A manufacturing method for a large opening angle section of austenitic stainless steel

Abstract

The present application provides a method for manufacturing a large opening angle section of austenitic stainless steel, including: dividing the shell into multiple identical segmented shells and performing unfolding and lofting, cutting the material, preparing the bevel and pressing into shape for each segmented shell; designing the profile tooling; assembling the profile tooling; assembling and welding the segmented shells: the large opening angle section shell is vertically assembled layer by layer starting from the outlet, first assembling the segmented shell at the outlet, and then assembling other segmented shells layer by layer until the assembly is completed, and finally spot welding the segmented shell to the profile tooling; after welding the entire shell part, assembling and completing the welding of the stiffeners; measuring the projection length of the entire shell in the central axis direction, measuring the inner circumferences at the inlet and outlet of the entire shell, cutting the forming allowances reserved at the inlet and outlet of the entire shell, and finally installing and welding the flanges. This method can effectively ensure the final profile accuracy of the large opening angle section by innovating the processes of lofting and forming the segmented shell, shell assembly, and shell welding.

Description

Technical Field

[0001] This application relates to the field of wind tunnels, and particularly to a manufacturing method for a large opening angle section of austenitic stainless steel. Background Art

[0002] With the adoption of a large contraction ratio in wind tunnels and the requirement to minimize the size of the upstream pipeline in the settling chamber as much as possible, a large opening angle section needs to be configured at the inlet of the settling chamber of the wind tunnel. Its function is to achieve area expansion within a short distance, reduce the outlet air flow velocity and increase the static pressure, thereby reducing the length of the wind tunnel circuit, as well as the construction cost and operating cost. The expansion angle of the large opening angle section of a conventional wind tunnel is usually designed to be 30 - 90°, and it is made of a conical shell. To reduce air flow separation and pressure loss, under cryogenic conditions, the operating temperature of the wind tunnel is extremely low, close to -196°C. The large opening angle section is made of austenitic stainless steel, and the shell is designed as a hyperbolic shell to improve the flow field quality in the test section.

[0003] The large opening angle section of austenitic stainless steel consists of a shell, stiffeners, and flanges. It belongs to a non-pressure-bearing internal section and is installed in the plenum chamber. The shell thickness is relatively thin, and there are three technical difficulties in its manufacturing. First, the shell is a hyperbolic surface with high surface requirements, and it is difficult to meet the accuracy requirements using traditional methods for assembly. Second, during the assembly process of the shell, when precisely aligning the austenitic stainless steel surface, flame trimming cannot be used, resulting in low assembly efficiency. Third, the shell thickness is relatively thin, and the welding deformation of austenitic stainless steel is large, causing serious deformation of the shell after welding, making it difficult to ensure the final surface accuracy and unable to meet the design and aerodynamic surface requirements. Summary of the Invention

[0004] This application provides a manufacturing method for a large opening angle section of austenitic stainless steel, aiming to solve the problem of low surface accuracy in the manufacturing of the shell of the large opening angle section in existing wind tunnels.

[0005] The technical solution of this application is as follows:

[0006] A manufacturing method for a large opening angle section of austenitic stainless steel can effectively ensure the final surface accuracy of the large opening angle section by innovating the shell sectional lofting and forming process, the shell assembly process, and the shell welding process. The method mainly includes the following steps:

[0007] S1, Shell forming: According to the dimensions of the large-opening-angle section of the wind tunnel and the processing capacity of the three-dimensional numerical control bending machine, the circumferential side wall of the integral shell of the large-opening-angle section is divided into multiple layers of stratified shells along the height direction, and the circumferential side wall of each layer of the stratified shell is equally spaced into multiple segmented shells along the circumferential direction, and the number of the segmented shells in each layer is the same; accurately develop and lay out each of the segmented shells to obtain a developed layout drawing; cut the material for each of the segmented shells according to the developed layout drawing, and reserve a forming allowance on the outer contour of the multiple segmented shells during material cutting; use a beveling machine to prepare bevels for the segmented shells, use the three-dimensional numerical control bending machine to press and form the segmented shells, and use a template to check the surface accuracy of the segmented shells after forming, and use a hydraulic press to perform spot pressing and straightening on the local positions where the surface accuracy of the segmented shells does not meet the requirements;

[0008] S2, Design a corresponding surface tooling according to the dimensions of the large-opening-angle section: The surface tooling is composed of multiple surface ribs, multiple layers of circumferential ribs, multiple layers of cross braces, and a lifting support; the outer end faces of the multiple surface ribs in the width direction are attached to the inner surface of the integral shell and are circumferentially spaced around the central axis of the integral shell, and the number of the surface ribs is the same as the number of the segmented shells on each layer of the stratified shell; the multiple layers of circumferential ribs are all in a circular ring structure and are arranged in parallel at intervals around the central axis of the integral shell, and on the upper surface and the lower surface in the thickness direction, they are arranged along the direction perpendicular to the central axis of the integral shell, and the multiple layers of circumferential ribs are spaced from the entrance to the exit of the integral shell along the central axis of the integral shell, and the outer end face of the circumferential rib in the width direction is attached to the inner surface of the integral shell; the lifting support is arranged in a direction perpendicular to the central axis of the integral shell and is in the middle of the cavity surrounded by the multiple layers of circumferential ribs, and the respective angular ends in the circumferential direction are respectively connected to the circumferential ribs at the middle part; the multiple layers of cross braces are arranged in parallel at intervals in sequence in the cavity along the direction perpendicular to the central axis of the integral shell, the lifting support is between the two adjacent cross braces above and below, and the respective angular ends in the circumferential direction of each cross brace are respectively connected to the corresponding circumferential ribs;

[0009] S3, Vertically assemble the surface tooling: The axis of the surface tooling is perpendicular to the ground horizontal plane. First, assemble the circumferential rib at the exit of the large-opening-angle section on the steel plate platform, adjust the elevations of the upper surfaces of the circumferential ribs at the exit of the large-opening-angle section to the same height and assemble the cross braces, then assemble the surface ribs on the circumferential rib at the exit of the large-opening-angle section, and then sequentially assemble the other layers of circumferential ribs, cross braces, and lifting supports layer by layer in the direction away from the exit of the large-opening-angle section until the assembly is completed, and finally reinforce and weld the surface tooling;

[0010] S4. Vertically assemble and weld the segmented shells layer by layer in the direction from the outlet of the large opening angle section towards the inlet: First, assemble the segmented shells at the outlet of the large opening angle section. Fit the inner surface of the segmented shell to the outer end surface of the profile rib in the width direction and assemble them. After assembly, adjust the misalignment amount to make the central axis of this layer of segmented shell collinear with the central axis of the profile tooling. Use the same method to sequentially assemble the segmented shells of other layers layer by layer in the direction away from the outlet of the large opening angle section until the assembly is completed. Finally, tack-weld each segmented shell to the profile tooling. Weld the segmented shells using tungsten inert gas welding. First, perform back welding on the segmented shells, then fill and cover the groove on the inner wall of the segmented shells with welding, then install anti-deformation longitudinal ribs along the longitudinal welds on the inner wall of the segmented shells, and install anti-deformation circumferential ribs along the circumferential welds on the inner wall of the segmented shells. Finally, fill and cover the groove on the outer wall of the segmented shells with welding.

[0011] S5. Cut and install the assembled integral shell: After welding the multi-layer segmented shells, assemble and weld the reinforcing ribs to form the integral shell. Measure the projected length of the integral shell in the central axis direction, and measure the inner circumferences of the integral shell at the inlet and outlet respectively. According to the design dimensions of the large opening angle section combined with the measured data, cut the forming allowances reserved at the inlet and outlet of the integral shell, and finally install and weld the flanges on the integral shell.

[0012] As a technical solution of the present application, in step S1, for the segmented shells of this layer at the inlet position of the large opening angle section, on the inlet ends and both side ends of the outer contours of any two selected segmented shells, 10 - 20 mm of forming allowances are respectively reserved, and no forming allowance is reserved at the lower end. For the remaining segmented shells, only 10 - 20 mm of forming allowances are respectively reserved on the inlet ends of their outer contours, and no forming allowance is reserved at the non-inlet ends. For the segmented shells of this layer at the outlet position of the large opening angle section, on the outlet ends and both side ends of the outer contours of any two selected segmented shells, 10 - 20 mm of forming allowances are respectively reserved, and no forming allowance is reserved at the upper end. For the remaining segmented shells, 10 - 20 mm of forming allowances are respectively reserved on the outlet ends of their outer contours, and no forming allowance is reserved at the non-outlet ends. For the segmented shells at other positions of the large opening angle section, on both side ends of the outer contours of any two selected segmented shells, 10 - 20 mm of forming allowances are respectively reserved, and no forming allowances are reserved at the upper and lower ends. For the remaining segmented shells, no forming allowances are reserved on their outer contours.

[0013] As a technical solution of the present application, in step S1, after blanking the plurality of segmented shells, a bevel is prepared at the port of the segmented shell without reserved forming allowance by using the beveling machine, and the bevel is an X-shaped symmetric bevel.

[0014] As a technical solution of the present application, in step S2, the projection length of the profile rib in the central axis direction is the same as that of the integral shell; the size of the ring formed by enclosing multiple circumferential ribs gradually increases from the inlet to the outlet direction of the integral shell, and the distance between adjacent circumferential ribs is 500-800 mm. The circumferential rib at the outlet of the large opening angle section is an integral ring plate, and multiple profile ribs are installed at intervals on the upper surface. Each circumferential rib at the remaining positions of the large opening angle section is a segmented ring plate and is penetrated by the corresponding profile ribs of each layer.

[0015] As a technical solution of the present application, in step S2, the hoisting support is made of multiple H-shaped steels and is installed at the middle position of the profile tooling in the central axis direction of the integral shell; a lifting lug is installed on the hoisting support, and the surrounding of the installation position of the lifting lug is strengthened by profiles for the hoisting support. The large opening angle section can be hoisted with overall micro-deformation through the hoisting support;

[0016] As a technical solution of the present application, in step S4, when assembling the segmented shell at the outlet of the large opening angle section, first assemble the segmented shell with a forming allowance of 10-20 mm reserved at the outlet end of the outer contour, and then assemble the segmented shell with a forming allowance of 10-20 mm reserved at both the outlet end and the two side ends of the outer contour. The last two assembled segmented shells are symmetric about the central axis of the integral shell; when assembling the segmented shell at the inlet of the large opening angle section, first assemble the segmented shell with a forming allowance of 10-20 mm reserved at the inlet end of the outer contour, and then assemble two segmented shells with a forming allowance of 10-20 mm reserved at both the inlet end and the two side ends of the outer contour. The last two assembled segmented shells are symmetric about the central axis of the integral shell; when assembling each layer of segmented shell at other positions of the large opening angle section, first assemble the segmented shell without forming allowance on the outer contour, and then assemble two segmented shells with a forming allowance of 10-20 mm reserved at both side ends of the outer contour. The last two assembled segmented shells are symmetric about the central axis of the integral shell.

[0017] As a technical solution of the present application, in step S4, before assembling the segmented shell with a forming allowance of 10-20 mm at the outlet end and both side ends of the outer contour, first use a grinding wheel to cut and trim both side ends of the segmented shell; before assembling the segmented shell with a forming allowance of 10-20 mm at the inlet end and both side ends of the outer contour, first use a grinding wheel to cut and trim both side ends of the segmented shell; before assembling the segmented shell with a forming allowance of 10-20 mm at both side ends of the outer contour, first use a grinding wheel to cut and trim both side ends of the segmented shell.

[0018] As a technical solution of the present application, in step S4, each longitudinal weld on the inner wall of the segmented shell is correspondingly installed with the anti-deformation longitudinal bars. The outer end surface of the anti-deformation longitudinal bars in the width direction fits with the inner surface of the segmented shell at the longitudinal weld, and the top and bottom ends of the anti-deformation longitudinal bars are respectively vertically welded between two adjacent circumferential ribs; each circumferential weld on the inner wall of the segmented shell is correspondingly installed with the anti-deformation circumferential bars. The outer end surface of the anti-deformation circumferential bars in the width direction fits with the inner surface of the segmented shell at the circumferential weld, and the two ends of the anti-deformation circumferential bars are respectively vertically welded between two adjacent profile steel plates.

[0019] As a technical solution of the present application, in step S5, the inlet of the integral shell is cut by a plasma cutting machine, and the outlet of the integral shell is cut by a grinding wheel.

[0020] Advantages of the present application:

[0021] The present application provides a method for manufacturing a large-opening angle section of austenitic stainless steel. By accurately developing and laying out the segmented shell, most of the outer contours of the segmented shell do not need to reserve forming allowances. After blanking, the bevel can be directly prepared. When assembling, there is no need to repair the outer contour and then prepare the bevel, which can greatly improve the assembling efficiency and simplify the assembling difficulty. At the same time, this method simplifies the assembling difficulty and improves the assembling accuracy by designing a profile tooling to assist in the assembling of the segmented shell, and is applicable to the assembling of all hyperbolic shells. Moreover, the profile tooling is designed with a lifting support, which can greatly reduce the deformation during the lifting, turning over and installation of the large-opening angle section, thereby further ensuring the profile accuracy. In addition, this method first welds the inner wall welds of the shell, then installs the anti-deformation longitudinal bars and anti-deformation circumferential bars, and finally welds the outer wall welds of the shell. Using this welding process greatly reduces the shrinkage during the shell welding process and the depression deformation at the welds, ensuring the profile accuracy of the large-opening angle section after welding. Furthermore, this method reserves forming allowances at both the inlet and outlet of the segmented shell. After the segmented shell is formed, it is not cut. After the shell is welded and inspected, the allowances at the inlet and outlet of the shell are cut as a whole, which not only improves the assembling efficiency but also ensures the final dimensional accuracy of the large-opening angle section. Brief Description of the Drawings

[0022] To more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 Structural schematic diagram of the large opening angle section provided by the embodiment of the present application;

[0024] Figure 2 Schematic diagram of the segmented division of the entire housing provided by the embodiment of the present application;

[0025] Figure 3 Schematic diagram of the developed pattern of the first-layer segmented housing provided by the embodiment of the present application;

[0026] Figure 4 Schematic diagram of the developed pattern of the second-layer segmented housing provided by the embodiment of the present application;

[0027] Figure 5 Schematic diagram of the profile tooling structure provided by the embodiment of the present application;

[0028] Figure 6 Schematic diagram of the first process of assembling the segmented housing provided by the embodiment of the present application;

[0029] Figure 7 Schematic diagram of the second process of assembling the segmented housing provided by the embodiment of the present application;

[0030] Figure 8 Schematic diagram of the installation of the anti-deformation longitudinal bars and anti-deformation hoop bars provided by the embodiment of the present application.

[0031] Reference Signs: 1 - large opening angle section; 2 - flange; 3 - entire housing; 4 - reinforcing rib; 5 - segmented housing; 6 - longitudinal weld; 7 - circumferential weld; 8 - steel plate platform; 9 - profile tooling; 10 - profile surface rib; 11 - circumferential rib; 12 - cross brace; 13 - profile; 14 - lifting support; 15 - anti-deformation longitudinal bar; 16 - anti-deformation hoop bar. Detailed Embodiments

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0033] Accordingly, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0034] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not require further definition and explanation in subsequent drawings.

[0035] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present application.

[0036] In addition, in the present application, unless otherwise clearly specified and limited, the first feature being above or below the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through additional features therebetween. Moreover, the first feature being above, over, and on the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being below, under, and beneath the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0037] In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or hanging, but may be slightly inclined. For example, "horizontal" merely means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but may be slightly inclined.

[0038] In the description of the present application, it should also be noted that unless otherwise clearly specified and limited, the terms "arranged", "connected", and "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0039] Embodiment:

[0040] The solution of this embodiment is aimed at subjects such as Figure 1 As shown, it is an austenitic stainless steel large open angle section 1, the inlet size is φ6800mm, the outlet size is 10500mm, and the front and rear end axis length is 4500mm. The large open angle section 1 is composed of a flange 2, a whole shell 3 and a reinforcing rib 4. The thickness of the whole shell 3 is 16mm and the material is S30403.

[0041] like Figures 2 to 4 As shown, according to the size of the large open angle section 1 and the processing capacity of the three-dimensional CNC plate bending machine, the entire shell 3 is divided into two layers of layered shells, the first layer of shells near the exit and the second layer of shells near the entrance. Both layers of layered shells are divided into 14 identical segmented shells 5. The segmented shells 5 are accurately unfolded and sampled to obtain the first layer of shell segment unfolding sample drawing. Figure 3 And the second shell segmented layout Figure 4 . Cut the first layer of segmented shells 5 and the second layer of segmented shells 5 respectively according to the unfolded sample drawing. When cutting, a forming allowance is reserved on the outer contour of some segmented shells 5, as follows: for the second layer of segmented shells 5, the outer contours of two segmented shells 5 have a forming allowance of 10 to 20 mm at the inlet end and both side ends, respectively, and no forming allowance is reserved at the lower end. The outer contours of the remaining 12 segmented shells 5 only have a forming allowance of 10 to 20 mm at the inlet end, and no forming allowance is reserved at the non-inlet end; for the first layer of segmented shells 5, the outer contours of two segmented shells 5 have a forming allowance of 10 to 20 mm at the outlet end and both side ends, respectively, and no forming allowance is reserved at the upper end. The outer contours of the remaining 12 segmented shells 5 only have a forming allowance of 10 to 20 mm at the outlet end, and no forming allowance is reserved at the non-outlet end.

[0042] A beveling machine is used to prepare bevels for the cut segmented shell 5. Bevels are prepared only at ports without reserved forming margins. The bevel form is an X-shaped symmetrical bevel with a bevel angle of 50°. No bevels are prepared at ports with reserved forming margins. A three-dimensional CNC plate bending machine is used to press and form 28 segmented shells 5. After forming, a sample is used to check the surface accuracy of the segmented shell 5. A hydraulic press is used to perform point pressure correction on the local positions where the surface accuracy does not meet the requirements.

[0043] like Figure 5As shown in the figure, a corresponding profile tooling 9 is designed according to the size of the large opening angle section 1: The profile tooling 9 is jointly composed of a profile rib 10, a circumferential rib 11, a cross brace 12, and a lifting support 14. The outer end surface of the profile rib 10 in the width direction is completely fitted with the inner profile of the integral housing 3. It is evenly distributed circumferentially around the central axis of the integral housing 3, with a quantity of 14. The axial length of the front and rear ends of the profile rib 10 is 4500 mm. The circumferential rib 11 is a multi-layer circular ring structure. Its upper surface and lower surface in the thickness direction are both arranged along the direction perpendicular to the central axis of the integral housing 3, and are discontinuously distributed along the central axis of the integral housing 3 from the inlet to the outlet of the integral housing 3. The outer end surface of the circumferential rib 11 in the width direction is completely fitted with the inner profile of the integral housing 3. The size of the circular ring formed by the circumferential rib 11 gradually increases from the inlet to the outlet of the integral housing 3. The distance between adjacent circumferential ribs 11 is 500 - 800 mm. The circumferential rib 11 at the outlet of the large opening angle section 1 is an integral circular ring plate, and a plurality of spaced profile ribs 10 are installed on its upper surface. Each layer of the circumferential rib 11 at the remaining positions of the large opening angle section 1 is a disconnected segmented circular ring plate and is vertically penetrated by the corresponding profile ribs 10 of each layer.

[0044] As Figure 5 shown, the lifting support 14 is made of an H-shaped steel with a size of 300×300. It is arranged along the direction perpendicular to the central axis of the integral housing 3 and is installed at the middle position of the profile tooling 9 in the axial direction. It is in the middle of the cavity jointly formed by multiple layers of circumferential ribs 11, and each angular end in the circumferential direction is respectively connected to the circumferential rib 11 at the middle position. A lifting lug is provided on the lifting support 14, and the profile 13 is used to strengthen the stiffness of the lifting support 14 around the installation position of the lifting lug. Through the lifting support 14, the large opening angle section 1 can be lifted with overall micro-deformation. The cross brace 12 is a multi-layer structure. Multiple layers of cross braces 12 are sequentially arranged in parallel at intervals along the direction perpendicular to the central axis of the integral housing 3 in the cavity, and are respectively spaced above the upper surface and below the lower surface of the lifting support 14, and each angular end in the circumferential direction of each cross brace 12 is respectively connected to the corresponding circumferential rib 11.

[0045] As Figure 5 shown, before assembling the integral housing 3 of the large opening angle section 1, first manufacture the profile tooling 9. The profile tooling 9 is assembled vertically with its axis perpendicular to the ground horizontal plane. First, assemble the circumferential rib 11 at the outlet of the large opening angle section 1 on the steel plate platform 8, adjust the elevation of the upper surface of the circumferential rib 11 at the outlet of the large opening angle section 1 to the same height and assemble the cross brace 12, then assemble the profile rib 10 on the circumferential rib 11 at the outlet of the large opening angle section 1, and then sequentially assemble the circumferential rib 11, the cross brace 12, and the lifting support 14 layer by layer in the direction away from the outlet of the large opening angle section 1 until the assembly is completed. Finally, strengthen and weld the profile tooling 9.

[0046] As Figures 6 to 7As shown in the figure, after the profile tooling 9 is manufactured, the segmented shell 5 is assembled and welded. The integral shell 3 of the large opening angle section 1 is vertically assembled layer by layer starting from the outlet, and its central axis is perpendicular to the earth's horizontal plane. First, assemble the segmented shell 5 of the first layer, making the inner profile of the segmented shell 5 fit the outer end face of the profile rib 10 in the width direction for assembly. After the assembly of the segmented shell 5 of the first layer is completed, adjust the misalignment amount and make the shell axis of this layer collinear with the central axis of the profile tooling 9. Use the same method to assemble the segmented shell 5 of the second layer until the assembly is completed, and finally spot weld the segmented shell 5 and the profile tooling 9. When assembling the segmented shell 5 of the first layer, first assemble 12 segmented shells 5 with a forming allowance of only 10 - 20 mm reserved at the outlet end for the outer contour, and finally assemble two segmented shells 5 with a forming allowance of 10 - 20 mm reserved at the outlet end and the left and right side ends for the outer contour of the segmented shell 5. Use a grinding wheel to cut and trim the left and right side ends of the segmented shell 5, and the two finally assembled segmented shells 5 are symmetric about the central axis; when assembling the segmented shell 5 of the second layer, first assemble 12 segmented shells 5 with a forming allowance of only 10 - 20 mm reserved at the inlet end for the outer contour, and finally assemble two segmented shells 5 with a forming allowance of 10 - 20 mm reserved at the inlet end and the left and right side ends for the outer contour of the segmented shell 5. Use a grinding wheel to cut and trim the left and right side ends of the segmented shell 5, and the two finally assembled segmented shells 5 are symmetric about the central axis.

[0047] As Figure 8 shown, the integral shell 3 is welded using tungsten inert gas welding. First, perform root welding, then complete the filling and surfacing welding of the groove on the inner wall of the integral shell 3, then install the anti-deformation longitudinal ribs 15 along the longitudinal weld 6 on the inner wall of the integral shell 3, install the anti-deformation circumferential ribs 16 along the circumferential weld 7 on the inner wall of the integral shell 3, and finally complete the filling and surfacing welding of the groove on the outer wall of the integral shell 3. There are 28 longitudinal welds 6 on the inner wall of the integral shell 3, and the anti-deformation longitudinal ribs 15 are correspondingly installed. The outer end face of the anti-deformation longitudinal rib 15 in the width direction is completely fitted with the inner profile of the integral shell 3 at the longitudinal weld 6. The anti-deformation longitudinal rib 15 is installed between adjacent circumferential ribs 11, and the upper and lower ends of the anti-deformation longitudinal rib 15 are respectively vertically welded to the corresponding circumferential ribs 11. There are anti-deformation circumferential ribs 16 correspondingly installed on the circumferential weld 7 on the inner wall of the integral shell 3. The outer end face of the anti-deformation circumferential rib 16 in the width direction is completely fitted with the inner profile of the integral shell 3 at the circumferential weld 7. The anti-deformation circumferential rib 16 is installed between adjacent profile ribs 10, and the left and right ends of the anti-deformation circumferential rib 16 are respectively vertically welded to the profile ribs 10.

[0048] After the welding of the integral housing 3 is completed, the stiffeners 4 are assembled and welded. Measure the projected length of the integral housing 3 in the axial direction, and measure the inner circumferences at the inlet and outlet of the integral housing 3. According to the design dimensions of the large opening angle section 1 and the measured data, cut the forming allowances reserved at the inlet and outlet of the integral housing 3. The plasma cutter is used for cutting the inlet of the integral housing 3, and the grinding wheel is used for cutting the outlet of the integral housing 3. After cutting, grind the inlet and outlet clean, and finally install and weld the flange 2, thus completing the production of the large opening angle section 1.

[0049] In summary, the present application provides a method for manufacturing an austenitic stainless steel large opening angle section. By accurately developing and laying out the segmented housing 5, there is no need to reserve forming allowances for the outer contours of most of the segmented housing 5. After blanking, the bevel can be directly prepared, and there is no need to repair the outer contour and then prepare the bevel during assembly, which can greatly improve the assembly efficiency and simplify the assembly difficulty. At the same time, this method uses the profile tooling 9 to assist in the assembly of the segmented housing 5, which can greatly simplify the assembly difficulty and improve the assembly accuracy, and is applicable to the assembly of all hyperbolic shells. Moreover, the profile tooling 9 is designed with a lifting support 14, which can greatly reduce the deformation during the lifting, turning over and installation of the large opening angle section 1, thereby further ensuring the profile accuracy. In addition, in this method, the inner wall welds of the housing are welded first, then the anti-deformation longitudinal bars 15 and anti-deformation ring bars 16 are installed, and finally the outer wall welds of the housing are welded. Using this welding process greatly reduces the shrinkage during the housing welding process and the concave deformation at the weld, ensuring the profile accuracy of the large opening angle section 1 after welding. Furthermore, in this method, forming allowances are reserved at both the inlet and outlet of the segmented housing 5. After the segmented housing 5 is formed, it is not cut, and the allowances at the inlet and outlet of the housing are cut as a whole after the housing welding is completed and inspected, which not only improves the assembly efficiency, but also ensures the final dimensional accuracy of the large opening angle section 1. In addition, it adopts a hyperbolic shell forming technology with accurate development and layout without reserving forming allowances, which solves the problems of low assembly efficiency and large assembly difficulty caused by the need for comparison and repair and then preparation of the bevel during the assembly of hyperbolic shells. At the same time, it adopts a welding process of step-by-step welding and installing profile stiffeners 4 on the inner surface of the weld to increase the stiffness at the weld, which solves the problems of large shrinkage during the welding of large thin-walled hyperbolic shells and the inner concave at the weld during the welding of the outer wall bevel, resulting in low profile accuracy after welding. Moreover, it adopts a manufacturing technology of reserving allowances at the inlet and outlet of the segmented housing and cutting the outlet and inlet as a whole after forming, which solves the problem of large deviation in the axial length of the front and rear ends after the production of the large opening angle section 1.

[0050] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A manufacturing method for a large-opening-angle section of austenitic stainless steel, characterized in that, It includes the following steps: S1. Shell forming: Divide the circumferential side wall of the integral shell of the large opening angle section into multiple layers of layered shells along the height direction according to the size of the large opening angle section of the wind tunnel and the processing capacity of the three-dimensional numerical control bending machine, and divide the circumferential side wall of each layer of the layered shell into multiple segmented shells at equal intervals in the circumferential direction, and the number of the segmented shells in each layer is the same; Unfold and lay out each of the segmented shells to obtain an unfolded layout drawing; Cut the material for each of the segmented shells according to the unfolded layout drawing, and reserve a forming allowance on the outer contour of the multiple segmented shells when cutting the material; Use a beveling machine to prepare a bevel for the segmented shell, use the three-dimensional numerical control bending machine to press the segmented shell into shape, and after shaping, use a template to check the surface accuracy of the segmented shell, and use a hydraulic press to perform point pressing and straightening on the local positions where the surface accuracy of the segmented shell does not meet the requirements; S2. Design a corresponding surface tooling according to the size of the large opening angle section: The surface tooling includes multiple surface ribs, multiple layers of circumferential ribs, multiple layers of cross braces, and a hoisting support; The outer end faces of the multiple surface ribs in the width direction are fitted to the inner surface of the integral shell, and are circumferentially spaced around the central axis of the integral shell, and the number of the surface ribs is the same as the number of the segmented shells on each layer of the layered shell; The multiple layers of circumferential ribs are all in an annular structure and are arranged in parallel at intervals around the central axis of the integral shell, and are spaced from the entrance to the exit of the integral shell along the central axis of the integral shell, and the outer end faces of the circumferential ribs in the width direction are fitted to the inner surface of the integral shell; The hoisting support is arranged in a direction perpendicular to the central axis of the integral shell and is located in the middle of the cavity jointly surrounded by the multiple layers of circumferential ribs, and the respective angular ends in the circumferential direction are respectively connected to the circumferential ribs at the middle part; The multiple layers of cross braces are arranged in parallel at intervals in sequence in the cavity along a direction perpendicular to the central axis of the integral shell, the hoisting support is located between the two adjacent cross braces above and below, and the respective angular ends in the circumferential direction of each cross brace are respectively connected to the corresponding circumferential ribs; S3. Vertically assemble the surface tooling: First, assemble the circumferential rib at the exit of the large opening angle section on the steel plate platform, adjust the elevations of the upper surfaces of the circumferential ribs at the exit of the large opening angle section to the same height and assemble the cross braces, then assemble the surface ribs on the circumferential rib at the exit of the large opening angle section, and then sequentially assemble the circumferential ribs, the cross braces, and the hoisting support of other layers layer by layer in a direction away from the exit of the large opening angle section until the assembly is completed, and finally perform reinforcement welding on the surface tooling; S4. Vertically assemble and weld the segmented shell layer by layer from the outlet of the large opening angle section towards the inlet: First, assemble the segmented shell at the outlet of the large opening angle section. Fit the inner surface of the segmented shell to the outer end surface of the profile rib in the width direction and assemble it. After assembly, adjust the misalignment amount to make the central axis of this layer of the segmented shell collinear with the central axis of the profile tooling. Use the same method to successively assemble the segmented shells of other layers layer by layer in the direction away from the outlet of the large opening angle section until the assembly is completed. Finally, tack-weld each segmented shell to the profile tooling. Weld the segmented shell using tungsten inert gas welding. First, perform backing welding on the segmented shell, then fill and cover the weld groove on the inner wall of the segmented shell, then install anti-deformation longitudinal ribs along the longitudinal weld on the inner wall of the segmented shell, and install anti-deformation circumferential ribs along the circumferential weld on the inner wall of the segmented shell. Finally, fill and cover the weld groove on the outer wall of the segmented shell. S5. Cut and install the assembled integral shell: After welding the multi-layer segmented shells, assemble and weld the reinforcing ribs to form the integral shell. Measure the projected length of the integral shell in the central axis direction, and measure the inner circumferences of the integral shell at the inlet and outlet respectively. According to the design dimensions of the large opening angle section combined with the measured data, cut the forming allowances reserved at the inlet and outlet of the integral shell, and finally install and weld the flanges on the integral shell.

2. The method for manufacturing the large-opening-angle section of austenitic stainless steel according to claim 1, characterized in that, In step S1, for the segmented shell of this layer at the inlet position of the large opening angle section, reserve 10 - 20 mm of forming allowance on the inlet ends and both side ends of the outer contours of any two selected segmented shells respectively, and reserve 10 - 20 mm of forming allowance on the inlet ends of the outer contours of the remaining segmented shells respectively; for the segmented shell of this layer at the outlet position of the large opening angle section, reserve 10 - 20 mm of forming allowance on the outlet ends and both side ends of the outer contours of any two selected segmented shells respectively, and reserve 10 - 20 mm of forming allowance on the outlet ends of the outer contours of the remaining segmented shells respectively; for the segmented shell at other positions of the large opening angle section, reserve 10 - 20 mm of forming allowance on both side ends of the outer contours of any two selected segmented shells respectively, and do not reserve forming allowance on the outer contours of the remaining segmented shells.

3. The method for manufacturing the large-opening-angle section of austenitic stainless steel according to claim 1, characterized in that In step S1, after cutting multiple segmented shells, use the beveling machine to prepare bevels at the ports of the segmented shells without reserved forming allowance, and the bevels are X-shaped symmetric bevels.

4. The manufacturing method of the austenitic stainless steel large opening angle section according to claim 1, characterized in that, In step S2, the projection lengths of the shaped gluten and the integral housing in the central axis direction are the same; the size of the circular ring formed by enclosing multiple layers of the circumferential ribs gradually increases from the inlet to the outlet direction of the integral housing, and the distance between adjacent circumferential ribs is 500 - 800 mm. The circumferential rib at the outlet of the large opening angle section is an integral circular ring plate, and multiple shaped gluten are installed at intervals on the upper surface. Each layer of the circumferential rib at other positions of the large opening angle section is a segmented circular ring plate and is penetrated by the corresponding shaped gluten of each layer.

5. The method for manufacturing the large-opening-angle section of austenitic stainless steel according to claim 1, characterized in that, In step S2, the hoisting support is made of multiple H-shaped steels and is installed at the middle position of the shaped surface tooling in the central axis direction of the integral housing.

6. The manufacturing method of the large-opening-angle section of austenitic stainless steel according to claim 2, characterized in that, In step S4, when assembling the segmented housing at the outlet of the large opening angle section, first assemble the segmented housing with forming allowance reserved at the outlet end of the outer contour, then assemble the segmented housing with forming allowance reserved at the outlet end and both side ends of the outer contour, and the last two segmented housings assembled are symmetric about the central axis of the integral housing; when assembling the segmented housing at the inlet of the large opening angle section, first assemble the segmented housing with forming allowance reserved at the inlet end of the outer contour, then assemble the two segmented housings with forming allowance reserved at the inlet end and both side ends of the outer contour, and the last two segmented housings assembled are symmetric about the central axis of the integral housing; when assembling each layer of the segmented housing at other positions of the large opening angle section, first assemble the segmented housing without forming allowance on the outer contour, then assemble the two segmented housings with forming allowance reserved at both side ends of the outer contour, and the last two segmented housings assembled are symmetric about the central axis of the integral housing.

7. The method for manufacturing the large-opening-angle section of austenitic stainless steel according to claim 6, characterized in that, In step S4, before assembling the segmented housing with forming allowance at the outlet end and both side ends of the outer contour, first use a grinding wheel to cut and repair both side ends of the segmented housing; before assembling the segmented housing with forming allowance at the inlet end and both side ends of the outer contour, first use a grinding wheel to cut and repair both side ends of the segmented housing; before assembling the segmented housing with forming allowance at both side ends of the outer contour, first use a grinding wheel to cut and repair both side ends of the segmented housing.

8. The method for manufacturing a large-opening-angle section of austenitic stainless steel according to claim 1, characterized in that, In step S4, each longitudinal weld on the inner wall of the segmented housing is correspondingly installed with an anti-deformation longitudinal bar. The outer end surface of the anti-deformation longitudinal bar in the width direction is fitted with the inner surface of the segmented housing at the longitudinal weld, and the top and bottom ends of the anti-deformation longitudinal bar are respectively vertically welded between the two adjacent circumferential ribs; each circumferential weld on the inner wall of the segmented housing is correspondingly installed with an anti-deformation circumferential bar. The outer end surface of the anti-deformation circumferential bar in the width direction is fitted with the inner surface of the segmented housing at the circumferential weld, and the two ends of the anti-deformation circumferential bar are respectively vertically welded between the two adjacent shaped gluten.

9. The method for manufacturing a large-opening-angle section of austenitic stainless steel according to claim 1, characterized in that, In step S5, the inlet of the integral housing is cut by a plasma cutting machine, and the outlet of the integral housing is cut by a grinding wheel.

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