阅读说明：本技术 一种耐磨耐蚀石油管道及其制备方法 (Wear-resistant corrosion-resistant petroleum pipeline and preparation method thereof ) 是由 王宁 刘可峰 李丽 刘宪福 白雪 于 2021-10-08 设计创作，主要内容包括：本发明公开了一种耐磨耐蚀石油管道及其制备方法,属于石油管道技术领域,其包括钢管本体,特征在于：所述钢管本体的内壁上自外至内依次设有NiCrAlY层、第一陶瓷层、第二陶瓷层和聚四氟乙烯层,第一陶瓷层和第二陶瓷层由粒径为32～38μm的Al-(2)O-(3)-13%TiO-(2)颗粒构成,第一陶瓷层孔隙率≤4%,第二陶瓷层15%≤孔隙率≤20%。此管中第一陶瓷层具有硬度高且致密的特性,能够阻隔管内液体,提高管道的耐磨与耐蚀性,在第一陶瓷层烧结同材质的第二陶瓷层则较第一陶瓷层疏松,一方面与第一陶瓷层具有很高的结合强度,另一方面增大了与聚四氟乙烯层的结合强度,并且与聚四氟乙烯颗粒形成微纳米二元粗糙度结构,易于制得具有疏水特性的微纳结构,提高管体内壁的疏水性,增强耐蚀性能。(The invention discloses a wear-resistant corrosion-resistant petroleum pipeline and a preparation method thereof, belongs to the technical field of petroleum pipelines, and comprises a steel pipe body, and is characterized in thatIn the following steps: the inner wall of the steel pipe body is sequentially provided with a NiCrAlY layer, a first ceramic layer, a second ceramic layer and a polytetrafluoroethylene layer from outside to inside, and the first ceramic layer and the second ceramic layer are made of Al with the grain size of 32-38 mu m 2 O 3 ‑13%TiO 2 The porosity of the first ceramic layer is less than or equal to 4 percent, and the porosity of the second ceramic layer is less than or equal to 20 percent and more than or equal to 15 percent. First ceramic layer has the high and fine and close characteristic of hardness in this pipe, can separate intraductal liquid, the wear-resisting and the corrosion resistance of pipeline are improved, it is then loose than first ceramic layer at the second ceramic layer of first ceramic layer sintering with the material, on the one hand have very high bonding strength with first ceramic layer, on the other hand increased with the bonding strength on polytetrafluoroethylene layer, and form micro-nano binary roughness structure with the polytetrafluoroethylene granule, easily make the micro-nano structure that has hydrophobic characteristic, improve the hydrophobicity of body inner wall, reinforcing corrosion resistance.)

1. The utility model provides a wear-resisting corrosion-resistant petroleum pipeline, includes the steel pipe body, its characterized in that: the inner wall of the steel pipe body is sequentially provided with a NiCrAlY layer, a first ceramic layer, a second ceramic layer and a polytetrafluoroethylene layer from outside to inside, and the first ceramic layer and the second ceramic layer are made of Al with the grain size of 32-38 mu m₂O₃-13%TiO₂The porosity of the first ceramic layer is less than or equal to 4 percent, and the porosity of the second ceramic layer is less than or equal to 20 percent and more than or equal to 15 percent.

2. The wear and corrosion resistant petroleum pipeline of claim 1 wherein: the NiCrAlY layer is formed by plasma spraying of NiCrAlY particles with the particle size of 15-45 mu m.

3. A wear and corrosion resistant petroleum pipeline according to claim 1 or 2, characterized in that: the thickness of the NiCrAlY layer is 50 mu m, the thickness of the first ceramic layer is 150 mu m, the thickness of the second ceramic layer is 50 mu m, and the thickness of the polytetrafluoroethylene layer is 5 mu m.

4. A preparation method of a wear-resistant corrosion-resistant petroleum pipeline is characterized by comprising the following steps: the method comprises the following steps:

(1) fixing a pipe body: horizontally fixing the steel pipe body on a rotary table, wherein the steel pipe body rotates at a linear speed of 0.2 m/s;

(2) preparation of a NiCrAlY layer: carrying out plasma spraying on NiCrAlY particles with the particle size of 15-45 mu m on the inner wall of the steel pipe body in the step (1) to form a NiCrAlY layer, wherein the spraying power is 40 kW, the spraying distance is 120 mm, the powder delivery rate is 20 g/min, the argon flow rate is 50L/min, and the hydrogen flow rate is 5.5L/min;

(3) preparing a first ceramic layer: plasma spraying Al with the particle size of 32-38 mu m on the NiCrAlY layer prepared in the step (2)₂O₃-13%TiO₂Granulating to obtain a first ceramic layer; the spraying power is 42 kW, the spraying distance is 120 mm, the powder feeding amount is 25 g/min, the argon flow is 50L/min, the hydrogen flow is 5.5L/min, and Al is added₂O₃-13%TiO₂The average particle diameter of the particles was 35 μm;

(4) preparing a second ceramic layer: plasma spraying Al with the particle size of 32-38 mu m on the first ceramic layer prepared in the step (3)₂O₃-13%TiO₂Granulating to obtain a second ceramic layer; the spraying power is 42 kW, the spraying distance is 180 mm, the powder feeding amount is 20 g/min, the argon flow is 50L/min, the hydrogen flow is 5.5L/min, and Al is added₂O₃-13%TiO₂The average particle diameter of the particles was 35 μm;

(5) preparing a composite solution: adding a KH550 coupling agent into 60 mass percent of PTFE dispersion liquid to obtain a mixed solution, wherein the mass percent of the KH550 coupling agent in the mixed solution is 1%, then adding deionized water into the mixed solution to dilute until the mass percent of PTFE in the mixed solution is 20%, then ultrasonically oscillating and stirring for 15min at the stirring speed of 150-200 r/min, and then standing for half an hour to obtain a PTFE composite solution; the particle size of PTFE particles in the dispersion liquid is 170-230 nm, and the average particle size is 200 nm;

(6) preparing a polytetrafluoroethylene layer: spraying the PTFE composite solution prepared in the step (5) on the second ceramic layer prepared in the step (4) through a high-pressure spray gun to prepare a polytetrafluoroethylene layer, wherein the caliber of the spray gun is 1mm, the width of a spray width is 100mm, the spraying pressure is 0.3-0.5 MPa, and the spraying distance is 150 mm;

(7) and (3) sintering: and (4) airing the steel pipe body treated in the step (6) at room temperature for 2 hours, then carrying out blast type drying at 100 ℃ for 10 minutes, then putting the steel pipe body into a drying furnace, gradually heating the drying furnace from room temperature to 330 ℃ within 45 minutes, carrying out constant temperature sintering for 1 hour, and slowly cooling the drying furnace to room temperature to obtain the wear-resistant and corrosion-resistant petroleum pipe.

5. The method for making a wear and corrosion resistant petroleum pipeline as recited in claim 4 wherein: in the steps (2) - (4), spraying is carried out by an inner hole spray gun.

6. The method for making a wear and corrosion resistant petroleum pipeline as recited in claim 5 wherein: in the steps (2) - (4), after spraying for a circle, the axial moving distance of the inner hole spray gun along the steel pipe body is 10-15 mm.

7. The method for making a wear and corrosion resistant petroleum pipeline as recited in claim 4 wherein: in steps (3) and (4), the temperature in the pipe does not exceed 200 ℃.

8. The method for making a wear and corrosion resistant petroleum pipeline as recited in claim 4 wherein: the thickness of the NiCrAlY layer is 50 mu m, the thickness of the first ceramic layer is 150 mu m, the thickness of the second ceramic layer is 50 mu m, and the thickness of the polytetrafluoroethylene layer is 5 mu m.

9. The method for making a wear and corrosion resistant petroleum pipeline according to any one of claims 4 to 8, wherein: the method also comprises the steps of pretreatment before preparing the bonding transition layer: spraying an acetone solution on the inner surface of the pipe body, and then carrying out sand blasting and coarsening treatment on the inner wall of the steel pipe body, wherein the surface roughness of the inner wall of the steel pipe body is 4-6 microns.

10. The method of making a wear and corrosion resistant petroleum pipeline as recited in claim 9 wherein: the sand used for sand blasting is 60-mesh white corundum, the sand blasting pressure is 0.6 MPa, and the sand blasting distance is 150 mm.

Technical Field

The invention belongs to the technical field of petroleum pipelines, and particularly relates to a wear-resistant corrosion-resistant petroleum pipeline and a preparation method thereof.

Background

Because of its excellent characteristics of good electrical conductivity, heat dissipation, high strength and easy processing, metal materials are often made into pipes and widely used in various fields, especially in oil fields. The steel tube has the advantages of easily obtained materials and mature manufacturing technology, so the cost performance is higher. However, with the continuous production of oil, CO₂The application of the oil displacement technology and the high-pressure steam oil displacement technology enables the petroleum to have corrosive media such as dissolved oxygen, carbon dioxide, sulfide, chloride ions and the like and a large amount of silt, and the original high oil content is changed into the existing high water content and high impurity content. The chemical property of the steel pipe is more active, so that the steel pipe is easily corroded by petroleum produced liquid, the hardness of the steel pipe is low, the steel pipe is easily worn, the service life of the pipe fitting is shortened, the petroleum pipeline is easily worn and corroded, even leakage is caused after perforation, and harm is brought to the public and the environment.

Therefore, along with the need of petrochemical development, the development of a new corrosion-resistant and wear-resistant petroleum pipe is urgently needed.

Disclosure of Invention

The invention aims to solve the technical problem of providing a wear-resistant corrosion-resistant petroleum pipeline and a preparation method thereof, which can improve the hardness and the hydrophobicity of the inner wall of the pipeline.

In order to solve the technical problems, the technical scheme of the invention is as follows: design a wear-resisting corrosion-resistant petroleum pipeline, including the steel pipe body, its characterized in that: the inner wall of the steel pipe body is sequentially provided with a NiCrAlY layer, a first ceramic layer, a second ceramic layer and a polytetrafluoroethylene layer from outside to inside, and the first ceramic layer and the second ceramic layer are made of Al with the grain size of 32-38 mu m₂O₃-13%TiO₂The porosity of the first ceramic layer is less than or equal to 4 percent, and the porosity of the second ceramic layer is less than or equal to 20 percent and more than or equal to 15 percent.

Preferably, the NiCrAlY layer is formed by plasma spraying of NiCrAlY particles with the particle size of 15-45 mu m.

Preferably, the thickness of the NiCrAlY layer is 50 μm, the thickness of the first ceramic layer is 150 μm, the thickness of the second ceramic layer is 50 μm, and the thickness of the polytetrafluoroethylene layer is 5 μm.

The invention also provides a method for preparing the wear-resistant corrosion-resistant petroleum pipeline, which is characterized by comprising the following steps: the method comprises the following steps:

(1) fixing a pipe body: horizontally fixing the steel pipe body on a rotary table, wherein the steel pipe body rotates at a linear speed of 0.2 m/s;

(2) preparation of a NiCrAlY layer: carrying out plasma spraying on NiCrAlY particles with the particle size of 15-45 mu m on the inner wall of the steel pipe body in the step (1) to form a NiCrAlY layer, wherein the spraying power is 40 kW, the spraying distance is 120 mm, the powder delivery rate is 20 g/min, the argon flow rate is 50L/min, and the hydrogen flow rate is 5.5L/min;

(3) preparing a first ceramic layer: plasma spraying Al with the particle size of 32-38 mu m on the NiCrAlY layer prepared in the step (2)₂O₃-13%TiO₂Granulating to obtain a first ceramic layer; the spraying power is 42 kW, the spraying distance is 120 mm, the powder feeding amount is 25 g/min, the argon flow is 50L/min, the hydrogen flow is 5.5L/min, and Al is added₂O₃-13%TiO₂The average particle diameter of the particles was 35 μm;

(4) preparing a second ceramic layer: is prepared in the step (3)The first ceramic layer is plasma sprayed with Al with the particle size of 32-38 mu m₂O₃-13%TiO₂Granulating to obtain a second ceramic layer; the spraying power is 42 kW, the spraying distance is 180 mm, the powder feeding amount is 20 g/min, the argon flow is 50L/min, the hydrogen flow is 5.5L/min, and Al is added₂O₃-13%TiO₂The average particle diameter of the particles was 35 μm;

(5) preparing a composite solution: adding a KH550 coupling agent into 60 mass percent of PTFE dispersion liquid to obtain a mixed solution, wherein the mass percent of the KH550 coupling agent in the mixed solution is 1%, then adding deionized water into the mixed solution to dilute until the mass percent of the PTFE is 20%, then stirring for 15min by ultrasonic oscillation at the stirring speed of 150-200 r/min, and then standing for half an hour to obtain a PTFE composite solution; the particle size of PTFE particles in the dispersion liquid is 170-230 nm, and the average particle size is 200 nm;

(6) preparing a polytetrafluoroethylene layer: spraying the PTFE composite solution prepared in the step (5) on the second ceramic layer prepared in the step (5) through a high-pressure spray gun to prepare a polytetrafluoroethylene layer, wherein the caliber of the spray gun is 1mm, the width of a spray width is 100mm, the spraying pressure is 0.3-0.5 MPa, and the spraying distance is 150 mm;

(7) and (3) sintering: and (4) airing the steel pipe body treated in the step (6) at room temperature for 2 hours, then carrying out blast type drying at 100 ℃ for 10 minutes, then putting the steel pipe body into a drying furnace, gradually heating the drying furnace from room temperature to 330 ℃ within 45 minutes, carrying out constant temperature sintering for 1 hour, and slowly cooling the drying furnace to room temperature to obtain the wear-resistant and corrosion-resistant petroleum pipe.

Preferably, in steps (2) to (4), the spraying is performed by a female spray gun.

Preferably, in the steps (2) to (4), after one circle of spraying, the axial moving distance of the inner hole spray gun along the steel pipe body is 10-15 mm.

Preferably, in steps (3) and (4), the temperature in the pipe does not exceed 200 ℃.

Preferably, the thickness of the NiCrAlY layer is 50 μm, the thickness of the first ceramic layer is 150 μm, the thickness of the second ceramic layer is 50 μm, and the thickness of the polytetrafluoroethylene layer is 5 μm.

Preferably, the method further comprises the step of pretreatment before preparing the bonding transition layer: spraying an acetone solution on the inner surface of the pipe body, and then carrying out sand blasting and coarsening treatment on the inner wall of the steel pipe body, wherein the surface roughness of the inner wall of the steel pipe body is 4-6 microns.

Preferably, the sand used for sand blasting is 60-mesh white corundum, the sand blasting pressure is 0.6 MPa, and the sand blasting distance is 150 mm.

Compared with the prior art, the invention has the beneficial effects that:

1. the first ceramic layer has the characteristics of high hardness and compactness, can block liquid in a pipe and improve the wear resistance and corrosion resistance of the pipeline, the second ceramic layer sintered by the first ceramic layer is looser than the first ceramic layer, the porosity is 15-20%, on one hand, the second ceramic layer has high bonding strength with the first ceramic layer, on the other hand, the bonding area with a polytetrafluoroethylene layer is increased, the bonding strength is increased, and a micro-nano binary roughness structure is formed with polytetrafluoroethylene particles, so that the micro-nano structure with the hydrophobic characteristic is easily prepared, the hydrophobicity of the inner wall of the pipe body is improved, the contact angle can reach more than 155 degrees, the adhesion and deposition of oily ester dirt are effectively reduced, and the pipe has good anti-scaling performance.

2. Because the polytetrafluoroethylene has the excellent characteristics of chemical stability, corrosion resistance, good sealing property and high lubrication, the friction coefficient between the polytetrafluoroethylene and fluid can be reduced, the fluid resistance of petroleum transportation can be reduced, secondary protection can be formed on a pipe body, and the wear resistance and corrosion resistance of the pipe are further improved.

3. The thermal expansion coefficient of the NiCrAlY layer is between that of the steel pipe and the ceramic layer, so that the thermal expansion difference between the steel pipe and the ceramic layer is relieved and reduced; the NiCrAlY alloy has high thermal fatigue resistance and good plasticity and toughness, and can absorb part of stress generated in the thermal spraying process; the NiCrAlY alloy can also form a compact film layer in a high-temperature environment, and effectively prevents oxygen and corrosive media from contacting with a pipeline substrate through the ceramic coating, so that the pipeline substrate is protected from being oxidized and corroded, and a protective barrier is added for the pipe body again.

4. Because the KH550 coupling agent is added into the PTFE dispersion liquid, the bonding between PTFE molecules can be enhanced, and the bonding strength of the PTFE coating and the second ceramic layer is enhanced.

5. The preparation process can improve the spraying quality of each layer, so that the functions of each layer can be fully exerted, and the petroleum pipe body with good wear resistance and corrosion resistance is really prepared.

6. The preparation method disclosed by the invention does not contain a volatile solvent, is green and environment-friendly, and does not harm the health of manufacturing personnel.

7. According to the invention, the steel pipe body is effectively combined with the NiCrAlY layer, the compact first ceramic layer, the loose second ceramic layer and the polytetrafluoroethylene layer together in a specific mode, so that the steel pipe body is protected layer by layer, and the service life of the petroleum pipeline is prolonged together.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a scanning electron micrograph of a cross-section of the first ceramic layer;

FIG. 3 is a scanning electron micrograph of a cross-section of a second ceramic layer;

FIG. 4 is a scanning electron micrograph of the surface of a PTFE layer.

The labels in the figure are: 1. a steel pipe body; 2. a NiCrAlY layer; 3. a first ceramic layer; 4. a second ceramic layer; 5. a polytetrafluoroethylene layer.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

The present invention defines one side near the center of the tube as the inner side and correspondingly defines the other side away from the center of the tube as the outer side.

Example one

The wear-resistant and corrosion-resistant petroleum pipeline is prepared by the following steps:

(1) pretreatment: firstly, spraying an acetone solution on the inner wall surface of the steel pipe body to remove oil stains on the inner surface; then, an inner hole sand blasting gun is adopted to carry out sand blasting and coarsening treatment on the inner wall of the steel pipe body, the sand grains are 60-mesh white corundum, the sand blasting pressure is 0.6 MPa, the sand blasting distance is 150 mm, and the sand blasting effect is better when no oxide layer or corrosion exists on the surface of the inner wall of the pipeline. The sand blasting coarsening can remove an oxide layer and corrosion on the inner surface of the steel pipe body, the bright and clean inner surface is exposed, the roughness of the sand blasting is kept, a good rough surface is provided for the coating adhesion, and the roughness of the inner surface is between 5 mu m after the sand blasting is finished;

(2) fixing a pipe body: the steel pipe body processed in the step (1) is horizontally fixed on a rotary table at once, the steel pipe body rotates at the linear speed of 0.2m/s, and the next spraying treatment is carried out, so that the inner wall of the steel pipe body is prevented from being oxidized again;

(3) preparation of a NiCrAlY layer: and preparing the NiCrAlY layer by adopting atmospheric plasma spraying equipment. Specifically, NiCrAlY particles are plasma-sprayed on the inner wall of the steel pipe body in the step (2) by using an inner hole spray gun, wherein the spraying power is 40 kW, the spraying distance is 120 mm, the powder delivery amount is 20 g/min, the argon flow is 50L/min, the hydrogen flow is 5.5L/min, the spraying thickness is 50 mu m, and the porosity is lower than 5%. And starting spraying from one end of the steel pipe body, and moving the inner hole spray gun to the other end along the axial direction of the steel pipe body by 12mm every time one circle of spraying is finished until the spraying of the inner wall of the whole pipeline is finished. In the spraying process, the steel pipe body is ventilated and cooled constantly, so that the temperature of the inner surface of the steel pipe body is not more than 200 ℃.

(4) Preparing a first ceramic layer: carrying out plasma spraying on the NiCrAlY layer prepared in the step (3) by using an inner hole spray gun to obtain Al with the particle size of 32-38 mu m and the average particle size of 35 mu m₂O₃-13%TiO₂And particles forming a first ceramic layer with a porosity of less than 4% and good particle melting. Wherein the spraying power is 42 kW, the spraying distance is 120 mm, the powder feeding amount is 25 g/min, the argon flow is 50L/min, and the hydrogen flow is 5.5L/min. And starting spraying from one end of the steel pipe body, and moving the inner hole spray gun to the other end along the axial direction of the steel pipe body for 12mm every time one circle of spraying is finished until the inner wall of the whole pipeline is sprayed once. If the thickness of one spraying is not enough, the spraying can be divided into several times until the thickness of the first ceramic layer reaches 150 μm. In the spraying process, the steel pipe body is ventilated and cooled constantly, so that the temperature of the inner surface of the steel pipe body is not more than 200 ℃.

(5) Preparing a second ceramic layer: the first ceramic layer prepared in the step (4) is sprayed with plasma by an inner hole spray gun, the particle size is 32-38 mu m, and the average particle size isAl having a particle size of 35 μm₂O₃-13%TiO₂And the grains form a second ceramic layer with porosity higher than 15% and lower than 20% and good grain melting. Wherein the spraying power is 42 kW, the spraying distance is 180 mm, the powder feeding amount is 20 g/min, the argon flow is 50L/min, and the hydrogen flow is 5.5L/min. And (3) starting spraying from one end of the steel pipe body, and moving the inner hole spray gun to the other end along the axial direction of the steel pipe body for 12mm every time one circle of spraying is finished until the inner wall of the whole pipeline is sprayed once. If the thickness of one spraying is not enough, the spraying can be divided into several times until the thickness of the first ceramic layer reaches 50 μm. In the spraying process, the steel pipe body is ventilated and cooled constantly, so that the temperature of the inner surface of the steel pipe body is not more than 200 ℃.

(6) Preparing a composite solution: adding a KH550 coupling agent into 60 mass percent of PTFE dispersion liquid to obtain a mixed solution, wherein the mass percent of the KH550 coupling agent in the mixed solution is 1%, then adding deionized water into the mixed solution to dilute until the mass percent of the PTFE is 20%, then stirring for 15min by ultrasonic oscillation at the stirring speed of 175 r/min, and then standing for half an hour to obtain a PTFE composite solution; the PTFE particles in the dispersion have a particle size of 170-230 nm and an average particle size of 200 nm.

(7) Preparing a polytetrafluoroethylene layer: and (3) spraying the PTFE composite solution prepared in the step (6) into mist by a high-pressure spray gun, and coating the mist on the second ceramic layer prepared in the step (5) to prepare a polytetrafluoroethylene layer, wherein the caliber of the spray gun is 1mm, the spray width is 100mm, the spray pressure is 0.3-0.5 MPa, and the spray distance is 150 mm. And starting spraying from one end of the steel pipe body, and moving the high-pressure spray gun to the other end along the axial direction of the steel pipe body by 12mm every time one circle of spraying is finished until the inner wall of the whole pipeline is sprayed, so that the spraying thickness reaches 5 micrometers. In the spraying process, the steel pipe body is ventilated and cooled constantly, so that the temperature of the inner surface of the steel pipe body is not more than 200 ℃.

(8) And (3) sintering: and (3) airing the steel pipe body treated in the step (7) at room temperature for 2 hours, then carrying out blast type drying at 100 ℃ for 10 minutes, then putting the steel pipe body into a drying furnace, gradually heating the drying furnace from room temperature to 330 ℃ within 45 minutes, carrying out constant temperature sintering for 1 hour, and slowly cooling the drying furnace to room temperature to obtain the wear-resistant and corrosion-resistant petroleum pipe.

Example two

The difference between the present embodiment and the first embodiment is:

in the step (1), the roughness of the inner surface is 4 μm after the sand blasting is finished;

in the steps (3) - (5) and (7), the inner hole spray gun moves 10mm to the other end along the axial direction of the steel pipe body every time one circle of spraying is finished,

in the step (6), the stirring speed is 150 r/min.

The rest is the same as the first embodiment.

EXAMPLE III

The difference between the present embodiment and the first embodiment is:

in the step (1), the roughness of the inner surface is 6 microns after the sand blasting is finished;

in the steps (3) - (5) and (7), the inner hole spray gun moves 15mm to the other end along the axial direction of the steel pipe body every time one circle of spraying is finished,

in the step (6), the stirring speed is 200 r/min.

The rest is the same as the first embodiment.

The wear-resistant and corrosion-resistant petroleum pipe shown in figure 1 is prepared by the method, and specifically, the NiCrAlY layer 2, the first ceramic layer 3, the second ceramic layer 4 and the polytetrafluoroethylene layer 5 are sequentially arranged on the inner wall of the steel pipe body 1 from outside to inside, and the first ceramic layer 3 and the second ceramic layer 4 are made of Al with the grain diameter of 32-38 mu m and the average grain diameter of 35 mu m₂O₃-13%TiO₂The porosity of the first ceramic layer 3 is less than or equal to 4 percent, and the porosity of the second ceramic layer 4 is less than or equal to 20 percent and more than or equal to 15 percent. The NiCrAlY layer 2 is formed by plasma spraying of NiCrAlY particles with the particle size of 15-45 mu m. The thickness of the NiCrAlY layer 2 is 50 μm, the thickness of the first ceramic layer 3 is 150 μm, the thickness of the second ceramic layer 4 is 50 μm and the thickness of the polytetrafluoroethylene layer 5 is 5 μm. Fig. 2 is a scanning electron microscope image of a cross section of the first ceramic layer, fig. 3 is a scanning electron microscope image of a cross section of the second ceramic layer, and fig. 4 is a scanning electron microscope image of a surface of the polytetrafluoroethylene layer. It can be seen that the first ceramic layer 3 is denser than the second ceramic layer, and the surface of the polytetrafluoroethylene layer has a uniform and regular micro-nano structure。

The wear-resistant and corrosion-resistant petroleum pipe prepared by the method is randomly sampled and then subjected to performance detection, and the number of detected samples is 1/10 and not less than 10. The hardness of the first ceramic layer is more than 850 HV0.3, the hardness of the second ceramic layer is more than 650 HV0.3, the bonding strength between the composite coating formed by the NiCrAlY layer, the first ceramic layer, the second ceramic layer and the polytetrafluoroethylene layer and the pipeline body is more than 23MPa, the static contact angle between the inner surface of the pipeline and water is more than 155 degrees, and the removed part of the inner surface of the polytetrafluoroethylene layer is not more than 5 percent through a Baige cutter test. Thereby greatly improving the wear resistance and corrosion resistance of the metal pipe body and laying a foundation for prolonging the service life of the metal pipe body.

The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.