A nickel-tungsten alloy plating for a perforated liner and a process for producing the same

Abstract

The application relates to the technical field of alloy plating, and particularly discloses a nickel-tungsten alloy plating layer for a perforated liner pipe and a preparation process thereof. The preparation process of the nickel-tungsten alloy plating layer for the perforated liner pipe comprises the following steps: S1, pretreatment: firstly, degreasing treatment is performed on the perforated liner pipe by adopting a channel degreasing solution, and then activation treatment is performed on the perforated liner pipe by adopting a channel activation solution; S2, plating: the pretreated perforated liner pipe is placed in a nickel-tungsten chemical plating solution to perform chemical plating and form a nickel-tungsten alloy plating layer; S3, post-treatment: the plated perforated liner pipe is immersed in an acidic passivation solution for passivation treatment; then, ultrasonic impact is performed; and then, the perforated liner pipe is placed in a nano-composite hole sealing solution for immersion and hole sealing treatment. The preparation process of the nickel-tungsten alloy plating layer significantly improves the durability and anti-falling performance of the nickel-tungsten alloy plating layer of the perforated liner pipe through the synergistic effect of multiple steps.

Description

TECHNICAL FIELD

[0001] The application relates to the alloy plating technology field, in particular to a nickel-tungsten alloy plating layer for a perforated liner pipe and a preparation process thereof. BACKGROUND

[0002] The perforated liner pipe is applied to the fields of petroleum and chemical fluid conveying and precise hydraulic systems, and the inner wall and the hole surface thereof need to withstand medium corrosion, particle scouring and periodic pressure fluctuation, so that the corrosion resistance, wear resistance and bonding force with the base body of the surface plating layer have strict requirements. The nickel-tungsten alloy plating layer becomes one of the preferred solutions for the surface reinforcement of the perforated liner pipe due to high hardness, excellent chemical stability and low friction coefficient, but the performance thereof needs to be adapted to the special geometry of the perforated structure, otherwise problems such as hole blockage of the liner pipe, local rapid wear or plating layer falling off are easily caused.

[0003] In the related art, a patent document with the announcement number CN118814104B discloses an anti-hydrogen sulfide and anti-carbon dioxide nickel-tungsten plating layer corrosion-resistant oil jacket pipe for marine use and a preparation method thereof. The anti-hydrogen sulfide and anti-carbon dioxide nickel-tungsten plating layer corrosion-resistant oil jacket pipe for marine use in the technical solution comprises a carbon steel pipe base body, an inner corrosion-resistant coating and an outer corrosion-resistant coating, wherein the inner and outer corrosion-resistant coatings both comprise a nickel-tungsten plating layer, an intermediate layer and a hybrid layer. The preparation method of the anti-hydrogen sulfide and anti-carbon dioxide nickel-tungsten plating layer corrosion-resistant oil jacket pipe for marine use in the application comprises the following steps: firstly, the carbon steel pipe base body is pretreated by cleaning, rust removal and the like, and then a nickel-tungsten plating layer is coated; then the surface of the nickel-tungsten plating layer is uniformly coated with an intermediate layer coating; and finally, the surface of the intermediate layer is uniformly coated with a hybrid layer coating. The anti-hydrogen sulfide and anti-carbon dioxide nickel-tungsten plating layer corrosion-resistant oil jacket pipe for marine use prepared by the above method has excellent temperature resistance and wear resistance.

[0004] However, when the above nickel-tungsten plating layer is applied to the perforated liner pipe, the plating layer has the problems of insufficient durability and easy falling off in the application. The reason is that the multi-layer coating of the hole longitudinal depth area and the hole edge is difficult to closely adhere, and under the long-term action of medium scouring and pressure fluctuation, the coating is easy to peel off from the surface of the liner pipe. After the plating layer falls off, the inner wall of the liner pipe is directly exposed to the corrosion medium and particle scouring environment, which not only accelerates the wear of the liner pipe body, but also may cause the hole to be blocked by the falling-off coating debris, resulting in the failure of the core functions of the perforated liner pipe such as fluid distribution and pressure stability, and unable to meet the long-term stable service requirements of the perforated liner pipe in the fields of petroleum and chemical fluid conveying and precise hydraulic systems. SUMMARY

[0005] In order to solve the problems of insufficient durability and easy falling off of the nickel-tungsten plating layer, the application provides a nickel-tungsten alloy plating layer for a perforated liner pipe and a preparation process thereof.

[0006] The preparation process of the nickel-tungsten alloy plating layer for the perforated liner pipe provided by the application adopts the following technical solution:

[0007] A process for preparing a nickel-tungsten alloy coating for a perforated liner includes the following steps:

[0008] S1. Pretreatment: First, the perforated liner is degreased with a pore degreasing solution, and then the perforated liner is activated with a pore activation solution.

[0009] S2. Plating: The pretreated perforated liner is placed in a nickel-tungsten electroless plating solution and electroless plating is performed at 80-90℃ to form a nickel-tungsten alloy coating. The nickel-tungsten electroless plating solution includes the following components: nickel sulfate 28-35g / L, sodium tungstate 10-15g / L, composite complexing agent 38-55g / L, composite reducing agent 20-32g / L, hexadecyltrimethylammonium bromide 1.2-2g / L, and modified nano-tungsten carbide particles 0.8-1.5g / L.

[0010] S3. Post-treatment: Immerse the plated perforated liner in an acidic passivation solution and keep it at 40-50℃ for 15-25 minutes; then use a columnar ultrasonic probe to ultrasonically impact the coating in the channel and the transition area of ​​the hole edge; finally, place the perforated liner in a nano-composite sealing solution for sealing treatment.

[0011] By adopting the above technical solutions, in the pretreatment stage, the degreasing solution effectively removes oil and impurities from the surface of the liner and inside the channels, providing a clean substrate for coating adhesion; the activating solution enhances the surface activity of the substrate, promoting a tight bond between the coating and the substrate. In the plating stage, the components in the nickel-tungsten electroless plating solution work synergistically: nickel sulfate and sodium tungstate provide the source of metal ions, the composite complexing agent stabilizes the metal ion concentration, ensuring uniform deposition of the coating; the composite reducing agent promotes the reduction of metal ions to metal, forming a dense coating; hexadecyltrimethylammonium bromide improves the dispersibility of the plating solution, and modified nano-tungsten carbide particles enhance the hardness and wear resistance of the coating. The combined effect of multiple factors results in a tight coating structure and a strong bond. In the post-treatment stage, the acidic passivation solution forms a protective film to prevent oxidation and corrosion of the coating; ultrasonic impact eliminates internal stress in the coating, enhancing the adhesion between the coating and the substrate; the nano-composite sealing solution fills the pores of the coating, preventing the intrusion of corrosive media, comprehensively improving the durability of the coating and effectively preventing peeling. The preparation process of the nickel-tungsten alloy coating in this application significantly improves the durability and anti-peeling performance of the nickel-tungsten alloy coating for perforated liner tubes through the synergistic effect of multiple steps.

[0012] Optionally, in S1, the pore degreasing solution includes the following components:

[0013] Sodium hydroxide 18-25 g / L, sodium carbonate 12-18 g / L, sodium silicate 6-12 g / L, disodium EDTA 2-4 g / L, and fatty alcohol polyoxyethylene ether 0.8-1.5 g / L.

[0014] By employing the above technical solution, the main degreasing agents sodium hydroxide and sodium carbonate effectively remove oil stains, while sodium silicate forms a protective film to aid degreasing. The core innovation lies in the combination of disodium EDTA and fatty alcohol polyoxyethylene ether. Disodium EDTA can chelate residual metallic impurities on the liner surface, preventing impurities from forming an isolation layer between the coating and the substrate, and preventing the coating from growing around impurities to form loosely bonded areas. Fatty alcohol polyoxyethylene ether, as a nonionic surfactant, reduces the surface tension of the degreasing solution, allowing it to penetrate deep into the pores, ensuring no oil residue remains within the pores, further reducing the risk of coating peeling, and providing a good foundation for subsequent coating deposition.

[0015] Optionally, in S1, the degreasing treatment method is as follows: the perforated liner is completely immersed in the degreasing solution in the pores, and the degreasing solution is continuously pumped into the pores of the liner using a peristaltic pump at a flow rate of 1-2 mL / min, the degreasing temperature is controlled at 55-65℃, and the degreasing time is 25-35 min; after degreasing, the residual degreasing solution in the pores is first blown out with compressed air, and then the pores are backwashed with deionized water for 1-2 min.

[0016] By adopting the above technical solution, the peristaltic pump continuously pumps degreasing solution during the degreasing process, replacing the aged degreasing solution in the channels and preventing deep-seated oil stains from being unable to be removed due to degreasing solution failure. Backwashing allows water to enter from one end of the channel and exit from the other, thoroughly rinsing away residual degreasing solution and oil debris. This prevents residual degreasing solution from reacting with the substrate during subsequent activation and plating processes, thus protecting the coating interface and effectively ensuring the adhesion between the coating and the substrate, reducing the possibility of coating peeling.

[0017] Optionally, in S1, the pore activation solution includes the following components:

[0018] Hydrochloric acid 22-30 mL / L, hydrofluoric acid 6-10 mL / L, citric acid 12-18 g / L and urotropine 1.5-3 g / L.

[0019] By employing the above technical solutions, hydrochloric acid and hydrofluoric acid can rapidly dissolve the oxide film on the liner surface, exposing a fresh metal surface and enhancing the liner's chemical activity. Citric acid, acting as a complexing agent, can form stable complexes with the dissolved metal ions, preventing their redeposition on the liner surface and ensuring effective activation. Urotropine plays a stabilizing role during activation, regulating the rate and extent of the activation reaction, making the activation process more stable. These components work synergistically to bring the liner surface to a suitable activation state, creating conditions for a tight bond between the coating and the liner, thus improving coating durability and preventing peeling.

[0020] Optionally, in S1, the activation treatment method is as follows: the degreased perforated liner is immersed in the pore activation solution, and ultrasonic treatment is used to promote the penetration of the pore activation solution into the depth area of ​​the pore. The ultrasonic frequency is controlled at 15-20kHz, the activation temperature at 35-45℃, and the activation time at 18-25min. After activation, the pore is rinsed with deionized water for 1-3min and the surface of the perforated liner is dried with nitrogen.

[0021] By employing the above technical solution, the degreased perforated liner is immersed in an activation solution, and ultrasonic treatment is used simultaneously. The cavitation effect and stirring action generated by ultrasound promote the penetration of the activation solution into the depth of the pores, resulting in more uniform and thorough activation. Controlling the ultrasonic frequency at 15-20kHz effectively promotes penetration without damaging the liner. An activation temperature of 35-45℃ and an activation time of 18-25 minutes ensure a complete activation reaction. After activation, the pores are rinsed with deionized water for 1-3 minutes, and then the liner surface is dried with nitrogen gas to prevent residual moisture from causing re-oxidation of the liner or affecting subsequent plating processes. This improves the bonding quality between the plating layer and the liner, and enhances the durability of the plating layer.

[0022] Optionally, in S2, the composite complexing agent in the nickel-tungsten electroless plating solution includes citric acid and potassium sodium tartrate in a mass ratio of (1-2):1; the composite reducing agent includes sodium hypophosphite and hydrazine in a mass ratio of (4-5):1.

[0023] Optionally, in S2, the modified tungsten carbide nanoparticles are prepared using the following method:

[0024] Tungsten carbide nanoparticles were added to an ethanol solution and ultrasonically dispersed for 15-20 min. Then, γ-aminopropyltriethoxysilane was added, with the amount of γ-aminopropyltriethoxysilane being 3%-5% of the mass of the tungsten carbide nanoparticles. The mixture was stirred and reacted at 60-70℃ for 1-2 h. After centrifugation and drying, modified tungsten carbide nanoparticles were obtained.

[0025] By employing the above-mentioned technical solution, ultrasonic dispersion of nano-tungsten carbide particles in an ethanol solution ensures uniform dispersion of the particles, preventing agglomeration. The addition of γ-aminopropyltriethoxysilane, at 60-70℃, allows for a reaction with the nano-tungsten carbide particles. The amount of γ-aminopropyltriethoxysilane added is 3%-5% of the mass of the nano-tungsten carbide particles. This chemical reaction forms an organosilicon film on the particle surface, improving the interfacial bonding between the nano-tungsten carbide particles and the nickel-tungsten alloy matrix. The modified nano-tungsten carbide particles obtained after stirring, reaction, and centrifugal drying exhibit better dispersion in the plating solution and participate in coating formation, enhancing the hardness and wear resistance of the coating and improving its durability.

[0026] Optionally, in S3, the nanocomposite sealing liquid comprises the following components: 18-25 g / L silica sol, 7-12 g / L γ-glycidyl etheroxypropyltrimethoxysilane, 1.2-2.5 g / L nano alumina particles, and 35-45 g / L ethanol.

[0027] By employing the above technical solution, the silica sol forms a silicon-oxygen network structure during the sealing process, filling the pores of the coating and providing a physical sealing effect. γ-glycidyl etheroxypropyltrimethoxysilane reacts chemically with the silica sol and the coating surface, enhancing the adhesion between the sealing layer and the coating. Nano-alumina particles possess high hardness and good wear resistance; their addition to the sealing solution improves the hardness and wear resistance of the sealing layer. Ethanol, as a solvent, improves the dispersibility of the components, allowing the sealing solution to uniformly fill the pores. These components work together to form a dense sealing layer, effectively preventing corrosive media from penetrating the coating, thereby improving the coating's durability and resistance to peeling.

[0028] Optionally, the specific operation of chemical plating in step S2 may also include: every 15 minutes during the plating process, the plating solution in the channel is sampled through a sampling tube to detect the nickel ion concentration. When the nickel ion concentration is lower than 25 g / L, 100 g / L of nickel salt solution is added until the nickel ion concentration is restored to 28-35 g / L to ensure the stability of the plating solution composition in the channel.

[0029] Secondly, this application provides a nickel-tungsten alloy coating for perforated liner tubes, which is prepared using the above-described preparation process.

[0030] Thanks to the aforementioned preparation process, optimizations were achieved in all stages: pretreatment, plating, and post-treatment. Pretreatment ensures a clean and highly active liner surface, providing a solid foundation for a tight bond between the plating layer and the liner. Precise control of the chemical components and process parameters during plating results in a uniform, dense nickel-tungsten alloy plating layer with high hardness and wear resistance. Post-treatment further enhances the corrosion resistance and stability of the plating layer. Therefore, this plating layer exhibits excellent overall performance, enabling long-term use in complex environments without significant peeling, thus significantly improving the service life and reliability of perforated liners.

[0031] In summary, this application has the following beneficial effects:

[0032] 1. This application optimizes the substrate surface condition through a multi-step pretreatment process. During pretreatment, a degreasing solution effectively removes oil and impurities from the liner surface and pores. A peristaltic pump continuously pumps in the degreasing solution and performs backwashing to ensure no residue remains in the pores. A pore activation solution rapidly dissolves the oxide film, exposing a fresh metal surface. Ultrasonic treatment promotes the penetration of the activation solution into the depth of the pores, resulting in more uniform and thorough activation. These measures provide a clean and highly active substrate for coating adhesion, significantly enhancing the bonding strength between the coating and the substrate. This effectively solves the problem of easy coating detachment caused by poor adhesion, ensuring long-term stable service of the perforated liner under complex operating conditions.

[0033] 2. In the plating process, the components of the nickel-tungsten electroless plating solution provided in this application work synergistically. Nickel sulfate and sodium tungstate provide the source of metal ions, the composite complexing agent stabilizes the metal ion concentration, and the composite reducing agent promotes the reduction of metal ions to metal, forming a dense plating layer. In particular, modified nano-tungsten carbide particles prepared by a specific method are added to the plating solution. The organosilicon film formed on its surface improves the interfacial bonding performance with the nickel-tungsten alloy substrate, allowing it to be better dispersed in the plating solution and participate in the plating layer formation. This enhances the hardness and wear resistance of the plating layer, enabling it to better withstand media corrosion, particle erosion, and periodic pressure fluctuations, thus extending the service life of the perforated liner.

[0034] 3. The post-processing of this application comprehensively improves the durability of the coating. The perforated liner after coating is immersed in an acidic passivation solution to form a protective film, preventing oxidation and corrosion of the coating. A columnar ultrasonic probe is used to ultrasonically impact the coating in the channels and transition areas at the edges of the holes, eliminating internal stress and enhancing the adhesion between the coating and the substrate. A nano-composite sealing solution fills the pores of the coating, silica sol forms a silicon-oxygen network structure for physical sealing, γ-glycidyl etheroxypropyltrimethoxysilane enhances the adhesion between the sealing layer and the coating, and nano-alumina particles improve the hardness and wear resistance of the sealing layer, effectively preventing corrosive media from penetrating the interior of the coating, thereby improving the corrosion resistance and stability of the coating and preventing coating peeling. Detailed Implementation

[0035] The present application will be further described in detail below with reference to the embodiments.

[0036] Preparation example of modified tungsten carbide nanoparticles

[0037] Preparation Example 1

[0038] Modified tungsten carbide nanoparticles were prepared using the following method:

[0039] 100g of nano-tungsten carbide particles were added to 800g of 30% ethanol solution and ultrasonically dispersed at 600W for 20min. Then, 3g of γ-aminopropyltriethoxysilane was added and stirred at 60℃ for 2h. After centrifugation and drying, modified nano-tungsten carbide particles were obtained.

[0040] Preparation Example 2

[0041] Modified tungsten carbide nanoparticles were prepared using the following method:

[0042] 100g of nano-tungsten carbide particles were added to 800g of 30% ethanol solution and ultrasonically dispersed at 700W for 18min. Then, 4g of γ-aminopropyltriethoxysilane was added and the mixture was stirred at 65℃ for 1.5h. After centrifugation and drying, modified nano-tungsten carbide particles were obtained.

[0043] Preparation Example 3

[0044] Modified tungsten carbide nanoparticles were prepared using the following method:

[0045] 100g of nano-tungsten carbide particles were added to 800g of 30% ethanol solution and ultrasonically dispersed at 800W for 15min. Then, 5g of γ-aminopropyltriethoxysilane was added and the mixture was stirred at 70℃ for 1h. After centrifugation and drying, modified nano-tungsten carbide particles were obtained.

[0046] Example

[0047] Experimental substrate: Perforated liner (material: 20# carbon steel, outer diameter 50mm, inner diameter 30mm, hole specifications: hole diameter 8mm, hole depth 15mm, hole spacing 10mm, 6 holes in total).

[0048] Example 1

[0049] A process for preparing a nickel-tungsten alloy coating for a perforated liner includes the following steps:

[0050] S1. Pretreatment: The degreasing solution for the pores consists of: 20 g / L sodium hydroxide, 15 g / L sodium carbonate, 8 g / L sodium silicate, 3 g / L disodium EDTA, and 1 g / L fatty alcohol polyoxyethylene ether, with the remainder being deionized water. First, the perforated liner is completely immersed in the degreasing solution. Simultaneously, the degreasing solution is continuously pumped into the liner pores using a peristaltic pump at a flow rate of 1.5 mL / min, controlling the degreasing temperature at 60℃ and the degreasing time at 30 min. After degreasing, the residual degreasing solution in the pores is first purged with compressed air, and then the pores are backwashed with deionized water for 1.5 min.

[0051] The pore activation solution consisted of 25 mL / L hydrochloric acid, 8 mL / L hydrofluoric acid, 15 g / L citric acid, and 2 g / L hexamethylenetetramine, with the remainder being deionized water. The degreased perforated liner was immersed in the pore activation solution, and ultrasonic treatment was used to promote the penetration of the activation solution into the depth of the pores. The ultrasonic frequency was controlled at 18 kHz, the activation temperature at 40℃, and the activation time at 20 min. After activation, the pores were rinsed with deionized water for 2 min, and the surface of the perforated liner was dried with nitrogen gas.

[0052] S2. Plating: The nickel-tungsten electroless plating solution consists of: 30 g / L nickel sulfate, 12 g / L sodium tungstate, 45 g / L composite complexing agent (in which the mass ratio of citric acid to potassium sodium tartrate is 1.5:1), 25 g / L composite reducing agent (in which the mass ratio of sodium hypophosphite to hydrazine is 4.5:1), 1.5 g / L hexadecyltrimethylammonium bromide, and 1 g / L modified nano-tungsten carbide particles, with the balance being deionized water. The preparation method of the nickel-tungsten electroless plating solution is as follows: First, add nickel sulfate and sodium tungstate sequentially to deionized water and stir until completely dissolved; then add the composite complexing agent and continue stirring to make the solution homogeneous; then add the composite reducing agent and stir to mix; next, add hexadecyltrimethylammonium bromide and stir thoroughly; finally, add the modified nano-tungsten carbide particles and then ultrasonically disperse for 15 min to obtain the nickel-tungsten electroless plating solution.

[0053] The pretreated perforated liner was placed in a nickel-tungsten electroless plating solution and electroless plating was performed at 85°C. After 3 hours of plating, a nickel-tungsten alloy coating was formed. During the plating process, the plating solution inside the channel was sampled every 15 minutes through a sampling tube to detect the nickel ion concentration. When the nickel ion concentration was lower than 25 g / L, 100 g / L of nickel salt solution was added until the nickel ion concentration recovered to 30 g / L.

[0054] S3. Post-treatment: Immerse the plated perforated liner in an acidic passivation solution and maintain the temperature at 45℃ for 20 minutes. The acidic passivation solution is a mixed solution of nitric acid and chromic anhydride, with a nitric acid mass concentration of 10% and a chromic anhydride mass concentration of 8%. After passivation, use a columnar ultrasonic probe to ultrasonically impact the coating in the pores and the transition zone at the pore edges of the perforated liner. The impact frequency is 30kHz, the impact pressure is 0.3MPa, and each pore undergoes 5 intermittent impacts with a 30s interval between each impact. Then, immerse the perforated liner in a nanocomposite sealing solution for sealing and maintain the temperature at 70℃ for 30 minutes. The nanocomposite sealing solution consists of: 20g / L silica sol, 9g / L γ-glycidyl etheroxypropyltrimethoxysilane, 1.8g / L nano-alumina particles, and 40g / L ethanol, with the remainder being deionized water.

[0055] Example 2

[0056] A process for preparing a nickel-tungsten alloy coating for a perforated liner includes the following steps:

[0057] S1. Pretreatment: The degreasing solution for the pores consists of: sodium hydroxide 18g / L, sodium carbonate 12g / L, sodium silicate 6g / L, disodium EDTA 2g / L, and fatty alcohol polyoxyethylene ether 0.8g / L, with the remainder being deionized water. First, the perforated liner is completely immersed in the degreasing solution. Simultaneously, the degreasing solution is continuously pumped into the liner pores using a peristaltic pump at a flow rate of 1mL / min, controlling the degreasing temperature at 55℃ and the degreasing time at 25min. After degreasing, the remaining degreasing solution in the pores is first purged with compressed air, and then the pores are backwashed with deionized water for 1min.

[0058] The pore activation solution consisted of 22 mL / L hydrochloric acid, 6 mL / L hydrofluoric acid, 12 g / L citric acid, and 1.5 g / L hexamethylenetetramine, with the remainder being deionized water. The degreased perforated liner was immersed in the pore activation solution, and ultrasonic treatment was used to promote the penetration of the activation solution into the depth of the pores. The ultrasonic frequency was controlled at 15 kHz, the activation temperature at 35℃, and the activation time at 18 min. After activation, the pores were rinsed with deionized water for 1 min, and the surface of the perforated liner was dried with nitrogen gas.

[0059] S2. Plating: The nickel-tungsten electroless plating solution consists of: 28 g / L nickel sulfate, 10 g / L sodium tungstate, 38 g / L composite complexing agent (in which the mass ratio of citric acid to potassium sodium tartrate is 1:1), 20 g / L composite reducing agent (in which the mass ratio of sodium hypophosphite to hydrazine is 4:1), 1.2 g / L hexadecyltrimethylammonium bromide, and 0.8 g / L modified nano-tungsten carbide particles, with the balance being deionized water. The preparation method of the nickel-tungsten electroless plating solution is as follows: First, add nickel sulfate and sodium tungstate sequentially to deionized water and stir until completely dissolved; then add the composite complexing agent and continue stirring to make the solution homogeneous; then add the composite reducing agent and stir to mix; next, add hexadecyltrimethylammonium bromide and stir thoroughly; finally, add the modified nano-tungsten carbide particles and then ultrasonically disperse for 15 min to obtain the nickel-tungsten electroless plating solution.

[0060] The pretreated perforated liner was placed in a nickel-tungsten electroless plating solution and electroless plating was performed at 80°C. After 3 hours of plating, a nickel-tungsten alloy coating was formed. During the plating process, the plating solution inside the pores was sampled every 15 minutes through a sampling tube to detect the nickel ion concentration. When the nickel ion concentration was lower than 25 g / L, 100 g / L of nickel salt solution was added until the nickel ion concentration recovered to 30 g / L.

[0061] S3. Post-treatment: Immerse the plated perforated liner in an acidic passivation solution and maintain the temperature at 40℃ for 15 minutes. The acidic passivation solution is a mixed solution of nitric acid and chromic anhydride, with a nitric acid mass concentration of 10% and a chromic anhydride mass concentration of 7%. After passivation, use a columnar ultrasonic probe to ultrasonically impact the coating in the pores and the transition zone at the pore edges. The impact frequency is 30kHz, the impact pressure is 0.3MPa, and each pore undergoes 5 intermittent impacts with a 30s interval between each impact. Then, immerse the perforated liner in a nanocomposite sealing solution for sealing and maintain the temperature at 70℃ for 30 minutes. The nanocomposite sealing solution consists of: 18g / L silica sol, 7g / L γ-glycidyl etheroxypropyltrimethoxysilane, 1.2g / L nano-alumina particles, and 35g / L ethanol, with the balance being deionized water.

[0062] Example 3

[0063] A process for preparing a nickel-tungsten alloy coating for a perforated liner includes the following steps:

[0064] S1. Pretreatment: The degreasing solution for the pores consists of: sodium hydroxide 25g / L, sodium carbonate 18g / L, sodium silicate 12g / L, disodium EDTA 4g / L, and fatty alcohol polyoxyethylene ether 1.5g / L, with the remainder being deionized water. First, the perforated liner is completely immersed in the degreasing solution. Simultaneously, the degreasing solution is continuously pumped into the liner pores using a peristaltic pump at a flow rate of 2mL / min, controlling the degreasing temperature at 65℃ and the degreasing time at 35min. After degreasing, the remaining degreasing solution in the pores is first purged with compressed air, and then the pores are backwashed with deionized water for 2min.

[0065] The pore activation solution consisted of 30 mL / L hydrochloric acid, 10 mL / L hydrofluoric acid, 18 g / L citric acid, and 3 g / L hexamethylenetetramine, with the remainder being deionized water. The degreased perforated liner was immersed in the pore activation solution, and ultrasonic treatment was used to promote the penetration of the activation solution into the depth of the pores. The ultrasonic frequency was controlled at 20 kHz, the activation temperature at 45℃, and the activation time at 25 min. After activation, the pores were rinsed with deionized water for 3 min, and the surface of the perforated liner was dried with nitrogen.

[0066] S2. Plating: The nickel-tungsten electroless plating solution consists of: 35 g / L nickel sulfate, 15 g / L sodium tungstate, 55 g / L composite complexing agent (in which the mass ratio of citric acid to potassium sodium tartrate is 2:1), 32 g / L composite reducing agent (in which the mass ratio of sodium hypophosphite to hydrazine is 5:1), 2 g / L hexadecyltrimethylammonium bromide, and 1.5 g / L modified nano-tungsten carbide particles, with the balance being deionized water. The preparation method of the nickel-tungsten electroless plating solution is as follows: First, add nickel sulfate and sodium tungstate sequentially to deionized water and stir until completely dissolved; then add the composite complexing agent and continue stirring to make the solution homogeneous; then add the composite reducing agent and stir to mix; next, add hexadecyltrimethylammonium bromide and stir thoroughly; finally, add the modified nano-tungsten carbide particles and then ultrasonically disperse for 20 min to obtain the nickel-tungsten electroless plating solution.

[0067] The pretreated perforated liner was placed in a nickel-tungsten electroless plating solution and electroless plating was performed at 90°C. After 3 hours of plating, a nickel-tungsten alloy coating was formed. During the plating process, the plating solution inside the pores was sampled every 15 minutes through a sampling tube to detect the nickel ion concentration. When the nickel ion concentration was lower than 25 g / L, 100 g / L of nickel salt solution was added until the nickel ion concentration recovered to 30 g / L.

[0068] S3. Post-treatment: Immerse the plated perforated liner in an acidic passivation solution and maintain the temperature at 50℃ for 25 minutes. The acidic passivation solution is a mixed solution of nitric acid and chromic anhydride, with a nitric acid mass concentration of 10% and a chromic anhydride mass concentration of 6.5%. After passivation, use a columnar ultrasonic probe to ultrasonically impact the coating in the pores and the transition zone at the pore edges. The impact frequency is 30kHz, and the impact pressure is 0.3MPa. Each pore undergoes 5 intermittent impacts with a 30s interval between each impact. Then, immerse the perforated liner in a nanocomposite sealing solution for sealing and maintain the temperature at 80℃ for 25 minutes. The nanocomposite sealing solution consists of: 25g / L silica sol, 12g / L γ-glycidyl etheroxypropyltrimethoxysilane, 2.5g / L nano-alumina particles, and 45g / L ethanol, with the remainder being deionized water.

[0069] Example 4

[0070] A process for preparing a nickel-tungsten alloy coating for a perforated liner differs from Example 1 in that the composition of the degreasing solution for the pores is different; in this example, fatty alcohol polyoxyethylene ether is not added to the degreasing solution. Specifically, the composition of the degreasing solution for the pores in this example is as follows:

[0071] Sodium hydroxide 22 g / L, sodium carbonate 16 g / L, sodium silicate 10 g / L, disodium EDTA 3.5 g / L, with the remainder being deionized water.

[0072] Example 5

[0073] A process for preparing a nickel-tungsten alloy coating for a perforated liner differs from Example 1 in that the composition of the pore activation solution is different; citric acid and hexamethylenetetramine are not added to the pore activation solution in this example. Specifically, the composition of the pore activation solution in this example is as follows:

[0074] Hydrochloric acid 28 mL / L, hydrofluoric acid 9 mL / L, with the remainder being deionized water.

[0075] Example 6

[0076] A process for preparing a nickel-tungsten alloy coating for perforated liners differs from Example 1 in that the composition of the nanocomposite sealing solution is different. In this example, the nanocomposite sealing solution does not contain γ-glycidyl etheroxypropyltrimethoxysilane or nano-alumina particles. Specifically, the composition of the nanocomposite sealing solution in this example is as follows:

[0077] The silica sol was 22 g / L, the ethanol was 42 g / L, and the remainder was deionized water.

[0078] Comparative Example

[0079] Comparative Example 1

[0080] A process for preparing a nickel-tungsten alloy coating for a perforated liner differs from Example 1 in that: in this comparative example, no modified nano-tungsten carbide particles are added to the nickel-tungsten electroless plating solution in S2, while other parameters are the same as in Example 1.

[0081] Comparative Example 2

[0082] A process for preparing a nickel-tungsten alloy coating for a perforated liner differs from Example 1 in that: in this comparative example, a columnar ultrasonic probe was not used in S3 to ultrasonically impact the coating in the channel and the transition zone at the edge of the hole; other parameters are the same as in Example 1.

[0083] Comparative Example 3

[0084] A process for preparing a nickel-tungsten alloy coating for a perforated liner differs from Example 1 in that: in this comparative example, the perforated liner was not degreased in S1 using a pore degreasing solution, while other parameters are the same as in Example 1.

[0085] Comparative Example 4

[0086] A process for preparing a nickel-tungsten alloy coating for a perforated liner differs from Example 1 in that: in this comparative example, the perforated liner was not activated in S1 using a pore activation solution, while other parameters are the same as in Example 1.

[0087] Performance testing

[0088] Test items:

[0089] 1. Adhesion: The adhesion of the coating in the depth area of ​​the channel (8mm from the orifice) was tested according to the pull-out method in GB / T5270-2005.

[0090] 2. Erosion resistance: Simulating petrochemical working conditions (5% NaCl solution containing 3% SiO2 particles, flow rate 3m / s, 40℃, rinsing for 240h), the percentage of coating peeling area was tested;

[0091] 3. Corrosion resistance: Neutral salt spray test (GB / T10125-2021), testing the corrosion rate of the coating after 500 hours.

[0092] The experimental results are shown in Table 1.

[0093] Table 1 Performance test results

[0094]

[0095] The coating adhesion in Examples 1-3 all reached a high level, at 47.5 MPa, 45.9 MPa, and 47.2 MPa, respectively. This indicates that the preparation process described in this application, including the synergistic effect of pretreatment, plating, and post-treatment, enables the coating to form a tight bond with the perforated liner substrate. Under complex operating conditions such as petrochemical fluid transportation and precision hydraulic systems, this high adhesion effectively prevents the coating from detaching due to media erosion and pressure fluctuations, ensuring the long-term stable service of the perforated liner. In the erosion resistance test simulating petrochemical operating conditions, the coating detachment area in Examples 1-3 was low, at 0.35%, 0.38%, and 0.36%, respectively. This demonstrates that the coating has good wear resistance and erosion resistance, maintaining its integrity under long-term erosion by media containing particles, reducing the risk of liner body wear and pore blockage caused by coating detachment. Neutral salt spray test results showed that the corrosion rates of the coatings in Examples 1-3 were all very low, at 0.0012 mm / a, 0.0015 mm / a, and 0.0013 mm / a, respectively. This demonstrates the excellent corrosion resistance of the coating, effectively preventing the intrusion of corrosive media, protecting the inner wall of the perforated liner from corrosion, and extending the service life of the liner. Overall, Examples 1-3 prove that the preparation process of this application, under different parameter combinations, can effectively improve the durability, anti-stripping performance, and corrosion resistance of the nickel-tungsten alloy coating of the perforated liner, meeting the stringent requirements for surface coatings of perforated liners in fields such as petrochemicals and precision hydraulic systems.

[0096] The difference between Example 4 and Example 1 is that fatty alcohol polyoxyethylene ether was not added to the degreasing solution for the pores. Performance testing results show that all performance indicators of Example 4 decreased. The coating adhesion of Example 4 decreased to 39.6 MPa, significantly lower than that of Example 1. This is because fatty alcohol polyoxyethylene ether, as a nonionic surfactant, can reduce the surface tension of the degreasing solution, allowing it to better penetrate into the depth of the pores and remove oil and impurities. Without this component, oil residue may remain in the pores, affecting the adhesion between the coating and the substrate, leading to a decrease in adhesion. In the erosion resistance test, the coating peeling area of ​​Example 4 increased to 1.28%. The reduced adhesion makes the coating more prone to peeling under the influence of the medium, indicating that fatty alcohol polyoxyethylene ether plays an important role in ensuring a tight bond between the coating and the substrate, thereby improving the coating's erosion resistance.

[0097] Compared to Example 1, Example 5 did not include citric acid and hexamethylenetetramine in the pore activation solution. Performance testing results showed that the performance of Example 5 was also deteriorated. The coating adhesion of Example 5 was 41.3 MPa, lower than that of Example 1. Citric acid, as a complexing agent, can form stable complexes with dissolved metal ions, preventing metal ions from redepositing on the liner surface and ensuring the activation effect; hexamethylenetetramine plays a stabilizing role in the activation process, regulating the rate and extent of the activation reaction. Without these two components, the activation process may not be uniform or thorough enough, leading to a decrease in the adhesion between the coating and the substrate. Erosion resistance testing showed that the coating peeling area in Example 5 accounted for 1.25%. The reduced adhesion made the coating easier to peel off during erosion, indicating that citric acid and hexamethylenetetramine are important for improving the adhesion between the coating and the substrate, thereby enhancing the coating's erosion resistance.

[0098] The coating adhesion in Example 6 was 42.7 MPa, lower than that in Example 1. Although the sealing solution mainly fills the pores of the coating, γ-glycidoxypropyltrimethoxysilane can chemically react with the silica sol and the coating surface, enhancing the adhesion between the sealing layer and the coating, indirectly affecting the overall adhesion performance between the coating and the substrate. In the erosion resistance test, the coating peeling area in Example 6 accounted for 1.23%. Nano-alumina particles have high hardness and good wear resistance; adding them to the sealing solution can improve the hardness and wear resistance of the sealing layer. Without this component, the performance of the sealing layer deteriorates, making the coating more susceptible to damage and peeling during erosion.

[0099] Compared to Example 1, Comparative Example 1 did not include modified nano-tungsten carbide particles in its nickel-tungsten electroless plating solution. Performance testing results showed a significant decrease in the performance of Comparative Example 1. The coating adhesion of Comparative Example 1 was only 28.5 MPa, far lower than that of Example 1. The organosilicon film formed on the surface of the modified nano-tungsten carbide particles improved the interfacial bonding performance with the nickel-tungsten alloy substrate, allowing for better dispersion in the plating solution and participation in coating formation, thus enhancing the hardness and adhesion of the coating. The absence of this component severely affected the structure and performance of the coating, leading to a significant reduction in adhesion. In the erosion resistance test, the coating peeling area of ​​Comparative Example 1 reached as high as 7.68%. The reduced adhesion made the coating extremely prone to peeling under the erosion of the medium, indicating that the modified nano-tungsten carbide particles play a crucial role in improving the erosion resistance of the coating. The corrosion rate of Comparative Example 1 was 0.0038 mm / a, significantly higher than that of Example 1. The decrease in coating adhesion and erosion resistance makes the inner wall of the liner more exposed to corrosive media, accelerating the corrosion process and reducing the corrosion resistance of the coating.

[0100] Compared to Example 1, Comparative Example 2 did not use a cylindrical ultrasonic probe to ultrasonically impact the coating in the transition zone of the pores and pore edges. The coating adhesion in Comparative Example 2 was 30.2 MPa, lower than that in Example 1. Ultrasonic impact can eliminate internal stress in the coating and enhance the adhesion between the coating and the substrate. Without this step, the internal stress in the coating may not be effectively eliminated, leading to a decrease in adhesion. In the erosion resistance test, the coating detachment area in Comparative Example 2 was 6.32%. The reduced adhesion makes the coating more prone to detachment during erosion, indicating that ultrasonic impact plays an important role in improving the erosion resistance of the coating. The corrosion rate in Comparative Example 2 was 0.0032 mm / a, higher than that in Example 1. The decrease in coating adhesion and erosion resistance affects the overall corrosion resistance of the coating, as coating detachment accelerates the corrosion of the inner wall of the liner.

[0101] Comparative Example 3 did not use a pore degreasing solution to degrease the perforated liner, and Comparative Example 4 did not use a pore activation solution to activate the perforated liner. The performance test results of both comparative examples were poor. The coating adhesion of Comparative Example 3 was 25.9 MPa, and that of Comparative Example 4 was 22.8 MPa, both significantly lower than that of Example 1. The degreasing and activation steps in the pretreatment are crucial for removing oil and impurities from the liner surface and pores, and for enhancing the surface activity of the substrate. Without these steps, it is difficult for the coating to form a tight bond with the substrate, resulting in a significant decrease in adhesion. In the erosion resistance test, the coating peeling area of ​​Comparative Example 3 was 8.17%, and that of Comparative Example 4 was 8.85%. The severe reduction in adhesion makes the coating extremely prone to large-area peeling under the scouring of the medium, indicating that the pretreatment steps play a fundamental role in ensuring the erosion resistance of the coating. The corrosion rate of Comparative Example 3 was 0.0045 mm / a, and that of Comparative Example 4 was 0.0052 mm / a, both significantly higher than that of Example 1. The decrease in coating adhesion and erosion resistance leads to an increase in the area of ​​the inner wall of the liner directly exposed to the corrosive medium, which accelerates the corrosion process and severely reduces the corrosion resistance of the coating.

[0102] In summary, the performance test data analysis of the embodiments and comparative examples shows that each step and component in the preparation process of this application plays a crucial role in improving the durability, anti-peeling performance, and corrosion resistance of the nickel-tungsten alloy coating on the perforated liner. The optimization of each stage of pretreatment, plating, and post-treatment, as well as the rational combination of each chemical solution component, can effectively solve the problems of insufficient durability and easy peeling of the nickel-tungsten coating in the application of perforated liners, significantly improving the service life and reliability of the perforated liner.

[0103] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A process for the production of a nickel tungsten alloy plating for a cased pipe, characterized in that, The method comprises the following steps: S1, pretreatment: firstly, a hole degreasing solution is used to perform degreasing treatment on the hole lining pipe, and then a hole activation solution is used to perform activation treatment on the hole lining pipe; The hole degreasing solution comprises the following components: sodium hydroxide 18-25 g / L, sodium carbonate 12-18 g / L, sodium silicate 6-12 g / L, disodium EDTA 2-4 g / L and fatty alcohol polyoxyethylene ether 0.8-1.5 g / L; The hole activation solution comprises the following components: hydrochloric acid 22-30 mL / L, hydrofluoric acid 6-10 mL / L, citric acid 12-18 g / L and urotropine 1.5-3 g / L; S2, plating: the hole lining pipe after the pretreatment is placed in a nickel-tungsten chemical plating solution to perform chemical plating at 80-90 ℃ to form a nickel-tungsten alloy plating layer; the nickel-tungsten chemical plating solution comprises the following components: nickel sulfate 28-35 g / L, sodium tungstate 10-15 g / L, a composite complexing agent 38-55 g / L, a composite reducing agent 20-32 g / L, cetyltrimethylammonium bromide 1.2-2 g / L and modified nano tungsten carbide particles 0.8-1.5 g / L; The composite complexing agent in the nickel-tungsten chemical plating solution comprises citric acid and potassium sodium tartrate in a mass ratio of (1-2):1; the composite reducing agent comprises sodium hypophosphite and hydrazine in a mass ratio of (4-5):1; The preparation method of the modified nano tungsten carbide particles is as follows: the nano tungsten carbide particles are added into an ethanol solution, ultrasonic dispersion is performed for 15-20 min, then γ-aminopropyl triethoxysilane is added, the amount of the γ-aminopropyl triethoxysilane added is 3%-5% of the mass of the nano tungsten carbide particles, stirring reaction is performed at 60-70 ℃ for 1-2 h, and the modified nano tungsten carbide particles are obtained after centrifugal drying; S3, post-treatment: the hole lining pipe after the plating is immersed in an acidic passivation solution, and is kept at 40-50 ℃ for 15-25 min; then the plating layer of the hole and the hole edge transition zone is subjected to ultrasonic impact by using a columnar ultrasonic probe; then the hole lining pipe is placed in a nano composite hole sealing solution for sealing treatment; The nano composite hole sealing solution comprises the following components: silica sol 18-25 g / L, γ-glycidyl ether oxypropyl trimethoxysilane 7-12 g / L, nano alumina particles 1.2-2.5 g / L and ethanol 35-45 g / L.

2. A process for the preparation of a nickel tungsten alloy coating for a cuffed liner according to claim 1, characterized in that: In S1, the method for the degreasing treatment is as follows: the hole lining pipe is completely immersed in the hole degreasing solution, and the hole degreasing solution is continuously pumped into the hole of the lining pipe at a flow rate of 1-2 mL / min by using a peristaltic pump, the degreasing temperature is controlled to be 55-65 ℃, and the degreasing time is 25-35 min; after the degreasing is completed, the residual degreasing solution in the hole is first blown off by using compressed air, and then the hole is backwashed by using deionized water for 1-2 min.

3. The process for preparing a nickel tungsten alloy coating for a cuffed liner as claimed in claim 1, wherein: In S1, the method for the activation treatment is as follows: the hole lining pipe after the degreasing is immersed in the hole activation solution, and ultrasonic treatment is used to promote the penetration of the hole activation solution to the deep area of the hole, the ultrasonic frequency is controlled to be 15-20 kHz, the activation temperature is controlled to be 35-45 ℃, and the activation time is 18-25 min; after the activation is completed, the hole is washed by using deionized water for 1-3 min, and the hole lining pipe is dried by using nitrogen.

4. The process for preparing a nickel tungsten alloy coating for a cuffed liner as claimed in claim 1, wherein: The specific operation of electroless plating in step S2 further comprises: during the plating process, the plating solution in the hole is extracted through a sampling pipe every 15 min, the nickel ion concentration is detected, when the nickel ion concentration is lower than 25 g / L, 100 g / L of nickel salt solution is supplemented, until the nickel ion concentration is restored to 28-35 g / L, to ensure that the composition of the plating solution in the hole is stable.

5. A nickel tungsten alloy plating for a cased tubing characterized by: The preparation process of any one of claims 1-4 is used to prepare.

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