Novel surface strengthening treatment method for special valve

Abstract

The invention relates to the technical field of special valve surface treatment, and discloses a novel special valve surface strengthening treatment method which comprises the following steps: S1, surface pretreatment: cleaning the surface of a special valve and removing an oxide layer to remove surface impurities and the oxide layer; s2, laser surface micro-texture treatment is conducted, specifically, a micron-sized texture pattern is prepared on the surface of the valve through the laser technology; s3, physical vapor deposition, wherein a titanium nitride hard coating and a tungsten carbide hard coating are sequentially deposited on the surface of the pretreated valve; s4, chemical composite plating: adding a nano-particle reinforced phase to the surface of the hard coating through a chemical composite plating process; s5, ion implantation reinforcement; and S6, carrying out post-treatment. The titanium nitride hard coating and the tungsten carbide hard coating are sequentially deposited on the surface of the valve subjected to laser surface micro-texture treatment, so that the hardness and wear resistance of the surface of the valve are improved, the surface is endowed with good corrosion resistance and oxidation resistance, the service life of the valve under severe working conditions is prolonged, and the applicability of the valve under different environments is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of surface treatment of special valves, and specifically to a new method for surface strengthening treatment of special valves. Background Art

[0002] In many fields such as industrial production, energy development, and transportation, special valves, as key components for controlling fluid flow, pressure, and direction, directly affect the operating efficiency and safety of the entire system. With the development of technology and the continuous expansion of application scenarios, valves need to cope with more complex and harsh working conditions, such as high temperature, high pressure, strong corrosion, high wear, etc. Therefore, it is necessary to strengthen the surface of special valves to adapt to use in different environments. Traditional surface treatment of special valves mostly uses a single coating for treatment.

[0003] However, in the current technology, single coating treatment has problems such as difficulty in coping with complex working conditions, insufficient bonding strength with the substrate, poor durability, easy aging, and difficult repair. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a new method for surface strengthening treatment of special valves, which solves the problems that single coating treatment makes it difficult for special valves to cope with complex working conditions and reduces the service life and applicability of the valves.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A new method for surface strengthening treatment of special valves, including the following steps:

[0006] S1. Surface pretreatment: Clean and remove the oxide layer on the surface of the special valve to remove surface impurities and the oxide layer;

[0007] S2. Laser surface micro-texturing treatment: Use laser technology to prepare micron-scale texture patterns on the valve surface;

[0008] S3. Physical vapor deposition: Sequentially deposit titanium nitride and tungsten carbide hard coatings on the surface of the pretreated valve;

[0009] S4. Chemical composite plating: Add nano-particle reinforcement phases on the surface of the hard coating through chemical composite plating process to form a strengthened layer with a gradient structure;

[0010] S5. Ion implantation strengthening: Use ion implantation technology to implant nitrogen ions, carbon ions, or metal ions into the coating surface;

[0011] S6. Post-treatment: Anneal and polish the coating surface, and then cover the surface of the special valve with rust preventive oil through soaking.

[0012] Preferably, the S1 specifically includes the following steps:

[0013] S101. Remove the oxide layer on the surface of the special valve by mechanical grinding or sandblasting;

[0014] S102. Then use pickling or alkali washing to remove the surface oil and impurities of the special valve;

[0015] S103. Finally, further clean the special surface by ultrasonic cleaning.

[0016] Preferably, the laser texture pattern in S2 includes pits, grooves or grids, the texture depth is 1 - 50 microns, and the width is 10 - 100 microns.

[0017] Preferably, S3 specifically includes the following steps:

[0018] S301. Place the pretreated special valve into the vacuum chamber of the deposition equipment, evacuate the air to form a vacuum environment;

[0019] S302. Then introduce nitrogen and the gaseous source of titanium, and deposit on the surface of the special valve by arc ion plating to form a titanium nitride hard coating;

[0020] S303. After the deposition of the titanium nitride coating is completed, introduce hydrocarbon gas and the gaseous source of tungsten, and continue to deposit a tungsten carbide coating on the titanium nitride coating by arc ion plating again.

[0021] Preferably, the thickness of the hard coating is 1 - 10 microns.

[0022] Preferably, S4 specifically includes the following steps:

[0023] S401. Form a transition layer on the surface of the hard coating by electroless nickel plating process;

[0024] S402. Add nano - particle reinforcing phases into the transition layer, and the nano - particles are also embedded into the coating along with the deposition of the metal. The nano - particles include silicon carbide, aluminum nitride and aluminum oxide;

[0025] S403. As the deposition time increases, the thickness of the coating gradually increases, and the content and distribution of its nano - particles also change, forming a strengthening layer with a gradient structure.

[0026] Preferably, the ions injected in S5 include nitrogen ions, carbon ions, titanium ions or tungsten ions, the injection energy is 10 - 200 keV, and the injection dose is 1×10 16 -1×10 18 ions / cm 2 .

[0027] Preferably, the strengthening layer with a gradient structure from the surface to the inside is in turn:

[0028] Outer layer: Titanium nitride and tungsten carbide hard coatings;

[0029] Intermediate layer: Chemical composite coating containing nano-particle reinforcement phase;

[0030] Inner layer: Transition layer bonded to the outer surface of the special valve.

[0031] The present invention provides a new method for surface strengthening treatment of special valves. It has the following beneficial effects:

[0032] 1. By successively depositing titanium nitride and tungsten carbide hard coatings on the surface of the valve after laser surface micro-texturing treatment, the present invention improves the hardness and wear resistance of the valve surface, endows the surface with good corrosion resistance and oxidation resistance, extends the service life of the valve under harsh working conditions, and its applicability in different environments.

[0033] 2. By adding nano-particle reinforcement phase on the surface of the hard coating through chemical composite plating process to form a strengthening layer with gradient structure, the present invention further optimizes the mechanical properties and functionality of the coating. The nano-particle reinforcement phase can improve the hardness, toughness and corrosion resistance of the coating, thus alleviating the stress concentration between the coating and the substrate through the gradient structure and preventing the coating from failing.

[0034] 3. The present invention adopts ion implantation technology to inject nitrogen, carbon or metal ions into the coating surface with high energy. The ions collide and embed with the coating atoms, changing their composition and structure. Thus, without changing the macroscopic size and shape of the coating, the surface hardness, wear resistance and corrosion resistance of the coating are significantly improved, a surface compressive stress layer is formed to enhance the fatigue resistance, and the service life of the valve under extreme working conditions is effectively extended. Description of the Drawings

[0035] Figure 1 It is a flow chart of the new method for surface strengthening treatment of the special valve of the present invention;

[0036] Figure 2 It is a schematic diagram of the titanium nitride coating of the new method for surface strengthening treatment of the special valve of the present invention;

[0037] Figure 3 It is a schematic diagram of the tungsten carbide coating of the new method for surface strengthening treatment of the special valve of the present invention. Detailed Embodiments

[0038] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] Please refer to the attachedFigure 1 - Attachment Figure 3 , The embodiment of the present invention provides a new method for surface strengthening treatment of special valves, including the following steps:

[0040] S1. Surface pretreatment: Clean and remove the oxide layer on the surface of the special valve to remove surface impurities and oxide layer;

[0041] S2. Laser surface micro-texture treatment: Use laser technology to prepare micron-scale texture patterns on the valve surface;

[0042] S3. Physical vapor deposition: Sequentially deposit titanium nitride and tungsten carbide hard coatings on the surface of the pretreated valve;

[0043] S4. Chemical composite plating: Add nano-particle reinforcement phases on the surface of the hard coating through chemical composite plating process to form a strengthening layer with a gradient structure;

[0044] S5. Ion implantation strengthening: Use ion implantation technology to implant nitrogen ions, carbon ions or metal ions into the coating surface;

[0045] S6. Post-treatment: Anneal and polish the coating surface, and then cover the surface of the special valve with rust-proof oil by soaking.

[0046] Specifically, through S1 for cleaning and removing the oxide layer, impurities, oil stains and oxide layer on the surface of the special valve are removed, providing a clean and activated surface for subsequent coating deposition, thereby improving the bonding strength between the subsequent coating and the substrate material, avoiding coating peeling or defects caused by surface contamination, and ensuring the uniformity and stability of the subsequent process;

[0047] Through S2, micron-scale texture patterns are prepared on the valve surface by using laser technology to increase the surface roughness and specific surface area, which can improve the mechanical biting effect between the coating and the substrate, enhance the mechanical interlocking effect on the surface, improve the lubricity and wear resistance of the surface, improve the stress distribution of the coating, and prevent coating peeling;

[0048] Through S3, titanium nitride and tungsten carbide hard coatings are sequentially deposited on the surface of the pretreated valve. The titanium nitride coating has good hardness, wear resistance and corrosion resistance, and the tungsten carbide coating further improves the hardness and anti-wear ability of the coating, thereby improving the hardness and wear resistance of the valve surface and endowing the surface with good corrosion resistance and oxidation resistance, extending the service life of the valve under harsh working conditions and its applicability in different environments;

[0049] By S4, nano-particle reinforced phases are added to the surface of the hard coating through a chemical composite plating process to form a strengthening layer with a gradient structure, further optimizing the mechanical properties and functionality of the coating. The nano-particle reinforced phases can improve the hardness, toughness, and corrosion resistance of the coating, while the gradient structure alleviates the stress concentration between the coating and the substrate, preventing coating failure.

[0050] By S5, nitrogen ions, carbon ions, or metal ions are implanted into the coating surface using ion implantation technology. The ion beam impacts the coating surface with high energy, causing the ions to collide with and embed into the atoms in the coating, changing the composition and structure of the coating surface. Thus, without changing the macroscopic size and shape of the coating, the hardness, wear resistance, and corrosion resistance of the coating surface are significantly improved. At the same time, a surface compressive stress layer is formed, enhancing the fatigue resistance and extending the service life of the valve under extreme working conditions.

[0051] By S6, annealing treatment can eliminate the internal stress in the coating, improve the bonding strength and stability of the coating. Polishing treatment improves the surface finish and reduces the frictional resistance. Then, covering with rust preventive oil further enhances the corrosion resistance of the valve, thereby improving the stability and reliability of the coating, further enhancing the corrosion resistance of the valve surface, extending the service life of the valve, and improving the appearance quality of the valve.

[0052] S1 specifically includes the following steps:

[0053] S101: Remove the oxide layer on the surface of the special valve by mechanical grinding or sandblasting.

[0054] S102: Then, use pickling or alkali washing to remove the surface oil and impurities of the special valve.

[0055] S103: Finally, further clean the special surface by ultrasonic cleaning.

[0056] Specifically, in S101, tools such as sandpaper and grinding wheels are used to rub the valve surface to directly remove the oxide layer physically. And in sandblasting, high-speed ejected sand grains impact the valve surface, and the oxide layer is peeled off by the impact force and frictional force of the sand grains. Also, the valve surface becomes rougher, increasing the contact area between the subsequent treatment process and the valve substrate, improving the mechanical bonding force between the coating bodies, and creating good surface conditions for the subsequent treatment steps. At the same time, removing the oxide layer also helps to more accurately detect whether there are defects such as cracks and sand holes on the valve surface.

[0057] Through pickling or alkali washing in S102, chemical reactions occur with the oil stains and impurities on the metal surface to clean the valve surface. After removing the oil stains and impurities, the chemical properties of the valve surface become more uniform, which is conducive to subsequent chemical reactions and coating deposition, improving the bonding strength and uniformity between the coating and the substrate. At the same time, the clean surface also helps to improve the corrosion resistance of the valve and reduce local corrosion caused by oil stains and impurities.

[0058] Through ultrasonic cleaning in S103, a powerful impact force is generated, which can shake off the tiny dirt remaining on the valve surface and disperse it into the cleaning liquid, thus achieving all-round cleaning deep into the fine structure of the valve surface without damaging the valve surface, maintaining the flatness and smoothness of the valve surface, and facilitating the smooth progress of subsequent processing techniques, further improving the bonding quality between the coating and the substrate.

[0059] The laser texture pattern in S2 includes pits, grooves or grids, with a texture depth of 1 - 50 microns and a width of 10 - 100 microns.

[0060] Specifically, the pits can serve as tiny oil storage pools to store lubricating oil during the operation of the valve, continuously provide lubrication for the friction surface, and reduce the friction coefficient. The grooves can guide the fluid flow, optimize the internal fluid dynamics performance of the valve, reduce fluid resistance and energy loss, and enhance the sealing effect at the sealing part. The grid-like texture effectively improves the tribological performance and fluid control performance of the valve by increasing the surface area and enhancing the mechanical interlocking ability of the surface, improving the wear resistance and sealing performance of the valve, and significantly extending the service life of the valve under complex working conditions.

[0061] S3 specifically includes the following steps:

[0062] S301: Place the pretreated special valve into the vacuum chamber of the deposition equipment, evacuate the air to form a vacuum environment.

[0063] S302: Then introduce nitrogen and the gaseous source of titanium, and deposit on the surface of the special valve through arc ion plating to form a titanium nitride hard coating.

[0064] S303: After the deposition of the titanium nitride coating is completed, introduce hydrocarbon gas and the gaseous source of tungsten, and continue to deposit a tungsten carbide coating on the titanium nitride coating through arc ion plating again.

[0065] Specifically, through S301, the vacuum environment can ensure that the gaseous source particles reach the valve surface with high energy and speed without being overly interfered, laying a foundation for the preparation of subsequent high-quality coatings. It ensures that the titanium nitride and tungsten carbide coatings can adhere tightly and evenly to the valve surface, achieving efficient and uniform deposition.

[0066] Under high vacuum conditions in S302, arc discharge causes the titanium target to evaporate and ionize, which chemically reacts with the introduced nitrogen gas to form titanium nitride particles. These particles fly towards the valve surface at high speed under the action of an electric field and deposit, forming a hard titanium nitride coating, thus significantly enhancing the hardness of the valve surface and greatly reducing the wear degree when facing working conditions such as friction and erosion.

[0067] In S303, hydrocarbon gas and a gaseous source of tungsten are introduced, and arc ion plating is used again to deposit a tungsten carbide coating on the titanium nitride coating. Tungsten carbide also has extremely high hardness and excellent wear resistance. Depositing a tungsten carbide coating on the basis of the titanium nitride coating can further enhance the hardness and wear resistance of the coating system, and the composite structure of the two coatings can exert a synergistic effect to improve the comprehensive performance of the coating.

[0068] The thickness of the hard coating is 1 - 10 microns.

[0069] The hard coating greatly enhances the wear resistance of the valve with its high hardness and strength, effectively resisting the frictional losses generated during frequent use to extend the service life.

[0070] S4 specifically includes the following steps:

[0071] S401: A transition layer is formed on the surface of the hard coating through electroless nickel plating.

[0072] S402: Nanoparticle reinforcing phases are added to the transition layer, and the nanoparticles are also embedded in the coating as the metal deposits. The nanoparticles include silicon carbide, aluminum nitride, and aluminum oxide.

[0073] S403: As the deposition time increases, the thickness of the coating gradually increases, and the content and distribution of its nanoparticles also change, forming a strengthened layer with a gradient structure.

[0074] Specifically, through S401, a transition layer is formed on the surface of the hard coating through electroless nickel plating, improving the bonding condition between the hard coating and the subsequently added nanoparticle reinforcing phases, constructing a transition region connecting the hard coating and the nanoparticle reinforcing phases, enabling the subsequent nanoparticles to be more stably embedded in the coating, improving the structural stability and integrity of the entire coating system, and laying a foundation for forming a gradient structure strengthened layer with excellent performance.

[0075] Through S402, nanoparticle reinforcing phases are added to the transition layer and evenly dispersed within the transition layer, which can hinder dislocation movement, improve the strength and hardness of the coating, and at the same time improve the wear resistance and corrosion resistance of the coating, enabling it to better resist external friction, wear, and corrosion, effectively extending the service life of the special valve, and improving its reliability under complex working conditions.

[0076] The S403 gradient structure enables the coating to have different performance characteristics at different depths. From the surface to the interior, the content of nanoparticles gradually changes, which can better adapt to the changes in surface stress and wear during the operation of the valve. That is, the relatively high content of nanoparticles on the surface provides high hardness and wear resistance, while the relatively low content of nanoparticles inside ensures good bonding strength and toughness between the coating and the substrate.

[0077] The ions implanted in S5 include nitrogen ions, carbon ions, titanium ions or tungsten ions, with an implantation energy of 10 - 200 keV and an implantation dose of 1×10 16 -1×10 18 ions / cm 2 。

[0078] Specifically, the high-energy ion beam bombards the surface of the coating, enabling the ions to be successfully embedded inside the coating, changing the crystal structure and atomic arrangement of the coating, thereby significantly increasing the surface hardness of the coating, enhancing its wear resistance, and effectively resisting various friction losses.

[0079] The strengthening layer with a gradient structure from the surface to the interior is in turn:

[0080] Outer layer: Titanium nitride and tungsten carbide hard coatings;

[0081] Intermediate layer: Chemical composite coating containing nanoparticle reinforcement phases;

[0082] Inner layer: Transition layer bonded to the outer surface of the special valve.

[0083] Specifically, as the part directly in contact with the external environment, the titanium nitride and tungsten carbide hard coatings can effectively resist the friction, wear and chemical erosion faced by the valve during operation. Tungsten carbide further enhances the hardness and wear resistance of the coating, enabling it to adapt to a more severe friction environment, thereby protecting the internal coating and the valve substrate from external physical and chemical damage;

[0084] The chemical composite coating in the intermediate layer is embedded with nanoparticle reinforcement phases, which can play a role in dispersion strengthening in the coating. They are evenly dispersed inside the coating, hindering dislocation movement, thereby increasing the overall strength and hardness of the coating. In addition, the chemical composite coating can further improve the wear resistance and corrosion resistance of the coating, and due to its good bonding properties with both the outer hard coating and the inner transition layer, it can play a good connecting role, making the entire coating system more stable;

[0085] The transition layer of the inner layer mainly serves as a bridge connecting the valve matrix and the outer layer coating. Since there are differences in the material properties of the valve matrix and the outer layer coating, direct bonding may lead to insufficient bonding strength. The transition layer is formed through processes such as electroless nickel plating, and its composition and structure have certain compatibility with both the valve matrix and the intermediate layer. It can relieve the internal stress generated by factors such as different thermal expansion coefficients between the matrix and the coating, enhance the adhesion between the coating and the matrix, and enable the entire coating system to firmly adhere to the valve surface.

[0086] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A new method for surface strengthening treatment of special valves, characterized in that, It includes the following steps: S1. Surface pretreatment: Clean the surface of the special valve and remove the oxide layer to remove surface impurities and the oxide layer; S2. Laser surface micro-texturing treatment: Use laser technology to prepare micron-scale texture patterns on the valve surface; S3. Physical vapor deposition: Sequentially deposit titanium nitride and tungsten carbide hard coatings on the pretreated valve surface; S4. Chemical composite plating: Add nano-particle reinforcement phases on the surface of the hard coating through chemical composite plating process to form a reinforced layer with a gradient structure; S5. Ion implantation strengthening: Use ion implantation technology to implant nitrogen ions, carbon ions or metal ions into the coating surface; S6. Post-treatment: Anneal and polish the coating surface, and then cover the surface of the special valve with antirust oil by soaking.

2. The new method for surface strengthening treatment of special valves according to claim 1, characterized in that, The specific steps of S1 include the following: S101. Remove the oxide layer on the surface of the special valve by mechanical grinding or sandblasting; S102. Then use pickling or alkali washing to remove surface oil stains and impurities from the special valve; S103. Finally, further clean the special surface by ultrasonic cleaning.

3. The new method for surface strengthening treatment of special valves according to claim 1 is characterized in that, The laser texture patterns in S2 include pits, grooves or grids, and the texture depth is 1 - 50 microns and the width is 10 - 100 microns.

4. The new method for surface strengthening treatment of special valves according to claim 1 is characterized in that, The specific steps of S3 include the following: S301. Put the pretreated special valve into the vacuum chamber of the deposition equipment, evacuate the air to form a vacuum environment; S302. Then introduce nitrogen and gaseous sources of titanium, and deposit on the surface of the special valve through arc ion plating to form a titanium nitride hard coating; S303. After the deposition of the titanium nitride coating is completed, introduce hydrocarbon gas and gaseous sources of tungsten, and continue to deposit tungsten carbide coating on the titanium nitride coating through arc ion plating again.

5. The new method for surface strengthening treatment of special valves according to claim 1 is characterized in that, The thickness of the hard coating is 1 - 10 microns.

6. The new method for surface strengthening treatment of special valves according to claim 1, characterized in that, The specific steps of S4 include the following: S401. Form a transition layer on the surface of the hard coating through electroless nickel plating process; S402. Add nano-particle reinforcement phases in the transition layer, and the nano-particles are also embedded in the coating as the metal is deposited. The nano-particles include silicon carbide, aluminum nitride and alumina; S403. As the deposition time increases, the coating thickness gradually increases, and the content and distribution of its nano-particles also change, forming a reinforced layer with a gradient structure.

7. The new method for surface strengthening treatment of special valves according to claim 1, characterized in that, The ions implanted in S5 include nitrogen ions, carbon ions, titanium ions or tungsten ions, with an implantation energy of 10 - 200 keV and an implantation dose of 1×10 16 -1×10 18 ions / cm 2 .

8. The new method for surface strengthening treatment of special valves according to claim 1, characterized in that, The reinforced layer with a gradient structure from the surface to the inside is in turn: Outer layer: Titanium nitride and tungsten carbide hard coatings; Middle layer: Chemical composite plating layer containing nano-particle reinforcement phases; Inner layer: Transition layer combined with the outer surface of the special valve.

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