A high-strength wear-resistant belt of titanium alloy drill pipe joint and preparation method thereof

Abstract

The invention discloses a high-strength wear-resistant belt of a titanium alloy drill pipe joint and a preparation method thereof, and belongs to the technical field of oil well pipe manufacturing in the petroleum and natural gas industry. The preparation method first performs a surface degreasing and cleaning treatment on the titanium alloy drill pipe joint substrate to be processed, and then performs a grinding treatment to obtain a pretreated titanium alloy drill pipe joint substrate; first grinds the Co‑Cr‑W‑C alloy powder, and then dries it to obtain a dry Co‑Cr‑W‑C alloy powder; adopts an ultra-high-speed laser cladding process to clad the dry Co‑Cr‑W‑C alloy powder on the surface of the pretreated titanium alloy drill pipe joint substrate to obtain a high-strength wear-resistant belt of a titanium alloy drill pipe joint. The high-strength wear-resistant belt of a titanium alloy drill pipe joint prepared by the present invention belongs to a high-strength wear-resistant belt for titanium alloy drill pipes for deep wells and ultra-deep oil wells, which solves the problems of the difficulty of traditional surfacing technology and the poor surface bonding, low hardness, poor wear resistance, and easy generation of cracks and pore defects of the titanium alloy drill pipe wear-resistant belt.

Description

Technical Field

[0001] The invention belongs to the technical field of oil well pipe manufacturing in the petroleum and natural gas industry, and relates to a high-strength wear-resistant belt of a titanium alloy drill pipe joint and a preparation method thereof. Background Art

[0002] In recent years, with the development of the petroleum industry, more and more harsh environment oil and gas wells are faced, and the requirements for materials are getting higher and higher. Titanium alloy drill pipes have excellent properties such as high specific strength, high temperature resistance, and corrosion resistance. They have good application prospects in complex working conditions such as deep wells, large displacement wells, sulfur-containing wells, short radius wells, and high temperature and high pressure wells. However, the wear resistance of titanium alloy is lower than that of steel, and the drill pipe is in a composite load environment of tension, compression and torsion for a long time, which will cause friction with the well wall, affecting the service life of the titanium alloy drill pipe and increasing the cost. Therefore, it is necessary to improve the wear resistance of titanium alloy drill pipe. The traditional steel drill pipe wear-resistant belt is prepared by surfacing. The melting point of titanium alloy material is high. The traditional surfacing method has high requirements for equipment and it is difficult to achieve metallurgical bonding with the wear-resistant belt material. Laser cladding technology belongs to local heating, which has little effect on the performance of the substrate; it is metallurgically bonded with the substrate, has a low dilution rate, and has strong bonding. It can generate a dense and thick coating. It is a very promising method to improve the surface hardness and wear resistance of titanium alloy. When laser cladding wear-resistant coating on titanium alloy surface, the selection of powder material has a great influence on the performance of coating. First, when the thermal physical parameters (such as thermal expansion coefficient, thermal conductivity, elastic modulus, etc.) of powder and titanium alloy substrate are very different, cracks and pores are very easy to occur; secondly, when the bonding between coating and substrate is not high, large pieces of coating may fall off during use; finally, the metallurgical bonding between powder material and substrate forms the phase that increases the microhardness of coating or reduces friction coefficient, reduces wear rate, and improves wear resistance. Therefore, exploring the cladding method and material design of wear-resistant belt of titanium alloy drill pipe has practical significance for the development of petroleum industry. Summary of the invention

[0003] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a high-strength wear-resistant belt of a titanium alloy drill pipe joint and a preparation method thereof, which solves the problems of the difficulty of traditional surfacing technology and the poor surface bonding, low hardness, poor wear resistance, and easy generation of cracks and pore defects of the titanium alloy drill pipe wear-resistant belt.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] The invention discloses a method for preparing a high-strength wear-resistant belt of a titanium alloy drill rod joint. The method comprises the following steps: firstly performing a surface degreasing and cleaning treatment on a titanium alloy drill rod joint substrate to be treated, and then performing a grinding treatment to obtain a pretreated titanium alloy drill rod joint substrate; firstly performing a grinding treatment on a Co-Cr-WC alloy powder, and then performing a drying treatment to obtain a dry Co-Cr-WC alloy powder; and adopting an ultra-high-speed laser cladding process to clad the dry Co-Cr-WC alloy powder on the surface of the pretreated titanium alloy drill rod joint substrate to obtain the high-strength wear-resistant belt of the titanium alloy drill rod joint.

[0006] Preferably, the pretreated titanium alloy drill rod joint matrix is ​​processed to a roughness Ra≤20 μm after grinding.

[0007] Preferably, the Co—Cr—WC alloy powder is ground by ball milling for 5 to 7 hours.

[0008] Preferably, the grinding process is followed by drying, and the drying time is 1.0 to 2.0 hours.

[0009] Preferably, the ultra-high-speed laser cladding process parameters are: laser power 5500-6000W, spot diameter 1.5-2.5mm, scanning line speed 40-55m / min, overlap rate 70-80%, powder feeding rate 20-30g / min; the protective gas during the ultra-high-speed laser cladding process is nitrogen, and the flow rate is 20-25L / min.

[0010] Preferably, the thickness of a single layer of the dried Co—Cr—WC alloy powder cladding on the surface of the pretreated titanium alloy drill rod joint substrate is 0.5 to 1.2 mm.

[0011] Preferably, the mass fractions of the elements in the Co-Cr-WC alloy powder are: 30% to 32% Cr, 10% to 12% W, 2.0% to 2.5% C, and the rest is Co.

[0012] Preferably, the titanium alloy matrix is ​​a Ti-Al-V-Zr-Mo system titanium alloy.

[0013] Preferably, the Co—Cr—WC alloy powder is prepared by vacuum argon atomization, with a particle size range of 25 to 80 μm, a D50 of 25 to 40 μm, and a fluidity of ≤25 s / 50 g.

[0014] The invention discloses a high-strength wear-resistant belt of a titanium alloy drill pipe joint prepared by the preparation method.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The invention provides a method for preparing a high-strength wear-resistant belt of a titanium alloy drill pipe joint. The invention adopts ultra-high-speed laser cladding technology as a preparation means and composite Co-Cr-WC alloy powder as a cladding coating, wherein a Co-Cr-WC alloy powder particle cladding layer is prepared on the surface of the titanium alloy drill pipe joint by adopting the ultra-high-speed laser cladding technology to enhance the wear resistance of the titanium alloy drill pipe joint. The ultra-high-speed laser cladding technology used has the following advantages: uniform laser energy density, small heat input, fast heating, small heat-affected zone, substrate melting depth below 100 μm, and small dilution effect of the parent material on the coating; strong bonding, small residual stress, and more effective suppression of cracks and pores compared with surfacing or conventional laser cladding processes; the thickness of the cladding layer is controllable within the range of 50 to 500 μm and can be adjusted according to specific needs; the cladding efficiency is high, which is 5 to 10 times that of traditional laser cladding.

[0017] The Co-Cr-WC alloy powder used in the present invention is uniformly mixed in a ball mill, and then Cr and C are reacted under the action of laser to generate Cr. 7 C 3 High-hardness carbides improve the wear resistance of the cladding layer; in addition, Cr atoms are dissolved in Co, which improves the strength, high-temperature oxidation resistance and corrosion resistance of the matrix; W atoms are larger than cobalt atoms, and after being dissolved in cobalt, they become barriers to dislocation flow, which can improve the strength of the matrix. When the W content is greater than 10%, part of the W will precipitate in the form of high-hardness carbides during alloy solidification to form (Cr, W, Co) 7 C 3 or (Cr, W, Co) 6 C, increase the high temperature strength of the alloy and improve the wear resistance of the matrix.

[0018] The invention discloses a high-strength wear-resistant belt of a titanium alloy drill pipe joint prepared by the preparation method. The high-strength wear-resistant belt of a titanium alloy drill pipe joint is a high-strength wear-resistant belt for titanium alloy drill pipes of deep wells and ultra-deep oil wells. The particle-reinforced titanium-based wear-resistant belt material layer is prepared on the surface of a titanium alloy substrate by adopting the ultra-high-speed laser cladding method, so as to achieve a dense metallurgical bonding between the titanium alloy substrate and the wear-resistant coating, thereby improving the wear resistance and service life of the titanium alloy drill pipe joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A cross-sectional view of a real joint of a high-strength wear-resistant belt of a titanium alloy drill pipe joint made by the present invention;

[0020] Figure 2 This is a cross-sectional view of the titanium alloy drill pipe joint when the high-strength wear-resistant belt of the titanium alloy drill pipe joint produced by the present invention is subjected to a flattening test. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] The invention discloses a high-strength wear-resistant belt of a titanium alloy drill pipe joint, which realizes a dense metallurgical combination of a titanium alloy substrate and a wear-resistant coating. The preparation method of the high-strength wear-resistant belt of a titanium alloy drill pipe joint comprises the following steps:

[0024] (1) preparing a titanium alloy drill pipe joint substrate, removing oil and cleaning the surface, and grinding it to a roughness Ra≤20 μm to obtain a pretreated titanium alloy drill pipe joint substrate;

[0025] (2) placing the Co-Cr-WC alloy powder in a vacuum ball mill for 5 to 7 hours, and drying for 1.0 to 2.0 hours to obtain a dry Co-Cr-WC alloy powder;

[0026] (3) The dried Co-Cr-WC alloy powder was clad on the surface of the pretreated titanium alloy drill pipe joint substrate by ultra-high-speed laser cladding process, with a single-layer cladding thickness of 0.5-1.2 mm and a total cladding of 2 layers; the ultra-high-speed laser cladding process parameters were: laser power 5500-6000 W, spot diameter 1.5-2.5 mm, scanning line speed 40-55 m / min, overlap rate 70%-80%, and powder feeding rate 20-30 g / min. In this way, a high-strength wear-resistant belt of the titanium alloy drill pipe joint was obtained.

[0027] (4) In a specific application, the obtained high-strength wear-resistant belt of the titanium alloy drill pipe joint is processed to the required size by a grinding machine and applied to specific accessory requirements.

[0028] In the step (1), the titanium alloy matrix is ​​a Ti-Al-V-Zr-Mo system titanium alloy.

[0029] In the step (2), the Co-Cr-WC alloy powder is prepared by vacuum argon atomization, with a particle size range of 25 to 80 μm, a D50 of 25 to 40 μm, and a fluidity of ≤25 s / 50 g.

[0030] The mass fractions of the elements in the Co-Cr-WC alloy powder in step (2) are: 30% to 32% Cr, 10% to 12% W, 2.0% to 2.5% C, and the rest is Co.

[0031] In the step (3), the protective gas in the ultra-high-speed laser cladding process is nitrogen with a flow rate of 20 to 25 L / min.

[0032] The present invention is further described in detail below in conjunction with specific embodiments:

[0033] Embodiment 1:

[0034] An ultra-deep oil well titanium alloy drill pipe wear-resistant belt and a preparation method thereof, specifically comprising the following steps:

[0035] (1) A Ti-Al-V-Zr-Mo titanium alloy drill pipe joint substrate is prepared, the surface is degreased and cleaned, and a grinding process is performed to obtain a surface roughness Ra≈10 μm, thereby obtaining a pretreated titanium alloy drill pipe joint substrate.

[0036] (2) The mass fractions of the elements in the Co-Cr-WC alloy powder are: 30% Cr, 10% W, 2.0% C, and the rest is Co.

[0037] (3) Co-Cr-WC alloy powder was prepared by vacuum argon atomization powder making method, with a particle size range of 25 to 80 μm, D50 of 25 to 40 μm, and fluidity ≤ 25 s / 50 g. The Co-Cr-WC alloy powder was placed in a vacuum ball mill for 5 hours and dried for 2.0 hours to obtain dry Co-Cr-WC alloy powder.

[0038] (4) The ultra-high-speed laser cladding process was used to clad the dry Co-Cr-WC alloy powder on the surface of the Co-Cr-WC alloy powder titanium alloy drill pipe joint substrate. The single-layer cladding thickness was 0.8 mm, the total cladding was 2 layers, the total cladding thickness was 1.6 mm, and the cladding length was 20 mm. The ultra-high-speed laser cladding process parameters were: laser power 5500 W, spot diameter 1.5 mm, scanning line speed 40 m / min, overlap rate 70%, and powder feeding rate 20 g / min. The process protective gas was nitrogen with a flow rate of 20 L / min. In this way, a high-strength wear-resistant belt of a titanium alloy drill pipe joint was obtained.

[0039] (5) The high-strength wear-resistant belt of the titanium alloy drill pipe joint is grinded to a thickness of 1.2 mm.

[0040] The surface of the wear-resistant belt prepared as above was subjected to fluorescent penetrant nondestructive testing according to JB / T 4730.5-2005 standard, and no crack defects were found; the bonding strength test was carried out according to SY / T 6948-2013 standard, and the wear-resistant belt did not peel off, and the wear-resistant belt did not separate from the parent material.

[0041] Embodiment 2:

[0042] An ultra-deep oil well titanium alloy drill pipe wear-resistant belt and a preparation method thereof, specifically comprising the following steps:

[0043] A Ti-Al-V-Zr-Mo titanium alloy drill pipe joint substrate is prepared, the surface is degreased and cleaned, and a grinding process is performed to obtain a surface roughness Ra≈10 μm, thereby obtaining a pretreated titanium alloy drill pipe joint substrate.

[0044] (2) The mass fractions of the elements in the Co-Cr-WC alloy powder are: 31% Cr, 11% W, 2.3% C, and the rest is Co.

[0045] (3) Co-Cr-WC alloy powder was prepared by vacuum argon atomization powder making method, with a particle size range of 25 to 80 μm, D50 of 25 to 40 μm, and fluidity ≤ 25 s / 50 g. The dried Co-Cr-WC alloy powder was placed in a vacuum ball mill for 5 hours and dried for 2.0 hours to obtain a dry Co-Cr-WC alloy powder.

[0046] (4) The dry Co-Cr-WC alloy powder was clad on the surface of the Co-Cr-WC alloy powder titanium alloy drill pipe joint substrate by ultra-high-speed laser cladding process, with a single layer cladding thickness of 0.8 mm, a total cladding of 2 layers, a total cladding thickness of 1.6 mm, and a cladding length of 20 mm. In this way, a high-strength wear-resistant belt of the titanium alloy drill pipe joint was obtained.

[0047] The ultra-high-speed laser cladding process parameters are: laser power 5600W, spot diameter 2.0mm, scanning line speed 45m / min, overlap rate 65%, powder feeding rate 20g / min. The process protection gas is nitrogen with a flow rate of 22L / min.

[0048] (5) The high-strength wear-resistant belt of the titanium alloy drill pipe joint is grinded to a thickness of 1.2 mm.

[0049] The surface of the wear-resistant belt prepared as above was subjected to fluorescent penetrant nondestructive testing according to JB / T 4730.5-2005 standard, and no crack defects were found; the bonding strength test was carried out according to SY / T 6948-2013 standard, and the wear-resistant belt did not peel off, and the wear-resistant belt did not separate from the parent material.

[0050] Embodiment 3:

[0051] An ultra-deep oil well titanium alloy drill pipe wear-resistant belt and a preparation method thereof, specifically comprising the following steps:

[0052] (1) A Ti-Al-V-Zr-Mo titanium alloy drill pipe joint substrate is prepared, the surface is degreased and cleaned, and a grinding process is performed to obtain a surface roughness Ra≈5 μm, thereby obtaining a pretreated titanium alloy drill pipe joint substrate.

[0053] (2) The mass fractions of the elements in the Co-Cr-WC alloy powder are: 32% Cr, 12% W, 2.5% C, and the rest is Co.

[0054] (3) Co-Cr-WC alloy powder was prepared by vacuum argon atomization, with a particle size range of 25-80 μm, D50 of 25-40 μm, and fluidity ≤ 25 s / 50 g. The Co-Cr-WC alloy powder was ball milled in a vacuum ball mill for 7 hours and dried for 1.0 hour to obtain dry Co-Cr-WC alloy powder.

[0055] (4) The ultra-high-speed laser cladding process was used to clad the dry Co-Cr-WC alloy powder on the surface of the Co-Cr-WC alloy powder titanium alloy drill pipe joint substrate. The single-layer cladding thickness was 0.8 mm, the total cladding was 2 layers, the total cladding thickness was 1.6 mm, and the cladding length was 20 mm. The ultra-high-speed laser cladding process parameters were: laser power 5700 W, spot diameter 2.5 mm, scanning line speed 55 m / min, overlap rate 75%, and powder feeding rate 25 g / min. The process protective gas was nitrogen with a flow rate of 25 L / min. In this way, a high-strength wear-resistant belt of a titanium alloy drill pipe joint was obtained.

[0056] (5) The high-strength wear-resistant belt of the titanium alloy drill pipe joint is grinded to a thickness of 1.2 mm.

[0057] The surface of the wear-resistant belt prepared as above was subjected to fluorescent penetrant nondestructive testing according to JB / T 4730.5-2005 standard, and no crack defects were found; the bonding strength test was carried out according to SY / T 6948-2013 standard, and the wear-resistant belt did not peel off, and the wear-resistant belt did not separate from the parent material.

[0058] Embodiment 4:

[0059] An ultra-deep oil well titanium alloy drill pipe wear-resistant belt and a preparation method thereof, specifically comprising the following steps:

[0060] (1) A Ti-Al-V-Zr-Mo titanium alloy drill pipe joint substrate is prepared, the surface is degreased and cleaned, and a grinding process is performed to obtain a surface roughness Ra≈2 μm, thereby obtaining a pretreated titanium alloy drill pipe joint substrate.

[0061] (2) The mass fractions of the elements in the Co-Cr-WC alloy powder are: 32% Cr, 12% W, 2.5% C, and the rest is Co.

[0062] (3) Co-Cr-WC alloy powder was prepared by vacuum argon atomization, with a particle size range of 25-80 μm, D50 of 25-40 μm, and fluidity ≤25 s / 50 g. The Co-Cr-WC alloy powder was placed in a vacuum ball mill for 5.5 hours and dried for 1.8 hours to obtain a dry Co-Cr-WC alloy powder.

[0063] (4) The dry Co-Cr-WC alloy powder was clad on the surface of the Co-Cr-WC alloy powder titanium alloy drill pipe joint substrate by ultra-high-speed laser cladding process. The single-layer cladding thickness was 0.7 mm, the total cladding was 2 layers, the total cladding thickness was 1.4 mm, and the cladding length was 20 mm. The ultra-high-speed laser cladding process parameters were: laser power 5800 W, spot diameter 2.0 mm, scanning line speed 50 m / min, overlap rate 80%, and powder feeding rate 30 g / min. The process protective gas was nitrogen with a flow rate of 21 L / min. In this way, a high-strength wear-resistant belt of a titanium alloy drill pipe joint was obtained.

[0064] (5) The high-strength wear-resistant belt of the titanium alloy drill pipe joint is grinded to a thickness of 1.2 mm.

[0065] The surface of the wear-resistant belt prepared as above was subjected to fluorescent penetrant nondestructive testing according to JB / T 4730.5-2005 standard, and no crack defects were found; the bonding strength test was carried out according to SY / T 6948-2013 standard, and the wear-resistant belt did not peel off, and the wear-resistant belt did not separate from the parent material.

[0066] Embodiment 5:

[0067] An ultra-deep oil well titanium alloy drill pipe wear-resistant belt and a preparation method thereof, specifically comprising the following steps:

[0068] (1) A Ti-Al-V-Zr-Mo titanium alloy drill pipe joint substrate is prepared, the surface is degreased and cleaned, and a grinding process is performed to obtain a surface roughness Ra≈15 μm, thereby obtaining a pretreated titanium alloy drill pipe joint substrate.

[0069] (2) The mass fractions of the elements in the Co-Cr-WC alloy powder are: 31% Cr, 11% W, 2.2% C, and the rest is Co.

[0070] (3) Co-Cr-WC alloy powder was prepared by vacuum argon atomization, with a particle size range of 25-80 μm, D50 of 25-40 μm, and fluidity ≤ 25 s / 50 g. The Co-Cr-WC alloy powder was ball milled in a vacuum ball mill for 6 hours and dried for 1.5 hours to obtain dry Co-Cr-WC alloy powder.

[0071] (4) The ultra-high-speed laser cladding process was used to clad the dry Co-Cr-WC alloy powder on the surface of the Co-Cr-WC alloy powder titanium alloy drill pipe joint substrate. The single-layer cladding thickness was 1.2 mm, the total cladding thickness was 2.4 mm, and the cladding length was 20 mm. The ultra-high-speed laser cladding process parameters were: laser power 5900 W, spot diameter 1.5 mm, scanning line speed 40 m / min, overlap rate 75%, and powder feeding rate 28 g / min. The process protective gas was nitrogen with a flow rate of 24 L / min. In this way, a high-strength wear-resistant belt of a titanium alloy drill pipe joint was obtained.

[0072] (5) The high-strength wear-resistant belt of the titanium alloy drill pipe joint is grinded to a thickness of 1.2 mm.

[0073] The surface of the wear-resistant belt prepared as above was subjected to fluorescent penetrant nondestructive testing according to JB / T 4730.5-2005 standard, and no crack defects were found; the bonding strength test was carried out according to SY / T 6948-2013 standard, and the wear-resistant belt did not peel off, and the wear-resistant belt did not separate from the parent material.

[0074] Embodiment 6:

[0075] An ultra-deep oil well titanium alloy drill pipe wear-resistant belt and a preparation method thereof, specifically comprising the following steps:

[0076] (1) A Ti-Al-V-Zr-Mo titanium alloy drill pipe joint substrate is prepared, the surface is degreased and cleaned, and a grinding process is performed to obtain a surface roughness Ra≈20 μm, thereby obtaining a pretreated titanium alloy drill pipe joint substrate.

[0077] (2) The mass fractions of the elements in the Co-Cr-WC alloy powder are: 30% Cr, 10% W, 2.4% C, and the rest is Co.

[0078] (3) Co-Cr-WC alloy powder was prepared by vacuum argon atomization, with a particle size range of 25-80 μm, D50 of 25-40 μm, and fluidity ≤ 25 s / 50 g. The Co-Cr-WC alloy powder was ball milled in a vacuum ball mill for 6.5 hours and dried for 1.2 hours to obtain dry Co-Cr-WC alloy powder.

[0079] (4) The dry Co-Cr-WC alloy powder was clad on the surface of the Co-Cr-WC alloy powder titanium alloy drill pipe joint substrate by ultra-high-speed laser cladding process, with a single-layer cladding thickness of 1.0 mm, a total cladding thickness of 2.0 mm, and a cladding length of 20 mm. The ultra-high-speed laser cladding process parameters are: laser power 6000 W, spot diameter 2.5 mm, scanning line speed 55 m / min, overlap rate 70%, and powder feeding rate 21 g / min. The process protective gas is nitrogen with a flow rate of 23 L / min. In this way, a high-strength wear-resistant belt of a titanium alloy drill pipe joint is obtained.

[0080] (5) The high-strength wear-resistant belt of the titanium alloy drill pipe joint is grinded to a thickness of 1.2 mm.

[0081] The surface of the wear-resistant belt prepared as above was subjected to fluorescent penetrant nondestructive testing according to JB / T 4730.5-2005 standard, and no crack defects were found; the bonding strength test was carried out according to SY / T 6948-2013 standard, and the wear-resistant belt did not peel off, and the wear-resistant belt did not separate from the parent material.

[0082] The hardness test of the wear-resistant belts prepared in the above-mentioned Examples 1 to 3 was carried out respectively by using a microhardness tester. The test standard was in accordance with GB / T 2654-2008. Each wear-resistant belt coating was tested at 15 points and the average hardness value was taken. At the same time, the same hardness test was carried out for comparison with the conventional alloy steel surfacing wear-resistant belt. The test results are shown in Table 1.

[0083] The wear-resistant belts prepared in the above-mentioned embodiments 1 to 3 were subjected to the test ring-test block sliding wear test respectively. The test standard was in accordance with GB / T 12444-2006. The upper test block was made of hard alloy YG8 with a hardness of about HV1400, and the lower test ring was a wear test ring with a wear-resistant coating. The test load was 200N, the rotation speed was 200r / min, and the time was 60min. The wear resistance of the material was calibrated by the weight loss of wear. Three groups were tested for each embodiment and the average value was taken. At the same time, the same friction and wear test was carried out in comparison with the traditional alloy steel surfacing wear-resistant belt. The test results are shown in Table 1.

[0084] Table 1 Hardness and weight loss of wear-resistant belt

[0085] Case Hardness (HV) Weight loss (mg) Example 1 735 58 Example 2 756 50 Example 3 772 45 Steel drill pipe joint surfacing wear-resistant belt 668 103

[0086] It can be seen from the above table that the hardness and friction loss weight of the Co-Cr-WC alloy powder reinforced titanium alloy drill pipe joint wear-resistant belt prepared by ultra-high-speed laser cladding method are higher than those of the steel drill pipe joint surfacing wear-resistant belt, showing better wear resistance. At the same time, with the increase of various alloying elements of the Co-Cr-WC alloy, the hardness of the wear-resistant belt gradually increases and the wear resistance improves.

[0087] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0088] See also Figure 1 and Figure 2 It can be seen that a wear-resistant belt with a uniform thickness of about 2 mm is formed on the surface of the drill pipe. When its hardness is tested by a flattening test, the wear-resistant belt does not warp or fall off. The results show that the prepared wear-resistant belt is uniform and dense, and has good bonding with the substrate.

[0089] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a high-strength wear-resistant belt of a titanium alloy drill pipe joint, characterized in that: The titanium alloy drill rod joint substrate to be treated is first subjected to a surface degreasing and cleaning treatment, and then subjected to a grinding treatment to obtain a pretreated titanium alloy drill rod joint substrate; The Co-Cr-WC alloy powder is firstly ground and then dried to obtain a dry Co-Cr-WC alloy powder; The ultra-high-speed laser cladding process is used to clad the dry Co-Cr-WC alloy powder on the surface of the pre-treated titanium alloy drill pipe joint substrate to obtain a high-strength wear-resistant belt of the titanium alloy drill pipe joint. The mass fractions of the elements in the Co-Cr-WC alloy powder are: 30%~32% Cr, 10%~12% W, 2.0%~2.5% C, and the rest is Co; The titanium alloy matrix is ​​a Ti-Al-V-Zr-Mo system titanium alloy; The process parameters of ultra-high-speed laser cladding are: laser power 5500-6000W, spot diameter 1.5-2.5mm, scanning line speed 40-55m / min, overlap rate 70-80%, powder feeding rate 20-30g / min; The protective gas during the ultra-high-speed laser cladding process is nitrogen, with a flow rate of 20-25L / min; The single-layer cladding thickness of the dry Co-Cr-WC alloy powder on the pretreated titanium alloy drill pipe joint substrate is 0.5 to 1.2 mm; The high-strength wear-resistant belt of the titanium alloy drill pipe joint contains high-hardness carbides (Cr, W, Co)7C3 or (Cr, W, Co)6C; After grinding, the obtained pretreated titanium alloy drill pipe joint substrate is processed to a roughness Ra≤20μm; The Co-Cr-WC alloy powder is ground by ball milling for 5 to 7 hours.

2. The preparation method according to claim 1, characterized in that: After grinding, the powder is dried for 1.0 to 2.0 hours.

3. The preparation method according to claim 1, characterized in that: The Co-Cr-WC alloy powder is prepared by vacuum argon atomization, with a particle size range of 25 to 80 μm, a D50 of 25 to 40 μm, and a fluidity of ≤25 s / 50 g.

4. A high-strength wear-resistant belt for a titanium alloy drill pipe joint prepared by the preparation method according to any one of claims 1 to 3.

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