Borated corrosion-resistant alloy components for high pressure high temperature oilfield applications

Abstract

This invention discloses a hardened slip component and its preparation method. Specifically, it discloses a method for surface hardening of slip components used in downhole tools. The slip component may have a bearing surface and be constructed of a metallic matrix material. The method may include the following steps: positioning at least the bearing surface of the slip component in direct contact with a boron source; bonding an outer layer to at least the bearing surface by boronizing the matrix material to form a metallurgical bond between boron from the boron source and the matrix material; and maintaining the overall temperature of the slip component below the melting point of the matrix material.

Description

Technical Field

[0001] This invention generally relates to downhole tools in the oil and gas field sector, and more specifically, to boronized or boron-dipped corrosion-resistant alloy components for high-pressure and high-temperature oilfield applications. Background Technology

[0002] Downhole tools typically use slips to engage with the casing and hold the tools in place. For example, a packer is a type of downhole tool that uses slips, primarily used to isolate different producing formations in oil and gas wells. The slips on a packer help maintain its position under high pressure, high temperature, and external forces by creating frictional resistance between the packer and the casing or wellbore. Packers and their slips can be classified into two types: permanent and retrievable.

[0003] Permanent packers are typically less expensive to manufacture and can usually withstand higher pressures and temperatures. In contrast, retrievable packers can be "unsealed" using hydraulic or mechanical means and can be retrieved from the wellbore along with the tubing or working string. Because they are designed for reusability, retrievable packers are usually more complex in structure and have more mechanical parts.

[0004] Because permanent packers are permanent, their removal typically requires destructive removal through milling or drilling. In other words, permanent packers are designed for single use and must be destroyed during removal. Therefore, using materials that are easier to mill or drill is ideal for manufacturing permanent packers. Common easily machinable materials include non-metallic materials such as composites, ceramics, and plastics. Engineering plastics such as ultra-high molecular weight polyethylene (UHMW) and polytetrafluoroethylene (PTFE) are often chosen due to their high molecular weight and long molecular chain characteristics; other thermoplastic polyethylene materials are also used.

[0005] Generally, materials that are easy to mill / drill have lower mechanical strength and relatively weaker load-bearing capacity. Conversely, while permanent packers made of high-strength metal materials can improve load-bearing capacity, the increased strength makes milling or drilling removal more difficult. Increased packer strength means more drilling time is required for removal. Therefore, there is an inherent contradiction in using permanent packers made of metal materials: when removal is needed, longer milling / drilling time is required. Given the high cost of drilling time, the additional operating costs may offset or even exceed the cost savings of using permanent packers compared to recyclable packers.

[0006] Using more durable metals can also lead to a problem called "bit tracking" when drilling or milling metals. When this occurs, the drill bit used for milling tools stays on a fixed trajectory and fails to cut the material to be drilled or milled. When this happens, the drill bit needs to be withdrawn and quickly re-engaged with the material. A small amount of debris may be generated during bit tracking, but in reality, the drill bit is simply experiencing frictional wear against the surface of the downhole tool. Essentially, during bit tracking, the drill bit continues to rotate but does not effectively cut the packer or other material to be removed. Unfortunately, this situation, where the drill bit continues to rotate without actually drilling or milling the packer or other material to be removed, may not be detected in time by surface operators.

[0007] Downhole tools are required when it is necessary to seal the casing or tubing or other pipes in the wellbore, such as when it is desired to pump cement or other mud into the formation. In this case, it is best to seal the tubing relative to the casing and prevent the fluid pressure of the mud from lifting the tubing out of the well. Packers, bridge plugs, etc., are designed for these general purposes. Sliding mechanisms are devices used on these downhole tools to contact the wellbore and hold the downhole tool within the wellbore without substantial movement, and, as mentioned above, to prevent fluid or pressure. Typically, sliding mechanisms are used to contact the wellbore to hold the downhole tool within the wellbore without substantial movement.

[0008] The requirement for slips is that they can engage or lock downhole tools; a typical example is packer slips used to anchor packers to a designated position in the casing or wellbore. The current technical challenge lies in how to remove slips more efficiently through milling or drilling techniques, thereby shortening drilling and completion cycles and reducing operating costs.

[0009] Existing slips are mostly made of gray cast iron and ductile iron. These cast irons are easier to grind / drill, but still require a significant amount of grinding / drilling time. Recently, a new type of slip has emerged, using a composite slip matrix bonded to a ceramic interlocking element. While this composite slip shows promise, it has not yet been fully validated due to potential ductility issues with the composite matrix material, and therefore, an ideal solution has not yet been developed.

[0010] Furthermore, existing technology knows of methods for forming a hardened layer on the surface of aluminum packers through anodizing. However, this is problematic because anodizing has been found to produce a very thin coating of only a few angstroms or micrometers. Because this is a relatively thin layer, the slider cannot easily adhere to the substrate.

[0011] Therefore, there is an urgent need to develop highly corrosion-resistant alloy components suitable for high-pressure, high-temperature oilfield operating environments, especially in highly corrosive environments. Standard steel has a relatively high conventional corrosion rate, which can lead to the corrosion of components such as slips, causing them to fail. Boring treatment in the oilfield field is mainly used to improve wear resistance, rather than as a hardening treatment. Summary of the Invention

[0012] In one embodiment, the present invention relates to a method for surface hardening a slip component for a downhole tool. The slip component may have a bearing surface and may be made of a base material, which is a metallic material. The method may include the steps of: positioning at least the bearing surface of the slip component in direct contact with a boron source; bonding at least an external layer to the bearing surface by boriding the base material to form a metallurgical bond between boron from the boron source and the base material; and maintaining the bulk temperature of the slip component below the melting point of the base material.

[0013] Optionally, in any embodiment, keeping the overall temperature of the slip component below the melting point includes keeping the overall temperature of the slip component below the damage temperature at the design strength level of the slip component.

[0014] Optionally, in any embodiment, the base material of the slip component includes a nickel superalloy.

[0015] Optionally, in any embodiment, the nickel superalloy includes UNS N07718.

[0016] Optionally, in any embodiment, the method further includes the step of increasing at least a portion of the hardness of the outer layer by surface-treating the outer layer to create compressive stress or release tensile stress.

[0017] Optionally, in any embodiment, the method further includes the step of improving at least a portion of the corrosion resistance of the outer layer by surface treatment.

[0018] Optionally, in any embodiment, the surface-treated outer layer includes steps using mechanical processes selected from peening, shot peening, and burnishing; or using non-mechanical processes selected from ultrasonic peening and laser peening.

[0019] Optionally, in any embodiment, the slip component includes at least one slip of the slip mechanism of the downhole tool, and wherein the bearing surface includes the clamping surface of the at least one slip.

[0020] In another embodiment, an exemplary embodiment includes a slip component for a downhole tool. The slip component is made of a metallic base material and has a bearing surface. The bearing surface of the slip component is positioned in direct contact with a boron source; and an outer layer is bonded to at least the bearing surface by boronizing the base material to form a metallurgical bond between the boron from the boron source and the base material, and the overall temperature of the slip component is maintained below the melting point of the base material.

[0021] In yet another embodiment, an exemplary embodiment includes a method for surface hardening a slip component for a downhole tool. The slip component has a bearing surface and is made of a metallic base material. The method may include the steps of: positioning at least the bearing surface of the slip component in direct contact with a boron source; bonding an outer layer at least to the bearing surface by boronizing the base material; and increasing at least a portion of the hardness of the outer layer by surface treatment to create compressive stress or release tensile stress. Attached Figure Description

[0022] The foregoing description of the invention and the following detailed description of the embodiments will be better understood when read in conjunction with the accompanying drawings. It should be understood that the depicted embodiments are not limited to the precise arrangements and means shown.

[0023] Figure 1 This is a flowchart illustrating a surface hardening method for a slip component of a downhole tool, according to one embodiment; Figure 2 This is a flowchart of a surface hardening method for a slip component for a downhole tool, described according to another embodiment; Figure 3 This is a perspective view of a machined chuck before borosilicated, according to one embodiment; Figure 4 This is a perspective view of a vacuolar component placed in boron source powder according to one embodiment; Figure 5 This is a perspective view of a boronized chuck component according to one embodiment; Figure 6 This is a perspective view of a slip component with a boronized surface in use according to one embodiment; Figure 7 Yes Figure 6 The chart shown illustrates the load test conducted on the Kawa; Figure 8Yes, a SEM image of the cross-section of the boronized sample at 10x magnification, showing thickness measurements and chemical analysis of the boxed area; and Figure 9 This is a curve showing the microhardness of the boronized sample as a function of depth. Detailed Implementation

[0024] Before describing the embodiments, terms, methods, systems, and materials have been described; it should be understood that this disclosure is not limited to the specific terms, methods, systems, and materials described, and these can vary. It should also be understood that the terminology used in this specification is only for describing a particular version of the embodiments and is not intended to limit the scope of the embodiments. For example, unless the context clearly specifies otherwise, the singular forms “a,” “an,” and “the” as used herein include plural references. Furthermore, the word “comprising” as used herein is intended to mean “including, but not limited to,” “including.” Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

[0025] Unless otherwise stated, all figures used in the specification and claims to indicate the amount of components, properties (e.g., size, weight, reaction conditions, etc.) should be understood to be modified by the term "about" in all cases. Therefore, unless otherwise indicated, the numerical parameters listed in the following specification and claims are approximate values ​​that may vary according to the desired properties obtained according to the invention. At least, and without attempting to limit the application of the doctrine of equivalence to the scope of the claims, each numerical parameter should be interpreted at least according to the number of significant figures reported and by applying ordinary rounding techniques.

[0026] As used in this article, the term “about” refers to a numerical value that is added to or subtracted by 10% when used with it. Therefore, about 50% means in the range of 45% to 55%.

[0027] A slip component for a downhole tool has a surface-hardened bearing surface. The slip component can be a slip or other part of a slip mechanism used on packers, bridge plugs, or other downhole tools. In fact, the slip component can be a slip, cone, and / or cage of a downhole tool's slip mechanism, and may even include a portion of the downhole tool's mandrel adjacent to the slip structure. In any case, the slip component is made of a metallic matrix material with a relatively low melting point compared to steel. For example, the metallic matrix material of the slip component can be magnesium, aluminum, aluminum alloys, nickel superalloys, or magnesium alloys. In particular, the nickel superalloy can be a series of nickel alloys, such as UNS N07718.

[0028] To perform surface hardening on the slip components, at least the bearing surface of the slip components is positioned in direct contact with the boron source. The bearing surface can be the gripping surface of slips used to engage downhole fittings, but any bearing surface subjected to wear, friction, etc., can benefit from the disclosed technology.

[0029] The hardness of at least a portion of the outer layer can be further increased by surface treatment of the outer layer to generate compressive stress or release tensile stress. For example, surface treatment of the outer layer can involve the use of mechanical processes such as shot peening, shot blasting and polishing, or it can involve the use of non-mechanical processes such as ultrasonic shot peening and laser shot peening.

[0030] like Figure 1 As shown, this invention discloses a method 100 for surface hardening of slip components of a downhole tool. The slip component may have a bearing surface and be made of a base material, which is a metallic material, such as a nickel superalloy. Method 100 may include the following steps: in step 120, positioning at least the bearing surface of the slip component in direct contact with a boron source; in step 140, bonding at least an outer layer to the bearing surface by boronizing the base material, thereby forming a metallurgical bond between boron from the boron source and the base material; and in step 160, maintaining the overall temperature of the slip component at the melting point of the base material.

[0031] In one embodiment, step 160, which involves maintaining the overall temperature of the slip component below its melting point, may include maintaining the overall temperature of the slip component below a damage temperature below the design strength level of the slip component. In one embodiment, the nickel superalloy may include UNS N07718.

[0032] In one embodiment, method 100 may further include the step of increasing at least a portion of the hardness of the outer layer by performing a surface treatment on the outer layer to generate compressive stress or release tensile stress.

[0033] In one embodiment, method 100 may further include the step of improving at least a portion of the corrosion resistance of the outer layer by performing a surface treatment on the outer layer.

[0034] In one embodiment, the surface-treated outer layer may include a mechanical process selected from shot peening, shot blasting and polishing; or a non-mechanical process selected from ultrasonic shot peening and laser shot peening.

[0035] In one embodiment, the slip component includes at least one slip of a slip mechanism for a downhole tool, and the slip has a clamping surface that serves as the bearing surface.

[0036] In another embodiment, the present invention relates to a method 200 for surface hardening a slip component for a downhole tool, the method comprising the steps of: in step 220, positioning at least a bearing surface of the slip component in direct contact with a boron source; in step 240, bonding an outer layer to at least the bearing surface by boronizing a base material; and in step 260, increasing at least a portion of the hardness of the outer layer by surface treatment to create compressive stress or release tensile stress.

[0037] like Figure 3 As shown, a slip component machined from UNS N07718 is placed in a fixture to shield the inner surface from borosilicated treatment. Only the outer diameter profile of the component needs to be hardened to allow it to engage with the casing. The slip component 300 for downhole tools can be made of a base material such as Inconel 718 superalloy and has a bearing surface 310. The base material is a metallic material, including nickel superalloys such as UNS N07718. Nickel superalloys include nickel-chromium alloys with significant amounts of iron, niobium, and molybdenum, and smaller amounts of aluminum and titanium.

[0038] The chemical composition of the Inconel 718 superalloy is as follows (all in weight %): Cr 19.0, Ni 52.4, Mo 3.0, Nb 5.1, Ti 0.9, Al 0.5, Fe 18.5, C maximum 0.08, Cu maximum 0.15.

[0039] like Figure 4 As shown, prior to processing, both slips are embedded in boron powder. The components are completely immersed in the powder to ensure complete boronization of the contours. At least the bearing surface 310 of the slip component 400 can be treated by: positioning the bearing surface 310 of the slip component 400 in direct contact with the boron source 420; and by boronizing the base material to bond at least an outer layer to the bearing surface, so that a metallurgical bond is formed between the boron from the boron source 420 and the base material, and by maintaining the overall temperature of the sliding component below the melting point of the base material.

[0040] The boron source may include, for example, 10% B4C, 10% KBF, and 80% SiC. The thickness of the boronizing powder mixture layers above and below the sample is 20 mm. The filled container was boronized in an electric furnace at 950 °C for 1, 2, 4, and 6 h (followed by air cooling).

[0041] For borinated samples at 950℃, the top silicide layer on the sample surface can be uniform or discontinuous, depending on the reaction between the silicon provided by SiC from the boride powder mixture and the nickel on the sample surface. During borination, two competing processes—boride formation and silicide formation—occur simultaneously. The thermodynamic conditions during borination determine whether boride growth or a mixed boride-silicide layer growth is dominant. Alloy borides can form beneath the silicide layer. This region can be further subdivided into thick needle-like boride regions and grain boundary boride regions. In the top boride region, a mixture of various borides exists. Grain boundaries are not visible in the top boride region. However, the bottom region shows borides that encase the grain boundaries and grow in the grains in a needle-like form. This bottom region is the boride diffusion front.

[0042] The hardness values ​​in the boride layer can be correlated with various borides identified based on energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and literature. EDS results confirmed the presence of Fe-, Cr-, and Ni-borides in the boride layer. The needle-like structures in the surface region of the boride layer (below the silicide layer) are iron borides and chromium borides. This region exhibits the highest microhardness values ​​(1500–2000 HV).

[0043] Boronizing mechanism at 950℃

[0044] Stage 1: Silicide formation and boron diffusion

[0045] In the boronizing process of Inconel 718 superalloy, silicide formation, boron diffusion, boride formation, and the growth of silicide and boride layers occur simultaneously. At the boronizing temperature, the activator (KBF4) decomposes to generate BF3 gas, which then reacts with boron-producing material (B4C) to generate BF2 gas. On the sample surface, SiC present in the filling mixture reacts with BF3 gas to form SiF4, and SiF4 reacts with Ni to form intermetallic compounds (silicides). The thickness of the silicide layer may increase with increasing boronizing time. In the current work, the thickness of the silicide layer is approximately 10-30 mm. The formation of each phase during the boronizing layer growth process can be inferred from the microstructure of the cross-section of the boronized sample. The microstructure formed at the interface between the boronized layer and the unboronized region may be the initial stage of boronizing. Boron has low solubility in the close-packed lattice of the γ phase, and planar defects are the easiest pathway for boron to diffuse. Therefore, boron diffusion occurs along grain boundaries and twin boundaries, where it lowers their interfacial free energy.

[0046] Stage 2: Boride Formation

[0047] Boron diffuses along grain boundaries to form alloy borides (Ni-, Cr-, and Fe-borides). Based on the Gibbs free energy, it is possible to first form Cr-borides, then Ni-borides, followed by simultaneous formation of Fe-borides and silicides. Due to the presence of SiC in the boronizing powder mixture, Si diffuses into the sample and forms Ni-Si-B compounds within the boride layer. Once boron diffusion proceeds and the boron potential increases, needle-like structures of the alloy borides begin to form within the grains, accompanied by coarsening of the grain boundary borides, with grain boundary diffusion acting as the boride diffusion front.

[0048] Third stage: Growth of borides

[0049] Over time, the boron concentration decreases along the depth gradient of the cross-section (between the surface and the substrate). This helps to increase the width and length of existing borides. The already formed chromium borides and nickel borides mix and fill the gaps between them (due to their growth) to form a thick and uniform boride layer. During this growth process, iron boride needles form in the boride layer, especially in the top region of the layer.

[0050] Figure 5 The post-boronized region of the superalloy UNS N07718 component is shown after treatment and before shot peening. Following boronizing, the cross-section of the sample was polished on an automated polishing machine. The component was then sandblasted to remove boron powder. The sample was thoroughly cleaned with soap solution, followed by thorough cleaning with acetone. Further surface treatment of the outer layer may include mechanical processes selected from shot peening, shot blasting, and polishing; or non-mechanical processes selected from ultrasonic shot peening and laser shot peening.

[0051] Surface-hardened slips can be used in high-pressure, high-temperature oilfield applications. The slips are made of boronized corrosion-resistant alloys (e.g., UNSN07718), which improve corrosion resistance in the high-temperature, high-pressure environments common in oil and gas extraction operations.

[0052] like Figure 6 As shown, the boronized slips of UNS N07718 are placed on a test fixture. A section of casing is then placed on the fixture, positioned above a large OD bottom piece. A compressive load is applied to the fixture, causing the slips to expand and contact the casing. Slip 600 is designed to act as an anchor for the completion packer 660 within the casing (not shown). The slips are made of a boronized corrosion-resistant alloy, providing enhanced corrosion resistance in high-temperature and high-pressure environments. The boronizing process enhances the alloy's corrosion resistance by forming a hard, wear-resistant surface layer that provides enhanced corrosion and abrasion protection.

[0053] In order for the slips to penetrate the casing and secure the packer in place, the slips need to be borated to improve their corrosion resistance and wear resistance.

[0054] The slips are designed to work in conjunction with completion packers within the casing. The packer is placed inside the casing, and the slips are positioned below it. The boronized surface of the slips penetrates the casing, anchoring the packer in place. The boronized corrosion-resistant alloy provides enhanced resistance to corrosion and abrasion, ensuring the slips firmly anchor the packer even under high pressure and high temperature environments.

[0055] In one embodiment, the slip assembly may include at least one slip of a slip mechanism of a downhole tool having a gripping surface 640 as a bearing surface 620. The slip assembly may be selected from the group consisting of a downhole tool slip 600, a cone, and a cage of the slip mechanism.

[0056] like Figure 7 The test results show that the first peak indicates the load required for the slip to expand by pushing it upwards onto the cone. The second peak indicates the load at which the slip contacts and penetrates the casing. The surface-hardened slip 600 can be fitted into the packer 680 for testing and has demonstrated a set load of 32,000 psi for penetration of the casing and a contact load of 32,000 psi. Furthermore, this design utilizes boronizing to achieve a Vickers hardness greater than 50 HRC for engagement with V-140 grade casing.

[0057] A full load of 299,600 lbs was applied to the slips, and no slip movement was observed. The slips were able to maintain the load without causing expansion of the casing outer diameter. After releasing the load, the clamps were removed to inspect the tested components.

[0058] Figure 8 An attempt at a cross-sectional view of the boronized sample at 10x magnification is shown, along with thickness measurements and chemical analysis of the boxed regions, such as 1, 2, 3, and 4.

[0059] Table 1. Semi-quantitative EDS analysis of the above regions, highlighting major elements; wt.%

[0060] Figure 9 The curves showing the microhardness of the borated sample as a function of depth are presented. The Knoop hardness reaches its maximum of 2079 at a depth of approximately 10 micrometers. The hardness decreases with increasing depth.

[0061] Inconel 718 boronized chucks outperform alloy steel 8620 chucks by a significant margin. One key difference between boronized and carburized chuck tests is that Inconel 718 chucks require a higher breaking force. Alloy steel 8620 chucks fracture at 7700 pounds, while Inconel 718 chucks fracture at 32000 pounds. Both have the same fracture area.

[0062] Compared to carburized slips made of alloy steel 8620, the slips penetrate the casing to a shallower depth. The maximum penetration depth of carburized slips is approximately 0.040 inches, with the shallowest measured depth being approximately 0.010 inches. The maximum penetration depth of borated slips is approximately 0.01215 inches, with the shallowest measured depth being approximately 0.00465 inches. The borided layer depth is less than the carburized layer depth. Whether a significantly shallower depth provides sufficient hardness to penetrate the casing is not clear. The slip hardness must exceed the casing hardness by 5 HRC, while the underlying material neither deforms nor cracks. The carburized layer depth ranges from approximately 0.01 inches to approximately 0.200 inches, with a hardness exceeding approximately 60 HRC. The borided layer thickness ranges from approximately 0.0005 inches to approximately 0.001 inches, also with a hardness exceeding approximately 60 HRC. However, the underlying nickel alloy is significantly softer than the casing (approximately <41 HRC). Skilled technicians can anticipate that the casing depth is insufficient to prevent deformation of the base material, thus preventing the casing from being engaged.

[0063] The tests ultimately proved that the nickel boride alloy components were strong enough to grip even the hardest oilfield casing.

[0064] Although only a few exemplary embodiments of the invention have been described in detail above, those skilled in the art will readily understand that many modifications may be made to the exemplary embodiments without substantially departing from the novel teachings and advantages of the invention. Therefore, all such modifications are intended to be included within the scope of the invention as defined in the appended claims. In the claims, unless the term “means for…” is explicitly used along with the associated function, no clause is intended to adopt the “means + function” format permitted by paragraph 6 of 35 USC § 112. The “means for…” clause is intended to cover structures described herein that perform the mentioned function, including not only structural equivalents but also equivalent structures.

[0065] The foregoing has shown and described the basic principles, main features, and advantages of this patent application. Those skilled in the art will understand that this patent application is not limited to the embodiments described above. The foregoing embodiments and descriptions are merely preferred examples of this patent application and are not intended to limit the scope of this patent application. Various changes and modifications may be made to this patent application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed patent application. The scope of protection of this patent application is defined by the appended claims and their equivalents.

Claims

1. A method for surface hardening a slip component for a downhole tool, the slip component having a bearing surface and being made of a metallic matrix material, the method comprising: At least the bearing surface of the slip component should be positioned to be in direct contact with the boron source; By boronizing the matrix material, at least one outer layer is bonded to the bearing surface, thereby forming a metallurgical bond between the boron from the boron source and the matrix material; and The overall temperature of the valve component is maintained below the melting point of the base material.

2. The method according to claim 1, wherein, Maintaining the overall temperature of the slip component below the melting point includes maintaining the overall temperature of the slip component below the damage temperature at the design strength level of the slip component.

3. The method according to claim 1 or 2, wherein, The base material of the slip component includes a nickel superalloy.

4. The method according to claim 3, wherein, The nickel superalloy includes UNS N07718.

5. The method according to any one of claims 1-4, further comprising increasing at least a portion of the hardness of the outer layer by surface treating the outer layer to create compressive stress or release tensile stress.

6. The method according to any one of claims 1-5, further comprising improving at least a portion of the corrosion resistance of the outer layer by surface treatment of the outer layer.

7. The method according to any one of claims 1-6, wherein, The surface treatment of the outer layer includes: Use mechanical processes selected from shot peening, shot blasting, and polishing; or Use non-mechanical processes selected from ultrasonic shot peening and laser shot peening.

8. The method according to any one of claims 1-7, wherein, The slip component includes at least one slip of the slip mechanism of the downhole tool, and wherein the bearing surface includes the clamping surface of the at least one slip.

9. A slip component for a downhole tool, the slip component being made of a base material and having a bearing surface, the base material being a metallic material, and at least the bearing surface being treated in the following manner: At least the bearing surface of the slip component is positioned to be in direct contact with the boron source; and By boronizing the matrix material, at least one outer layer is bonded to the bearing surface to form a metallurgical bond between the boron from the boron source and the matrix material, and to maintain the overall temperature of the slip component below the melting point of the matrix material.

10. The slip component according to claim 9, wherein, Maintaining the overall temperature of the slip component below the melting point includes maintaining the overall temperature of the sliding component below the damage temperature at the design strength level of the slip component.

11. The slip component according to claim 9 or 10, wherein, The base material of the slip component includes a nickel superalloy.

12. The slip component according to claim 11, wherein, The nickel superalloy includes UNS N07718.

13. The slip component according to any one of claims 9 to 12, wherein, The treatment of at least the bearing surface also includes increasing at least a portion of the hardness of the outer layer by surface treatment of the outer layer to create compressive stress or release tensile stress.

14. The slip component according to any one of claims 9 to 13, wherein, The slip component includes at least one slip of the slip mechanism of the downhole tool, the slip having a clamping surface that serves as the bearing surface.

15. The slip component according to any one of claims 9 to 14, wherein, The slip components are selected from the slips, cone, and retainer of the slip mechanism of the downhole tool.

16. A method for surface hardening a slip component for a downhole tool, the slip component having a bearing surface and being made of a base material, the base material being a metallic material, the method comprising: At least the bearing surface of the slip component should be positioned to be in direct contact with the boron source; By boronizing the matrix material, at least one outer layer is bonded to the bearing surface; The hardness of the outer layer is increased by performing a surface treatment to create compressive stress or release tensile stress.

17. The method according to claim 16, wherein, The surface treatment of the outer layer includes: Use mechanical processes selected from shot peening, shot blasting, and polishing; or Use non-mechanical processes selected from ultrasonic shot peening and laser shot peening.

18. The method according to any one of claims 16-17, further comprising the step of improving at least a portion of the corrosion resistance of the outer layer through surface treatment.

19. The method according to any one of claims 16-18, further comprising the step of maintaining the overall temperature of the slip component below the melting point of the base material.

20. The method according to any one of claims 16-19, wherein, Maintaining the overall temperature of the slip component below the melting point includes maintaining the overall temperature of the slip component below the temperature at which the design strength level of the slip component would be compromised.

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