A method for preparing wear-resistant and corrosion-resistant coating for X80 pipeline steel

Abstract

This invention relates to the field of material surface modification treatment and discloses a method for preparing a wear-resistant and corrosion-resistant coating for X80 pipeline steel. The invention includes the following steps: taking nickel, chromium, molybdenum, tungsten, iron, titanium, carbon, and rare earth elements, and preparing alloy powder using gas atomization; performing a first pretreatment on the alloy powder; performing a second pretreatment on the pipeline steel surface; and then using the pretreated alloy powder to clad the treated pipeline steel surface with an alloy coating via a high-speed laser cladding process. This invention, by designing a coating material with high wear and corrosion resistance and combining it with a suitable high-speed laser cladding technology, achieves high-quality preparation of a coating on the pipeline steel surface, obtaining an alloy coating with strong wear and corrosion resistance. This has significant scientific and engineering application value for improving the safety and service life of pipeline steel.

Description

Technical Field

[0001] This invention relates to the field of material surface modification technology, and more specifically, to a method for preparing a wear-resistant and corrosion-resistant coating for X80 pipeline steel. Background Technology

[0002] Oil and natural gas are vital energy sources, and their stable transportation and supply are indispensable for ensuring my country's energy security. However, due to their complex operating environment and harsh application conditions, corrosion of oil and gas pipelines is a major challenge facing the oil and gas industry today. Currently, over 70% of the world's developing oil and gas fields are highly corrosive. This environment not only increases the development costs of oil and gas fields but also further escalates facility maintenance and management costs. As of 2020, my country had approximately 17,000 km of buried pipelines, ranking first in the world. It is not uncommon for underground oil and gas pipelines in my country to experience corrosion perforation within 1-2 years of operation. This not only causes oil and gas leaks due to perforation, but also wastes materials and manpower due to maintenance, and losses due to production stoppages. Furthermore, corrosion can lead to fires, especially explosions in finished oil pipelines, threatening personal safety and polluting the environment, with extremely serious consequences. X80 high-strength pipeline steel is considered the preferred steel for future natural gas transmission pipelines; therefore, research on surface modification of X80 pipeline steel to improve its corrosion resistance is of great significance.

[0003] Currently, corrosion protection for long-distance pipelines in China has gradually shifted from petroleum asphalt, coal tar enamel, or epoxy coal tar to fusion-bonded epoxy powder (FBE) and polyethylene three-layer composite (3PE) coatings. However, the bonding between these protective coatings and the substrate is primarily mechanical, resulting in low strength, susceptibility to damage, peeling, and aging. Pipeline steel is easily bumped and scratched during transportation and installation, leading to coating detachment, scratches, corrosion, perforation, and leaks, causing significant property damage to companies and harm to the public and the environment. Therefore, traditional coating protection technologies are no longer suitable for protecting pipeline steel in complex environments.

[0004] In recent years, the development of laser technology has provided us with a new approach to pipeline steel repair. Laser cladding, as a surface modification technology, has wide applications in coating preparation. Compared with other coating preparation technologies, laser cladding has unique advantages, such as precision and ease of control during processing, accurate control of the effective heat flow in the processing area, avoiding excessive thermal damage to areas outside the target region, and reducing cracks caused by uneven thermal stress distribution. Furthermore, the coating prepared by laser cladding can form a stable metallurgical interface with the substrate. In addition, the high cooling rate of laser cladding can also make the coating grains finer, thus playing a strengthening role. Therefore, using laser cladding technology to repair and enhance the performance of X80 pipeline steel has a very broad application prospect.

[0005] However, traditional alloys used for surface modification face severe challenges in the face of complex soil environments and increasing requirements for various properties such as surface hardness, toughness, wear resistance, and corrosion resistance.

[0006] Therefore, the present invention proposes a method for preparing a wear-resistant and corrosion-resistant coating for X80 pipeline steel, which has important practical significance. Summary of the Invention

[0007] In view of this, the present invention proposes a method for preparing a wear-resistant and corrosion-resistant coating for X80 pipeline steel, in order to solve the problems of poor wear and corrosion resistance and short service life of existing X80 pipeline steel. This invention proposes a wear-resistant and corrosion-resistant coating for X80 pipeline steel, comprising alloy powder in parts by weight: Nickel 60.18-68.74 parts, chromium 12-14 parts, molybdenum 12-15 parts, tungsten 5-6 parts, iron 2-4 parts, titanium 0.1-0.3 parts, carbon 0.01-0.02 parts, and rare earth 0.15-0.5 parts.

[0008] Preferably, the rare earth element is lanthanum and yttrium, wherein the mass ratio of lanthanum to yttrium is 2:3.

[0009] Preferably, the alloy powder has a sphericity ≥90% and a particle size of 45-105μm.

[0010] This invention also provides a method for preparing a wear-resistant and corrosion-resistant coating for X80 pipeline steel, comprising the following steps: Nickel, chromium, molybdenum, tungsten, iron, titanium, carbon, and rare earth elements are used to prepare alloy powders via gas atomization. The alloy powder is subjected to a first pretreatment; The pipeline steel surface undergoes a second pretreatment, and the treated alloy powder is used to clad the treated pipeline steel surface with an alloy coating through a high-speed laser cladding process.

[0011] Furthermore, the first pretreatment specifically involves treating the alloy powder at 150-200°C for 60-240 minutes.

[0012] Furthermore, the second pretreatment specifically involves: grinding the surface of the pipeline steel with sandpaper of progressively finer texture, controlling the roughness to be between 45-65 μm, and then cleaning it with alcohol.

[0013] Furthermore, the laser power of the high-speed laser cladding process is 2.4-3.6kW, the scanning speed is 4-8cm / s, the powder feeding speed is 0.6-1.0r / min, and the overlap rate is 40%-50%.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention achieves high-quality preparation of coatings on pipeline steel surfaces by designing highly wear-resistant and corrosion-resistant coating materials and combining them with high-speed laser cladding technology. This results in alloy coatings with strong wear and corrosion resistance, which has significant scientific and engineering application value for improving the safety and service life of pipeline steel.

[0015] The present invention provides a method for preparing wear-resistant and corrosion-resistant coatings for X80 pipeline steel. By designing coating materials with high wear and corrosion resistance and combining them with high-speed laser cladding technology, the method achieves high-quality preparation of coatings on the surface of pipeline steel and obtains alloy coatings with strong wear and corrosion resistance.

[0016] The present invention uses the above method to prepare X80 pipeline steel coating, which has good wear resistance and corrosion resistance. At the same time, the method of the present invention is simple to operate, has low production cost, and can be mass-produced on a large scale. Detailed Implementation

[0017] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0018] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included within this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0019] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0020] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0021] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0022] This invention provides a wear-resistant and corrosion-resistant coating for X80 pipeline steel, comprising alloy powder in parts by weight: Nickel 60.18-68.74 parts, chromium 12-14 parts, molybdenum 12-15 parts, tungsten 5-6 parts, iron 2-4 parts, titanium 0.1-0.3 parts, carbon 0.01-0.02 parts, and rare earth 0.15-0.5 parts.

[0023] Preferably, the wear-resistant and corrosion-resistant coating for X80 pipeline steel comprises, by weight, parts of alloy powder: Nickel 64.585 parts, chromium 13 parts, molybdenum 14 parts, tungsten 5.5 parts, iron 2.5 parts, titanium 0.15 parts, carbon 0.015 parts, and rare earth 0.25 parts.

[0024] Understandably, nickel, as a matrix element, provides good plasticity, toughness, and high-temperature stability, ensuring the coating's resistance to deformation and its thermal compatibility with the X80 steel substrate. Chromium dissolves in the nickel matrix and forms a dense Cr2O3 passivation film on the surface, blocking the penetration of corrosive media. Simultaneously, it generates Cr7C3 and Cr... 23 C6 hard phase enhances resistance to abrasive wear; Molybdenum enhances the strength of the matrix through solid solution strengthening, while inhibiting pitting and crevice corrosion caused by chloride ions, making it suitable for service environments of oil and gas transportation containing sulfur and chloride. Tungsten forms high-hardness intermetallic compounds such as W2C, which significantly improves the macroscopic hardness and wear resistance of the coating, while also increasing the high-temperature strength of the alloy. Iron is used to adjust the coefficient of thermal expansion of the alloy, reduce the difference in thermal expansion between the coating and X80 pipeline steel, and reduce the thermal stress and cracking risk during the cladding cooling process. Titanium is a strong carbide-forming element, generating nanoscale TiC dispersed phases, while inhibiting grain growth through pinning effect to achieve fine grain strengthening. Trace amounts of carbon combine with chromium, titanium, and tungsten to form hard carbides, improving wear resistance without sacrificing toughness; the extremely low carbon content prevents coating embrittlement. Rare earth elements play a role in microalloying, purifying grain boundaries, refining solidification structure, and improving the wettability of liquid alloys.

[0025] In this invention, the rare earth elements are lanthanum and yttrium, wherein the mass ratio of lanthanum to yttrium is 2:3.

[0026] It is understandable that the microalloying effects of lanthanum and yttrium are complementary and differentiated, with a 2:3 ratio achieving optimal synergy. Lanthanum has stronger surface activity and its core function is to purify the alloy melt. It combines with impurities such as sulfur and oxygen to form high-melting-point rare earth inclusions, eliminates low-melting-point harmful phases at grain boundaries, and improves the wettability of the liquid alloy in the molten pool to the matrix. Yttrium has a more significant grain-refining and strengthening effect. It inhibits dendrite growth during solidification through the compositional supercooling effect, refines the solidification structure of the coating, and enhances the grain boundary bonding strength. At a 2:3 ratio, the purification effect of lanthanum and the grain-refining effect of yttrium are balanced, avoiding both the coarsening of rare earth inclusions caused by excessive addition of lanthanum and the grain boundary embrittlement caused by excessive addition of yttrium.

[0027] In this invention, the sphericity of the alloy powder is ≥90%, and the particle size is 45-105μm.

[0028] Understandably, high sphericity ensures smooth powder flow in the powder feeding pipeline, stable and uniform powder feeding rate, avoids problems such as powder blockage, powder breakage, and powder feeding fluctuation, and at the same time, the powder flight trajectory is controllable, the powder landing point in the molten pool is precise, and the consistency of the molten channel formation is guaranteed. The optimal particle size range for high-speed laser cladding is 45~105μm: if the particle size is too fine, the powder has a large specific surface area, and it is easy to burn and splatter under laser irradiation, which reduces the utilization rate and increases the risk of porosity; if the particle size is too coarse, the laser energy is not enough to fully melt the powder, and internal defects such as incomplete fusion and inclusions are likely to occur.

[0029] This invention also provides a method for preparing a wear-resistant and corrosion-resistant coating for X80 pipeline steel, comprising the following steps: Nickel, chromium, molybdenum, tungsten, iron, titanium, carbon, and rare earth elements are used to prepare alloy powders via gas atomization. The alloy powder is subjected to a first pretreatment; The pipeline steel surface undergoes a second pretreatment, and the treated alloy powder is used to clad the treated pipeline steel surface with an alloy coating through a high-speed laser cladding process.

[0030] It is understood that this invention achieves high-quality preparation of coatings on pipeline steel surfaces by designing highly wear-resistant and corrosion-resistant coating materials and combining them with high-speed laser cladding technology, thereby obtaining alloy coatings with strong wear and corrosion resistance. This has significant scientific and engineering application value for improving the safety and service life of pipeline steel.

[0031] It is understood that the method for preparing wear-resistant and corrosion-resistant coatings for X80 pipeline steel provided by the present invention achieves high-quality preparation of coatings on the surface of pipeline steel by designing coating materials with high wear resistance and corrosion resistance and combining them with high-speed laser cladding technology, thereby obtaining alloy coatings with strong wear resistance and corrosion resistance.

[0032] It is understood that the X80 pipeline steel coating prepared by the above method has good wear and corrosion resistance. At the same time, the method of the present invention is simple to operate, has low production cost, and can be mass-produced on a large scale.

[0033] In this invention, the first pretreatment specifically involves treating the alloy powder at 150-200°C for 60-240 minutes.

[0034] Understandably, a temperature range of 150~200℃ can completely remove physically adsorbed water from the powder surface without causing powder oxidation or volatilization of alloying elements. A heat preservation time of 60~240 minutes ensures uniform heating inside the powder pile, complete removal of moisture, and avoids surface drying while leaving moisture inside. The vacuum environment prevents the powder from oxidizing at high temperatures and lowers the boiling point of water, thus improving drying efficiency and thoroughness.

[0035] This pretreatment can prevent moisture from vaporizing at high temperatures during the cladding process, which could lead to defects such as coating porosity, spatter, and hydrogen-induced cracking.

[0036] In this invention, a uniform rough surface can be obtained by grinding from coarse to fine, avoiding excessively deep scratches or uneven surfaces caused by grinding with a single type of sandpaper, while gradually removing the surface defect layer. A roughness of 45~65μm can create a mechanical anchoring effect, improve the physical bonding between the coating and the substrate, and ensure that the liquid alloy in the molten pool spreads well on the surface; if the roughness is too low, the bonding force will be insufficient, and if it is too high, air and impurities will easily remain in the pits, forming interface defects. Alcohol cleaning can effectively remove surface organic contaminants and grinding debris, ensuring a clean substrate surface, preventing impurities from entering the molten pool and forming inclusions, and ensuring the quality of metallurgical bonding.

[0037] In this invention, the laser power of the high-speed laser cladding process is 2.4-3.6kW, the scanning speed is 4-8cm / s, the powder feeding speed is 0.6-1.0r / min, and the overlap rate is 40%-50%.

[0038] Understandably, the laser power and scanning speed together determine the heat input per unit length: a power of 2.4~3.6kW matched with a scanning speed of 4~8cm / s can ensure that the powder is fully melted, while the heat input to the substrate is moderate, and the cladding dilution rate is controlled at 3%~5%, avoiding the large amount of substrate elements mixed in and diluting the coating performance. The powder feeding speed is matched with the energy input to ensure that the aspect ratio of the single-pass cladding layer is appropriate (about 0.2~0.3), the forming is flat, and to avoid the powder feeding speed being too fast, which would lead to incomplete fusion, or the powder feeding speed being too slow, which would lead to overheating of the substrate. An overlap rate of 40% to 50% can ensure a smooth and continuous surface after multiple cladding passes, and that the overlap area is fully remelted and fused, avoiding overlap depressions and unfused steps, while also avoiding heat accumulation and efficiency reduction caused by an excessively high overlap rate.

[0039] Example 1 S1. The alloy powder prepared by gas atomization consists of the following components by weight: 64.585 parts nickel, 13 parts chromium, 14 parts molybdenum, 5.5 parts tungsten, 2.5 parts iron, 0.15 parts titanium, 0.015 parts carbon, 0.1 parts lanthanum, and 0.15 parts yttrium; wherein the mass ratio of lanthanum to yttrium in the alloy powder is 2:3, the total mass of rare earth elements is controlled at 0.25 parts, and the sphericity of the alloy powder is ≥90%, with a particle size of 45-105 μm; S2. Treat the alloy powder at 180°C for 120 min; S3. Grind the surface of the pipeline steel with sandpaper from coarse to fine in sequence, and control the roughness to 45-65μm. After grinding, clean it with alcohol and set it aside for use. S4. Using high-speed laser cladding equipment, the alloy powder after laser cladding treatment is applied to the treated pipeline steel to form an alloy coating with excellent corrosion resistance. The high-speed laser cladding process conditions are set as follows: laser power 3.6kW, scanning speed 6cm / s, powder feeding speed 0.8r / min, and overlap rate 50%.

[0040] Example 2 S1. The alloy powder prepared by gas atomization consists of the following components by weight: 63.01 parts nickel, 13.5 parts chromium, 14 parts molybdenum, 6 parts tungsten, 3 parts iron, 0.2 parts titanium, 0.02 parts carbon, 0.1 parts lanthanum, and 0.15 parts yttrium; wherein the mass ratio of lanthanum to yttrium in the alloy powder is 2:3, the total mass of rare earth elements is controlled at 0.25 parts, and the sphericity of the alloy powder is ≥90%, with a particle size of 45-105 μm; S2. Treat the alloy powder at 180°C for 120 min; S3. Grind the surface of the pipeline steel with sandpaper from coarse to fine in sequence, and control the roughness to 45-65μm. After grinding, clean it with alcohol and set it aside for use. S4. Using high-speed laser cladding equipment, the alloy powder after laser cladding treatment is applied to the treated pipeline steel to form an alloy coating with excellent corrosion resistance. The high-speed laser cladding process conditions are set as follows: laser power 3.6kW, scanning speed 6cm / s, powder feeding speed 0.8r / min, and overlap rate 50%.

[0041] Example 3 S1. The alloy powder prepared by gas atomization consists of the following components by weight: 60.18 parts nickel, 14 parts chromium, 15 parts molybdenum, 6 parts tungsten, 4 parts iron, 0.3 parts titanium, 0.02 parts carbon, 0.2 parts lanthanum, and 0.3 parts yttrium; wherein the mass ratio of lanthanum to yttrium in the alloy powder is 2:3, and the total mass of rare earth elements is controlled at 0.5 parts. S2. Treat the alloy powder at 180°C for 120 min; S3. Grind the surface of the pipeline steel with sandpaper from coarse to fine in sequence, and control the roughness to 45-65μm. After grinding, clean it with alcohol and set it aside for use. S4. Using high-speed laser cladding equipment, the alloy powder after laser cladding treatment is applied to the treated pipeline steel to form an alloy coating with excellent corrosion resistance. The high-speed laser cladding process conditions are set as follows: laser power 3.6kW, scanning speed 6cm / s, powder feeding speed 0.8r / min, and overlap rate 50%.

[0042] Example 4 S1. The alloy powder prepared by gas atomization consists of the following components by weight: 68.74 parts nickel, 14 parts chromium, 15 parts molybdenum, 6 parts tungsten, 4 parts iron, 0.3 parts titanium, 0.02 parts carbon, 0.2 parts lanthanum, and 0.3 parts yttrium; wherein the mass ratio of lanthanum to yttrium in the alloy powder is 2:3, and the total mass of rare earth elements is controlled at 0.5 parts. S2. The alloy powder is treated at 200°C for 240 min; S3. Grind the surface of the pipeline steel with sandpaper from coarse to fine in sequence, and control the roughness to 45-65μm. After grinding, clean it with alcohol and set it aside for use. S4. Using high-speed laser cladding equipment, the alloy powder after laser cladding treatment is applied to the treated pipeline steel to form an alloy coating with excellent corrosion resistance. The high-speed laser cladding process conditions are set as follows: laser power 3.6kW, scanning speed 8cm / s, powder feeding speed 1r / min, and overlap rate 50%.

[0043] Example 5 S1. The alloy powder prepared by gas atomization consists of the following components by weight: 60.18 parts nickel, 12 parts chromium, 12 parts molybdenum, 5 parts tungsten, 2 parts iron, 0.1 parts titanium, 0.01 parts carbon, 0.06 parts lanthanum, and 0.09 parts yttrium; wherein the mass ratio of lanthanum to yttrium in the alloy powder is 2:3, and the total mass of rare earth elements is controlled at 0.15 parts. S2. Treat the alloy powder at 150°C for 60 min; S3. Grind the surface of the pipeline steel with sandpaper from coarse to fine in sequence, and control the roughness to 45-65μm. After grinding, clean it with alcohol and set it aside for use. S4. Using high-speed laser cladding equipment, the alloy powder after laser cladding treatment is applied to the treated pipeline steel to form an alloy coating with excellent corrosion resistance. The high-speed laser cladding process conditions are set as follows: laser power 2.4kW, scanning speed 4cm / s, powder feeding speed 0.6r / min, and overlap rate 40%.

[0044] Comparative Example 1 S1. The alloy powder prepared by gas atomization consists of the following components by weight: 64.585 parts nickel, 13 parts chromium, 14 parts molybdenum, 5.5 parts tungsten, 2.5 parts iron, 0.15 parts titanium, and 0.015 parts carbon, wherein the sphericity of the alloy powder is ≥90% and the particle size is 45-105μm. S2. Treat the alloy powder at 180°C for 120 min; S3. Grind the surface of the pipeline steel with sandpaper from coarse to fine in sequence, and control the roughness to 45-65μm. After grinding, clean it with alcohol and set it aside for use. S4. Using high-speed laser cladding equipment, the alloy powder after laser cladding treatment is applied to the treated pipeline steel to form an alloy coating. The high-speed laser cladding process conditions are set as follows: laser power 3.6kW, scanning speed 6cm / s, powder feeding speed 0.8r / min, and overlap rate 50%.

[0045] Comparative Example 2 S1. The alloy powder prepared by gas atomization consists of the following components by weight: 64.585 parts nickel, 13 parts chromium, 14 parts molybdenum, 5.5 parts tungsten, 2.5 parts iron, 0.15 parts titanium, 0.015 parts carbon, and 0.1 parts lanthanum; wherein the total mass of rare earth is controlled at 0.1 parts, and the sphericity of the alloy powder is ≥90%, and the particle size is 45-105 μm; S2. Treat the alloy powder at 180°C for 120 min; S3. Grind the surface of the pipeline steel with sandpaper from coarse to fine in sequence, and control the roughness to 45-65μm. After grinding, clean it with alcohol and set it aside for use. S4. Using high-speed laser cladding equipment, the alloy powder after laser cladding treatment is applied to the treated pipeline steel to form an alloy coating. The high-speed laser cladding process conditions are set as follows: laser power 3.6kW, scanning speed 6cm / s, powder feeding speed 0.8r / min, and overlap rate 50%.

[0046] Comparative Example 3 S1. The alloy powder prepared by gas atomization consists of the following components by weight: 64.585 parts nickel, 13 parts chromium, 14 parts molybdenum, 5.5 parts tungsten, 2.5 parts iron, 0.15 parts titanium, 0.015 parts carbon, 0.1 parts lanthanum, and 0.15 parts yttrium; wherein the mass ratio of lanthanum to yttrium in the alloy powder is 2:3, the total mass of rare earth elements is controlled at 0.25 parts, and the sphericity of the alloy powder is ≥90%, with a particle size of 45-105 μm; S2. Treat the alloy powder at 180°C for 120 min; S3. Grind the surface of the pipeline steel with sandpaper from coarse to fine in sequence, and control the roughness to 45-65μm. After grinding, clean it with alcohol and set it aside for use. S4. Using high-speed laser cladding equipment, the alloy powder after laser cladding treatment is applied to the treated pipeline steel to form an alloy coating. The high-speed laser cladding process conditions are set as follows: laser power 1.6kW, scanning speed 6cm / s, powder feeding speed 1.2r / min, and overlap rate 50%.

[0047] Comparative Example 4 S1. The alloy powder prepared by gas atomization consists of the following components by weight: 64.585 parts nickel, 13 parts chromium, 14 parts molybdenum, 5.5 parts tungsten, 2.5 parts iron, 0.15 parts titanium, 0.015 parts carbon, 0.1 parts lanthanum, and 0.15 parts yttrium; wherein the mass ratio of lanthanum to yttrium in the alloy powder is 2:3, the total mass of rare earth elements is controlled at 0.25 parts, and the sphericity of the alloy powder is ≥90%, with a particle size of 45-105 μm; S2. Treat the alloy powder at 180°C for 120 min; S3. Grind the surface of the pipeline steel with sandpaper from coarse to fine in sequence, and control the roughness to 45-65μm. After grinding, clean it with alcohol and set it aside for use. S4. Using high-speed laser cladding equipment, the alloy powder after laser cladding treatment is applied to the treated pipeline steel to form an alloy coating. The high-speed laser cladding process conditions are set as follows: laser power 3.6kW, scanning speed 6cm / s, powder feeding speed 1.2r / min, and overlap rate 50%.

[0048] Comparative Example 5 Corrosion resistance test analysis was performed on the X80 pipeline steel substrate.

[0049] Performance testing The laser cladding coatings prepared in Examples 1-3 and Comparative Examples 1-5 were tested. The test results are shown in Table 1.

[0050] Table 1. Performance test results of diamond-copper matrix composite materials obtained in the examples and comparative examples.

[0051] As shown in Table 1, compared with the diamond copper-based composite materials prepared in Comparative Examples 1-5, the diamond copper-based composite materials prepared in Examples 1-4 of this invention have significantly improved density and thermal conductivity, with a density of 97.92-98.22% and a thermal conductivity of 736-807 W / (m·K), which greatly meets the requirements for the use of high thermal conductivity thermal management materials.

[0052] As can be seen, the coating prepared using the method of the present invention has a self-corrosion current density of 5.1310. -6 A.cm -2 The self-corrosion potential is -0.465V. Therefore, this invention can provide a new research and development direction and technical support for the development of corrosion-resistant coatings for X80 pipeline steel.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A wear-resistant and corrosion-resistant coating for X80 pipeline steel, characterized in that, Including alloy powder in parts by mass: Nickel 60.18-68.74 parts, chromium 12-14 parts, molybdenum 12-15 parts, tungsten 5-6 parts, iron 2-4 parts, titanium 0.1-0.3 parts, carbon 0.01-0.02 parts, and rare earth 0.15-0.5 parts.

2. The wear-resistant and corrosion-resistant coating for X80 pipeline steel according to claim 1, characterized in that, The rare earth elements are lanthanum and yttrium, wherein the mass ratio of lanthanum to yttrium is 2:

3.

3. The wear-resistant and corrosion-resistant coating for X80 pipeline steel according to claim 1, characterized in that, The alloy powder has a sphericity of ≥90% and a particle size of 45-105μm.

4. The method for preparing an X80 pipeline steel wear-resistant and corrosion-resistant coating as described in any one of claims 1-3, characterized in that, Includes the following steps: Nickel, chromium, molybdenum, tungsten, iron, titanium, carbon, and rare earth elements are used to prepare alloy powders via gas atomization. The alloy powder is subjected to a first pretreatment; The pipeline steel surface undergoes a second pretreatment, and the treated alloy powder is used to clad the treated pipeline steel surface with an alloy coating through a high-speed laser cladding process.

5. The method for preparing an X80 pipeline steel wear-resistant and corrosion-resistant coating according to claim 4, characterized in that, The first pretreatment specifically involves treating the alloy powder at 150-200°C for 60-240 minutes.

6. The method for preparing an X80 pipeline steel wear-resistant and corrosion-resistant coating according to claim 4, characterized in that, The second pretreatment specifically involves: grinding the surface of the pipeline steel with sandpaper of progressively finer texture, controlling the roughness to be between 45-65μm, and then cleaning it with alcohol.

7. The method for preparing an X80 pipeline steel wear-resistant and corrosion-resistant coating according to claim 4, characterized in that, The laser power of the high-speed laser cladding process is 2.4-3.6kW, the scanning speed is 4-8cm / s, the powder feeding speed is 0.6-1.0r / min, and the overlap rate is 40%-50%.

Images