Manufacturing method of four-way body with high impact resistance and corrosion resistance for fracturing

Abstract

The invention discloses a manufacturing method of a four-way body with high impact resistance and corrosion resistance for fracturing. The manufacturing method comprises the following steps: S1, preparing a four-way body raw material blank; s2, roughing the four-way body blank, and performing heat treatment; s3, another vertical center channel I of the four-way body is drilled; s4, the four-way body is fixed to a lathe, the center channel I is subjected to finish turning, the center channel II is subjected to finish turning, and the intersection of the center channels is subjected to finish turning to form a chambering hole III; s5, a large fillet IV at the intersection of the center channel is ground; s6, cleaning and drying the four-way body; s7, HVOF equipment is used for conducting thermal spraying tungsten carbide hardening treatment on the inner surface V of the intersection of the center channels of the four-way body; s8, performing finish machining on six surfaces of the four-way body, performing finish turning on the backing ring groove, and drilling four end face screw planting holes connected with the central channel hole; according to the invention, the flow channel intersection adopts a channel reaming structure design, so that the flow channel is optimized, the fluid naturally circulates, the hindering impact is reduced, the turbulent flow degree of the fluid at the central channel intersection is conveniently reduced, and the flow loss of the main flow channel is reduced.

Description

Technical Field

[0001] The invention relates to the fields of oil and gas production such as wellhead Christmas trees and fracturing manifolds, and in particular to a method for manufacturing a high impact-resistant and corrosion-resistant quadrilateral for fracturing. Background Art

[0002] In the oil and gas production fields such as wellhead Christmas trees and fracturing manifolds, quadrilaterals are an indispensable part. Due to the high flow, high pressure, and high sand content in oil and gas production operations, in actual use, traditional quadrilaterals often suffer from internal flow channel erosion, corrosion, and other damage, resulting in abnormal flow and quadrilateral leakage, posing a great safety hazard.

[0003] After the quadrilateral is damaged, on-site maintenance is cumbersome and inefficient, affecting the progress of on-site oil and gas production operations. Therefore, in order to solve this series of problems, we proposed a method for manufacturing a high impact-resistant and corrosion-resistant quadrilateral for fracturing to solve the problem. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for manufacturing a high impact-resistant and corrosion-resistant quadrilateral for fracturing. The main channel of the quadrilateral adopts a hole expansion structure design at the intersection of the flow channels, which is convenient for the fluid to reduce the degree of turbulence at the intersection of the central channel, reduce the flow loss of the main channel, and fully meet the high flow fluid passability under the conditions of oil production trees, fracturing manifolds, etc. The intersection of the central channel of the quadrilateral adopts a large fillet structure design to reduce the impact of the fluid on the intersection of the central channel. The surface of the intersection of the flow channels is hardened by a supersonic flame spraying (HVOF) tungsten carbide process to make it have high impact resistance and corrosion resistance.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for manufacturing a high impact-resistant and corrosion-resistant quadruple for fracturing, comprising the following steps:

[0006] S1, prepare a four-piece raw material blank;

[0007] S2, roughing and heat treatment of the four-piece blank;

[0008] S3, drilling another vertical center channel I of the quadrilateral;

[0009] S4, fix the quadrilateral to the lathe, and fine-turn the center channel I, fine-turn the center channel II, and expand the hole III at the intersection of the center channel;

[0010] S5, grinding the large radius corner IV at the intersection of the center channel;

[0011] S6, cleaning and drying the tetrahedron;

[0012] S7, using HVOF equipment to perform thermal spraying tungsten carbide hardening treatment on the inner surface V of the intersection of the central channel of the quad body;

[0013] S8, fine-machining the six faces of the quadrilateral, fine-machining the gasket ring groove and drilling the four end face threading holes connected to the center channel hole;

[0014] S9. Check and print the label.

[0015] Preferably, in step S1, the raw material blank of the tetrahedron is a forged low-carbon steel alloy block.

[0016] Preferably, in step S2, the four-way body blank is roughed by using a machine tool to rough turn six sides of the raw material blank, and a 3-5mm finishing allowance is reserved on one side. A channel center through hole is drilled at the center position of one of the planes using a drilling machine, and then the center hole is processed using a boring machine, so that a 3-5mm finishing allowance is reserved on one side of the center hole. The four-way body is roughed and heat treated to meet the mechanical property requirements of the material.

[0017] Preferably, in step S3, drilling another vertical center channel I of the quad body is to roughen the quad body and fix it to a drilling machine, and drill another center channel I of the quad body, completely through it, perpendicular to the end face and the existing center channel hole.

[0018] Preferably, the roughness of the fine turning center channel I, the fine turning center channel II, and the expanded hole III at the intersection of the fine turning center channels in step S4 is controlled at Ra6.3. The expanded hole at the intersection III of the center channel of the four-way body is convenient for reducing the degree of turbulence of the fluid at the intersection of the center channels and reducing the impact of the fluid on the intersection of the center channels. The roughness is controlled at Ra6.3 to facilitate the adsorption of tungsten carbide during thermal spray tungsten carbide hardening treatment.

[0019] Preferably, in step S5, a large rounded corner IV is polished at the intersection of the central channels to reduce the impact of the fluid on the intersection of the central channels.

[0020] Preferably, in S6, the quad body is cleaned and dried, and the inner surface V at the intersection of the central channels of the quad body is not pickled, phosphated or nitrided, which is not conducive to the thermal spray tungsten carbide hardening treatment.

[0021] Preferably, in S7, using HVOF equipment to perform thermal spraying tungsten carbide hardening treatment on the inner surface V at the intersection of the central channel of the quad body, comprises the following steps:

[0022] S701, Tungsten carbide hardening coating requirements: Applicable to the use environment with the highest temperature up to 540℃. The surface tungsten carbide thermal spraying should meet the characteristics requirements shown in Table 1 and Table 2. The characteristics in Table 1 should not be applied to the substrate and the joint between the substrate and the coating.

[0023] Table 1 Chemical composition:

[0024]

[0025] The chemical composition ratio should be expressed as weight percentage (WC-CO-GR / 86-10-4)

[0026] Table 2 Coating properties:

[0027]

[0028] S702, Surface treatment requirements before tungsten carbide hardening: All surfaces to be sprayed should be free of dust, grease contaminants and adhesive oxide film. Use white corundum abrasive to sandblast and clean to Sa3 (ISO8501-1). If oxidation occurs during sandblasting and thermal spraying, the surface should be re-sandblasted to the specified visual standard. The roughness of the surface to be sprayed should be Ra6.3. If necessary, self-fluxing alloy material (nickel-clad aluminum 95% Ni-5% Al) can be sprayed on the substrate surface as a base roughening surface. Any non-sprayed surface should be shielded and properly protected.

[0029] S703, tungsten carbide hardening inspection and testing: sampling should be carried out according to the regulations for non-destructive and destructive testing. A test plate should be prepared with the same material and the same spraying process. This test plate can represent the sprayed workpiece for relevant tests. The coating surface should be visually inspected. The coating surface color should be consistent, the coating thickness should be uniform, the appearance should be smooth and flat, and no coating peeling is allowed. There should be no defects such as pores, slag inclusions, cracks, and pinholes. After machining, the coating thickness is inspected. It should be inspected by magnetic method or cross-section metallographic microscopy method according to the requirements described in ISO2178 or ISO1463. The thickness of the sprayed surface is guaranteed to be 0.20-0.34mm. After machining, the surface accuracy is inspected. The surface accuracy of the coating should meet the requirements of the drawing. The defects inside the entire coating thickness should be observed through the cross section of the sample in a 400X metallographic microscope. The coating should be continuous and amorphous, without pores and cracks. Crack / pore detection: The coating of iron-based parts should be tested for porosity using the iron reagent method. Dissolve 25g potassium ferrocyanide and 15g sodium chloride in 1L distilled water. After cleaning the parts, immerse them in the reagent solution for 30s at room temperature. Take them out, rinse them, and air dry them. Check the blue spots on the surface, which indicate the location of the pores. The porosity should be less than 1%. Bonding strength: According to ISO14916, the coating pull-off method test is carried out, and the bonding strength of the coating should be higher than 20000Psi (140MPa).

[0030] S704, Tungsten carbide hardening hardness: Coating hardness is measured according to ISO4516 Vickers microhardness measurement requirements, using a 100g load and a Vickers diamond indenter to measure the coating hardness. The test condition of HV0.1 should be used. The hardness of the coating should meet the requirements of water seal ≥1050-1250HV and air seal ≥1250-1350HV.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The base is made of forged low alloy steel material, which has good mechanical properties and mechanical properties, reducing costs;

[0033] 2. The channel intersection part adopts the channel expansion structure design to optimize the flow channel, so that the fluid can flow naturally, reduce the impact of obstacles, and reduce the degree of turbulence at the intersection of the central channel, thereby reducing the flow loss of the main channel;

[0034] 3. The intersection of the flow channels adopts a large rounded structure design to reduce the impact of the fluid on the intersection of the central channel;

[0035] 4. The surface of the flow channel intersection is hardened by high velocity oxygen flame spraying (HVOF) tungsten carbide process, making it highly impact and corrosion resistant, extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a process flow chart of a method for manufacturing a high impact-resistant and corrosion-resistant quadruple for fracturing according to the present invention;

[0037] Figure 2 A schematic diagram of a low carbon steel alloy block forged according to the present invention as a raw material blank;

[0038] Figure 3 This is a schematic diagram of the tetrahedron of the present invention after roughening;

[0039] Figure 4 This is a schematic diagram of another vertical central channel I of the quadruple body after drilling in the present invention;

[0040] Figure 5 It is a schematic diagram of the fine turning center channel I, the fine turning center channel II, and the expanded hole III at the intersection of the fine turning center channel of the present invention;

[0041] Figure 6 It is a schematic diagram of the present invention after grinding the fillet IV at the intersection of the central channel;

[0042] Figure 7 This is a schematic diagram of the present invention using HVOF equipment to perform thermal spraying tungsten carbide hardening treatment on the inner surface V at the intersection of the central channel of the quad body;

[0043] Figure 8It is a schematic diagram of the present invention after finishing six faces of the quad body, finishing the gasket ring groove, and drilling four end face threading holes connected to the center channel. DETAILED DESCRIPTION

[0044] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0045] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0046] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The phrase "in a preferred embodiment" that appears in different places in this specification does not refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0047] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0048] Example 1

[0049] See also Figure 1-8 The present invention provides a technical solution: a technical solution for manufacturing a high impact-resistant and corrosion-resistant quadruple for fracturing, comprising the following steps:

[0050] S1, prepare a four-piece raw material blank;

[0051] S2, roughing and heat treatment of the four-piece blank;

[0052] S3, drilling another vertical center channel I of the quadrilateral;

[0053] S4, fix the quadrilateral to the lathe, and fine-turn the center channel I, fine-turn the center channel II, and expand the hole III at the intersection of the center channel;

[0054] S5, grinding the large radius corner IV at the intersection of the center channel;

[0055] S6, cleaning and drying the tetrahedron;

[0056] S7, using HVOF equipment to perform thermal spraying tungsten carbide hardening treatment on the inner surface V of the intersection of the central channel of the quad body;

[0057] S8, fine-machining the six faces of the quadrilateral, fine-machining the gasket ring groove and drilling the four end face threading holes connected to the center channel hole;

[0058] S9. Check and print the label.

[0059] Example 2

[0060] like Figure 2 As shown, this embodiment provides a method for manufacturing a high impact-resistant and corrosion-resistant quadrilateral for fracturing, wherein a forged low-carbon steel alloy block is used as a raw material blank.

[0061] Example 3

[0062] like Figure 3 As shown, this embodiment provides a method for manufacturing a high impact-resistant and corrosion-resistant quadrilateral for fracturing, wherein six sides of the blank are rough-turned, and a 3-5 mm finishing allowance is reserved on one side; a center hole for a channel is drilled at the center position of one of the planes using a drilling machine, and then the center hole is processed using a boring machine, so that a 3-5 mm finishing allowance is reserved on one side of the center hole; finally, the quadrilateral is roughened and heat-treated to meet the mechanical property requirements of the material.

[0063] Example 4

[0064] like Figure 4 As shown, this embodiment provides a method for manufacturing a high impact-resistant and corrosion-resistant quadrilateral for fracturing, wherein the quadrilateral is roughened and fixed to a drilling machine, and another central channel I of the quadrilateral is drilled completely through the quadrilateral, perpendicular to the end face and the existing central channel hole.

[0065] Example 5

[0066] like Figure 5 As shown, this embodiment provides a method for manufacturing a high impact-resistant and corrosion-resistant quadrilateral for fracturing, wherein the quadrilateral is fixed to a lathe, and the center channel I, the center channel II, and the center channel intersection III are fine-turned, and the roughness is controlled at Ra6.3. The hole at the intersection III of the center channel of the quadrilateral is expanded to reduce the degree of turbulence of the fluid at the intersection of the center channels and reduce the impact of the fluid on the intersection of the center channels. The roughness is controlled at Ra6.3 to facilitate the adsorption of tungsten carbide during thermal spraying tungsten carbide hardening treatment.

[0067] Example 6

[0068] like Figure 6As shown, this embodiment provides a method for manufacturing a highly impact-resistant and corrosion-resistant quadrilateral for fracturing, wherein the large radius IV at the intersection of the central channels is polished to reduce the impact of the fluid on the intersection of the central channels, and the quadrilateral is cleaned and dried. The inner surface V at the intersection of the central channels of the quadrilateral should never be pickled, phosphated or nitrided, which is not conducive to thermal spray tungsten carbide hardening treatment.

[0069] Example 7

[0070] like Figure 7 As shown, this embodiment provides a method for manufacturing a high impact-resistant and corrosion-resistant quad body for fracturing, using HVOF equipment to perform thermal spraying tungsten carbide hardening treatment on the inner surface V at the intersection of the central channel of the quad body, including the following steps:

[0071] S701, Tungsten carbide hardening coating requirements: Applicable to the use environment with the highest temperature up to 540℃. The surface tungsten carbide thermal spraying should meet the characteristics requirements shown in Table 1 and Table 2. The characteristics in Table 1 should not be applied to the substrate and the joint between the substrate and the coating.

[0072] Table 1 Chemical composition:

[0073]

[0074] The chemical composition ratio should be expressed as weight percentage (WC-CO-GR / 86-10-4)

[0075] Table 2 Coating properties:

[0076]

[0077] S702, Surface treatment requirements before tungsten carbide hardening: All surfaces to be sprayed should be free of dust, grease contaminants and adhesive oxide film. Use white corundum abrasive to sandblast and clean to Sa3 (ISO8501-1). If oxidation occurs during sandblasting and thermal spraying, the surface should be re-sandblasted to the specified visual standard. The roughness of the surface to be sprayed should be Ra6.3. If necessary, self-fluxing alloy material (nickel-clad aluminum 95% Ni-5% Al) can be sprayed on the substrate surface as a base roughening surface. Any non-sprayed surface should be shielded and properly protected.

[0078] S703, tungsten carbide hardening inspection and testing: sampling should be carried out according to the regulations for non-destructive and destructive testing. A test plate should be prepared with the same material and the same spraying process. This test plate can represent the sprayed workpiece for relevant tests. The coating surface should be visually inspected. The coating surface color should be consistent, the coating thickness should be uniform, the appearance should be smooth and flat, and no coating peeling is allowed. There should be no defects such as pores, slag inclusions, cracks, and pinholes. After machining, the coating thickness is inspected. It should be inspected by magnetic method or cross-section metallographic microscopy method according to the requirements described in ISO2178 or ISO1463. The thickness of the sprayed surface is guaranteed to be 0.20-0.34mm. After machining, the surface accuracy is inspected. The surface accuracy of the coating should meet the requirements of the drawing. The defects inside the entire coating thickness should be observed through the cross section of the sample in a 400X metallographic microscope. The coating should be continuous and amorphous, without pores and cracks. Crack / pore detection: The coating of iron-based parts should be tested for porosity using the iron reagent method. Dissolve 25g potassium ferrocyanide and 15g sodium chloride in 1L distilled water. After cleaning the parts, immerse them in the reagent solution for 30s at room temperature. Take them out, rinse them, and air dry them. Check the blue spots on the surface, which indicate the location of the pores. The porosity should be less than 1%. Bonding strength: According to ISO14916, the coating pull-off method test is carried out, and the bonding strength of the coating should be higher than 20000Psi (140MPa).

[0079] S704, Tungsten carbide hardening hardness: Coating hardness is measured according to ISO4516 Vickers microhardness measurement requirements, using a 100g load and a Vickers diamond indenter to measure the coating hardness. The test condition of HV0.1 should be used. The hardness of the coating should meet the requirements of water seal ≥1050-1250HV and air seal ≥1250-1350HV.

[0080] Example 8

[0081] like Figure 8 As shown, this embodiment provides a method for manufacturing a high impact-resistant and corrosion-resistant quadrilateral for fracturing, which includes fine-machining the six faces of the quadrilateral, fine-machining the gasket ring groove, drilling four end face threading holes connected to the center channel, and inspecting and printing the identification.

[0082] In summary: the main channel of the quadruple body of the invention adopts an expanded hole structure design at the intersection of the flow channels, which is convenient for the fluid to reduce the degree of turbulence at the intersection of the central channel and reduce the flow loss of the main channel, fully meeting the high-flow fluid passability under conditions such as Christmas trees and fracturing manifolds. The intersection of the central channel of the quadruple body adopts a large fillet structure design to reduce the impact of the fluid on the intersection of the central channel. The surface of the intersection of the flow channels is hardened by the supersonic flame spraying (HVOF) tungsten carbide process, making it highly impact-resistant and corrosion-resistant.

[0083] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0084] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a high impact and corrosion resistant quadrilateral for fracturing, characterized in that: The following steps are involved: S1, prepare the raw material blank of the four-piece body; S2, roughing and heat treatment of the four-piece blank; S3, drilling another vertical center channel I of the quadrilateral; S4, fix the quadrilateral to the lathe, and fine-turn the center channel I, fine-turn the center channel II, and expand the hole III at the intersection of the center channel; S5, grinding the large rounded corner IV at the intersection of the center channel; S6, cleaning and drying the tetrahedron; S7, using HVOF equipment to perform thermal spraying tungsten carbide hardening treatment on the inner surface V of the intersection of the central channel of the quad body; S8, fine-machining the six faces of the quadrilateral, fine-machining the gasket ring groove and drilling the four end face threading holes connected to the center channel hole; S9. Check and print the mark.

2. The method for manufacturing a high impact-resistant and corrosion-resistant quad body for fracturing according to claim 1, characterized in that: In the step S1, the raw material blank of the tetrahedron is a forged low-carbon steel alloy block.

3. The method for manufacturing a high impact-resistant and corrosion-resistant quad body for fracturing according to claim 1, characterized in that: In the step S2, the four-way body blank is roughed by using a machine tool to rough turn six sides of the raw material blank, and a 3-5mm finishing allowance is reserved on one side. A channel center through hole is drilled at the center position of one of the planes using a drilling machine, and then the center hole is processed using a boring machine, so that a 3-5mm finishing allowance is reserved on one side of the center hole.

4. The method for manufacturing a high impact-resistant and corrosion-resistant quad body for fracturing according to claim 1, characterized in that: In step S3, drilling another vertical center channel I of the quad body is to roughen the quad body and fix it to the drilling machine, and drill another center channel I of the quad body, completely through it, perpendicular to the end face and the existing center channel hole.

5. The method for manufacturing a high impact-resistant and corrosion-resistant quad body for fracturing according to claim 1, characterized in that: In the step S4, the roughness of the fine turning center channel I, the fine turning center channel II, and the expanded hole III at the intersection of the fine turning center channels is controlled to be Ra6.

3.

6. The method for manufacturing a high impact-resistant and corrosion-resistant quad body for fracturing according to claim 1, characterized in that: In step S5, the large rounded corner IV at the intersection of the central channels is polished to reduce the impact of the fluid on the intersection of the central channels.

7. The method for manufacturing a high impact-resistant and corrosion-resistant quad body for fracturing according to claim 1, characterized in that: In step S6, the quadruple body is cleaned and dried to remove the pickling, phosphating or nitriding.

8. The method for manufacturing a high impact-resistant and corrosion-resistant quad body for fracturing according to claim 1, characterized in that: In S7, the inner surface V at the intersection of the central channel of the quad body is subjected to thermal spraying tungsten carbide hardening treatment using HVOF equipment, including the following steps: S701, Tungsten carbide hardening coating preparation: suitable for use in environments with a maximum temperature of 540°C. The surface tungsten carbide thermal spraying should meet the characteristics shown in Table 1 and Table 2. The characteristics in Table 1 should not be applied to the substrate and the joint between the substrate and the coating. Table 1 Chemical composition: The chemical composition ratio should be expressed as weight percentage (WC-CO-GR / 86-10-4) Table 2 Coating properties: S702, Surface treatment before tungsten carbide hardening: All surfaces to be sprayed should be free of dust, grease contaminants and adhesive oxide film. Use white corundum abrasive to sandblast and clean to Sa3 (ISO8501-1). If oxidation occurs during sandblasting and thermal spraying, the surface should be sandblasted again to the specified visual standard. The roughness of the surface to be sprayed should be Ra6.

3. If necessary, self-fluxing alloy material (nickel-clad aluminum 95% Ni-5% Al) can be sprayed on the substrate surface as a base roughening surface. Any non-sprayed surface should be shielded and properly protected. S703, tungsten carbide hardening inspection and testing: sampling should be carried out according to the regulations for non-destructive and destructive testing. A test plate should be prepared with the same material and the same spraying process. This test plate can represent the sprayed workpiece for relevant tests. The coating surface should be visually inspected. The coating surface color should be consistent, the coating thickness should be uniform, the appearance should be smooth and flat, and no coating peeling is allowed. There should be no defects such as pores, slag inclusions, cracks, and pinholes. After machining, the coating thickness is inspected. It should be inspected by magnetic method or cross-section metallographic microscopy method according to the requirements described in ISO2178 or ISO1463. The thickness of the sprayed surface is guaranteed to be 0.20-0.34mm. After machining, the surface accuracy is inspected. The surface accuracy of the coating should meet the requirements of the drawing. The defects inside the entire coating thickness should be observed through the cross section of the sample in a 400X metallographic microscope. The coating should be continuous and amorphous, without pores and cracks. Crack / pore detection: The coating of iron-based parts should be tested for porosity using the iron reagent method. Dissolve 25g potassium ferrocyanide and 15g sodium chloride in 1L distilled water. After cleaning the parts, immerse them in the reagent solution for 30s at room temperature. Take them out, rinse them, and air dry them. Check the blue spots on the surface, which indicate the location of the pores. The porosity should be less than 1%. Bonding strength: According to ISO14916, the coating pull-off method test is carried out, and the bonding strength of the coating should be higher than 20000Psi (140MPa). S704, Tungsten carbide hardening hardness: Coating hardness is measured according to ISO4516 Vickers microhardness measurement requirements, using a 100g load and a Vickers diamond indenter to measure the coating hardness. The test condition of HV0.1 should be used. The hardness of the coating should meet the requirements of water seal ≥1050-1250HV and air seal ≥1250-1350HV.

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