Nickel-based alloy plate and laser wire filling welding method thereof

Abstract

The invention discloses a nickel-based alloy plate and a laser filler wire welding method thereof, a to-be-welded surface of a first nickel-based alloy plate and a to-be-welded surface of a second nickel-based alloy plate are in butt joint and fixed to obtain a to-be-welded plate, a V-shaped groove is arranged at the butt joint surface of the first nickel-based alloy plate and the second nickel-based alloy plate, and the bilateral angle of the V-shaped groove is 8-10 degrees; the truncated edge of the V-shaped groove is welded, and a preliminary welding plate is obtained; and under protective gas, the V-shaped groove of the preliminary welding plate is filled with laser filler wire welding till the V-shaped groove is fully filled, the welding method can well restrain the welding solidification crack defect, the welding seam quality meets the national standard, and a welded joint has good mechanical performance.

Description

Technical Field

[0001] The invention relates to a nickel-based alloy plate and a laser wire-filling welding method thereof. Background Art

[0002] As one of the candidate reactor types for the fourth-generation nuclear reactor, the molten salt reactor (MSR) has attracted more and more attention from the nuclear power industry due to its safer, more efficient and more sustainable structural design. GH3535 nickel-based alloy has excellent corrosion resistance and high-temperature mechanical properties, and is used as a structural material for molten salt reactors. Due to the harsh service conditions of molten salt reactors, key equipment such as the main container is often manufactured by welding thick plate structural materials. However, nickel-based alloys have poor welding fluidity, and defects such as high-temperature solidification cracking and unfused welding often occur during the welding process, which seriously endangers the mechanical and service properties of the welded joints. At the same time, traditional arc welding methods are inefficient and require layer-by-layer grinding, which seriously affects the manufacturing progress of reactor components.

[0003] At present, the main problems in welding GH3535 nickel-based alloy are:

[0004] (1) Weld solidification cracking problem. GH3535 nickel-based alloy often suffers from solidification cracking during laser wire welding, which seriously endangers the mechanical properties and service safety of the welded joint;

[0005] (2) Interlayer grinding pollution problem. Nickel-based alloys are easily oxidized during the welding process. Traditional arc welding requires mechanical grinding to remove the oxide layer for each layer. The welding efficiency is low and the dust pollution is serious, which brings great inconvenience and harm to the on-site assembly environment and construction personnel.

[0006] (3) Poor fusion of nickel-based alloys in narrow gaps. Nickel-based alloys are prone to poor melting and fusion in narrow gap groove welding due to poor molten metal fluidity and narrow light wire energy matching window, which can easily lead to unqualified weld joint quality. Summary of the invention

[0007] The purpose of the present invention is to solve the problem that the existing thick plate narrow gap nickel-based alloy plate welding requires interlayer grinding and the weld is prone to defects, and to provide a nickel-based alloy plate and a laser wire welding method thereof. The welding method of the present invention can effectively suppress defects in the weld and obtain a weld without solidification cracking and unfused defects.

[0008] The present invention solves the above technical problems through the following technical solutions:

[0009] The invention discloses a laser wire-filling welding method for a nickel-based alloy plate, which comprises the following steps:

[0010] (1) butting the surfaces to be welded of the first nickel-based alloy plate and the second nickel-based alloy plate and fixing them to obtain plates to be welded;

[0011] A V-shaped groove is provided at the butt joint surface of the first nickel-based alloy plate and the second nickel-based alloy plate, and the bilateral angle of the V-shaped groove is 8-10°;

[0012] (2) welding the blunt edge of the V-shaped groove to obtain a preliminary weld plate;

[0013] (3) Under protective gas, the V-shaped groove of the preliminary welding plate is filled by laser wire welding until the V-shaped groove is filled; the welding parameters of the laser wire welding are: laser power is 4000~5000W, wire feeding speed is 4~5m / min, oscillating laser is used, and the oscillation frequency of the laser is 250~350Hz.

[0014] The present invention can control the depth-to-width ratio of a single-layer weld to be less than 0.72 through the coordination of groove, laser power, swinging laser and wire feeding speed, thereby obtaining a weld without crack defects.

[0015] In the present invention, in step (1), the double-sided angle of the V-shaped groove is preferably 8°, wherein the double-sided angle of the V-shaped groove refers to the angle formed by the butt surfaces of the first nickel-based alloy plate and the second nickel-based alloy plate. The single-sided angle of the V-shaped groove is preferably 4-5°, for example 4°, and the single-sided angle refers to the angle between the surface to be welded of the first nickel-based alloy plate or the second nickel-based alloy plate and the vertical surface.

[0016] In the present invention, in step (1), the V-shaped groove is a blunt-edged V-shaped groove, and the thickness of the blunt edge of the blunt-edged V-shaped groove is preferably 2-4 mm, for example 3 mm. The width of the blunt edge of the blunt-edged V-shaped groove is preferably 3-4 mm. The gap between the butt surfaces of the blunt edge of the blunt-edged V-shaped groove is preferably <0.02 mm.

[0017] In the present invention, in step (1), the thickness of the first nickel-based alloy plate and the second nickel-based alloy plate are preferably 10-50 mm, for example 30 mm. The thickness of the first nickel-based alloy plate and the second nickel-based alloy plate are generally the same.

[0018] In the present invention, in step (1), the material of the first nickel-based alloy plate and 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, and the nickel-chromium-molybdenum-iron alloy is preferably Ni-16Mo-7Cr-4Fe with a grade of GH3535.

[0019] In the present invention, in step (1), preferably, a clamp is used to butt the surfaces to be welded of the first nickel-based alloy plate and the second nickel-based alloy plate. The clamp can be conventional in the art.

[0020] Preferably, the clamp includes a base, a plurality of first clamping components and a plurality of second clamping components, a groove is arranged at the center of the base; the plurality of first clamping components are symmetrically arranged in pairs with the groove as the center, and the plurality of second clamping components are symmetrically arranged in pairs with the groove as the center.

[0021] Preferably, on each side of the groove, one second clamping component is disposed between every two adjacent first clamping components.

[0022] Preferably, the first clamping assembly includes an L-shaped bracket and a first bolt, one end of the L-shaped bracket is connected to the base, the other end of the L-shaped bracket is parallel to the upper surface of the base, and the other end of the L-shaped bracket is provided with a first bolt hole, the first bolt hole is perpendicular to the upper surface of the base, and the first bolt is arranged in the first bolt hole.

[0023] Preferably, the second clamping assembly includes a fixing block and a second bolt, the fixing block is connected to the base, a second bolt hole is provided on the fixing block, the second bolt hole is parallel to the upper surface of the base and perpendicular to the groove, and the second bolt is arranged in the second bolt hole.

[0024] When the first nickel-based alloy plate and the second nickel-based alloy plate are placed on the base, the welds to be welded of the two plates are located directly above the groove, and during welding, the back shielding gas enters from the groove to protect the back of the weld. The clamp of the present invention not only implements effective rigid constraints on the weldment to prevent welding deformation, but also can fix the welding path and constrain the splicing gap between the first nickel-based alloy plate and the second nickel-based alloy plate, and the groove is provided on the base to facilitate the application of back shielding gas.

[0025] In some embodiments of the present invention, there are 8 groups of first clamping assemblies, 6 groups of second clamping assemblies, and 4 groups of first clamping assemblies and 3 groups of second clamping assemblies on each side.

[0026] In the present invention, in step (2), preferably, laser autogenous welding is used to weld the blunt edge of the V-shaped groove under a protective gas.

[0027] Among them, the welding parameters of the laser self-fusion welding are preferably: laser power is 1500~2000 W, welding speed is 0.6~1m / min, defocus is -5~0mm, swing laser is used, swing frequency is 50~200Hz, and swing amplitude is 0.6~1mm.

[0028] Preferably, the oscillation shape of the oscillating laser is a circle shape.

[0029] Generally, the defocus amount is divided into positive defocus amount and negative defocus amount, "+" represents positive defocus amount and "-" represents negative defocus amount.

[0030] The protective gas preferably includes front protective gas, side protective gas and back protective gas. The flow rate of the front protective gas is preferably 50-70 L / min; the flow rate of the side protective gas is preferably 50-80 L / min; and the flow rate of the back protective gas is preferably 15-20 L / min.

[0031] Preferably, the back side protection gas is introduced through the groove on the aforementioned fixture.

[0032] The front shielding gas, the side shielding gas and the back shielding gas can all be conventional in the art, such as argon gas, and the purity of the argon gas is generally 99.99%.

[0033] Preferably, a protective gas delivery device is provided above the plate to be welded, a front protective gas outlet is provided at the bottom of the protective gas delivery device, and a side protective gas outlet is provided at the side of the protective gas delivery device. More preferably, the front protective gas outlet is 3-5 mm away from the upper surface of the plate to be welded, and the side protective gas outlet is 4-5 mm away from the laser beam.

[0034] In the present invention, the front shielding gas refers to the shielding gas facing the front of the plate to be welded, the side shielding gas refers to the shielding gas perpendicular to the laser direction, and the back shielding gas refers to the shielding gas facing the back of the plate to be welded.

[0035] In some embodiments of the present invention, the welding parameters of the laser self-fusion welding are: laser power is 1500W, welding speed is 0.8m / min, defocus is 0mm, Circle-type oscillating laser is used, oscillation frequency is 50Hz, and oscillation amplitude is 0.6mm; the protective gas includes front protective gas, side protective gas and back protective gas, the flow rate of the front protective gas is 50~70L / min, the flow rate of the side protective gas is 50~80L / min, and the flow rate of the back protective gas is 15~20L / min.

[0036] In the present invention, in step (2), preferably, a welding robot is used to perform laser self-melting welding, which may specifically include the following steps: adjusting the action path of the welding robot, setting the welding process parameters, and starting welding after introducing a protective gas.

[0037] In the present invention, in step (2), after welding the blunt edge of the V-shaped groove, the method may further include the steps of cleaning the weld and wiping it with ethanol.

[0038] In the present invention, in step (3), the laser power is preferably 4200-4800W, more preferably 4500W.

[0039] In the present invention, in step (3), the wire feeding speed is preferably 4.4-4.8 m / min, for example 4.5 m / min.

[0040] In the present invention, in step (3), the laser power and the wire feeding speed preferably satisfy the following condition: for every 0.1 m / min increase in the wire feeding speed, the laser power increases by 100 W.

[0041] In the present invention, in step (3), the swing amplitude of the laser is preferably 1 / 2 of the bottom width of the current weld to be filled. The current weld to be filled refers to the top width of the previous weld, for example, for the first layer of weld, the bottom width of the current weld to be filled refers to the width of the blunt edge, and for the second layer of weld, the bottom width of the current weld to be filled refers to the top width of the first layer of weld.

[0042] In the present invention, in step (3), the shape of the oscillating laser is preferably a circle shape.

[0043] In the present invention, in step (3), the welding speed of the laser wire welding is preferably 0.36-0.45 m / min, for example 0.39 m / min.

[0044] In the present invention, in step (3), the defocusing amount in the laser wire welding is preferably +5 to +10 mm.

[0045] In the present invention, in step (3), the wire feeding method of the welding wire is preferably pre-feeding.

[0046] In the present invention, in step (3), preferably, the angle between the welding wire and the preliminary welding plate is 40-45°, and the projection of the welding wire on the preliminary welding plate is parallel to the welding direction.

[0047] In the present invention, in step (3), the dry extension length of the welding wire is preferably 13-15 mm, and the dry extension length of the welding wire refers to the distance from the end of the welding wire to the end of the conductive nozzle; the diameter of the welding wire is preferably 1.1-1.2 mm.

[0048] In the present invention, in step (3), the distance between the center of the welding wire and the center of the laser beam is preferably 0-0.4 mm.

[0049] In the present invention, in step (3), the material of the welding wire can be conventional in the art, such as welding wire with a grade of ERNiMo-2.

[0050] In the present invention, in step (3), the protective gas preferably includes front protective gas and side protective gas. The flow rate of the front protective gas is preferably 60-70 L / min; the flow rate of the side protective gas is preferably 50-60 L / min.

[0051] Wherein, the front protection gas and the side protection gas can be conventional in the art, such as argon, and the purity of the argon is generally 99.99%.

[0052] Preferably, a shielding gas delivery device is provided above the preliminary welding plate, a front shielding gas outlet is provided at the bottom of the shielding gas delivery device, and a side shielding gas outlet is provided at the side of the shielding gas delivery device. More preferably, when the remaining height of the groove is greater than 10 mm, the height of the front shielding gas outlet of the shielding gas delivery device from the upper surface of the preliminary welding plate is 2 to 3 mm, and the side shielding gas outlet is 3 to 5 mm away from the laser beam; when the remaining height of the groove is 0 to 10 mm, the height of the front shielding gas outlet of the shielding gas delivery device from the preliminary welding plate is 4 to 5 mm, and the side shielding gas outlet is 3 to 5 mm away from the laser beam.

[0053] Within the above-mentioned distance range, the weld formation is relatively uniform. If the front shielding gas outlet is too close to the upper surface of the plate to be welded, spatter during welding will easily block the outlet. If it is too far, the protection effect is poor. If the side shielding gas outlet is too close to the laser beam, the laser will damage the shielding gas delivery device. If it is too far, it is impossible to effectively avoid the formation of metal plume and plasma caused by the laser, which will seriously affect the instability and poor uniformity of the weld formation.

[0054] In some embodiments of the present invention, the welding parameters of the laser wire welding are: laser power 4500W, wire feeding speed 4.5m / min, welding speed 0.39m / min, defocus amount +10mm, Circle-type oscillating laser, oscillation frequency 350Hz, oscillation amplitude 1 / 2 of the bottom width of the current weld to be filled; the shielding gas includes front shielding gas and side shielding gas, the flow rate of the front shielding gas is 60~70L / min; the flow rate of the side shielding gas is 50~60L / min.

[0055] In the present invention, in step (3), preferably, after filling the V-shaped groove, the step of capping the laser wire weld is also included. Generally, when a small-sized depression (such as a depression of 1 to 2 mm) appears on the weld surface of the laser wire weld, the depression can be filled by capping to make the weld area more saturated.

[0056] Among them, the cap welding can be conventional in the art. In some embodiments, the cap welding is preferably laser wire-filling cap welding, and the laser power of the laser wire-filling cap welding is the same as the laser power of the laser wire-filling welding in step (3) or is increased by 100~200W on the basis of the laser power of the laser wire-filling welding in step (3), and the remaining process parameters are the same as the process parameters of the aforementioned laser wire-filling welding.

[0057] When a shielding gas delivery device is provided, the height of the front shielding gas outlet of the shielding gas delivery device from the preliminary welding plate is 4-5 mm, and the height of the side shielding gas outlet from the laser beam is 3-5 mm.

[0058] In some embodiments of the present invention, the parameters of the laser wire filling and capping welding include: setting the running trajectory of the welding robot, front wire feeding, introducing the wire feeding gun at 45° to the plate and parallel to the welding direction, the dry extension length is 13mm, the welding wire is 1.2mm ERNiMo-2, the welding wire is directly in contact with the surface of the wire to be filled, and the distance between the center of the welding wire and the center of the laser beam is 0.4mm; the laser power is 4500W, the wire feeding speed is 4.5m / min, the welding speed is 0.39m / min, the defocus amount is +10mm, and a Circle-type oscillating laser is used with an oscillation frequency of 350Hz and an oscillation amplitude of 1 / 2 of the bottom width of the current weld to be filled; the protective gas is introduced, the front protective gas flow rate is 70L / min, and the side protective gas flow rate is 50L / min.

[0059] The invention also discloses a nickel-based alloy plate obtained by the above-mentioned nickel-based alloy plate laser wire-filling welding method.

[0060] In the present invention, the tensile yield strength of the welded joint of the nickel-based alloy plate at room temperature can reach 310 MPa or more, such as 310-328 MPa, the tensile strength can reach 810 MPa or more, such as 810-820 MPa, the elongation after fracture can reach 54% or more, such as 54-60%, and the cross-sectional shrinkage can reach 34-45%;

[0061] The tensile yield strength of the welded joint of the nickel-based alloy plate at 650° C. can reach 213 MPa or more, such as 213.5-220.5 MPa, the tensile strength can reach 570 MPa or more, such as 570-584.5 MPa, the elongation after fracture can reach 31.5% or more, such as 31.5-38.5%, and the cross-sectional shrinkage can reach 29-34.5%;

[0062] The tensile yield strength of the welded joint of the nickel-based alloy plate at 700° C. can reach 206 MPa or more, such as 206.5-213.5 MPa, the tensile strength can reach 528 MPa or more, such as 528.5-539 MPa, the elongation after fracture can reach 33% or more, such as 33-38.0%, and the cross-sectional shrinkage can reach 27.5-28.5%;

[0063] The welded joint of the nickel-based alloy plate can be bent sideways by 180° without generating cracks.

[0064] The positive and progressive effects of the present invention are:

[0065] The welding method of the present invention can effectively suppress welding solidification crack defects, the weld quality meets national standards, and the weld joint has good mechanical properties (including room temperature tensile properties, high temperature tensile properties and bending properties); the method of the present invention breaks through the limitation that low-power laser autogenous welding cannot weld thick plates, and the welding efficiency is increased by 5 to 10 times compared with traditional arc welding.

[0066] The invention can obtain a weld without cracks and unfused defects by coordinating the groove angle, laser power, swinging laser and wire feeding speed.

[0067] The method of the present invention further obtains a silver-bright filled weld by setting a front shielding gas and a side shielding gas, so that each layer of the weld does not need to be mechanically polished after being filled, thereby greatly reducing environmental pollution and harm. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 Schematic diagram of the groove of Example 1.

[0069] Figure 2 This is a schematic diagram of the welding process of Example 1.

[0070] Figure 3 This is a schematic diagram of the position of the protective gas delivery device of Example 1.

[0071] Figure 4 Schematic diagram of the fixture structure used in the embodiment of the present invention.

[0072] Figure 5 This is the relationship between the depth-to-width ratio of a single-layer weld and weld cracks in laser wire welding.

[0073] Figure 6 This is the front weld morphology image of the preliminary weld plate in Example 1.

[0074] Figure 7 This is the back weld morphology of the preliminary weld plate in Example 1.

[0075] Figure 8 This is the morphology of the filling weld of Example 1.

[0076] Fig. 9 This is the weld morphology after cover welding of Example 1.

[0077] Fig.10 This is the nondestructive testing result diagram of Example 1.

[0078] Fig.11 This is a metallographic image of the overall weld after cover welding in Example 1.

[0079] Fig.12 The filled weld of Example 1, wherein (a) is a morphology diagram of the filled weld, (b) is a nondestructive testing result diagram of the filled weld, and (c) is a metallographic diagram of the filled weld.

[0080] Fig.13 The filled weld of Example 2, wherein (a) is a morphology diagram of the filled weld, (b) is a nondestructive testing result diagram of the filled weld, and (c) is a metallographic diagram of the filled weld.

[0081] Fig.14 This is the metallographic image of the filled weld of Comparative Example 1.

[0082] Fig.15 This is the morphology of the 5th layer weld of Example 3.

[0083] Fig.16 This is the morphology of the 6th layer weld of Example 3.

[0084] Fig.17 This is a morphology diagram of the overall weld after cover welding in Example 4.

[0085] Fig.18 This is the result of room temperature welding mechanical test.

[0086] Fig.19 This is the result of high temperature welding mechanical test.

[0087] Fig. 20 Figure 2 is the side bending test result diagram, where (a) and (b) are the test results at different angles. DETAILED DESCRIPTION

[0088] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0089] The clamp used in the following embodiments of the present invention is as follows Figure 4As shown, the clamp includes a base 1, a first clamping assembly and a second clamping assembly. A groove 7 is provided at the center of the base for introducing back shielding gas during welding. The width and depth of the groove 7 are 50 mm and 30 mm respectively. There are 8 groups of first clamping assemblies. The 8 groups of first clamping assemblies are symmetrically arranged in pairs with the groove 7 as the center. There are 4 groups of first clamping assemblies on each side. The first clamping assembly includes an L-shaped bracket 2 and a first bolt. The first bolt includes a small bolt 5 and a large bolt 6. The diameter of the small bolt 5 is smaller than the diameter of the large bolt 6. When fixing, the small bolt 5 is first used to pre-tighten the plate to be welded, and then the large bolt 6 is used to tighten it, which can prevent the workpiece from deviating when the large bolt is tightened directly. The bottom of one end of the L-shaped bracket 2 is connected to the base 1, and the other end of the L-shaped bracket 2 is parallel to the upper surface of the base 1. The other end of the L-shaped bracket 2 is provided with a first bolt hole. The first bolt hole is also provided with two corresponding diameters, which match the diameters of the small bolt 5 and the large bolt 6 respectively. The first bolt hole is perpendicular to the upper surface of the base 1. There are 6 groups of second clamping assemblies, which are symmetrically arranged in pairs with the groove 7 as the center, and 3 groups of second clamping assemblies on each side. A second clamping assembly is arranged between each two adjacent first clamping assemblies. The second clamping assembly includes a fixing block 3 and a second bolt 4. The fixing block 3 is connected to the base 1. The fixing block 3 is provided with a second bolt hole. The second bolt hole is parallel to the upper surface of the base 1 and perpendicular to the groove 7. The second bolt 4 is arranged in the second bolt hole. When the alloy plates to be welded are placed on the base, the joint seam of the alloy plates to be welded is located directly above the groove, and the shielding gas enters from the groove to protect the back of the weld seam of the alloy plates to be welded.

[0090] Example 1

[0091] The test plates to be welded in this embodiment are two 30 mm thick nickel-based alloy plates with a welding length of 500 mm. The nickel-based alloy grade is GH3535 and the composition is Ni-16Mo-7Cr-4Fe. For specific composition, refer to Table 1 below.

[0092] Table 1 Chemical composition of GH3535 alloy (%)

[0093]

[0094] In the above table, each ratio is a mass percentage.

[0095] The laser wire welding method of this embodiment comprises the following steps:

[0096] (1) Cut a blunt V-shaped groove on two 30 mm thick nickel-based alloy plates, referring to Figure 1 The double-sided angle of the groove is 8°, the single-sided angle (the angle between the surface to be welded of one of the nickel-based alloy plates and the vertical surface) is 4°, the groove depth is 28mm, the blunt edge thickness is 2mm, the width is 3mm, and the butt surface gap is <0.02mm;

[0097] Use sandpaper to grind the burrs produced by cutting, and use anhydrous ethanol to wipe the surface to be welded, and clean the fixture at the same time; butt the two processed nickel-based alloy plates together, with the groove facing up, and place them in the fixture for fixing to obtain the plate to be welded;

[0098] (2) Laser self-melting welding is used to weld the blunt edge of the V-shaped groove to obtain a preliminary weld plate, which specifically includes:

[0099] Set the front outlet of the protective gas device to a distance b = 2~3mm from the upper surface of the plate to be welded, and the side outlet of the protective gas device to a distance a = 5mm from the laser beam. Figure 3 As shown;

[0100] Set the running trajectory of the welding robot and set the welding parameters: laser power 1500W, welding speed 0.8m / min, defocus 0mm, Circle-type oscillating laser, oscillation frequency 50Hz, oscillation amplitude 0.6mm; introduce protective gas, argon gas in three directions, 70L / min for the front protective gas, 50L / min for the side protective gas, and 15L / min for the back protective gas; start welding;

[0101] After welding, clean the small spatter on the weld and wipe the weld and the side wall of the groove with anhydrous ethanol to obtain the preliminary weld plate.

[0102] (3) Use laser wire welding to fill the V-shaped groove of the preliminary weld plate until the V-shaped groove is filled, specifically including:

[0103] Set the running track of the welding robot, feed the wire in front, introduce the wire feeding gun at 45° to the plate and parallel to the welding direction, the dry extension is 13mm, the welding wire is 1.2mm ERNiMo-2, the welding wire is in direct contact with the surface of the wire to be filled, and the distance between the center of the welding wire and the center of the laser beam is 0.4mm;

[0104] Set welding parameters: laser power 4500W, wire feeding speed 4.5m / min, welding speed 0.39m / min, defocusing amount +10mm, Circle-type oscillating laser, oscillating frequency 350Hz, oscillating amplitude 1 / 2 of the bottom width of the weld to be filled; introduce shielding gas, front shielding gas flow rate 70L / min, side shielding gas flow rate 50L / min, back shielding gas flow rate 0L / min; for the height of the shielding gas device, when the remaining height of the groove is 10~30mm, the height of the shielding gas delivery device from the parent material is 2~3mm, and the distance from the laser beam is 5mm; when the remaining height of the groove is 0-10mm, the height of the shielding gas delivery device from the parent material is 4~5mm, and the distance from the laser beam is 5mm;

[0105] Start welding, the depth-to-width ratio of a single-layer weld is 0.6-0.7, and a total of 6 welds are required in this embodiment. After welding, wipe the weld and use anhydrous ethanol to clean the weld and the side wall of the groove;

[0106] Repeat the above laser wire welding process until the entire groove is filled.

[0107] (4) The weld obtained in step (3) is capped by laser wire welding. The welding wire feeding parameters and shielding gas parameters of this step are the same as those of step (3). Except for the laser power of 4800 W and the wire feeding speed of 4.8 m / min, the other welding parameters are the same as those of step (3);

[0108] Obtain the welded plate.

[0109] Figure 2 The above is a schematic diagram of the welding process of this embodiment, wherein: Figure 2 Figure (b) shows the blunt edge welding of the groove, Figure (c) shows the laser wire welding to fill the groove, and Figure (d) shows the cover welding.

[0110] Figure 5 The figure shows the relationship between the depth-to-width ratio of a single-layer weld and weld cracks in laser wire welding. In the figure, W is the weld width of a single-layer weld with filler wire, D is the weld depth of a single-layer weld with filler wire, F is the weld mark for no cracks (False), and T is the weld mark for cracks (Ture). It can be seen that when the depth-to-width ratio of a single-layer weld is 0.72~1.24, weld cracks will occur.

[0111] Example 2

[0112] The difference between this embodiment and embodiment 1 is that the laser power in step (3) of this embodiment is 4200 W, and the remaining steps and parameters are the same as those of embodiment 1. The depth-to-width ratio of the single-layer weld in this embodiment is 1.07.

[0113] Figure 6 This is the front weld morphology of the preliminary weld plate of Example 1. Figure 7 This is the back weld morphology of the preliminary welded plate of Example 1. Figure 8 This is a morphology image of the last weld of the filling welding in step (3) of Example 1. Fig. 9 The weld after the cover welding in step (4) of Example 1, Fig.10 This is a nondestructive testing result diagram of the weld after the cap welding of Example 1. Fig.11 This is a metallographic image of the overall weld after cover welding in Example 1.

[0114] Fig.12(a) is a morphology diagram of the 4th filled weld in Example 1, (b) is a nondestructive testing result diagram of the 4th filled weld in Example 1, and (c) is a metallographic diagram of the 4th filled weld in Example 1. Fig.13 (a) is a morphology diagram of the 4th filled weld in Example 2, (b) is a nondestructive testing result diagram of the 4th filled weld in Example 2, and (c) is a metallographic diagram of the filled weld in Example 2.

[0115] It can be seen that when the laser power is 4200W, no obvious cracks are found in the weld. However, a black equiaxed crystal structure appears in the center of the weld. After comparing it with the metallographic picture of the welding wire, it is found that it is actually an incompletely melted welding wire. This unmelted welding wire shrinks in the surrounding welding wire solution due to the solidification and crystallization of the surrounding solution. The unmelted welding wire cannot compensate for the shrinkage, resulting in shrinkage defects in the weld. The same equiaxed crystal welding wire structure can be obtained in the metallographic microscope, and continuous dot-shaped line defects can be obtained in ultrasonic and radiographic nondestructive testing. When the power reaches 4500W, such defects disappear in metallographic and nondestructive testing.

[0116] Comparative Example 1

[0117] The difference between this comparative example and Example 1 is that in this comparative example, the laser power of step (3) is 5800 W, and the remaining steps and parameters are the same as those of Example 1. The depth-to-width ratio of the single-layer weld in this comparative example is 1.09.

[0118] Fig.14 It can be seen that obvious cracks appear in the weld.

[0119] Example 3

[0120] The difference between this embodiment and embodiment 1 is that in step (3) of this embodiment, the oscillation frequency of the 1st to 5th welds of laser wire welding is 100 Hz, and the oscillation frequency of the 6th weld is 350 Hz. The remaining steps and parameters are the same as those in embodiment 1.

[0121] Fig.15 The morphology of the 5th layer weld is shown. Fig.16 This is the morphology of the 6th weld. It can be seen that there are a large number of pores in the 4th and 5th welds, but there are no pores in the 6th weld.

[0122] Example 4

[0123] The difference between this embodiment and embodiment 1 is that in step (3) of this embodiment, the front shielding gas flow rate is 100 L / min, and the remaining steps and parameters are the same as those in embodiment 1.

[0124] Fig.17The morphology of the overall weld after the cap welding of Example 4 is shown. It can be seen that there are many pores in the weld. When the front shielding gas flow rate is 70L / min, Fig.11 It can be seen that there are no pores in the weld.

[0125] Welding mechanical testing:

[0126] The room temperature mechanical properties, high temperature mechanical properties and lateral bending properties of the welded plates are tested. The room temperature mechanical properties test method refers to the test standard AWS B4.0:2016, the high temperature mechanical properties test method refers to the test standard ASTME21-20, and the lateral bending properties test method refers to the test standard ASTM A370-23.

[0127] (1) Room temperature mechanical properties

[0128] Three groups of parallel specimens were prepared from the welded plate prepared in Example 1, and the samples were numbered T-1, T-2 and T-3.

[0129] The results of room temperature welding mechanical test are as follows Fig.18 As shown in Table 2. It can be seen that the tensile yield strength of the welded joint reached more than 310MPa (qualified value 280MPa), the tensile strength reached 810MPa (qualified value 690MPa), the elongation after fracture reached more than 54%, the sample broke at both the weld and the base material, and the strength reached the qualified requirements.

[0130] Table 2 Tensile properties at room temperature

[0131]

[0132] (2) High temperature mechanical properties

[0133] Six groups of parallel specimens were prepared from the welded plates prepared in Example 1. The samples were numbered T-4, T-5, T-6, T-7, T-8, and T-9. The test temperature of T-4, T-5, and T-6 was 650°C, and the test temperature of T-7, T-8, and T-9 was 700°C.

[0134] High temperature welding mechanical test results are as follows Fig.19As shown in Figure and Table 3. It can be seen that at 650℃, the tensile yield strength of the welded joint reached more than 213MPa (qualified value 185MPa), the tensile strength reached 570MPa (qualified value 479MPa), and the elongation after fracture reached more than 31.5%. The sample broke in the weld area. The strength met the qualified requirements; at 700℃, the tensile yield strength of the welded joint reached more than 206MPa (qualified value 181MPa), the tensile strength reached more than 528MPa (qualified value 433MPa), and the elongation after fracture reached more than 33%. The sample broke in the weld and parent material area. The strength met the qualified requirements.

[0135] Table 3 High temperature tensile properties

[0136]

[0137] (3) Bending test

[0138] Four groups of parallel samples were prepared from the welded plates prepared in Example 1, and the samples were numbered ZB-1, ZB-2, ZB-3, and ZB-4.

[0139] Table 4 Side bending performance

[0140]

[0141] The results of the lateral bending test are as follows Fig. 20 After the four parallel bending specimens were bent 180° sideways, the welds were inspected and no cracks were found, indicating that the test results were qualified.

Claims

1. A method for laser welding of nickel-based alloy plates with wire filling, characterized in that: It includes the following steps: (1) butting the surfaces to be welded of the first nickel-based alloy plate and the second nickel-based alloy plate and fixing them to obtain plates to be welded; A V-shaped groove is provided at the butt joint surface of the first nickel-based alloy plate and the second nickel-based alloy plate, and the bilateral angle of the V-shaped groove is 8-10°; (2) welding the blunt edge of the V-shaped groove to obtain a preliminary weld plate; (3) Under protective gas, the V-shaped groove of the preliminary welding plate is filled by laser wire welding until the V-shaped groove is filled; the welding parameters of the laser wire welding are: laser power is 4000~5000W, wire feeding speed is 4~5m / min, oscillating laser is used, and the oscillation frequency of the laser is 250~350Hz.

2. The laser wire welding method for nickel-based alloy plates according to claim 1, characterized in that: In step (3), the welding parameters of the laser wire welding satisfy one or more of the following conditions: ① The laser power is 4200~4800W; ②The wire feeding speed is 4.4~4.8m / min; ③ The laser power and the wire feeding speed meet the following conditions: for every 0.1 m / min increase in wire feeding speed, the laser power increases by 100 W; ④The swing amplitude of the laser is 1 / 2 of the bottom width of the weld to be filled; ⑤ The shape of the oscillating laser is a circle type; ⑥ The welding speed of the laser wire welding is 0.36~0.45m / min; and ⑦ the defocus amount in laser wire welding is +5~+10mm.

3. The laser wire welding method for nickel-based alloy plates according to claim 1, characterized in that: In step (3), the welding parameters of the laser wire welding satisfy one or more of the following conditions: ① The wire feeding method of welding wire is front wire feeding; ② The angle between the welding wire and the preliminary welding plate is 40~45°; ③The dry extension length of the welding wire is 13~15mm; ④The diameter of the welding wire is 1.1~1.2mm; ⑤The distance between the center of the welding wire and the center of the laser beam is 0~0.4mm; ⑥ The protective gas includes front protective gas and side protective gas, the flow rate of the front protective gas is 60~70L / min, and the flow rate of the side protective gas is 50~60L / min; and ⑦ a shielding gas delivery device is arranged above the preliminary welding plate, a front shielding gas outlet is arranged at the bottom of the shielding gas delivery device, and a side shielding gas outlet is arranged at the side of the shielding gas delivery device; when the remaining height of the groove is greater than 10 mm, the height of the front shielding gas outlet of the shielding gas delivery device from the upper surface of the preliminary welding plate is 2 to 3 mm, and the side shielding gas outlet is 3 to 5 mm away from the laser beam; when the remaining height of the groove is 0 to 10 mm, the height of the front shielding gas outlet of the shielding gas delivery device from the preliminary welding plate is 4 to 5 mm, and the side shielding gas outlet is 3 to 5 mm away from the laser beam.

4. The laser wire welding method for nickel-based alloy plates according to claim 1, characterized in that: The welding parameters of the laser wire-filling welding are: laser power 4500W, wire feeding speed 4.5m / min, welding speed 0.39m / min, defocusing amount +10mm, using Circle type oscillating laser, oscillating frequency 350Hz, oscillating amplitude 1 / 2 of the bottom width of the current weld to be filled; The protective gas includes front protective gas and side protective gas, and the flow rate of the front protective gas is 60-70 L / min; The flow rate of the side protection gas is 50-60 L / min.

5. The laser wire welding method for nickel-based alloy plates according to claim 1, characterized in that: In step (1), the nickel-based alloy plate laser wire welding method meets one or more of the following conditions: ① The bilateral angle of the V-shaped groove is 8°; ② The V-shaped groove is a blunt-edged V-shaped groove; the thickness of the blunt edge of the blunt-edged V-shaped groove is 2-4 mm; the width of the blunt edge of the blunt-edged V-shaped groove is 3-4 mm; the gap between the butt surfaces of the blunt edge of the blunt-edged V-shaped groove is <0.02 mm; ③The thickness of the first nickel-based alloy plate is 10-50 mm; ④The thickness of the second nickel-based alloy plate is 10-50 mm; ⑤ 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; and ⑥ 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.

6. The laser wire welding method for nickel-based alloy plates according to claim 1, characterized in that: In step (1), a clamp is used to butt the surfaces to be welded of the two first nickel-based alloy plates and the second nickel-based alloy plates; the clamp comprises a base, a plurality of first clamping components and a plurality of second clamping components, and a groove is provided at the center of the base; the plurality of first clamping components are symmetrically arranged in pairs with the groove as the center, and the plurality of second clamping components are symmetrically arranged in pairs with the groove as the center.

7. The laser wire welding method for nickel-based alloy plates according to claim 1, characterized in that: In step (2), the method for welding the blunt edge of the V-shaped groove comprises: welding the blunt edge of the V-shaped groove by laser autogenous welding under a protective gas; The welding parameters of the laser self-melting welding are: laser power of 1500-2000 W, welding speed of 0.6-1 m / min, defocus of -5-0 mm, swing laser, swing frequency of 50-200 Hz, swing amplitude of 0.6-1 mm, and the swing shape of the swing laser is circle type; The protective gas includes front protective gas, side protective gas and back protective gas; the flow rate of the front protective gas is 50~70L / min; the flow rate of the side protective gas is 50~80L / min, and the flow rate of the back protective gas is 15~20L / min.

8. The laser wire welding method for nickel-based alloy plates according to claim 1 or 7, characterized in that: In step (2), the method for welding the blunt edge of the V-shaped groove comprises: welding the blunt edge of the V-shaped groove by laser self-melting welding under a protective gas; the welding parameters of the laser self-melting welding are: laser power of 1500W, welding speed of 0.8m / min, defocus of 0mm, circle-type oscillating laser, oscillation frequency of 50Hz, oscillation amplitude of 0.6mm; the protective gas comprises front protective gas, side protective gas and back protective gas, the flow rate of the front protective gas is 50~70L / min, the flow rate of the side protective gas is 50~80L / min, and the flow rate of the back protective gas is 15~20L / min.

9. The laser wire welding method for nickel-based alloy plates according to claim 1, characterized in that: In step (3), after filling the V-shaped groove, the method further includes the step of performing cap welding on the laser wire-filled weld. The cap welding adopts laser wire-filled cap welding, and the laser power of the laser wire-filled cap welding is the same as the laser power of the laser wire-filled welding in step (3) or increases the laser power of the laser wire-filled welding in step (3) by 100 to 200 W, and the remaining process parameters are the same as the process parameters of the laser wire-filled welding in step (3); The parameters of the laser wire-filling cap welding include: front wire feeding, the wire feeding gun is introduced at 45° to the plate and parallel to the welding direction, the dry extension is 13 mm, the welding wire is 1.2 mm ERNiMo-2, the welding wire is directly in contact with the surface of the wire to be filled, and the distance between the center of the welding wire and the center of the laser beam is 0.4 mm; the laser power is 4500 W, the wire feeding speed is 4.5 m / min, the welding speed is 0.39 m / min, the defocus amount is +10 mm, a Circle-type oscillating laser is used, the oscillation frequency is 350 Hz, and the oscillation amplitude is 1 / 2 of the bottom width of the current weld to be filled; the front shielding gas and the side shielding gas are introduced, the flow rate of the front shielding gas is 70 L / min, the flow rate of the side shielding gas is 50 L / min, the height of the front shielding gas outlet of the shielding gas conveying device from the preliminary welding plate is 4-5 mm, and the distance of the side shielding gas outlet from the laser beam is 3-5 mm.

10. A nickel-based alloy plate obtained by the laser wire-filling welding method for nickel-based alloy plates according to any one of claims 1 to 9.

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