Method for manufacturing a steel containment shell in sections

Abstract

This invention provides a method for segmented fabrication of a steel containment vessel, comprising: marking and cutting a composite plate into a straight composite plate, a single-curved composite plate, and a spherical composite plate; processing the single-curved and spherical composite plates into shapes; beveling the straight, single-curved, and spherical composite plates; assembling component groups using horizontal girder and bulkhead; assembling component groups using the transverse bulkhead as a reference to form a large transverse bulkhead assembly and checking the flatness of the bulkhead top; flipping the large transverse bulkhead assembly and assembling component groups and the side longitudinal walls as references, checking the flatness of the bulkhead top; sequentially installing the spherical composite plate, the single-curved composite plate, and the straight composite plate onto the top of the bulkhead; performing segmented sandblasting on the base layers of the straight, single-curved, and spherical composite plates; and after sandblasting, applying primer, acid pickling and passivation, and applying a protective film.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding, and in particular to a method for manufacturing steel containment sections. Background Technology

[0002] The reactor compartment structure of Chinese civilian ships primarily provides space, dimensional constraints, and containment for the equipment and systems within the compartment. In terms of structural design, the containment structure adopts a double-layered square grid-type structure, consisting of inner wall panels, horizontal and vertical support structures, and outer wall panels. It is installed above the hull bottom plate. Rounded transitions are used at the connections between the inner wall panels and between the inner wall panels and the top and bottom structures. Regarding materials, based on the design pressure, temperature load, and corrosion resistance requirements of the design reference conditions, the inner wall panels of the reactor compartment are made of high-strength low-alloy steel (base material) and 304L stainless steel (cladding material) bonded together through explosive bonding. The remaining inner and outer shell spacers and outer shell panels are all made of a single grade of high-strength low-alloy steel.

[0003] Based on the aforementioned structural design and material application characteristics, the difficulty in constructing the containment structure of the hull lies in the segmentation of the corner area where the bottom of the hull structure connects to the side and the forward bulkhead (e.g., Figure 2 The main dimensions of the structure are 3.5 meters (length) × 3.5 meters (width) × 3.5 meters (height). This section includes the assembly and welding of three types of composite plates: flat composite plates, single-curved composite plates, and spherical composite plates. Due to the high precision requirements for the butt joint of the composite steel plates, problems such as misalignment and excessive gaps are easily caused by poor precision during assembly and positioning. This leads to rework such as local cutting and correction of the section. At the same time, since the construction of the section involves more than ten construction processes such as composite steel plate transportation, hoisting, parts cutting, curvature processing, beveling, storage, assembly, and welding, the stainless steel surface of the composite steel plates is prone to surface defects such as oil stains, scratches, and pitting due to improper operation during the long-term and multi-site construction process, which will also affect the construction quality. Summary of the Invention

[0004] In view of the shortcomings of the above-mentioned related technologies, the purpose of this invention is to provide a method for manufacturing steel containment structures in sections.

[0005] To achieve the above and other related objectives, the present invention provides a method for manufacturing steel containment structures in sections, the method comprising:

[0006] The composite board is scribing and cut into flat composite board, single-curved composite board and spherical composite board. The single-curved composite board and spherical composite board are processed and shaped. The flat composite board, single-curved composite board and spherical composite board are beveled.

[0007] The components are assembled into groups using horizontal trusses and partitions.

[0008] Using the transverse bulkhead as a reference, assemble the component groups on the transverse bulkhead to form the large transverse bulkhead assembly, and check the flatness of the top of the bulkhead, where the top of the bulkhead is the mounting surface of the bulkhead mounting composite plate.

[0009] The transverse bulkhead is rotated and assembled, and the components are assembled with the side longitudinal bulkhead as a reference. The flatness of the top of the bulkhead is checked.

[0010] The spherical composite panel, the single-curved composite panel, and the flat composite panel are sequentially installed on the upper part of the partition to form a segmented mounting shell.

[0011] The base layer of flat composite panels, single-curved composite panels and spherical composite panels is subjected to segmented sandblasting, and the primer is applied after sandblasting is completed.

[0012] After the painting is completed, the segmented inner shell is pickled and passivated, and a protective film is applied.

[0013] Optionally, when scribing the composite plate, UV curing scribing is performed on the composite plate. For flat composite plates, the outline of the part is scribed; for spherical composite plates, the outline of the part and the precision inspection line are scribed; and for single-curved composite steel plates, the outline of the part and the processing position line are scribed.

[0014] Optionally, before marking the lines, check the flatness of the composite board. The flatness accuracy should not exceed 8mm / m.

[0015] Optionally, when processing the spherical composite board, a hydraulic press and matching processing mold are used for multi-point cold pressing. When processing the spherical single-curved composite board, a three-core roller is used, and a layer of plywood is placed on its composite surface.

[0016] Optionally, when beveling the flat composite plate, the single-curved composite plate, and the spherical composite plate, a stepped bevel is used, and the surface roughness of the bevel after processing should be ≤Ra12.5μm, and the positive tolerance of the part's external dimensions should be 0~2.0mm.

[0017] Optionally, after the beveling process, the base layer of the composite board is subjected to PT penetrant testing, and the cladding layer is subjected to MT magnetic particle testing.

[0018] Optionally, the steps of assembling the horizontal truss and partitions into a component group are as follows: first, the horizontal truss is assembled and the horizontal truss is corrected; the primer on the horizontal truss corresponding to the area where the partition is installed is polished; the partition installation position line is drawn; a baseline is set and the continuous horizontal truss at a preset height from the baseline is used as a reference; the corresponding partitions are installed respectively; and two adjacent horizontal trusses are connected by a partition structure.

[0019] Optionally, before assembling the side longitudinal walls, angle steel can be added between the component assembly and the side longitudinal walls for temporary reinforcement.

[0020] Optionally, after the spherical composite panel, single-curved composite panel and flat composite panel are assembled, reinforcing plates are set at equal intervals of 300mm on one side of the substrate of each composite panel at the butt weld, and pressure irons are used to control deformation.

[0021] Optionally, the cladding surfaces and edges of each composite panel can be masked before sandblasting.

[0022] As described above, the steel containment structure segment manufacturing method of the present invention has the following beneficial effects: by adopting the method of the present invention, more than ten construction processes such as scribing and cutting, bending, beveling, storage, assembly and welding of composite plates can be strictly controlled, thereby achieving precision control and improving the quality of structural construction. Attached Figure Description

[0023] Figure 1 The diagram shown is a schematic representation of a large assembly in an embodiment of the present invention.

[0024] Figure 2 The diagram shown is a schematic representation of a horizontal truss in an embodiment of the present invention.

[0025] Figure 3 The diagram shown is a schematic representation of the containment structure segments in an embodiment of the present invention.

[0026] Component designation explanation

[0027] 1. Flat composite panel; 2. Single-curved composite panel; 3. Spherical composite panel; 4. Horizontal girder; 5. Bulkhead; 51. Bulkhead opening; 6. Transverse bulkhead; 7. Side longitudinal bulkhead. Detailed Implementation

[0028] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0029] In the detailed description of embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged and not to scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0030] For ease of description, spatial relation terms such as “below,” “under,” “lower than,” “below,” “above,” and “upper” may be used herein to describe the relationship between one element or feature shown in the accompanying drawings and other elements or features. It will be understood that these spatial relation terms are intended to include directions other than those depicted in the drawings for the device in use or operation. Furthermore, when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or there may be one or more layers in between. The phrase “between” as used herein includes both endpoint values.

[0031] In the context of this application, the structure described above the first feature may include embodiments in which the first and second features are formed in direct contact, or embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0032] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0033] like Figure 1 As shown in the figure, this embodiment provides a method for manufacturing steel containment structures in sections. The steps of this method include:

[0034] S1. Mark and cut the composite board into straight composite board 1, single-curved composite board 2 and spherical composite board 3, and process the single-curved composite board 2 and spherical composite board 3 into shape.

[0035] The composite panel consists of a base layer and a stainless steel overlay. Before marking, check the flatness of the composite panel. If the flatness accuracy is greater than 8mm / m, the composite panel should be leveled.

[0036] When scribing composite plates, UV curing should be performed on the stainless steel surface of the composite plate. For flat composite plate 1, at least the outline of the part should be scribed. For spherical composite plate 3, the outline of the part and the precision inspection line (30° angle bisector line) should be scribed. For single-curved composite steel plate, the outline of the part and the processing position line should be scribed.

[0037] Then, according to the outline of the part, a CNC plasma cutting machine is used to cut the material. After the material is cut, a three-core roller and a hydraulic press are used for processing and forming. For example, spherical composite steel is processed by multi-point cold pressing using a hydraulic press and matching processing mold (the roller surface of the pressure head needs to be protected with a glaze layer). When single-curved composite board 2 is processed by a three-core roller, a layer of plywood needs to be placed on the stainless steel surface. After processing, a protective film is applied.

[0038] For the beveling of flat composite plate 1, single-curved composite plate 2 and spherical composite plate 3, considering the heat-affected zone of plasma cutting and the requirement for straight edges at the curved processing ends, a 50mm allowance is added to each side of the butt weld of flat composite plate 1, single-curved composite plate 2 and spherical composite plate 3. A stepped beveling is adopted. After processing, the surface roughness of the beveling should be ≤Ra12.5μm, and the positive tolerance of the part's external dimensions (length, width) should be 0~2.0mm. The beveling angle, root allowance and other dimensions after machining meet the requirements of GJB3182A-2018.

[0039] When processing the bevel, in order to completely remove the cladding layer at the bevel, the thickness needs to be further removed by 0.2mm to 0.5mm from the base layer.

[0040] The bevels of the single-curved composite plate 2 and the spherical composite plate 3 are achieved by using a combination of "1:1 modeling + physical scanning of spatial curved edges" to match the optimal machining trajectory, thus realizing the automatic machining of complex curved surface bevels by a CNC moving beam gantry milling machine.

[0041] During machining, absorbent cotton should be laid, and oil stains in the oil tank should be cleaned. After machining, the bevel should be inspected. The base layer should be tested with PT penetration testing, and the superlayer should be tested with MT magnetic particle testing. Finally, a protective film should be applied, and the layers should be stacked as required.

[0042] The assembly components are assembled using horizontal truss 4 and partition 5.

[0043] First, install the horizontal truss 4 panels and then correct the horizontal truss 4. The structure of the horizontal truss 4 is as follows: Figure 2 As shown, after the horizontal truss 4 is straightened, the primer on the area where the partition plate 5 is installed on the horizontal truss 4 is polished, and the installation position line of the partition plate 5 is marked. A baseline is set and the continuous horizontal trusses 4 at a height of 1 meter, 2 meters and 3 meters from the baseline are used as a reference. The corresponding partition plates 5 are installed respectively. The two adjacent horizontal trusses 4 are connected by the partition plate 5 structure. When the partition plate 5 is positioned, it is aligned with the horizontal truss 4.

[0044] In subsequent assembly, for situations requiring the splicing of multiple flat composite plates 1, these plates can be pre-assembled to form a composite plate group. When assembling multiple flat composite plates 1, the misalignment of the butt joints must be controlled to be ≤2.0mm, the bevel gap ≤2.0mm, and the flatness of the butt joints ≤2.0mm. Before welding the spliced ​​plates, appropriate measures such as using weights and reinforcing plates should be taken to control deformation and prevent cracks in the weld during flipping. When welding the spliced ​​plates, the protective film around the weld should be removed, and a fireproof blanket or heat insulation cotton should be laid within a certain range around the weld (with aluminum foil attached to the edges for sealing). The group assembly welding should be completed according to the welding process requirements, and welding deformation should be corrected and touch-up paint should be applied.

[0045] The components are assembled from the sub-assemblies into a larger assembly, and then the single-curved composite plate 2, the spherical composite plate 3, and the straight composite plate 1 are installed on the larger assembly to form the containment segment. Among them, the single-curved composite plate 2, the spherical composite plate 3, and the straight composite plate 1 form the inner shell, the transverse bulkhead 6 and the side longitudinal bulkhead 7 form the outer plate, and the horizontal girder 4 and the bulkhead 5 form the internal structure.

[0046] Mark the rib lines, segment center lines, etc. on a special jig or iron platform. Since marking is a mature technology, it will not be described in detail here. When marking, add a precision compensation amount in the length and width directions. After the marking is completed, the deviation of the internal component position marking should be checked to be ≤2.0mm.

[0047] First, using the forward transverse bulkhead 6 as a reference, install the component groups one by one to form the large assembly of transverse bulkhead 6, and check the flatness of the top edge 51 of the bulkhead. The top edge 51 of the bulkhead is the mounting surface for the composite plate of the bulkhead 5. When assembling and positioning the component groups, strictly follow the process requirements of the mating line and assembly line to ensure the process accuracy and quality requirements of the connection between each assembly. The assembly of the component groups should be carried out in strict accordance with the process and should meet the assembly process technical requirements.

[0048] The transverse bulkhead 6 is assembled and turned over to a state with the side longitudinal bulkhead 7 as the reference. Before welding, temporary reinforcing structures such as angle steel are added between the component assembly and the side longitudinal bulkhead 7. First, the fillet welds and corrections of the internal structure (horizontal truss 4, bulkhead 5) and the side longitudinal bulkhead 7 are completed. Then, the overall flatness of the upper part 51 of the bulkhead on the composite plate mounting surface (after beveling) is measured to be ≤2.0mm, and corrections are made if necessary.

[0049] Install the composite steel plates sequentially, as follows:

[0050] Based on the theoretical dimensions of the corner composite plate port (rib direction, longitudinal and horizontal height direction) and the theoretical dimensions of the stainless steel layer of the composite steel plate, first position the spherical composite plate 3, then position and install the single-curved composite plate 2, ensuring that the dimensions of the curved surface line type, bevel gap, misalignment, etc. meet the requirements. Finally, install the straight composite plate 1, controlling the misalignment of the butt joint assembly to be ≤2.0mm (the linear matching degree between the spherical composite plate 3 and the single-curved composite plate 2), the butt bevel gap to be ≤2.0mm, and the flatness of the butt joint to be ≤2.0mm.

[0051] After assembly, reinforcing plates are installed at approximately 300mm intervals on one side of each composite plate substrate at the butt weld joint. Weights and other tooling measures are used to control deformation. Each composite plate must be protected with stainless steel before welding. When parts need to be in a vertical position during assembly or turning, only steel lifting devices are permitted on the substrate surface for lifting (removal of the lifting devices requires grinding and flaw detection). Before welding the composite plates, the protective film around the weld should be removed. Magnets should be used to install and fix fireproof blankets or heat insulation cotton within a certain range around the weld, and aluminum foil should be applied to the edges for sealing.

[0052] Deformation correction is performed mechanically (fireworks are not allowed on composite panels). If necessary, internal components are repaired by welding to ensure that the flatness of the composite panel is ≤4.0mm / rib spacing.

[0053] Foreign stamping marks are made at the locations of inspection lines such as the segment center line and rib line.

[0054] The base layers of flat composite board 1, single-curved composite board 2 and spherical composite board 3 are sandblasted in sections. After sandblasting, primer is applied. At the same time, the composite layers of flat composite board 1, single-curved composite board 2 and spherical composite board 3 are checked for scratches or other surface defects. Worn parts are cleaned and covered with a protective film.

[0055] Surface protection before sandblasting: Use a 2.0mm thick black rubber to mask the surface of the composite layer. The black rubber should be tightly attached to the surface of the composite layer. On the outside of the black rubber, use a sheet metal for secondary masking to further enhance the protective effect.

[0056] Free edge protection before sandblasting: Use clamps or tools to firmly fix the black rubber and galvanized iron sheet at the edge to ensure that the protective material will not shift or fall off during rust removal and painting operations.

[0057] Pre-sandblasting gap treatment: Use aluminum foil tape to tightly seal the edges and the gaps where the black rubber overlaps with the galvanized iron sheet, ensuring that the multilayer surface is fully and effectively protected.

[0058] Segmented sandblasting and coating should be carried out according to process requirements; direct sandblasting of the stainless steel surface is prohibited. After coating, the segmented inner shell should be pickled and passivated, and a protective film should be applied.

[0059] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for manufacturing a steel containment vessel in sections, characterized in that, The method includes: The composite board is scribing and cut into flat composite board, single-curved composite board and spherical composite board. The single-curved composite board and spherical composite board are processed and shaped. The flat composite board, single-curved composite board and spherical composite board are beveled. The components are assembled into groups using horizontal trusses and partitions. Using the transverse bulkhead as a reference, assemble the component groups on the transverse bulkhead to form the large transverse bulkhead assembly, and check the flatness of the top of the bulkhead, where the top of the bulkhead is the mounting surface of the bulkhead mounting composite plate. The transverse bulkhead is rotated and assembled, and the components are assembled with the side longitudinal bulkhead as a reference. The flatness of the top of the bulkhead is checked. The spherical composite panel, the single-curved composite panel, and the flat composite panel are sequentially installed on the upper part of the partition to form a segmented mounting shell. The base layer of flat composite panels, single-curved composite panels and spherical composite panels is subjected to segmented sandblasting, and the primer is applied after sandblasting is completed. After the painting is completed, the segmented inner shell is pickled and passivated, and a protective film is applied.

2. The method for manufacturing segmented steel containment structures according to claim 1, characterized in that: When scribing the composite plate, UV curing scribing is performed on the composite plate. For flat composite plates, the outline of the part is scribed; for spherical composite plates, the outline of the part and the precision inspection line are scribed; and for single-curved composite steel plates, the outline of the part and the processing position line are scribed.

3. The method for manufacturing segmented steel containment structures according to claim 1, characterized in that: Before marking lines, check the flatness of the composite board. The flatness accuracy should not exceed 8mm / m.

4. The method for manufacturing segmented steel containment structures according to claim 1, characterized in that: When the spherical composite board is processed and formed, a hydraulic press and matching processing mold are used for multi-point cold pressing. When the spherical single-curved composite board is processed and formed, a three-core roller is used, and a layer of plywood is placed on its composite surface.

5. The method for manufacturing segmented steel containment structures according to claim 1, characterized in that: When beveling the flat composite plate, the single-curved composite plate, and the spherical composite plate, a stepped bevel is used. After processing, the surface roughness of the bevel should be ≤Ra12.5μm, and the positive tolerance of the part's external dimensions should be 0~2.0mm.

6. The method for manufacturing segmented steel containment structures according to claim 1, characterized in that: After the beveling process, the base layer of the composite board is inspected using PT penetrant testing, and the cladding layer is inspected using MT magnetic particle testing.

7. The method for manufacturing segmented steel containment structures according to claim 1, characterized in that: The steps for assembling the component group using horizontal trusses and partitions are as follows: First, the horizontal trusses are assembled and corrected. The primer on the horizontal trusses corresponding to the area where the partitions are installed is polished, and the partition installation position line is drawn. A baseline is set, and the corresponding partitions are installed respectively based on the continuous horizontal trusses at a preset height from the baseline. Adjacent horizontal trusses are connected by a partition structure.

8. The method for manufacturing segmented steel containment structures according to claim 1, characterized in that: Before assembling the side longitudinal wall, add angle steel between the component group and the side longitudinal wall for temporary reinforcement.

9. The method for manufacturing segmented steel containment structures according to claim 1, characterized in that: After the spherical composite panel, single-curved composite panel and flat composite panel are assembled, reinforcing plates are set at equal intervals of 300mm on one side of the substrate of each composite panel at the butt weld, and pressure irons are used to control deformation.

10. The method for manufacturing segmented steel containment structures according to claim 1, characterized in that: Before sandblasting, the surface of each composite panel and its edges are masked.

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