Dual-energy different-beam laser arc composite efficient welding method for large thick-wall component

Abstract

The invention provides a double-energy different-beam laser arc composite efficient welding method for a large thick-wall component, a composite heat source comprises a common single laser beam, a scanning laser beam and a welding arc which are sequentially arranged, and the welding method comprises the following steps that before welding, a groove with a certain angle and a penetrating gap is formed in the large thick-wall component; the groove of the large thick-wall component is sequentially divided into a truncated edge penetrating area, a middle expansion area and a remaining coverage area outside the truncated edge penetrating area from bottom to top in the thickness direction; during welding, one-time welding double-face forming of the large thick-wall component is achieved through the synergistic effect of the three heat sources; wherein the common single laser beam is used for completely penetrating through the truncated edge penetrating area so as to carry out penetrating welding on a gap at the truncated edge; the scanning laser beam is used for welding the side wall of the middle expansion area so as to effectively fuse the middle side wall; the welding arc is used for full-coverage welding and effective filling of the remaining coverage area. The technical problem of single-pass welding bottleneck of the large thick-wall component with the thickness being 20 mm or above is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of composite welding, and in particular to a high-efficiency dual-energy different-beam laser arc composite welding method for thick-walled components. Background Art

[0002] Laser arc hybrid welding (LAHW) combines the advantages of laser and arc welding. It combines the high penetration of a laser beam with the large fill capacity of arc welding. The combined heat sources of these two technologies also result in improved heat source stability and higher welding efficiency. This technology significantly increases the weldable thickness in a single pass and effectively utilizes the filler metal in the arc weld. Therefore, it is particularly well-suited for welding thick-walled components (e.g., over 15 mm thick) in terms of welding efficiency, forming quality, and joint performance. Data indicates that the maximum weldable thickness limit for a single pass of LHW is approximately 20 mm. However, with the increasing demand for welding thick-walled components (over 20 mm thick) in the manufacturing of large ships, nuclear power plants, oil pipelines, and boilers in recent years, the bottleneck of LHW's weldable thickness in a single pass needs to be overcome to further improve welding efficiency.

[0003] However, as component thickness increases, laser hybrid welding faces numerous technical challenges, even with groove butt welding. For example, increasing the groove depth can address laser penetration issues, but to ensure a full weld, the arc power typically needs to be increased to increase the amount of wire deposited. This often leads to overheating of the molten pool metal, seriously affecting weld formation, joint performance, and microstructure. On the other hand, reducing the groove angle to reduce filler metal requirements can lead to sidewall incomplete fusion defects due to the difficulty of the laser and arc heat sources fully covering the groove. If the groove remains unchanged and the blunt edge thickness is increased, single-pass welding requires higher laser line energy to achieve greater penetration. However, this means more intense thermal reactions within the keyhole, increased thermal gradients in the molten pool, and increased amounts of interfering substances such as plume, smoke, and spatter. This can lead to a series of welding and manufacturing issues, including increased porosity, decreased forming stability, reduced penetration conversion efficiency, increased weld deformation, and weakened joint performance. Therefore, the technical bottlenecks of single-pass welding of thick-walled components over 20 mm in thickness urgently need to be addressed. Summary of the Invention

[0004] The purpose of the present invention is to provide a dual-energy different-beam laser arc composite high-efficiency welding method for large thick-walled components, which solves the technical problem of the bottleneck of single-pass welding of large thick-walled components with a thickness of more than 20 mm.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows: The present invention provides a dual-energy, different-beam laser arc composite high-efficiency welding method for thick-walled components. The dual-energy, different-beam laser arc composite heat source includes a common single laser beam, a scanning laser beam, and a welding arc arranged in sequence. The welding method includes the following steps: before welding, a groove with a certain angle and a penetration gap is first opened on the thick-walled component; the groove of the thick-walled component is divided into a blunt edge penetration area, a middle expansion area, and a remaining coverage area from bottom to top along the thickness direction; during welding, one-time welding and double-sided forming of the thick-walled component is achieved through the synergistic action of three heat sources; wherein, the common single laser beam is used to completely penetrate the blunt edge penetration area to perform penetration welding on the gap at the blunt edge; the scanning laser beam is used to weld the side wall of the middle expansion area to effectively fuse the middle side wall; and the welding arc is used to perform full coverage welding and effective filling on the remaining coverage area.

[0006] Furthermore, the welding arc, the scanning laser beam and the ordinary single laser beam are arranged in sequence along the welding direction.

[0007] Furthermore, the groove adopts a "Y"-shaped groove or a "U"-shaped groove with a penetration gap.

[0008] Furthermore, the gap width at the blunt edge of the groove is less than 1 mm.

[0009] Furthermore, the thickness of the blunt edge penetration area ranges from 10 to 20 mm.

[0010] Furthermore, the thickness of the middle expansion area ranges from 2 to 15 mm.

[0011] Furthermore, the thickness of the remaining coverage area ranges from 3 to 10 mm.

[0012] Furthermore, the welding arc adopts metal electrode gas shielded welding or tungsten electrode gas shielded welding.

[0013] Compared with the prior art, the present invention has at least the following beneficial effects: 1. The present invention uses three heat sources to weld three sections in the thickness direction of thick-walled components respectively. This effectively breaks through the weldable thickness limit of laser arc hybrid welding without increasing the energy of a single laser beam line, and to a certain extent reduces the dependence on ultra-high power lasers when welding thick-walled components.

[0014] 2. The present invention supports the use of a small-angle groove. Although the groove depth is increased, the metal filling amount can be better controlled, so there is no need to increase the amount of welding wire deposition by increasing the arc power, effectively avoiding problems such as weld formation, joint performance and organizational structure deterioration, and increased deformation caused by overheating of the molten pool metal.

[0015] 3. The present invention does not rely on simply increasing the energy of a single laser line to achieve greater penetration, will not intensify the thermal reaction in the keyhole, and can effectively suppress the increase in the thermal field gradient of the molten pool and the large-scale production of interfering substances such as plume, smoke, and spatter. Therefore, it can easily solve a series of welding manufacturing problems caused by high-power laser welding, such as increased porosity tendency, decreased forming stability, reduced penetration conversion efficiency, increased welding deformation, and weakened joint performance.

[0016] 4. The scanning laser welding used in the present invention can effectively solve the problem of side wall unfusion defects caused by the difficulty of using conventional laser arc composite heat source to completely cover the groove area during small-angle groove welding.

[0017] 5. This invention supports the use of a shallow "Y"-shaped groove or a small-gap "U"-shaped groove with a certain angle. During welding, the cross-section of the molten pool presents a uniform transition from wide at the top to narrow at the bottom, which helps to float process-related pores during welding and reduce pore defects. Furthermore, the narrow-gap groove helps reduce weld line energy input, reducing welding stress and deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 Schematic diagram of the structure when welding using the welding method of the present invention; wherein the direction of the arrow indicates the welding direction; Figure 2 It is a right side view schematic diagram of welding using the welding method of the present invention.

[0020] mark: 1-Ordinary single laser beam; 2-Scanning laser beam; 3-Welding arc; 4-Blunt edge penetration area; 5-Middle expansion area; 6-Remaining coverage area. DETAILED DESCRIPTION

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0022] This embodiment provides a high-efficiency dual-energy laser arc hybrid welding method for thick-walled components. Figure 1-2 As shown, the dual-energy different-beam laser arc composite heat source includes a welding arc 3, a scanning laser beam 2, and an ordinary single laser beam 1 arranged in sequence along the welding direction; the welding method includes the following steps: Before welding, a Y-shaped or U-shaped groove with a certain angle and a penetration gap is formed on the thick-walled component, where the cross-sectional area of the groove is smaller than the maximum fill volume of the arc welding. The groove of the thick-walled component is divided from bottom to top along the thickness direction into a blunt edge penetration area 4, a middle expansion area 5, and a remaining coverage area 6. During welding, the coordinated action of three heat sources is used to achieve double-sided forming of large thick-walled components through one-time welding; wherein, the ordinary single laser beam 1 is used to completely penetrate the blunt edge penetration area 4 to perform penetrating welding on the gap at the blunt edge; the scanning laser beam 2 is used to weld the side walls of the middle expansion area 5 to effectively fuse the middle side walls; the welding arc 3 is used to perform full coverage welding and effective filling of the remaining coverage area 6.

[0023] The gap width at the blunt edge of the groove is less than 1mm; the thickness of the blunt-edge penetration area 4 ranges from 10-20mm; the thickness of the intermediate extension area 5 ranges from 2-15mm; and the thickness of the remaining coverage area 6 ranges from 3-10mm. Furthermore, the gap width at the upper end of the groove is generally less than 10mm. The single-side angle of a "U"-shaped groove is 0-5°, and that of a small V (upper Y) groove is 4-15°. The single-side angle is the angle between the groove surface and the vertical line. The thickness range of each area can be determined based on the laser spot diameter, the scanning laser's swing radius, and the arc's spread coverage.

[0024] In addition, it should be noted that the present invention limits the specific application scenarios of this method, that is, its application in scenarios of small angles, high depths (V parts) and narrow gap grooves of large thick-walled components (above 25 mm).

[0025] Specific example description: 1. Three-heat source zone welding process based on "Y" type groove 1. Arrangement order of composite heat sources Composite heat source: It is composed of 1 ordinary single laser beam, 1 scanning laser beam and 1 welding arc; Along the welding direction, they are: welding arc 3, scanning laser beam 2 and ordinary single laser beam 1.

[0026] 2. Slope opening and area division A small-angle "Y"-shaped groove is opened on a 20mm thick thick-walled component, leaving a 0.6mm gap at the blunt edge, and ensuring that the corresponding groove cross-sectional area is smaller than the maximum fillable amount / area of the arc.

[0027] Along the groove thickness direction from bottom to top, it is divided into: Blunt edge penetration area (thickness 15mm), the penetration gap at the bottom of the groove; The middle expansion area (thickness 2mm) is located in the fusion area in the middle of the groove; The remaining covering area (3mm thickness) is located in the area to be filled above the groove.

[0028] 3. Three heat source collaborative welding Ordinary single laser beam: Focused on blunt edge penetration area 4, penetrating 15mm blunt edge to form penetrating welding; Scanning laser beam: Scans the middle expansion area 5 laterally to effectively fuse the middle sidewalls; Welding arc: Gas tungsten arc welding (GTAW) process is used to fill and cover the remaining area6.

[0029] 2. Welding process based on “U” groove with gap 1. Arrangement order of composite heat sources Composite heat source: It is composed of 1 ordinary single laser beam, 1 scanning laser beam and 1 welding arc; Along the welding direction, they are: welding arc 3, scanning laser beam 2 and ordinary single laser beam 1.

[0030] 2. Slope opening and area division Processing a narrow-gap, small-angle "U"-shaped groove on a 24mm thick component, with a blunt edge gap of 0.8mm, corresponds to a groove cross-sectional area that is smaller than the maximum fillable volume / area of the arc; Along the groove thickness direction from bottom to top, it is divided into: Blunt edge penetration area (thickness 10mm), the penetration gap at the bottom of the groove; The middle expansion area (8mm thickness) is located in the fusion area in the middle of the groove; The remaining covering area (thickness 6mm) is located in the area to be filled above the groove.

[0031] 3. Three heat source collaborative welding Ordinary single laser beam: Focused on blunt edge penetration area 4, penetrating 10mm blunt edge to form penetrating welding; Scanning laser beam: Scans the middle expansion area 5 laterally to effectively fuse the middle sidewalls; Welding arc: Use gas metal arc welding (GMAW) process to fill and cover the remaining area6.

[0032] The above method uses three heat sources, namely, ordinary single laser beam, scanning laser beam and welding arc, to weld three sections in the thickness direction of thick-walled components. Combined with the design of small-angle "Y"-shaped or narrow-gap "U"-shaped groove, without increasing the linear energy of a single laser beam, it not only breaks through the weldable thickness limit of laser arc hybrid welding and reduces the dependence on ultra-high power lasers, but also avoids overheating of the molten pool by controlling the metal filling amount. At the same time, scanning laser welding is used to solve the problem of unfused side walls of small-angle grooves. The groove form makes the cross-section of the molten pool conducive to the floating of process-related pores, reducing linear energy input to reduce welding stress and deformation, and effectively solving a series of problems such as pores and poor forming stability in high-power laser welding.

[0033] At the same time, the welding arc, scanning laser beam and ordinary single laser beam are arranged in sequence along the welding direction, and efficient welding of the full thickness of thick-walled components is achieved through a synchronous and coordinated spatial partitioning heat input mode: among them, the front end adopts a high-energy-density ordinary single laser beam to first penetrate the blunt edge area to form a through molten pool, laying the foundation for subsequent processing; the central scanning laser beam synchronously scans the middle of the groove horizontally, and uses the beam swing to melt the metal on both sides to eliminate the side wall unfusion defects of the small-angle groove; the rear-end welding arc is adjacent to the welded area and synchronously fills the remaining groove, and its thermal field is superimposed on the previous laser, which not only completes the metal filling through the large deposition capacity, but also stabilizes the molten pool and avoids overheating fluctuations and a series of problems caused by it.

Claims

1. A high-efficiency dual-energy laser arc hybrid welding method for thick-walled components, characterized in that: The dual-energy different-beam laser arc composite heat source includes a common single laser beam, a scanning laser beam and a welding arc arranged in sequence, and the welding method includes the following steps: Before welding, a groove with a certain angle and penetration gap is opened on the thick-walled component; Dividing the groove of the thick-walled component into a blunt edge penetration area, a middle expansion area and a remaining covering area from bottom to top along the thickness direction; During welding, the synergistic effect of three heat sources is used to achieve double-sided forming of thick-walled components in one welding. Among them, the ordinary single laser beam is used to completely penetrate the blunt edge penetration area to perform penetration welding on the gap at the blunt edge; the scanning laser beam is used to weld the side walls of the middle expansion area to effectively fuse the middle side walls; the welding arc is used to fully cover the remaining coverage area and effectively fill it.

2. The high-efficiency dual-energy different-beam laser arc hybrid welding method for thick-walled components according to claim 1 is characterized in that: The welding arc, the scanning laser beam and the ordinary single laser beam are arranged in sequence along a welding direction.

3. The high-efficiency dual-energy different-beam laser arc hybrid welding method for thick-walled components according to claim 1 is characterized in that: The groove adopts a "Y"-shaped groove or a "U"-shaped groove with a penetration gap.

4. The high-efficiency dual-energy different-beam laser arc hybrid welding method for thick-walled components according to claim 1 is characterized in that: The gap width at the blunt edge of the groove is less than 1 mm.

5. The high-efficiency dual-energy different-beam laser arc hybrid welding method for thick-walled components according to claim 1 is characterized in that: The thickness of the blunt edge penetration area ranges from 10 to 20 mm.

6. The high-efficiency dual-energy different-beam laser arc hybrid welding method for thick-walled components according to claim 1 is characterized in that: The thickness of the middle expansion area ranges from 2 to 15 mm.

7. The high-efficiency dual-energy different-beam laser arc hybrid welding method for thick-walled components according to claim 1 is characterized in that: The thickness of the remaining covered area is in the range of 3-10 mm.

8. The high-efficiency dual-energy different-beam laser arc hybrid welding method for thick-walled components according to claim 1 is characterized in that: The welding arc adopts metal electrode gas shielded welding or tungsten electrode gas shielded welding.

Images