in that: In the activated wear-resistant filler, the proportions of each component by mass are as follows: silicon carbide 40-45 parts, γ-alumina 10-12 parts, N-methylpyrrolidone 300-320 parts, and γ-aminopropyltriethoxysilane 12-14 parts.

8. The processing technology of a corrosion-resistant and wear-resistant hot-pressed 180-degree elbow according to claim 1, characterized in that: The method for preparing the elbow substrate includes the following steps: Stainless steel tube blanks are cut and cleaned by sandblasting, then coated with glass lubricant and dried at room temperature for 30–35 minutes. They are then heated at 1160–1200℃ in an argon atmosphere for 15–20 minutes to obtain heat-treated tube blanks. The mold is preheated to 350–360℃, and the heat-treated tube blanks are placed in the mold and hydraulically formed. The blanks are pre-pressed and then finally pressed, with each press lasting 5 seconds. The extrusion rate is controlled at 10–15 mm / s. After the extrusion is completed, the blanks are demolded by a hydraulic ejection mechanism and transferred to a slow cooling pit. The blanks are first slowly cooled to 800℃ under argon protection and then air-cooled to room temperature to obtain elbow base materials.

9. The corrosion-resistant and wear-resistant hot-pressed 180-degree elbow prepared by the processing technology of any one of claims 1-8.

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