Non-magnetic steel surface wear-resistant belt, laser cladding preparation method and application

Abstract

The invention provides a non-magnetic steel surface wear-resistant belt and a laser cladding preparation method and application, and the laser cladding preparation method comprises the following steps: conveying transition bottom layer nickel-based non-magnetic alloy powder to a pretreated non-magnetic steel substrate, and carrying out laser cladding to obtain a transition bottom layer; the first nickel-based mixed alloy powder is conveyed to the transition bottom layer cladding layer, laser cladding is conducted, and a middle wear-resisting layer is formed outside the transition bottom layer; second nickel-based mixed alloy powder is conveyed to the middle wear-resistant layer cladding layer, laser cladding is carried out, and a surface wear-resistant layer is formed outside the middle wear-resistant layer; and after cladding of the surface wear-resistant layer is completed, the workpiece is slowly cooled to the room temperature in the heat preservation cotton, the surface wear-resistant layer is polished, and the non-magnetic steel surface wear-resistant belt is obtained. According to the method, the bonding strength, functionality and stability are considered, and the strict requirement of the non-magnetic field scene for the wear-resistant coating is met.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology for oil drilling equipment, specifically to a non-magnetic steel surface wear-resistant strip and its laser cladding preparation method and application. Background Technology

[0002] Drill collars are key equipment in oil drilling. The wear resistance of their surface directly affects the service life of the drill string and drilling efficiency. The non-magnetic steel components in the drill collar must be non-magnetic to ensure the normal operation of the downhole measurement instrument. The traditional laser cladding method involves laying WC ceramic phase in the target area of ​​the metal matrix. However, the thermophysical properties of WC ceramic phase and metal matrix are very different. When cladding with high WC content, defects such as cracks and pores are easy to occur. In addition, WC particles are heavy and tend to sink in the molten pool, resulting in uneven distribution of the reinforcing phase, poor surface wear resistance, and the magnetic properties generated after WC ceramic phase cladding, which interferes with the signal transmission of the measurement while drilling system. Summary of the Invention

[0003] To address the issues of magnetic interference, high crack sensitivity, and uneven distribution of reinforcing phases in composite coatings prepared by traditional laser cladding methods that involve depositing WC ceramic phases onto target areas of a metal substrate, this invention provides a non-magnetic steel surface wear-resistant strip, a laser cladding preparation method, and its application.

[0004] To achieve the above objectives, the present invention provides the following technical solution: This invention proposes a laser cladding method for preparing wear-resistant strips on non-magnetic steel surfaces, characterized by comprising the following steps: S1. The transition bottom layer nickel-based non-magnetic alloy powder is transported onto the pretreated non-magnetic steel substrate and laser cladding is performed to obtain the transition bottom layer; S2. The first nickel-based mixed alloy powder is fed onto the transition bottom cladding layer and laser cladding is performed to form an intermediate wear-resistant layer on the outside of the transition bottom layer. S3. The second nickel-based mixed alloy powder is fed onto the intermediate wear-resistant cladding layer and laser cladding is performed to form a surface wear-resistant layer on the outside of the intermediate wear-resistant layer. S4. After the surface wear-resistant layer is clad, the workpiece is slowly cooled to room temperature in the insulation cotton, and the surface wear-resistant layer is polished to obtain a non-magnetic steel surface wear-resistant strip. Preferably, the transitional bottom layer nickel-based non-magnetic alloy powder is composed of elements with a mass fraction of 0.05%~0.1% carbon, 20.0%~23.0% chromium, 59%~66.0% nickel, 3.0%~4.0% iron, 8.0%~10.0% molybdenum, 3.0%~4.1% niobium, 0.1%~0.5% silicon, 0.1%~0.15% sulfur, 0.1%~0.15% phosphorus, and 0.1%~0.5% manganese, wherein the sum of the mass fractions of the elements chromium, nickel, iron, molybdenum, niobium, carbon, silicon, phosphorus, and manganese is 100%. The particle size of the transition bottom layer nickel-based non-magnetic alloy powder is 200 mesh to 400 mesh.

[0005] Preferably, the first nickel-based mixed alloy powder is obtained by mixing nickel-based alloy powder (64.0%~79.5% by mass), tungsten carbide powder (15.0%~25.0% by mass), titanium carbide powder (5.0%~10.0% by mass), and yttrium oxide powder (0.5%~1.0% by mass), wherein the sum of the mass fractions of the nickel-based alloy powder, the tungsten carbide powder, the titanium carbide powder, and the yttrium oxide powder is 100%. The second nickel-based mixed alloy powder is obtained by mixing nickel-based alloy powder (55.0%~74.5% by mass), tungsten carbide powder (20.0%~30.0% by mass), titanium carbide powder (5.0%~15.0% by mass), and yttrium oxide powder (0.5%~1.0% by mass), wherein the sum of the mass fractions of the nickel-based mixed alloy powder, the tungsten carbide powder, the titanium carbide powder, and the yttrium oxide powder is 100%. The nickel-based alloy powder is composed of 0.03% carbon, 5.00% chromium, 89.97% nickel, 1.00% silicon, 0.50% iron, 0.50% boron, 2.4% molybdenum, and 0.6% niobium by mass fraction.

[0006] Preferably, in step S1, nickel-based non-magnetic alloy powder is clad onto the outer wall of the pretreated non-magnetic steel substrate to form a transition layer with a thickness of 0.5 mm to 1.0 mm under the conditions of laser power of 2500 W to 3500 W, laser scanning speed of 30 mm / s to 50 mm / s, laser spot diameter of 3 mm to 5 mm, and laser overlap rate of 50% to 55%.

[0007] Preferably, in step S2, the first nickel-based mixed alloy powder is clad onto the transition substrate to form an intermediate wear-resistant layer with a thickness of 1.0 mm to 1.5 mm under the conditions of laser power of 2000 W to 2500 W, laser scanning speed of 10 mm / s to 20 mm / s, laser spot diameter of 3 mm to 5 mm, and laser overlap rate of 45% to 50%.

[0008] Preferably, in step S3, the second nickel-based mixed alloy powder is clad onto the intermediate wear-resistant layer to form a surface wear-resistant layer with a thickness of 1.0 mm to 1.5 mm under the conditions of laser power of 1100 W to 2100 W, laser scanning speed of 10 mm / s to 15 mm / s, laser spot diameter of 3 mm to 5 mm, and laser overlap rate of 45% to 50%.

[0009] Preferably, in S1 to S3, powder is fed at a rate of 15 g / min to 45 g / min, and nitrogen gas with a flow rate of 15 to 20 L / min is used as a protective gas during the laser cladding process.

[0010] Preferably, in step S1, the pretreatment of the non-magnetic steel substrate includes: The non-magnetic steel substrate is machined by turning. The machined surface is then degreased and derusted. The surface of the non-magnetic steel substrate is then cleaned with acetone cleaning solution. After cleaning, the workpiece is heated with an oxyacetylene flame at a temperature of 100℃~150℃.

[0011] The present invention also proposes a non-magnetic steel surface wear-resistant strip, which is prepared by the above-mentioned preparation method and includes a transition layer, an intermediate wear-resistant layer and a surface wear-resistant layer sequentially disposed outside the non-magnetic steel substrate.

[0012] The present invention also proposes an application of the above-mentioned non-magnetic steel surface wear-resistant strip, which is applied to oil drill collars.

[0013] Compared with the prior art, the present invention has the following beneficial technical effects: This invention proposes a laser cladding method for preparing wear-resistant strips on non-magnetic steel surfaces. This method uses a mixture of tungsten carbide and titanium carbide powders as the reinforcing phase, combining the high hardness of tungsten carbide with the burn-resistance of titanium carbide. It is then combined with an optimized non-magnetic nickel-based alloy with a precise ratio of chromium, nickel, molybdenum, and niobium, overcoming the core contradiction between the performance limitations of a single reinforcing phase and the requirement for non-magnetic properties. A three-layer gradient is then used: a transitional underlayer, an intermediate layer, and a surface wear-resistant layer. The transitional underlayer is metallurgically bonded to the non-magnetic steel substrate to solidify the non-magnetic base. The intermediate and surface wear-resistant layers gradually stack the reinforcing phase density, resulting in a smooth transition in the interlayer thermal expansion coefficient, thus suppressing crack formation at its source. Customized laser parameters and multi-layer step-by-step cladding address the problems of cracking, reinforcing phase burn-resistance, and uneven distribution in high-ceramic-content cladding layers. Heat preservation, slow cooling, and polishing further optimize the quality, ultimately yielding a wear-resistant strip with excellent non-magnetic properties, extremely low crack rate, and balanced wear resistance. This method takes into account the combination of strength, functionality and stability, and is suitable for the stringent requirements of wear-resistant coatings in non-magnetic scenarios, significantly improving the service life of non-magnetic steel components.

[0014] Furthermore, this method, through optimized nickel-based non-magnetic transition underlayer design and strict control of B and Si element content, and the wear-resistant layer using nickel-based non-magnetic matrix mixed with tungsten carbide and titanium carbide non-magnetic ceramic phase materials, ensures that the cladding layer is entirely non-magnetic, meeting the non-magnetic requirements of drill collars.

[0015] Furthermore, the synergistic effect of the mixed tungsten carbide and titanium carbide powders as reinforcing phases in this method makes the distribution of the reinforcing phase in the wear-resistant layer more reasonable, and the wear resistance is improved by more than 30% compared with a single reinforcing phase. The coating hardness can reach more than HV2800, and the volume ratio of hard reinforcing phase in the cladding layer reaches more than 60%.

[0016] Furthermore, this method effectively alleviates stress concentration caused by mismatch in thermal expansion coefficients and inhibits crack formation through material composition optimization design, wear-resistant layer gradient structure design, and process parameter optimization.

[0017] Furthermore, the optimized laser parameters and molten pool convection control in this method ensure a uniform distribution of WC and TiC reinforcing phases, avoiding the problem of reduced surface reinforcing phase proportion caused by tungsten carbide particle settling.

[0018] Furthermore, in this method, the transition layer forms a good metallurgical bond with the non-magnetic steel matrix, with a bond strength exceeding 300 MPa.

[0019] Furthermore, in this method, a transition layer with a thickness of 0.5 mm to 1.0 mm is formed by cladding nickel-based non-magnetic alloy powder. Under the conditions of laser scanning speed of 30 mm / s to 50 mm / s and laser spot diameter of 3 mm to 5 mm, a micro-melting layer is formed on the outer wall of the non-magnetic steel substrate by the nickel-based alloy powder. The metallurgical bonding interface is formed through element interdiffusion to increase the strength, achieve metallurgical bonding, reduce the risk of peeling, and also reduce the thermal stress caused by thermal expansion differences during cladding cooling. This avoids grain coarsening or thermal deformation caused by excessive heating of the substrate and reduces the risk of cracking at the interface and the bottom layer. The laser overlap rate of 50% to 55% compensates for edge protrusion defects of single-pass cladding, controls the surface roughness of the transition bottom layer and the uniformity deviation of the cladding layer thickness, and thus improves the surface smoothness.

[0020] Furthermore, in this method, the 1.0mm~1.5mm intermediate wear-resistant layer formed by the first nickel-based mixed alloy powder under specified laser cladding process parameters ensures consistency with the non-magnetic properties of the transition layer and the substrate. Through metallurgical bonding, it achieves high-strength compatibility with the transition layer. A 45%~50% overlap rate combined with a 3mm~5mm spot diameter ensures the wear-resistant layer is continuous, dense, and uniform in thickness, without obvious porosity or incomplete fusion defects. The matching of 2000W~2500W laser power and 10mm / s~20mm / s scanning speed promotes the full melting of the alloy powder and the formation of a uniform wear-resistant and reinforced structure, significantly improving surface hardness and wear resistance, effectively resisting friction and wear in operating conditions. Simultaneously, the heat input under these process parameters avoids performance degradation caused by overheating of the transition layer and the substrate, alleviating interlayer thermal stress and reducing the risk of cracking. The 1.0mm~1.5mm thickness design not only guarantees wear-resistant life but also reserves space for subsequent possible functional layers or finishing processes, comprehensively improving the service reliability and applicability of the component.

[0021] Furthermore, in this method, the 1.0mm~1.5mm wear-resistant surface layer formed by cladding the second nickel-based mixed alloy powder under specified process parameters forms a metallurgical bond with the intermediate wear-resistant layer. The 45%~50% overlap rate combined with the 3mm~5mm spot diameter ensures that the layer is continuous, dense, and free of obvious defects. The wide range of laser power (1100W~2100W) and scanning speed (10mm / s~15mm / s) are matched to ensure that the alloy powder is fully melted and that the uniform precipitation of the wear-resistant strengthening phase is promoted by controlling the heat input, which significantly improves the surface hardness and wear resistance, effectively resisting the severe friction and impact wear under complex working conditions. At the same time, reasonable heat input control can avoid overheating and deterioration of the intermediate wear-resistant layer and the transition layer, alleviate interlayer thermal stress, and reduce the risk of cracking and peeling. The 1.0mm~1.5mm thickness further extends the wear-resistant service life and forms a gradient wear-resistant system with the intermediate wear-resistant layer, which together ensures the overall wear resistance reliability of the component and broadens its application scenarios under high wear conditions. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the laser cladding process for preparing a wear-resistant strip on a non-magnetic steel surface, as proposed in this invention. Figure 2 This is a metallographic schematic diagram of a non-magnetic steel surface wear-resistant strip proposed in this invention; Figure 3 This is a hardness test curve of a wear-resistant band on a non-magnetic steel surface proposed in this invention; Figure 4 This is a schematic diagram of the structure of a non-magnetic steel surface wear-resistant strip proposed in this invention. Detailed Implementation

[0023] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0026] This invention proposes a laser cladding method for preparing wear-resistant strips on non-magnetic steel surfaces, such as... Figure 1 As shown, it includes the following steps: S1. The transition bottom layer nickel-based non-magnetic alloy powder is transported onto the pretreated non-magnetic steel substrate and laser cladding is performed to obtain the transition bottom layer; S2. The first nickel-based mixed alloy powder is fed onto the transition bottom cladding layer and laser cladding is performed to form an intermediate wear-resistant layer on the outside of the transition bottom layer. S3. The second nickel-based mixed alloy powder is fed onto the intermediate wear-resistant cladding layer and laser cladding is performed to form a surface wear-resistant layer on the outside of the intermediate wear-resistant layer. S4. After the surface wear-resistant layer is clad, the workpiece is slowly cooled to room temperature in the insulation cotton, and the surface wear-resistant layer is polished to obtain a non-magnetic steel surface wear-resistant strip.

[0027] The transition layer nickel-based non-magnetic alloy powder consists of 0.05%–0.1% carbon, 20.0%–23.0% chromium, 59%–66.0% nickel, 3.0%–4.0% iron, 8.0%–10.0% molybdenum, 3.0%–4.1% niobium, 0.1%–0.5% silicon, 0.1%–0.15% sulfur, 0.1%–0.15% phosphorus, and 0.1% nickel by mass. The elemental composition is 0.5%~0.5% manganese, wherein the sum of the mass fractions of elements chromium, nickel, iron, molybdenum, niobium, carbon, silicon, phosphorus, and manganese is 100%; the particle size of the transition bottom layer nickel-based non-magnetic alloy powder is 200 mesh~400 mesh; the first nickel-based mixed alloy powder consists of 64.0%~79.5% nickel-based alloy powder, 15.0%~25.0% tungsten carbide powder, and 5.0%~10.0% tungsten carbide powder by mass fraction. The first nickel-based mixed alloy powder is obtained by mixing titanium powder with 0.5% to 1.0% yttrium oxide powder, wherein the sum of the mass fractions of nickel-based alloy powder, tungsten carbide powder, titanium carbide powder, and yttrium oxide powder is 100%. The second nickel-based mixed alloy powder consists of 55.0% to 74.5% nickel-based alloy powder, 20.0% to 30.0% tungsten carbide powder, 5.0% to 15.0% titanium carbide powder, and 0.5% to 1.0% yttrium oxide powder by mass fraction. The mixture is prepared by mixing powders, wherein the total mass fraction of nickel-based mixed alloy powder, tungsten carbide powder, titanium carbide powder, and yttrium oxide powder is 100%; the nickel-based alloy powder is composed of 0.03% carbon, 5.00% chromium, 89.97% nickel, 1.00% silicon, 0.50% iron, 0.50% boron, 2.4% molybdenum, and 0.6% niobium by mass fraction; the tungsten carbide powder is WC, and the titanium carbide powder is TiC.

[0028] This invention uses a mixture of WC and TiC powder as the reinforcing phase, leveraging the synergistic advantages of WC's high hardness and TiC's resistance to burn-off. It is combined with an optimized non-magnetic nickel-based alloy system as the matrix, and a precise ratio of elements such as chromium, nickel, molybdenum, and niobium is used to solidify the non-magnetic foundation, thus resolving the core contradiction between the performance limitations of a single reinforcing phase and the requirement for non-magnetic properties. Addressing the issue of cracking caused by thermal stress concentration in traditional single-layer coatings, this invention features a transitional underlayer with a highly compatible composition with the non-magnetic steel matrix, achieving a strong metallurgical bond while simultaneously laying a non-magnetic base. The intermediate and surface wear-resistant layers progressively stack the reinforcing phase density, allowing for a smooth transition in the interlayer thermal expansion coefficient, effectively buffering thermal stress at the structural level and significantly reducing the probability of crack formation. This invention employs customized laser parameter combinations and a multi-layer, step-by-step cladding strategy, matching differentiated melting parameters to the performance requirements of different layers. Combined with the precise delivery of 200-400 mesh fine powder, the reinforcing phase is fully dispersed in the molten pool without agglomeration, avoiding burn-off and ensuring uniform and stable wear resistance. Finally, a heat-holding and slow-cooling process further optimizes the coating quality. This preparation method is the first to apply WC+TiC hybrid reinforced phase laser cladding technology system to the surface of non-magnetic steel in oil drill collars.

[0029] Furthermore, in this embodiment, the specific preparation steps include the following steps: S1. The non-magnetic steel substrate is machined by turning. The surface after turning is degreased and derusted. Then, the surface of the non-magnetic steel substrate is cleaned with acetone cleaning solution. After cleaning, the workpiece is heated with an oxyacetylene flame at a temperature of 100℃~150℃.

[0030] A transitional nickel-based non-magnetic alloy powder is selected, consisting of elements with a mass fraction of 0.05%~0.1% carbon, 20.0%~23.0% chromium, 59%~66.0% nickel, 3.0%~4.0% iron, 8.0%~10.0% molybdenum, 3.0%~4.1% niobium, 0.1%~0.5% silicon, 0.1%~0.15% sulfur, 0.1%~0.15% phosphorus, and 0.1%~0.5% manganese, and the particle size of the transitional nickel-based non-magnetic alloy powder is 200 mesh~400 mesh.

[0031] Nickel-based non-magnetic alloy powder is fed onto a pretreated non-magnetic steel substrate at a rate of 24-45 g / min. Laser cladding is performed with a laser power of 2500W~3500W, a laser scanning speed of 30mm / s~50mm / s, a laser spot diameter of 3mm~5mm, and a laser overlap rate of 50%~55%, and nitrogen gas is introduced at a flow rate of 15L / min to obtain a transition underlayer with a thickness of 0.5mm~1.0mm. S2. A first nickel-based mixed alloy powder is obtained by mixing nickel-based alloy powder (64.0%~79.5% by mass), tungsten carbide powder (15.0%~25.0% by mass), titanium carbide powder (5.0%~10.0% by mass), and yttrium oxide powder (0.5%~1.0% by mass). The total mass fraction of nickel-based alloy powder, tungsten carbide powder, titanium carbide powder, and yttrium oxide powder is 100%. The particle size of yttrium oxide powder is 50nm~100nm, and the particle size of titanium carbide powder is 100mesh~270mesh.

[0032] The first nickel-based mixed alloy powder is fed onto the cladding transition layer at a rate of 15~30g / min. Laser cladding is performed with a laser power of 2000W~2500W, a laser scanning speed of 10mm / s~20mm / s, a laser spot diameter of 3mm~5mm, and a laser overlap rate of 45%~50%, and nitrogen gas with a flow rate of 15L / min is introduced. This forms an intermediate wear-resistant layer with a thickness of 1.0mm~1.5mm on the outside of the transition layer. S3. Mixing nickel-based alloy powder (55.0%~74.5% by mass), tungsten carbide powder (20.0%~30.0% by mass), titanium carbide powder (5.0%~15.0% by mass), and yttrium oxide powder (0.5%~1.0% by mass) to obtain a second nickel-based mixed alloy powder, wherein the sum of the mass fractions of nickel-based alloy powder, tungsten carbide powder, titanium carbide powder, and yttrium oxide powder is 100%, and the particle size of yttrium oxide powder is 50nm~100nm.

[0033] The second nickel-based mixed alloy powder is fed onto the intermediate wear-resistant layer after cladding at a rate of 15~25g / min. Laser cladding is performed with a laser power of 1100W~2100W, a laser scanning speed of 10mm / s~15mm / s, a laser spot diameter of 3mm~5mm, and a laser overlap rate of 45%~50%, and nitrogen gas with a flow rate of 15L / min is introduced. A surface wear-resistant layer with a thickness of 1.0mm~1.5mm is formed on the outside of the intermediate wear-resistant layer. S4. After the surface wear-resistant layer is clad, it is slowly cooled to room temperature in the insulation cotton, and the surface wear-resistant layer is polished to obtain a non-magnetic steel surface wear-resistant strip. In this embodiment, the nickel-based alloy powder is composed of 0.03% carbon, 5.00% chromium, 89.97% nickel, 1.00% silicon, 0.50% iron, 0.50% boron, 2.4% molybdenum, and 0.6% niobium by mass.

[0034] The preparation method described above will be further explained and illustrated through specific examples below; In the following embodiments, the non-magnetic steel substrate is P550 non-magnetic steel with a specification of Φ120×150mm.

[0035] Example 1 S1. The non-magnetic steel substrate is machined by turning. The surface after turning is degreased and derusted. Then, the surface of the non-magnetic steel substrate is cleaned with acetone cleaning solution. After cleaning, the workpiece is heated with an oxyacetylene flame to a temperature of 100℃.

[0036] A transitional bottom layer nickel-based non-magnetic alloy powder was selected, consisting of 0.05% carbon, 20.0% chromium, 65.0% nickel, 3.0% iron, 8.0% molybdenum, 3.0% niobium, 0.5% silicon, 0.15% sulfur, 0.1% phosphorus, and 0.2% manganese by mass, with a particle size of 200-400 mesh.

[0037] The above-mentioned nickel-based non-magnetic alloy powder was fed onto the pretreated non-magnetic steel substrate at a rate of 24 g / min using nitrogen gas. Under the parameters of laser power of 2500 W, laser scanning speed of 50 mm / s, laser spot diameter of 3 mm, and laser overlap rate of 50%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding to obtain a transition underlayer with a thickness of 0.5 mm.

[0038] S2. Mix 79.5% nickel-based alloy powder, 15.0% tungsten carbide powder, 5.0% titanium carbide powder and 0.5% yttrium oxide powder by mass to obtain the first nickel-based mixed alloy powder. The particle size of the yttrium oxide powder is 50 nm and the particle size of the titanium carbide powder is 100-270 mesh.

[0039] The first nickel-based mixed alloy powder was fed onto the transition layer after cladding at a rate of 15 g / min using nitrogen gas. Under the parameters of laser power of 2000 W, laser scanning speed of 20 mm / s, laser spot diameter of 3 mm, and laser overlap rate of 45%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding, forming an intermediate wear-resistant layer with a thickness of 1.0 mm on the outside of the transition layer.

[0040] S3. Mix 55.0% nickel-based alloy powder, 30.0% tungsten carbide powder, 14.5% titanium carbide powder and 0.5% yttrium oxide powder by mass to obtain a second nickel-based mixed alloy powder, wherein the particle size of the yttrium oxide powder is 50 nm.

[0041] The second nickel-based mixed alloy powder was fed onto the intermediate wear-resistant layer after cladding with nitrogen at a rate of 15 g / min. Under the parameters of laser power of 1100 W, laser scanning speed of 15 mm / s, laser spot diameter of 3 mm, and laser overlap rate of 45%, nitrogen at a flow rate of 15 L / min was introduced for laser cladding to form a surface wear-resistant layer with a thickness of 1.0 mm on the outside of the intermediate wear-resistant layer.

[0042] S4. After the surface wear-resistant layer is clad, it is slowly cooled to room temperature in the insulation cotton. The surface wear-resistant layer is then polished with a wire brush to remove the floating powder and oxide slag on the surface, resulting in a non-magnetic steel surface wear-resistant strip.

[0043] Example 2 S1. The non-magnetic steel substrate is machined by turning. The surface after turning is degreased and derusted. Then, the surface of the non-magnetic steel substrate is cleaned with acetone cleaning solution. After cleaning, the workpiece is heated with an oxyacetylene flame at a temperature of 125℃.

[0044] A transitional bottom layer nickel-based non-magnetic alloy powder was selected, consisting of 0.05% carbon, 20.57% chromium, 62.02% nickel, 3.86% iron powder, 8.77% molybdenum, 3.73% niobium, 0.3% silicon, 0.11% sulfur, 0.14% phosphorus, and 0.45% manganese by mass, with a particle size of 200-400 mesh.

[0045] Nickel-based non-magnetic alloy powder was fed onto a pretreated non-magnetic steel substrate at a rate of 25 g / min. Under the parameters of laser power of 3500 W, laser scanning speed of 50 mm / s, laser spot diameter of 3 mm, and laser overlap rate of 52.5%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding to obtain a transition underlayer with a thickness of 0.8 mm.

[0046] S2. Mix 79.2% nickel-based alloy powder, 15.0% tungsten carbide powder, 6% titanium carbide powder and 0.8% yttrium oxide powder by mass to obtain the first nickel-based mixed alloy powder. The particle size of the yttrium oxide powder is 60 nm and the particle size of the titanium carbide powder is 120 mesh.

[0047] The first nickel-based mixed alloy powder was fed onto the cladding transition layer at a rate of 20 g / min. Under the parameters of laser power of 2200 W, laser scanning speed of 20 mm / s, laser spot diameter of 3 mm, and laser overlap rate of 47.5%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding, forming an intermediate wear-resistant layer with a thickness of 1.2 mm on the outside of the transition layer.

[0048] S3. Mix 72.2% nickel-based alloy powder, 25.0% tungsten carbide powder, 12.0% titanium carbide powder and 0.8% yttrium oxide powder by mass to obtain a second nickel-based mixed alloy powder with a particle size of 60 nm for the yttrium oxide powder.

[0049] The second nickel-based mixed alloy powder was fed onto the intermediate wear-resistant layer after cladding at a rate of 22 g / min. Under the parameters of laser power of 1500 W, laser scanning speed of 15 mm / s, laser spot diameter of 3 mm, and laser overlap rate of 47.5%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding to form a surface wear-resistant layer with a thickness of 1.5 mm on the outside of the intermediate wear-resistant layer.

[0050] S4. After the surface wear-resistant layer is clad, it is slowly cooled to room temperature in the insulation cotton, and the surface wear-resistant layer is polished with a steel wire wheel to obtain a non-magnetic steel surface wear-resistant belt.

[0051] Example 3 S1. The non-magnetic steel substrate is machined by turning. The surface after turning is degreased and derusted. Then, the surface of the non-magnetic steel substrate is cleaned with acetone cleaning solution. After cleaning, the workpiece is heated with an oxyacetylene flame at a temperature of 50°C.

[0052] A transitional bottom layer nickel-based non-magnetic alloy powder was selected, consisting of 0.1% carbon, 22.05% chromium, 59.0% nickel, 4.0% iron, 10.0% molybdenum, 4.0% niobium, 0.1% silicon, 0.1% sulfur, 0.15% phosphorus, and 0.5% manganese by mass, with a particle size of 200-400 mesh.

[0053] Nickel-based non-magnetic alloy powder was fed onto a pretreated non-magnetic steel substrate at a rate of 45 g / min. Under the parameters of laser power of 3500 W, laser scanning speed of 30 mm / s, laser spot diameter of 5 mm, and laser overlap rate of 55%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding to obtain a transition underlayer with a thickness of 1.0 mm.

[0054] S2. Mix 64.0% nickel-based alloy powder, 25.0% tungsten carbide powder, 10.0% titanium carbide powder and 1.0% yttrium oxide powder by mass to obtain the first nickel-based mixed alloy powder. The particle size of the yttrium oxide powder is 60 nm and the particle size of the titanium carbide powder is 100-270 mesh.

[0055] The first nickel-based mixed alloy powder was fed onto the cladding transition layer at a rate of 30 g / min. Under the parameters of laser power of 2500 W, laser scanning speed of 10 mm / s, laser spot diameter of 5 mm, and laser overlap rate of 50%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding to form an intermediate wear-resistant layer with a thickness of 1.5 mm on the outside of the transition layer.

[0056] S3. Mix 64.0% nickel-based alloy powder, 30% tungsten carbide powder, 15% titanium carbide powder and 1% yttrium oxide powder by mass to obtain a second nickel-based mixed alloy powder with a particle size of 70 nm for the yttrium oxide powder.

[0057] The second nickel-based mixed alloy powder was fed onto the intermediate wear-resistant layer after cladding at a rate of 20 g / min. Under the parameters of laser power of 1200 W, laser scanning speed of 10 mm / s, laser spot diameter of 3 mm, and laser overlap rate of 50%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding to form a surface wear-resistant layer with a thickness of 1.5 mm on the outside of the intermediate wear-resistant layer.

[0058] S4. After the surface wear-resistant layer is clad, it is slowly cooled to room temperature in the insulation cotton, and the surface wear-resistant layer is polished with a steel wire wheel to obtain a non-magnetic steel surface wear-resistant belt.

[0059] Example 4 S1. The non-magnetic steel substrate is machined by turning. The surface after turning is degreased and derusted. Then, the surface of the non-magnetic steel substrate is cleaned with acetone cleaning solution. After cleaning, the workpiece is heated with an oxyacetylene flame to a temperature of 100℃.

[0060] A transitional bottom layer nickel-based non-magnetic alloy powder was selected, consisting of 0.1% carbon, 20.0% chromium, 61.5% nickel, 4.0% iron, 10.0% molybdenum, 4.0% niobium, 0.1% silicon, 0.1% sulfur, 0.1% phosphorus, and 0.1% manganese by mass, with a particle size of 350 mesh.

[0061] Nickel-based non-magnetic alloy powder was fed onto a pretreated non-magnetic steel substrate at a rate of 45 g / min. Under the parameters of laser power of 2800 W, laser scanning speed of 45 mm / s, laser spot diameter of 3 mm, and laser overlap rate of 55%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding to obtain a transition underlayer with a thickness of 0.6 mm.

[0062] S2. Mix 75.0% nickel-based alloy powder, 18.0% tungsten carbide powder, 6.5% titanium carbide powder and 0.5% yttrium oxide powder by mass to obtain the first nickel-based mixed alloy powder. The particle size of the yttrium oxide powder is 80 nm and the particle size of the titanium carbide powder is 100-270 mesh.

[0063] The first nickel-based mixed alloy powder was fed onto the cladding transition layer at a rate of 30 g / min. Under the parameters of laser power of 2100 W, laser scanning speed of 18 mm / s, laser spot diameter of 3 mm, and laser overlap rate of 45%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding, forming an intermediate wear-resistant layer with a thickness of 1.1 mm on the outside of the transition layer.

[0064] S3. Mix 60.0% nickel-based alloy powder, 28.0% tungsten carbide powder, 11.5% titanium carbide powder and 0.5% yttrium oxide powder by mass to obtain a second nickel-based mixed alloy powder. The particle size of the yttrium oxide powder is 90 nm.

[0065] The second nickel-based mixed alloy powder was fed onto the intermediate wear-resistant layer after cladding at a rate of 22 g / min. Under the parameters of laser power of 1800 W, laser scanning speed of 14 mm / s, laser spot diameter of 3 mm, and laser overlap rate of 50%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding to form a surface wear-resistant layer with a thickness of 1.1 mm on the outside of the intermediate wear-resistant layer.

[0066] S4. After the surface wear-resistant layer is clad, it is slowly cooled to room temperature in the insulation cotton, and the surface wear-resistant layer is polished with a steel wire wheel to obtain a non-magnetic steel surface wear-resistant belt.

[0067] Example 5 S1. The non-magnetic steel substrate is machined by turning. The surface after turning is degreased and derusted. Then, the surface of the non-magnetic steel substrate is cleaned with acetone cleaning solution. After cleaning, the workpiece is heated with an oxyacetylene flame at a temperature of 150°C.

[0068] A transitional bottom layer nickel-based non-magnetic alloy powder was selected, consisting of elements with a mass fraction of 0.08% carbon, 23.0% chromium, 62.1% nickel, 3.0% iron, 8.0% molybdenum, 3.3% niobium, 0.1% silicon, 0.1% sulfur, 0.1% phosphorus, and 0.1% manganese, and the particle size of the transitional bottom layer nickel-based non-magnetic alloy powder was 400 mesh.

[0069] Nickel-based non-magnetic alloy powder was fed onto a pretreated non-magnetic steel substrate at a rate of 45 g / min. Under the parameters of laser power of 3200 W, laser scanning speed of 35 mm / s, laser spot diameter of 5 mm, and laser overlap rate of 50%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding to obtain a transition underlayer with a thickness of 0.9 mm.

[0070] S2. Mix 68.0% nickel-based alloy powder, 22.0% tungsten carbide powder, 9.5% titanium carbide powder and 0.5% yttrium oxide powder by mass to obtain the first nickel-based mixed alloy powder. The particle size of the yttrium oxide powder is 100 nm and the particle size of the titanium carbide powder is 100-270 mesh.

[0071] The first nickel-based mixed alloy powder was fed onto the cladding transition layer at a rate of 15 g / min. Under the parameters of laser power of 2400 W, laser scanning speed of 12 mm / s, laser spot diameter of 5 mm, and laser overlap rate of 50%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding, forming an intermediate wear-resistant layer with a thickness of 1.4 mm on the outside of the transition layer.

[0072] S3. Mix 68.0% nickel-based alloy powder, 25.0% tungsten carbide powder, 6.5% titanium carbide powder and 0.5% yttrium oxide powder by mass to obtain a second nickel-based mixed alloy powder. The particle size of the yttrium oxide powder is 100 nm.

[0073] The second nickel-based mixed alloy powder was fed onto the intermediate wear-resistant layer after cladding at a rate of 15 g / min. Under the parameters of laser power of 2800 W, laser scanning speed of 11 mm / s, laser spot diameter of 5 mm, and laser overlap rate of 45%, nitrogen gas with a flow rate of 15 L / min was introduced for laser cladding to form a surface wear-resistant layer with a thickness of 1.4 mm on the outside of the intermediate wear-resistant layer.

[0074] S4. After the surface wear-resistant layer is fused, it is slowly cooled to room temperature in the insulation cotton. The surface wear-resistant layer is then polished with a steel wire wheel to obtain a non-magnetic steel surface wear-resistant belt.

[0075] The non-magnetic steel surface wear-resistant strips prepared in Examples 2 and 3 were subjected to PT flaw detection and metallographic analysis. The metallographic images of the cross-section of the non-magnetic steel surface wear-resistant strips are shown below. Figure 2 As shown in the figure, it can be clearly seen that the cladding layer and the substrate are metallurgically bonded, and the cladding layer is free of defects such as cracks and pores; the hardness test results of Example 2 are as follows. Figure 3 As shown, the non-magnetic steel surface wear-resistant strip of Example 2 has a surface hardness (HV10) of 2885.5, a bonding strength (MPa) of 315, a wear resistance (wear weight loss g / min) of 0.15, and is non-magnetic and free of macroscopic cracks; the non-magnetic steel surface wear-resistant strip of Example 3 has a surface hardness (HV10) of 2920, a bonding strength (MPa) of 330, a wear resistance (wear weight loss g / min) of 0.12, and is non-magnetic and free of macroscopic cracks; the WC coating prepared by conventional methods has a surface hardness (HV10) of 2650, a bonding strength (MPa) of 320, a wear resistance (wear weight loss g / min) of 0.25, and is non-magnetic and free of local microcracks.

[0076] This invention also proposes a wear-resistant strip for a non-magnetic steel surface, such as... Figure 4 As shown, the material prepared by the above preparation method includes a transition layer, an intermediate wear-resistant layer and a surface wear-resistant layer sequentially disposed on the outer wall of the non-magnetic steel substrate. That is, a transition layer is disposed on the outer wall of the non-magnetic steel substrate, an intermediate wear-resistant layer is disposed on the outer wall of the transition layer, and a surface wear-resistant layer is disposed on the outer wall of the intermediate wear-resistant layer.

[0077] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0078] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for preparing a wear-resistant strip on a non-magnetic steel surface by laser cladding, characterized in that, Includes the following steps: S1. The transition bottom layer nickel-based non-magnetic alloy powder is transported onto the pretreated non-magnetic steel substrate and laser cladding is performed to obtain the transition bottom layer; S2. The first nickel-based mixed alloy powder is fed onto the transition bottom cladding layer and laser cladding is performed to form an intermediate wear-resistant layer on the outside of the transition bottom layer. S3. The second nickel-based mixed alloy powder is fed onto the intermediate wear-resistant cladding layer and laser cladding is performed to form a surface wear-resistant layer on the outside of the intermediate wear-resistant layer. S4. After the surface wear-resistant layer is clad, the workpiece is slowly cooled to room temperature in the insulation cotton, and the surface wear-resistant layer is polished to obtain a non-magnetic steel surface wear-resistant strip.

2. The laser cladding method for preparing a wear-resistant strip on a non-magnetic steel surface according to claim 1, characterized in that, The transitional bottom layer nickel-based non-magnetic alloy powder is composed of elements with a mass fraction of 0.05%~0.1% carbon, 20.0%~23.0% chromium, 59%~66.0% nickel, 3.0%~4.0% iron, 8.0%~10.0% molybdenum, 3.0%~4.1% niobium, 0.1%~0.5% silicon, 0.1%~0.15% sulfur, 0.1%~0.15% phosphorus, and 0.1%~0.5% manganese, wherein the sum of the mass fractions of the elements chromium, nickel, iron, molybdenum, niobium, carbon, silicon, phosphorus, and manganese is 100%. The particle size of the transition bottom layer nickel-based non-magnetic alloy powder is 200 mesh to 400 mesh.

3. The laser cladding method for preparing a wear-resistant strip on a non-magnetic steel surface according to claim 1, characterized in that, The first nickel-based mixed alloy powder is obtained by mixing nickel-based alloy powder (64.0%~79.5% by mass), tungsten carbide powder (15.0%~25.0% by mass), titanium carbide powder (5.0%~10.0% by mass), and yttrium oxide powder (0.5%~1.0% by mass), wherein the sum of the mass fractions of the nickel-based alloy powder, the tungsten carbide powder, the titanium carbide powder, and the yttrium oxide powder is 100%. The second nickel-based mixed alloy powder is obtained by mixing nickel-based alloy powder (55.0%~74.5% by mass), tungsten carbide powder (20.0%~30.0% by mass), titanium carbide powder (5.0%~15.0% by mass), and yttrium oxide powder (0.5%~1.0% by mass), wherein the sum of the mass fractions of the nickel-based mixed alloy powder, the tungsten carbide powder, the titanium carbide powder, and the yttrium oxide powder is 100%. The nickel-based alloy powder is composed of 0.03% carbon, 5.00% chromium, 89.97% nickel, 1.00% silicon, 0.50% iron, 0.50% boron, 2.4% molybdenum, and 0.6% niobium by mass fraction.

4. The laser cladding method for preparing a wear-resistant strip on a non-magnetic steel surface according to claim 1, characterized in that, In step S1, nickel-based non-magnetic alloy powder is clad onto the outer wall of a pretreated non-magnetic steel substrate under the conditions of laser power of 2500W~3500W, laser scanning speed of 30mm / s~50mm / s, laser spot diameter of 3mm~5mm, and laser overlap rate of 50%~55% to form a transition layer with a thickness of 0.5mm~1.0mm.

5. The laser cladding method for preparing a wear-resistant strip on a non-magnetic steel surface according to claim 1, characterized in that, In S2, the first nickel-based mixed alloy powder is clad onto the transition substrate to form an intermediate wear-resistant layer with a thickness of 1.0 mm to 1.5 mm under the conditions of laser power of 2000 W to 2500 W, laser scanning speed of 10 mm / s to 20 mm / s, laser spot diameter of 3 mm to 5 mm, and laser overlap rate of 45% to 50%.

6. The laser cladding method for preparing a wear-resistant strip on a non-magnetic steel surface according to claim 1, characterized in that, In S3, the second nickel-based mixed alloy powder is clad onto the intermediate wear-resistant layer to form a surface wear-resistant layer with a thickness of 1.0 mm to 1.5 mm under the conditions of laser power of 1100 W to 2100 W, laser scanning speed of 10 mm / s to 15 mm / s, laser spot diameter of 3 mm to 5 mm, and laser overlap rate of 45% to 50%.

7. The laser cladding method for preparing a wear-resistant strip on a non-magnetic steel surface according to claim 1, characterized in that, In step S1, the powder is fed at a rate of 24 g / min to 45 g / min; in steps S2 and S3, the powder is fed at a rate of 15 g / min to 30 g / min. In S1~S3, nitrogen gas with a flow rate of 15~20L / min is used as a protective gas during the laser cladding process.

8. The laser cladding method for preparing a wear-resistant strip on a non-magnetic steel surface according to claim 1, characterized in that, In step S1, the pretreatment of the non-magnetic steel substrate includes: The non-magnetic steel substrate is machined by turning. The machined surface is then degreased and derusted. The surface of the non-magnetic steel substrate is then cleaned with acetone cleaning solution. After cleaning, the workpiece is heated with an oxyacetylene flame at a temperature of 100℃~150℃.

9. A wear-resistant strip for a non-magnetic steel surface, prepared by the method described in any one of claims 1 to 9, characterized in that, It includes a transition layer, an intermediate wear-resistant layer and a surface wear-resistant layer, which are sequentially arranged on the non-magnetic steel substrate.

10. An application of the wear-resistant strip on the surface of non-magnetic steel as described in claim 9, characterized in that, The non-magnetic steel surface wear-resistant strip is used in oil drill collars.

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