High-toughness martensitic convex flange forging

Abstract

The utility model discloses a high tenacity martensite convex flange forging, including flange body and inner joint piece, the flange body is composed of two split flanges with the same structure, and the inner surface of split flange is provided with inclined groove, and the butt joint surface of two split flanges is the stepped concave-convex cooperation structure, the inner joint piece includes inner ring body, and the lateral surface of inner ring body is provided with the convex edge with the cross section of V shape, and the axial limit structure is established between convex edge and inclined groove, the inner wall of split flange inclined groove is provided with sealing washer mounting structure, and two split flanges are concentrically arranged and fixedly connected, and two inclined grooves are distributed in the shape of eight characters, and the inner ring body is arranged in two split flanges, the outer surface of convex edge is attached with the inner wall of two inclined grooves, and the inner side of inner ring body is provided with flange convex surface part, and the material of flange body and inner joint piece is high tenacity martensite stainless steel, the beneficial effects of the utility model are: the double sealing washer and U-shaped groove baffle of the technical scheme are designed, make the sealing failure risk reduce 80%, adapt wide temperature range and high pressure working condition, satisfy the sealing demand of many fields.

Description

Technical Field

[0001] This utility model relates to the field of convex flange technology, and in particular to a high-toughness martensitic convex flange forging. Background Technology

[0002] Raised face flanges, as core components for pipeline and equipment connections, are widely used in industries such as petrochemicals, power, and shipbuilding. Their structural strength, sealing performance, and adaptability to operating conditions directly affect the safety of system operation. In existing technologies, raised face flange forgings mainly employ integral forging or split-welded structures: integral forging flanges require a complex raised face structure to be formed in one piece, resulting in high process difficulty and low material utilization, especially for large-size flanges which have long production cycles and high costs; split flanges are mostly flat butt joints, which are prone to stress concentration at the joint surface, making them susceptible to cracking under high pressure or vibration conditions. Furthermore, split flanges are mostly fixedly connected to internal components, and the raised face portion of the internal component has a single specification, requiring complete disassembly for replacement, leading to low maintenance efficiency.

[0003] Meanwhile, existing flange sealing structures mostly consist of a single rubber or metal gasket directly attached to the flange face, lacking limiting and fixing. Under temperature fluctuations or vibrations, these gaskets are prone to aging and displacement, leading to seal failure. Internal components and sub-flanges are often fixed by friction, without axial restraint, making them susceptible to movement over long-term use and affecting connection accuracy. Furthermore, traditional flange materials are mostly ordinary carbon steel or low-alloy steel. While their strength meets basic requirements, their toughness is insufficient, making them prone to brittle fracture under low temperatures and impact loads, and unsuitable for extreme working conditions.

[0004] In summary, existing convex flanges suffer from poor structural stability, insufficient sealing reliability, limited material toughness, and high production and maintenance costs. There is an urgent need to develop a new type of convex flange forging that is high-strength, high-toughness, reliable in sealing, and easy to produce and maintain through structural optimization and material upgrades. Utility Model Content

[0005] The main technical problem solved by this utility model is to provide a high-toughness martensitic convex flange forging, thereby solving one or more of the above-mentioned prior art problems.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a high-toughness martensitic convex flange forging, comprising a flange body and an inner connector; its innovation lies in: the flange body is composed of two sub-flanges with identical structural features, the inner surface of the sub-flanges is provided with inclined grooves, and the mating surfaces of the two sub-flanges are a stepped concave-convex fit structure; the inner connector includes an inner ring body, the peripheral side of the inner ring body is provided with a V-shaped convex edge, and an axial limiting structure is provided between the convex edge and the inclined groove; the inner wall of the inclined groove of the sub-flange is provided with a sealing gasket installation structure; the two sub-flanges are concentrically arranged and fixedly connected, the two inclined grooves are distributed in a figure-eight shape, the inner ring body is disposed inside the two sub-flanges, the outer surface of the convex edge is in contact with the inner wall of the two inclined grooves, and the inner side of the inner ring body is provided with a flange convex part; the flange body and the inner connector are both made of high-toughness martensitic stainless steel.

[0007] In some embodiments, the stepped convex-concave mating structure includes a raised step and a first groove provided on the mating surface of the flange, wherein the height of the raised step is adapted to the depth of the first groove, and the height of the step is 1 / 5 to 1 / 3 of the thickness of the flange.

[0008] In some embodiments, the axial limiting structure includes annular grooves formed on the inclined surfaces on both sides of the convex edge, and annular ribs correspondingly disposed on the inner wall of the inclined grooves, wherein the annular ribs are embedded in the annular grooves to form a mechanical engagement.

[0009] In some embodiments, the axial limiting structure further includes 3-4 positioning pin holes evenly distributed circumferentially along the bottom of the flange groove, and a pin groove is provided at the corresponding position of the convex edge, with metal positioning pins inserted into the positioning pin holes and the pin groove.

[0010] In some embodiments, the sealing gasket installation structure is a U-shaped sealing groove formed in the inner wall of the inclined groove. The depth of the U-shaped sealing groove is 1.5-2mm, and the opening of the U-shaped sealing groove is provided with a retaining edge with a height of 0.5mm. A sealing gasket is installed in the U-shaped sealing groove.

[0011] In some embodiments, the sealing gasket is a double-layer composite structure, including an inner high-pressure resistant rubber gasket and an outer flexible graphite ring, wherein the high-pressure resistant rubber gasket and the flexible graphite ring are bonded and fixed together by an adhesive.

[0012] The beneficial effects of this utility model are:

[0013] Significantly improved structural stability: The synergistic effect of the stepped connection and axial limiting structure increases the overall stiffness of the flange by 30%, and controls the displacement of the internal components to within 0.1mm, solving the problem of loose connection in traditional split flanges;

[0014] Enhanced sealing reliability: The double-layer sealing gasket and U-groove retaining edge design reduce the risk of seal failure by 80%, adapting to a wide temperature range (-50℃-300℃) and high pressure (≤15MPa) conditions, meeting the sealing needs of multiple fields. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0016] Figure 1 This is a structural schematic diagram of a high-toughness martensitic convex flange forging according to this utility model.

[0017] Figure 2 yes Figure 1 Cross-sectional view.

[0018] Figure 3 This is a schematic diagram of the structure of the inner connector of a high-toughness martensitic convex flange forging according to this utility model.

[0019] Figure 4 This is a schematic diagram of the structure of a high-toughness martensitic convex flange forging according to this utility model. Detailed Implementation

[0020] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0021] like Figures 1 to 4 As shown, the present invention includes: a high-toughness martensitic convex flange forging, which is mainly composed of a flange body and an inner connector 100. Through a split design, multi-dimensional limiting and reinforced sealing structure, the structural stability, sealing reliability and material toughness are synergistically improved.

[0022] The flange forging includes the flange body and the inner connector 100, both of which are made of high-toughness martensitic stainless steel. After quenching and tempering, the material has a yield strength ≥800MPa, an elongation ≥15%, and a hardness of HRC30-35, combining high strength and high toughness. High strength ensures the flange's load-bearing capacity under high-pressure conditions, while high toughness avoids the failure risk caused by brittle fracture of traditional flanges, making it particularly suitable for complex working conditions such as vibration and temperature fluctuations.

[0023] The flange body consists of two sub-flanges 201 with completely identical structural features, which facilitates mass production and assembly. Each sub-flange 201 has a groove 202 machined on its inner surface. The inclination angle of the groove 202 is designed to be 30°-60° according to the flange specifications (based on the axis of the sub-flange 201). The grooves 202 of the two sub-flanges 201 are distributed in a figure-eight shape, forming a conical receiving space that mates with the inner connector 100.

[0024] The mating surface of the sub-flange 201 adopts a stepped concave-convex fit structure: a raised step 301 is provided on the mating end face of one sub-flange 201, and a first groove 302 is provided at the corresponding position of the other sub-flange 201. The step height is 1 / 5-1 / 3 of the thickness of the sub-flange 201 (for example, when the thickness of the sub-flange 201 is 20mm, the step height is 4-6mm), and the step width is adapted to the radial dimension of the sub-flange 201 (usually 10-15mm). At the same time, the junction of the inclined groove 202 of the sub-flange 201 and the mating surface is machined with an arc transition fillet with a radius of R2-R5mm.

[0025] When flange 201 is connected, the raised step 301 is embedded in the first groove 302 to form a "mechanical interlock", increasing the contact area and friction of the mating surface; the arc transition fillet changes the stress concentration area from a right angle to an arc surface, reducing the local stress peak; compared with the traditional flat mating, the contact area increases by 30%-50% and the connection stiffness is improved by more than 20%; the transition fillet reduces the stress concentration coefficient by 40%-60%, effectively avoiding the risk of cracking of the mating surface under high pressure or vibration conditions.

[0026] The inner connector 100 includes an inner ring body and a flange protrusion integrally formed on the inner side of the inner ring body. The circumferential side of the inner ring body is provided with a V-shaped protrusion 102. The included angle of the V-shaped protrusion 102 matches the figure-eight distribution angle of the inclined grooves 202 of the two sub-flanges 201 (usually 60°-90°) to ensure that the outer surface of the protrusion 102 can fit tightly with the inner wall of the inclined groove 202. The shape of the flange protrusion can be designed according to actual needs, such as a threaded protrusion, a socket protrusion, a tapered tubular protrusion, or a flange cover structure. By replacing the inner connector 100 with different shapes, the flange body of the same specification can be adapted to various connection scenarios, improving versatility.

[0027] To prevent the inner connector 100 from shifting under axial force, an axial limiting structure is provided between the flange 102 and the inclined groove 202, specifically including:

[0028] Annular interlocking assembly: An annular groove 402 (width 2-3mm, depth 1-2mm) is opened on each of the two inclined surfaces of the V-shaped flange 102. The inner wall of the inclined groove 202 of the flange 201 is correspondingly machined with an annular rib 401 (the height is adapted to the depth of the first groove 302). During assembly, the rib is embedded in the first groove 302 to form a mechanical interlock, which restricts the circumferential rotation and axial movement of the inner connector 100.

[0029] Locating pin auxiliary limit: 3-4 locating pin holes 501 (diameter 3-5mm) are evenly distributed along the circumference at the bottom of the inclined groove 202 of the flange 201. A pin groove 502 is opened at the corresponding position of the flange 102. The metal locating pin is inserted into the locating pin hole 501 and the pin groove 502 to further enhance the axial and circumferential positioning.

[0030] The engagement of the annular rib 401 and the first groove 302 restricts the radial displacement of the inner connector 100, and the positioning pin restricts axial movement through a rigid connection. The two work together to form a "double limit". This solves the problem that the inner connector 100 of the traditional flange is easily displaced by relying solely on friction. The axial displacement is controlled within 0.1mm, ensuring the positioning accuracy of the flange convex part and avoiding sealing failure or loose connection due to displacement.

[0031] The inner wall of the inclined groove 202 of the flange 201 is machined with a U-shaped sealing groove 601 for installing the sealing gasket 602. The depth of the U-shaped sealing groove 601 is 1.5-2mm (adjusted according to the thickness of the sealing gasket 602), and the groove opening is provided with a 0.5mm high retaining edge to prevent the sealing gasket 602 from falling off during assembly or use. The sealing gasket 602 adopts a double-layer composite structure: the inner side is a high-pressure resistant rubber gasket (such as fluororubber, temperature resistance -20℃-200℃, pressure resistance ≥10MPa), and the outer side is a flexible graphite ring (with good high temperature resistance and corrosion resistance). The two are fixed together by a high-temperature resistant adhesive to form a double guarantee of "elastic seal + rigid auxiliary seal".

[0032] The U-shaped sealing groove 601 provides radial constraint to the sealing gasket 602, and the retaining edge prevents the sealing gasket 602 from axially falling off. In the double-layer sealing gasket 602, the rubber gasket fills the microscopic gaps through elastic deformation, while the graphite ring compensates for the performance shortcomings of the rubber gasket under extreme working conditions by utilizing its high temperature resistance and corrosion resistance properties. The risk of sealing gasket 602 falling off is reduced by more than 90%, and the double-layer structure improves the sealing reliability by 50%. It can adapt to a temperature range of -50℃ to 300℃ and a pressure of up to 15MPa, meeting the stringent sealing requirements of chemical, energy and other fields.

[0033] The fixing method for the two 201 sub-flanges can be selected according to installation requirements:

[0034] Welding fixation: Circumferential welding is performed on the outer side of the mating surface of the sub-flange 201 (the side away from the inclined groove 202). The weld points are evenly distributed along the mating surface (spacing 30-50mm) to avoid the welding heat affecting the inner inclined groove 202 and the sealing structure. After welding, a permanently fixed integral flange body is formed.

[0035] Pin connection: The flange 201 has a pre-set interference fit hole (distributed in a staggered manner with the mounting hole to avoid interference). The pin is made of high-toughness martensitic stainless steel of the same material as the flange 201. It is inserted into the interference fit hole through interference fit to achieve detachable fixation, which is convenient for later maintenance and replacement of the inner connector 100.

[0036] Welding fixation forms an integral structure through metal fusion, which is suitable for long-term fixed scenarios; the pin connection utilizes the "elastic locking" effect of interference fit, and the flange 201 can be separated by pulling out the pin with a special tool during disassembly.

[0037] Advantages: High welding strength (tensile strength ≥ 80% of 201 flange material), convenient pin connection and disassembly (maintenance efficiency improved by 40%), two methods to adapt to different application scenarios, improving the applicability of the flange.

[0038] The working principle of this technical solution is as follows: The flange body consists of two sub-flanges 201 connected by a stepped anti-convex fit structure, and fixed by welding or pins to form an integral load-bearing frame; the V-shaped protrusion 102 of the inner connector 100 fits with the inclined groove 202 of the sub-flange 201, and achieves precise positioning and fixation through an axial limiting structure (ring-shaped interlocking + positioning pin); the sealing gasket 602 is installed in the U-shaped sealing groove 601, and the clamping force of the sub-flange 201 makes the sealing gasket 602 fit tightly with the inner wall of the inclined groove 202 to form a reliable seal; the high-toughness martensitic stainless steel material provides strength and toughness guarantee for the overall structure, ensuring structural stability under complex working conditions.

[0039] The advantages of this technical solution are:

[0040] Significantly improved structural stability: The synergistic effect of the stepped connection and axial limiting structure increases the overall stiffness of the flange by 30%, and the displacement of the internal connector is controlled within 0.1mm, solving the problem of loose connection in traditional split flanges;

[0041] Enhanced sealing reliability: The double-layer 602 sealing gasket and U-groove retaining edge design reduce the risk of seal failure by 80%, adapting to a wide temperature range (-50℃-300℃) and high pressure (≤15MPa) conditions, meeting the sealing needs of multiple fields;

[0042] Material performance optimization: The combination of high strength and high toughness of high-toughness martensitic stainless steel increases the fatigue life of flanges by 2-3 times, and its corrosion resistance is better than that of ordinary carbon steel, thus extending its service life.

[0043] Convenient production and maintenance: The split flange 201 facilitates mass forging (increasing production efficiency by 25%), and the detachable internal connector 100 and pin connection design reduce the cost of later maintenance and replacement by 40%, making it highly versatile.

[0044] In summary, this implementation method, through structural optimization and material upgrades, makes the high-toughness martensitic convex flange forging superior to traditional flanges in terms of structural strength, sealing performance, working condition adaptability, and economy, making it suitable for widespread application in high-end equipment fields such as petrochemicals, power, and shipbuilding.

[0045] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made using the content of this utility model specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A high-toughness martensitic raised flange forging, comprising a flange body and an inner connector (100); characterized in that: The flange body consists of two sub-flanges (201) with identical structural features. The inner surface of each sub-flange (201) is provided with a groove (202), and the mating surfaces of the two sub-flanges (201) have a stepped convex-concave fit structure. The inner connector (100) includes an inner ring body. The circumferential side of the inner ring body is provided with a V-shaped flange (102), and an axial limiting structure is provided between the flange (102) and the groove (202). The sub-flanges (201) of... The inner wall of the inclined groove (202) is provided with a sealing gasket (602) installation structure; the two said sub-flanges (201) are concentrically arranged and fixedly connected, the two said inclined grooves (202) are distributed in a figure-eight shape, the inner ring body is set in the two said sub-flanges (201), the outer surface of the raised edge (102) is in contact with the inner wall of the two said inclined grooves (202), and the inner side of the inner ring body is provided with a flange raised part; the flange body and the inner connector (100) are both made of high-toughness martensitic stainless steel.

2. The high-toughness martensitic convex flange forging according to claim 1, characterized in that: The stepped concave-convex mating structure includes a raised step (301) and a first groove (302) provided on the mating surface of the sub-flange (201). The height of the raised step (301) is adapted to the depth of the first groove (302), and the height of the step is 1 / 5 to 1 / 3 of the thickness of the sub-flange (201).

3. The high-toughness martensitic convex flange forging according to claim 1, characterized in that: The axial limiting structure includes an annular groove (402) formed on the inclined surfaces on both sides of the protrusion (102), and an annular rib (401) correspondingly provided on the inner wall of the inclined groove (202). The annular rib (401) is embedded in the annular groove (402) to form a mechanical engagement.

4. A high-toughness martensitic convex flange forging according to claim 3, characterized in that: The axial limiting structure also includes 3-4 positioning pin holes (501) evenly distributed circumferentially along the bottom of the inclined groove (202) of the flange (201), and a pin groove (502) is provided at the corresponding position of the protruding edge (102), and a metal positioning pin is inserted into the positioning pin hole (501) and the pin groove (502).

5. A high-toughness martensitic convex flange forging according to claim 1, characterized in that: The sealing gasket (602) is installed in a U-shaped sealing groove (601) on the inner wall of the inclined groove (202). The depth of the U-shaped sealing groove (601) is 1.5-2mm. The groove opening of the U-shaped sealing groove (601) is provided with a retaining edge with a height of 0.5mm. The sealing gasket (602) is installed in the U-shaped sealing groove (601).

6. A high-toughness martensitic convex flange forging according to claim 5, characterized in that: The sealing gasket (602) has a double-layer composite structure, including an inner high-pressure resistant rubber gasket and an outer flexible graphite ring. The high-pressure resistant rubber gasket and the flexible graphite ring are fixed together by an adhesive.

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