A method for welding and forming a spherical shell structure of a closed confined space

Abstract

The present application relates to the technical field of structural welding manufacturing, and particularly relates to a welding forming method for a closed and limited space spherical shell structure, which comprises the following steps: S1, component preparation, preparing a forged component comprising an upper spherical shell and a lower spherical shell, the upper spherical shell is provided with a first matching part at the position of a weld root corresponding to a to-be-welded groove, and the lower spherical shell is provided with a second matching part; S2, component assembly, combining the upper spherical shell and the lower spherical shell to form a spherical shell structure, and forming a weld space which is closed at the weld root; S3, weld application, adopting submerged arc automatic welding to weld the weld space; and S4, root trimming, removing the first matching part and the second matching part along the inner wall of the spherical shell structure by using a mechanical processing mode. The simple and quick positioning and assembly of the upper spherical shell and the lower spherical shell can be realized, and the assembly efficiency is improved. Meanwhile, other structures for closing the weld space are not needed to be additionally arranged, the structural integrity of the weld space forming the spherical shell structure is ensured, the weld root welding quality at the position of the inner wall of the spherical shell structure is ensured to meet the detection requirements, and the welding efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of structural welding manufacturing technology, and specifically to a welding and forming method for a confined space spherical shell structure. Background Technology

[0002] like Figure 1 The image shows a thick-walled spherical shell equipment. The design and operating pressure of this spherical shell structure equipment are both above 100MPa. The inner diameter of the shell is only 738mm, and the inner diameter of the opening on the shell is relatively small, with the largest opening being φ350mm. The shell design is composed of two thick-walled spherical shell forgings welded together. High weld quality is required, and after welding, the welds need to undergo 100% MT, 100% UT, and 100% RT non-destructive testing to ensure welding quality and operational safety. 100% MT is performed according to the requirements of standard NB / T47013.4-2015, with a testing quality level of Class I; 100% UT is performed according to the requirements of standard NB / T47013.3-2023, with a testing technology level no lower than Class C and a quality level of Class I; 100% RT is performed according to the requirements of standard NB / T47013.2-2015, with a testing technology level no lower than Class B and a quality level of Class II.

[0003] Due to the large weld thickness (215mm), submerged arc welding (SAW) is typically used to improve weld quality and efficiency. After the SAW is fully welded at the bevel, carbon arc gouging is required to clean the root of the weld. After the cleaned area is polished to a metallic luster and passes 100% MT inspection, shielded metal arc welding (SMAW) is used for root sealing to ensure the quality of the root weld. However, because the opening size on the spherical shell structure is small, it is not possible for the operator to enter the spherical shell through the opening to clean, grind, and weld the root of the weld. Welding can only be performed from the outside. Welding from the outside of the thick-walled spherical shell does not easily ensure that the welding quality at the root of the weld meets the inspection requirements, affecting the processing efficiency and forming quality of the confined space spherical shell structure. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies in the preparation of spherical shell structure equipment, which cannot guarantee that the welding quality at the root of the weld meets the inspection requirements, thus affecting processing efficiency and forming quality. This invention provides a welding and forming method for spherical shell structures in a closed and confined space.

[0005] This invention provides a welding and forming method for a confined space spherical shell structure, comprising:

[0006] S1, component preparation, a forged component including an upper spherical shell and a lower spherical shell is prepared, the upper spherical shell is provided with a first fitting part protruding at a position corresponding to a weld root of a to-be-welded groove, the lower spherical shell is provided with a second fitting part protruding at a position corresponding to the weld root, and the first fitting part and the second fitting part can be nestedly fitted;

[0007] S2, component assembly, the upper spherical shell and the lower spherical shell are combined to form a spherical shell structure, the first fitting part and the second fitting part are abutted, and a weld space closed at the weld root is formed;

[0008] S3, weld welding, the weld space is welded by using submerged arc automatic welding;

[0009] S4, root trimming, the first fitting part and the second fitting part are removed along the inner wall of the spherical shell structure by using a machining method.

[0010] Preferably, the upper spherical shell is a cylindrical structure, the lower spherical shell is provided with an assembly hole, and the upper spherical shell and the lower spherical shell are assembled to form the spherical shell structure.

[0011] Preferably, in S1, the upper spherical shell and the lower spherical shell are provided with a reserved material allowance towards the inside of the spherical shell structure at a position corresponding to the weld root, to form the first fitting part and the second fitting part.

[0012] Preferably, the first fitting part includes a sunken platform, the second fitting part includes a protruding part, and the protruding part and the sunken platform are nestedly fitted.

[0013] Preferably, the protruding part is provided with an arc surface at a position corresponding to the bottom surface of the weld space.

[0014] Preferably, in S2, after the first fitting part and the second fitting part are combined, the thickness H in the depth direction of the weld space satisfies: 6mm≤H≤8mm.

[0015] Preferably, after the first fitting part and the second fitting part are combined, the bottom of the weld space extends beyond the inner wall of the spherical shell structure, and the thickness L by which the weld space extends beyond the inner wall of the spherical shell structure is greater than or equal to the thickness of two layers of weld metal.

[0016] Preferably, the lower spherical shell is supported on a support, an isolation structure is arranged between the lower spherical shell and the support, a preheating tool is arranged on the top of the support, and the preheating tool is located above the weld space.

[0017] Preferably, in S3, the preheating tool is used to preheat the groove and both sides, and after welding is completed, stress relief heat treatment is directly performed, or after welding is completed, the temperature is heated to 300-350℃, and after holding for at least 2h, the preheating temperature is maintained until stress relief heat treatment is performed.

[0018] Preferably, in S3, continuous welding is performed by using submerged arc automatic welding, or when welding work is interrupted, the temperature at the weld is maintained to be not lower than the preheating temperature by using the preheating tool until welding work is restarted.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] 1. The present application provides a welding forming method for a closed and limited space spherical shell structure, which can realize simple and fast positioning and assembly of the upper spherical shell and the lower spherical shell through the nested abutting cooperation of the first fitting part and the second fitting part, and improve the assembly efficiency.

[0021] 2. The present application provides a welding forming method for a closed and limited space spherical shell structure, which can realize the closure of the weld space at the root of the weld during the assembly of the upper spherical shell and the lower spherical shell through the nested cooperation of the first fitting part and the second fitting part, and define the area for the filler metal, so that the upper spherical shell and the lower spherical shell do not need to be additionally provided with other structures to close the weld space after being combined, and the operator does not need to enter the spherical shell structure.

[0022] 3. The present application provides a welding forming method for a closed and limited space spherical shell structure, which can ensure the structural integrity of the weld space of the spherical shell structure by protruding the first fitting part and the second fitting part towards the inside of the spherical shell, and can ensure that the quality of the weld root at the position of the inner wall of the spherical shell structure meets the detection requirements after the first fitting part and the second fitting part are removed.

[0023] 4. The present application provides a welding forming method for a closed and limited space spherical shell structure, which forms a root-closed weld space by protruding the first fitting part and the second fitting part towards the inside of the spherical shell structure, and fills the weld space by submerged arc automatic welding, so that only the removal of the first fitting part and the second fitting part is needed after welding, without the need for additional root cleaning and welding action on the weld root, which can effectively ensure the quality of the weld root and improve the welding efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a cross-sectional structure diagram of a certain spherical shell structure device in the background art.

[0025] Figure 2 It is a flowchart of a welding forming method for a closed and limited space spherical shell structure in Example 1.

[0026] Figure 3 It is a schematic diagram of the welding state of the spherical shell structure in Example 1.

[0027] Figure 4 It is a structural diagram of the position of the weld space after the combination of the upper spherical shell and the lower spherical shell in Example 1.

[0028] Figure 5 It is a structural diagram of the weld space before welding in Example 1.

[0029] Figure 6Structure schematic diagram of the structure after welding of the weld space in Example 1.

[0030] Figure 7 Structure schematic diagram of the inner wall of the spherical shell structure after root dressing in Example 1.

[0031] Markings in the figure:

[0032] 1 - spherical shell structure, 11 - upper spherical shell, 12 - lower spherical shell, 2 - first fitting part, 3 - second fitting part, 31 - arc surface, 4 - weld space, 5 - support, 6 - isolation structure, 7 - preheating tool. DETAILED DESCRIPTION

[0033] The application will be further described in conjunction with specific embodiments. However, it should not be understood as the scope of the above-mentioned subject matter of the application being limited to the following embodiments, and any technology realized based on the content of the application falls within the scope of the application.

[0034] In the description of the specific embodiments of the application, the orientation or position relationship terms such as "upper", "lower", "left", "right", "center", "inner", "outer" and the like appearing without special indication are expressed based on the orientation or position relationship shown in the drawings, or the orientation or position relationship when the product / equipment / device of the application is usually used. These orientation or position relationship terms are only for the convenience of describing the application scheme or simplifying the description in the specific embodiments, for the convenience of the technicians to quickly understand the scheme, and are not intended to indicate or imply that a specific device / part / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the application.

[0035] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel", "coaxial" and the like appear in the terms, it does not mean that the corresponding device / component / element is absolutely horizontal or vertical or overhanging or parallel or coaxial, but can be slightly inclined or deviated, as long as it does not affect the normal function of the related component. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", not that the structure must be completely horizontal, but can be slightly inclined; "coaxial" means that two components are coaxially arranged as much as possible, and move in a coaxial or approximately coaxial manner when the relative position changes. Alternatively, it can be simplified to understand that the corresponding device / component / element is arranged in the "horizontal", "vertical", "overhanging", "parallel", "coaxial" direction, which can have an error / bias of ±10% relative to the corresponding direction, more preferably an error / bias of ±8%, more preferably an error / bias of ±6%, more preferably an error / bias of ±5%, more preferably an error / bias of ±4%. For example, the deviation in the "coaxial" direction is controlled within 0.2-1mm, preferably within 0.2-0.5mm. As long as the corresponding device / component / element is within the error / bias range, it can still achieve its role in the present application.

[0036] In addition, the terms "first", "second", "third" and the like in the terms are only used to distinguish the same or similar components for description, and should not be understood as emphasizing or implying the relative importance of the specific components.

[0037] In addition, in the description of the embodiments of the present application, "several", "a plurality of", "several" represent at least 2. It can be 2, 3, 4, 5, 6, 7, 8, 9, etc. Any case, it can even be more than 9 cases.

[0038] In addition, in the description of the technical solutions of the present application, unless otherwise specified / limited / limited, the terms "arrangement", "installation", "connection", "connection", "provided with", "laid", "arrangement" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, which can be welding, riveting, bolting, screwing and other commonly used connection means in the art. The connection can be mechanical connection, electrical connection or communication connection; it can be directly connected or indirectly connected through an intermediate medium; it can be the communication between two elements.

[0039] Embodiment 1

[0040] As shown in Figures 2-7 A welding forming method of a closed limited space spherical shell structure, comprising:

[0041] S1, component preparation, prepare the forged components including the upper spherical shell 11 and the lower spherical shell 12, the upper spherical shell 11 is provided with the first fitting part 2 protruding at the position corresponding to the weld root of the to-be-welded groove, the lower spherical shell 12 is provided with the second fitting part 3 protruding at the position corresponding to the weld root of the to-be-welded groove, and the first fitting part 2 and the second fitting part 3 can be nested and fitted;

[0042] S2, component assembly, combine the upper spherical shell 11 and the lower spherical shell 12 to form the spherical shell structure 1, so that the first fitting part 2 and the second fitting part 3 abut to form the weld space 4 closed at the weld root;

[0043] S3, weld welding, the weld space 4 is welded by using submerged arc automatic welding;

[0044] S4, root finishing, the first fitting part 2 and the second fitting part 3 are removed along the inner wall of the spherical shell structure 1 by machining.

[0045] S1 is a material preparation stage before welding, by preparing the forged components of the upper spherical shell 11 and the lower spherical shell 12 respectively, the preparation cost of the spherical shell structure 1 is reduced, and at the same time, the first fitting part 2 and the second fitting part 3 protruding towards the inside of the spherical shell structure 1 are formed during the preparation of the upper spherical shell 11 and the lower spherical shell 12, which makes good structural preparation for welding operation.

[0046] In an optional embodiment, as shown in Figure 3 The upper spherical shell 11 is a part with relatively small volume and weight in the spherical shell structure 1, and is located at the upper side during welding, so as to ensure the structural stability of the spherical shell structure 1 before welding, and to form a stable weld space 4, so as to avoid the influence of the gravity of the upper spherical shell 11 on the weld space 4 and ensure the welding quality.

[0047] In an optional embodiment, the upper spherical shell 11 can be a cylindrical structure, and the lower spherical shell 12 is provided with an assembly hole, and the upper spherical shell 11 and the lower spherical shell 12 are assembled to form the spherical shell structure 1. The upper spherical shell 11 can be a part corresponding to the pipe opening position of the spherical shell structure 1, which facilitates the separate forging preparation of the upper spherical shell 11 and the lower spherical shell 12, and can form a vertically arranged weld space 4 after the upper spherical shell 11 and the lower spherical shell 12 are combined, so that the welding material can fully fill the bottom of the weld space 4 during the welding process, and the welding quality of the weld root is ensured.

[0048] In an optional embodiment, in S1, the upper spherical shell 11 and the lower spherical shell 12 are provided with a material allowance towards the inside of the spherical shell structure 1 at the position corresponding to the weld root to form the first fitting part 2 and the second fitting part 3. The first fitting part 2 and the second fitting part 3 can be the material allowance left during the forging of the forging blank, so that the first fitting part 2 and the second fitting part 3 can be formed without additional increase of the size of the forging blank, thereby avoiding the increase of the size of the forging blank and affecting the preparation cost.

[0049] In an optional embodiment, the first fitting part 2 comprises a sunken surface, and the second fitting part 3 comprises a protruding part, and the protruding part and the sunken surface are nestedly fitted. The sunken surface and the protruding part can be fitted to quickly assemble the upper spherical shell 11 and the lower spherical shell 12, improve the assembly efficiency, and quickly close the bottom of the welding seam space 4 to limit the area filled with the welding filler in the welding seam space 4 without the need of an additional connecting plate or the like to limit and connect the two, and without the need of an operator to enter the spherical shell structure 1 to operate.

[0050] In an optional embodiment, the protruding part is provided with an arc surface 31 at a position corresponding to the bottom surface of the welding seam space 4. The welding filler filled into the welding seam space 4 can sufficiently fill the position of the bottom of the welding seam space 4, and the welding quality of the welding root can be correspondingly improved.

[0051] S2 is a process of combining structures before welding, and the components to be welded are stably supported to provide a stable structural basis for the welding work.

[0052] In an optional embodiment, as shown in Figures 5-6 In S2, the thickness H of the welding seam space 4 in the depth direction satisfies 6mm≤H≤8mm after the first fitting part 2 and the second fitting part 3 are combined. The welding quality of the welding root can be ensured and the lack of welding can be avoided when the submerged arc automatic welding is performed.

[0053] In an optional embodiment, as shown in Figures 5-6 After the first fitting part 2 and the second fitting part 3 are combined, the bottom of the welding seam space 4 extends beyond the inner wall of the spherical shell structure 1, and the thickness L of the welding seam space 4 extending beyond the inner wall of the spherical shell structure 1 is greater than or equal to the thickness of the two layers of welding. The part of the welding seam space 4 extending beyond the inner wall of the spherical shell structure 1 is in the initial stage of the submerged arc automatic welding and is located at the bottom of the welding seam space 4, and welding quality defects are prone to occur. By deepening the depth of the welding seam space 4, the part of the welding filler that may have defects can be removed when the root is trimmed by machining in S4, and the welding quality of the welding root of the formed spherical shell structure 1 can be effectively ensured.

[0054] S3 is a process of welding work, and the welding seam of the spherical shell structure is smoothly welded by using the submerged arc automatic welding.

[0055] In an optional embodiment, as shown in Figure 3As shown, during the welding process, the lower spherical shell 12 is supported on the support 5, and an isolation structure 6 is arranged between the lower spherical shell 12 and the support 5. The preheating tool 7 is arranged on the top of the support 5 and is located above the weld space 4. By supporting the lower spherical shell 12 on the support 5 and providing a suitable mounting position for the preheating tool 7 through the support 5, the welding area of the spherical shell structure 1 can be preheated from the outside to the inside, ensuring the smooth progress of the submerged arc automatic welding. By adjusting the position of the preheating tool 7 and the heat accumulation effect inside the spherical shell structure 1, the preheating temperature of the welding position can be ensured to meet the manufacturing requirements, and the problem of difficult positioning of the preheating tool 7 inside the spherical shell structure 1 can be overcome.

[0056] In an optional embodiment, in S3, the preheating tool 7 is used to preheat the groove and both sides. After the welding is completed, stress relief heat treatment is directly performed, or after the welding is completed, the temperature is heated to 300-350℃, and after holding for at least 2h, the preheating temperature is maintained until the stress relief heat treatment is performed. In order to ensure the final welding quality, the spherical shell structure 1 prepared can meet the design and use requirements.

[0057] In an optional embodiment, the stress relief heat treatment can be performed in a heating furnace.

[0058] In an optional embodiment, after the welding is completed, the preheating tool 7 can be used to continue heating to 300-350℃, and holding for at least 2h to realize hydrogen removal treatment. After the hydrogen removal treatment, the stress relief heat treatment is performed in the furnace again, which can overcome the influence of the spherical shell structure 1 which cannot immediately enter the furnace for stress relief heat treatment on the welding quality.

[0059] In an optional embodiment, in S3, the continuous welding is performed by the submerged arc automatic welding, or when the welding work is interrupted, the preheating tool 7 is used to maintain the temperature of the weld seam at not less than the preheating temperature until the welding work is restarted. In order to complete the smooth welding of the entire weld space 4 by the submerged arc automatic welding, reduce the welding material consumption, ensure the weld seam quality, and improve the welding efficiency.

[0060] S4 is a process of machining the inner wall of the spherical shell structure 1 after the welding is completed, removing the first matching part 2, the second matching part 3, and the weld meat protruding from the inner wall of the spherical shell structure 1, to ensure the quality of the weld seam root.

[0061] In an optional embodiment, since the weld space 4 extends beyond the thickness L of the inner wall of the spherical shell structure 1, which is greater than or equal to the thickness of two layers of weld meat, during the root trimming in S4, the weld meat protruding from the spherical shell structure 1 can be removed. For example, the thickness of each layer of weld meat can be 2mm, and at least 4mm thick weld meat can be removed during the root trimming in S4, so that the quality of the weld seam root can meet the detection requirements.

[0062] In an optional embodiment, the mechanical processing for the root modification of the weld of the spherical shell structure 1 can be performed in a conventional mechanical processing manner, for example, by using a vertical lathe for removal processing, without the need for manual operation inside the spherical shell structure 1.

[0063] The welding forming method of the closed confined space spherical shell structure of the embodiment can make the assembly of the upper spherical shell 11 and the lower spherical shell 12 simple and fast, and improve the assembly efficiency, by setting the first matching part 2 and the second matching part 3 when the upper spherical shell 11 and the lower spherical shell 12 are prepared. Meanwhile, the weld space 4 with a closed root is formed after the combination of the upper spherical shell 11 and the lower spherical shell 12, and the weld space 4 can be filled by submerged arc automatic welding. After welding, only the removal of the first matching part 2 and the second matching part 3 is needed, without the need for additional root cleaning and welding action on the weld root, which can effectively ensure the quality of the weld root, and is conducive to further improving the welding efficiency.

[0064] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A welding and forming method for a confined space spherical shell structure, characterized in that, include: S1. Component preparation: Prepare a forged component including an upper spherical shell (11) and a lower spherical shell (12). The upper spherical shell (11) has a first mating part (2) protruding into the spherical shell structure (1) at the position corresponding to the root of the weld at the bevel to be welded. The lower spherical shell (12) has a second mating part (3) protruding into the spherical shell structure (1) at the position corresponding to the root of the weld at the bevel to be welded. The first mating part (2) and the second mating part (3) can be nested together. The upper spherical shell (11) is a cylindrical structure. The lower spherical shell (12) is provided with an assembly hole. The upper spherical shell (11) and the lower spherical shell (12) are assembled to form the spherical shell structure (1). The upper spherical shell (11) and the lower spherical shell (12) have reserved material allowances at the positions corresponding to the root of the weld at the spherical shell structure (1) to form the first mating part (2) and the second mating part (3). S2. Component assembly: Combine the upper spherical shell (11) and the lower spherical shell (12) to form a spherical shell structure (1), so that the first mating part (2) and the second mating part (3) abut against each other. The first mating part (2) includes a recessed platform, and the second mating part (3) includes a protrusion. The protrusion and the recessed platform are nested together. The protrusion is provided with an arc-shaped surface (31) at the position of the bottom surface of the corresponding weld space (4) to form a weld space (4) closed at the root of the weld. The bottom of the weld space extends beyond the inner wall of the spherical shell structure. S3. Welding of the weld seam: Welding of the weld seam space (4) is carried out by submerged arc automatic welding. S4. Root trimming: Remove the first mating part (2) and the second mating part (3) along the inner wall of the spherical shell structure (1) using mechanical processing. In S2, after the first mating part (2) and the second mating part (3) are combined, the thickness H in the depth direction of the weld space (4) satisfies: 6mm≤H≤8mm, the bottom of the weld space (4) extends beyond the inner wall of the spherical shell structure (1), and the thickness L of the weld space (4) extending beyond the inner wall of the spherical shell structure (1) is greater than or equal to the thickness of the two layers of weld. In S3, the lower spherical shell (12) is supported on the support (5). An isolation structure (6) is provided between the lower spherical shell (12) and the support (5). A preheating fixture (7) is provided on the top of the support (5). The preheating fixture (7) is located above the weld space (4). The bevel and both sides are preheated by the preheating fixture (7). After welding, stress relief heat treatment is performed directly. Alternatively, after welding, the temperature is heated to 300-350℃ and kept at the temperature for at least 2 hours. The preheating temperature is maintained until stress relief heat treatment is performed.

2. The welding and forming method for a confined space spherical shell structure according to claim 1, characterized in that, In S3, continuous welding is carried out by submerged arc automatic welding, or, when the welding work is interrupted, the temperature of the weld is kept not lower than the preheating temperature by using a preheating fixture (7) until the welding work is restarted.

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