Nickel-based alloy plate and welding method thereof
Through the fully transmissive laser welding method and parameter adjustment, the problem of nickel-based alloy weld formation defects is solved, and the efficient welding of GH3535 alloy plate is achieved, which is suitable for mass production of fourth-generation nuclear reactors.
Patent Information
- Application Number
- CN202510835483.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-20
- Publication Date
- 2025-07-22
AI Technical Summary
During the welding process of nickel-based alloys, especially GH3535 alloy, there are defects such as forming on the front collapse of the weld and the back welding tumor. Traditional welding methods are difficult to effectively control, resulting in poor welding quality and cannot meet the mass production needs of the fourth-generation nuclear reactor.
Pre-welding is performed by using fully transmissive laser welding method. By judging the type of surface defects of the weld, and adjusting the laser welding parameters, such as laser power, welding speed and spot diameter, to ensure the stability and forming quality of the weld.
The weld of nickel-based alloy plates is fully permeable, eliminates welding forming defects, obtains excellent forming quality and good mechanical properties, and is suitable for welding of medium-thickness GH3535 alloys, improving production efficiency and welding quality.
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Figure CN120347381A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a nickel-based alloy plate and a welding method thereof. Background Art
[0002] As one of the three major power supply pillars in the world, nuclear energy is characterized by low resource consumption, low environmental impact and strong supply capacity. It is a clean and efficient energy form and is the preferred energy solution for coping with the increasingly tight international energy supply trend in the future and fulfilling the national energy development needs. At present, the safety issue of nuclear energy is the core problem restricting its further development and application. Developing and researching the fourth-generation thorium-based molten salt nuclear reactor with the highest safety and economy, and realizing the demonstration application and large-scale commercial development of the fourth-generation nuclear energy system are the strategic key points that need to be overcome for the future development of advanced nuclear fission energy and the industrialization of core technologies.
[0003] Nickel-based alloys, especially GH3535 alloy, as a high-strength corrosion-resistant alloy of the Ni-Cr-Mo system with extremely excellent high-temperature corrosion resistance, have the potential to become high-temperature corrosion-resistant materials for core structures such as pressure vessels in the fourth-generation thorium-based nuclear reactor. Welding technology is a key assembly technology for large pressure vessels. Ensuring the welding quality of GH3535 alloy welds is of utmost importance for the safe and efficient production of thorium-based reactors. The arc welding technology commonly used in traditional nuclear industry has a low welding energy density and cannot penetrate thick GH3535 plates in one pass. It needs to adopt a multi-layer and multi-pass welding method, with low production efficiency and difficult to meet the mass production requirements of the fourth-generation nuclear reactor. The laser welding technology with high welding energy density, high welding efficiency and easy to realize automated production has become an ideal method for high-quality and high-efficiency welding production of reactor pressure vessels.
[0004] Nickel-based alloys, especially GH3535 alloy, as nickel-based superalloy materials, during the welding process, the high-viscosity liquid metal will affect the fluidity and wettability of the welding molten pool, making it easy for the weld to have welding defects such as positive collapse and back bead. And due to the intense process of high-power laser welding, excessive evaporation in local areas, violent fluctuations of the welding molten pool and collapse of the keyhole, at the same time, the high-viscosity liquid metal is difficult to backfill in time, further increasing the tendency of weld forming defects and reducing the weld forming quality. Facing such forming defects, the currently commonly used method is to empirically adjust welding process parameters, which cannot give a clear direction for process optimization and requires multiple adjustments of welding process parameters, making it difficult to achieve effective control of welding defects. Summary of the Invention
[0005] In order to solve the forming problems such as positive collapse and back bead in the welds of the welded plates obtained by the welding method of nickel-based alloys in the prior art, the present invention provides a nickel-based alloy plate and a welding method thereof. The welds of the obtained welded plates have excellent forming quality.
[0006] The present invention provides a welding method for a nickel-based alloy plate, which comprises the following preparation steps:
[0007] S1. Pre-weld the weld surface of the plate to be welded by using a full-penetration laser welding method to obtain an initial full-penetration laser weld; wherein, the plate to be welded comprises a butt-jointed first nickel-based alloy plate and a second nickel-based alloy plate, and the butt-joint of the first nickel-based alloy plate and the second nickel-based alloy plate is the weld surface; the weld surface is in an inert gas atmosphere, and the inert gas comprises a front inert gas, a side inert gas and a back inert gas;
[0008] The process parameters of the pre-welding include: the defocus amount is -1 to -12 mm, the laser power is 9 to 12 kW, the welding speed is 0.6 to 1.2 m / min, and the spot diameter is 0.1 to 0.4 mm;
[0009] S2. Judge the type of surface defects in the initial full-penetration laser weld, and adjust based on the type of the surface defects on the basis of the process parameters of the pre-welding to obtain the welding process parameters;
[0010] Wherein, the surface defect is a front collapse defect, and the adjustment direction is to reduce the energy density; or, the surface defect is a back weld bead defect, and the adjustment direction is to increase the energy density;
[0011] S3. Weld the weld surface including the initial full-penetration laser weld according to the welding process parameters to obtain a final full-penetration laser weld.
[0012] In the present invention, the full-penetration laser welding method means that during the welding process, the molten metal completely penetrates the entire thickness of the workpiece to be welded, forming a continuous weld to ensure that the joint strength is consistent with that of the base material.
[0013] In step S2, the method of reducing the energy density is preferably to reduce the laser power and / or increase the welding speed.
[0014] In some embodiments, in step S2, when the surface defect is a front collapse defect, the method of reducing the energy density is to reduce the laser power, and the reduction range of the laser power is 0.3 to 1 kW, for example, 0.5 kW.
[0015] In some embodiments, in step S2, when the surface defect is a front collapse defect, the method of reducing the energy density is to increase the welding speed, and the increase range of the welding speed is 0.2 - 0.6 m / min, for example, 0.3 m / min or 0.6 m / min.
[0016] In step S2, the method of increasing the energy density is preferably one or more of increasing the laser power, reducing the welding speed and reducing the spot diameter.
[0017] In some embodiments, in step S2, the surface defect is a back bead defect, the way to increase the energy density is to increase the laser power, and the increase range of the laser power is 0.3 - 1 kW, for example, 0.5 kW.
[0018] In some embodiments, in step S2, the surface defect is a back bead defect, the way to increase the energy density is to reduce the welding speed, and the reduction range of the welding speed is 0.2 - 0.9 m / min, for example, 0.6 m / min.
[0019] In some embodiments, in step S2, the surface defect is a back bead defect, the way to increase the energy density is to reduce the spot diameter, and the reduction range of the spot diameter is 0.1 - 0.3 mm, for example, 0.1 mm or 0.2 mm.
[0020] In step S1, the defocus amount is preferably -3 to -8 mm, for example, -5 mm. Generally, the defocus amount is divided into positive defocus amount and negative defocus amount, where "+" represents positive defocus amount and "-" represents negative defocus amount.
[0021] In step S1, the laser power is preferably 8.5 - 10 kW, for example, 9 kW or 9.5 kW.
[0022] In step S1, the welding speed is preferably 0.6 - 0.8 m / min or 0.9 - 1.2 m / min, for example, 0.7 m / min, 1.0 m / min or 1.1 m / min.
[0023] In step S1, the spot diameter is preferably 0.2 - 0.4 mm, for example, 0.3 mm.
[0024] In some preferred embodiments, in step S1, the process parameters of the pre-welding include: the laser power is 10 - 12 kW, preferably 11 - 12 kW, for example, 11.5 kW, and the welding speed is 0.6 - 0.8 m / min, for example, 0.7 m / min.
[0025] In some preferred embodiments, in step S1, the process parameters of the pre-welding include: the laser power is 9 - 10 kW, for example, 9.5 kW, and the welding speed is 0.8 - 1.2 m / min, preferably 1.0 - 1.2 m / min, for example, 0.9 m / min or 1.1 m / min.
[0026] In some specific embodiments, in step S1, the process parameters of the pre-welding include: the defocus amount is -5 mm, the laser power is 10 kW, the welding speed is 0.6 m / min, and the spot diameter is 0.4 mm.
[0027] In some specific embodiments, in step S1, the process parameters of the pre-welding include: the defocus amount is -5 mm, the laser power is 9.5 kW, the welding speed is 1.2 m / min, and the spot diameter is 0.4 mm.
[0028] In some specific embodiments, in step S1, the process parameters of the pre-welding include: the defocus amount is -5 mm, the laser power is 9.5 kW, the welding speed is 0.9 m / min, and the spot diameter is 0.4 mm.
[0029] In some specific embodiments, in step S1, the process parameters of the pre-welding include: the defocus amount is -5 mm, the laser power is 9.5 kW, the welding speed is 1.2 m / min, and the spot diameter is 0.4 mm.
[0030] In some specific embodiments, in step S3, the process parameters of the welding include: the defocus amount is -5 mm, the laser power is 9.5 kW, the welding speed is 0.6 m / min, and the spot diameter is 0.4 mm.
[0031] In some specific embodiments, in step S3, the process parameters of the welding include: the defocus amount is -5 mm, the laser power is 9.5 kW, the welding speed is 0.9 m / min, and the spot diameter is 0.3 mm.
[0032] In some specific embodiments, in step S3, the process parameters of the welding include: the defocus amount is -5 mm, the laser power is 9.5 - 10 kW, the welding speed is 1.2 m / min, and the spot diameter is 0.4 mm.
[0033] In step S1, the material of the first nickel-based alloy plate is preferably nickel-chromium alloy, nickel-chromium-molybdenum alloy, nickel-chromium-iron alloy or nickel-chromium-molybdenum-iron alloy; the nickel-chromium-molybdenum-iron alloy is preferably Ni-16Mo-7Cr-4Fe, such as GH3535 alloy.
[0034] In step S1, the material of the second nickel-based alloy plate is preferably nickel-chromium alloy, nickel-chromium-molybdenum alloy, nickel-chromium-iron alloy or nickel-chromium-molybdenum-iron alloy; the nickel-chromium-molybdenum-iron alloy is preferably Ni-16Mo-7Cr-4Fe, such as GH3535 alloy.
[0035] In step S1, the width of the surface to be welded is preferably 4 - 20 mm, for example, 10 mm or 15 mm. The width of the surface to be welded refers to the dimension of the surface to be welded along the incident direction of the laser beam. The width of the surface to be welded is also the thickness of the plate to be welded. A nickel-based alloy plate within this thickness range can generate a stable and penetrating keyhole during the welding process of the present invention, and the obtained nickel-based alloy plate has excellent forming quality and good mechanical properties.
[0036] In step S1, the length of the surface to be welded is preferably 150 - 200 mm, for example, 180 mm. The length of the surface to be welded refers to the distance that the laser beam travels along the welding direction. The length of the surface to be welded is also the length of the plate to be welded.
[0037] In step S1, preferably, the proportion of the length of the initial full-penetration laser weld to the length of the surface to be welded is 50% - 100%, for example, 100%.
[0038] In step S3, the length of the final full-penetration laser weld is generally equal to the length of the surface to be welded.
[0039] In step S1, the laser used for pre-welding is generally an adjustable laser conventionally used in the art, preferably a fiber laser, a CO2 laser, or a semiconductor laser. After the laser emits light, the laser propagates through an optical fiber, is focused by a laser welding head, and finally propagates to the surface of the workpiece for welding.
[0040] In step S1, the preparation method of the plate to be welded can be a conventional preparation method for the plate to be welded used for welding in the art, preferably including the following steps: butt-joining a first nickel-based alloy plate and a second nickel-based alloy plate and fixing them to obtain the plate to be welded.
[0041] In some embodiments, before butt-joining, the gap between the surfaces to be welded of the first nickel-based alloy plate and the second nickel-based alloy plate is preferably 0 - 0.1 mm, more preferably 0 - 0.05 mm. The gap refers to the distance between the surfaces to be welded of the first nickel-based alloy plate and the second nickel-based alloy plate.
[0042] In some embodiments, before butt-joining, the misalignment amount of the surfaces to be welded of the first nickel-based alloy plate and the second nickel-based alloy plate is preferably 0 - 1 mm. The misalignment amount refers to the difference in the thickness direction between the surfaces to be welded of the first nickel-based alloy plate and the second nickel-based alloy plate.
[0043] In some embodiments, before butt-joining, a pretreatment step is further included. The pretreatment step is conventional in the art and generally includes a machining step and a cleaning step for the surface to be welded.
[0044] Among them, the purpose of machining the surface to be welded is to make the surface to be welded flat, so that the end face gap and misalignment after butt joint of the surface to be welded are controlled within a certain range.
[0045] Among them, the cleaning is preferably carried out by wiping the surface to be welded with acetone. Specifically: wipe the surface of the workpiece within 50 mm from the weld seam in one direction with a cleaning cloth sprayed with acetone cleaning agent, and wipe the entire butt joint surface in one direction.
[0046] Among them, preferably, a fixture is used to butt the first nickel-based alloy plate and the second nickel-based alloy plate. The fixture can be conventional in the art.
[0047] Among them, the fixing method is preferably spot welding. Among them, the laser power of the spot welding is preferably 3-5 kW, for example 4 kW; the light output time of the spot welding is preferably 400-800 ms, for example 400 ms; preferably, 2-4 fixing points are set for the spot welding.
[0048] In step S1, the vertical distance between the outlet of the front protective gas and the upper surface of the plate to be welded is preferably 3-7 mm, more preferably 3-5 mm, for example 3 mm. The upper surface of the plate to be welded refers to the surface close to the laser beam.
[0049] In step S1, the front protective gas can be provided by a drag shield protection device, and the gas outlet direction of the drag shield protection device is perpendicular to the plate to be welded; the vertical distance between the lower surface of the drag shield protection device and the upper surface of the plate to be welded is preferably 3-7 mm, for example 3 mm. The lower surface of the drag shield protection device is parallel to the upper surface of the plate to be welded to ensure a uniform protective gas atmosphere above the plate to be welded. The lower surface of the drag shield protection device refers to the surface close to the plate to be welded.
[0050] In step S1, the horizontal distance between the outlet of the side protective gas and the laser beam is preferably 2-5 mm, more preferably 2-3 mm, for example 2 mm.
[0051] In step S1, the side protective gas can be provided by a side blowing protection device, and the gas outlet direction of the side blowing protection device is perpendicular to the direction of the laser beam; the horizontal distance between the side blowing protection device and the laser beam is preferably 2-5 mm, for example 2 mm.
[0052] In the present invention, the back protective gas is provided by a back protection device, and the back protection device is preferably a copper backing plate. The back protective gas can be realized by inputting and discharging the protective gas through hoses at both ends of the copper backing plate.
[0053] Preferably, after the inside of the back protection device is filled with a protective gas, the pre-welding is carried out.
[0054] In step S1, the types of the front protective gas, the side protective gas, and the back protective gas are inert protective gases for conventional welding, preferably including one or more of nitrogen, argon, and helium.
[0055] In step S1, the protective gas can be introduced by introducing the protective gas into the protective gas hoses connected to the respective protection devices.
[0056] In step S1, the gas flow rate of the side protective gas is preferably 3 - 15 L / min, for example, 10 L / min.
[0057] In step S1, the gas flow rate of the front protective gas is preferably 30 - 45 L / min, for example, 35 L / min.
[0058] In step S1, before the pre-welding, the gas flow rate of the back protective gas is preferably 20 - 45 L / min, for example, 40 L / min.
[0059] In step S1, during the pre-welding, the gas flow rate of the back protective gas is preferably 3 - 5 L / min, for example, 5 L / min.
[0060] In step S3, during the welding, the gas flow rate of the back protective gas is preferably 3 - 5 L / min, for example, 5 L / min.
[0061] In the present invention, the laser beam for the pre-welding and / or the welding preferably adopts a perpendicular incidence manner. Herein, "perpendicular incidence" means that the laser beam is incident along a direction perpendicular to the plate to be welded.
[0062] In the present invention, the pre-welding and / or the welding preferably adopt single-sided laser.
[0063] The present invention also provides a nickel-based alloy plate obtained by the laser welding method as described above.
[0064] On the basis of conforming to the common knowledge in the art, the above preferred conditions can be combined arbitrarily to obtain various preferred examples of the present invention.
[0065] The reagents and raw materials used in the present invention are all commercially available.
[0066] The positive and progressive effects of the present invention are as follows:
[0067] Compared with the existing welding technologies for nickel-based alloy plates, the present invention provides a laser welding method that can, according to the types of defects actually generated during welding, ensure the stable penetration of the keyhole through the molten pool during the full penetration laser welding of nickel-based alloys by directionally adjusting the laser deep penetration welding energy density, thereby eliminating welding forming defects and obtaining high-quality formed welds. This laser welding method is particularly applicable to GH3535 alloys with a medium thickness (thickness of 4 - 15 mm). When there are front surface collapse defects in the full penetration laser welds of medium thickness GH3535 alloys, reducing the laser power or increasing the welding speed can most significantly improve the stability of the keyhole and achieve the best defect elimination effect, resulting in excellent weld forming quality; when there are back surface hump defects in the full penetration laser welds of medium thickness GH3535 alloys, increasing the laser power, increasing the welding speed or reducing the spot diameter can most significantly improve the stability of the keyhole and achieve the best defect elimination effect, resulting in excellent weld forming quality. Description of the Drawings
[0068] Figure 1 It is a schematic structural diagram of the front surface protection device.
[0069] Reference numerals: shielding gas hose 1; side-blowing protection device 2; trailing shield protection device 3; outlet direction of the side-blowing shielding gas 4; laser beam 5; horizontal distance between the side-blowing protection device and the laser beam 6; vertical distance between the lower surface of the trailing shield protection device and the upper surface of the plate to be welded 7; plate to be welded 8.
[0070] Figure 2 It is a schematic structural diagram of the copper backing plate of the back surface protection device.
[0071] Figure 3 It is an effect diagram of eliminating the front surface collapse defect of the weld in Example 1. (a) - (c) are respectively the effect diagrams of the front surface forming, back surface forming and X-ray of the weld when the laser power is 10 kW, and (d) - (f) are respectively the effect diagrams of the front surface forming, back surface forming and X-ray of the weld when the laser power is 9.5 kW.
[0072] Figure 4 It is an effect diagram of eliminating the back surface hump defect of the weld in Example 2. (a) - (c) are respectively the effect diagrams of the front surface forming, back surface forming and X-ray of the weld when the welding speed is 1.2 m / min, and (d) - (f) are respectively the effect diagrams of the front surface forming, back surface forming and X-ray of the weld when the laser power is 0.6 m / min.
[0073] Figure 5 It is an effect diagram of eliminating the back surface hump defect of the weld in Example 3. (a) - (b) are respectively the effect diagrams of the front surface forming and back surface forming of the weld when the spot diameter is 0.4 mm, and (c) - (d) are respectively the effect diagrams of the front surface forming and back surface forming of the weld when the spot diameter is 0.3 mm.
[0074] Figure 6 It is the effect diagram of eliminating the bead defect on the back of the weld in Example 4.
[0075] Figure 7 It is the schematic diagram of the weld formation in Comparative Example 1. (a) is the formation on the front of the weld, and (b) is the formation on the back of the weld.
[0076] Figure 8 It is the schematic diagram of the weld formation in Comparative Example 2. (a) is the formation on the front of the weld, and (b) is the formation on the back of the weld. Detailed implementation manners
[0077] The present invention will be further described below by way of examples, but the present invention is not limited to the scope of the described examples. For the experimental methods without specific conditions in the following examples, they are carried out according to conventional methods and conditions, or selected according to the product specifications.
[0078] In the following examples and comparative examples, the nickel-based alloy plate used is a nickel-chromium-molybdenum-iron alloy (Ni-16Mo-7Cr-4Fe), specifically GH3535 alloy.
[0079] Example 1
[0080] In this example, the test material is a GH3535 alloy welding plate with a thickness of 10 mm and a length of 180 mm.
[0081] S1. Pre-welding:
[0082] (1) Take two 10-mm-thick GH3535 alloy welding plates, and use wire cutting to process the butt joint surface smoothly. Grind the butt joint surface and wipe the surface of the welding plate within 50 mm from the butt joint surface in one direction with a cleaning cloth sprayed with acetone cleaning agent. Wipe the entire butt joint surface in one direction and dry it;
[0083] (2) Place the two GH3535 welding plates that have been cleaned, dried and then ground in butt joint with the length sides (the butt joint is the surface to be welded, the length of the surface to be welded is 180 mm, and the width is 10 mm) on the welding workbench, and fix them with welding jigs. The jig body is a threaded hole cast iron plate with a copper protection gas groove, equipped with parallel pressing blocks. Fix the GH3535 welding plates at the four corners around the welded area through the pressing blocks to ensure that there is no gap between the two GH3535 welding plates, the misalignment amount is 0, and spot weld the welding plates. The spot welding fixing method uses laser spot fixing, set 2 fixing points, which are respectively at both ends of the surface to be welded. The laser power for spot welding fixing is 4 kW, and the light emission time is 400 ms; obtain the plate to be welded 8;
[0084] (3) Install the front protection device (side-blowing protection device 2 and trailing shield protection device 3) around the fixed plate to be welded 8 (as Figure 1 shown). The outlet direction 4 of the side protection gas provided by the side-blowing protection device 2 is perpendicular to the direction of the laser beam 5, and the horizontal distance 6 between the side-blowing protection device and the laser beam is 2 mm; the lower surface (the surface close to the plate to be welded) of the trailing shield protection device 3 should be parallel to the upper surface (the surface close to the laser beam) of the plate to be welded 8. The outlet direction of the front protection gas provided by the trailing shield protection device 3 is parallel to the welding surface, and the vertical distance 7 between the lower surface of the trailing shield protection device and the upper surface of the plate to be welded is 3 mm. Use the back protection device, the copper backing plate, to block both ends of the welding surface on the back of the plate to be welded (as Figure 2 shown), and set the protection gas hose accordingly. Pass nitrogen protection gas through the protection gas hoses connected to each protection device. Among them, the gas flow rate in the protection gas hose 1 connected to the side-blowing protection device is controlled at 10 L / min, the gas flow rate in the protection gas hose 1 connected to the trailing shield protection device is controlled at 35 L / min, and the gas flow rate of the back protection gas is controlled at 40 L / min before welding. After inflating for 10 min, when the inside of the copper backing plate is filled with nitrogen protection gas, convert the back protection gas flow rate to 5 L / min.
[0085] (4) Select to use a fiber laser, and set the pre-welding process parameters as follows: the spot diameter is 0.4 mm, the defocus amount is -5 mm, the laser power is 10 kW, and the welding speed is 0.6 m / min;
[0086] Perform pre-welding on the plate to be welded 8 to obtain an initial full-penetration laser weld (length is 180 mm).
[0087] S2. Judge the type of surface defect and adjust the welding parameters:
[0088] Determine that the surface defect of the initial full-penetration laser weld is the collapse on the front of the weld; reduce the laser power, and the reduction range is 500 W to reduce the welding energy density. Specifically, the welding parameters are adjusted as follows: the spot diameter is 0.4 mm, the defocus amount is -5 mm, the laser power is 9.5 kW, and the welding speed is 0.6 m / min.
[0089] S3. Perform welding:
[0090] According to the welding parameters set in step S2, perform welding on the initial full-penetration laser weld to obtain a final full-penetration laser weld (length is 180 mm), and obtain a nickel-based alloy plate.
[0091] Example 2
[0092] In this example, the test material is a GH3535 alloy welding plate with a thickness of 10 mm and a length of 180 mm.
[0093] The difference between this embodiment and Embodiment 1 is as follows:
[0094] S1. Pre-welding: (4) The laser power is 9.5 kW and the welding speed is 1.2 m / min;
[0095] S2. Determine the type of surface defect and adjust the welding parameters: It is determined that the surface defect of the initial full-penetration laser weld is a weld root bead on the back of the weld; reduce the welding speed, with a reduction amplitude of 0.6 m / min, and increase the welding energy density. Specifically, the welding parameters are adjusted to: the laser power is 9.5 kW and the welding speed is 0.6 m / min;
[0096] The remaining conditions are the same as those in Embodiment 1.
[0097] Embodiment 3
[0098] In this example, the test material is a GH3535 alloy welding plate with a thickness of 10 mm and a length of 180 mm.
[0099] The difference between this embodiment and Embodiment 1 is as follows:
[0100] S1. Pre-welding: (4) The laser power is 9.5 kW and the welding speed is 0.9 m / min;
[0101] S2. Determine the type of surface defect and adjust the welding parameters: It is determined that the surface defect of the initial full-penetration laser weld is a weld root bead on the back of the weld; reduce the spot diameter, with a reduction amplitude of 0.1 mm, and increase the welding energy density. Specifically, the welding parameters are adjusted to: the spot diameter is 0.3 mm and the welding speed is 0.9 m / min;
[0102] The remaining conditions are the same as those in Embodiment 1.
[0103] Embodiment 4
[0104] In this example, the test material is a GH3535 alloy welding plate with a thickness of 10 mm and a length of 180 mm.
[0105] The difference between this embodiment and Embodiment 1 is as follows:
[0106] S1. Pre-welding: (4) The laser power is 9.5 kW and the welding speed is 1.2 m / min;
[0107] S2. Determine the type of surface defect and adjust the welding parameters: It is determined that the surface defect of the initial full-penetration laser weld is a weld root bead on the back of the weld; slowly increase the laser power, with an increase amplitude of 0.5 kW, and increase the welding energy density. Specifically, the welding parameters are adjusted to: the laser power slowly rises from 9.5 kW to 10 kW and the welding speed is 1.2 m / min;
[0108] The remaining conditions are the same as those in Example 1.
[0109] Comparative Example 1
[0110] Based on Example 1, for the surface defect of the initial full-penetration laser weld being a positive collapse defect, in this comparative example, in step S2, the welding speed is decreased by 0.3 m / min, and the welding energy density is increased. Specifically, the welding parameters are adjusted as follows: the laser power is 10 kW, and the welding speed is 0.3 m / min; the remaining conditions are the same as those in Example 1.
[0111] Comparative Example 2
[0112] Based on Example 2, for the surface defect of the initial full-penetration laser weld being a back bead defect, in this comparative example, in step S2, the laser power is decreased by 500 W, and the welding energy density is decreased. Specifically, the welding parameters are adjusted as follows: the laser power is 9 kW, and the welding speed is 1.2 m / min; the remaining conditions are the same as those in Example 2.
[0113] Effect Example 1
[0114] The forming conditions of the welds on the surface and back of the nickel-based alloy plates obtained by the welding methods of the nickel-based alloy plates in Examples 1-4 and Comparative Examples 1-2 above were respectively obtained by direct photography, and the internal defect conditions were obtained by X-ray detection, and Figures 3 - 8 .
[0115] Among them, the X-ray detection was carried out with reference to the American Society of Mechanical Engineers standard ASME BPVC-V-2017, and X-ray detection images were obtained.
[0116] The welds obtained after pre-welding and welding in Example 1 and Example 2 were respectively subjected to X-ray detection, and the X-ray detection images are respectively as shown in Figure 3 (c), (f) in Figure 4 (c), (f) in.
[0117] According to Figure 3 it can be seen that by using the welding method in Example 1, for the positive collapse defect of the full-penetration weld of the 10-mm-thick GH3535 alloy plate, the laser power can be decreased by 0.5 kW, the welding energy density can be reduced, the full-penetration welding keyhole of the GH3535 alloy can be stabilized, and the defect can be completely eliminated. The formed quality of the obtained weld is excellent, and there are no internal forming defects such as pores.
[0118] According to Figure 4It can be seen that for the back bead defect of the full penetration weld of the 10-mm-thick GH3535 alloy plate using the welding method in Example 2, the defect can be completely eliminated by reducing the welding speed by 0.6 m / min, increasing the welding energy density, and stabilizing the full penetration welding keyhole of the GH3535 alloy. The obtained weld has high-quality forming and no internal forming defects such as pores.
[0119] According to Figure 5 It can be seen that for the back bead defect of the full penetration weld of the 10-mm-thick GH3535 alloy plate using the welding method in Example 3, the defect can be completely eliminated and the forming quality is excellent by increasing the welding energy density and stabilizing the full penetration welding keyhole of the GH3535 alloy by reducing the spot diameter.
[0120] According to Figure 6 It can be seen that for the back bead defect of the full penetration weld of the 10-mm-thick GH3535 alloy plate using the welding method in Example 4, the defect can be completely eliminated and the forming quality is excellent by increasing the welding energy density and stabilizing the full penetration welding keyhole of the GH3535 alloy by gradually increasing the laser power.
[0121] The weld formed by the welding method in Comparative Example 1 is as Figure 7 shown. It can be found that for the front surface collapse, the weld formed by increasing the energy density has poor forming quality and the defect cannot be completely eliminated.
[0122] The weld formed by the welding method in Comparative Example 2 is as Figure 8 shown. It can be found that for the back bead defect, the weld formed by reducing the energy density has poor forming quality and the defect cannot be completely eliminated.
[0123] Effect Example 2
[0124] Based on the welding method of the nickel-based alloy plate provided by the present invention, the nickel-based alloy plate obtained by welding using the optimized process parameters in Example 3 is used as a specimen, and an Instron electronic universal testing machine (model instron 5980) is used to conduct a room-temperature tensile test on the welded joint of the obtained specimen. Three groups of tensile tests are carried out, and the results are shown in Table 1 below.
[0125] Table 1
[0126]
[0127] Among them, the detection basis for mechanical property testing refers to AWS B4.0M:2000(R2010). Among them, the yield strength is the stress value at which the specimen produces a 0.2% residual deformation, the maximum force is the maximum load when the specimen does not break during the tensile process, the elongation after fracture is the percentage of the length by which the gauge part of the specimen elongates when the specimen fractures during tensile testing compared to the original gauge length, and the reduction of area is the percentage of the maximum reduced area of the cross-section when the specimen fractures during tensile testing compared to the original cross-sectional area.
[0128] As can be seen from Table 1, the welded joints of the nickel-based alloy plates obtained by the welding method of the present invention have excellent strength performance. The tensile strength at room temperature > 690 MPa, the yield strength > 280 MPa. In Comparative Examples 1-2, the forming quality is poor, the tensile strength of the joints is generally lower than 100 MPa, and the elongation after fracture is less than 10%, or fractures directly occur during the tensile process, and specific tensile test data cannot be measured.
[0129] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that this is only an example. The protection scope of the present invention is defined by the appended claims. Without departing from the principles and essence of the present invention, those skilled in the art can make various changes or modifications to these embodiments, but these changes and modifications all fall within the protection scope of the present invention.
Claims
1. A welding method for a nickel-based alloy plate, characterized in that, It includes the following preparation steps: S1. Pre-weld the surface to be welded of the plate to be welded by using the full-penetration laser welding method to obtain an initial full-penetration laser weld seam; wherein, the plate to be welded includes a butt-jointed first nickel-based alloy plate and a second nickel-based alloy plate, and the butt-joint of the first nickel-based alloy plate and the second nickel-based alloy plate is the surface to be welded; the surface to be welded is in an inert gas atmosphere, and the inert gas includes a front inert gas, a side inert gas and a back inert gas; The process parameters of the pre-welding include: the defocus amount is -1~-12 mm, the laser power is 9~12 kW, the welding speed is 0.6~1.2 m / min, and the spot diameter is 0.1~0.4 mm; S2. Judge the type of surface defects in the initial full-penetration laser weld seam, and adjust based on the type of the surface defects on the basis of the process parameters of the pre-welding to obtain the welding process parameters; Wherein, the surface defect is a front collapse defect, and the adjustment direction is to reduce the energy density; or, the surface defect is a back weld bead defect, and the adjustment direction is to increase the energy density; S3. Weld the surface to be welded including the initial full-penetration laser weld seam according to the welding process parameters to obtain a final full-penetration laser weld seam.
2. The welding method of the nickel-based alloy plate according to claim 1, characterized in that, In step S2, the way to reduce the energy density is to reduce the laser power and / or increase the welding speed.
3. The welding method of the nickel-based alloy plate as claimed in claim 2, wherein In step S2, the surface defect is a front collapse defect, the way to reduce the energy density is to reduce the laser power, and the reduction range of the laser power is 0.3~1 kW; Or, in step S2, the surface defect is a front collapse defect, the way to reduce the energy density is to increase the welding speed, and the increase range of the welding speed is 0.2~0.6 m / min.
4. The welding method of the nickel-based alloy plate according to claim 1, characterized in that, In step S2, the way to increase the energy density is to increase the laser power, reduce the welding speed and reduce the spot diameter alone or in combination.
5. The welding method of the nickel-based alloy plate as claimed in claim 4, wherein In step S2, the surface defect is a back weld bead defect, the way to increase the energy density is to increase the laser power, and the increase range of the laser power is 0.3~1 kW; Or, in step S2, the surface defect is a back weld bead defect, the way to increase the energy density is to reduce the welding speed, and the reduction range of the welding speed is 0.2~0.9 m / min; Or, in step S2, the surface defect is a back weld bead defect, the way to increase the energy density is to reduce the spot diameter, and the reduction range of the spot diameter is 0.1~0.3 mm.
6. The welding method of the nickel-based alloy plate according to claim 1, characterized in that, In step S1, the process parameters of the pre-welding satisfy one or more of the following conditions (a)-(d): (a) The defocus amount is -3~-8 mm, for example, -5 mm; (b) The laser power is 8.5~10 kW, for example, 9 kW or 9.5 kW; (c) The welding speed is 0.6 - 0.8 m / min or 0.9 - 1.2 m / min, for example 0.7 m / min, 1.0 m / min or 1.1 m / min; (d) The spot diameter is 0.2 - 0.4 mm, for example 0.3 mm.
7. The welding method of the nickel-based alloy plate according to claim 1, characterized in that In step S1, the process parameters of the pre-welding include: the laser power is 10 - 12 kW, preferably 11 - 12 kW, for example 11.5 kW, and the welding speed is 0.6 - 0.8 m / min, for example 0.7 m / min; Or, in step S1, the process parameters of the pre-welding include: the laser power is 9 - 10 kW, for example 9.5 kW, and the welding speed is 0.8 - 1.2 m / min, preferably 1.0 - 1.2 m / min, for example 0.9 m / min or 1.1 m / min.
8. The welding method of the nickel-based alloy plate according to claim 1, characterized in that In step S1, the width of the surface to be welded is 4 - 20 mm, for example 10 mm or 15 mm; And / or, in step S1, the length of the surface to be welded is 150 - 200 mm, for example 180 mm; And / or, in step S1, the proportion of the length of the initial full-penetration laser weld seam to the length of the surface to be welded is 40% - 100%, preferably 50% - 100%; And / or, in step S1, the material of the first nickel-based alloy plate is nickel-chromium alloy, nickel-chromium-molybdenum alloy, nickel-chromium-iron alloy or nickel-chromium-molybdenum-iron alloy; the nickel-chromium-molybdenum-iron alloy is preferably Ni-16Mo-7Cr-4Fe, for example GH3535 alloy; And / or, in step S1, the material of the second nickel-based alloy plate is nickel-chromium alloy, nickel-chromium-molybdenum alloy, nickel-chromium-iron alloy or nickel-chromium-molybdenum-iron alloy; the nickel-chromium-molybdenum-iron alloy is preferably Ni-16Mo-7Cr-4Fe, for example GH3535 alloy.
9. The welding method of the nickel-based alloy plate according to claim 1, characterized in that In step S1, the types of the front protective gas, side protective gas and back protective gas are inert protective gases, preferably including one or more of nitrogen, argon and helium; And / or, in step S1, the gas flow rate of the front protective gas is 30 - 45 L / min; And / or, before the pre-welding in step S1, the gas flow rate of the back protective gas is 20 - 45 L / min; And / or, in step S1, the gas flow rate of the side protective gas is 3 - 5 L / min; And / or, in step S1, the gas flow rate of the back protective gas during the pre-welding is 3 - 5 L / min; And / or, in step S3, the gas flow rate of the back protective gas during the welding is 3 - 5 L / min; And / or, in step S1, the method for preparing the plate to be welded includes the following steps: butt-join a first nickel-based alloy plate and a second nickel-based alloy plate and fix them to obtain the plate to be welded; wherein, after the butt-joining, the gap between the welding surfaces of the first nickel-based alloy plate and the second nickel-based alloy plate is preferably 0 to 0.1 mm, more preferably 0 to 0.05 mm; after the butt-joining, the misalignment amount of the welding surfaces of the first nickel-based alloy plate and the second nickel-based alloy plate is preferably 0 to 1 mm; preferably, a pretreatment step is further included before the butt-joining, and the pretreatment step includes a machining step and a cleaning step for the welding surfaces; preferably, a fixture is used to butt-join the first nickel-based alloy plate and the second nickel-based alloy plate. And / or, in step S1, the laser used for the welding is an adjustable laser, preferably a fiber laser, a CO2 laser or a semiconductor laser.
10. A nickel-based alloy plate, characterized in that, It is prepared by the laser welding method according to any one of claims 1-9.