A method for manufacturing a multi-dimensional flow channel profile

Abstract

The application discloses a kind of multi-dimension flow channel special-shaped body manufacturing method, including steps S1: rough machining, rectangular parallelepiped forging is processed into the special-shaped piece of internal multi-dimension flow channel;S2: after rough machining, workpiece is treated, temperature is at 320±10 ℃, keeps warm 4 hours, deep hole processing is carried out to workpiece, and the multi-dimension flow channel special-shaped body ontology is obtained;S3: vibration stress relief treatment is carried out, and multi-dimension flow channel special-shaped body ontology is assembled, including the assembly of multi-dimension flow channel special-shaped body ontology and cover plate, finger;S4: vacuum stress relief heat treatment, temperature is at 400±10 ℃, heating or cooling rate is not more than 55 ℃ / h, and the maximum local temperature difference of part is not more than 55 ℃, then keeps warm 2 hours.The multi-dimension flow channel special-shaped body of the application is assembled and welded after being assembled and welded with the first wall full-size prototype left and right 10 pairs of fingers, and two large circular surfaces are formed, the height difference between adjacent fingers on the whole circular surface is not more than 0.5mm, to meet product requirements.

Description

Technical Field

[0001] This invention relates to the field of first wall component manufacturing technology, and in particular to a method for manufacturing multi-dimensional flow channel irregular shapes. Background Technology

[0002] As a component directly facing the plasma, the first wall must directly withstand the high thermal load and strong neutron wall load from the plasma, and operate under high temperature and pressure. Therefore, the processing and manufacturing requirements for the first wall are quite stringent. Among them, the multi-dimensional flow channel irregular shape is a key component. It is made from a cuboid forging and machined into an irregular shape with internal multi-dimensional flow channels. The machining allowance is large, and poor deformation control will affect subsequent installation and docking.

[0003] For example, the article "ITER TBM First Wall Manufacturing Method and Prototype Production" in the journal "Nuclear Fusion and Plasma Physics" introduces the current processing methods. One method is: bending square plates - milling grooves - laser welding. This method mainly involves bending rectangular steel plates into U-shaped steel plates, milling grooves around the U-shaped steel plates, and then laser welding steel strips onto the rectangular grooves of the steel plates to form rectangular flow channels. Another method is: preparing rectangular tubes - vacuum electron beam sealing welding - hot isostatic pressing welding - bending. Rectangular tubes are placed side by side, clamped together with rectangular plates, and placed in a vacuum electron beam welding device for sealing welding. That is, all gaps between plates and tubes are welded and sealed. Then, they are placed in a hot isostatic pressing furnace, pressurized to about 150 MPa, and held at 1100℃ for 2 hours. The high temperature and high pressure gas is used to completely connect the internal contact surfaces that have not been welded by the electron beam, and then the tubes are bent into shape.

[0004] While the first method is more convenient for single-piece processing research, and bending solid steel plates is easier to control than bending perforated square plates with almost no deformation in the flow channel, its welding and assembly are more complex, involving more welding, making post-weld non-destructive testing more difficult, and the fusion welding may cause embrittlement. Moreover, this method is only applicable to the design of rectangular flow channels. The second method can eliminate the problem of embrittlement of fusion welded joints, but the manufacturing process of square tubes is more complex, requiring more pre-welding machining and cleaning preparation, and is subject to stress, making it prone to deformation when manufacturing curved flow channels. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for manufacturing multi-dimensional flow channel irregular shapes.

[0006] This invention is achieved through the following technical solution:

[0007] A method for manufacturing a multi-dimensional flow channel irregular body includes the following steps:

[0008] S1: Rough machining, which transforms a rectangular forging into a non-circular part with internal multi-dimensional flow channels;

[0009] S2: Stabilize the rough-machined workpiece at 320±10℃ for 3-5 hours, then perform deep hole machining to obtain a multi-dimensional flow channel irregular body.

[0010] S3: Perform vibration stress relief treatment and assemble the multi-dimensional flow channel irregular body, including the assembly of the multi-dimensional flow channel irregular body with the cover plate, fingers and L tube.

[0011] S4: Vacuum stress-relieving heat treatment, temperature at 400±10℃, heating or cooling rate not exceeding 55℃ / h, maximum local temperature difference of parts not exceeding 55℃, then hold for 1-3 hours.

[0012] The deep hole machining of the workpiece specifically includes:

[0013] The location and size of the deep holes are determined according to the type, number, and actual dimensions required.

[0014] Deep holes are machined by drilling at both ends and joining them in the middle.

[0015] The deep hole measurement includes:

[0016] A special gauge is used to check the size of the deep hole. This gauge can slide freely inside the hole by its own weight. A special measuring tool is used to measure the hole depth, and a self-made measuring rod is used to check the straightness of the deep hole.

[0017] The assembly of the multi-dimensional flow channel irregular body and the finger specifically includes:

[0018] Fingers are installed on both sides of the multi-dimensional flow channel irregular body to ensure the surface profile of the beryllium surface of the fingers.

[0019] The assembly of the multi-dimensional flow channel irregular body and cover plate specifically includes:

[0020] Measure the actual dimensions of the multi-dimensional flow channel irregular body and the cover plate mating point, record the numbers, and make the cover plate according to the measured dimensions to ensure the accuracy of the cover plate mating surface clearance.

[0021] The cover plate has rounded corners at its four corners, and is welded to the surface of the multi-dimensional flow channel body.

[0022] After the multi-dimensional flow channel irregular body is welded to the cover plate, the machining reference surface of the multi-dimensional flow channel irregular body is determined.

[0023] Specialized tooling is used to assemble and weld the L-tube to the nozzle of the multi-dimensional flow channel.

[0024] The beneficial effects of this invention are as follows: This invention eliminates the stress experienced by the multi-dimensional flow channel irregular body during the production process through stabilization treatment and vacuum stress-relieving heat treatment, resulting in small deformation during manufacturing and assembly, thus ensuring the quality of flow channel forming; the assembly mating surface is completed through one clamping and positioning machining, and the machining reference surface is redefined, ensuring the machining accuracy requirements of the mating surface after welding of the multi-dimensional flow channel irregular body; after the multi-dimensional flow channel irregular body of this invention is assembled and welded with the left and right 10 pairs of fingers of the full-size prototype of the first wall, two large arc surfaces are formed, and the height difference between adjacent fingers on the entire arc surface does not exceed 0.5mm, which meets the product requirements. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating the present invention;

[0026] Figure 2 This is a schematic diagram of the machining reference for the finger mounting part of the present invention;

[0027] Figure 3 This is a schematic diagram of the L-tube installation of the present invention;

[0028] Figure 4 This is a schematic diagram of the internal groove detection of the present invention. Detailed Implementation

[0029] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0030] The multi-dimensional flow channel irregular body has a large machining allowance, and the austenitic material used has a large residual stress from machining. The amount of deformation will affect the subsequent installation and docking with the finger. In order to ensure the dimensional accuracy of the finished product, better docking with the finger, and small long-term stress release deformation after machining, the machining process should be divided into roughing, semi-finishing and finishing processes. After roughing, stabilization treatment is performed to eliminate the residual stress of the product. After semi-finishing, vibration stress relief treatment is performed to eliminate the deformation caused by machining deep holes. Before finishing, vacuum stress relief heat treatment is performed, and the state before stress relief is as close as possible to the finished product size to prevent deformation caused by stress redistribution after the allowance is removed.

[0031] The present invention proposes a method for manufacturing multi-dimensional flow channel irregular shapes, comprising the following steps:

[0032] S1: Rough machining, which transforms a rectangular forging into a non-circular part with internal multi-dimensional flow channels;

[0033] S2: Stabilize the rough-machined workpiece at 320±10℃ for 4 hours, then perform deep hole machining on the workpiece to obtain a multi-dimensional flow channel irregular body.

[0034] S3: Perform vibration stress relief treatment and assemble the multi-dimensional flow channel irregular body, including the assembly of the multi-dimensional flow channel irregular body with the cover plate and fingers;

[0035] S4: Vacuum stress relief heat treatment, temperature at 400±10℃, heating or cooling rate not exceeding 55℃ / h, maximum local temperature difference of parts not exceeding 55℃, then hold at the temperature for 2 hours.

[0036] The multi-dimensional flow channel profile contains flow channel holes at various spatial locations, with a maximum diameter of 40mm, a minimum diameter of 12mm, and a depth of up to 1000mm. The spatial positions of these holes are highly variable. When machining these deep holes, it is necessary to ensure the positional accuracy and straightness of the hole outlet, while simultaneously inspecting the hole diameter and straightness. Therefore, before machining, the specific parameters of the required deep holes, including their type, quantity, and actual dimensions, must be determined. The tool structure must then be selected, including the tool rotation speed, feed rate, and the guide length of the extended gun drill.

[0037] For through holes, the preferred processing method is to drill at both ends and connect them within a multi-dimensional flow channel profile, which can effectively improve the straightness of deep holes. When measuring deep holes, a special gauge is used to check the size of the hole. The gauge can slide freely inside the hole and can check the diameter of holes at different depths.

[0038] like Figure 2 As shown, fingers are installed on the central beam of the multi-dimensional flow channel body. Every 10 pairs of fingers are assembled on the same side of the central beam, such as the dovetail groove, to ensure the surface profile of the beryllium surface of the fingers and the consistent gap between the sides of the fingers.

[0039] To prevent large or uneven gaps between the cover plate and the multi-dimensional flow channel shape, which could lead to splashes inside the multi-dimensional flow channel shape that are difficult to remove and affect the normal use of the product, the fit gap between the cover plate and the multi-dimensional flow channel shape must be less than 0.05mm. The four corners of the cover plate are rounded with R-angles. The cover plate is welded to the surface of the multi-dimensional flow channel shape body. After welding, helium leak testing is required.

[0040] To ensure the accuracy requirements of the gap between the cover plate mating surfaces, the actual dimensions of the multi-dimensional flow channel irregular body and the cover plate mating area are measured, numbered and recorded, and the cover plate is made according to the measured dimensions.

[0041] like Figure 2As shown, after welding the multi-dimensional flow channel body to the cover plate and the copper cladding for electrical connection, it is necessary to complete the machining of the finger assembly surface and threaded holes. Since the multi-dimensional flow channel body is made of 316LN stainless steel, which has a low thermal conductivity and a high coefficient of linear expansion, the residence time of the weld metal in the high-temperature zone is prolonged, thus increasing the tensile strain of the weld at high temperatures and causing greater deformation. Therefore, it is necessary to determine the machining reference surface of the multi-dimensional flow channel body, unify the machining reference with the design reference, machine the dovetail groove, and use a four-axis gantry machining center for one-time clamping and positioning to complete the machining of the assembly surface.

[0042] like Figure 3 As shown, when assembling and welding the nozzle of the multi-dimensional flow channel irregular body with L-tube 7, it is difficult to assemble all L-tube 7s uniformly. Even a slight deviation in the arc starting point of the weld will cause inconsistency in the pipe openings. Assembly gaps and misalignments also have a significant impact. The other end of L-tube 7 deflects, affecting subsequent mating and assembly with the finger. Therefore, a special assembly fixture is designed. This fixture uses the outer circular surface of the L-tube 7 and the connecting pipe of the multi-dimensional flow channel irregular body as the fixture positioning surface. The adjusting shaft 4 is used to adjust the outer circle of the nozzle of L-tube 7 and the outer circle of the connecting pipe of the multi-dimensional flow channel irregular body to be basically aligned. Then, the positioning pin 2 is inserted into the upper pipe opening of L-tube to ensure the perpendicularity of L-tube and multi-dimensional flow channel irregular body. Then, the adjusting bolt 3 is used to fine-tune L-tube to ensure that the pipe opening of L-tube 7 is aligned with the pipe opening of the connecting pipe of the multi-dimensional flow channel irregular body, ensuring that the assembly gap and misalignment are no more than 0.05mm, meeting the pipe-to-pipe welding requirements. After spot welding, the fixture is removed and welding is performed.

[0043] To ensure the welding quality of the L-tube and the nozzle of the multi-dimensional flow channel, a test weld is performed using a test tube before welding. The welding torch is placed at the welding point, the tungsten electrode is aligned with the weld seam, the tungsten electrode is adjusted to the determined arc starting point, and the welding point is clamped. The pipe is then vented for 50 seconds for protection, and the flow rate of the protective gas is controlled. After observing that all conditions are normal, the welding switch is turned on for welding, while ensuring that the arc starting point of the weld seam is consistent. After welding, the weld seam is subjected to visual inspection, non-destructive testing, pressure test, and thermal fatigue test. The weld formation is then observed, and any defects such as incomplete penetration or cracks require rework.

[0044] like Figure 4 As shown, the multi-dimensional flow channel irregular body pipe connection mechanism has a complex structure and high precision requirements, which are difficult to guarantee using conventional measurements during processing. In the machining of multi-dimensional flow channel irregular bodies, the dimension inspection of the grooves inside the holes is difficult to meet the requirements using conventional depth vernier calipers due to the small hole size. Therefore, using a dedicated depth caliper to measure the width and axial position of the internal grooves can be applied to grooves of different shapes and sizes.

[0045] After the multi-dimensional flow channel irregular body is processed, the product accuracy meets the assembly requirements through three-coordinate inspection. After the multi-dimensional flow channel irregular body is assembled with the full-size prototype of the first wall, the ten pairs of fingers on each side of the full-size prototype of the first wall and the multi-dimensional flow channel irregular body form two large arc surfaces. The height difference between adjacent fingers on the entire arc surface does not exceed 0.5mm, the gap between fingers is within 1mm to 1.8mm, and the front-to-back difference is not greater than 0.5mm.

Claims

1. A method for manufacturing a multi-dimensional flow channel irregular body, characterized in that, Includes the following steps: S1: Rough machining, which transforms a rectangular forging into a non-circular part with internal multi-dimensional flow channels; S2: Stabilize the rough-machined workpiece at 320±10℃ for 3-5 hours, then perform deep hole machining to obtain a multi-dimensional flow channel irregular body. S3: Perform vibration stress relief treatment and assemble the multi-dimensional flow channel irregular body, including the assembly of the multi-dimensional flow channel irregular body with the cover plate, fingers and L tube. S4: Vacuum stress-relieving heat treatment, temperature at 400±10℃, heating or cooling rate not exceeding 55℃ / h, maximum local temperature difference of parts not exceeding 55℃, then hold for 1-3 hours.

2. The method for manufacturing a multi-dimensional flow channel irregular body according to claim 1, characterized in that, The deep hole machining of the workpiece specifically includes: The location and size of the deep holes are determined according to the type, number, and actual dimensions required. Deep holes are machined by drilling at both ends and joining them in the middle.

3. The method for manufacturing a multi-dimensional flow channel irregular body according to claim 2, characterized in that, Deep hole measurements include: A special gauge is used to check the size of the deep hole. This gauge can slide freely inside the hole by its own weight. A special measuring tool is used to measure the hole depth, and a self-made measuring rod is used to check the straightness of the deep hole.

4. The method for manufacturing a multi-dimensional flow channel irregular body according to claim 1, characterized in that, The assembly of the multi-dimensional flow channel irregular body and the finger specifically includes: Fingers are installed on both sides of the multi-dimensional flow channel irregular body to ensure the surface profile of the beryllium surface of the fingers.

5. The method for manufacturing a multi-dimensional flow channel irregular body according to claim 1, characterized in that, The assembly of the multi-dimensional flow channel irregular body and cover plate specifically includes: Measure the actual dimensions of the multi-dimensional flow channel irregular body and the cover plate mating point, record the numbers, and make the cover plate according to the measured dimensions to ensure the accuracy of the cover plate mating surface clearance. The cover plate has rounded corners at its four corners, and is welded to the surface of the multi-dimensional flow channel body.

6. The method for manufacturing a multi-dimensional flow channel irregular body according to claim 5, characterized in that, After the multi-dimensional flow channel irregular body is welded to the cover plate, the machining reference surface of the multi-dimensional flow channel irregular body is determined.

7. The method for manufacturing a multi-dimensional flow channel irregular body according to claim 1, characterized in that, The L-tube is assembled and welded with the nozzle of the multi-dimensional flow channel irregular body.

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