Ultra-large narrow and long steel structural part welding method capable of reducing welding deformation

Abstract

According to the ultra-large narrow and long steel structural part welding method capable of reducing welding deformation, the total weight of structural parts is not lower than 20 tons, the thicknesses of top plates, bottom plates and vertical plates are all not smaller than 100 mm, two sets of steel structural parts can be assembled in a back-to-back mode through connecting plates, the welding process of the bottom plates and the top plates on the two sides is symmetrically conducted, the welding deformation is offset, and the welding quality is improved. The two structural parts can be annealed at the same time, and annealing deformation is reduced; welding a backing on the back surface of the groove of the vertical plate to ensure that enough gaps are formed between the vertical plate and the top plate and between the vertical plate and the bottom plate, so that a welding seam can be subjected to full penetration welding from the outer side; during assembly, the process blocks are welded in advance, backing welding of CO2 gas shielded welding is conducted, then the process blocks are dismantled, submerged-arc welding is conducted multiple times subsequently, and when the depth of a welding seam of the vertical plate and the top plate is smaller than the single-time welding depth of submerged-arc welding, the top plate is straightened through flames at the position, corresponding to the welding seam, of the outer side surface of the top plate, and the top plate is baked to be flanged; reversible deformation is prefabricated, and the welding quality is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of welding of super-large narrow and long steel structural parts, and in particular to a welding method of super-large narrow and long steel structural parts for reducing welding deformation. Background Art

[0002] In some large mechanical devices, ultra-large narrow and long steel structures with welded structures are required. Such structures include a top plate, a bottom plate and two vertical plates. The two sides of the vertical plates are welded to the top plate and the bottom plate respectively. The thickness of the top plate, the bottom plate and the vertical plates are not less than 100 mm, and the total weight of the structures is not less than 20 tons. That is, the length of the top plate, the bottom plate and the vertical plates are all long. Therefore, not only the length of the weld is large, but also the depth of the groove is large. There are the following welding difficulties: 1. There are a large number of steel structures, each of which has 4 main welds. During the welding process, it is necessary to continuously flip the structure to achieve welding of all welds. How to reduce the number of flips and improve production efficiency has become a manufacturing difficulty; 2. The steel structure is a narrow and long structure with a plate thickness of not less than 100mm. The weld filling volume is large, which is prone to welding deformation after welding, resulting in lateral bending of the product, which is difficult to correct; 3. Since all welds are required to be fully penetrated, and the product structure is box-shaped, the internal space is small and welding cannot be achieved. The groove form is a single-sided groove, and full penetration of the weld cannot be achieved; 4. The groove depth is not less than 100mm, and multiple layers and multiple passes of welding are required to fill the groove. The quality of the base weld is particularly important. Conventional means of spot welding the steel structure on the groove surface are difficult to ensure the quality of the weld; 5. The grooves of the steel structure are all on the vertical plates. During the welding process, the top plate or the bottom plate will deform toward the groove, resulting in excessive flatness; The prior art only has welding experience for smaller products of the same structure. Therefore, for such super-large components, it is difficult to effectively control welding deformation and ensure full penetration welding of the weld under the conditions of groove welding and large weld filling volume. Summary of the invention

[0003] The purpose of the present invention is to provide a super-large narrow and long steel structure welding method which can reduce welding deformation and ensure the welding quality of the super-large narrow and long steel structure.

[0004] The technical solution adopted by the present invention to solve the above technical problems is: a welding method for an ultra-large narrow and long steel structure member with reduced welding deformation, wherein the ultra-large narrow and long steel structure member comprises a top plate, a bottom plate and two vertical plates, the top plate, the bottom plate and the vertical plates are rectangular flat plates parallel to each other in length direction, the surfaces of the top plate and the bottom plate on one side along the thickness direction are arranged oppositely and parallel to each other, the vertical plate is located between the top plate and the bottom plate, the two vertical plates are arranged at intervals along the width direction of the top plate and the bottom plate, the width direction of the vertical plate is perpendicular to the width direction of the top plate and the bottom plate, the two sides of the vertical plate along the width direction are respectively welded to the side surfaces of the top plate and the bottom plate opposite to each other in the thickness direction, the thickness of the top plate, the bottom plate and the vertical plate are not less than 100 mm, the total weight of the ultra-large narrow and long steel structure member is not less than 20 tons, and the welding method comprises the following steps: Step 1: Process single-sided V-shaped grooves on both sides of the vertical plate in the thickness direction, with the grooves on both sides facing the same direction. Then, weld two gaskets on the back side of the groove of the vertical plate. The two gaskets are close to the two sides of the vertical plate in the thickness direction, and the length direction of the gasket is parallel to the length direction of the vertical plate. The two ends of the gasket in the length direction extend from the two ends of the vertical plate in the length direction. One side of the gasket in the width direction is the assembly surface for being placed on the top plate or the bottom plate. The assembly surface extends 5-6mm from the edge of the back side of the groove in the thickness direction of the vertical plate. Step 2: Lay the bottom plate flat, and then place two vertical plates vertically on the surface of the bottom plate, respectively, so that the gasket assembly surfaces of the two vertical plates facing downwards are respectively fitted with the surface of the bottom plate, and then assemble multiple process blocks between the bottom plate and the two vertical plates, and the multiple process blocks are spaced apart along the length direction of the vertical plates and the bottom plate, one side of the process block is fitted and welded with the surface of the bottom plate, and the other side of the process block is fitted and welded with the surface of the vertical plate located on the positive side of the groove; Then, the top plate is placed flat on the upward side of the two vertical plates, so that the gasket assembly surfaces on the upward side of the two vertical plates are respectively fitted with the surface of the top plate, and then a plurality of process blocks are respectively assembled between the top plate and the two vertical plates, and the plurality of process blocks are spaced and distributed along the length direction of the vertical plates and the top plate, one side of the process block is fitted and welded with the surface of the top plate, and the other side of the process block is fitted and welded with the surface of the vertical plate located on the positive side of the groove, so as to obtain a preassembled structural member; Step 3: Weld lifting ears on the preassembled structural parts. After lifting the two preassembled structural parts, make the bottom plates of the two preassembled structural parts fit relatively to each other on the side away from the top plate, and ensure that the sides of the two bottom plates in the width and thickness directions are aligned respectively. Then, weld a plurality of connecting plates on the sides of the two bottom plates in the width and thickness directions respectively, and form the two preassembled structural parts into an integral structure through the connecting plates. Step 4: Lift the two pre-assembled structural parts of the overall structure, place the two bottom plates vertically along the width direction, and then use CO 2Gas shielded welding is used to perform the bottom welding of the weld between the upper vertical plate and the bottom plate. The weld position is preheated to 80-100℃ before welding, the weld depth is 8-12mm, and the welding processes of the two pre-assembled structural parts are ensured to be symmetrical. Then, the weld is welded by CO 2 Perform symmetrical bottom welding on the welds of the vertical plate and the top plate on the upper side by gas shielded welding, and remove the process blocks corresponding to the weld positions after the bottom welding; After the four welds are welded, the two pre-assembled structural parts are lifted and turned over so that the remaining four welds face upwards, and symmetrical welding is performed in the same order and the process blocks are removed; Step 5: Keep the bottom plates of the two preassembled structural members in a vertical position along the width direction, and perform symmetrical filling welding on the welds of the upper side vertical plate and the bottom plate by submerged arc welding. The weld depth of a single welding is 15-25mm. Then, perform symmetrical filling welding on the welds of the upper side vertical plate and the top plate by submerged arc welding. After reaching the weld depth of a single welding, lift and flip the two preassembled structural members so that the remaining four welds face upwards, and perform symmetrical filling welding in the same order. After the first-time filling welding of the eight welds is completed in sequence, the two pre-assembled structural parts are hoisted and turned over again, and the next filling welding is continued until the remaining depth of all welds is less than the weld depth of a single welding; Step 6: After the filling welding is completed, flame correction is performed on the side of the top plate of the two pre-assembled structural parts away from the bottom plate. The flame correction method causes reverse deformation in the correction area, which is a long strip area corresponding to the weld position. The reverse deformation causes the edges on both sides of the top plate in the width direction to bend and flange relative to the middle area in the direction away from the bottom plate. Then, the bottom plates of the two preassembled structural members are kept in a vertical position along the width direction, and the welds between the vertical plate on the upper side and the bottom plate are symmetrically covered by submerged arc welding, and the welds between the vertical plate on the upper side and the top plate are symmetrically covered by submerged arc welding. Then, the two preassembled structural members are lifted and turned over so that the remaining four welds face upward, and symmetrical covering welding is performed in the same order; Step 7: After the cover welding is completed, the two pre-assembled structural parts are annealed at the same time, and then the connecting plate is removed to separate the two pre-assembled structural parts, thus completing the welding process of the two super-large narrow and long steel structural parts.

[0005] Preferably, the gasket is a rectangular flat plate. During the assembly in step 2, lines are first drawn on the surfaces of the top plate and the bottom plate, and the drawn area is the placement area of ​​the gasket assembly surface.

[0006] Preferably, the correction area is a rectangular strip area, one side edge of the correction area is located between the edge of the vertical plate and the middle area of ​​the top plate, and the other side edge of the correction area is the edge of the top plate along the width direction.

[0007] According to the above technical solution, the beneficial effects of the present invention are: 1. The two sets of steel structures can be assembled back to back through the connecting plate. The two structures can be flipped at the same time through the lifting lugs. Therefore, the bottom plate welds of the two structures can be welded at the same time, and the welding process of the bottom plates and top plates on both sides is carried out symmetrically, so that the welding deformation of the steel structures on both sides offsets each other, and the two structures can be annealed at the same time. The two structures are symmetrically constrained to reduce annealing deformation.

[0008] 2. A single V-shaped groove is used on the vertical plate, and a gasket is welded on the back of the groove. The gasket is in contact with the top plate and the bottom plate, thereby ensuring that there is sufficient gap between the vertical plate and the top plate and the bottom plate, so that the weld can be fully penetrated from the outside of the structural member.

[0009] 3. When assembling the vertical plate, place the process block at the outside of the corner between the vertical plate, top plate and bottom plate. First, weld the process block to the vertical plate, top plate and bottom plate respectively, and then perform the bottom welding on the welds between the vertical plate, top plate and bottom plate. Since multiple process blocks are arranged at intervals, it will not affect CO 2 During the gas shielded welding, the process block can be removed after the base welding, so as not to affect the subsequent submerged arc welding.

[0010] 4. When the weld depth between the vertical plate and the top plate is less than the single welding depth of submerged arc welding, use flame to correct the top plate at the position corresponding to the weld on the outer surface of the top plate, bake the top plate to flanging, and pre-form reverse deformation. The reverse deformation can offset the hook of the top plate caused by welding deformation. Therefore, after the final cover welding of submerged arc welding, the welding deformation that would have been caused by submerged arc welding can be eliminated to ensure the welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the main view of a narrow and long steel structure; Figure 2 It is a side view schematic diagram of a narrow and long steel structure; Figure 3 The figure is a schematic diagram of the assembly of the gasket; Figure 4 It is the assembly diagram of the process block; Figure 5 A schematic diagram of back-to-back assembly via a connecting plate; Figure 6 Schematic diagram of the correction area when looking down at the top plate.

[0012] Markings in the figure: 1. top plate, 2. vertical plate, 3. bottom plate, 4. pad, 5. process block, 6. connecting plate, 7. correction area. DETAILED DESCRIPTION

[0013] With reference to the accompanying drawings, the specific implementation is as follows: A welding method for ultra-large narrow and long steel structure parts with reduced welding deformation, such as Figure 1 , 2 As shown, the super-large narrow and long steel structure comprises a top plate 1, a bottom plate 3 and two vertical plates 2. The top plate 1, the bottom plate 3 and the vertical plates 2 are rectangular flat plates parallel to each other in the length direction. The surfaces of the top plate 1 and the bottom plate 3 on one side in the thickness direction are arranged opposite to each other and are parallel to each other. The vertical plate 2 is located between the top plate 1 and the bottom plate 3. The two vertical plates 2 are arranged at intervals along the width direction of the top plate 1 and the bottom plate 3. The width direction of the vertical plates 2 is perpendicular to the width direction of the top plate 1 and the bottom plate 3. The two sides of the vertical plates 2 along the width direction are respectively welded to the side surfaces of the top plate 1 and the bottom plate 3 opposite to each other in the thickness direction. The thickness of the top plate 1, the bottom plate 3 and the vertical plates 2 are not less than 100 mm. The total weight of the super-large narrow and long steel structure is not less than 20 tons.

[0014] The welding method comprises the following steps: Step 1: Process single-sided V-shaped grooves on both sides of the thickness direction of the vertical plate 2, with the grooves on both sides facing the same direction, and then Figure 3 As shown, two gaskets 4 are welded on the back surface of the groove of the vertical plate 2. The gasket 4 is a rectangular flat plate. The two gaskets 4 are respectively close to the two sides of the vertical plate 2 along the thickness direction. The length direction of the gasket 4 is parallel to the length direction of the vertical plate 2. The two ends of the gasket 4 along the length direction extend from the two ends of the vertical plate 2 along the length direction respectively. One side of the gasket 4 along the width direction is an assembly surface for being placed on the top plate 1 or the bottom plate 3. The assembly surface extends 5-6mm from the edge of the back side of the groove along the thickness direction of the vertical plate 2.

[0015] Step 2: Lay the bottom plate 3 flat, and then place the two vertical plates 2 vertically on the surface of the bottom plate 3, so that the assembly surfaces of the gaskets 4 on the downward side of the two vertical plates 2 are respectively fitted with the surface of the bottom plate 3, and then assemble multiple process blocks 5 between the bottom plate 3 and the two vertical plates 2, and the multiple process blocks 5 are spaced apart along the length direction of the vertical plates 2 and the bottom plate 3. One side of the process block 5 is fitted and welded to the surface of the bottom plate 3, and the other side of the process block 5 is fitted and welded to the surface of the vertical plate 2 on the positive side of the groove. The welding position of the process block 5 is as follows: Figure 4 shown.

[0016] Then, the top plate 1 is placed flat on the upward side of the two vertical plates 2, so that the assembly surfaces of the gaskets 4 on the upward sides of the two vertical plates 2 are respectively fitted with the surfaces of the top plate 1, and then a plurality of process blocks 5 are respectively assembled between the top plate 1 and the two vertical plates 2. The plurality of process blocks 5 are spaced apart along the length direction of the vertical plates 2 and the top plate 1, one side of the process block 5 is fitted and welded to the surface of the top plate 1, and the other side of the process block 5 is fitted and welded to the surface of the vertical plate 2 on the positive side of the groove, to obtain a preassembled structural component.

[0017] During assembly, the surfaces of the top plate 1 and the bottom plate 3 may be marked in advance, and the marked area is the placement area of ​​the assembly surface of the gasket 4, which is convenient for the placement of the vertical plate 2.

[0018] Step 3: Weld the lifting lugs on the preassembled structural parts. After lifting the two preassembled structural parts, make the bottom plates 3 of the two preassembled structural parts fit relatively to each other on the side away from the top plate 1, and ensure that the sides of the two bottom plates 3 along the width and thickness directions are aligned respectively. Then, weld a plurality of connecting plates 6 on the sides of the two bottom plates 3 along the width and thickness directions respectively. Figure 5 As shown, the connecting plate 6 is a rectangular flat plate, and the two preassembled structural members are connected to form an integral structure through the connecting plate 6.

[0019] Step 4: Lift the two pre-assembled structural parts of the overall structure, place the two bottom plates 3 vertically along the width direction, and then use CO 2 Gas shielded welding is used to perform the bottom welding of the weld between the upper side vertical plate 2 and the bottom plate 3. The weld position is preheated to 80-100℃ before welding, the weld depth is 8-12mm, and the welding processes of the two pre-assembled structural parts are ensured to be symmetrical to each other. Then, CO 2 The gas shielded welding is used to perform symmetrical bottom welding on the welds between the vertical plate 2 and the top plate 1 on the upper side, and the process block 5 corresponding to the weld position after the bottom welding is removed.

[0020] After the base welding of the four welds is completed, the two preassembled structural members are lifted and turned over so that the remaining four welds face upward, and symmetrical base welding is performed in the same order and the process block 5 is removed.

[0021] Step 5. Keep the bottom plates 3 of the two preassembled structural members in a vertical position along the width direction, and perform symmetrical filling welding on the welds between the vertical plate 2 and the bottom plate 3 on the upper side by submerged arc welding. The weld depth of a single welding is 15-25mm. Then, perform symmetrical filling welding on the welds between the vertical plate 2 and the top plate 1 on the upper side by submerged arc welding. After reaching the weld depth of a single welding, lift and flip the two preassembled structural members so that the remaining four welds face upward, and perform symmetrical filling welding in the same order.

[0022] After the first filling welding of the eight welds is completed in sequence, the two preassembled structural components are lifted and turned over again, and the next filling welding is continued until the remaining depth of all welds is less than the weld depth of a single welding.

[0023] Step 6: After the filling welding is completed, flame correction is performed on the side of the top plate 1 of the two pre-assembled structural parts away from the bottom plate 3. The correction area 7 is deformed by flame correction. The correction area 7 is a long strip area corresponding to the weld position, such as Figure 6 As shown, Figure 6 The dotted line in the figure represents the weld position of the vertical plate 2, one side edge of the correction area 7 is located between the edge of the vertical plate 2 and the middle area of ​​the top plate 1, and the other side edge of the correction area 7 is the edge of the top plate 1 along the width direction. Through reverse deformation, the two side edges of the top plate 1 in the width direction are bent and flanged relative to the middle area in the direction away from the bottom plate 3.

[0024] Then, keep the bottom plates 3 of the two preassembled structural components in a vertical position along the width direction, and perform symmetrical cover welding on the welds between the vertical plate 2 and the bottom plate 3 on the upper side by submerged arc welding, and then perform symmetrical cover welding on the welds between the vertical plate 2 and the top plate 1 on the upper side by submerged arc welding, and then lift and flip the two preassembled structural components so that the remaining four welds face upward, and perform symmetrical cover welding in the same order.

[0025] Step 7: After welding, annealing is required to avoid stress concentration. Since annealing is a heat treatment process, if the two steel structure connecting plates are removed, the annealing thermal deformation of the single steel structure is large and the deformation is uncontrolled. Therefore, the two pre-assembled structural parts are annealed at the same time to constrain each other and effectively control the annealing deformation. After annealing, the connecting plate 6 is removed to separate the two pre-assembled structural parts, and the flatness and other dimensions are corrected to meet the requirements.

Claims

1. A method for welding an ultra-large narrow and long steel structure for reducing welding deformation, the ultra-large narrow and long steel structure comprising a top plate (1), a bottom plate (3) and two vertical plates (2), the top plate (1), the bottom plate (3) and the vertical plates (2) being rectangular flat plates parallel to each other in length direction, the surfaces of the top plate (1) and the bottom plate (3) on one side in thickness direction are arranged opposite to each other and are parallel to each other, the vertical plate (2) is located between the top plate (1) and the bottom plate (3), the two vertical plates (2) are arranged at intervals along the width direction of the top plate (1) and the bottom plate (3), the width direction of the vertical plate (2) is perpendicular to the width direction of the top plate (1) and the bottom plate (3), the two sides of the vertical plate (2) along the width direction are respectively welded to the side surfaces of the top plate (1) and the bottom plate (3) opposite to each other in thickness direction, the thickness of the top plate (1), the bottom plate (3) and the vertical plates (2) are not less than 100 mm, the total weight of the ultra-large narrow and long steel structure is not less than 20 tons, and the method is characterized in that: The welding method comprises the following steps: Step 1: Processing single-sided V-shaped grooves on both sides of the vertical plate (2) in the thickness direction, with the grooves on both sides facing the same direction, and then welding two gaskets (4) on the back side of the groove of the vertical plate (2), the two gaskets (4) are respectively close to the two sides of the vertical plate (2) in the thickness direction, the length direction of the gasket (4) is parallel to the length direction of the vertical plate (2), and the two ends of the gasket (4) in the length direction extend from the two ends of the vertical plate (2) in the length direction respectively, and one side of the gasket (4) in the width direction is an assembly surface for being placed on the top plate (1) or the bottom plate (3), and the assembly surface extends 5-6 mm from the edge of the back side of the groove in the thickness direction of the vertical plate (2); Step 2: Lay the bottom plate (3) flat, and then place the two vertical plates (2) vertically on the surface of the bottom plate (3) respectively, so that the assembly surfaces of the gaskets (4) on the downward side of the two vertical plates (2) are respectively fitted with the surface of the bottom plate (3), and then assemble a plurality of process blocks (5) between the bottom plate (3) and the two vertical plates (2), the plurality of process blocks (5) are spaced apart along the length direction of the vertical plates (2) and the bottom plate (3), one side of the process block (5) is fitted and welded to the surface of the bottom plate (3), and the other side of the process block (5) is fitted and welded to the surface of the vertical plate (2) located on the positive side of the groove; Then, the top plate (1) is placed flat on the upward side of the two vertical plates (2), so that the assembly surfaces of the gaskets (4) on the upward side of the two vertical plates (2) are respectively fitted with the surface of the top plate (1), and then a plurality of process blocks (5) are respectively assembled between the top plate (1) and the two vertical plates (2), the plurality of process blocks (5) are spaced apart along the length direction of the vertical plates (2) and the top plate (1), one side of the process block (5) is fitted and welded with the surface of the top plate (1), and the other side of the process block (5) is fitted and welded with the surface of the vertical plate (2) located on the positive side of the groove, so as to obtain a preassembled structural component; Step 3: Welding lifting ears on the pre-assembled structural parts, lifting the two pre-assembled structural parts, making the surfaces of the bottom plates (3) of the two pre-assembled structural parts away from the top plate (1) relatively fit together, and ensuring that the side surfaces of the two bottom plates (3) along the width and thickness directions are aligned respectively, and then welding a plurality of connecting plates (6) on the side surfaces of the two bottom plates (3) along the width and thickness directions respectively, so that the two pre-assembled structural parts form an integral structure through the connecting plates (6); Step 4: hoist the two preassembled structural members of the overall structure so that the two bottom plates (3) are placed vertically in the width direction, and then the weld seam between the upper side vertical plate (2) and the bottom plate (3) is welded with a bottoming weld by CO2 gas shielded welding. The weld position is preheated to 80-100° C. before welding, and the weld depth is 8-12 mm. The welding processes of the two preassembled structural members are ensured to be symmetrical to each other. Then, the weld seam between the upper side vertical plate (2) and the top plate (1) is welded with a bottoming weld symmetrically by CO2 gas shielded welding, and the process block (5) corresponding to the weld position after the bottoming welding is removed. After the four weld seams are welded, the two pre-assembled structural members are lifted and turned over so that the remaining four weld seams face upwards, and symmetrical welding is performed in the same order and the process block (5) is removed; Step 5: Keep the bottom plates (3) of the two preassembled structural members in a vertical position along the width direction, and perform symmetrical filling welding on the welds of the upper side vertical plate (2) and the bottom plate (3) by submerged arc welding, with the weld depth of a single welding being 15-25 mm. Then, perform symmetrical filling welding on the welds of the upper side vertical plate (2) and the top plate (1) by submerged arc welding. After reaching the weld depth of a single welding, lift and flip the two preassembled structural members so that the remaining four welds face upward, and perform symmetrical filling welding in the same order. After the first-time filling welding of the eight welds is completed in sequence, the two pre-assembled structural parts are hoisted and turned over again, and the next filling welding is continued until the remaining depth of all welds is less than the weld depth of a single welding; Step 6: After the filling welding is completed, flame correction is performed on the side of the top plate (1) of the two pre-assembled structural parts away from the bottom plate (3), and the correction area (7) is reversely deformed by flame correction. The correction area (7) is a long strip area corresponding to the position of the weld. The reverse deformation causes the edges on both sides of the top plate (1) in the width direction to be bent and flanged relative to the middle area in a direction away from the bottom plate (3); Then, the bottom plates (3) of the two pre-assembled structural members are kept in a vertically placed state along the width direction, and the weld seams between the vertical plate (2) and the bottom plate (3) on the upward side are symmetrically covered by submerged arc welding, and the weld seams between the vertical plate (2) and the top plate (1) on the upward side are symmetrically covered by submerged arc welding, and then the two pre-assembled structural members are lifted and turned over so that the remaining four weld seams face upward, and symmetrically covered by welding is performed in the same order; Step 7: After the cover welding is completed, the two pre-assembled structural members are annealed at the same time, and then the connecting plate (6) is removed to separate the two pre-assembled structural members, thus completing the welding process of the two super-large narrow and long steel structural members.

2. A method for welding ultra-large narrow and long steel structures to reduce welding deformation according to claim 1, characterized in that: The gasket (4) is a rectangular flat plate. During the assembly in step 2, lines are first drawn on the surfaces of the top plate (1) and the bottom plate (3), and the drawn area is the placement area of ​​the gasket (4) assembly surface.

3. A method for welding ultra-large narrow and long steel structures with reduced welding deformation according to claim 1, characterized in that: The correction area (7) is a rectangular strip area, one side edge of the correction area (7) is located between the edge of the vertical plate (2) and the middle area of ​​the top plate (1), and the other side edge of the correction area (7) is the edge of the top plate (1) along the width direction.

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