阅读说明：本技术 一种海底用管道防腐的方法 (Method for preventing corrosion of submarine pipeline ) 是由 李鹏 屠金 魏继春 邱航 李炜 李国青 孟扬 于本河 于 2020-08-04 设计创作，主要内容包括：本发明属于管道防腐技术领域,具体公开了一种海底用管道防腐的方法,它包括以下防腐步骤：(1)除锈、除污；(2)第一遍喷涂；(3)第二遍喷涂；(4)防腐加强,利用强耐腐蚀性、强渗透性、强附着力的TK-7氟硅防腐涂料及其复合材料TK-7氟硅碳纤维缠绕带对管道进行喷涂及缠绕,防腐方法简单,使得管道中抗冲击、硬度性能优良,附着力极佳、抗弯曲以及耐绝缘电阻达到防腐技术规范标准,使得管道使用寿命延长。(The invention belongs to the technical field of pipeline corrosion prevention, and particularly discloses a method for preventing corrosion of a pipeline for a seabed, which comprises the following corrosion prevention steps: (1) derusting and decontaminating; (2) spraying for the first time; (3) spraying for the second time; (4) the corrosion resistance is enhanced, the TK-7 fluorine silicon anti-corrosion coating with strong corrosion resistance, strong permeability and strong adhesive force and the TK-7 fluorine silicon carbon fiber winding belt made of the composite material are used for spraying and winding the pipeline, the corrosion resistance method is simple, so that the pipeline is excellent in impact resistance and hardness performance, excellent in adhesive force, bending resistance and insulation resistance, and capable of reaching the corrosion resistance technical specification standard, and the service life of the pipeline is prolonged.)

1. A method for preventing corrosion of pipelines used on the seabed is characterized by comprising the following corrosion prevention steps:

(1) rust removal and dirt removal: removing oil, grease and dust pollutants which affect the surface treatment or the adhesion of the anticorrosive coating and the steel pipe, removing weld beading, burrs and edges and corners on the surface of the steel pipe, and removing rust by using a rust removing tool, wherein the rust removing grade reaches St2 or Sa 2;

(2) spraying for the first time: TK-7 fluorine-silicon anticorrosive paint is sprayed and permeates into an anticorrosive material to form a uniform and leak-free compact oxide layer.

(3) And (3) second spraying: and spraying TK-7 fluorine-silicon anticorrosive paint after the interval of 10-15 minutes is carried out on the same position of the pipeline.

(4) And (3) corrosion prevention and reinforcement: and (4) winding the pipeline by adopting a TK-7 fluorine silicon carbon fiber winding belt after the step (3), wherein the lapping width is one half of the lapping width during winding, the forward winding and the reverse winding are respectively carried out once, and the pipeline is transported and used after 24 hours.

2. The method of corrosion protection of subsea pipelines according to claim 1, wherein: the TK-7 fluorine-silicon anticorrosive paint is resin and polyurethane, and zinc phosphate is added compositely.

3. The method of corrosion protection of subsea pipelines according to claim 1, wherein: the spraying temperature in the step (2) and the step (3) is-30-50 ℃, and the humidity is less than or equal to 85%.

4. The method of corrosion protection of subsea pipelines according to claim 1, wherein: the thickness of the oxide layer in the step (2) is 20-30 μm.

5. The method of corrosion protection of subsea pipelines according to claim 1, wherein: in the step (3), the thickness is 40-50 μm.

6. The method of corrosion protection of subsea pipelines according to claim 1, wherein: the corrosion prevention step is suitable for corrosion prevention of the pipeline main body and corrosion prevention of the repaired mouth weld joint.

Technical Field

The invention belongs to the technical field of anticorrosive coatings and anticorrosive pipelines, and particularly relates to a method for preventing corrosion of a pipeline for seabed.

Background

The corrosion prevention of pipelines is a protection technology for preventing the pipelines from being corroded by soil, air and transport media (petroleum, natural gas and the like). Pipelines for conveying oil and gas are mostly in a complex soil environment, and conveyed media are also corrosive, so that the inner wall and the outer wall of the pipeline can be corroded. Once the pipeline is corroded and perforated, oil and gas are lost, which not only interrupts transportation, but also pollutes the environment and even can cause fire hazard and causes harm. Therefore, the prevention of corrosion of pipelines is an important part of pipeline engineering.

The pipeline corrosion prevention is generally carried out by base surface treatment, paint blending, intermediate paint brushing, brushing or spraying construction and maintenance treatment, the pipeline corrosion prevention is divided into main body corrosion prevention and repaired mouth welding port corrosion prevention, common corrosion prevention layer materials comprise petroleum asphalt, epoxy coal asphalt, adhesive tapes, powder epoxy and PE heat-shrinkable materials, the main body of the pipeline mainly adopts a three-layer PE composite structure, and the three-layer PE heat-shrinkable repaired mouth material is preferred.

The existing pipeline anticorrosive coating is weak in adhesive force and corrosion resistance, and the existing pipeline anticorrosive coating is afraid of colliding in the transportation construction process, and after a leakage point appears, the pipeline is extremely easy to corrode in seawater.

Disclosure of Invention

In order to overcome the defects of the prior art, the TK-7 fluorine-silicon anticorrosive paint with strong corrosion resistance, strong permeability and strong adhesive force and the TK-7 fluorine-silicon carbon fiber winding belt made of the composite material are used for spraying and winding the pipeline, and the method for preventing the pipeline from being corroded at the sea bottom is provided.

The invention provides a method for preventing corrosion of a pipeline for a seabed, which comprises the following corrosion prevention steps:

(1) rust removal and dirt removal: removing oil, grease and dust pollutants which affect the surface treatment or the adhesion of the anticorrosive coating and the steel pipe, removing weld beading, burrs and edges and corners on the surface of the steel pipe, and removing rust by using a rust removing tool, wherein the rust removing grade reaches St2 or Sa 2;

(2) spraying for the first time: TK-7 fluorine-silicon anticorrosive paint is sprayed and permeates into an anticorrosive material to form a uniform and leak-free compact oxide layer.

(3) And (3) second spraying: and spraying TK-7 fluorine-silicon anticorrosive paint after the interval of 10-15 minutes is carried out on the same position of the pipeline.

(4) And (3) corrosion prevention and reinforcement: and (4) winding the pipeline by adopting a TK-7 fluorine silicon carbon fiber winding belt after the step (3), wherein the lapping width is one half of the lapping width during winding, the forward winding and the reverse winding are respectively carried out once, and the pipeline is transported and used after 24 hours.

Compared with the prior art, the invention has the advantages and the technical effects that: the TK-7 fluorosilicone anticorrosive paint with strong corrosion resistance, strong permeability and strong adhesive force is used for three layers of anticorrosive treatment of different types, the anticorrosive method is simple, so that the pipeline is excellent in impact resistance and hardness performance, excellent in adhesive force, bending resistance and insulation resistance, and can reach the standard of anticorrosive technical specifications, the service life of the pipeline is prolonged, and the service life can reach 30 years.

Drawings

FIG. 1 is a cross-sectional view of the subsea pipeline corrosion protection of the present invention.

1. Steel pipe, 2, dope layer, 3, fluorine silicon carbon fiber winding area.

Detailed Description

The technical solution of the present invention is further described in detail with reference to the accompanying drawings and specific embodiments.

Aiming at the reinforced anticorrosion technology of the steel pipeline for the seabed, the TK-7 fluorine silicon anticorrosive paint with strong corrosion resistance, strong permeability and strong adhesive force and the TK-7 fluorine silicon carbon fiber winding belt made of the composite material are used for spraying and winding the pipeline. The TK-7 fluorine-silicon carbon fiber winding belt has the same elastic modulus as carbon steel, is high in tensile strength, 11-15 times of the strength of a steel pipe, and has good deformation cooperativity with the steel pipe. The TK-7 fluorine-silicon carbon fiber winding belt is prepared by dipping composite carbon fibers in TK-7 fluorine-silicon anticorrosive paint, and the concrete performance test of the TK-7 fluorine-silicon carbon fiber winding belt is as follows:

remarking: stretching speed: 2mm/min, theoretical thickness: 0.111 mm.

The concrete steps of performing pipeline corrosion prevention by using the TK-7 fluorine silicon anticorrosive paint and the TK-7 fluorine silicon carbon fiber winding belt are as follows:

prefabricated pipeline

Derusting and decontamination treatment before corrosion prevention, wherein before derusting, pollutants such as oil, grease, dust and the like which affect the surface treatment or the adhesion of an anticorrosive coating and a steel pipe are removed, and the treatment is carried out according to the regulation of steel surface treatment specification before coating SY/T0407; removing the defects of welding beading, burrs, edges and corners and the like on the surface of the steel pipe; and the rust removal by using a tool or sand blasting is adopted, and the rust removal grade reaches St2 or Sa 2.

1. Spraying for the first time: spraying is carried out within 4 hours after rust removal, and if re-embroidering occurs, rust removal needs to be carried out again. The spraying temperature is-10-50 ℃, and the humidity of the construction environment is below 85%. The preparation method is characterized in that a TK-7 fluorine-silicon anticorrosive coating base material with strong permeability is adopted, the coating is mainly made of resin and polyurethane, zinc phosphate with the mass fraction of 5% -10% is added in a compounding manner, and the zinc phosphate has two crystal water which can react with-OH and-COOH groups to generate gel. When the hydroxyl and carboxyl of the resin used by the coating react with phosphate, the bonding force of the inner layer is enhanced, and the zinc phosphate can oxidize rust, so that the adhesive force is effectively improved, and meanwhile, the influence of a little rust on the adhesive force of the anticorrosive layer is avoided. Spraying 20-30 μm for the first time, penetrating into the anticorrosive material to form a compact oxide layer, and observing to ensure uniform spraying.

In addition, the ammonium salt has strong corrosion action on metal, and the zinc phosphate can inhibit the penetration and diffusion action of ammonium ions on a coating. The metal surface is "phosphated" and kept passive. Phosphate can inhibit corrosion of ammonium ions to metals. The zinc ions form cathode protection on the surface of the steel and prevent the further corrosion of the metal. Only soluble phosphates will form ferrous ion reactions in the cathodic area of the metal surface or, after hydrolysis, will form heteropoly acid complexes with the rust to form tough paint films, thereby stabilizing the rust.

2. And (3) second spraying: the TK-7 fluorosilicone anticorrosive paint is sprayed on the first layer 10 minutes later (at the same position at intervals), so that the thickness of the paint reaches 40-50 mu m and omission is avoided.

3. And (3) strengthening antiseptic treatment: after the last step is finished, the TK-7 fluorine silicon carbon fiber winding belt is immediately adopted to wind the pipeline, the lapping width is one half, the lapping tightness can be guaranteed due to the fact that the lapping width is one half when the pipeline is wound, the pipeline is wound in the forward direction and the reverse direction, the thickness and the strength of an anti-corrosion layer can be enhanced due to the fact that the lapping width is one half, the pipeline is naturally dried, and the pipeline can be transported and used after 24 hours.

The schematic diagram of the cross-sectional structure of the pipeline port is shown in fig. 1, and the structure of the pipeline port is from inside to outside: the steel pipe-first spraying-second spraying-fluorine silicon carbon fiber winding belt is characterized in that the structure of the pipeline after corrosion prevention comprises a steel pipe layer 1, a coating layer 2 and a fluorine silicon carbon fiber winding belt 3.

The corrosion resistance indexes of the pipeline main body are as follows:

second, on-site joint coating construction

After the pipeline is welded, the defects of welding beading, burrs, edges and corners and the like on the surface of the steel pipe and oil stains and the like influencing the binding power are removed, and the rust removal grade reaches St2 or Sa 2. The reinforced anticorrosive layer of the prefabricated pipeline is roughened within the range of 20-30cm respectively, so that the adhesive force can be effectively enhanced.

Spraying a TK-7 fluorosilicone anticorrosive paint base material with strong permeability, adding zinc phosphate compositely, spraying 20-30 μm for the first time, penetrating into an anticorrosive material to form a compact oxide layer, and adopting an observation method to ensure uniform spraying and no omission.

TK-7 fluorosilicone anticorrosive paint is sprayed 10 minutes after the first spraying (at the same position at intervals), so that the thickness is 40-50 mu m and omission is avoided.

And after the last step is finished, immediately winding the pipeline by adopting the TK-7 fluorine silicon carbon fiber winding belt doped with the curing agent, wherein the lapping width is one half of the width during winding, the forward winding and the reverse winding are respectively performed once, and the construction can be continued after 30 minutes.

The performance indexes of the fluorine-silicon-based joint coating anticorrosive layer are as follows:

the above description is only an example of the present invention, and is not intended to limit the present invention in any way, and those skilled in the art can make many variations and modifications of the present invention without departing from the scope of the present invention by using the method disclosed above, and the present invention is covered by the claims.