Manufacturing process of corrosion-resistant rotating tower friction ring for deep sea FSO

Abstract

The present application relates to the technical field of marine equipment manufacturing, in particular to a kind of deep sea FSO corrosion-resistant turret friction ring manufacturing process, by twice high temperature tempering, the internal stress of base material is reduced, and by leaving margin A and margin B when designing base material size, deformation space is left for friction ring, so that the deformation amount of the finally formed friction ring is reduced.Simultaneously by multiple welding machines simultaneously surfacing on base material, reduce the instantaneous heat input amount of the same position on base material, so that the heat input amount received by base material is uniformly distributed, the thermal expansion and cold shrink of each position of base material are synchronized, thereby reducing the deformation caused by the uneven heat input and excessive stress of the friction ring caused by surfacing. Thus it can be realized to reduce the uneven heat input and excessive stress caused by surfacing, and the deformation of the friction ring is increased.

Description

Technical Field

[0001] This invention relates to the field of marine equipment manufacturing technology, specifically to a manufacturing process for a corrosion-resistant turret friction ring for deep-sea FSOs. Background Technology

[0002] As a core piece of equipment for deep-sea oil extraction, the normal operation of a floating storage and offloading (FSO) unit is highly dependent on a single-point mooring (SPM) system. The SPM system provides the hull with a fixed center of rotation, allowing the vessel to adjust its bow orientation at any time to reduce the impact of sea waves on the hull and greatly enhance the vessel's ability to withstand harsh environments.

[0003] Currently, the docking of the turret of a current-operated steam locomotive (FSO) with a single-point mooring system (SPM) typically uses a sliding seal connection. Under this connection method, the dimensional accuracy requirements for the friction ring, a critical connecting component, are extremely stringent, resulting in high manufacturing costs. However, due to the harsh operating conditions at sea, the interface is in constant contact with highly corrosive liquids such as seawater and crude oil, necessitating periodic replacement of the friction ring. Replacing the interface ring carries the risk of downtime and is also costly. The industry commonly employs a welding process, depositing a certain thickness of corrosion-resistant alloy onto the steel surface to enhance the corrosion resistance of the component. However, the enormous welding stress introduced by welding significantly increases the manufacturing difficulty of the interface ring. Furthermore, as a large-sized workpiece, the friction ring is more susceptible to uneven heat input and excessive stress due to welding, increasing the risk of deformation. Summary of the Invention

[0004] The technical solution adopted by this invention to solve its technical problem is: to provide a manufacturing process for a corrosion-resistant turret friction ring for deep-sea FSOs, comprising:

[0005] Step S1: Design the substrate dimensions: Add allowance A and allowance B to the final formed friction ring.

[0006] Step S2: Perform two high-temperature tempering treatments on the substrate;

[0007] Step S3: Simultaneous surfacing welding of the substrate is performed using multiple welding machines. The surfacing welding process is divided into a first stage and a second stage. After the first stage of surfacing welding is completed, the substrate is flipped over using a crane and clamping fixture. After the relative position of the welding machine and the substrate is corrected by a laser level, the second stage of surfacing welding is performed on the substrate simultaneously using multiple welding machines.

[0008] Step S4: Place the substrate and the clamping fixture into the heating furnace for post-weld heat treatment. After exiting the furnace, measure and record the deformation of the substrate at multiple points.

[0009] Step S5: The substrate is flipped multiple times using a crane and clamping fixture, and then rough machining, multiple semi-finishing, hole machining, finishing, and finishing rework are performed in sequence. After each process is completed, the clamping fixture is released for aging and static treatment, and the deformation is measured.

[0010] Step S6: Perform dimensional inspection on the final formed friction ring;

[0011] Step S7: The final formed friction ring is lifted, packaged, and transported using lifting fixtures.

[0012] Furthermore, the two high-temperature tempering processes described in step S1 are as follows: the initial temperature is ≤350℃, the temperature is increased to 630-670℃ at a rate of ≤80℃ / h and held for 3.5-4.5h, after which the temperature is increased to 880-920℃ and held for 7.5-9.0h, and then water-cooled for 60-90min; after water-cooling, the temperature is increased again to 330-370℃ and held for 3.5-6.5h, after which the temperature is increased to 600-640℃ at a rate of ≤80℃ / h and held for 11.5-13.0h, followed by air cooling; after air cooling, the substrate is rough-machined, and after rough machining, the temperature is increased to 330-370℃ at a rate of ≤80℃ / h and held for 3.5-4.5h, after which the temperature is increased to 550-600℃, and after which the temperature is held for 6.0-8.0h, followed by air cooling.

[0013] Furthermore, the welding method in step S3 is automatic argon arc welding.

[0014] Furthermore, multiple welding machines are evenly distributed along the outer periphery of the substrate.

[0015] Furthermore, the deformation measurement includes flatness detection, perpendicularity detection, roundness detection, and runout detection.

[0016] Furthermore, the post-weld heat treatment process is as follows: slowly heat to 570±10℃ at a heating rate of <100℃ / h and hold for 4 hours, then slowly cool to below 200℃ at a cooling rate of <100℃ / h and air cool.

[0017] Furthermore, during post-weld heat treatment, the furnace is opened after cooling to 170°C.

[0018] Furthermore, the clamping fixture includes a frame and multiple clamping plate modules disposed on the frame. The frame is provided with a lifting ring for hoisting by a crane. Each clamping plate module includes two clamping plates, which are fixed relative to each other by bolts, and the two clamping plates are respectively located at both ends of the substrate axial direction.

[0019] Furthermore, the lifting fixture includes a support ring and multiple fixing components. The support ring is provided with a second lifting ring, which is used to cooperate with a crane. The support ring is connected to the final formed friction ring through the fixing components. The fixing components include a flange and a stud. The two ends of the stud are respectively fixed relative to the support ring and the base material. The flange is sleeved on the stud. The connection between the flange and the stud is fixed by bolts and nuts.

[0020] Furthermore, the stud, support ring, and finally formed friction ring are all fixed by threads.

[0021] The beneficial effects of this invention are as follows: By performing two high-temperature tempering processes, the internal stress of the substrate is reduced. Furthermore, by allowing allowances A and B in the substrate size design, deformation space is provided for the friction ring, resulting in a reduced deformation of the final formed friction ring. Simultaneously, by using multiple welding machines to simultaneously weld the substrate, the instantaneous heat input at the same location on the substrate is reduced, ensuring a uniform distribution of heat input and synchronized thermal expansion and contraction across the substrate. This reduces deformation caused by uneven heat input during welding. Therefore, the increased deformation of the friction ring due to uneven heat input and excessive stress caused by welding is reduced. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] In the picture: Figure 1 This is a cross-sectional view of the substrate provided in this invention during the first stage of welding.

[0024] Figure 2 This is a cross-sectional view of the substrate provided in this invention during the second stage of overlay welding.

[0025] Figure 3 This is a schematic diagram showing the positional distribution of the multiple welding machines described in this invention;

[0026] Figure 4 This is a three-dimensional structural diagram of the hoisting fixture described in this invention;

[0027] Figure 5 for Figure 4 A sectional view of the partial structure shown;

[0028] Figure 6 This is a bottom view of the fixture used in this invention to hold the substrate.

[0029] Figure 7 for Figure 6 A three-dimensional structural diagram of part of the structure shown in the image;

[0030] Figure 8This is a schematic diagram of the first high-temperature tempering process described in this invention;

[0031] Figure 9 This is a schematic diagram of the second high-temperature tempering process described in this invention.

[0032] Explanation of reference numerals in the attached drawings: 100, base material; 101, allowance A; 102, allowance B; 103, final formed friction ring; 200, welding machine; 301, support ring; 3011, lifting ring two; 302, flange; 303, stud; 401, frame; 4011, lifting ring one; 402, clamping plate; 402, bolt. Detailed Implementation

[0033] To make the technical problem to be solved, the technical solution, and the beneficial effects of this invention clearer, the invention will now be described in detail with reference to the accompanying drawings. This drawing is a simplified schematic diagram, illustrating only the basic aspects of the invention, and therefore only shows the components relevant to the invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0034] Please refer to Figure 1 and Figure 2 This invention provides a manufacturing process for a corrosion-resistant turret friction ring for deep-sea FSOs, comprising:

[0035] Step S1: Design the dimensions of the substrate 100: Add allowance A101 and allowance B102 to the final formed friction ring 103.

[0036] By setting the allowances A101 and B102, the strength of the substrate 100 is enhanced while providing deformation space for the substrate 100, so that the final formed friction ring 103 is not prone to excessive deformation.

[0037] Specifically, in this embodiment, the base material 100 is a forged ring integrally formed by ring forging, with a specification of ASTM A694F60.

[0038] Step S2: Perform two high-temperature tempering treatments on the substrate 100;

[0039] Please refer to Figure 8 and Figure 9As shown, the two high-temperature tempering processes are as follows: the initial temperature is ≤350℃, the temperature is increased to 630-670℃ at a rate of ≤80℃ / h and held for 3.5-4.5h, after which the temperature is increased to 880-920℃ and held for 7.5-9.0h, and then water-cooled for 60-90min; after water-cooling, the temperature is increased again to 330-370℃ and held for 3.5-6.5h, after which the temperature is increased to 600-640℃ at a rate of ≤80℃ / h and held for 11.5-13.0h, followed by air cooling; after air cooling, the substrate is rough-machined, and after rough machining, the temperature is increased to 330-370℃ at a rate of ≤80℃ / h and held for 3.5-4.5h, after which the temperature is increased to 550-600℃, and after which the temperature is held for 6.0-8.0h, followed by air cooling.

[0040] Step S3: The substrate 100 is simultaneously welded by multiple welding machines 200. The welding process is divided into a first stage and a second stage. After the first stage of welding is completed, the substrate 100 is turned over by a crane with clamping fixtures. After the relative position of the welding machine 200 and the substrate 100 is corrected by a laser level, the substrate 100 is simultaneously welded by multiple welding machines 200 in the second stage.

[0041] Specifically, in this embodiment, the welding method used is automated TIG welding. Compared with other welding methods such as CO2 gas shielded welding and submerged arc welding, automated TIG welding requires less heat input.

[0042] Furthermore, multiple welding machines 200 are evenly distributed along the outer periphery of the substrate 100. In this embodiment, four welding machines 200 are provided.

[0043] Please refer to Figure 1 and Figure 2 As shown, the weld overlay surfaces on the substrate 100 are N1, W1a, W1b, W1c and W1a, P1a, P1c, P2, respectively. In the first stage, a portion of N1, W1a, W1b, and W1c are welded simultaneously. In the second stage, the remaining portion of N1, P1a, P1c, and P2 are welded simultaneously.

[0044] The specific steps of welding overlay include:

[0045] Step 1: Four welding machines 200 simultaneously perform surfacing welding at N1, W1a, W1b, and W1c respectively. The welding machine 200 responsible for W1a is transferred to N1 after the surfacing welding process is completed in advance, and performs surfacing welding synchronously with the other welding machines 200 until the first stage of surfacing welding is completed.

[0046] Step 2: Perform finished weld overlay dimension and NDT inspection on the weld overlay layers at W1a, W1b, and W1c.

[0047] Step 3: Use a crane and clamping fixtures to flip the base material 100 over.

[0048] Step 4: Correct the relative positions of the welding machine 200 and the substrate 100 using a laser level;

[0049] Step 5: Two of the welding machines 200 continue to complete the surfacing of the remaining part of N1, while the remaining two welding machines 200 simultaneously surfacing P1a and P1c.

[0050] Step 6: After N1 is completed, the two welding machines 200 are transferred to P1a and P1b for overlay welding.

[0051] Step 7: After P1a and P1b are completed, the welding machine 200 performs overlay welding on P2.

[0052] Step 8: Perform finished weld overlay dimension and NDT inspection on the weld overlay layers at N1, P1a, P1b, P1c, and P2.

[0053] Step S4: Place the substrate 100 and the clamping fixture into the heating furnace for post-weld heat treatment. After taking it out of the furnace, measure and record the deformation of the substrate 100 at multiple points (usually 6-8 points).

[0054] The post-weld heat treatment process is as follows: The temperature is slowly heated to 570±10℃ at a heating rate of <100℃ / h and held for 4 hours, followed by slow cooling to below 200℃ at a cooling rate of <100℃ / h for air cooling. The furnace must be cooled to 170℃ before opening after post-weld heat treatment. In this embodiment, the planar runout and circular runout of the substrate 100 after post-weld heat treatment are both less than 0.3mm.

[0055] Step S5: Using a crane and clamping fixtures, the base material 100 is flipped multiple times and subjected to rough machining, multiple semi-finishing, hole machining, finishing, and finishing rework processes in sequence. After each process, the clamping fixtures are released for aging and static treatment, and the deformation is measured. By performing aging and static treatment and measuring the deformation after each machining operation, the next machining plan can be adjusted, resulting in a friction ring with minimal dimensional error in the final product.

[0056] Specifically, deformation measurement includes flatness inspection, perpendicularity inspection, roundness inspection, and runout inspection. Roughing, multiple semi-finishing, hole machining, finishing, and finishing rework processes are performed using a double-gantry vertical lathe.

[0057] Please refer to Figure 6 and Figure 7The clamping fixture includes a frame 401 and multiple clamping plate modules 402 mounted on the frame 401. Each clamping plate module 402 includes two clamping plates, which are fixed together by bolts 402, and are located at opposite ends of the substrate 100 along its axial direction. The frame 401 is equipped with lifting rings 4011 for crane lifting. When flipping the substrate 100, the multiple clamping modules and the substrate 100 are first fixed relative to each other by bolts 402, thereby fixing the clamping fixture and the substrate 100 relative to each other. Then, the crane, in conjunction with the lifting rings 4011, lifts and flips one side of the entire clamping fixture, thereby flipping the substrate 100.

[0058] Step S6: Perform dimensional inspection on the final formed friction ring 103;

[0059] The dimensional inspection results of the final formed friction ring 103 in this invention are shown in Table 1.

[0060] Table 1. Dimensional inspection results of the final formed friction ring

[0061]

[0062] According to the test results shown in Table 1, the friction ring manufactured by the manufacturing process described in this embodiment meets the size specifications and is not easily affected by excessive stress caused by welding and uneven heat input.

[0063] Step S7: The final formed friction ring 103 is hoisted, packaged, and transported using hoisting equipment.

[0064] Please refer to Figure 4 and Figure 5 The lifting fixture includes a support ring 301 and multiple fixing components. The support ring 301 has a second lifting ring 3011, which is used to cooperate with a crane. The support ring 301 is connected to the final formed friction ring 103 via the fixing components. The fixing components include flanges 302 and studs 303. The two ends of the studs 303 are respectively fixed to the support ring 301 and the base material 100 via threads. Two flanges 302 are fitted onto the studs 303, and the two flanges 302 are fixed to each other by multiple bolts 402 and nuts. The connection between the flanges 302 and the studs 303 is fixed by bolts 402 and nuts.

[0065] Two high-temperature tempering processes reduce the internal stress of the substrate 100. By allowing allowances A101 and B102 in the design of the substrate 100 dimensions, deformation space is provided for the friction ring, resulting in reduced deformation of the final formed friction ring 103. Simultaneously, multiple welding machines 200 perform weld overlay on the substrate 100, reducing the instantaneous heat input at the same location on the substrate 100. This ensures a uniform distribution of heat input across the substrate 100, and synchronized thermal expansion and contraction at all locations, thereby reducing deformation caused by uneven heat input during welding. This effectively reduces the increased deformation of the friction ring due to uneven heat input and excessive stress caused by welding.

Claims

1. A manufacturing process for a corrosion-resistant turret friction ring for deep-sea FSOs, characterized in that, include: Step S1: Design the substrate dimensions: Add allowance A and allowance B to the final formed friction ring; Step S2: Perform two high-temperature tempering treatments on the substrate; Step S3: Simultaneous surfacing welding of the substrate is performed using multiple welding machines. The surfacing welding process is divided into a first stage and a second stage. After the first stage of surfacing welding is completed, the substrate is flipped over using a crane and clamping fixture. After the relative position of the welding machine and the substrate is corrected by a laser level, the second stage of surfacing welding is performed on the substrate simultaneously using multiple welding machines. Step S4: Place the substrate and the clamping fixture into the heating furnace for post-weld heat treatment. After exiting the furnace, measure and record the deformation of the substrate at multiple points. Step S5: The substrate is flipped multiple times using a crane and clamping fixture, and then rough machining, multiple semi-finishing, hole machining, finishing, and finishing rework are performed in sequence. After each process is completed, the clamping fixture is released for aging and static treatment, and the deformation is measured. Step S6: Inspect the dimensions of the final formed friction ring; Step S7: The final formed friction ring is lifted, packaged, and transported using lifting fixtures.

2. The manufacturing process for the corrosion-resistant turret friction ring of a deep-sea FSO according to claim 1, characterized in that: The two high-temperature tempering processes described in step S1 are as follows: the initial temperature is ≤350℃, the temperature is increased to 630-670℃ at a rate of ≤80℃ / h and held for 3.5-4.5h, after which the temperature is increased to 880-920℃ and held for 7.5-9.0h, and then water-cooled for 60-90min; after water-cooling, the temperature is increased again to 330-370℃ and held for 3.5-6.5h, after which the temperature is increased to 600-640℃ at a rate of ≤80℃ / h and held for 11.5-13.0h, followed by air cooling; after air cooling, the substrate is rough-machined, and after rough machining, the temperature is increased to 330-370℃ at a rate of ≤80℃ / h and held for 3.5-4.5h, after which the temperature is increased to 550-600℃, and after which the temperature is held for 6.0-8.0h, followed by air cooling.

3. The manufacturing process for the corrosion-resistant turret friction ring of a deep-sea FSO according to claim 1, characterized in that: In step S3, the welding method is automatic argon arc welding.

4. The manufacturing process for the corrosion-resistant turret friction ring of a deep-sea FSO according to claim 1, characterized in that: Multiple welding machines are evenly distributed along the outer periphery of the substrate.

5. The manufacturing process for the corrosion-resistant turret friction ring of a deep-sea FSO according to claim 1, characterized in that: The deformation measurement includes flatness detection, perpendicularity detection, roundness detection, and runout detection.

6. The manufacturing process for the corrosion-resistant turret friction ring of a deep-sea FSO according to claim 1, characterized in that: The post-weld heat treatment process is as follows: slowly heat to 570±10℃ at a heating rate of <100℃ / h and hold for 4 hours, then slowly cool to below 200℃ at a cooling rate of <100℃ / h and air cool.

7. The manufacturing process for the corrosion-resistant turret friction ring of a deep-sea FSO according to claim 6, characterized in that: During post-weld heat treatment, the furnace should be opened after cooling to 170°C.

8. The manufacturing process for the corrosion-resistant turret friction ring of a deep-sea FSO according to claim 1, characterized in that: The clamping fixture includes a frame and multiple clamping plate modules mounted on the frame. The frame is equipped with a lifting ring for hoisting by a crane. Each clamping plate module includes two clamping plates, which are fixed to each other by bolts, and the two clamping plates are located at opposite ends of the substrate axial direction.

9. The manufacturing process for the corrosion-resistant turret friction ring of a deep-sea FSO according to claim 1, characterized in that: The hoisting fixture includes a support ring and multiple fixing components. The support ring is provided with a second lifting ring, which is used to cooperate with a crane. The support ring is connected to the final formed friction ring through the fixing components. The fixing components include a flange and a stud. The two ends of the stud are respectively fixed relative to the support ring and the base material. The flange is sleeved on the stud. The connection between the flange and the stud is fixed by bolts and nuts.

10. The manufacturing process for the corrosion-resistant turret friction ring of a deep-sea FSO according to claim 9, characterized in that: The stud, support ring, and finally formed friction ring are all fixed by threads.

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