Vacuum laser welding method and system for spaceflight ultrahigh-strength steel

Abstract

The invention provides a vacuum laser welding method and system for spaceflight ultrahigh-strength steel, and the method comprises the following steps: a pretreatment step: pretreating the ultrahigh-strength steel, and assembling and fixing the ultrahigh-strength steel; a welding parameter setting step: setting welding parameters of a welding gun; the welding parameters comprise a welding angle, a welding speed and a welding path; a vacuum extraction step: extracting air in the vacuum cabin until the vacuum degree reaches a preset value; and a welding step: welding the ultrahigh-strength steel in the vacuum cabin based on the set welding parameters. According to the vacuum laser welding method, laser welding is carried out in the vacuum negative pressure environment, the plasma shielding effect is effectively restrained, the laser energy utilization rate and the welding penetration depth are remarkably increased, meanwhile, the defects such as air holes and cracks are avoided, and the vacuum laser welding method has the beneficial effects of being high in welding efficiency, small in heat input and excellent in weld joint mechanical property.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of welding manufacturing, in particular, to a vacuum laser welding method and system for aerospace ultra-high strength steel. BACKGROUND

[0002] Aerospace ultra-high strength steel is mainly used in solid rocket engine shell, manned spacecraft, aircraft landing gear and other occasions with large load bearing and strict lightweight requirements due to its ultra-high strength and good plasticity and toughness. Welding is one of the key processes for forming structural parts. Currently, GTAW tungsten electrode argon arc welding and electron beam welding methods are mainly used for welding of rocket engine shells. GTAW has large heat input, large internal stress and thermal deformation, low arc power density, low penetration, and shallow penetration. For wall thicknesses above 3mm, multi-layer multi-pass welding with beveling is usually required, and preheating before welding and stress relief and hydrogen removal treatment after welding are also required, which is complex and has low welding efficiency. Electron beam welding has high power density and strong penetration, but requires high vacuum degree of 10 -3 Pa or below, which has low welding efficiency and cannot meet the current rapid development requirements.

[0003] Laser welding has high power density, high welding efficiency and good welding quality, and has wide application prospects in the field of major equipment manufacturing such as aerospace. However, aerospace ultra-high strength steel has high carbon content, many alloying elements, and large hardening tendency, and the viscosity of the molten pool metal is large. In addition, laser welding has rapid cooling and heating, and has a large depth-to-width ratio, which makes it difficult for bubbles to overflow, and it is difficult to control the composition of the bottom weld metal, and the plasticity and toughness of the weld are low. Pores and cracks have always been key problems limiting its application. Currently, research has been conducted on various welding methods for aerospace ultra-high strength steel such as D406A, 30Cr3, and 30CrMnSiA, including pure laser fusion welding, laser-TIG hybrid welding, laser-CMT hybrid welding, and laser-swing welding, which have achieved certain results, improved welding quality, and improved welding efficiency.

[0004] Patent document CN105328342A discloses a method for eliminating pores in laser welding of medium-thick D406A ultra-high strength steel. For 10mm ultra-high strength steel D406A, a 30-degree bevel is used, and laser-TIG hybrid welding is used to form two layers, which may solve the problem of pores, but has low welding efficiency, high filler wire filling amount, and large heat input, which causes large thermal deformation.

[0005] Patent document CN114769881A discloses a D406A steel laser-CMT hybrid welding method. By optimizing the process parameters, high-quality welding under pure argon protection is achieved, the problems of poor weld formation and pores are solved, and the welding efficiency and internal quality are improved, but it is limited to 2.8mm thick sheet.

[0006] Patent document CN114799526A discloses a D406A steel narrow gap laser oscillation-wire filling composite welding method. By high-power laser oscillation deep penetration welding, a large blunt edge is realized, and pores are effectively eliminated. The laser oscillation and wire filling composite method is used to fill the narrow gap groove layer by layer, and the side wall unmelting problem is solved. Finally, the oscillating laser wire filling composite cap welding is used to ensure that the weld has no undercut. The overall process is relatively complex, the number of welding layers is too large in thick plate welding, the overall efficiency is relatively low, and the repeated heat input leads to a large weld heat affected zone and increased deformation.

[0007] Overall, the above method has the following disadvantages:

[0008] (1) Welding in the atmosphere, the shielding effect of plasma is serious, which seriously reduces the penetration depth of the laser and affects the welding efficiency;

[0009] (2) The stability of the spoon hole is poor, the air pressure above the workpiece is large, and hydrogen or air in the material is easy to be rolled into the molten pool to form pores;

[0010] (3) The depth-width ratio of the molten pool metal is large, the metal composition at the bottom of the weld is difficult to control, and the plasticity and toughness of the joint are low. If the laser welding is placed in a vacuum environment, the welding process and quality will be significantly different. The shielding effect of laser-induced plasma in the atmospheric environment is eliminated, so that the laser energy can be transmitted to the deep part of the molten pool without loss, the welding penetration is significantly increased, the welding efficiency is further improved, and the heat input is reduced; in a low vacuum environment, there is no disturbance of sensitive gases such as hydrogen, oxygen and nitrogen to the molten pool and keyhole, so that there is almost no pore in vacuum welding; further, in a vacuum environment, there is no plasma shielding effect, the molten pool and the spoon hole are stable, the crystallization process is uniform, and the grain is small, which helps to improve the plasticity and toughness of the joint. More importantly, the vacuum degree required for vacuum laser welding is lower than that of electron beam welding, and the environmental pressure only needs to reach 10 3 Pa or below, which is easier to construct a large vacuum chamber and has relatively lower equipment cost and higher welding efficiency than electron beam welding. Obviously, in the case where the size of the workpiece is not limited, vacuum laser welding is an ideal solution for welding aerospace ultra-high strength steel.

[0011] After searching and analyzing the existing technical documents, it is found that there is no method of vacuum laser welding for welding aerospace ultra-high strength steel. SUMMARY

[0012] In view of the defects in the prior art, the purpose of the present application is to provide a vacuum laser welding method and system for aerospace ultra-high strength steel.

[0013] According to the vacuum laser welding method for aerospace ultra-high strength steel provided by the present application, the method comprises the following steps:

[0014] The pre-treatment step is to pre-treat the ultra-high strength steel and assemble and fix it;

[0015] The welding parameter setting step is to set the welding parameters of the welding torch;

[0016] The welding parameters include a welding angle, a welding speed and a welding path;

[0017] The vacuum extraction step is to extract air in the vacuum chamber until the vacuum degree reaches a preset value;

[0018] The welding step is to weld the ultra-high strength steel in the vacuum chamber based on the set welding parameters.

[0019] Preferably, the pre-treatment step comprises:

[0020] The ultra-high strength steel is processed into an I-shaped groove or an I-shaped+U / V-shaped groove form;

[0021] The end surface to be welded of the ultra-high strength steel is polished and cleaned, and the assembly and fixation are performed by using a clamp.

[0022] Preferably, the I-shaped groove comprises a straight edge form with a groove angle of 0 degrees and a groove thickness of 3-40 mm; in the I-shaped+U / V-shaped groove, the I-shaped groove is adopted for the backing fillet, the fillet thickness is 3-40 mm, and the U / V-shaped groove is adopted for the filling or covering part; the V-shaped groove angle is 30 degrees, the U-shaped groove angle is 0-3 degrees, and the bottom groove width is 3-6 mm.

[0023] Preferably, the welding parameter setting step comprises:

[0024] The welding path programming and the welding parameter setting are performed, the defocusing amount of the welding torch is adjusted to be -20 mm-+20 mm, the welding angle of the welding torch is adjusted to be -12°-+12°, the wire feeding angle is the included angle between the wire feeding mechanism and the workpiece surface, the angle range is 20°-60°, the light wire spacing is 0-3 mm; the backing laser power is set to be 500-30000 W, and the welding speed is 0.3-6.0 m / min; the filling welding speed is 0.3-3.0 m / min, the wire feeding speed is 0-8 m / min, and the filling welding laser power is 1000-10000 W.

[0025] Preferably, the air in the vacuum chamber is extracted until a vacuum negative pressure atmosphere with a vacuum degree of 30-1000 Pa is reached.

[0026] According to the present application, a vacuum laser welding system for aerospace ultra-high strength steel is provided, comprising:

[0027] A pre-treatment module is configured to pre-treat the ultra-high strength steel and assemble and fix it;

[0028] A welding parameter setting module is configured to set the welding parameters of the welding torch;

[0029] The welding parameters include a welding angle, a welding speed and a welding path;

[0030] The vacuum extraction module extracts air in the vacuum chamber until the vacuum degree reaches a preset value;

[0031] The welding module welds the ultra-high strength steel in the vacuum chamber based on the set welding parameters.

[0032] Preferably, the pre-processing module comprises:

[0033] The ultra-high strength steel is processed into an I-shaped groove or an I-shaped+U / V-shaped groove form;

[0034] The end surface to be welded of the ultra-high strength steel is polished and cleaned, and assembled and fixed by using a clamp.

[0035] Preferably, the I-shaped groove comprises a straight edge form with a groove angle of 0 degrees and a groove thickness of 3-40 mm; in the I-shaped+U / V-shaped groove, the I-shaped groove is used for the backing fillet, the fillet thickness is 3-40 mm, and the U / V-shaped groove is used for the filling or covering part; the V-shaped groove angle is 30 degrees, the U-shaped groove angle is 0-3 degrees, and the bottom groove width is 3-6 mm.

[0036] Preferably, the welding parameter setting module comprises:

[0037] The welding path is programmed and the welding parameters are set, the defocusing amount of the welding gun is adjusted to -20 mm-+20 mm, the welding angle of the welding gun is -12°-+12°, the wire feeding angle is the included angle between the wire feeding mechanism and the workpiece surface, the angle range is 20°-60°, the light wire spacing is 0-3 mm; the backing laser power is set to 500-30000 W, the welding speed is 0.3-6.0 m / min; the filling welding speed is 0.3-3.0 m / min, the wire feeding speed is 0-8 m / min, and the filling welding laser power is 1000-10000 W.

[0038] Preferably, the air in the vacuum chamber is extracted until a vacuum negative pressure atmosphere with a vacuum degree of 30-1000 Pa is reached.

[0039] Compared with the prior art, the present application has the following beneficial effects:

[0040] 1. The vacuum laser welding method effectively suppresses the plasma shielding effect by performing laser welding in a vacuum negative pressure environment, significantly improves the laser energy utilization rate and welding penetration, and avoids the generation of defects such as pores and cracks, and has the characteristics of high welding efficiency, small heat input and excellent weld mechanical properties.

[0041] 2. This invention proposes to use laser welding in a vacuum environment, which effectively suppresses the plasma generated during the laser welding process, significantly improves energy utilization, and significantly improves the weld penetration and depth-to-width ratio. Under the same parameter conditions, the penetration of vacuum welding is about 3 times that of atmospheric welding, which is conducive to high-quality and efficient welding of ultra-high strength steel thick-walled structures.

[0042] 3. The welding process of this invention is completed in a vacuum. The vacuum environment completely eliminates interference from gases such as oxygen and nitrogen, significantly reducing impurity gas elements in the weld zone and preventing the formation of oxides, nitrides, and other impurities. Simultaneously, the absence of plasma shielding in a vacuum environment ensures a stable molten pool and keyhole, uniform crystallization, and fine grains, contributing to improved joint ductility and toughness. This significantly improves the weld microstructure and mechanical properties. The tensile strength of the weld without post-weld heat treatment can reach up to 110% (810 MPa) of the base metal, and the elongation can reach 16%, significantly exceeding the elongation of laser-CMT welding and pure laser fusion welding by more than twice, thus enhancing the joint's ductility and toughness.

[0043] 4. The vacuum environment during welding alters the physical properties of the molten pool. In a low-pressure environment, the melting and boiling points of the metal decrease, allowing for greater penetration depth at the same laser energy density. Furthermore, the molten pool temperature is lower, making it less prone to cracking defects and resulting in a smaller heat-affected zone. In a low-vacuum environment, the absence of sensitive gases such as hydrogen, oxygen, and nitrogen disturbs the molten pool and keyholes, resulting in virtually no porosity during vacuum welding. This effectively avoids porosity defects that are difficult to eliminate in deep penetration welding of ultra-high-strength steel, making it an ideal solution for welding thick plates of aerospace ultra-high-strength steel with high carbon equivalent.

[0044] 5. Vacuum laser welding has a lower vacuum requirement compared to electron beam welding; the ambient pressure only needs to reach 10. 3 Below Pa, it is easier to construct large vacuum chambers, resulting in relatively lower equipment costs and higher welding efficiency compared to electron beam welding. Clearly, when workpiece size is not a constraint, vacuum laser welding is a more ideal solution for welding aerospace ultra-high-strength steel. Attached Figure Description

[0045] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0046] Figure 1 This is a schematic diagram of vacuum laser welding according to the present invention.

[0047] Figure 2 This is a schematic diagram of the I-type + V-type bevel of the aerospace ultra-high strength steel thick plate of the present invention.

[0048] Figure 3 This is a cross-sectional view of the weld seam in Embodiment 1 of the present invention.

[0049] Figure 4 X-ray flaw detection results of Example 1 of the present application.

[0050] Figure 5 Comparison chart of weld mechanical properties of Example 1 of the present application.

[0051] Figure 6 Flow chart of the method of the present application.

[0052] Explanation of reference signs

[0053] Large vacuum chamber 1

[0054] Observation window 2

[0055] Laser beam 3

[0056] Metal shield 4

[0057] Welding wire 5 DETAILED DESCRIPTION

[0058] The present application will be described in detail below with specific embodiments. The following examples will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present application. These are within the scope of protection of the present application.

[0059] Referring to Figure 1 and Figure 6 , a high-quality and efficient vacuum laser welding method for aerospace ultra-high strength steel is shown, which specifically includes:

[0060] Step S1: bevel machining

[0061] The ultra-high strength steel is machined into an I-shaped bevel or an I-shaped + U / V-shaped bevel form;

[0062] Step S2: pre-welding preparation

[0063] Step S201: clean and assemble the workpiece

[0064] The end surface of the ultra-high strength steel to be welded and the oxide film and stains near the welding position are polished with an oil-free dry clean steel wire brush, and the residual oil stains in the polished area are wiped with anhydrous ethanol; and the workpiece is assembled and fixed with a clamp;

[0065] Step S202: program the welding path and set the parameters

[0066] Adjust the defocus amount of the welding torch, the welding angle of the welding torch and the wire feeding mechanism, and the light wire spacing; program the welding path; set the key welding parameters such as the laser power of the laser beam 3, the start and stop arc process parameters, the welding speed, and the wire feeding speed;

[0067] Step S3: vacuumizing

[0068] Close the hatch and vacuumize the large vacuum chamber 1 to the required vacuum degree for the welding process;

[0069] Step S4: welding

[0070] Weld the welding piece by the welding wire 5 with the set welding parameters, the welding process can be observed through the observation window 2, and the safety is ensured by the metal protective cover 4.

[0071] The I-shaped groove is a straight edge with a groove angle of 0 degrees; the groove thickness is 3-40 mm; the I-shaped + U-shaped / V-shaped groove, wherein the I-shaped groove is used for the bottom edge, the edge thickness is 3-40 mm, the U-shaped / V-shaped groove is used for the filling or surface covering part, the V-shaped groove angle is 30 degrees, the U-shaped groove angle is 0-3 degrees, and the bottom groove width is 3-6 mm.

[0072] The cleaning and assembly of the workpiece before welding adopts mechanical polishing and chemical cleaning of the groove and the surrounding welding area to remove the surface oxide film and oil stains, and the workpiece is assembled and fixed by the clamp after drying.

[0073] The welding path programming and parameter setting step before welding adopts: adjusting the defocusing amount of the welding gun to -20mm-+20mm, the welding angle of the welding gun to -12°-+12°, the wire feeding angle to 20°-60°, the distance between the light and the wire to 0-3mm; setting the bottom laser power to 500-30000W, the welding speed to 0.3-6.0m / min; the filling welding speed to 0.3-3.0m / min, the wire feeding speed to 0-8m / min, and the filling welding laser power to 1000-10000W.

[0074] The vacuumizing step adopts: vacuumizing the vacuum chamber to a vacuum negative pressure atmosphere required for the welding process, which is 30-1000Pa;

[0075] The above is the basic embodiment of the present application, and the content of the present application will be further illustrated by two preferred embodiments.

[0076] Example 1

[0077] As shown in Figure 1 and Figure 2 A vacuum laser welding method of ultra-high strength steel, comprising:

[0078] Step S1: groove processing

[0079] The ultra-high strength steel is processed into an I-shaped groove;

[0080] Step S2: Pre-welding preparation

[0081] Step S201: Clean and assemble the workpiece

[0082] Use a clean, dry, oil-free steel wire brush to polish the end face of the ultra-high strength steel to be welded, as well as the oxide film and stains near the welding position. Then wipe the residual oil stains in the polished area with anhydrous ethanol. Finally, assemble and fix the steel with clamps.

[0083] Step S202: Programming the welding path and setting parameters

[0084] Adjust the defocusing amount of the welding torch, the welding angle between the welding torch and the wire feeding mechanism, and the wire spacing; program the welding path; set key welding parameters such as laser power, arc start and end process parameters, welding speed, and wire feeding speed;

[0085] Step S3: Vacuuming

[0086] Close the hatch and evacuate the large vacuum chamber 1 to the vacuum level required for the welding process;

[0087] Step S4: Welding

[0088] Welding is performed on the workpiece using the set welding parameters.

[0089] The type I bevel is a straight edge with a bevel angle of 0 degrees; the bevel thickness is 20mm.

[0090] The pre-welding preparation steps for cleaning and assembling the workpiece are as follows: mechanically grind and chemically clean the bevel and surrounding welding area to remove the oxide film and oil stains on the surface, and then assemble and fix it with a fixture after drying.

[0091] The steps for adjusting the welding posture and setting parameters before welding are as follows: adjust the welding torch defocusing amount by -5 to -10mm, the welding torch welding angle by +12°, the laser power by 6000W, and the welding speed by 0.3 to 0.6m / min.

[0092] The vacuuming step involves evacuating the vacuum chamber to a vacuum negative pressure atmosphere of 30-100 Pa required for the welding process.

[0093] In this embodiment, the welding of 20mm thick ultra-high strength steel can be completed in a single pass under vacuum negative pressure environment.

[0094] like Figure 3 As shown, the weld cross-section exhibits a uniform penetration morphology with a high aspect ratio, free from defects such as incomplete fusion and cracks, and has a narrow heat-affected zone. This indicates that the vacuum environment effectively suppressed plasma interference, improved laser energy concentration, and enabled efficient single-pass welding of thick plates.

[0095] Figure 4 The X-ray flaw detection result in the table shows that there is no pore or inclusion in the weld, which proves that the vacuum environment (30-100 Pa) reduces the solubility of gas in the molten pool, avoids the involvement of impurity gases such as hydrogen and oxygen, and solves the problem of frequent occurrence of pores in traditional laser welding.

[0096] Figure 5 The mechanical property test shows that the tensile strength of the weld reaches 810 MPa (110% of the base material), and the elongation reaches 16%, which is much higher than the performance of laser-CMT welding and pure laser fusion welding in the atmospheric environment (the elongation is usually less than 10%). The vacuum environment optimizes the solidification process of the molten pool, reduces the generation of brittle phases, and significantly improves the plasticity and toughness of the joint.

[0097] Embodiment 2

[0098] As shown in Figure 1 and Figure 2 , a vacuum laser welding method of ultra-high strength steel comprises the following steps:

[0099] Step S1: groove processing

[0100] The ultra-high strength steel is processed into an I-shaped groove or an I-shaped + U / V-shaped groove form;

[0101] Step S2: preparation before welding

[0102] Step S201: clean and assemble the workpiece

[0103] Use an oil-free dry clean steel wire brush to polish the end surface of the ultra-high strength steel to be welded, and the oxide film and stains near the welding position, and then use anhydrous ethanol to wipe the residual oil stains in the polished area; and use a clamp to assemble and fix;

[0104] Step S202: program the welding path and set the parameters

[0105] Adjust the defocusing amount of the welding gun, the welding angle of the welding gun and the wire feeding mechanism, and the distance between the light and the wire; program the welding path; set the key welding parameters such as laser power, arc striking process parameters, welding speed, and wire feeding speed;

[0106] Step S3: vacuumizing

[0107] Close the hatch and vacuumize the large vacuum chamber 1 to the required vacuum degree for the welding process;

[0108] Step S4: welding

[0109] Use the set welding parameters to weld the welding piece.

[0110] The groove is an I+V type groove, wherein the root face is in the form of a straight edge with a groove angle of 0 degrees; the thickness is 20 mm, the V type groove is a cover surface groove, the angle is 30 degrees, and the filling depth is 2-6 mm;

[0111] The cleaning and assembling of the workpiece before welding adopts mechanical polishing and chemical cleaning on the groove and the surrounding welding area to remove the surface oxide film and oil stains, and the workpiece is assembled and fixed by using a clamp after being blown dry.

[0112] The adjustment of the welding position and the setting of the parameters before welding adopts the following steps: adjusting the defocusing amount of the welding gun to be-5--10 mm, the welding angle of the welding gun to be+12°, the distance between the light wires to be 0-3 mm, the angle between the wire feeding angle and the workpiece to be 30 degrees, the laser power to be 7000 W, the welding speed to be 0.3-0.6 m / min, and the wire feeding speed to be 0.3-1.2 m / min.

[0113] The vacuum extraction step adopts the following steps: the vacuum chamber is extracted to a vacuum negative pressure atmosphere required by the welding process, and the vacuum degree is 30-100 Pa.

[0114] The application also provides a vacuum laser welding system for aerospace ultra-high strength steel, which can be realized by executing the process steps of the vacuum laser welding method for aerospace ultra-high strength steel, that is, the vacuum laser welding method for aerospace ultra-high strength steel can be understood by those skilled in the art as a preferred embodiment of the vacuum laser welding system for aerospace ultra-high strength steel.

[0115] Specifically, a vacuum laser welding system for aerospace ultra-high strength steel comprises:

[0116] A pretreatment module: the ultra-high strength steel is pretreated and assembled and fixed;

[0117] A welding parameter setting module: the welding parameters of the welding gun are set;

[0118] The welding parameters include the welding angle, the welding speed and the welding path;

[0119] A vacuum extraction module: the air in the vacuum chamber is extracted until the vacuum degree reaches a preset value;

[0120] A welding module: the ultra-high strength steel is welded in the vacuum chamber based on the set welding parameters.

[0121] The pretreatment module comprises:

[0122] The ultra-high strength steel is processed into an I type groove or an I+U / V type groove;

[0123] The end surface to be welded of the ultra-high strength steel is polished and cleaned, and the workpiece is assembled and fixed by using a clamp.

[0124] The I type groove includes a straight edge form with a groove angle of 0 degrees, and a groove thickness of 3mm-40mm; in the I+U / V type groove, the I type groove is used for the bottom bevel, the bevel thickness is 3mm-40mm, and the U / V type groove is used for the filling or facing part; the V type groove angle is 30 degrees, the U type groove angle is 0-3 degrees, and the bottom groove width is 3mm-6mm.

[0125] The welding parameter setting module comprises:

[0126] The welding path programming and welding parameter setting are performed, the defocusing amount of the welding gun is adjusted to be-20mm-+20mm, the welding angle of the welding gun is-12°-+12°, the wire feeding angle is the included angle between the wire feeding mechanism and the workpiece surface, the angle range is 20°-60°, the light wire spacing is 0-3mm; the bottom laser power is set to be 500-30000W, and the welding speed is 0.3-6.0m / min; the filling welding speed is 0.3-3.0m / min, the wire feeding speed is 0-8m / min, and the filling welding laser power is 1000-10000W.

[0127] The air in the vacuum chamber is extracted until a vacuum negative pressure atmosphere with a vacuum degree of 30-1000Pa is reached.

[0128] Those skilled in the art know that, in addition to implementing the system provided by the present application and each device, module and unit thereof in a pure computer readable program code manner, the system provided by the present application and each device, module and unit thereof can also be implemented in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps to achieve the same functions. Therefore, the system provided by the present application and each device, module and unit thereof can be considered as a hardware component, and the devices, modules and units included therein for achieving various functions can also be considered as structures in the hardware component; the devices, modules and units for achieving various functions can also be considered as both software modules for implementing methods and structures in the hardware component.

[0129] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essential content of the present application. The embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other without conflict.

Claims

1. A vacuum laser welding method of aerospace ultra-high strength steel, characterized by, The method comprises the following steps: A pretreatment step: pretreat the ultra-high strength steel and assemble and fix it; A welding parameter setting step: set the welding parameters of the welding torch; The welding parameters include welding angle, welding speed and welding path; A vacuum extraction step: extract the air in the vacuum chamber until the vacuum degree reaches a preset value; A welding step: weld the ultra-high strength steel in the vacuum chamber based on the set welding parameters.

2. The vacuum laser welding method of aerospace ultra-high strength steel according to claim 1, characterized in that, The pretreatment step comprises: Process the ultra-high strength steel into an I-shaped groove or an I-shaped+U / V-shaped groove; Grind and clean the end surface to be welded of the ultra-high strength steel and assemble and fix it using a clamp.

3. The vacuum laser welding method of aerospace ultra-high strength steel according to claim 2, characterized in that, The I-shaped groove includes a straight edge form with a groove angle of 0 degrees and a groove thickness of 3-40 mm; in the I-shaped+U / V-shaped groove, the I-shaped groove is used for the bottom fillet, the fillet thickness is 3-40 mm, and the U / V-shaped groove is used for the filling or surface covering part; the V-shaped groove angle is 30 degrees, the U-shaped groove angle is 0-3 degrees, and the bottom groove width is 3-6 mm.

4. The vacuum laser welding method of aerospace ultra-high strength steel according to claim 1, characterized in that, The welding parameter setting step comprises: Program the welding path and set the welding parameters, adjust the defocusing amount of the welding torch to -20 mm-+20 mm, the welding angle of the welding torch to -12°-+12°, the wire feeding angle to the included angle between the wire feeding mechanism and the workpiece surface, the angle range to 20°-60°, the light wire spacing to 0-3 mm; set the bottom laser power to 500-30000 W, the welding speed to 0.3-6.0 m / min; the filling welding speed to 0.3-3.0 m / min, the wire feeding speed to 0-8 m / min, and the filling welding laser power to 1000-10000 W.

5. The method of vacuum laser welding of aerospace ultra-high strength steel according to claim 1, wherein, Extract the air in the vacuum chamber until a vacuum negative pressure atmosphere with a vacuum degree of 30-1000 Pa is reached.

6. A vacuum laser welding system of aerospace ultra-high strength steel, characterized in that, The method comprises the following steps: A pretreatment module: pretreat the ultra-high strength steel and assemble and fix it; A welding parameter setting module: set the welding parameters of the welding torch; The welding parameters include welding angle, welding speed and welding path; A vacuum extraction module: extract the air in the vacuum chamber until the vacuum degree reaches a preset value; A welding module: weld the ultra-high strength steel in the vacuum chamber based on the set welding parameters.

7. The system for vacuum laser welding of aerospace ultra-high strength steel according to claim 6, wherein, The pretreatment module comprises: Process the ultra-high strength steel into an I-shaped groove or an I-shaped+U / V-shaped groove; Grind and clean the end surface to be welded of the ultra-high strength steel and assemble and fix it using a clamp.

8. The system for vacuum laser welding of aerospace ultra-high strength steel according to claim 7, wherein, The I-shaped groove includes a straight edge form with a groove angle of 0 degrees and a groove thickness of 3-40 mm; in the I-shaped+U / V-shaped groove, the I-shaped groove is used for the bottom fillet, the fillet thickness is 3-40 mm, and the U / V-shaped groove is used for the filling or surface covering part; the V-shaped groove angle is 30 degrees, the U-shaped groove angle is 0-3 degrees, and the bottom groove width is 3-6 mm.

9. The system for vacuum laser welding of aerospace ultra-high strength steel of claim 6, wherein, The welding parameter setting module comprises: The welding path is programmed and the welding parameters are set, the defocusing amount of the welding torch is adjusted to be -20mm-+20mm, the welding angle of the welding torch is -12°-+12°, the wire feeding angle is the included angle between the wire feeding mechanism and the workpiece surface, the angle range is 20°-60°, the light wire spacing is 0-3mm; the backing laser power is set to be 500-30000W, the welding speed is 0.3-6.0m / min; the filling welding speed is 0.3-3.0m / min, the wire feeding speed is 0-8m / min, and the filling welding laser power is 1000-10000W.

10. The vacuum laser welding system of aerospace ultra-high strength steel according to claim 6, characterized in that, The air in the vacuum chamber is extracted until a vacuum negative pressure atmosphere with a vacuum degree of 30-1000 Pa is reached.

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