Manufacturing method of anti-corrosion fastener

Abstract

The invention provides an anti-corrosion fastener manufacturing method which comprises the steps that a cylindrical cavity is formed in a fastener, and an anode column made of an anode material is arranged in the cylindrical cavity; the couple sequence of the anode material is lower than that of the fastener manufacturing material; determining the maximum sectional area of the cylindrical cavity according to the diameter of the fastener; and determining the minimum sectional area of the cylindrical cavity according to the target service life and the fastener length. The method has the beneficial effects that the cylindrical cavity is formed in the fastener, the cylindrical cavity is filled with the anode column made of the anode material, when the fastener is in a corrosion environment, the anode column is corroded firstly, the fastener is protected against corrosion by sacrifice of the anode material, the anode column is installed in the cylindrical cavity, and the sectional area of the cylindrical cavity is calculated, so that the corrosion resistance of the fastener is improved. The structural strength of the fastener is guaranteed, and the size of the fastener is not increased.

Description

Technical Field

[0001] The invention belongs to the technical field of fastener manufacturing, and in particular relates to a method for manufacturing an anti-corrosion fastener. Background Art

[0002] Fasteners are basic components, numbering in the tens of thousands and classified into groups. They play an important role in "connecting structures and systems". Their quality directly affects the life and reliability of equipment. In the fields of marine engineering, petrochemicals, offshore wind power, etc., fastening connection systems are often in a strongly corrosive environment during service. Fasteners, as key supporting connectors, fail in corrosive environments, resulting in equipment failures that are common and can easily lead to major accidents.

[0003] At present, the anti-corrosion methods of bolts in corrosive environments mainly include surface coating and plating technology. Among them, coating technology: Common anti-corrosion coatings include epoxy resin, polyurethane and fluorocarbon coatings, which prevent corrosion by forming a physical barrier on the surface of the bolt. Plating technology: The plating materials mainly include zinc plating, chrome plating, nickel plating, etc. For example, the common anti-corrosion plating method forms a zinc layer on the surface of the bolt by electroplating or hot-dip galvanizing to play an anti-corrosion role.

[0004] Current problems with anti-corrosion bolts: First, the coating is easily damaged: the anti-corrosion coating is easily damaged by mechanical means during installation and use, which greatly reduces the anti-corrosion effect. Once the coating is damaged, corrosion will quickly spread from the damaged area. Second, the durability of the coating is insufficient: although the coating material can provide good anti-corrosion performance, its durability is still limited when exposed to highly corrosive environments such as seawater for a long time, especially when the surface coating is impacted or worn, the protective effect is greatly reduced. Unable to provide long-term protection: existing technologies cannot effectively solve the anti-corrosion problem of bolts throughout their entire service life, especially in highly corrosive environments, which often require frequent maintenance and replacement, increasing maintenance costs and downtime. Summary of the invention

[0005] In view of this, the present invention aims to provide a method for manufacturing an anti-corrosion fastener, in order to solve at least one of the above-mentioned technical problems.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A first aspect of the present invention provides a method for manufacturing an anti-corrosion fastener.

[0008] A cylindrical cavity is provided in the fastener, and an anode column made of an anode material is arranged in the cylindrical cavity;

[0009] The galvanic sequence of the anode material is lower than the galvanic sequence of the material of which the fastener is made;

[0010] Determine the maximum cross-sectional area of ​​the cylindrical cavity according to the diameter of the fastener;

[0011] Determine the minimum cross-sectional area of ​​the cylindrical cavity based on the target service life and fastener length.

[0012] Furthermore, the fastener is a bolt, the cylindrical cavity is a cylindrical cavity, and the maximum diameter calculation formula of the cylindrical cavity is:

[0013]

[0014] Among them, d fil is the maximum diameter of the cylindrical cavity, d is the nominal diameter of the bolt, and P is the pitch of the bolt.

[0015] Furthermore, the fastener is a bolt, the cylindrical cavity is a cylindrical cavity, the cylindrical cavity is coaxially arranged with the bolt, the cylindrical cavity is provided with openings at both ends of the bolt, and the minimum diameter calculation formula of the cylindrical cavity is:

[0016]

[0017] d fil,min is the minimum diameter of the cylindrical cavity, m total is the corrosion quality of the designed service life, ρ is the density of the anode material, h head is the length of the bolt, h bolt is the bolt head length of the bolt.

[0018] Further, when the maximum cross-sectional area of ​​the cylindrical cavity is greater than the minimum cross-sectional area of ​​the cylindrical cavity, the area between the maximum cross-sectional area of ​​the cylindrical cavity and the minimum cross-sectional area of ​​the cylindrical cavity is selected as the cross-sectional area of ​​the cylindrical cavity;

[0019] When the maximum cross-sectional area of ​​the cylindrical cavity is smaller than the minimum cross-sectional area of ​​the cylindrical cavity, the maximum cross-sectional area of ​​the cylindrical cavity is used as the cross-sectional area of ​​the cylindrical cavity, and anode plates made of anode materials are arranged at both ends of the anode column;

[0020] The sum of the mass of the anode plate and the mass of the anode column is greater than the corrosion mass of the designed service life.

[0021] Further, the anode plate is a circular plate;

[0022] When the anode plate is located at the bolt head end of the bolt, the diameter of the anode plate is smaller than the length of the opposite side of the bolt head;

[0023] When the anode plate is located at an end of the bolt away from the bolt head, the diameter of the anode plate is smaller than the diameter of the inscribed circle of the end face of the bolt tail.

[0024] Furthermore, an anti-corrosion layer is provided on the surface of the fastener.

[0025] Furthermore, the fastener is made of anti-corrosion material.

[0026] Furthermore, the fastener is one of a bolt, a screw, and a rivet.

[0027] Furthermore, the cylindrical cavity is provided with an opening at least at one end of the fastener.

[0028] A second aspect of the present invention provides an anti-corrosion fastener obtained based on the anti-corrosion fastener manufacturing method as described in the first aspect.

[0029] Compared with the prior art, the method for manufacturing an anti-corrosion fastener according to the present invention has the following beneficial effects:

[0030] The present invention discloses a method for manufacturing an anti-corrosion fastener, in which a cylindrical cavity is provided in the fastener and an anode column made of an anode material filled in the cylindrical cavity is first corroded when the fastener is in a corrosive environment. The fastener is protected from corrosion by sacrificing the anode material, and the anode column is installed in the cylindrical cavity. By calculating the cross-sectional area of ​​the cylindrical cavity, the structural strength of the fastener is ensured without increasing the volume of the fastener. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0032] Figure 1 It is a schematic diagram of the cross-sectional structure of bolts with different opening forms of the cylindrical cavity according to the embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the cross-sectional structure of bolts with openings on both sides of a cylindrical cavity according to an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of the cross-sectional structure of a bolt with an anode plate disposed on the bolt head according to an embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram of the cross-sectional structure of a bolt with an anode plate disposed at the end of the bolt according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0039] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0040] Embodiment 1:

[0041] A method for manufacturing an anti-corrosion fastener,

[0042] A cylindrical cavity is provided in the fastener, and an anode column made of an anode material is arranged in the cylindrical cavity;

[0043] The galvanic sequence of the anode material is lower than the galvanic sequence of the material the fastener is made of;

[0044] Determine the maximum cross-sectional area of ​​the cylindrical cavity according to the diameter of the fastener;

[0045] Determine the minimum cross-sectional area of ​​the cylindrical cavity based on the target service life and fastener length.

[0046] The anode material includes but is not limited to aluminum, zinc, aluminum-zinc-indium alloy, aluminum-zinc-magnesium alloy, aluminum-zinc-tin alloy, etc.

[0047] In some embodiments, there are multiple anode columns in the cavity, the multiple anode columns are in close contact with each other, and the multiple anode columns are made of different anode materials. The galvanic sequence of the anode materials from the open end of the cavity to the inner side decreases successively to achieve progressive corrosion protection.

[0048] In some embodiments, the cylindrical cavities, each of which is provided with a different anode material to produce an anode column, can achieve a longer-lasting anti-corrosion effect.

[0049] The choice of anode material is related to the environment it is facing. In seawater environment, the anode material should have sufficient corrosion resistance and a lower galvanic sequence than the cathode material to provide effective protection throughout the entire service life. In freshwater environment, the anode material should have an extremely low galvanic sequence to ensure the smooth progress of the electrochemical reaction.

[0050] The fastener is one of bolts, screws and rivets, and the bolt is taken as an example below.

[0051] When the core area of ​​the bolt is filled with metal material, the static load-bearing performance of the bolt will not be significantly reduced compared with bolts of the same specification. However, as the anode column is consumed, the bolt will gradually become a hollow bolt. If the external load exceeds the ultimate load-bearing capacity of the bolt at this time, it will cause the bolt to break and the structure to fail. Therefore, it is necessary to consider the load-bearing performance of the hollow bolt without anode material to determine the maximum hole diameter. Figure 2 The figure shows the overall cross-section of the through-hole filling bolt, s is the length of the opposite side of the hexagonal bolt head, d is fil is the diameter of the anode column, and d is the nominal diameter of the bolt.

[0052] After eliminating the influence of structural size and friction coefficient dispersion, the current bolt assembly torque in my country usually does not exceed 80% of the maximum assembly utilization factor (the ratio of the bolt's design limit load to the material's limit load), while the recommended utilization factor of European design guidelines such as VDI 2230 is 90%, and in extreme cases does not exceed 95%. Therefore, in order to ensure that the preload and connection stiffness of the hollow bolt are consistent with those of the solid bolt, the removal of the core material shall not exceed 18.75% of the equivalent stress cross-sectional area.

[0053]

[0054] Therefore, the diameter of the hollow cylinder must satisfy:

[0055]

[0056] According to the Mechanical Design Manual;

[0057]

[0058] The cylindrical cavity is a cylindrical cavity, and the cylindrical cavity is arranged coaxially with the bolt. The maximum diameter calculation formula of the cylindrical cavity is:

[0059]

[0060] Among them, dfil is the maximum diameter of the cylindrical cavity, d is the nominal diameter of the bolt, and P is the pitch of the bolt.

[0061] The cylindrical cavity is a cylindrical cavity, which is coaxial with the bolt. The cylindrical cavity has openings at both ends of the bolt. The geometric shape of the anode column is regular, so the corrosion rate of the anode column will be more uniform. The corrosion rate of metals in the marine environment is usually expressed as the mass loss per unit surface area. Taking the corrosion of aluminum alloy in a typical marine environment as an example, it is usually 2.7-3.5kg / m 2 / year. Therefore, it is necessary to calculate the surface area and volume of the anode material to calculate the corrosion protection time.

[0062] The exposed surfaces of the anode material are the two end surfaces, with a surface area of ​​Aa.

[0063]

[0064] In a typical seawater environment, the mass loss due to corrosion is

[0065] m year =v cor ×A a ;

[0066] Assuming that the anode needs to be protected against corrosion for t years, the total mass loss during the t-year life is

[0067] m total =m year ×t;

[0068] M total Convert to diameter d fil ,

[0069]

[0070] In order to ensure that the anode material is not completely corroded within the service life t, the remaining mass m final Should meet

[0071] m final =m0-m total ;

[0072] and

[0073]

[0074] In the formula, the length of the anode material is ha, which is equal to the bolt length + bolt head thickness. It should be noted that the bolt length specified in the bolt standard usually does not include the bolt head thickness, which needs to be added separately.

[0075] h a =hhead +h bolt ;

[0076] The minimum diameter of a cylindrical cavity is calculated as:

[0077]

[0078] d fil,min is the minimum diameter of the cylindrical cavity, m total is the corrosion quality of the designed service life, ρ is the density of the anode material, h head is the length of the bolt, h bolt is the bolt head length of the bolt.

[0079] In a typical seawater environment, the corrosion rate is assumed to be 3.0 kg / m 2 / year, the required anti-corrosion time is 20 years, assuming that the anode material is aluminum alloy, its density is 2.7g / cm 3 , the anode material is a cylinder, the total length is 70mm, and the filling diameter is 5mm, then the total mass is:

[0080]

[0081] The total mass loss caused by corrosion over 20 years is:

[0082]

[0083] m0>m total ;

[0084] Therefore, under this parameter, the anode material can corrode for 20 years.

[0085] When the maximum cross-sectional area of ​​the cylindrical cavity is greater than the minimum cross-sectional area of ​​the cylindrical cavity, the area between the maximum cross-sectional area of ​​the cylindrical cavity and the minimum cross-sectional area of ​​the cylindrical cavity is selected as the cross-sectional area of ​​the cylindrical cavity; when the maximum cross-sectional area of ​​the cylindrical cavity is 5mm 2 , the minimum cross-sectional area of ​​the cylindrical cavity is 4mm 2 , then the cross-sectional area of ​​the cylindrical cavity can be 4mm 2 -5mm 2 Choose between the two, refer to the difficulty of opening the hole and the manufacturing cost of the anode column, and round up or select the smallest cross-sectional area.

[0086] When the maximum cross-sectional area of ​​the cylindrical cavity is smaller than the minimum cross-sectional area of ​​the cylindrical cavity, the maximum cross-sectional area of ​​the cylindrical cavity is used as the cross-sectional area of ​​the cylindrical cavity, and anode plates made of anode material are arranged at both ends of the anode column; the sum of the mass of the anode plates and the mass of the anode column is greater than the corrosion mass of the designed service life.

[0087] The anode plate is a circular plate; when the anode plate is located at one end of the bolt head, the diameter of the anode plate is smaller than the length of the opposite side of the bolt head (such as Figure 3 As shown, Figure 3 Figure a is a stereogram, and Figure b is a cross-sectional diagram); when the anode plate is located at the end of the bolt away from the bolt head, the diameter of the anode plate is smaller than the diameter of the inscribed circle of the bolt tail end face (such as Figure 4 As shown, Figure 4 Figure a is a stereogram, and figure b is a cross-sectional view).

[0088] The surface of the fastener is provided with an anti-corrosion layer.

[0089] The inner and outer surfaces of the bolts are coated with a layer of anti-corrosion coating made of cathode material to ensure that the bolts still have anti-corrosion properties even when the anode material is consumed and become ordinary plated bolts.

[0090] The cathode material must meet the following three points:

[0091] The cathode material needs to have a high galvanic order to provide adequate protection;

[0092] The cathode material must have strong corrosion resistance itself and can be used as an anti-corrosion coating alone even without the protection of a sacrificial anode;

[0093] The cathode material coating needs to be dense enough and have high bonding strength, and the mechanical properties of the bolt, such as strength and hardness, need to be maintained to ensure that the coating does not fall off and the substrate is not exposed when the bolt is subjected to wear, impact, etc., and becomes a new corrosion point.

[0094] Preferred cathode materials include nickel, titanium, nickel-based alloys (such as Inconel), cobalt-based alloys (such as Stellite alloy), tantalum, chromium alloys or highly corrosion-resistant polymer coatings.

[0095] According to the selected cathode material, appropriate coating processes are adopted, including chemical plating, electroplating, physical vapor deposition (PVD), electrochemical deposition (CVD), thermal spraying, etc., to ensure the uniformity and adhesion of the coating.

[0096] The same plating process should be selected for the nut and the bolt. After assembly, the outer surface of the nut and the bolt are connected to form a protected cathode area together.

[0097] Fasteners are made of anti-corrosion materials. Bolts are made of anti-corrosion materials (such as stainless steel or nickel-based alloys), providing triple anti-corrosion protection, that is, the anode material protects the cathode coating, the cathode coating protects the bolt substrate, and the bolt substrate itself has anti-corrosion properties.

[0098] The cylindrical cavity has an opening (such as Figure 1As shown, the fastener is a bolt, and Figure a shows that the cylindrical cavity is open at both ends of the bolt, Figure b shows that the cylindrical cavity is open at the end of the bolt away from the bolt head, and Figure c shows that the cylindrical cavity is open at the bolt head end of the bolt). During actual use, at least one opening is in contact with the corrosive liquid (seawater).

[0099] Production method:

[0100] S1. The bolt body is manufactured according to the design dimensions, and a hole is punched at the bolt axis position to form a cylindrical cavity. The punching process can be performed before or after the heat treatment process;

[0101] The cylindrical cavity can be made by punching or by mold casting.

[0102] S2. Perform cathode plating treatment on the inner and outer surfaces of the bolts, select appropriate cathode materials, and adopt appropriate plating processes to ensure that the plating is uniform, dense and has good adhesion;

[0103] S3. Fill the anode material into the hollow area of ​​the bolt core to form an anode column, which is in contact with the inner wall of the cylindrical cavity.

[0104] The anode material is filled into the hollow area of ​​the bolt core to form the anode column. The anode column can be prepared by inserting it, or the molten anode material can be poured into the cylindrical cavity to form the anode column.

[0105] S4. Manufacture the nut body according to the design dimensions and use the same cathode material and process as the bolt for coating to ensure that the coating is uniform, dense and has good adhesion.

[0106] In some embodiments, the bolts are made of anti-corrosion materials, and no anti-corrosion layer is provided on the surface of the bolts, forming double corrosion protection with the anode column; if the bolt substrate is made of stainless steel, nickel-based alloy, etc., it is optional not to add a cathode coating, because the substrate itself can become the cathode material and is protected by the anti-corrosion of the core anode material. In this case, the double corrosion protection effect can also be achieved, and the manufacturing process is simplified, reducing the manufacturing cost of the bolts.

[0107] In some embodiments, the bolts are made of ordinary non-corrosion-resistant materials, and an anti-corrosion layer is provided on the surface of the bolts to form a double anti-corrosion with the anode column;

[0108] In some embodiments, the bolts are made of anti-corrosion material, and an anti-corrosion layer is provided on the surface of the bolts to form triple corrosion protection with the anode column.

[0109] Bolts made of titanium alloy, stainless steel or coated materials are prone to seizure during assembly and disassembly, and need to be used with grease (such as MoS2 grease). Otherwise, the coating will be quickly destroyed during tightening and loosening, resulting in a poorer anti-corrosion effect. The grease also needs to be conductive, because the nut itself does not have anode material, and insulating grease will prevent current from passing between the nut and the bolt, and the nut will not be protected by the anode material.

[0110] The following table provides a recommended table of coating materials, anode materials, and bolt base materials used to manufacture multi-corrosion resistant bolts in the present invention.

[0111] Table 1 Recommended material selection for multi-corrosion resistant bolts

[0112]

[0113] Beneficial effects:

[0114] Anode material provides primary protection: the anode material (such as aluminum or zinc) filled in the bolt core is corroded first, and the bolt base material and cathode coating are protected from corrosion by sacrificing the anode material. The anode column is installed in the cylindrical cavity, and the cross-sectional area of ​​the cylindrical cavity is calculated, which not only ensures the structural strength of the fastener, but also does not increase the volume of the fastener.

[0115] Cathodic coating provides secondary protection: when the anode material is completely corroded, the cathodic coating (such as nickel and nickel-based alloys, titanium and titanium alloys, etc.) continues to provide corrosion protection, significantly extending the service life of the bolt.

[0116] Triple anti-corrosion: If the bolt substrate itself is made of anti-corrosion materials (such as stainless steel or nickel-based alloy), then on the basis of the anode material and cathode coating, the bolt substrate itself also provides anti-corrosion protection, further enhancing the anti-corrosion effect.

[0117] Resistance to mechanical damage: The design of the present invention ensures that even if the bolt surface is mechanically damaged during installation and use, the built-in anode material can still provide primary anti-corrosion protection for the substrate material with a higher galvanic sequence, avoiding the problem of easy damage to traditional anti-corrosion coatings.

[0118] Stable anti-corrosion performance: The double or even triple anti-corrosion mechanism ensures that the bolts maintain stable anti-corrosion performance throughout the entire service life, overcoming the shortcomings of the existing technology of single anti-corrosion means and poor anti-corrosion performance.

[0119] Reduce maintenance costs and frequency:

[0120] Prolong service life: Since the bolts of the present invention have significant anti-corrosion performance, they can remain in good condition for a long time in a highly corrosive environment, reducing the frequency of bolt replacement and maintenance.

[0121] Reduce downtime: Reliable anti-corrosion performance reduces equipment shutdown and repairs caused by bolt corrosion, significantly reduces maintenance costs and downtime, and improves the overall project operation efficiency.

[0122] Embodiment 2:

[0123] An anti-corrosion fastener obtained based on the anti-corrosion fastener manufacturing method as described in Example 1.

[0124] The present invention is described in detail with reference to the foregoing embodiments, but the ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or replace some or all of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

[0125] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for manufacturing an anti-corrosion fastener, characterized in that: A cylindrical cavity is provided in the fastener, and an anode column made of an anode material is arranged in the cylindrical cavity; The galvanic sequence of the anode material is lower than the galvanic sequence of the material of which the fastener is made; Determine the maximum cross-sectional area of ​​the cylindrical cavity according to the diameter of the fastener; Determine the minimum cross-sectional area of ​​the cylindrical cavity based on the target service life and fastener length.

2. The method for manufacturing an anti-corrosion fastener according to claim 1, characterized in that: The fastener is a bolt, the cylindrical cavity is a cylindrical cavity, and the maximum diameter calculation formula of the cylindrical cavity is: Among them, d fil is the maximum diameter of the cylindrical cavity, d is the nominal diameter of the bolt, and P is the pitch of the bolt.

3. The method for manufacturing an anti-corrosion fastener according to claim 1, characterized in that: The fastener is a bolt, the cylindrical cavity is a cylindrical cavity, the cylindrical cavity is coaxially arranged with the bolt, the cylindrical cavity is provided with openings at both ends of the bolt, and the minimum diameter calculation formula of the cylindrical cavity is: d fil,min is the minimum diameter of the cylindrical cavity, m total is the corrosion quality of the designed service life, ρ is the density of the anode material, h head is the length of the bolt, h bolt is the bolt head length of the bolt.

4. The method for manufacturing an anti-corrosion fastener according to claim 3, characterized in that: When the maximum cross-sectional area of ​​the cylindrical cavity is greater than the minimum cross-sectional area of ​​the cylindrical cavity, the area between the maximum cross-sectional area of ​​the cylindrical cavity and the minimum cross-sectional area of ​​the cylindrical cavity is selected as the cross-sectional area of ​​the cylindrical cavity; When the maximum cross-sectional area of ​​the cylindrical cavity is smaller than the minimum cross-sectional area of ​​the cylindrical cavity, the maximum cross-sectional area of ​​the cylindrical cavity is used as the cross-sectional area of ​​the cylindrical cavity, and anode plates made of anode materials are arranged at both ends of the anode column; The sum of the mass of the anode plate and the mass of the anode column is greater than the corrosion mass of the designed service life.

5. The method for manufacturing an anti-corrosion fastener according to claim 4, characterized in that: The anode plate is a circular plate; When the anode plate is located at the bolt head end of the bolt, the diameter of the anode plate is smaller than the length of the opposite side of the bolt head; When the anode plate is located at an end of the bolt away from the bolt head, the diameter of the anode plate is smaller than the diameter of the inscribed circle of the end face of the bolt tail.

6. The method for manufacturing an anti-corrosion fastener according to claim 1, characterized in that: An anti-corrosion layer is provided on the surface of the fastener.

7. The method for manufacturing an anti-corrosion fastener according to claim 1, characterized in that: The fastener is made of anti-corrosion material.

8. The method for manufacturing an anti-corrosion fastener according to claim 1, characterized in that: The fastener is one of a bolt, a screw and a rivet.

9. The method for manufacturing an anti-corrosion fastener according to claim 1, characterized in that: The cylindrical cavity is provided with an opening at least at one end of the fastener.

10. An anti-corrosion fastener obtained based on the anti-corrosion fastener manufacturing method according to any one of claims 1 to 9.

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