High-toughness nickel-based welding wire, preparation method and groove form

Abstract

The invention provides a high-toughness nickel-based welding wire, a preparation method and a groove form, and belongs to the technical field of metal materials. The high-toughness nickel-based welding wire comprises powder and a welding skin, and the powder comprises 22.0%-25.0% of Fe, 25.0%-30.0% of Cr, 10%-15% of Co, 1.0%-2.0% of Nb, 3.0%-5.0% of Al, 5.0%-7.0% of V, 5.0%-7.0% of W, 3%-5% of Mo, 0.5%-1.0% of B, 0.5%-1.0% of Zr, 0.4%-0.8% of CeO2, Y2O3, La2O3 and the balance Ni. And the welding skin is an Inconel 625 nickel strip. Optionally, the particle size of the medicine powder is 100 to 200 meshes. The solid solution strengthening effect is achieved by designing a weld joint alloy system with solid solution strengthening as a main part and precipitation strengthening as an auxiliary part, wherein the weld joint alloy system comprises various alloy elements such as Cr, Co, Mo, Nb, V and W; al is added to form a certain amount of gamma'strengthening phase, and B, Zr and rare earth oxide are added to remarkably improve the grain boundary bonding strength, so that a finally formed welding seam is excellent in obdurability.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the technical field of metal materials, and particularly relates to a high-toughness nickel-based welding wire, a preparation method and a groove form. BACKGROUND

[0002] GH2070P is a new type of high-temperature alloy material independently developed by China for the demand of 650 DEG C high-efficiency ultra-supercritical unit. The material significantly improves the high-temperature strength of the alloy through the reaction of Ti, Al and Ni to form gamma prime phase in the aging process, and meets the service requirements of the unit at 650 DEG C. During the construction of the unit, welding connection cannot be avoided. Due to the high strength of the material, if an equal strength matching welding wire is used for welding, since the weld is formed in a non-equilibrium solidification process, the strength of the weld is inevitably higher than that of the base material. It is found that the early use of solid solution strengthened 617 welding wire (ERNiCrCoMo-1) for welding shows that although the 617 welding wire is a solid solution strengthened welding material, due to the reasons of the base material fusion ratio and the characteristics of the non-equilibrium solidification of welding, the strength of the weld is high and the toughness is poor. Especially for the welded joints that will undergo large deformation during service, the high strength of the joint will not be conducive to deformation and is prone to brittle fracture. At the same time, the strength of the base material is high through aging strengthening, but the heat-affected zone next to the fusion line during welding will undergo solid solution and tempering, resulting in a weak area in the heat-affected zone, which is called a crack propagation channel during tensile and bending.

[0003] In view of the composition and performance characteristics of GH2070P material, the present disclosure develops a high-toughness welding material to meet the service requirements at high temperature. SUMMARY

[0004] The present disclosure aims to at least solve one of the problems in the prior art that the plastic deformation capacity of GH2070P joints is poor, and provides a high-toughness nickel-based welding wire, a preparation method and a groove form.

[0005] In one aspect of the present disclosure, a high-toughness nickel-based welding wire is provided, which comprises: The medicine powder comprises 22.0-25.0% of Fe, 25.0-30.0% of Cr, 10-15% of Co, 1.0-2.0% of Nb, 3.0-5.0% of Al, 5.0-7.0% of V, 5.0-7.0% of W, 3-5% of Mo, 0.5-1.0% of B, 0.5-1.0% of Zr, 0.4-0.8% of CeO2, Y2O3 and La2O3, and the balance of Ni. The welding sheath is an Inconel 625 nickel strip.

[0006] Optionally, the particle size of the drug powder is 100-200 mesh.

[0007] Optionally, the thickness of the Inconel 625 nickel strip is 0.3-0.5 mm, and the width is 6-8 mm.

[0008] Optionally, the filling rate of the drug powder is 18-20%.

[0009] Another aspect of the present disclosure provides a method for preparing the high-toughness nickel-based welding wire described above, the method comprising: Fe is 22.0-25.0%, Cr is 25.0-30.0%, Co is 10-15%, Nb is 1.0-2.0%, Al is 3.0-5.0%, V is 5.0-7.0%, W is 5.0-7.0%, Mo is 3-5%, B is 0.5-1.0%, Zr is 0.5-1.0%, CeO2+Y2O3+La2O3 is 0.4-0.8%, and the rest is Ni, as a drug powder; The drug powder is heated in a vacuum heating furnace, and the dried drug powder is placed in a powder mixer for thorough mixing; The sheath is pretreated, and the mixed drug powder is wrapped in the welding strip of the sheath, and after drawing treatment, a high-toughness nickel-based welding wire is obtained.

[0010] Optionally, the temperature for heating the drug powder in the vacuum heating furnace is 230-260℃, and the holding time is 2-3h.

[0011] Optionally, the time for thoroughly mixing the dried drug powder in the powder mixer is 1-2h.

[0012] Optionally, the diameter of the high-toughness nickel-based welding wire is 1.0-1.2mm.

[0013] Another aspect of the present disclosure provides a groove form for high-toughness nickel-based welding wire, which applies the high-toughness nickel-based welding wire described above to GH2070P base material welding, the thickness of the GH2070P base material is 20-60mm, a two-stage stepped groove is opened, the bottom U-shaped groove angle is 10-15°, the passivation thickness is 1.0-1.5mm, and the group-to-group gap is 0.8-1.5mm; the step height of the middle stepped groove is 3-5mm, the width is 2-3mm, and the groove angle is 6-10°; the width of the upper step is 2-3mm, the height is 2-3mm, and the groove angle is 5-8°.

[0014] This disclosure discloses a high-toughness nickel-based welding wire, its preparation method, and its beveling configuration. The high-toughness nickel-based welding wire comprises: a flux powder and a welding layer, wherein the flux powder comprises 22.0-25.0% Fe, 25.0-30.0% Cr, 10-15% Co, 1.0-2.0% Nb, 3.0-5.0% Al, 5.0-7.0% V, 5.0-7.0% W, 3-5% Mo, 0.5-1.0% B, 0.5-1.0% Zr, 0.4-0.8% CeO2, Y2O3, and La2O3, with the balance being Ni; the welding layer is Inconel 625 nickel strip. This disclosure utilizes a weld alloy system designed with solid solution strengthening as the primary method and precipitation strengthening as a secondary method. The system incorporates multiple alloying elements such as Cr, Co, Mo, Nb, V, and W to achieve solid solution strengthening. Al is added to form a certain amount of γ' strengthening phase. The addition of B, Zr, and rare earth oxides significantly improves the grain boundary bonding strength, resulting in a weld with excellent strength and toughness. Attached Figure Description

[0015] Figure 1 A flowchart illustrating the preparation method of high-toughness nickel-based welding wire according to a specific embodiment of this disclosure; Figure 2 The stepped bevel dimensions of the base material disclosed herein; Figure 3 The metallographic structure of the butt weld prepared in Example 2 of this disclosure; Figure 4 The butt joint prepared in Embodiment 2 of this disclosure has a fracture morphology after a room temperature tensile test. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain this disclosure and represent a part of the embodiments of this disclosure, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the protection scope of this disclosure.

[0017] In one aspect of this disclosure, a high-toughness nickel-based welding wire is provided, comprising: a flux powder and a welding layer, wherein the flux powder comprises 22.0-25.0% Fe, 25.0-30.0% Cr, 10-15% Co, 1.0-2.0% Nb, 3.0-5.0% Al, 5.0-7.0% V, 5.0-7.0% W, 3-5% Mo, 0.5-1.0% B, 0.5-1.0% Zr, 0.4-0.8% CeO2, Y2O3 and La2O3, with the balance being Ni, and the sum of the mass percentages of the above components being 100%; the welding layer is Inconel 625 nickel strip.

[0018] In some preferred embodiments, the purity of each of the above raw material component alloy powders is ≥99.9%, and the particle size of the powder is 100-200 mesh.

[0019] In some preferred embodiments, the Inconel 625 nickel strip has a thickness of 0.3-0.5 mm and a width of 6-8 mm. This weld strip serves as the outer coating material; the weld skin melts first during welding to form a protective layer, preventing the flux powder from being directly exposed to air and avoiding oxidation and impurity intrusion. Simultaneously, the Inconel 625 nickel strip itself contains elements such as Ni, Cr, and Mo, which work synergistically with the components in the flux powder to form the matrix of the weld metal. The Ni matrix provided by the weld skin possesses excellent ductility and toughness, while the strengthening elements in the flux powder (such as V, W, and Mo) enhance strength through solid solution and precipitation strengthening. The combination of these two elements achieves the "high strength and high toughness" characteristics of the weld. Furthermore, the melting of the weld skin provides the basic nickel-based composition, while the flux powder supplements other alloying elements, ensuring that the chemical composition of the weld meets design requirements. Elements such as Cr, Co, and Mo in the flux powder enhance strength through solid solution strengthening; Al and Nb promote the formation of the γ' phase to enhance high-temperature performance; B, Zr, and rare earth oxides (CeO2+Y2O3+La2O3) improve grain boundary bonding and increase toughness. The coating of the solder layer allows these elements to be released uniformly during the welding process, avoiding local component segregation.

[0020] In some preferred embodiments, the powder filling rate is 18-20%, optimizing the alloy ratio of the deposited metal and avoiding excessive or insufficient powder from affecting performance.

[0021] The welding wire designed in this embodiment has the following main alloy components and their functions: (1) The main alloying element of the welding wire cladding metal is Ni: Ni-based alloys have an fcc structure and good plasticity and toughness; Ni-based alloys have strong high-temperature oxidation resistance, which meets the service requirements of materials at high temperatures; Ni-based alloys have good high-temperature strength, and even if the temperature rises to above 500℃, the strength will not decrease significantly, ensuring service safety. Therefore, the welding wire alloy system is designed with Ni as the base material to meet the basic service requirements of the materials.

[0022] (2) The welding wire cladding metal contains a certain amount of Fe element: The addition of Fe element has two main functions. Fe itself is the main alloying element of the base material GH2070P. Adding a certain amount of Fe to the welding wire can ensure good welding performance between the welding wire and the base material. As can be seen from the Fe-Ni binary phase diagram, the two can be infinitely dissolved in solid solution. Therefore, the addition of Fe can be dissolved in the Ni matrix and play a role in solid solution strengthening. In addition, the price of Fe is relatively lower than that of Ni. Using a portion of Fe to add can reduce the production cost of the welding wire.

[0023] (3) The welding wire cladding metal contains a certain amount of Cr: The addition of Cr to the Ni matrix has two main functions. On the one hand, it acts as a solid solution strengthening element, improving the strength and toughness of the Ni matrix; on the other hand, Cr can improve the Ni matrix's resistance to high-temperature oxides. Ni itself has poor resistance to high-temperature oxidation compared to Cr. Cr can significantly improve the high-temperature performance of Ni-based alloys by forming a dense Cr2O3 protective layer, thereby ensuring its service requirements at high temperatures. However, excessive Cr will form a brittle phase with Fe, and excessive Cr will also lead to the formation of Cr-based solid solutions in the weld, which will reduce the weld's plasticity. Therefore, the Cr content should be controlled below its solid solubility in Ni.

[0024] (4) The welding wire cladding metal contains a certain amount of Co: When Co is added to the Ni matrix, it first forms a solid solution, causing lattice distortion, hindering dislocation movement, and strengthening the Ni matrix. In addition, Co can reduce the solubility of Al in the Ni matrix, thereby increasing the amount of γ' phase. Co can improve the hot working properties, plasticity, and impact toughness of Ni-based alloys. Therefore, in addition to strengthening the Ni matrix, the addition of Co significantly improves the plasticity and toughness of Ni-based alloys, ensuring that the welded joint can undergo good plastic deformation and resist the impact of extreme working conditions.

[0025] (5) The welding wire cladding metal contains a certain amount of Nb: Nb also has three functions in the Ni matrix. Some Nb is dissolved in the Ni matrix, which improves the strength and toughness of the Ni matrix through solid solution strengthening. Some Nb reacts with Ni to form the Ni3Nb intermetallic phase, which plays a precipitation strengthening role. In addition, the addition of Nb can promote the increase of the number, size and order of the γ' phase, and enhance the strengthening effect of the γ' phase.

[0026] (6) The welding wire cladding metal contains a certain amount of Al: The addition of Al to Ni-based welding materials is mainly to strengthen the Ni matrix by forming a γ'-Ni3Al strengthening phase. The amount of Al added should be strictly controlled. On the one hand, too much γ' strengthening phase will lead to poor toughness of the matrix, and on the other hand, too much Al will deteriorate the welding process performance of the welding wire.

[0027] (7) The welding wire cladding metal contains a certain amount of V element: Adding V to the Ni matrix can improve the strength and toughness of the Ni matrix through solid solution strengthening. On the other hand, V is a strong carbide forming element and can preferentially react with C to generate VC, pinning dislocations and grain boundaries, and enhancing the high-temperature strength of the material. (8) The welding wire cladding metal contains a certain amount of Mo and W elements: Adding Mo and W to the Ni matrix can significantly improve the strength of the Ni matrix due to solid solution strengthening, slow down the high-temperature diffusion rate of Al and Cr, strengthen the atomic bonding force in the solid solution, and slow down the softening rate. The effect of Mo is more significant than that of W. The addition of both can synergistically improve the overall performance of Ni-based alloys.

[0028] (9) The welding wire cladding metal contains a certain amount of B and Zr elements: After being added to Ni-based materials, B and Zr mainly exist on grain boundaries, improving grain boundary morphology, inhibiting the aggregation of coarse M23C6 carbides at grain boundaries, and delaying the occurrence of grain boundary cracks. In addition, B and Zr can also improve the creep resistance of materials and significantly improve notch sensitivity, thereby improving the plasticity and toughness of Ni-based alloys. The synergistic effect of adding both B and Zr on improving the Ni matrix is ​​more significant than that of adding a single element.

[0029] (10) The welding wire contains composite rare earth oxides CeO2+Y2O3+La2O3: The addition of rare earth oxides can improve the grain boundary state of the Ni matrix, increase grain boundary strength, improve the processing performance of the alloy, and improve creep resistance. The composite addition of rare earth oxides avoids the problem of single effect caused by the addition of a single rare earth oxide, and can synergistically improve the high-temperature performance of Ni-based alloys. In addition, the addition of rare earth elements to the welding wire makes the arc combustion more stable and the welding processability better.

[0030] As shown in Figure 1, another aspect of this disclosure provides a method S100 for preparing a high-toughness nickel-based welding wire, specifically including the following steps S110~S130: S110, weigh out the following components by mass percentage: Fe 22.0~25.0%, Cr 25.0~30.0%, Co 10~15%, Nb 1.0~2.0%, Al 3.0~5.0%, V 5.0~7.0%, W 5.0~7.0%, Mo 3~5%, B 0.5~1.0%, Zr 0.5~1.0%, CeO2+Y2O3+La2O3 0.4~0.8%, with the remainder being Ni. The sum of the mass percentages of the above components is 100%. Use the above-weighed components as the pharmaceutical powder.

[0031] S120. Place the weighed medicine powder from step 1 into a vacuum heating furnace and heat it at a temperature of 230~260℃ for 2~3 hours to remove the water of crystallization from the medicine powder. Place the dried medicine powder into a powder mixer for thorough mixing for 1~2 hours.

[0032] S130. The weld skin is pretreated, and the mixed powder is wrapped inside the weld strip of the weld skin. After drawing, a high-toughness nickel-based welding wire is obtained.

[0033] Specifically, alcohol is used to remove the grease from the surface of the Inconel 625 strip, and the flux powder prepared in step 2 is wrapped inside the Inconel 625 strip using a flux-cored wire drawing device. The diameter of the first drawing die is 2.6 mm. After the first drawing process is completed, the die diameter is reduced sequentially to finally obtain flux-cored wire with a diameter of 1.0~1.2 mm.

[0034] Of course, it should be understood that after the flux-cored welding wire is drawn, it still needs to be wound onto the welding wire spool by a wire winding machine, and finally sealed in a flux-cored welding wire vacuum packaging bag for later use.

[0035] In the preparation process of this embodiment, the powder components (Fe, Cr, Co, Nb, Al, V, W, Mo, etc.) achieve a balance between high strength and high toughness through the synergistic effects of solid solution strengthening, precipitation strengthening (γ' phase), and grain boundary strengthening (B, Zr, and rare earth oxides). Secondly, vacuum heating is used to thoroughly remove the water of crystallization from the powder, avoiding porosity or hydrogen embrittlement during welding, ensuring uniform distribution of alloying elements, reducing component segregation, and improving the consistency of the weld microstructure. Furthermore, multi-pass drawing gradually reduces the wire diameter, preventing uneven powder distribution or weld skin cracking, ensuring consistent wire diameter, and improving the stability of the welding process.

[0036] In another aspect of this disclosure, a bevel configuration for welding with a high-toughness nickel-based welding wire is proposed. The high-toughness nickel-based welding wire described above is applied to the welding of GH2070P base metal. During the welding process, the welding wire of this embodiment is adapted to the bevel configuration of the base metal as follows: Figure 2 As shown, the thickness of the GH2070P base material is 20~60mm, with a two-stage stepped bevel. The bottom U-shaped bevel angle is 10~15°, the passivation thickness is 1.0~1.5mm, and the assembly gap is 0.8~1.5mm. The step height of the middle stepped bevel is 3~5mm, the width is 2~3mm, and the bevel angle is 6~10°. The width of the top step is 2~3mm, the height is 2~3mm, and the bevel angle is 5~8°.

[0037] It should be understood that the welding wire composition disclosed herein is mainly designed for GH2070P base metal, which is an age-hardening nickel-based superalloy. The high-temperature strength is improved by the formation of γ' phase by Ti, Al and Ni. However, during welding, the heat-affected zone is prone to forming a weak zone due to solid solution and tempering, leading to the risk of crack propagation. Based on this, the welding wire of this embodiment uses Inconel 625 nickel strip (Ni-Cr-Mo) as the welding skin. The flux contains elements such as Fe, Cr, and Co, which have high compatibility with the Ni matrix of the base metal, avoiding interface problems in welding dissimilar materials. In addition, 22-25% Fe is added to the welding wire to match the main components of the base metal, reduce the composition gradient in the fusion zone, and reduce welding stress. At the same time, the cost is reduced through Fe-Ni solid solution strengthening, and the solid solution strengthening elements such as Cr, Co, and Mo complement the age-hardening mechanism of the base metal, avoiding excessively high weld strength. The Cr, Al, and rare earth oxides (CeO2+Y2O3+La2O3) in the welding wire enhance its oxidation and creep resistance, matching the base material's 650℃ service requirements.

[0038] In this embodiment, the fusion line is twisted by designing the above-mentioned two-stage stepped bevel. The bottom U-shaped bevel (10~15°), the middle step (6~10°), and the upper step (5~8°) form a twisted fusion line, which disperses the weak areas of the heat-affected zone and avoids straight crack paths. The flux-cored wire filling rate (18~20%) and the stepped bevel design precisely control the base metal fusion ratio, avoiding compositional segregation and performance inhomogeneity caused by non-equilibrium solidification. In addition, the stepped bevel disperses welding heat, reduces the softening degree of the heat-affected zone, and, combined with the low heat input characteristics of the welding wire (suitable for TIG / MIG), reduces deformation and residual stress. The B and Zr in the welding wire purify the grain boundaries and inhibit the aggregation of M23C6 carbides. Combined with the twisted fusion line of the stepped bevel, crack propagation is doubly inhibited.

[0039] This embodiment, by designing a reasonable bevel shape and twisting the fusion line, ensures that the weak areas of the heat-affected zone are not on a straight line, thereby blocking the crack propagation path and avoiding brittle fracture accidents.

[0040] The following will further illustrate the high-toughness nickel-based welding wire and its preparation method with specific embodiments: Example 1 Step 1: Weigh out the following components by mass percentage: Fe 22.0%, Cr 25.0%, Co 10%, Nb 1.0%, Al 3.0%, V 5.0%, W 5.0%, Mo 3%, B 0.5%, Zr 0.5%, CeO2+Y2O3+La2O3 0.4%, with the remainder being Ni. The sum of the mass percentages of the above components is 100%.

[0041] Step 2: Place the weighed powder from Step 1 into a vacuum heating furnace and heat it at 230℃ for 2 hours to remove the water of crystallization from the powder; place the dried powder into a powder mixer for thorough mixing for 1 hour. Step 3: Use alcohol to remove the grease from the surface of the Inconel 625 strip, and use a flux-cored wire drawing device to wrap the flux powder prepared in step 2 inside the Inconel 625 strip. The diameter of the first drawing die is 2.6mm. Step 4: After the first drawing process is completed, the die hole diameter is reduced in sequence to finally obtain flux-cored welding wire with a diameter of 1.0~1.2mm.

[0042] Step 5: After the flux-cored welding wire is drawn, it is wound onto the welding wire spool by a wire winding machine and finally sealed in a flux-cored welding wire vacuum packaging bag for later use.

[0043] Using a high-toughness nickel-based welding wire prepared in Implementation Case 1, GH2070P base material was welded. The base material was processed with the following beveling: the GH2070P base material was 20mm thick, with a two-stage stepped beveling. The bottom U-shaped beveling angle was 10°, the passivation thickness was 1.0mm, and the assembly gap was 0.8mm. The middle stepped beveling had a step height of 3mm, a width of 2mm, and a beveling angle of 6°. The upper step had a width of 2mm, a height of 2mm, and a beveling angle of 5°.

[0044] The aforementioned bevel was welded using a hot-wire TIG welding machine. The welding current was 100A and the welding voltage was 12.3V. The resulting joint underwent non-destructive, metallographic, and mechanical property tests. The test results are as follows: (1) The weld of the above-mentioned welded test plate was subjected to penetrant testing in accordance with the NB / T 47013.5-2015 "Non-destructive testing of pressure equipment - Part 5: Penetrant testing" standard. The results showed that the quality level of the test was Class I qualified.

[0045] (2) Radiographic testing was performed on the above-mentioned heat-treated welded test plate in accordance with NB / T 47013.2 "Non-destructive testing of pressure equipment - Part 2: Radiographic testing". The results showed that the radiographic testing technology level was AB and the quality level was I qualified.

[0046] (3) A 10mm thick bending specimen was prepared according to NB / T 47014-2023 "Welding Procedure Qualification for Pressure Equipment" and a three-point bending test was conducted on the joint (indenter diameter 60mm, span 83mm). The test results showed that the joint did not crack after bending 180°.

[0047] (4) Full-thickness compact tensile specimens were prepared. The tensile results showed that the joint strength was 915 MPa, the fracture area was the weld, and the elongation after fracture was 33%; the tensile strength of the pure base material was 970 MPa, and the elongation after fracture was 25%. This indicates that the weld has excellent plasticity and toughness.

[0048] (5) Prepare microhardness test specimens for the joint. The test results show that the weld hardness is 230HV0.3, the heat-affected zone hardness is 200HV0.3, and the base metal hardness is 300HV0.3. Example 2 Step 1: Weigh out the following components by mass percentage: Fe 25.0%, Cr 30.0%, Co 15%, Nb 2.0%, Al 5.0%, V 7.0%, W 7.0%, Mo 5%, B 1.0%, Zr 1.0%, CeO2+Y2O3+La2O3 0.8%, with the remainder being Ni. The sum of the mass percentages of the above components is 100%.

[0049] Step 2: Place the weighed powder from Step 1 into a vacuum heating furnace and heat it at 260℃ for 2-3 hours to remove the water of crystallization from the powder; place the dried powder into a powder mixer for thorough mixing for 1-2 hours. Step 3: Use alcohol to remove the grease from the surface of the Inconel 625 strip, and use a flux-cored wire drawing device to wrap the flux powder prepared in step 2 inside the Inconel 625 strip. The diameter of the first drawing die is 2.6mm. Step 4: After the first drawing process is completed, the die hole diameter is reduced in sequence to finally obtain flux-cored welding wire with a diameter of 1.0~1.2mm.

[0050] Step 5: After the flux-cored welding wire is drawn, it is wound onto the welding wire spool by a wire winding machine and finally sealed in a flux-cored welding wire vacuum packaging bag for later use.

[0051] Using a high-toughness nickel-based welding wire prepared in Implementation Case 2, GH2070P base metal was welded. The base metal was processed with the following beveling: the GH2070P base metal was 60mm thick, with a two-stage stepped beveling. The bottom U-shaped beveling angle was 15°, the passivation thickness was 1.5mm, and the assembly gap was 1.5mm. The middle stepped beveling had a step height of 5mm, a width of 3mm, and a beveling angle of 10°. The upper step had a width of 3mm, a height of 3mm, and a beveling angle of 8°.

[0052] The above-mentioned bevel was welded using a hot-wire TIG welding machine. The welding current was 110A and the welding voltage was 13.3V. The resulting joint underwent non-destructive, metallographic, and mechanical property tests. The test results are as follows: (1) The weld of the above-mentioned welded test plate was subjected to penetrant testing in accordance with the NB / T 47013.5-2015 "Non-destructive testing of pressure equipment - Part 5: Penetrant testing" standard. The results showed that the quality level of the test was Class I qualified.

[0053] (2) Radiographic testing was performed on the above-mentioned heat-treated welded test plate in accordance with NB / T 47013.2 "Non-destructive testing of pressure equipment - Part 2: Radiographic testing". The results showed that the radiographic testing technology level was AB and the quality level was I qualified.

[0054] (3) A 10mm thick bending specimen was prepared according to NB / T 47014-2023 "Welding Procedure Qualification for Pressure Equipment" and a three-point bending test was conducted on the joint (indenter diameter 60mm, span 83mm). The test results showed that the joint did not crack after bending 180°.

[0055] (4) Full-thickness compact tensile specimens were prepared. The tensile results showed that the joint strength was 927 MPa, the fracture area was the weld, and the elongation after fracture was 32.3%; the tensile strength of the pure base material was 970 MPa, and the elongation after fracture was 25%. This indicates that the weld has excellent plasticity and toughness.

[0056] (5) Prepare microhardness test specimens for the joint. The test results show that the weld hardness is 235HV0.3, the heat-affected zone hardness is 210HV0.3, and the base metal hardness is 300HV0.3. Figure 3 The image shows the metallographic structure of the butt weld prepared using Example 2. As can be seen from the image, the weld and base metal are well bonded, with no cracks, porosity, or other defects observed. The image also shows the step morphology, indicating good fusion at the step and absence of unfused defects on the sidewalls of the weld.

[0057] Figure 4 The butt joint prepared using Example 2 was subjected to a room temperature tensile test, and the post-fracture morphology of the joint is shown in the figure. As can be seen from the figure, the fracture surface is dominated by a mixed fracture of quasi-cleavage and dimples.

[0058] Example 3 Step 1: Weigh out the following components by mass percentage: Fe 23.0%, Cr 26.0%, Co 11%, Nb 1.1%, Al 3.1%, V 5.1%, W 5.1%, Mo 3.1%, B 0.6%, Zr 0.6%, CeO2+Y2O3+La2O3 0.5%, with the remainder being Ni. The sum of the mass percentages of the above components is 100%.

[0059] Step 2: Place the powder weighed in Step 1 into a vacuum heating furnace and heat it at 240℃ for 2.1 hours to remove the water of crystallization from the powder; place the dried powder into a powder mixer for thorough mixing for 1.1 hours. Step 3: Use alcohol to remove the grease from the surface of the Inconel 625 strip, and use a flux-cored wire drawing device to wrap the flux powder prepared in step 2 inside the Inconel 625 strip. The diameter of the first drawing die is 2.6mm. Step 4: After the first drawing process is completed, the die hole diameter is reduced in sequence to finally obtain flux-cored welding wire with a diameter of 1.0~1.2mm.

[0060] Step 5: After the flux-cored welding wire is drawn, it is wound onto the welding wire spool by a wire winding machine and finally sealed in a flux-cored welding wire vacuum packaging bag for later use.

[0061] Using a high-toughness nickel-based welding wire prepared in Implementation Case 3, GH2070P base material was welded. The base material was processed with the following beveling: the GH2070P base material was 30mm thick, with a two-stage stepped beveling. The bottom U-shaped beveling angle was 11°, the passivation thickness was 1.1mm, and the assembly gap was 0.9mm. The middle stepped beveling had a step height of 3.1mm, a width of 2.1mm, and a beveling angle of 7°. The upper step had a width of 2.1mm, a height of 2.1mm, and a beveling angle of 6°.

[0062] The aforementioned bevel was welded using a hot-wire TIG welding machine. The welding current was 109A and the welding voltage was 12.4V. The resulting joint underwent non-destructive, metallographic, and mechanical property tests. The test results are as follows: (1) The weld of the above-mentioned welded test plate was subjected to penetrant testing in accordance with the NB / T 47013.5-2015 "Non-destructive testing of pressure equipment - Part 5: Penetrant testing" standard. The results showed that the quality level of the test was Class I qualified.

[0063] (2) Radiographic testing was performed on the above-mentioned heat-treated welded test plate in accordance with NB / T 47013.2 "Non-destructive testing of pressure equipment - Part 2: Radiographic testing". The results showed that the radiographic testing technology level was AB and the quality level was I qualified.

[0064] (3) A 10mm thick bending specimen was prepared according to NB / T 47014-2023 "Welding Procedure Qualification for Pressure Equipment" and a three-point bending test was conducted on the joint (indenter diameter 60mm, span 83mm). The test results showed that the joint did not crack after bending 180°.

[0065] (4) Full-thickness compact tensile specimens were prepared. The tensile results showed that the joint strength was 931 MPa, the fracture area was the weld, and the elongation after fracture was 31%; the tensile strength of the pure base material was 970 MPa, and the elongation after fracture was 25%. This indicates that the weld has excellent plasticity and toughness.

[0066] (5) Prepare microhardness test specimens for joints. The test results show that the weld hardness is 237HV0.3, the heat-affected zone hardness is 201HV0.3, and the base material hardness is 300HV0.3.

[0067] Example 4 Step 1: Weigh out the following components by mass percentage: Fe 24.0%, Cr 27.0%, Co 12%, Nb 1.3%, Al 3.5%, V 5.5%, W 5.5%, Mo 3.5%, B 0.7%, Zr 0.7%, CeO2+Y2O3+La2O3 0.6%, with the remainder being Ni. The sum of the mass percentages of the above components is 100%.

[0068] Step 2: Place the weighed powder from Step 1 into a vacuum heating furnace and heat it at 240℃ for 2.3 hours to remove the water of crystallization from the powder; place the dried powder into a powder mixer for thorough mixing for 1.2 hours. Step 3: Use alcohol to remove the grease from the surface of the Inconel 625 strip, and use a flux-cored wire drawing device to wrap the flux powder prepared in step 2 inside the Inconel 625 strip. The diameter of the first drawing die is 2.6mm. Step 4: After the first drawing process is completed, the die hole diameter is reduced in sequence to finally obtain flux-cored welding wire with a diameter of 1.0~1.2mm.

[0069] Step 5: After the flux-cored welding wire is drawn, it is wound onto the welding wire spool by a wire winding machine and finally sealed in a flux-cored welding wire vacuum packaging bag for later use.

[0070] Using a high-toughness nickel-based welding wire prepared in Implementation Case 4, GH2070P base metal was welded. The base metal was processed with the following beveling: the GH2070P base metal thickness was 20~60mm, with a two-stage stepped beveling. The bottom U-shaped beveling angle was 12°, the passivation thickness was 1.2mm, and the assembly gap was 1.0mm. The middle stepped beveling had a step height of 4mm, a width of 2.5mm, and a beveling angle of 8°. The upper step had a width of 2.5mm, a height of 2.3mm, and a beveling angle of 7°.

[0071] The aforementioned bevel was welded using a hot-wire TIG welding machine. The welding current was 107A and the welding voltage was 12.9V. The resulting joint underwent non-destructive, metallographic, and mechanical property tests. The test results are as follows: (1) The weld of the above-mentioned welded test plate was subjected to penetrant testing in accordance with the NB / T 47013.5-2015 "Non-destructive testing of pressure equipment - Part 5: Penetrant testing" standard. The results showed that the quality level of the test was Class I qualified.

[0072] (2) Radiographic testing was performed on the above-mentioned heat-treated welded test plate in accordance with NB / T 47013.2 "Non-destructive testing of pressure equipment - Part 2: Radiographic testing". The results showed that the radiographic testing technology level was AB and the quality level was I qualified.

[0073] (3) A 10mm thick bending specimen was prepared according to NB / T 47014-2023 "Welding Procedure Qualification for Pressure Equipment" and a three-point bending test was conducted on the joint (indenter diameter 60mm, span 83mm). The test results showed that the joint did not crack after bending 180°.

[0074] (4) Full-thickness compact tensile specimens were prepared. The tensile results showed that the joint strength was 927 MPa, the fracture area was the weld, and the elongation after fracture was 31.8%; the tensile strength of the pure base material was 970 MPa, and the elongation after fracture was 25%. This indicates that the weld has excellent plasticity and toughness.

[0075] (5) Prepare microhardness test specimens for the joint. The test results show that the weld hardness is 233HV0.3, the heat-affected zone hardness is 201HV0.3, and the base metal hardness is 300HV0.3. Example 5 Step 1: Weigh out the following components by mass percentage: Fe 24.0%, Cr 27.0%, Co 13.0%, Nb 1.6%, Al 4.5%, V 6.6%, W 6.6%, Mo 4.2%, B 0.8%, Zr 0.8%, CeO2+Y2O3+La2O3 0.71%, with the remainder being Ni. The sum of the mass percentages of the above components is 100%.

[0076] Step 2: Place the weighed powder from Step 1 into a vacuum heating furnace and heat it at 255℃ for 2.7 hours to remove the water of crystallization from the powder; place the dried powder into a powder mixer for thorough mixing for 1.7 hours. Step 3: Use alcohol to remove the grease from the surface of the Inconel 625 strip, and use a flux-cored wire drawing device to wrap the flux powder prepared in step 2 inside the Inconel 625 strip. The diameter of the first drawing die is 2.6mm. Step 4: After the first drawing process is completed, the die hole diameter is reduced in sequence to finally obtain flux-cored welding wire with a diameter of 1.0~1.2mm.

[0077] Step 5: After the flux-cored welding wire is drawn, it is wound onto the welding wire spool by a wire winding machine and finally sealed in a flux-cored welding wire vacuum packaging bag for later use.

[0078] Using a high-toughness nickel-based welding wire prepared in Implementation Case 5, GH2070P base metal was welded. The base metal was processed with the following beveling: the GH2070P base metal was 50mm thick, with a two-stage stepped beveling. The bottom U-shaped beveling angle was 14°, the passivation thickness was 1.4mm, and the assembly gap was 1.4mm. The middle stepped beveling had a step height of 4.1mm, a width of 2.8mm, and a beveling angle of 9°. The upper step had a width of 2.8mm, a height of 2.8mm, and a beveling angle of 7.5°.

[0079] The above-mentioned bevel was welded using a hot-wire TIG welding machine. The welding current was 113A and the welding voltage was 12.0V. The resulting joint underwent non-destructive, metallographic, and mechanical property tests. The test results are as follows: (1) The weld of the above-mentioned welded test plate was subjected to penetrant testing in accordance with the NB / T 47013.5-2015 "Non-destructive testing of pressure equipment - Part 5: Penetrant testing" standard. The results showed that the quality level of the test was Class I qualified.

[0080] (2) Radiographic testing was performed on the above-mentioned heat-treated welded test plate in accordance with NB / T 47013.2 "Non-destructive testing of pressure equipment - Part 2: Radiographic testing". The results showed that the radiographic testing technology level was AB and the quality level was I qualified.

[0081] (3) A 10mm thick bending specimen was prepared according to NB / T 47014-2023 "Welding Procedure Qualification for Pressure Equipment" and a three-point bending test was conducted on the joint (indenter diameter 60mm, span 83mm). The test results showed that the joint did not crack after bending 180°.

[0082] (4) Full-thickness compact tensile specimens were prepared. The tensile results showed that the joint strength was 922 MPa, the fracture area was the weld, and the elongation after fracture was 32.7%; the tensile strength of the pure base material was 970 MPa, and the elongation after fracture was 25%. This indicates that the weld has excellent plasticity and toughness.

[0083] (5) Prepare microhardness test specimens for joints. The test results show that the weld hardness is 241HV0.3, the heat-affected zone hardness is 212HV0.3, and the base material hardness is 300HV0.3.

[0084] Example 6 Step 1: Weigh out the following components by mass percentage: Fe 24.9%, Cr 29.1%, Co 14.5%, Nb 1.95%, Al 4.95%, V 6.95%, W 6.95%, Mo 4.95%, B 0.95%, Zr 0.95%, CeO2+Y2O3+La2O3 0.75%, with the remainder being Ni. The sum of the mass percentages of the above components is 100%.

[0085] Step 2: Place the powder weighed in Step 1 into a vacuum heating furnace and heat it at 251℃ for 2.9 hours to remove the water of crystallization from the powder; place the dried powder into a powder mixer for thorough mixing for 1.9 hours. Step 3: Use alcohol to remove the grease from the surface of the Inconel 625 strip, and use a flux-cored wire drawing device to wrap the flux powder prepared in step 2 inside the Inconel 625 strip. The diameter of the first drawing die is 2.6mm. Step 4: After the first drawing process is completed, the die hole diameter is reduced in sequence to finally obtain flux-cored welding wire with a diameter of 1.0~1.2mm.

[0086] Step 5: After the flux-cored welding wire is drawn, it is wound onto the welding wire spool by a wire winding machine and finally sealed in a flux-cored welding wire vacuum packaging bag for later use.

[0087] Using a high-toughness nickel-based welding wire prepared in Implementation Case 6, GH2070P base metal was welded. The base metal was processed with the following beveling: the GH2070P base metal was 29mm thick, with a two-stage stepped beveling. The bottom U-shaped beveling angle was 14.5°, the passivation thickness was 1.42mm, and the assembly gap was 1.49mm. The middle stepped beveling had a step height of 4.9mm, a width of 2.9mm, and a beveling angle of 9.1°. The upper step had a width of 2.91mm, a height of 2.91mm, and a beveling angle of 7.9°.

[0088] The above-mentioned bevel was welded using a hot-wire TIG welding machine. The welding current was 111A and the welding voltage was 12.8V. The resulting joint underwent non-destructive, metallographic, and mechanical property tests. The test results are as follows: (1) The weld of the above-mentioned welded test plate was subjected to penetrant testing in accordance with the NB / T 47013.5-2015 "Non-destructive testing of pressure equipment - Part 5: Penetrant testing" standard. The results showed that the quality level of the test was Class I qualified.

[0089] (2) Radiographic testing was performed on the above-mentioned heat-treated welded test plate in accordance with NB / T 47013.2 "Non-destructive testing of pressure equipment - Part 2: Radiographic testing". The results showed that the radiographic testing technology level was AB and the quality level was I qualified.

[0090] (3) A 10mm thick bending specimen was prepared according to NB / T 47014-2023 "Welding Procedure Qualification for Pressure Equipment" and a three-point bending test was conducted on the joint (indenter diameter 60mm, span 83mm). The test results showed that the joint did not crack after bending 180°.

[0091] (4) Full-thickness compact tensile specimens were prepared. The tensile results showed that the joint strength was 918 MPa, the fracture area was the weld, and the elongation after fracture was 34.1%; the tensile strength of the pure base material was 970 MPa, and the elongation after fracture was 25%. This indicates that the weld has excellent plasticity and toughness.

[0092] (5) Prepare microhardness test specimens for joints. The test results show that the weld hardness is 219HV0.3, the heat-affected zone hardness is 198HV0.3, and the base metal hardness is 300HV0.3.

[0093] This disclosure presents a high-toughness nickel-based welding wire, its preparation method, and its bevel configuration, which have the following advantages compared to existing technologies: (1) When welding GH2070P high-temperature alloy with welding wire of this disclosure, the resulting joint has excellent plasticity and toughness. When a load is applied, the weld can release stress through a part of plastic deformation.

[0094] (2) This disclosure uses a weld alloy system with solid solution strengthening as the main component and precipitation strengthening as the auxiliary component: multiple alloying elements such as Cr, Co, Mo, Nb, V, and W are used to form solid solution strengthening effect; Al is added to form a certain amount of γ' strengthening phase; and the addition of B, Zr and rare earth oxides significantly improves the grain boundary bonding strength. The resulting weld has excellent strength and toughness.

[0095] (3) The double-step groove design of this invention causes the fusion line of the welded joint to be twisted, which makes the weak area of ​​the heat-affected zone of the joint fluctuate (not on the same line), thus preventing the crack propagation channel and avoiding the occurrence of brittle fracture accident.

[0096] (4) The welding wire preparation process disclosed herein is simple and can be used for welding with either TIG or MIG, making it highly applicable to engineering projects.

[0097] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A high-toughness nickel-based welding wire, characterized in that, The high-toughness nickel-based welding wire includes: It includes flux powder and solder coating, wherein the flux powder comprises 22.0~25.0% Fe, 25.0~30.0% Cr, 10~15% Co, 1.0~2.0% Nb, 3.0~5.0% Al, 5.0~7.0% V, 5.0~7.0% W, 3~5% Mo, 0.5~1.0% B, 0.5~1.0% Zr, 0.4~0.8% CeO2, Y2O3 and La2O3, with the balance being Ni; The solder sheet is Inconel 625 nickel strip.

2. The high-toughness nickel-based welding wire according to claim 1, characterized in that, The particle size of the powder is 100-200 mesh.

3. The high-toughness nickel-based welding wire according to claim 1, characterized in that, The Inconel 625 nickel strip has a thickness of 0.3-0.5 mm and a width of 6-8 mm.

4. The high-toughness nickel-based welding wire according to claim 1, characterized in that, The filling rate of the powder is 18-20%.

5. A method for preparing the high-toughness nickel-based welding wire as described in any one of claims 1 to 4, characterized in that, The method includes: Weigh out the following components by mass percentage: Fe 22.0~25.0%, Cr 25.0~30.0%, Co 10~15%, Nb 1.0~2.0%, Al 3.0~5.0%, V 5.0~7.0%, W 5.0~7.0%, Mo 3~5%, B 0.5~1.0%, Zr 0.5~1.0%, CeO2+Y2O3+La2O3 0.4~0.8%, with the remainder being Ni, as the pharmaceutical powder. The powder is heated in a vacuum furnace and then thoroughly mixed in a powder mixer. The welding skin is pretreated, and the mixed powder is wrapped inside the welding strip of the welding skin. After drawing, a high-toughness nickel-based welding wire is obtained.

6. The method according to claim 5, characterized in that, The powder is placed in a vacuum heating furnace and heated to a temperature of 230~260℃ for 2~3 hours.

7. The method according to claim 5, characterized in that, The dried medicinal powder is placed in a powder mixer and mixed thoroughly for 1-2 hours.

8. The method according to claim 5, characterized in that, The diameter of the high-toughness nickel-based welding wire is 1.0~1.2mm.

9. A bevel configuration for welding with high-toughness nickel-based welding wire as described in any one of claims 1-4, characterized in that, The high-toughness nickel-based welding wire is used in the welding of GH2070P base metal; wherein... The GH2070P base material has a thickness of 20~60mm, with a two-stage stepped bevel. The bottom U-shaped bevel angle is 10~15°, the passivation thickness is 1.0~1.5mm, and the assembly gap is 0.8~1.5mm. The middle stepped bevel has a step height of 3~5mm, a width of 2~3mm, and a bevel angle of 6~10°. The top step has a width of 2~3mm, a height of 2~3mm, and a bevel angle of 5~8°.

Images