A high-pressure flange sealing surface laser cladding annular follow-up protection tool, system and cladding repair method

Abstract

The application discloses a kind of annular follow-up protection toolings, systems and cladding repair methods for high-pressure flange sealing surface laser cladding.The tooling includes inner coaxial powder feeding laser cladding head, floating mounting mechanism, annular follow-up sealing gas cover and numerical control rotary tooling;The lower end of the gas cover is provided with an annular elastic sealing lip, and the inside is provided with a central inner flow guide cavity, an outer ring annular flow guide cavity and a spiral flow guide rib.A stepped positioning seat and a radial adjustable compression assembly are used for coaxial positioning of different specifications of flanges.During repair, protective gas is continuously introduced, the flange is rotated relative to the gas cover and laser cladding is performed, and the floating mounting mechanism maintains the sealing lip in contact with the flange end face through axial compensation and elastic pre-tensioning.

Description

Technical Field

[0001] This invention belongs to the field of laser additive manufacturing and surface repair technology, specifically relating to an annular follow-up protective fixture for laser cladding of high-pressure flange sealing surfaces, a laser cladding system including the fixture, and a method for laser cladding repair of high-pressure flange annular sealing surfaces using the fixture. Background Technology

[0002] High-pressure flanges are crucial sealing components in coal chemical, synthetic ammonia, and high-pressure oil and gas transmission systems. During long-term service, the flange's annular sealing surface may be subjected to media erosion, corrosive media, and alternating loads, resulting in pitting, grooves, or localized spalling, thus affecting the flange's sealing reliability.

[0003] Laser cladding features relatively low heat input, low substrate dilution rate, and good adhesion between the cladding layer and the substrate, making it suitable for repairing damaged flange sealing surfaces. However, the high-temperature molten pool formed during laser cladding is prone to oxidation or gas absorption if it comes into direct contact with air; therefore, a stable protective atmosphere is typically required in the cladding area.

[0004] Existing laser cladding gas protection structures can employ open-air blowing, protective covers surrounding the laser cladding head, or the formation of annular protective airflow. For high-pressure flange annular sealing surfaces requiring continuous rotary cladding, it is also necessary to consider the continuous fit between the protective structure and the flange end face, the distribution of protective gas throughout the annular area, and the coaxial positioning and clamping of flanges of different specifications.

[0005] Therefore, it is necessary to provide a special protective tooling that combines a protective cavity covering the entire flange annular sealing surface, axial floating fit, annular gas diversion, and multi-specification flange rotation positioning. Summary of the Invention I. Technical problems to be solved

[0006] This invention aims to improve the following problems during the rotary laser cladding process of high-pressure flanges: insufficient fit stability between the protective structure and the flange end face, uneven gas protection across the entire annular sealing surface, limited compatibility of coaxial clamping of flanges of different specifications, and insufficient coordination between gas protection and rotary cladding. II. Technical Solution

[0007] This invention provides an annular follow-up protective fixture for laser cladding of high-pressure flange sealing surfaces, including an inner coaxial powder feeding laser cladding head 1, a laser cladding head floating mounting mechanism 2, an annular follow-up sealing gas cover 3, a high-pressure flange 4, and a CNC rotary fixture 5.

[0008] An annular follower-type sealing gas cover 3 is arranged around the working end of the inner coaxial powder feeding laser cladding head 1, and its inner diameter is larger than the maximum outer diameter of the annular sealing surface of the high-pressure flange 4 to be repaired. An annular elastic sealing lip 32 is provided around the lower opening of the annular follower-type sealing gas cover 3. The lower opening, the annular elastic sealing lip 32 and the end face of the high-pressure flange 4 together form a protective cavity covering the entire annular sealing surface.

[0009] The laser cladding head floating mounting mechanism 2 is connected between the inner coaxial powder feeding laser cladding head 1 and the annular follower sealing gas cover 3. The laser cladding head floating mounting mechanism 2 is equipped with an elastic element, preferably a return spring. The elastic element provides a preload force to the annular follower sealing gas cover 3 toward the end face of the high-pressure flange 4, so that the annular follower sealing gas cover 3 can float and compensate along the axial direction.

[0010] The annular follower-type sealing gas cover 3 has a central inner guide cavity 33 and an outer annular guide cavity 34 coaxially arranged inside. The outer annular guide cavity 34 is located radially outside the central inner guide cavity 33, and a spiral guide rib 35 is arranged between the two guide cavities. The side wall of the annular follower-type sealing gas cover 3 is provided with at least one air inlet joint 31 communicating with the guide cavity. After the protective gas enters the guide cavity through the air inlet joint 31, it diffuses into the protective cavity under the action of the guide cavity and the spiral guide rib 35.

[0011] The CNC rotary fixture 5 includes a rotary base 53, a stepped positioning seat 51, and multiple sets of radially adjustable clamping components 52 arranged circumferentially. The stepped positioning seat 51 has multiple annular positioning steps with different diameters centered on the rotation center. High-pressure flanges 4 of different specifications can select the corresponding annular positioning steps for coaxial positioning. The clamping ends of each radially adjustable clamping component 52 are set towards the rotation center and can adjust the radial position of the clamping ends relative to the rotation center, thereby clamping and positioning from the outer edge of the high-pressure flange 4.

[0012] During assembly, the central axis of the annular follower sealing gas cover 3 is aligned with the rotation center of the CNC rotary fixture 5. During operation, the CNC rotary fixture 5 drives the high-pressure flange 4 to rotate relative to the annular follower sealing gas cover 3. During this relative rotation, when there is a height change at the flange end face, the laser cladding head floating installation mechanism 2 performs axial floating compensation, and the annular elastic sealing lip 32 is kept in contact with the flange end face by the pre-tightening effect of the elastic element.

[0013] Furthermore, the axial floating compensation stroke of the laser cladding head floating mounting mechanism 2 is 3 to 10 mm.

[0014] Furthermore, the annular follow-up sealing gas cover 3 and the laser cladding head floating mounting mechanism 2 are detachably sealed, and the laser cladding head floating mounting mechanism 2 is provided with an interface for connecting the inner coaxial powder feeding laser cladding head 1.

[0015] Furthermore, the annular elastic sealing lip 32 can be made of high-temperature resistant rubber ring or metal flexible sealing ring, with a heat resistance temperature of not less than 200℃.

[0016] Furthermore, the annular follow-up sealing gas cover 3 can be bell-shaped or cylindrical, and can be made of stainless steel or copper.

[0017] Furthermore, the air inlet connector 31 can be configured as two and arranged opposite each other in the radial direction; for a larger annular follow-up sealing gas cover 3, four air inlet connectors 31 can be evenly arranged in the circumferential direction.

[0018] Furthermore, the radially adjustable clamping assembly 52 can be configured as six groups and evenly arranged around the circumference of the graded positioning step seat 51.

[0019] Furthermore, the graded positioning step seat 51 can be equipped with multiple annular positioning steps corresponding to the high-pressure flange 4 of DN25 to DN300 specifications.

[0020] Furthermore, the rotary base 53 is equipped with a drive motor, which is used to drive the high-pressure flange 4, which is clamped and positioned by the radially adjustable clamping assembly 52, to rotate around the rotation center.

[0021] The present invention also provides a laser cladding system, including an inner coaxial powder feeding laser cladding head 1 and the above-mentioned annular follow-up protective fixture. The inner coaxial powder feeding laser cladding head 1 is connected to the annular follow-up sealing gas cover 3 through a laser cladding head floating mounting mechanism 2.

[0022] This invention also provides a method for laser cladding repair of high-pressure flange sealing surfaces. According to the specifications of the high-pressure flange 4 to be repaired, a corresponding annular positioning step is selected, and the radial clamping position of the radially adjustable clamping assembly 52 is adjusted so that the flange rotation axis is aligned with the rotation center; the central axis of the annular follower sealing gas cover 3 is aligned with the rotation center, and the annular elastic sealing lip 32 is flexibly fitted with the flange end face; after continuously introducing protective gas, the high-pressure flange 4 is rotated relative to the annular follower sealing gas cover 3 and laser cladding is performed; during the relative rotation, the axial compensation and elastic pre-tightening of the floating installation mechanism 2 are used to maintain the contact between the sealing lip and the flange end face. III. Beneficial Effects

[0023] The present invention has at least the following beneficial effects.

[0024] The annular follow-up sealing gas cover 3 covers the entire annular sealing surface of the high-pressure flange 4. The annular elastic sealing lip 32 cooperates with the elastic element in the floating installation mechanism 2, so that the gas cover can perform axial floating compensation during the relative rotation of the flange, which is conducive to continuously maintaining the fit of the boundary of the protection cavity.

[0025] The central inner guide cavity 33, the outer annular guide cavity 34, and the spiral guide rib 35 work together to guide the protective gas, which helps to improve the circumferential distribution of the protective gas in the entire annular protection area.

[0026] The graded positioning step seat 51, in conjunction with multiple sets of radially adjustable clamping components 52, enables high-pressure flanges 4 of different specifications to be positioned and clamped on their outer edges based on a common rotation center, which helps to maintain the relative consistency between the flange rotation axis and the central axis of the gas hood.

[0027] The aforementioned tooling allows for the coordinated use of full-annular gas protection, axial floating fit, and multi-specification coaxial rotary positioning within the same device.

[0028] The described cladding repair method combines coaxial positioning, full-ring protective gas flow, flange relative gas hood rotation, and axial floating bonding into the same continuous operation process, which helps to improve the stability of the high-pressure flange annular sealing surface rotation laser cladding process. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall exploded assembly of the present invention.

[0030] Figure 2 This is a schematic longitudinal cross-sectional view of the annular follow-up sealing gas cover of the present invention.

[0031] Figure 3 This is a top view of the CNC rotary tooling structure of the present invention.

[0032] Reference numerals: 1-Inner coaxial powder feeding laser cladding head; 2-Floating mounting mechanism for laser cladding head; 3-Annular follow-up sealing gas cover; 31-Air inlet connector; 32-Annular elastic sealing lip; 33-Central inner guide cavity; 34-Outer annular guide cavity; 35-Helical guide rib; 4-High pressure flange; 5-CNC rotary fixture; 51-Graded positioning step seat; 52-Radially adjustable clamping assembly; 53-Rotary base. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments. The following embodiments are used to illustrate the structure, gas protection method and cladding repair process of the present invention, and do not constitute a limitation on the scope of protection.

[0034] like Figures 1-3As shown, according to the specifications of the high-pressure flange 4 to be repaired, the high-pressure flange 4 is placed on the annular positioning step corresponding to the graded positioning step seat 51, and is clamped and positioned from the outer edge of the flange by multiple sets of radially adjustable clamping components 52. By adjusting the clamping stroke of the radially adjustable clamping components 52, the rotation axis of the high-pressure flange 4 is aligned with the rotation center. The positions of the inner coaxial powder feeding laser cladding head 1 and the annular follow-up sealing gas cover 3 are adjusted so that the central axis of the gas cover coincides with the rotation center, and the annular elastic sealing lip 32 contacts the end face of the high-pressure flange 4.

[0035] Argon gas is continuously introduced into the guide cavity through the inlet connector 31. Under the combined action of the central inner guide cavity 33, the outer annular guide cavity 34, and the spiral guide rib 35, the protective gas diffuses into the protective cavity covering the entire flange annular sealing surface. Subsequently, the CNC rotary fixture 5 is activated, causing the high-pressure flange 4 to rotate around the rotation center relative to the annular follower sealing gas cover 3, and laser cladding is performed by the inner coaxial powder feeding laser cladding head 1.

[0036] During the relative rotation cladding process, when there is a height change at the flange end face, the floating installation mechanism 2 of the laser cladding head floats and compensates along the axial direction. Its internal elastic element provides a pre-tightening effect to the annular follow-up sealing gas cover 3, so that the annular elastic sealing lip 32 remains in contact with the flange end face. Example 1: Small and medium-sized flanges from DN25 to DN80

[0037] The high-pressure flange 4 is placed on the corresponding positioning step of the graded positioning step seat 51, and six sets of radially adjustable clamping components 52 clamp the outer edge of the flange circumferentially. The flange rotation speed can be set to 0.5–3 r / min, and the laser cladding scanning linear speed can be set to 100–300 mm / min. The annular follow-up sealing gas cover 3 adopts a bell-shaped stainless steel structure, with two radially opposite 1 / 4-inch air inlet connectors 31. The interior is equipped with a central inner guide cavity 33, an outer annular guide cavity 34, and a spiral guide rib 35. The lower end is equipped with a silicone rubber annular elastic sealing lip 32 with a heat resistance temperature of not less than 200℃. The laser cladding head floating installation mechanism 2 is equipped with a return spring. The axial floating compensation stroke can be set to 3–8 mm, and the spring preload can be set to 5–12 N. Argon gas with a purity of not less than 99.999% can be used during operation, with a supply pressure of 0.12–0.18 MPa and a flow rate of 18–22 L / min. Example 2: DN100 medium-sized high-pressure flange

[0038] The annular follow-up sealing gas cover 3 can be a cylindrical stainless steel structure with an inner diameter of 150 mm and a wall thickness of 3 mm. A flexible metal sealing ring is set at the lower end. Two air inlet connectors 31 are arranged opposite each other, and the argon flow rate can be set to 25 L / min. The graded positioning step seat 51 is selected with a positioning step corresponding to the DN100 flange. The radially adjustable clamping component 52 finely adjusts the clamping stroke. The axial floating compensation stroke of the laser cladding head floating installation mechanism 2 can be set to 4-9 mm. Example 3: Large Diameter High-Pressure Flanges (DN150~DN300)

[0039] The annular follow-up sealing gas cover 3 can be made of copper, with an inner diameter of 400 mm and a wall thickness of 4 mm. The lower end is equipped with a silicone rubber annular elastic sealing lip 32 with a heat resistance temperature not lower than 250℃. Four air inlet joints 31 are evenly arranged circumferentially around the gas cover. The single-channel argon gas flow rate can be set to 12 L / min, and the total flow rate can be set to 48 L / min. The axial floating compensation stroke of the laser cladding head floating mounting mechanism 2 can be set to 5–10 mm. The graded positioning step seat 51 uses a positioning step corresponding to the large-diameter flange, and the radially adjustable clamping assembly 52 increases the clamping stroke.

Claims

1. A ring-shaped follow-up protective fixture for laser cladding of high-pressure flange sealing surfaces, comprising an inner coaxial powder feeding laser cladding head (1) and a CNC rotary fixture (5), characterized in that: It also includes a laser cladding head floating mounting mechanism (2) and an annular follow-up sealing gas cover (3); The annular follow-up sealing gas cover (3) is set around the working end of the inner coaxial powder feeding laser cladding head (1), and its inner diameter is larger than the maximum outer diameter of the annular sealing surface of the high pressure flange (4) to be repaired. The lower end opening of the annular follow-up sealing gas cover (3) is provided with an annular elastic sealing lip (32). The lower end opening, the annular elastic sealing lip (32) and the end face of the high pressure flange (4) together form a protective cavity covering the annular sealing surface. The laser cladding head floating installation mechanism (2) is connected between the inner coaxial powder feeding laser cladding head (1) and the annular follower sealing gas cover (3), and is provided with an elastic element. The elastic element provides a pre-tightening force to the annular follower sealing gas cover (3) toward the end face of the high pressure flange (4), so that the annular follower sealing gas cover (3) can float and compensate along the axial direction. The annular follow-up sealing gas cover (3) is coaxially provided with a central inner guide cavity (33) and an outer annular guide cavity (34) located radially outside the central inner guide cavity (33). A spiral guide rib (35) is provided between the two guide cavities. At least one air inlet connector (31) communicating with the guide cavity is provided on the side wall of the annular follow-up sealing gas cover (3). The CNC rotary fixture (5) includes a rotary base (53), a graded positioning step seat (51), and multiple sets of radially adjustable clamping components (52) arranged circumferentially. The graded positioning step seat (51) has multiple annular positioning steps with different diameters centered on the rotation center, used for coaxial positioning of high-pressure flanges (4) of different specifications. The clamping ends of each of the radially adjustable clamping components (52) are arranged facing the rotation center, and the radial position of the clamping ends relative to the rotation center is adjustable, used for clamping and positioning from the outer edge of the high-pressure flange (4). The central axis of the annular follower sealing gas cover (3) coincides with the rotation center. The CNC rotary tooling (5) is used to drive the high pressure flange (4) to rotate relative to the annular follower sealing gas cover (3). During the relative rotation, the elastic element keeps the annular elastic sealing lip (32) in contact with the end face of the high pressure flange (4) through the axial floating compensation.

2. The annular follow-up protective fixture for laser cladding of high-pressure flange sealing surfaces according to claim 1, characterized in that: The elastic element in the laser cladding head floating mounting mechanism (2) is a reset spring, and the axial floating compensation stroke of the laser cladding head floating mounting mechanism (2) is 3 to 10 mm.

3. The annular follow-up protective fixture for laser cladding of high-pressure flange sealing surfaces according to claim 1, characterized in that: The annular follow-up sealing gas cover (3) and the laser cladding head floating mounting mechanism (2) are detachably sealed. The laser cladding head floating mounting mechanism (2) is provided with an interface for connecting the inner coaxial powder feeding laser cladding head (1).

4. The annular follow-up protective fixture for laser cladding of high-pressure flange sealing surfaces according to claim 1, characterized in that: The annular elastic sealing lip (32) is a high-temperature resistant rubber ring or a metal flexible sealing ring with a heat resistance temperature of not less than 200℃.

5. The annular follow-up protective fixture for laser cladding of high-pressure flange sealing surfaces according to claim 1, characterized in that: The annular follow-up sealing gas cover (3) is bell-shaped or cylindrical and made of stainless steel or copper.

6. The annular follow-up protective fixture for laser cladding of high-pressure flange sealing surfaces according to claim 1, characterized in that: The number of the air inlet connectors (31) is two, and the two air inlet connectors (31) are arranged opposite each other radially along the annular follow-up sealing gas cover (3).

7. The annular follow-up protective fixture for laser cladding of high-pressure flange sealing surfaces according to claim 1, characterized in that: The number of the air inlet connectors (31) is four, and the four air inlet connectors (31) are evenly arranged around the circumference of the annular follow-up sealing gas cover (3).

8. The annular follow-up protective fixture for laser cladding of high-pressure flange sealing surfaces according to claim 1, characterized in that: The radially adjustable clamping assembly (52) consists of six groups and is evenly arranged around the circumference of the graded positioning step seat (51).

9. The annular follow-up protective fixture for laser cladding of high-pressure flange sealing surfaces according to claim 1, characterized in that: The multiple annular positioning steps of the graded positioning step seat (51) are used to position the high-pressure flange (4) of DN25 to DN300 specifications.

10. The annular follow-up protective fixture for laser cladding of high-pressure flange sealing surfaces according to claim 1, characterized in that: The rotating base (53) is equipped with a drive motor, which is used to drive the high-pressure flange (4) that is clamped and positioned by the radially adjustable clamping assembly (52) to rotate around the rotation center.

11. A laser cladding system, comprising an inner coaxial powder-feeding laser cladding head (1), characterized in that: It also includes the annular follow-up protective fixture for laser cladding of high-pressure flange sealing surface as described in any one of claims 1 to 10, wherein the inner coaxial powder feeding laser cladding head (1) is connected to the annular follow-up sealing gas cover (3) through the laser cladding head floating installation mechanism (2).

12. A method for laser cladding repair of high-pressure flange sealing surfaces using the annular follow-up protective fixture for laser cladding of high-pressure flange sealing surfaces according to any one of claims 1 to 10, characterized in that, include: According to the specifications of the high-pressure flange (4) to be repaired, the high-pressure flange (4) is placed on the annular positioning step corresponding to the graded positioning step seat (51), and the radial clamping positions of multiple sets of radially adjustable clamping components (52) are adjusted and clamped and positioned from the outer edge of the high-pressure flange (4) so ​​that the rotation axis of the high-pressure flange (4) is consistent with the rotation center. Adjust the positions of the inner coaxial powder feeding laser cladding head (1) and the annular follow-up sealing gas cover (3) so that the central axis of the annular follow-up sealing gas cover (3) coincides with the rotation center, and make the annular elastic sealing lip (32) flexibly fit with the end face of the high pressure flange (4) to form a protective cavity covering the annular sealing surface of the high pressure flange (4). Protective gas is continuously introduced into the guide cavity through the air inlet connector (31), so that the protective gas diffuses into the protective cavity under the action of the central inner guide cavity (33), the outer annular guide cavity (34) and the spiral guide rib (35); Under the condition of continuous supply of protective gas, the high pressure flange (4) is rotated around the rotation center relative to the annular follow-up sealing gas cover (3), and the annular sealing surface of the high pressure flange (4) is laser clad by the inner coaxial powder feeding laser cladding head (1). During the rotation of the high-pressure flange (4) relative to the annular follow-up sealing gas cover (3), the axial floating compensation of the laser cladding head floating installation mechanism (2) and the pre-tightening effect of the elastic element are used to keep the annular elastic sealing lip (32) in contact with the end face of the high-pressure flange (4).

13. The laser cladding repair method for high-pressure flange sealing surfaces according to claim 12, characterized in that: For high-pressure flanges (4) with specifications of DN25 to DN80, the rotation speed of the high-pressure flange (4) is 0.5 to 3 r / min, and the laser cladding scanning line speed is 100 to 300 mm / min.

14. The laser cladding repair method for high-pressure flange sealing surfaces according to claim 12, characterized in that: For high-pressure flanges (4) with specifications of DN25 to DN80, the protective gas is argon with a purity of not less than 99.999%, the gas supply pressure is 0.12 to 0.18 MPa, and the gas supply flow rate is 18 to 22 L / min.

15. The laser cladding repair method for high-pressure flange sealing surfaces according to claim 12, characterized in that: For high-pressure flanges (4) with specifications of DN150~DN300, the annular follow-up sealing gas cover (3) is uniformly provided with four air inlet joints (31) along the circumference, the single-channel argon flow rate is 12 L / min, the total flow rate is 48 L / min, and the axial floating compensation stroke of the laser cladding head floating installation mechanism (2) is 5~10 mm.

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