Corrosion-resistant surfacing composite pipe flange structure

Abstract

The utility model relates to a kind of anti-corrosion surfacing composite pipe flange structure, it relates to piping connector technical field.The structure includes carbon steel flange body and pipeline body, its innovation is in that: pipeline body inner wall is compounded with corrosion-resistant alloy lining layer;Surfacing layer is surfaced with corrosion-resistant alloy on the sealing surface and the hole wall of the connected flow channel of flange body;Surfacing layer and lining layer are butted at interface, form continuous, seamless corrosion-resistant medium contact surface;Further, high-hardness wear-resistant alloy layer is cladded in the inside arc transition area of surfacing layer and other easy scouring parts.The utility model realizes the collaborative protection to corrosion and wear by the composite structure of "lining+surfacing+cladding", with the advantages of reliable structure, long life, low cost, especially suitable for conveying strong corrosion, harsh working conditions of high wear medium.

Description

Technical Field

[0001] This utility model relates to the technical field of pipe connectors, specifically to a corrosion-resistant weld overlay composite pipe flange structure. Background Technology

[0002] In industries such as chemical engineering, metallurgy, marine engineering, and flue gas treatment, pipeline systems often need to transport highly corrosive and abrasive media. As a key connecting component of pipelines, the corrosion resistance and wear resistance of the sealing surface and flow channel area of ​​flanges directly determine the safety and service life of the entire pipeline system.

[0003] In existing technologies, the main methods to improve the corrosion resistance of flanges are: firstly, using high-grade corrosion-resistant alloys for the entire flange, but this method is costly and uneconomical; secondly, using a lining structure, that is, lining the carbon steel flange with a rubber, plastic or corrosion-resistant metal layer, but the bonding strength between the lining layer and the substrate is low, making it prone to interfacial corrosion under medium penetration, and the lining layer is prone to peeling and damage under thermal stress or mechanical impact; thirdly, welding corrosion-resistant alloys onto the sealing surface, but traditional welding has a large heat input, which can easily lead to flange deformation, affecting sealing accuracy, and the composition of the weld overlay layer is easily diluted by the substrate, affecting the uniformity of corrosion resistance.

[0004] Therefore, existing corrosion-resistant flange structures suffer from defects such as insufficient reliability, short lifespan, or excessive cost, and there is an urgent need for a solution with a more reasonable structural design, more stable performance, and better economic efficiency. Utility Model Content

[0005] The purpose of this utility model is to overcome the shortcomings of the prior art and provide a corrosion-resistant weld overlay composite pipe flange structure that is compact, firmly bonded, has excellent corrosion and wear resistance, and is low in manufacturing cost.

[0006] The technical solution adopted to solve the above technical problems is: A corrosion-resistant weld overlay composite pipe flange structure includes a flange body and a pipe body. The flange body has a sealing surface, bolt holes, and an interface for connecting with the pipe body. The inner wall of the pipe body is laminated with a corrosion-resistant alloy liner. A corrosion-resistant alloy weld overlay layer is welded onto the sealing surface of the flange body and the inner wall of the flow channel connected to the sealing surface. The corrosion-resistant alloy weld overlay layer and the corrosion-resistant alloy liner layer are joined at the interface and together form a continuous corrosion-resistant medium contact surface.

[0007] As a preferred embodiment of this utility model, the mating area between the corrosion-resistant alloy weld overlay and the corrosion-resistant alloy liner is located in the middle of the inner wall of the flow channel of the flange body or on one side of the pipe body.

[0008] As a preferred embodiment of this utility model, a wear-resistant alloy layer is further clad in the inner arc transition area of ​​the corrosion-resistant alloy overlay layer and in the easily eroded area of ​​the downstream pipe inner wall.

[0009] In a preferred embodiment of this invention, the hardness of the wear-resistant alloy layer is greater than that of the corrosion-resistant alloy weld overlay layer.

[0010] As a preferred embodiment of this invention, the thickness of the corrosion-resistant alloy weld overlay is 3-8 mm.

[0011] As a preferred technical solution of this utility model, the corrosion-resistant alloy lining layer and the pipe body are mechanically or metallurgically composited, and the flange body and the pipe body are fixed by circumferential weld.

[0012] As a preferred technical solution of this utility model, the inner surface of the wear-resistant alloy layer is provided with a spirally arranged spiral protrusion facing one end of the flange body.

[0013] The beneficial effects of this utility model are as follows: 1. Dual protection: Through the combination of "corrosion-resistant alloy inner lining layer + corrosion-resistant alloy weld overlay layer", a continuous, complete and strong corrosion-resistant barrier is formed on the entire channel surface through which the medium flows, fundamentally eliminating the possibility of the medium coming into contact with the carbon steel substrate, and providing excellent corrosion resistance.

[0014] 2. Outstanding wear resistance: A high-hardness wear-resistant alloy layer is added by laser cladding in the area where the media is most severely eroded (such as the inner arc of the sealing surface), which achieves targeted reinforcement of corrosion resistance and wear resistance, and significantly improves the service life of the structure under harsh working conditions.

[0015] 3. Reliable structure and good sealing performance: The weld overlay layer and the base material are metallurgically bonded, with high bonding strength and no risk of peeling; the flange body is made of carbon steel, which has good rigidity and is not easily deformed, ensuring the long-term stability of the sealing surface and the reliability of the sealing.

[0016] 4. Excellent economic efficiency: Only expensive corrosion-resistant and wear-resistant materials are used in key functional parts, while the main structure is made of low-cost carbon steel. While ensuring excellent performance, manufacturing costs are greatly reduced, resulting in a very high cost-performance ratio.

[0017] 5. High impact resistance: The spiral protrusions attached to the inner wall of the wear-resistant alloy layer give the fluid a tangential velocity component, guiding the fluid to generate a secondary flow (spiral forward). This causes the denser solid particles in the fluid to be thrown towards the center of the channel during rotation, instead of moving close to the wall. This keeps the particles away from the wall, reduces the scouring of the inner wall by fixed particles, and improves service life. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the main cross-sectional structure of the present utility model; Figure 2 for Figure 1 A partially enlarged structural diagram; Figure 3 This is a three-dimensional structural diagram of the present invention.

[0019] In the diagram: 1. Pipe body; 2. Corrosion-resistant alloy lining; 3. Flange body; 31. Sealing surface; 32. Bolt hole; 33. Interface; 4. Corrosion-resistant alloy weld overlay; 5. Wear-resistant alloy layer; 6. Circumferential weld; 7. Spiral protrusion. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the above description of this utility model, it should be noted that the terms "one side," "the other side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] Furthermore, terms such as "identical" do not imply that components must be absolutely identical; minor differences are permissible. The term "perpendicular" simply means that the positional relationship between components is more perpendicular than "parallel," not that the structure must be perfectly perpendicular; a slight tilt is acceptable.

[0025] Example 1 exist Figures 1-3 In this invention, a technical solution is provided: a corrosion-resistant weld overlay composite pipe flange structure, mainly comprising a pipe body 1 made of carbon steel and a flange body 3, wherein the flange body 3 is welded and fixed to the pipe body 1 by a circumferential weld 6.

[0026] The inner wall of the main pipe body 1 is coated with a corrosion-resistant alloy lining layer 2. The lining layer 2 can be a mechanical composite pipe formed by drawing, hydraulic pressure or other methods with the main pipe body 1, or it can be a rolled metallurgical composite plate that is rolled and welded together.

[0027] The core improvement of this utility model lies in the treatment of the flange end. On the sealing surface 31 of the flange body 3 and the inner wall of the flow channel connected thereto, an automated welding equipment (such as strip welding) is used to weld a corrosion-resistant alloy weld overlay layer 4. The material of this weld overlay layer 4 can be selected according to the medium, such as E309L+E316L, etc. Its thickness is preferably 3-8mm to ensure sufficient corrosion resistance margin. The weld overlay layer 4 and the corrosion-resistant alloy inner lining layer 2 in the pipeline are smoothly connected in the mating area near the flange interface 33, thereby forming a seamless and continuous corrosion-resistant surface in the entire medium flow channel.

[0028] To further enhance wear resistance, a wear-resistant alloy layer 5 is clad onto the front side of the medium flow direction, namely the inner arc transition area of ​​the corrosion-resistant alloy weld overlay layer 4 and the easily eroded parts of the downstream pipeline inner wall, using laser cladding technology. This wear-resistant alloy layer 5 can be made of cobalt-based or nickel-based tungsten carbide material, with a hardness of HRC 55 or higher, which can effectively resist the erosion and wear of solid particles.

[0029] The advantage of this utility model over traditional lined flanges is that traditional structures have seams and dead zones between the lining and the flange base, which can easily lead to media penetration and corrosion. In contrast, this utility model is an all-metal, integrated, continuous protective layer, which greatly improves reliability. Secondly, to further improve the erosion resistance of the internal structure, spiral protrusions 7 are set on the inner wall surface of the wear-resistant alloy layer 5. The two ends of the spiral protrusions 7 are corresponding to the two ends of the wear-resistant alloy layer 5, so that the denser solid particles in the fluid will be thrown towards the center of the channel during rotation, instead of moving close to the wall. This keeps the particles away from the wall, reduces the erosion of the inner wall by fixed particles, and improves the service life.

[0030] The specific operating principle of this corrosion-resistant weld overlay composite pipe flange structure is as follows: When conveying corrosive or solid particle-containing media, this structure achieves long-term stable operation through multiple protection mechanisms. When the medium flows through the main pipe 1, it first comes into contact with the corrosion-resistant alloy inner lining layer 2 composite on the inner wall of the pipe. This layer, as the first line of defense, effectively resists the chemical corrosion of the medium. As the medium continues to flow towards the flange connection area, it passes through the continuous corrosion-resistant medium contact surface formed by the butt joint of the corrosion-resistant alloy weld overlay layer 4 and the corrosion-resistant alloy inner lining layer 2 at the interface 33. This seamless joint structure completely eliminates the corrosion. In addition to the joint defects of traditional lining structures, preventing interface corrosion caused by media penetration, when the media flows through the sealing surface 31 of the flange body 3 and the inner wall of the connected flow channel, the corrosion-resistant alloy overlay layer 4 provides the same excellent corrosion resistance as the pipe lining layer 2, ensuring that the entire flow channel has consistent anti-corrosion capability. For media containing solid particles, the wear-resistant alloy layer 5, which is set in the arc transition area inside the corrosion-resistant alloy overlay layer 4 and the easily eroded area of ​​the downstream pipe inner wall, begins to play a key role. Its hardness is significantly higher than that of the overlay layer 4, and it can effectively resist the direct erosion and wear of particles. To further enhance erosion resistance, spiral protrusions 7 are provided on the inner surface of the wear-resistant alloy layer 5. When fluid passes through, these spiral protrusions 7 guide the medium to generate a rotating flow, forming a controllable secondary flow. The centrifugal effect generated by this spiral flow throws denser solid particles in the fluid toward the central area of ​​the flow channel, achieving solid-liquid separation and keeping abrasive particles away from the inner wall surface of the pipe and flange, reducing the direct erosion intensity at the source. At the same time, this flow field optimization can also reconstruct the boundary layer in the near-wall region, suppressing the generation of local eddies and cavitation. In the entire structure, the pipe body 1 and the flange body 3 are firmly connected by a circumferential weld 6, ensuring the overall strength and sealing of the structure. This composite protection design enables the flange structure to maintain long-term stable sealing performance and service life under harsh conditions of coexisting corrosion and wear, while achieving cost optimization through reasonable material configuration.

[0031] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A corrosion-resistant weld overlay composite pipe flange structure, comprising a flange body (3) and a pipe body (1), wherein the flange body (3) has a sealing surface (31), bolt holes (32) and an interface (33) for connecting with the pipe body (1), characterized in that: The inner wall of the pipe body (1) is coated with a corrosion-resistant alloy lining layer (2). The sealing surface (31) of the flange body (3) and the inner wall of the flow channel connected to the sealing surface (31) are welded together with a corrosion-resistant alloy weld overlay layer (4). The corrosion-resistant alloy weld overlay layer (4) and the corrosion-resistant alloy lining layer (2) are joined at the interface (33) and together form a continuous corrosion-resistant medium contact surface.

2. The corrosion-resistant weld overlay composite pipe flange structure according to claim 1, characterized in that: The mating area between the corrosion-resistant alloy weld overlay (4) and the corrosion-resistant alloy inner lining (2) is located in the middle of the inner wall of the flow channel of the flange body (3) or on one side of the pipe body (1).

3. A corrosion-resistant weld overlay composite pipe flange structure according to claim 1 or 2, characterized in that: In the inner arc transition area of ​​the corrosion-resistant alloy overlay layer (4) and the downstream pipe inner wall area prone to erosion, a wear-resistant alloy layer (5) is also fused and formed.

4. The corrosion-resistant weld overlay composite pipe flange structure according to claim 3, characterized in that: The hardness of the wear-resistant alloy layer (5) is greater than that of the corrosion-resistant alloy overlay layer (4).

5. The corrosion-resistant weld overlay composite pipe flange structure according to claim 1, characterized in that: The thickness of the corrosion-resistant alloy overlay (4) is 3-8 mm.

6. The corrosion-resistant weld overlay composite pipe flange structure according to claim 1, characterized in that: The corrosion-resistant alloy lining (2) and the pipe body (1) are mechanically or metallurgically composited, and the flange body (3) and the pipe body (1) are welded and fixed by a circumferential weld (6).

7. The corrosion-resistant weld overlay composite pipe flange structure according to claim 3, characterized in that: The inner surface of the wear-resistant alloy layer (5) is provided with spiral protrusions (7) arranged spirally towards one end of the flange body (3).

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