一种船舶分段建造激光复合焊接工艺

Abstract

本发明涉及焊接技术领域，公开一种船舶分段建造激光复合焊接工艺，步骤：先进行分段拼板缝通过激光电弧复合焊接设备进行正面焊缝的焊接，形成大的分段板片；拼板缝正面焊缝焊接完成后，采用激光电弧复合焊接设备进行纵向骨材的装配焊接；纵向骨材完成后，对横向T排结构的角焊缝焊接，采用全自动机器人药芯焊丝气保焊工艺，其他小支撑腹板结构件，采用半自动药芯焊丝气保焊完成焊接；分段翻身后，采用双丝埋弧焊工艺对拼板缝的反面焊缝进行焊接。用于船舶分段建造的厚板焊接，用于厚板焊接可大幅提高焊接生产效率，分段制作过程中可显著减少焊接变形及焊接应力，焊接质量高，同时极大节省焊接耗材成本，船舶分段建造的厚板焊接具有较大优势。

Description

Technical Field

[0001] This invention relates to the field of welding technology, specifically a laser composite welding process for ship section construction. Background Technology

[0002] With the development of the global shipping industry, the demand for shipbuilding is increasing. During the segmented construction of ships, welding involves a large volume of production, with dense weld seams, and welding time accounts for a significant portion of the total time spent on welding. Furthermore, for full-penetration welds such as plate joints, the weld quality requirements are high, generally requiring post-weld inspection.

[0003] Currently, for the welding of thick plates in the segmented construction of ships, shipyards commonly use submerged arc welding (SAW) or fuel cell welding (FCB) for butt welding of sectional plates, and CO2 gas shielded welding for longitudinal reinforcement and T-row fillet welds. SAW offers stable weld quality for thick plate sectional welding, but requires multiple layers and passes, resulting in relatively low welding efficiency. FCB welding is highly efficient, but prone to welding cracks that affect weld quality, and due to its single-sided welding characteristics, it results in significant post-weld deformation, generally requiring heat straightening. CO2 gas shielded welding for longitudinal reinforcement and T-row fillet welds has relatively low welding efficiency.

[0004] Document ZL202211297009 discloses a method for laser composite welding of thin plates with a coating. The method involves providing two plates to be welded, coating at least the upper and lower surfaces of their opposite edges with a high-temperature resistant workshop primer of a different color than the plates. An optical camera tracking device tracks and locates the weld seam, using the color difference between the gap between the two plates and the high-temperature resistant workshop primer to determine the weld seam position. Laser composite welding is then used to weld the two plates together. This method has low production efficiency and increases welding deformation and stress.

[0005] Therefore, a new technical solution is needed to solve the above-mentioned technical problems. Summary of the Invention

[0006] To address the aforementioned problems, thick plate welding for ship section construction offers significant advantages. This invention discloses a laser-based composite welding process for ship section construction, comprising the following steps: [The process is described in the original text, but the provided excerpt ends here.]

[0007] Step a: First, the segmented plate seams are welded using laser-arc hybrid welding equipment to form large segmented plates.

[0008] Step 1: Preparation of the bevel joint of the splicing plates: Using an I-type bevel, the two large plates placed on the steel platform are automatically milled to process the bevel. The circular milling cutter is in the middle of the two large plates and processes the two bevel edges at the same time. After the milling is completed, the plates are automatically assembled and aligned. The two large plates are brought close together and pressed tightly to ensure that the gap between the joints is no more than 1mm. A hydraulic piano key device is used to press and fix them.

[0009] Step 2: Preparation before welding the panel seams: Check the laser protective lens to ensure it is clean and free of contamination; check the welding shielding gas and verify the position of the laser head, the position of the MAG welding torch, and the filament spacing on the reference table;

[0010] Step 3: Laser welding positioning of panel seams: Positioning welding is performed using pure laser welding;

[0011] Step 4: Laser-MAG hybrid welding of the front weld seam of the splicing plate: The front weld seam of the splicing plate is welded using laser-MAG hybrid welding technology;

[0012] Step b: After the welding of the front weld of the splice joint is completed, the longitudinal skeleton is assembled and welded using laser-arc hybrid welding equipment;

[0013] Step 1: Longitudinal rib assembly: Mechanical positioning, hydraulic clamping fixture to press the ribs, the ribs and the base plate close together and tightly, ensuring that the joint gap is no more than 1mm, and hydraulic lifting fixture to perform reverse deformation pre-bending treatment on the base plate.

[0014] Step 2: Preparation for longitudinal fillet welds: Check the laser protective lens to ensure it is clean and free of contamination; check the welding shielding gas and verify the laser head position, MAG welding torch position, and filament spacing on the reference table;

[0015] Step 3: Laser-MAG composite welding of longitudinal fillet welds: Double-sided symmetrical welding is performed using laser-MAG composite welding technology, which involves a double-sided welding gun and a laser head.

[0016] Step c: After the longitudinal skeleton is completed, the fillet welds of the transverse T-row structure are welded using a fully automated robotic flux-cored wire gas shielded welding process. Other small support web structure components are welded using a semi-automatic flux-cored wire gas shielded welding process.

[0017] Step d: After the sections are flipped over, the reverse side of the joint is welded using a double-wire submerged arc welding process.

[0018] Preferably, in step a, the laser beam and the tip of the welding wire are aligned with the plate seam, the laser head is perpendicular to the plate, the MAG welding gun is at a 45° angle to the plate and is in a dragging arc posture, the length of the positioning weld in step 3 is 300-500mm, and the number of positioning welds for each plate seam is not less than 3; the laser power of the positioning weld is 5~8KW, the defocusing amount is -5~-8mm, and the welding speed is 3~4m / min;

[0019] Preferably, in step b, the laser head is at a 25° angle to the base plate, the MAG welding gun is at a 45° angle to the base plate and is in a dragging arc posture, the laser beam is 1~2mm above the intersection of the base plate and the vertical plate, and the tip of the welding wire is at the intersection of the base plate and the vertical plate, at which time the extension length of the welding wire is 22mm.

[0020] Preferably, step two in step b uses an Ar-CO2 mixture with an Ar to CO2 ratio of 92:8 and a flow rate of 40~50 L / min.

[0021] Preferably, in step b, the spacing between the double-sided welding torches in step three is 100~200mm, and the welding parameters used are as follows: laser power is 4~6KW, defocusing amount is 0~-2mm, and filament distance is 0~2mm.

[0022] Preferably, the MAG welding current is 250~280A, the welding voltage is 28~32V, the wire feed speed is 10~12m / min, and the welding speed is 2.5~3.5m / min. The laser-MAG hybrid welding uses a solid welding wire with a diameter of 1.2~1.4mm, which is suitable for high-speed laser hybrid welding. The selected welding wire deposited metal composition is: C, 0.04~0.08%; Si, 0.6~1.2%; Mn, 1.3~1.6%; P, <0.020%; S, <0.015%; Ni, 0.2~0.8%.

[0023] Preferably, step d, the dual-wire submerged arc welding process, uses a submerged arc welding wire with a diameter of 4.0~5.0mm. The selected welding wire and flux have the following molten metal composition: C, 0.01~0.04%; Si, 0.2~0.4%; Mn, 1.2~2.0%; P, <0.020%; S, <0.015%; Cr, 0.01~0.05%; Mo, 0.01~0.03%; Ni, 0.3~1.0%.

[0024] By adopting the above technical solution, the mechanical properties of the welding material are stable under the condition of double-wire high heat input welding.

[0025] Preferably, the laser-arc hybrid welding equipment includes a fiber laser and a pulsed welding power source. The laser-arc hybrid method is that the MAG welding torch is in front and the laser head is behind. The laser head and the MAG welding torch move in a straight line without oscillation.

[0026] Preferably, the dual-wire submerged arc welding equipment used in step d includes two welding power sources, AC and DC. The two welding wires are arranged longitudinally, with the front wire tilted forward by 8~9° and the rear wire tilted backward by 15°. The spacing between the welding wires is 20-30mm. The two welding wires maintain the same straightness with the center of the plate seam and share a common molten pool during welding.

[0027] Preferably, the welding parameters used in step d are as follows: the front wire is DC, the welding current is 1000~1100A, and the welding voltage is 32~35V; the rear wire is AC, the welding current is 800~900A, the welding voltage is 38~40V, and the welding speed is 0.9~1.2m / min.

[0028] The advantages of this invention are: 1. It greatly improves the welding efficiency of thick plate splicing in ship sections. It does not require beveling and adopts a double-sided single-pass welding process. The maximum thickness can reach 30mm. Moreover, the welding process adopted is fast. The maximum welding speed of the front laser-MAG composite welding process can reach 2.5m / min, and the maximum welding speed of the reverse double-wire submerged arc welding process can reach 1.2m / min, which greatly improves the production efficiency of thick plate splicing welding.

[0029] 2. Significantly improves the welding efficiency of longitudinal fillet welds. The laser-MAG composite welding process is used for double-sided symmetrical welding, and the welding speed can reach up to 3.5m / min, which is 4 to 7 times that of ordinary gas shielded welding process, thus improving the production efficiency of longitudinal fillet welds.

[0030] 3. It greatly saves welding materials. Full penetration welding can be achieved for panels with a thickness of 30mm or less without beveling. The beveling size required for panels with a thickness of more than 30mm is also greatly reduced compared with ordinary welding processes, which greatly saves the welding materials that need to be filled and saves welding consumable costs.

[0031] 4. Minimal welding deformation and stable welding quality during segmented welding, saving on deformation correction costs. The front weld of the panel is welded using laser-MAG composite welding, resulting in low heat input and minimal welding deformation. The back weld is welded using double-wire submerged arc welding, performed after the longitudinal ribs, T-bars, and other structural components are welded, providing significant constraint on the weld joint and thus minimizing welding deformation. Before the longitudinal rib fillet welds, a hydraulic lifting fixture is used to pre-bend the base plate to reduce deformation, further minimizing longitudinal rib fillet weld deformation.

[0032] 5. Optimize welding material matching. Laser-MAG hybrid welding selects solid welding wire with appropriate alloy composition, which is suitable for high-speed laser welding and ensures the welding processability and mechanical properties of the weld joint under high-speed welding conditions. The submerged arc welding wire and flux used in dual-wire submerged arc welding are alloyed and reinforced, and Ni element is added at 0.3~1.0%, which can ensure the low-temperature impact toughness of the weld joint under high heat input welding conditions, and can make the weld joint have good resistance to welding stress. Attached Figure Description

[0033] Figure 1 This is a flowchart of the welding process provided in an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram showing the position of the MAG welding gun and laser head relative to the weld seam in a laser-coated composite welded plate according to an embodiment of the present invention.

[0035] Figure 3 This is a schematic diagram showing the position of the MAG welding torch and laser head relative to the base plate and the upright plate in the laser composite welding of longitudinal ribs provided in an embodiment of the present invention.

[0036] in, Figure 2 and Figure 3 middle:

[0037] Plate seam 100; laser beam 200; MAG welding wire 300; base plate 400; vertical plate 500;

[0038] α1 Spacing between optical fibers; α2 Spacing between laser beam and base plate; β1 Angle between MAG welding wire and plate seam; β2 Angle between laser beam and base plate; β3 Angle between MAG welding wire and base plate. Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0040] like Figure 1 As shown, a laser composite welding process for segmented ship construction, with a panel thickness of 30mm and a longitudinal rib thickness of 15mm, includes the following steps:

[0041] Step a: First, the segmented plate seams are welded using laser-arc hybrid welding equipment to form large segmented plates.

[0042] Step 1: Preparation of the bevel joint of the splicing plates: Using an I-type bevel, the two large plates placed on the steel platform are automatically milled to process the bevel. The circular milling cutter is in the middle of the two large plates and processes the two bevel edges at the same time. After the milling is completed, the plates are automatically assembled and aligned. The two large plates are brought close together and pressed tightly to ensure that the gap between the joints is no more than 1mm. A hydraulic piano key device is used to press and fix them.

[0043] Step 2: Preparation before welding the plate seam: Check the laser protective lens to ensure it is clean and free of contaminants; check the welding shielding gas, verify the laser head position, MAG welding torch position, and wire spacing on the reference table; check the surface condition of the steel plate, and remove rust, paint, iron filings, and dust from the welding area and within a 20mm radius on both sides; check the surface condition of the welding wire, and replace any rusty welding wire; check the wire extension length to ensure it is within 20mm, as excessive length or short length will affect arc initiation and welding.

[0044] Step 3: Laser welding positioning of panel seams: Positioning welding is performed using pure laser welding;

[0045] Step 4: Laser-MAG hybrid welding of the front weld seam of the splicing plate: The front weld seam of the splicing plate is welded using laser-MAG hybrid welding technology;

[0046] Step b: After the welding of the front weld of the splice joint is completed, the longitudinal skeleton is assembled and welded using laser-arc hybrid welding equipment;

[0047] Step 1: Longitudinal rib assembly: Mechanical positioning, using hydraulic clamping fixtures to press the ribs, the ribs and the base plate are close together and tightly fitted, ensuring that the joint gap is no more than 1mm, the best is 0.5mm, and using hydraulic lifting fixtures to perform reverse deformation pre-bending treatment on the base plate;

[0048] Step 2: Preparation for longitudinal fillet welds: Check the laser protective lens to ensure it is clean and free of contamination; check the welding shielding gas and verify the laser head position, MAG welding torch position, and filament spacing on the reference table;

[0049] Step 3: Laser-MAG composite welding of longitudinal fillet welds: Double-sided symmetrical welding is performed using laser-MAG composite welding technology, which involves a double-sided welding gun and a laser head.

[0050] Step c: After the longitudinal skeleton is completed, the fillet welds of the transverse T-row structure are welded using a fully automated robotic flux-cored wire gas shielded welding process. Other small support web structure components are welded using a semi-automatic flux-cored wire gas shielded welding process.

[0051] Step d: After the sections are flipped over, the reverse side of the joint is welded using a double-wire submerged arc welding process.

[0052] In step a, the laser beam and welding wire are aligned with the front end of the plate seam. The laser head is perpendicular to the plate. The MAG welding gun is at a 45° angle to the plate and is in a dragging arc posture. In step 3, the locating weld length is 300mm, and the number of locating welds on each plate seam is no less than 3. The laser power for locating welding is 8KW, the defocusing amount is -8mm, and the welding speed is 3m / min.

[0053] In step b, the laser head is at a 25° angle to the base plate, the MAG welding gun is at a 45° angle to the base plate and is in a dragging arc posture, the laser beam is 2mm above the intersection of the base plate and the vertical plate, and the tip of the welding wire is at the intersection of the base plate and the vertical plate, at which time the extension length of the welding wire is 22mm.

[0054] Preferably, step two in step b uses an Ar-CO2 mixture with an Ar to CO2 ratio of 92:8 and a flow rate of 45 L / min.

[0055] In step b, the spacing between the double-sided welding torches in step three is 200mm, and the welding parameters used are as follows: laser power is 6KW, defocusing amount is -2mm, and filament distance is 2mm.

[0056] The MAG welding current is 280A, the welding voltage is 32V, the wire feed speed is 12m / min, and the welding speed is 3m / min. The laser-MAG hybrid welding uses a solid welding wire with a diameter of 1.2mm, which is suitable for high-speed laser hybrid welding. The selected welding wire deposited metal composition is: C, 0.05%; Si, 0.8%; Mn, 1.5%; P, 0.015%; S, 0.012%; Ni, 0.3%.

[0057] Step d, the twin-wire submerged arc welding process, uses a 5.0mm diameter submerged arc welding wire. The selected welding wire and flux have the following molten metal composition: C, 0.02%; Si, 0.3%; Mn, 1.6%; P, 0.016%; S, 0.01%; Cr, 0.03%; Mo, 0.03%; Ni, 0.6%. This welding material has stable mechanical properties under twin-wire high heat input welding conditions.

[0058] Laser-arc hybrid welding equipment includes a fiber laser and a pulsed welding power source. The laser-arc hybrid method is that the MAG welding torch is in front and the laser head is behind. The laser head and the MAG welding torch move in a straight line without oscillation.

[0059] When performing laser-assisted composite welding of the front weld seam of a plate joint, the positions of the MAG welding wire 300 and the laser beam 200 relative to the plate joint 100 are as follows: Figure 2 As shown, the leading edges of the laser beam 200 and the MAG welding wire 300 are aligned with the plate seam 100. The laser beam 200 is perpendicular to the plate. The angle β1 between the MAG welding wire 300 and the plate seam 100 is 45° and the wire is in a dragging arc posture. The spacing α1 between the laser wires is 2mm.

[0060] When performing laser-assisted composite welding of longitudinal fillet welds, the positions of the MAG welding wire 300 and the laser beam 200 relative to the base plate 400 and the vertical plate 500 are as follows: Figure 3As shown, the laser beam 200 forms a 25° angle β2 with the base plate 400, and the MAG welding wire 300 forms a 45° angle β3 with the base plate 400, exhibiting a dragging arc posture. The laser beam 200 is 2mm above the intersection of the base plate 400 and the vertical plate 500 at a distance α2. The tip of the MAG welding wire 300 is at the intersection of the base plate 400 and the vertical plate 500, with a wire extension length of 22mm at this point.

[0061] The twin-wire submerged arc welding equipment used in step d includes two welding power sources, AC and DC. The two welding wires are arranged longitudinally, with the front wire tilted forward at 9° and the rear wire tilted backward at 15°. The spacing between the welding wires is 30mm. The two welding wires maintain the same straightness with the center of the plate seam and share a common molten pool during welding.

[0062] The 30mm thick panel joint can be welded by welding one weld on each side, achieving full penetration.

[0063] The fillet weld of the 15mm thick longitudinal skeleton can be completed by welding one weld on each side. This fillet weld has a large penetration depth and a small weld leg, which is only 3mm.

[0064] By optimizing the laser hybrid welding process, full penetration welding can be achieved for plate thicknesses of 30mm and below without beveling using a double-sided single-pass welding process. This process is characterized by high welding speed and minimal welding deformation. Compared to conventional welding processes, the laser hybrid welding process for ship section construction provided by this invention significantly improves welding production efficiency for thick plate welding. During section fabrication, it significantly reduces welding deformation and stress, resulting in high welding quality and substantial savings in welding consumables costs. This invention offers significant advantages for thick plate welding in ship section construction.

[0065] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention; the objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and any modifications or variations of the embodiments of the present invention may be made without departing from the stated principles.

Claims

1. A laser composite welding process for ship section construction, characterized in that, Includes the following steps: Step a: First, the segmented plate seams are welded using laser-arc hybrid welding equipment to form large segmented plates. Step 1: Preparation of the bevel joint of the panels: I-type bevel is used. The circular milling cutter is placed between the two large panels to process the two bevel edges simultaneously. After the milling is completed, automatic assembly is performed. The two large panels are brought close together and pressed tightly to ensure that the joint gap is no more than 1mm. A hydraulic piano key device is used to press and fix them. Step 2: Preparation before welding the panel seams: Check the laser protective lens to ensure it is clean and free of contamination; check the welding shielding gas and verify the position of the laser head, the position of the MAG welding torch, and the filament spacing on the reference table; Step 3: Laser welding positioning of panel seams: Pure laser welding is used for positioning welding. The laser power for positioning welding is 5~8KW, the defocusing amount is -5~-8mm, and the welding speed is 3~4m / min. Step 4: Laser-MAG hybrid welding of the front weld seam of the splice plate: The front weld seam of the splice plate is welded using laser-MAG hybrid welding technology. The MAG welding current is 250~280A, the welding voltage is 28~32V, and the welding speed is 2.5~3.5m / min. Step b: After the welding of the front weld of the splice joint is completed, the longitudinal skeleton is assembled and welded using laser-arc hybrid welding equipment; Step 1: Longitudinal rib assembly: Mechanical positioning, hydraulic clamping fixture to press the ribs, the ribs and the base plate close together and tightly, ensuring that the joint gap is no more than 1mm, and hydraulic lifting fixture to perform reverse deformation pre-bending treatment on the base plate. Step 2: Preparation for longitudinal fillet welds: Check the laser protective lens to ensure it is clean and free of contamination; check the welding shielding gas and verify the laser head position, MAG welding torch position, and filament spacing on the reference table; Step 3: Laser-MAG composite welding of longitudinal fillet welds: Double-sided symmetrical welding is performed using laser-MAG composite welding technology. The laser-MAG composite welding process involves double-sided welding torches and laser heads. The distance between the double-sided welding torches is 100~200mm. The welding parameters used are as follows: laser power is 4~6KW, defocusing amount is 0~-2mm, filament distance is 0~2mm, MAG welding current is 250~280A, welding voltage is 28~32V, and welding speed is 2.5~3.5m / min. Step c: After the longitudinal skeleton is completed, the fillet welds of the transverse T-row structure are welded using a fully automated robotic flux-cored wire gas shielded welding process. Other small support web structure components are welded using a semi-automatic flux-cored wire gas shielded welding process. Step d: After the sections are flipped over, the reverse side of the weld seam is welded using a double-wire submerged arc welding process. The two welding wires are arranged longitudinally, with the front wire tilted forward by 8~9° and the rear wire tilted backward by 15°. The spacing between the welding wires is 20-30mm. The two welding wires are kept in the same straight line with the center of the weld seam and share a single molten pool during welding. The welding parameters used are as follows: the front wire is DC, the welding current is 1000~1100A, and the welding voltage is 32~35V; the rear wire is AC, the welding current is 800~900A, the welding voltage is 38~40V, and the welding speed is 0.9~1.2m / min.

2. The laser composite welding process for ship section construction according to claim 1, characterized in that: In step a, the laser beam and welding wire are aligned with the front end of the plate seam, the laser head is perpendicular to the plate, the MAG welding gun is at a 45° angle to the plate and is in a dragging arc posture, and in step 3, the length of the positioning weld is 300-500mm, and the number of positioning welds for each plate seam is not less than 3.

3. The laser composite welding process for ship section construction according to claim 1, characterized in that: In step b, the laser head is at a 25° angle to the base plate, the MAG welding gun is at a 45° angle to the base plate and is in a dragging arc posture, the laser beam is 1-2 mm above the intersection of the base plate and the vertical plate, and the tip of the welding wire is at the intersection of the base plate and the vertical plate, at which time the extension length of the welding wire is 22 mm.

4. The laser composite welding process for ship section construction according to claim 1, characterized in that: The laser hybrid welding process in step b uses an Ar-CO2 mixed gas with an Ar to CO2 ratio of 92:8 and a flow rate of 40~50 L / min.

5. The laser composite welding process for ship section construction according to claim 1, characterized in that: The laser-arc hybrid welding equipment includes a fiber laser and a pulsed welding power source. The laser-arc hybrid method is that the MAG welding torch is in front and the laser head is behind. The laser head and the MAG welding torch move in a straight line without oscillation.

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