Corrosion-resistant ball valve and machining method thereof

Abstract

The invention relates to a corrosion-resistant ball valve which comprises a ball valve body, a corrosion-resistant coating is arranged on the ball valve body, and the corrosion-resistant coating comprises the following components: methyl phenyl silicone resin, bisphenol A epoxy resin, 3-aminopropyltriethoxysilane, nano sol, a dispersing agent and absolute ethyl alcohol. The invention further relates to a machining method of the corrosion-resistant ball valve. The machining method comprises the steps of degreasing and oil removal, sand blasting treatment, corrosion-resistant coating preparation and corrosion-resistant coating spraying. The corrosion-resistant coating has the following advantages and effects that the methyl phenyl silicone resin and the bisphenol A epoxy resin are cooperated, so that the corrosion-resistant coating has high adhesive force, mechanical strength, heat resistance, weather resistance and flexibility; 3-aminopropyltriethoxysilane introduces amino groups to bisphenol A epoxy resin for functional modification, so that the compatibility and the interface bonding force are improved; and the further addition of the nano sol is beneficial to prolonging the permeation path of a corrosive medium, and the micropores are subjected to hole sealing treatment, so that the compactness is further improved, and the corrosion resistance is improved.

Description

Technical Field

[0001] This application relates to the technical field of ball valves, and in particular to a corrosion-resistant ball valve and its processing method. Background Technology

[0002] In industrial fluid control systems, ball valves are widely used in various fields such as petroleum, chemical, natural gas, power, pharmaceutical and water treatment due to their advantages such as simple structure, rapid opening and closing and excellent sealing performance.

[0003] However, when conveying highly corrosive media (such as acids, alkalis, salt solutions, chlorine, wet chlorine, sulfur-containing oil and gas, etc.), ball valves made of traditional metal materials (such as carbon steel and ordinary stainless steel) are prone to electrochemical corrosion, pitting corrosion, stress corrosion cracking, etc., which can lead to shortened valve life, sealing failure, and even leakage, safety accidents and environmental pollution.

[0004] Regarding the aforementioned technologies, the current method of spraying anti-corrosion coatings onto the valve body surface still suffers from poor stability at high temperatures and requires further improvement. Summary of the Invention

[0005] To improve the stability of the anti-corrosion coating at high temperatures, this application provides a corrosion-resistant ball valve and its processing method.

[0006] Firstly, the corrosion-resistant ball valve provided in this application adopts the following technical solution: A corrosion-resistant ball valve includes a ball valve body, wherein the ball valve body is provided with a corrosion-resistant coating, the corrosion-resistant coating comprising the following components in parts by weight: 20-30 parts methylphenyl silicone resin; 12-15 parts bisphenol A type epoxy resin; 1-2 parts of 3-aminopropyltriethoxysilane; 10-12 parts nano-sol; 0.8-1.2 parts dispersant; 5-6 parts anhydrous ethanol.

[0007] By adopting the above technical solution, organosilicon methylphenyl silicone resin can form a SiO2 skeleton after decomposition at 300–600℃. Bisphenol A type epoxy resin has excellent mechanical properties, adhesion and chemical resistance. The two work together to make the corrosion-resistant coating combine the high adhesion and mechanical strength of epoxy resin with the heat resistance, weather resistance and flexibility of silicone resin. 3-aminopropyltriethoxysilane introduces amino groups into the bisphenol A type epoxy resin for functional modification, improving compatibility and interfacial bonding. The further addition of nano-sol helps to extend the penetration path of corrosive media and seal micropores, further improving density and corrosion resistance.

[0008] Preferably, the processing method of the nano sol is as follows, based on parts by weight: 10-12 parts of Zn(NO3)2·6H2O and 5-6 parts of AlCl3 are mixed with deionized water in a weight ratio of 3:1 to prepare Zn(NO3)2 solution and AlCl3 solution. Under nitrogen protection and at 60-70℃, add Zn(NO3)2 solution and AlCl3 solution dropwise while stirring, adjust the pH value to 8-9, and after the addition is complete, add 3-4 parts of sodium benzotriazole, continue stirring at 60-80℃ for 8-10 hours, cool to room temperature, centrifuge, and wash the precipitate with deionized water until the conductivity is <50μS / cm; Then add 10-12 parts of deionized water and sonicate at 200-240W for 5-7 minutes. After standing, sonicate again and repeat 3 times. The colloidal particle size is 30-80nm and the solid content is 1-5wt.

[0009] By employing the above technical solution and introducing corrosion-inhibiting anions by adding sodium benzotriazole, a modified layered bimetallic hydroxide nanosol was prepared. - Penetrating the coating, it can adsorb Cl - This achieves active protection, while the layered structure provides a "maze effect" to block the diffusion of corrosive media and effectively improve corrosion resistance. In addition, bisphenol A type epoxy resin has high cross-linking ability and can synergistically form an organic-inorganic hybrid network structure with nanosol.

[0010] Preferably, the corrosion-resistant coating further comprises 3-5 parts by weight of diethylenetriaminepentamethylenephosphonic acid.

[0011] By adopting the above technical solution, the phosphonic acid groups contained in diethylenetriamine pentamethylphosphonic acid have strong coordination, high water solubility, and excellent metal chelating ability. They can form stable covalent coordination bonds with metal cations, that is, diethylenetriamine pentamethylphosphonic acid can be firmly adsorbed on the surface of layered bimetallic hydroxide nanosol to form a dense chelate film, thereby giving it higher corrosion resistance. The organic framework of diethylenetriamine pentamethylphosphonic acid can also improve the dispersibility of layered bimetallic hydroxide nanosol in bisphenol A type epoxy resin.

[0012] Preferably, the corrosion-resistant coating further includes 1-2 parts of curing agent by weight.

[0013] By adopting the above technical solution, a curing agent is added, and the main organic network is formed by cross-linking with bisphenol A type epoxy resin through a curing machine. The amino groups introduced by 3-aminopropyltriethoxysilane can also participate in epoxy curing, increasing the cross-linking point density. The modified layered bimetallic hydroxide nanosol is embedded in the network to become inorganic cross-linking nodes, thereby forming an interpenetrating hybrid network structure and improving corrosion resistance.

[0014] Preferably, the curing agent is a ketimine curing agent.

[0015] Preferably, the dispersant is BYK-P 104.

[0016] Secondly, this application provides a method for processing a corrosion-resistant ball valve, employing the following technical solution: A method for processing a corrosion-resistant ball valve includes the following steps: S1. Degreasing and oil removal; removing grease and dirt from the surface of the ball valve body; S2. Sandblasting treatment; control the surface roughness to Ra 4.0-6.3μm; S3. Preparation of corrosion-resistant coating: Bisphenol A type epoxy resin is heated in a water bath at 50-60℃ and stirred at 200-400rpm. A mixture of 3-aminopropyltriethoxysilane and anhydrous ethanol is slowly added dropwise. The temperature is raised to 70-80℃ and the reaction is stirred for 2-4h to obtain mixture A. At pH 6, the nano-sol was slowly added to mixture A and stirred at 55-60℃ for 1-1.5 h; the curing agent was added and stirred rapidly for 10 min; finally, methylphenyl silicone resin and dispersant were added. S4. Spray corrosion-resistant coating; spray the corrosion-resistant coating onto the ball valve body, and spray again after it is surface dry, for a total of 3 times, with a single layer dry film thickness of 100-150μm.

[0017] Preferably, step S3 further includes the following steps: at 40-50°C, diethylenetriamine pentamethylphosphonic acid is slowly added dropwise to the nanosol while stirring. After the addition is complete, stirring is continued for 2-4 hours to obtain mixture B. At pH 6, slowly add mixture B to mixture A and stir at 55-60℃ for 1-1.5 hours; add curing agent and stir rapidly for 10 minutes; finally add methylphenyl silicone resin and dispersant and stir for 30-50 minutes.

[0018] In summary, this application includes the following beneficial technical effects: 1. Organosilicon methylphenyl silicone resin can form a SiO2 skeleton after decomposition at 300–600℃. Bisphenol A type epoxy resin has excellent mechanical properties, adhesion and chemical resistance. The synergy between the two makes the corrosion-resistant coating combine the high adhesion and mechanical strength of epoxy resin with the heat resistance, weather resistance and flexibility of silicone resin. 3-Aminopropyltriethoxysilane introduces amino groups into the bisphenol A type epoxy resin for functional modification, improving compatibility and interfacial bonding. The further addition of nano-sol helps to extend the penetration path of corrosive media and seal micropores, further improving density and corrosion resistance. 2. By adding sodium benzotriazole to introduce corrosion-inhibiting anions, a modified layered bimetallic hydroxide nanosol was prepared. - Penetrating the coating, it can adsorb Cl - This achieves active protection, while the layered structure provides a "maze effect" to block the diffusion of corrosive media and effectively improve corrosion resistance. In addition, bisphenol A epoxy resin has high cross-linking ability and can synergistically form an organic-inorganic hybrid network structure with nanosol. 3. The phosphonic acid group contained in diethylenetriamine pentamethylphosphonic acid has strong coordination, high water solubility, and excellent metal chelating ability. It can form stable covalent coordination bonds with metal cations. That is, diethylenetriamine pentamethylphosphonic acid can be firmly adsorbed on the surface of layered bimetallic hydroxide nanosol to form a dense chelate film, thereby giving it higher corrosion resistance. The organic framework of diethylenetriamine pentamethylphosphonic acid can also improve the dispersibility of layered bimetallic hydroxide nanosol in bisphenol A type epoxy resin. 4. Add a curing agent and crosslink it with bisphenol A type epoxy resin through a curing machine to form a main organic network. The amino groups introduced by 3-aminopropyltriethoxysilane can also participate in epoxy curing, increasing the crosslinking point density. The modified layered bimetallic hydroxide nanosol is embedded in the network to become inorganic crosslinking nodes, thereby forming an interpenetrating hybrid network structure and improving corrosion resistance. Detailed Implementation

[0019] The following provides a further detailed description of this application.

[0020] In this application, the methylphenyl silicone resin was provided by Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.; the bisphenol A type epoxy resin was provided by Jiangyin Wanqian Chemical Co., Ltd., grade 901, with an epoxy equivalent of 450-500 g / eq; 3-aminopropyltriethoxysilane, CAS: 919-30-2; sodium benzotriazole was provided by Klein (Shandong) Biotechnology Co., Ltd., CAS: 15217-42-2; diethylenetriamine pentamethylphosphonic acid was a 50% aqueous solution, CAS: 15827-60-8; the ketimine curing agent was HS-865 ketimine curing agent provided by Jiangsu Jufeng Chemical Technology Co., Ltd.; and BYK-P 104 was provided by Guangzhou Siteyuan Chemical Co., Ltd.

[0021] Unless otherwise specified, all raw materials used in the following embodiments are commercially available.

[0022] Example Example 1: This example discloses a corrosion-resistant ball valve and its processing method; a corrosion-resistant ball valve includes a ball valve body, on which a corrosion-resistant coating is provided. The corrosion-resistant coating includes the following components: methylphenyl silicone resin, bisphenol A type epoxy resin, 3-aminopropyltriethoxysilane, nano sol, dispersant and anhydrous ethanol, wherein the dispersant is BYK-P 104, and the content of each component is shown in Table 1 below.

[0023] A method for processing a corrosion-resistant ball valve includes the following steps: S1. Degreasing and oil removal; removing grease and dirt from the surface of the ball valve body; S2. Sandblasting treatment; surface roughness controlled to Ra 4.0μm; S3. Preparation of corrosion-resistant coating: Bisphenol A type epoxy resin was heated in a 50°C water bath and stirred at 200 rpm. A mixture of 3-aminopropyltriethoxysilane and anhydrous ethanol was slowly added dropwise. The temperature was raised to 70°C and the reaction was continued for 2 hours to obtain mixture A. At pH 6, the nano-sol was slowly added to mixture A and stirred at 55°C for 1 hour; the curing agent was added and stirred rapidly for 10 minutes; finally, methylphenyl silicone resin and dispersant were added. S4. Spray corrosion-resistant coating; spray the corrosion-resistant coating onto the ball valve body, and spray again after it is surface dry, for a total of 3 times, with a single layer dry film thickness of 100μm.

[0024] X-ray diffraction of the nanosol revealed strong and sharp diffraction peaks characteristic of layered bimetallic hydroxide structures, such as (003), (006), and (012), at a low angle of 2θ = 10-30°. Infrared spectroscopy characterization showed that at 1600 cm⁻¹... -1 1450cm -1 750cm -1 The presence of C=C, C=N, and N–N vibrational peaks of the aromatic ring of benzotriazole confirms successful loading of benzotriazole.

[0025] Example 2: The difference from Example 1 is that this example discloses a corrosion-resistant ball valve and its processing method; a corrosion-resistant ball valve includes a ball valve body, on which a corrosion-resistant coating is provided. The corrosion-resistant coating includes the following components: methylphenyl silicone resin, bisphenol A type epoxy resin, 3-aminopropyltriethoxysilane, nano sol, dispersant and anhydrous ethanol, wherein the dispersant is BYK-P 104, and the content of each component is shown in Table 1 below.

[0026] A method for processing a corrosion-resistant ball valve includes the following steps: S1. Degreasing and oil removal; removing grease and dirt from the surface of the ball valve body; S2. Sandblasting treatment; control the surface roughness to Ra 5.0μm; S3. Preparation of corrosion-resistant coating: Bisphenol A type epoxy resin was heated in a 55°C water bath and stirred at 300 rpm. A mixture of 3-aminopropyltriethoxysilane and anhydrous ethanol was slowly added dropwise. The temperature was raised to 75°C and the reaction was stirred for 3 hours to obtain mixture A. At pH 6, the nano-sol was slowly added to mixture A and stirred at 58°C for 1.2 h; the curing agent was added and stirred rapidly for 10 min; finally, methylphenyl silicone resin and dispersant were added. S4. Spray corrosion-resistant coating; spray the corrosion-resistant coating onto the ball valve body, and spray again after it is surface dry, for a total of 3 times, with a single layer dry film thickness of 100μm.

[0027] Example 3: The difference from Example 1 is that this example discloses a corrosion-resistant ball valve and its processing method; a corrosion-resistant ball valve includes a ball valve body, on which a corrosion-resistant coating is provided. The corrosion-resistant coating includes the following components: methylphenyl silicone resin, bisphenol A type epoxy resin, 3-aminopropyltriethoxysilane, nano sol, dispersant and anhydrous ethanol, wherein the dispersant is BYK-P 104, and the content of each component is shown in Table 1 below.

[0028] A method for processing a corrosion-resistant ball valve includes the following steps: S1. Degreasing and oil removal; removing grease and dirt from the surface of the ball valve body; S2. Sandblasting treatment; surface roughness controlled to Ra 6.3μm; S3. Preparation of corrosion-resistant coating: Bisphenol A type epoxy resin was heated in a 60℃ water bath and stirred at 400rpm. A mixture of 3-aminopropyltriethoxysilane and anhydrous ethanol was slowly added dropwise. The temperature was raised to 80℃ and the reaction was stirred for 4h to obtain mixture A. At pH 6, the nano-sol was slowly added to mixture A and stirred at 60°C for 1.5 h; the curing agent was added and stirred rapidly for 10 min; finally, methylphenyl silicone resin and dispersant were added. S4. Spray corrosion-resistant coating; spray the corrosion-resistant coating onto the ball valve body, and spray again after it is surface dry, for a total of 3 times, with a single layer dry film thickness of 150μm.

[0029] Example 4: The difference from Example 1 is that this example discloses a corrosion-resistant ball valve and its processing method; a corrosion-resistant ball valve includes a ball valve body, on which a corrosion-resistant coating is provided. The corrosion-resistant coating includes the following components: methylphenyl silicone resin, bisphenol A type epoxy resin, 3-aminopropyltriethoxysilane, nano sol, dispersant, anhydrous ethanol, a 50% aqueous solution of diethylenetriaminepentamethylenephosphonic acid, and a curing agent. The dispersant is BYK-P 104, and the curing agent is a ketimine curing agent. The content of each component is shown in Table 1 below.

[0030] A method for manufacturing a corrosion-resistant ball valve, S3 further includes the following steps: At 40°C, diethylenetriaminepentamethylphosphonic acid was slowly added dropwise to the nanosol while stirring. After the addition was complete, stirring was continued for 2 hours to obtain mixture B. At pH 6, mixture B was slowly added to mixture A and stirred at 55°C for 1 hour; then the curing agent was added and stirred rapidly for 10 minutes; finally, methylphenyl silicone resin and dispersant were added and stirred for 30 minutes.

[0031] S4. Spray corrosion-resistant coating; spray the corrosion-resistant coating onto the ball valve body, and spray again after it is surface dry, for a total of 3 times, with a single layer dry film thickness of 100μm.

[0032] Product B was characterized by infrared spectroscopy at 1000-1200 cm⁻¹. -1 There are strong stretching vibration peaks at 1640 cm⁻¹ for phosphonic acid groups P=O and POC. -1 and 1550cm -1 The presence of NH bending vibrations confirms that diethylenetriaminepentimidephosphonic acid was successfully adsorbed or bonded to the surface of nanoparticles.

[0033] Example 5: The difference from Example 2 is that this example discloses a corrosion-resistant ball valve and its processing method; a corrosion-resistant ball valve includes a ball valve body, on which a corrosion-resistant coating is provided. The corrosion-resistant coating includes the following components: methylphenyl silicone resin, bisphenol A type epoxy resin, 3-aminopropyltriethoxysilane, nano sol, dispersant, anhydrous ethanol, a 50% aqueous solution of diethylenetriaminepentamethylenephosphonic acid, and a curing agent. The dispersant is BYK-P 104, and the curing agent is a ketimine curing agent. The content of each component is shown in Table 1 below.

[0034] A method for manufacturing a corrosion-resistant ball valve, S3 further includes the following steps: At 45°C, diethylenetriaminepentamethylphosphonic acid was slowly added dropwise to the nanosol while stirring. After the addition was complete, stirring was continued for 3 hours to obtain mixture B. At pH 6, mixture B was slowly added to mixture A and stirred at 58°C for 1.2 h; then the curing agent was added and stirred rapidly for 10 min; finally, methylphenyl silicone resin and dispersant were added and stirred for 40 min.

[0035] Example 6: The difference from Example 3 is that this example discloses a corrosion-resistant ball valve and its processing method; a corrosion-resistant ball valve includes a ball valve body, on which a corrosion-resistant coating is provided. The corrosion-resistant coating includes the following components: methylphenyl silicone resin, bisphenol A type epoxy resin, 3-aminopropyltriethoxysilane, nano sol, dispersant, anhydrous ethanol, a 50% aqueous solution of diethylenetriaminepentamethylenephosphonic acid, and a curing agent. The dispersant is BYK-P 104, and the curing agent is a ketimine curing agent. The content of each component is shown in Table 1 below.

[0036] A method for manufacturing a corrosion-resistant ball valve, S3 further includes the following steps: At 50°C, diethylenetriaminepentamethylphosphonic acid was slowly added dropwise to the nanosol while stirring. After the addition was complete, stirring was continued for 4 hours to obtain mixture B. At pH 6, mixture B was slowly added to mixture A and stirred at 60°C for 1.5 h; then the curing agent was added and stirred rapidly for 10 min; finally, methylphenyl silicone resin and dispersant were added and stirred for 50 min.

[0037] Example 7: The difference from Example 1 is that the corrosion-resistant coating also includes a 50% aqueous solution of diethylenetriamine pentamethylphosphonic acid.

[0038] Example 8: The difference from Example 7 is that the 50% aqueous solution of diethylenetriaminepentamethylphosphonic acid is replaced with the 50% aqueous solution of hydroxyethylidene diphosphonic acid.

[0039] Example 9: The difference from Example 4 is that the curing agent is replaced with polyamide.

[0040] Comparative Example Comparative Example 1: The difference from Example 1 is that the corrosion-resistant coating component consists of only 20 parts by weight of methylphenyl silicone resin and 12 parts by weight of bisphenol A type epoxy resin.

[0041] Comparative Example 2: The difference from Example 1 is that the bisphenol A type epoxy resin was replaced with hydrogenated bisphenol A type epoxy resin.

[0042] Comparative Example 3: The difference from Example 1 is that 3-aminopropyltriethoxysilane was replaced with 3-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0043] Comparative Example 4: The difference from Example 1 is that the nanosol was replaced with a mixture of 7 parts by weight of montmorillonite and 3 parts by weight of sodium benzotriazole.

[0044] Table 1. Component content of Examples 1-6 Performance testing Test method: Salt spray resistance test was conducted according to ASTM B117 / GB / T 10125. A 5% NaCl solution was sprayed continuously at 35°C to test the corrosion spread width at the scratch. The results are shown in Table 2 below.

[0045] Table 2 Performance test results of each embodiment and comparative example This specific embodiment is merely an explanation of this application and is not intended to limit the scope of protection of this application. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of this application, they are protected by patent law.

Claims

1. A corrosion-resistant ball valve, comprising a ball valve body, characterized in that: The ball valve body is provided with a corrosion-resistant coating, which comprises the following components in parts by weight: 20-30 parts methylphenyl silicone resin; 12-15 parts bisphenol A type epoxy resin; 1-2 parts of 3-aminopropyltriethoxysilane; 10-12 parts nano-sol; 0.8-1.2 parts dispersant; 5-6 parts anhydrous ethanol.

2. The corrosion-resistant ball valve according to claim 1, characterized in that: The processing method of the nano sol is as follows, based on parts by weight: 10-12 parts of Zn(NO3)2·6H2O and 5-6 parts of AlCl3 are mixed with deionized water in a weight ratio of 3:1 to prepare Zn(NO3)2 solution and AlCl3 solution. Under nitrogen protection and at 60-70℃, add Zn(NO3)2 solution and AlCl3 solution dropwise while stirring, adjust the pH value to 8-9, and after the addition is complete, add 3-4 parts of sodium benzotriazole, continue stirring at 60-80℃ for 8-10 hours, cool to room temperature, centrifuge, and wash the precipitate with deionized water until the conductivity is <50μS / cm; Then add 10-12 parts of deionized water and sonicate at 200-240W for 5-7 minutes. After standing, sonicate again and repeat 3 times. The colloidal particle size is 30-80nm and the solid content is 1-5wt%.

3. The corrosion-resistant ball valve according to claim 2, characterized in that: The corrosion-resistant coating also includes 3-5 parts by weight of diethylenetriaminepentamethylphosphonic acid.

4. A corrosion-resistant ball valve according to claim 3, characterized in that: The corrosion-resistant coating also includes 1-2 parts of curing agent by weight.

5. A corrosion-resistant ball valve according to claim 4, characterized in that: The curing agent is a ketimine curing agent.

6. A corrosion-resistant ball valve according to claim 1, characterized in that: The dispersant is BYK-P 104.

7. The processing method of the corrosion-resistant ball valve according to claim 1, characterized in that, Includes the following steps: S1. Degreasing and oil removal; removing grease and dirt from the surface of the ball valve body; S2. Sandblasting treatment; control the surface roughness to Ra 4.0-6.3μm; S3. Preparation of corrosion-resistant coating: Bisphenol A type epoxy resin is heated in a water bath at 50-60℃ and stirred at 200-400rpm. A mixture of 3-aminopropyltriethoxysilane and anhydrous ethanol is slowly added dropwise. The temperature is raised to 70-80℃ and the reaction is stirred for 2-4h to obtain mixture A. At pH 6, the nano-sol was slowly added to mixture A and stirred at 55-60℃ for 1-1.5 h; the curing agent was added and stirred rapidly for 10 min; finally, methylphenyl silicone resin and dispersant were added. S4. Spray corrosion-resistant coating; spray the corrosion-resistant coating onto the ball valve body, and spray again after it is surface dry, for a total of 3 times, with a single layer dry film thickness of 100-150μm.

8. A method for processing a corrosion-resistant ball valve according to claim 7, characterized in that: The S3 further includes the following steps: at 40-50℃, 3-5 parts of diethylenetriamine pentamethylphosphonic acid are slowly added dropwise to the nano sol while stirring. After the addition is complete, stirring is continued for 2-4 hours to obtain mixture B. At pH 6, slowly add mixture B to mixture A and stir at 55-60℃ for 1-1.5 hours; add 1-2 parts of curing agent and stir rapidly for 10 minutes; finally, add 20-30 parts of methylphenyl silicone resin and 0.8-1.2 parts of dispersant and stir for 30-50 minutes.

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