Material and method for nickel-based alloy laser cladding and GTAW connection

Abstract

The invention discloses a nickel-based alloy material for laser cladding and GTAW connection. The nickel-based alloy material comprises a laser cladding material and a GTAW welding material, wherein the laser cladding material comprises the following components in percentage by mass: 20.0-30.0% of Ni powder, 20.0-30.0% of Co powder, 10.0-20.0% of Cr powder and the balance of Fe powder, and the sum of the mass percentages of the components is 100%; the GTAW welding material comprises a flux core and a welding skin, the flux core comprises, by mass, 30.0%-40.0% of Fe powder, 10.0%-20.0% of Co powder, 10.0%-20.0% of Ta powder, 3%-6% of Al powder, 3%-6% of Ti powder and the balance Ni powder, and the sum of the mass percentages of the components is 100%. The invention further discloses a nickel-based alloy welding connection method, and the softening problem of the aging-state iron-nickel-based high-temperature alloy joint under the GTAW technology is solved.

Description

Technical Field

[0001] This invention belongs to the field of metal materials technology, specifically relating to materials for laser cladding + GTAW bonding of nickel-based alloys, and also to welding methods for nickel-based alloys. Background Technology

[0002] Nickel-based superalloys are widely used in the manufacture of core components in aerospace, energy, and chemical industries due to their excellent high-temperature strength, creep resistance, and corrosion resistance. These components are typically in forged form and undergo heat treatment to achieve age-hardening and optimal comprehensive mechanical properties. However, welding connections are often required during the manufacturing or repair of these components, posing a significant challenge to the age-hardened nickel-based superalloys.

[0003] Currently, GTAW (Tungsten Inert Gas Welding) is a commonly used method for welding such materials. However, the GTAW process has a relatively high heat input, and the welding heat cycle generated during the welding process causes the heat-affected zone (HAZ) of the forging base material to undergo a process of "over-aging" or dissolution and coarsening of precipitates. For the base material in an aged state, the strengthening effect originally achieved by fine precipitates (such as γ' and γ'' phases) is significantly weakened in the HAZ, resulting in a "softening" phenomenon in this area. The strength and hardness of this softened area are significantly lower than those of the base material and the weld metal, becoming the weakest link in the entire welded joint and severely restricting the performance and reliability of the joint under harsh conditions such as high temperature and high pressure.

[0004] To mitigate the softening problem in the heat-affected zone (HAZ), existing technologies typically employ methods such as reducing welding heat input or optimizing post-weld heat treatment. However, simply reducing the heat input of GTAW (Gas-Affected Welding) has limited effectiveness and may introduce new problems such as insufficient penetration and lack of fusion. Furthermore, improper control of the post-weld heat treatment process makes it difficult to accurately restore the microstructure and properties of the HAZ, and may even adversely affect other areas of the weld or base material. Laser cladding technology, as a high-energy beam processing method, features high energy density, low heat input, rapid cooling, and an extremely narrow HAZ. Theoretically, laser cladding can significantly reduce the thermal impact on aged base material. However, if used directly as a joining method, its penetration capability for thick forgings is limited, and the compatibility of the chemical composition of the cladding layer with the subsequent welding materials, as well as the overall joint performance control under their synergistic effect, remain pressing technical challenges.

[0005] Therefore, how to effectively overcome the softening defect in the heat-affected zone of GTAW welded joints of aged nickel-based superalloys, and develop a special welding material and matching preparation method that can be matched with the new composite welding process (laser cladding + GTAW) to achieve the coordination and improvement of the overall performance of the joint, has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] The first objective of this invention is to provide a material for connecting nickel-based alloys by laser cladding and GTAW, including laser cladding material and GTAW welding material, which solves the softening problem of aged iron-nickel-based superalloy joints under the GTAW process.

[0007] The second objective of this invention is to provide a welding method for nickel-based alloys, which ultimately achieves uniform and consistent performance of the welded joints of aged nickel-based superalloys and solves the softening problem of aged iron-nickel-based superalloy joints under the GTAW process.

[0008] The first technical solution adopted in this invention is a nickel-based alloy laser cladding + GTAW bonding material, including laser cladding material and GTAW welding material; The laser cladding material comprises the following components by mass percentage: 20.0-30.0% Ni powder, 20.0-30.0% Co powder, 10.0-20.0% Cr powder, and the remainder is Fe powder, with the sum of the mass percentages of the above components being 100%. GTAW welding material includes a flux core and a solder coating. The flux core comprises the following components by mass percentage: 30.0-40.0% Fe powder, 10.0-20.0% Co powder, 10.0-20.0% Ta powder, 3-6% Al powder, 3-6% Ti powder, and the remainder is Ni powder. The sum of the mass percentages of the above components is 100%.

[0009] The purity of each raw material powder constituting the laser cladding material is ≥99.9%; the purity of each raw material powder constituting the core in the GTAW welding material is ≥99.1%; the particle size of each raw material powder constituting the core in the GTAW welding material is 100 mesh to 200 mesh.

[0010] The invention is further characterized in that: In GTAW welding materials, the weld skin is Inconel 625 strip, with a thickness of 0.4mm and a width of 7mm.

[0011] The flux-cored filling rate of GTAW welding material is controlled at 20wt%~25wt%.

[0012] The specific steps for preparing laser cladding materials are as follows: Step 1: Weigh out Ni powder (20.0-30.0%), Co powder (20.0-30.0%), Cr powder (10.0-20.0%), and the remainder Fe powder according to their respective mass percentages. The sum of the mass percentages of the above components shall be 100%. Step 2: Mix the raw material powders weighed in Step 1 and then vacuum melt them, using a gas atomization method to produce powder; In step 2, a vacuum melting equipment is used, with N2 as the atomizing gas and an atomization pressure of 6 MPa to 8 MPa. During the atomization process, the superheat of the melt is maintained at 100°C to 150°C. Step 3: Perform particle size sieving on the atomized powder to ensure that the sieved powder is within a certain particle size range; In step 3, the particle size range of the sieved powder is 25μm~53μm, that is, 270 mesh~500 mesh; the flowability requirement of the sieved powder is 25s / 100g~40s / 100g. Step 4: Vacuum package the prepared powder for later use.

[0013] The preparation method of GTAW welding material, and the specific steps are as follows: Step 1: Weigh out the following components by mass percentage: 30.0-40.0% Fe powder, 10.0-20.0% Co powder, 10.0-20.0% Ta powder, 3-6% Al powder, 3-6% Ti powder, with the remainder being Ni powder. The sum of the mass percentages of the above components should be 100%. Step 2: Place the weighed powder from Step 1 into a vacuum heating furnace and heat it at a temperature of 200℃~260℃ for 1h~2h to remove the water of crystallization from the powder; place the dried powder into a powder mixer for thorough mixing for 1h~2h. Step 3: Use Inconel 625 strip as the solder coating; remove grease from the surface of the Inconel 625 strip with alcohol, and wrap the flux powder prepared in Step 2 inside the Inconel 625 strip using a flux-cored wire drawing device. The first drawing die has a diameter of 2.6 mm; in Step 3, the flux filling rate is controlled at 20wt%~25wt%. Step 4: After the first drawing process is completed, the die hole diameter is reduced one by one to finally obtain a flux-cored wire with a diameter of 1.2mm; 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.

[0014] The second technical solution adopted in this invention is a nickel-based alloy welding connection method, which uses the above-mentioned nickel-based alloy laser cladding + GTAW welding material for nickel-based alloy welding connection. The specific steps are as follows: Step 1: Make a U-shaped bevel at the welding joint of the two nickel-based alloy plates to be welded. The top edge of the U-shaped bevel is a step. Step 2: Perform laser cladding on the stepped surface at the top of the bevel opened in Step 1, selecting the laser cladding material mentioned above; Step 3: Perform butt welding at the bevel prepared in Step 1 using hot wire GTAW automatic welding process, and use the GTAW welding material mentioned above as the welding material. Step 4: Perform two post-weld heat treatments on the resulting joint.

[0015] The invention is further characterized in that: In step 1, the specific dimensional parameters of the U-shaped bevel are as follows: the angle on one side is 5°~8°, the blunt side dimension is 0.5mm~1.0mm; the width of the step at the top of the bevel is 15mm~20mm, and the step depth is 1mm~2mm. The bevel dimensions are as follows: Figure 2 As shown; In step 2, the laser power of laser cladding is 1kW~3kW, and the thickness of the cladding layer is greater than the step depth by 0.5mm~1.0mm; In step 3, the welding current is 130 A ~ 200 A, the thickness of each layer is controlled between 1 mm and 2.5 mm, and the interpass temperature is controlled between 20℃ and 50℃.

[0016] Step 4 is as follows: The first step is to rapidly heat the welded joint to 850℃~900℃ and hold it at that temperature for 4h~6h; the heating and cooling rates are both 100℃ / h~300℃ / h. The second step is to heat the above-mentioned joint to 800℃~830℃ and keep it at that temperature for 8h~12h; the heating rate and cooling rate are both 50℃ / h~100℃ / h.

[0017] The beneficial effects of this invention are: (1) The material of this invention is designed for the characteristic that aged nickel-based superalloys are mainly strengthened by the γ' phase. The main weld metal system of the GTAW is based on the Ni-Cr-Fe alloy system, combined with solid solution strengthening of Co, Fe, Ta, Mo and Nb elements and precipitation strengthening of Al and Ti elements, to ensure excellent performance matching of the weld joint. This solves the softening problem of aged iron-nickel-based superalloy joints under the GTAW process.

[0018] (2) The present invention addresses the problem of softening of aged nickel-based alloy joints after GTAW welding by developing a laser cladding + GTAW composite welding process, which ultimately achieves uniform and consistent performance of aged nickel-based high-temperature alloy joints after welding.

[0019] (3) The method of the present invention is designed for the material characteristics of nickel-based high-temperature alloy aging, and Ni-Co-Cr-Fe alloy powder is designed to achieve excellent connection with nickel-based aged base material through solid solution strengthening.

[0020] (4) The method of the present invention designs a step at the top of the traditional U-shaped groove for the preparation of the laser cladding layer; the step serves to twist the fusion line and reduce the welding heat input, thereby ensuring the strength matching between the weld and the base material.

[0021] (5) The method of the present invention is designed with a two-step post-weld heat treatment process for laser cladding + GTAW joint, thereby avoiding the formation of a softened area in the joint and ensuring the strength and toughness of the joint. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating steps 2 and 3 of the nickel-based alloy welding method of the present invention. Figure 2 This is a schematic diagram of the structure of the nickel-based alloy welding bevel used in this invention; Figure 3 The metallographic structure of the laser cladding layer prepared using Example 2; Figure 4 The metallographic structure of the GTAW weld prepared using Example 2. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0024] This invention provides materials for connecting nickel-based alloys using laser cladding and GTAW welding, including laser cladding materials and GTAW welding materials; The laser cladding material comprises the following components by mass percentage: 20.0-30.0% Ni powder, 20.0-30.0% Co powder, 10.0-20.0% Cr powder, and the remainder is Fe powder, with the sum of the mass percentages of the above components being 100%. GTAW welding material includes a flux core and a solder coating. The flux core comprises the following components by mass percentage: 30.0-40.0% Fe powder, 10.0-20.0% Co powder, 10.0-20.0% Ta powder, 3-6% Al powder, 3-6% Ti powder, and the remainder is Ni powder. The sum of the mass percentages of the above components is 100%.

[0025] The purity of each raw material powder constituting the laser cladding material is ≥99.9%; in the GTAW welding material, the purity of each raw material powder constituting the core is ≥99.1%. In GTAW welding materials, the particle size of each raw material powder that makes up the core is 100-200 mesh.

[0026] In GTAW welding materials, the weld skin is Inconel 625 strip, with a thickness of 0.4mm and a width of 7mm.

[0027] The flux-cored filling rate of GTAW welding material is controlled at 20wt%~25wt%.

[0028] The roles and functions of the main components in the nickel-based alloy laser cladding + GTAW bonding material of this invention are as follows: (1) The main elements of laser cladding materials are: Ni, Co, Cr, Fe 1) Ni element: The main alloying element of the nickel-based alloy to be welded is Ni, so the laser cladding material is mainly Ni, which is a composition matching.

[0029] 2) Co element: The strengthening mechanism of laser cladding materials is solid solution strengthening. Co element is dissolved in the γ-Ni matrix, which can significantly improve the strength of its nickel-based alloy. The laser cladding layer itself is prepared on the outside of the pipe, so adding Co element can also effectively suppress the oxidation notch problem at the fusion line of the GTAW weld joint caused by the inconsistency of high temperature resistance between the base material and the weld.

[0030] 3) Cr element: The introduction of Cr element is based on two considerations: First, it is dissolved in the γ-Ni matrix and achieves significant solid solution strengthening through the lattice distortion effect, thereby effectively improving the strength of the transition layer and making it match the performance of the base material; Second, Cr can preferentially form a dense and well-adhesive chromium oxide (Cr2O3) protective film on the surface under high temperature environment, which fundamentally enhances the high temperature oxidation resistance of the weld overlay alloy.

[0031] 4) Fe element: The introduction of Fe element mainly plays a dual role: First, it dissolves in the γ-Ni matrix, inducing lattice distortion and producing a significant solid solution strengthening effect, thereby directly improving the bulk strength of the transition layer. Second, given that the nickel-based base material itself contains Fe components, actively adding Fe element to the transition layer can optimize the compatibility of the alloy system between the two, ensuring a strong metallurgical bond at the welding interface and guaranteeing the reliability of the connection.

[0032] Nickel-based alloy base materials mainly rely on the precipitation strengthening effect of solid solution + γ'. Laser cladding layers have a fast cooling rate and dense structure. Therefore, although the design is mainly based on solid solution strengthening, the performance of the resulting cladding layer is matched with that of the base material.

[0033] (2) The main alloying elements of GTAW welding materials are: Ni, Co, Cr, Fe, Mo, Ta, Nb, Al, Ti.

[0034] 1) The main alloying element of the nickel-based alloy base material is Ni. Therefore, the GTAW welding material is mainly Ni, which can ensure excellent welding connection between it and the base material.

[0035] 2) Co: The introduction of Co into nickel-based alloys comprehensively improves strength, toughness, and high-temperature performance. In terms of strength, Co atoms can dissolve extensively in the nickel-based γ-matrix, producing a significant solid solution strengthening effect, directly contributing to the increase in the strength of the alloy matrix. Regarding toughness, the addition of Co helps optimize the lattice mismatch between the γ / γ' phases and reduces stacking fault energy, thus maintaining good plasticity reserves and damage tolerance while improving strength, avoiding embrittlement caused by over-strengthening. For high-temperature performance, Co significantly enhances the alloy's creep resistance and microstructural stability by increasing the solid solution temperature and long-term stability of the γ' phase and slowing down the diffusion rate of alloying elements at high temperatures, ensuring its long-term performance under high-temperature service conditions. Furthermore, a certain amount of Co is also present in laser cladding layers; therefore, adding Co to GTAW welding materials can ensure the same high-temperature resistance as laser cladding layers.

[0036] 3) Cr element: The alloying design of Cr element mainly serves a dual purpose: First, Cr atoms dissolve in the γ-Ni matrix, generating effective solid solution strengthening by forming an atomic-scale lattice stress field, thereby ensuring that the transition layer reaches a strength level comparable to the base material. Second, under high-temperature service conditions, Cr, as an active element, can preferentially form a continuous, dense, and strongly adherent Cr2O3 protective film on the alloy surface through selective oxidation. This passivation film greatly hinders the inward diffusion of oxygen, thus fundamentally improving the oxidation resistance of the weld overlay alloy.

[0037] 4) Fe element: Fe is dissolved in the Ni matrix, which can reduce the stacking fault energy of the nickel matrix, thereby improving the toughness of the alloy. This allows the fault energy to be released through deformation during aging treatment, reducing the risk of strain-aged cracking. The addition of Fe can also expand the γ-Ni austenite phase region and stabilize the matrix structure. Furthermore, the base metal also contains a certain amount of Fe; therefore, adding Fe to GTAW welding materials contributes to excellent metallurgical bonding with the base metal.

[0038] 5) Mo: Nickel-based alloys are age-hardened and have high strength. Therefore, to avoid insufficient strength in butt joints, sufficient solid solution strengthening elements need to be added. Mo is an element that can significantly improve the strength of the Ni matrix without compromising its ductility and toughness.

[0039] 6) Ta (Ta): Similar to Mo, Ta can serve as an effective solid solution strengthening element to enhance the γ matrix of nickel-based alloys. However, Ta's core value lies in its unique stabilizing effect on the γ' phase (Ni3(Al, Ti)). During butt welding of aged nickel-based alloys, a certain amount of γ' phase will be present in the welding wire due to the addition of Al and Ti elements. The addition of Ta can effectively suppress the coarsening tendency of these strengthening phases during subsequent thermal cycling, stabilizing their quantity and morphology, thereby ensuring an excellent match between high-temperature strength and microstructure stability in the welded joint of the nickel-based alloy.

[0040] 7) Nitrogen B (Nb): In nickel-based alloys, the introduction of Nb is a crucial alloying strategy for optimizing overall performance. Its effects are mainly reflected in three aspects: First, Nb atoms can dissolve in the γ-Ni matrix, causing lattice distortion and providing direct solid solution strengthening, thus improving the alloy's room temperature and high temperature strength. More importantly, Nb is the core element for forming the γ'' strengthening phase (Ni3Nb). This phase is coherent with the matrix and produces a significant precipitation strengthening effect, which is the main source of increased yield strength. Simultaneously, Nb can combine with carbon to form stable MC-type carbides (such as NbC), distributed at grain boundaries, which helps refine grains and pin grain boundaries, thereby enhancing the alloy's creep resistance and long-term high-temperature structural stability. Therefore, through the synergistic effect of solid solution strengthening, precipitation strengthening, and carbide strengthening, Nb effectively improves the strength, creep resistance, and microstructural stability of nickel-based alloys.

[0041] 8) Al and Ti Elements: In GTAW welds of nickel-based alloys, the combined addition of Al and Ti is crucial for achieving precipitation strengthening of the weld metal. During post-weld cooling or subsequent heat treatment, Al and Ti react with the nickel matrix to precipitate dispersed, fine γ' phases (Ni3(Al, Ti)). These coherently ordered strengthening phases effectively hinder dislocation movement, thereby significantly improving the strength of the weld metal, especially its high-temperature strength and creep resistance. This is essential for matching the performance of the age-hardening base material and effectively preventing strength mismatch in the weld region. Furthermore, by precisely controlling the Al / Ti ratio, the lattice mismatch between the γ' phase and the matrix can be optimized, achieving high strength while maintaining good microstructural stability, ensuring the reliability of the welded joint under long-term high-temperature service.

[0042] The specific steps for preparing laser cladding materials are as follows: Step 1: Weigh out Ni powder (20.0-30.0%), Co powder (20.0-30.0%), Cr powder (10.0-20.0%), and the remainder Fe powder according to their respective mass percentages. The sum of the mass percentages of the above components shall be 100%. Step 2: Mix the raw material powders weighed in Step 1 and then vacuum melt them, using a gas atomization method to produce powder; In step 2, a vacuum melting equipment is used, with N2 as the atomizing gas and an atomization pressure of 6 MPa to 8 MPa. During the atomization process, the superheat of the melt is maintained at 100°C to 150°C. Step 3: Perform particle size sieving on the atomized powder to ensure that the sieved powder is within a certain particle size range; In step 3, the particle size range of the sieved powder is 25μm~53μm, that is, 270 mesh~500 mesh; the flowability requirement of the sieved powder is 25s / 100g~40s / 100g. Step 4: Vacuum package the prepared powder for later use.

[0043] The preparation method of GTAW welding material, and the specific steps are as follows: Step 1: Weigh out the following components by mass percentage: 30.0-40.0% Fe powder, 10.0-20.0% Co powder, 10.0-20.0% Ta powder, 3-6% Al powder, 3-6% Ti powder, with the remainder being Ni powder. The sum of the mass percentages of the above components should be 100%. Step 2: Place the weighed powder from Step 1 into a vacuum heating furnace and heat it at a temperature of 200℃~260℃ for 1h~2h to remove the water of crystallization from the powder; place the dried powder into a powder mixer for thorough mixing for 1h~2h. Step 3: Use Inconel 625 strip as the solder skin, with a thickness of 0.4 mm and a width of 7 mm; 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 2.6 mm. In step 3, the core filling rate is controlled between 20wt% and 25wt%. Step 4: After the first drawing process is completed, the die hole diameter is reduced one by one to finally obtain a flux-cored wire with a diameter of 1.2mm; 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.

[0044] This invention also provides a method for welding nickel-based alloys, using the aforementioned nickel-based alloy laser cladding + GTAW welding material for welding nickel-based alloys, such as... Figure 1 As shown, the specific steps are as follows: Step 1: Make a U-shaped bevel at the welding joint of the two nickel-based alloy plates to be welded. The top edge of the U-shaped bevel is a step. In step 1, the specific dimensional parameters of the U-shaped bevel are as follows: the angle on one side is 5°~8°, the blunt side dimension is 0.5mm~1.0mm; the width of the step at the top of the bevel is 15mm~20mm, and the step depth is 1mm~2mm. The bevel dimensions are as follows: Figure 2 As shown; Step 2: Perform laser cladding on the stepped surface at the top of the bevel opened in Step 1, selecting the laser cladding material mentioned above; In step 2, the laser power of laser cladding is 1kW~3kW, and the thickness of the cladding layer is greater than the step depth by 0.5mm~1.0mm; Step 3: Perform butt welding at the bevel prepared in Step 1 using hot wire GTAW automatic welding process, and use the GTAW welding material mentioned above as the welding material. In step 3, the welding current is 130 A ~ 200 A, the thickness of each layer is controlled between 1 mm and 2.5 mm, and the interpass temperature is controlled between 20℃ and 50℃.

[0045] Step 4: Perform two post-weld heat treatments on the resulting joint.

[0046] Step 4 is as follows: The first step is to rapidly heat the welded joint to 850℃~900℃ and hold it at that temperature for 4h~6h; the heating and cooling rates are both 100℃ / h~300℃ / h. The second step is to heat the above-mentioned joint to 800℃~830℃ and keep it at that temperature for 8h~12h; the heating rate and cooling rate are both 50℃ / h~100℃ / h.

[0047] Example 1 The specific steps for preparing laser cladding materials are as follows: Step 1: Weigh out Ni powder 20.0%, Co powder 20.0%, Cr powder 10.0%, and the remainder Fe powder according to their respective mass percentages. The sum of the mass percentages of the above components is 100%. Step 2: After mixing the raw material powders weighed in Step 1, vacuum melt the mixture and use gas atomization to produce powder. Step 3: Perform particle size sieving on the atomized alloy powder to ensure that the sieved alloy powder is within a certain particle size range.

[0048] Step 4: Vacuum package the prepared powder for later use.

[0049] In step 2, a vacuum melting device is used, with N2 as the atomizing gas, an atomization pressure of 6 MPa, and the superheat of the melt is maintained at 100°C during the atomization process.

[0050] In step 3, the particle size of the alloy powder after sieving is 25 μm; The flowability requirement for the sieved alloy powder is 25s / 100g.

[0051] The specific steps for preparing GTAW welding material are as follows: Step 1: Weigh out 30.0% Fe powder, 10.0% Co powder, 10.0% Ta powder, 3% Al powder, 3% Ti powder, and the remainder Ni powder according to their respective mass percentages. The sum of the mass percentages of the above components is 100%. The particle size of all raw material powders that make up the core is 100 mesh.

[0052] Step 2: Place the powder weighed in Step 1 into a vacuum heating furnace and heat it at 200℃ for 1 hour 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 Inconel 625 strip as the solder skin, with a thickness of 0.4 mm and a width of 7 mm; 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 2.6 mm. In step 3, the core filling rate is controlled at 20wt%; the Inconel 625 tape is 0.4mm thick and 7mm wide. Step 4: After the first drawing process is completed, the die hole diameter is reduced in sequence to finally obtain a flux-cored wire with a diameter of 1.2mm.

[0053] 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.

[0054] The nickel-based alloy laser cladding + GTAW welding material prepared in Example 1 was used for welding connection. The specific steps of the nickel-based alloy welding connection method are as follows (e.g. Figure 1 (as shown) (1) First, a U-shaped bevel is made at the welding joint of the two nickel-based alloy plates to be welded. The top edge of the U-shaped bevel is a step with a single-sided angle of 5° and a blunt edge dimension of 0.5mm. The top step width is 15mm and the step depth is 1mm. The bevel dimensions are as follows: Figure 2 As shown; (2) Next, laser cladding is performed on the surface of the step at the top of the bevel. The laser cladding material of the present invention is selected, the laser power is 1kW, and the cladding layer thickness is 1.5mm. (3) Then, hot wire GTAW automatic welding process is used to perform butt welding at the bevel opened in step (1). The welding material is the GTAW welding material in this invention, the welding current is 130A, the thickness of each layer is controlled at 1mm, and the interlayer temperature is controlled at 20℃.

[0055] (4) Finally, the above-mentioned nickel-based alloy joints undergo a two-step post-weld heat treatment process, as follows: (1) First step: rapidly heat the welded joint to 850℃ and hold for 4 hours. The heating and cooling rates are both 100℃ / h; (2) The second step is to heat the above-mentioned joint to 800℃ and keep it at that temperature for 8 hours. The heating rate and cooling rate are both 50℃ / h.

[0056] The joints after the above heat treatment were subjected to non-destructive testing, microstructural observation, and mechanical property testing. The results are as follows: (1) 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.

[0057] (2) NB / T 47014-2023 "Welding Procedure Qualification for Pressure Equipment" conducted a tensile test on the above-mentioned welded joint. The results showed that the tensile strength of the joint was 981 MPa, of which the tensile strength of the base material was 997 MPa. This indicates that the joint achieved excellent strength matching with the base material, and ultimately achieved uniform and consistent performance of the welded joint of aged nickel-based superalloy, solving the softening problem of aged iron-nickel-based superalloy joints under the GTAW process.

[0058] Example 2 The specific steps for preparing laser cladding materials are as follows: Step 1: Weigh out Ni powder 30.0%, Co powder 30.0%, Cr powder 20.0%, and the remainder Fe powder according to their respective mass percentages. The sum of the mass percentages of the above components is 100%. Step 2: After mixing the raw material powders weighed in Step 1, vacuum melt the mixture and use gas atomization to produce powder. Step 3: Perform particle size sieving on the atomized alloy powder to ensure that the sieved alloy powder is within a certain particle size range.

[0059] Step 4: Vacuum package the prepared powder for later use.

[0060] In step 2, a vacuum melting device is used, with N2 as the atomizing gas, an atomization pressure of 8 MPa, and the superheat of the melt is maintained at 150°C during the atomization process.

[0061] In step 3, the particle size range of the sieved alloy powder is 53 μm.

[0062] The flowability requirement for the sieved alloy powder is 40 s / 100g.

[0063] The specific steps for preparing GTAW welding material are as follows: Step 1: Weigh out 40.0% Fe powder, 20.0% Co powder, 20.0% Ta powder, 6% Al powder, 6% Ti powder, and the remainder Ni powder by mass percentage. The sum of the mass percentages of the above components is 100%. The particle size of all raw material powders that make up the core is 200 mesh.

[0064] Step 2: Place the weighed powder from Step 1 into a vacuum heating furnace and heat it at 260℃ for 2 hours to remove the water of crystallization from the powder; place the dried powder into a powder mixer for thorough mixing for 2 hours. Step 3: Use Inconel 625 strip as the solder skin, with a thickness of 0.4 mm and a width of 7 mm; 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 2.6 mm. In step 3, the core filling rate is controlled at 25wt%; the Inconel 625 tape is 0.4mm thick and 7mm wide. Step 4: After the first drawing process is completed, the die hole diameter is reduced in sequence to finally obtain a flux-cored wire with a diameter of 1.2mm.

[0065] 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.

[0066] A nickel-based alloy laser cladding + GTAW welding material prepared in Example 2 was used for welding connection. The specific steps of the nickel-based alloy welding connection method are as follows (e.g. Figure 1 (as shown) (1) First, a U-shaped bevel is made at the welding joint of the two nickel-based alloy plates to be welded. The top edge of the U-shaped bevel is a step with an angle of 8° on one side and a blunt edge dimension of 1.0 mm. The width of the step at the top of the bevel is 20 mm and the depth of the step is 2 mm. The dimensions of the bevel are as follows: Figure 2 As shown; (2) Next, laser cladding is performed on the surface of the step at the top of the bevel. The laser cladding material of the present invention is selected, the laser power is 3kW, and the cladding layer thickness is 3mm. (3) Then, hot wire GTAW automatic welding process is used to perform butt welding at the bevel opened in step (1). The welding material is the GTAW welding material in this invention, the welding current is 200A, the thickness of each layer is controlled at 2.5mm, and the interlayer temperature is controlled at 50℃.

[0067] (4) Finally, the above-mentioned nickel-based alloy joints undergo a two-step post-weld heat treatment process, as follows: (1) First step: rapidly heat the welded joint to 900℃ and hold for 6 hours. The heating rate and cooling rate are both 300℃ / h; (2) The second step is to heat the above joint to 830℃ and keep it at that temperature for 12 hours. The heating rate and cooling rate are both 100℃ / h.

[0068] The joints after the above heat treatment were subjected to non-destructive testing, microstructural observation, and mechanical property testing. The results are as follows: (1) 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.

[0069] (2) NB / T 47014-2023 "Welding Procedure Qualification for Pressure Equipment" conducted a tensile test on the above-mentioned welded joint. The results showed that the tensile strength of the joint was 985 MPa, of which the tensile strength of the base material was 997 MPa. This indicates that the joint achieved excellent strength matching with the base material, and ultimately achieved uniform and consistent performance of the welded joint of aged nickel-based superalloy, solving the softening problem of aged iron-nickel-based superalloy joints under the GTAW process.

[0070] Figure 3 The image shows the metallographic structure of the laser cladding layer prepared using Example 2. As can be seen from the figure, the laser cladding layer has a fine microstructure, primarily composed of γ-Ni. Figure 4 The image shows the metallographic structure of the GTAW weld prepared using Example 2. As can be seen from the figure, the GTAW butt weld microstructure is mainly composed of columnar dendritic γ-Ni.

[0071] Example 3 The specific steps for preparing laser cladding materials are as follows: Step 1: Weigh out Ni powder 25.0%, Co powder 25.0%, Cr powder 15.0%, and the remainder Fe powder according to their respective mass percentages. The sum of the mass percentages of the above components is 100%. Step 2: After mixing the raw material powders weighed in Step 1, vacuum melt the mixture and use gas atomization to produce powder. Step 3: Perform particle size sieving on the atomized alloy powder to ensure that the sieved alloy powder is within a certain particle size range.

[0072] Step 4: Vacuum package the prepared powder for later use.

[0073] In step 2, a vacuum melting device is used, with N2 as the atomizing gas, an atomization pressure of 7 MPa, and the superheat of the melt is maintained at 130°C during the atomization process.

[0074] In step 3, the particle size range of the sieved alloy powder is 35 μm.

[0075] The flowability requirement for the sieved alloy powder is 35s / 100g.

[0076] The specific steps for preparing GTAW welding material are as follows: Step 1: Weigh out the following components by mass percentage: 35.0% Fe powder, 15.0% Co powder, 15.0% Ta powder, 4.5% Al powder, 4.5% Ti powder, with the remainder being Ni powder. The sum of the mass percentages of the above components is 100%. The particle size of all raw material powders that make up the core is 200 mesh.

[0077] Step 2: Place the weighed powder from Step 1 into a vacuum heating furnace and heat it at 230℃ for 1.5 hours to remove the water of crystallization from the powder. After drying, place the powder into a powder mixer for thorough mixing for 1.5 hours. Step 3: Use Inconel 625 strip as the solder skin, with a thickness of 0.4 mm and a width of 7 mm; 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 2.6 mm. In step 3, the core filling rate is controlled at 22wt%; the Inconel 625 tape is 0.4mm thick and 7mm wide. Step 4: After the first drawing process is completed, the die hole diameter is reduced in sequence to finally obtain a flux-cored wire with a diameter of 1.2mm.

[0078] 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.

[0079] A nickel-based alloy laser cladding + GTAW welding material prepared in Example 3 was used for welding connection. The specific steps of the nickel-based alloy welding connection method are as follows (e.g. Figure 1 (as shown) (1) First, a U-shaped bevel is made at the welding joint of the two nickel-based alloy plates to be welded. The top edge of the U-shaped bevel is a step with a single-sided angle of 7° and a blunt edge dimension of 0.7mm. The top step width is 17mm and the step depth is 1.5mm. The bevel dimensions are as follows: Figure 2 As shown; (2) Next, laser cladding is performed on the surface of the step at the top of the bevel. The laser cladding material of the present invention is selected, the laser power is 2kW, and the cladding layer thickness is 2.2mm. (3) Then, hot wire GTAW automatic welding process is used to perform butt welding at the bevel opened in step (1). The welding material is the GTAW welding material in this invention, the welding current is 170A, the thickness of each layer is controlled at 1.7mm, and the interlayer temperature is controlled at 35℃.

[0080] (4) Finally, the above-mentioned nickel-based alloy joints undergo a two-step post-weld heat treatment process, as follows: (1) First step: rapidly heat the welded joint to 870℃ and hold for 5 hours. The heating and cooling rates are both 200℃ / h; (2) The second step is to heat the above-mentioned joint to 815℃ and keep it at that temperature for 10 hours. The heating rate and the cooling rate are both 75℃ / h.

[0081] The joints after the above heat treatment were subjected to non-destructive testing, microstructural observation, and mechanical property testing. The results are as follows: (1) 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.

[0082] (2) NB / T 47014-2023 "Welding Procedure Qualification for Pressure Equipment" conducted a tensile test on the above-mentioned welded joint. The results showed that the tensile strength of the joint was 990 MPa, of which the tensile strength of the base material was 997 MPa. This indicates that the joint achieved excellent strength matching with the base material, and ultimately achieved uniform and consistent performance of the welded joint of aged nickel-based superalloy, solving the softening problem of aged iron-nickel-based superalloy joints under the GTAW process.

[0083] Example 4 The specific steps for preparing laser cladding materials are as follows: Step 1: Weigh out Ni powder 21.0%, Co powder 21.0%, Cr powder 11.0%, and the remainder Fe powder according to their respective mass percentages. The sum of the mass percentages of the above components is 100%. Step 2: After mixing the raw material powders weighed in Step 1, vacuum melt the mixture and use gas atomization to produce powder. Step 3: Perform particle size sieving on the atomized alloy powder to ensure that the sieved alloy powder is within a certain particle size range.

[0084] Step 4: Vacuum package the prepared powder for later use.

[0085] In step 2, a vacuum melting device is used, with N2 as the atomizing gas, an atomization pressure of 6.5 MPa, and the superheat of the melt is maintained at 110°C during the atomization process.

[0086] In step 3, the particle size range of the sieved alloy powder is 30 μm.

[0087] The flowability requirement for the sieved alloy powder is 35s / 100g.

[0088] The specific steps for preparing GTAW welding material are as follows: Step 1: Weigh out Fe powder 31.0%, Co powder 11.0%, Ta powder 11.0%, Al powder 3.5%, Ti powder 3.5%, and the remainder Ni powder according to their respective mass percentages. The sum of the mass percentages of the above components is 100%. The particle size of all raw material powders that make up the core is 100 mesh.

[0089] Step 2: Place the weighed powder from Step 1 into a vacuum heating furnace and heat it at 210℃ for 1.2 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 Inconel 625 strip as the solder skin, with a thickness of 0.4 mm and a width of 7 mm; 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 2.6 mm. In step 3, the core filling rate is controlled at 20wt%; the Inconel 625 tape is 0.4mm thick and 7mm wide. Step 4: After the first drawing process is completed, the die hole diameter is reduced in sequence to finally obtain a flux-cored wire with a diameter of 1.2mm.

[0090] 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.

[0091] A nickel-based alloy laser cladding + GTAW welding material prepared in Example 4 was used for welding connection. The specific steps of the nickel-based alloy welding connection method are as follows (e.g.) Figure 1 (as shown) (1) First, a U-shaped bevel is made at the welding joint of the two nickel-based alloy plates to be welded. The top edge of the U-shaped bevel is a step with a single-sided angle of 5.5° and a blunt edge dimension of 0.6 mm. The top step width is 16 mm and the step depth is 1.1 mm. The bevel dimensions are as follows: Figure 2 As shown; (2) Next, laser cladding is performed on the surface of the step at the top of the bevel. The laser cladding material of the present invention is selected, the laser power is 1.5kW, and the thickness of the cladding layer is greater than 0.6mm of the step depth. (3) Then, hot wire GTAW automatic welding process is used to perform butt welding at the bevel opened in step (1). The welding material is the GTAW welding material in this invention, the welding current is 140A, the thickness of each layer is controlled at 1.1mm, and the interlayer temperature is controlled at 21℃.

[0092] (4) Finally, the above-mentioned nickel-based alloy joints undergo a two-step post-weld heat treatment process, as follows: (1) First step: rapidly heat the welded joint to 855℃ and hold for 4.1h. The heating and cooling rates are both 110℃ / h; (2) The second step is to heat the above-mentioned joint to 810℃ and keep it at that temperature for 8.5 hours. The heating rate and cooling rate are both 60℃ / h.

[0093] The joints after the above heat treatment were subjected to non-destructive testing, microstructural observation, and mechanical property testing. The results are as follows: (1) 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.

[0094] (2) NB / T 47014-2023 "Welding Procedure Qualification for Pressure Equipment" conducted a tensile test on the above-mentioned welded joint. The results showed that the tensile strength of the joint was 988 MPa, of which the tensile strength of the base material was 997 MPa. This indicates that the joint achieved excellent strength matching with the base material, and ultimately achieved uniform and consistent performance of the welded joint of aged nickel-based superalloy, solving the softening problem of aged iron-nickel-based superalloy joints under the GTAW process.

[0095] Example 5 The specific steps for preparing laser cladding materials are as follows: Step 1: Weigh out Ni powder 22.0%, Co powder 22.0%, Cr powder 12.0%, and the remainder Fe powder according to their respective mass percentages. The sum of the mass percentages of the above components is 100%. Step 2: After mixing the raw material powders weighed in Step 1, vacuum melt the mixture and use gas atomization to produce powder. Step 3: Perform particle size sieving on the atomized alloy powder to ensure that the sieved alloy powder is within a certain particle size range.

[0096] Step 4: Vacuum package the prepared powder for later use.

[0097] In step 2, a vacuum melting device is used, with N2 as the atomizing gas, an atomization pressure of 6.7 MPa, and the superheat of the melt is maintained at 120°C during the atomization process.

[0098] In step 3, the particle size range of the sieved alloy powder is 36 μm.

[0099] The flowability requirement for the sieved alloy powder is 38s / 100g.

[0100] The specific steps for preparing GTAW welding material are as follows: Step 1: Weigh out the following components by mass percentage: 35.5% Fe powder, 15.5% Co powder, 15.5% Ta powder, 3.5% Al powder, 4.1% Ti powder, with the remainder being Ni powder. The sum of the mass percentages of the above components is 100%. The particle size of all raw material powders that make up the core is 100 mesh.

[0101] Step 2: Place the weighed powder from Step 1 into a vacuum heating furnace and heat it at 222℃ for 1.8 hours to remove the water of crystallization from the powder. After drying, place the powder into a powder mixer for thorough mixing for 1.8 hours. Step 3: Use Inconel 625 strip as the solder skin, with a thickness of 0.4 mm and a width of 7 mm; 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 2.6 mm. In step 3, the core filling rate is controlled at 25 wt%. Step 4: After the first drawing process is completed, the die hole diameter is reduced in sequence to finally obtain a flux-cored wire with a diameter of 1.2mm.

[0102] 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.

[0103] The nickel-based alloy laser cladding + GTAW welding material prepared in Example 5 was used for welding connection. The specific steps of the nickel-based alloy welding connection method are as follows (e.g. Figure 1(as shown) (1) First, a U-shaped bevel is made at the welding joint of the two nickel-based alloy plates to be welded. The top edge of the U-shaped bevel is a single step with a single-sided angle of 6.2° and a blunt edge dimension of 0.8mm. The width of the top step is 16.5mm and the step depth is 1.65mm. The bevel dimensions are as follows: Figure 2 As shown; (2) Next, laser cladding is performed on the surface of the step at the top of the bevel. The laser cladding material of the present invention is selected, the laser power is 1.8kW, and the cladding layer thickness is 2.6mm. (3) Then, hot wire GTAW automatic welding process is used to perform butt welding at the bevel opened in step (1). The welding material is the GTAW welding material in this invention, the welding current is 180A, the thickness of each layer is controlled at 2.3mm, and the interlayer temperature is controlled at 45℃.

[0104] (4) Finally, the above-mentioned nickel-based alloy joints undergo a two-step post-weld heat treatment process, as follows: (1) First step: rapidly heat the welded joint to 875℃ and hold for 5.5 hours. The heating and cooling rates are both 260℃ / h; (2) The second step is to heat the above-mentioned joint to 825℃ and keep it at that temperature for 11 hours. The heating rate and the cooling rate are both 80℃ / h.

[0105] The joints after the above heat treatment were subjected to non-destructive testing, microstructural observation, and mechanical property testing. The results are as follows: (1) 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.

[0106] (2) NB / T 47014-2023 "Welding Procedure Qualification for Pressure Equipment" conducted a tensile test on the above-mentioned welded joint. The results showed that the tensile strength of the joint was 997 MPa, of which the tensile strength of the base material was 997 MPa. This indicates that the joint achieved excellent strength matching with the base material, and ultimately achieved uniform and consistent performance of the welded joint of aged nickel-based superalloy, solving the softening problem of aged iron-nickel-based superalloy joints under the GTAW process.

[0107] Example 6 The specific steps for preparing laser cladding materials are as follows: Step 1: Weigh out Ni powder 29.0%, Co powder 29.0%, Cr powder 19.0%, and the remainder Fe powder according to their respective mass percentages. The sum of the mass percentages of the above components is 100%. Step 2: After mixing the raw material powders weighed in Step 1, vacuum melt the mixture and use gas atomization to produce powder. Step 3: Perform particle size sieving on the atomized alloy powder to ensure that the sieved alloy powder is within a certain particle size range.

[0108] Step 4: Vacuum package the prepared powder for later use.

[0109] In step 2, a vacuum melting device is used, with N2 as the atomizing gas, an atomization pressure of 7.9 MPa, and the superheat of the melt is maintained at 145°C during the atomization process.

[0110] In step 3, the particle size range of the sieved alloy powder is 50 μm.

[0111] The flowability requirement for the sieved alloy powder is 25s / 100g.

[0112] The specific steps for preparing GTAW welding material are as follows: Step 1: Weigh out Fe powder 39.0%, Co powder 19.0%, Ta powder 19.0%, Al powder 5.9%, Ti powder 5.9%, and the remainder Ni powder according to their respective mass percentages. The sum of the mass percentages of the above components is 100%. The particle size of all raw material powders that make up the core is 100 mesh.

[0113] Step 2: Place the weighed powder from Step 1 into a vacuum heating furnace and heat it at 255℃ for 1.9 hours to remove the water of crystallization from the powder. After drying, place the powder into a powder mixer for thorough mixing for 1.9 hours. Step 3: Use Inconel 625 strip as the solder skin, with a thickness of 0.4 mm and a width of 7 mm; 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 2.6 mm. In step 3, the core filling rate is controlled at 23wt%; the Inconel 625 tape is 0.4mm thick and 7mm wide. Step 4: After the first drawing process is completed, the die hole diameter is reduced in sequence to finally obtain a flux-cored wire with a diameter of 1.2mm.

[0114] 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.

[0115] The nickel-based alloy laser cladding + GTAW welding material prepared in Example 6 was used for welding connection. The specific steps of the nickel-based alloy welding connection method are as follows (e.g. Figure 1 (as shown) (1) First, a U-shaped bevel is made at the welding joint of the two nickel-based alloy plates to be welded. The top edge of the U-shaped bevel is a step, with a single-sided angle of 7.8° and a blunt edge dimension of 0.98mm. The top step width is 19mm and the step depth is 1.9mm. The bevel dimensions are as follows: Figure 2 As shown; (2) Next, laser cladding is performed on the surface of the step at the top of the bevel. The laser cladding material of the present invention is selected, the laser power is 2.9kW, and the cladding layer thickness is 2.6mm. (3) Then, hot wire GTAW automatic welding process is used to perform butt welding at the bevel opened in step (1). The welding material is the GTAW welding material in this invention, the welding current is 190A, the thickness of each layer is controlled at 2.4mm, and the interlayer temperature is controlled at 29℃.

[0116] (4) Finally, the above-mentioned nickel-based alloy joints undergo a two-step post-weld heat treatment process, as follows: (1) First step: rapidly heat the welded joint to 890℃ and hold for 5.9h. The heating and cooling rates are both 290℃ / h; (2) The second step is to heat the above-mentioned joint to 829℃ and keep it at that temperature for 11.5h. The heating rate and cooling rate are both 95℃ / h.

[0117] The joints after the above heat treatment were subjected to non-destructive testing, microstructural observation, and mechanical property testing. The results are as follows: (1) 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.

[0118] (2) NB / T 47014-2023 "Welding Procedure Qualification for Pressure Equipment" conducted a tensile test on the above-mentioned welded joint. The results showed that the tensile strength of the joint was 1001 MPa, of which the tensile strength of the base material was 997 MPa. This indicates that the joint achieved excellent strength matching with the base material, and ultimately achieved uniform and consistent performance of the welded joint of aged nickel-based superalloy, solving the softening problem of aged iron-nickel-based superalloy joints under the GTAW process.

Claims

1. A nickel-based alloy laser cladding + GTAW bonding material, characterized in that, Including laser cladding materials and GTAW welding materials; The laser cladding material comprises the following components by mass percentage: 20.0-30.0% Ni powder, 20.0-30.0% Co powder, 10.0-20.0% Cr powder, and the remainder is Fe powder, with the sum of the mass percentages of the above components being 100%. GTAW welding material includes a flux core and a solder coating. The flux core comprises the following components by mass percentage: 30.0-40.0% Fe powder, 10.0-20.0% Co powder, 10.0-20.0% Ta powder, 3-6% Al powder, 3-6% Ti powder, and the remainder is Ni powder. The sum of the mass percentages of the above components is 100%.

2. The nickel-based alloy laser cladding + GTAW bonding material according to claim 1, characterized in that, The GTAW welding material used has an Inconel 625 strip with a thickness of 0.4 mm and a width of 7 mm.

3. The nickel-based alloy laser cladding + GTAW bonding material according to claim 1, characterized in that, The flux-cored filling rate of GTAW welding material is controlled at 20wt%~25wt%.

4. The nickel-based alloy laser cladding + GTAW bonding material according to claim 1, characterized in that, The specific steps for preparing the laser cladding material are as follows: Step 1: Weigh out Ni powder (20.0-30.0%), Co powder (20.0-30.0%), Cr powder (10.0-20.0%), and the remainder Fe powder according to their respective mass percentages. The sum of the mass percentages of the above components shall be 100%. Step 2: Mix the raw material powders weighed in Step 1 and then vacuum melt them, using a gas atomization method to produce powder; In step 2, a vacuum melting equipment is used, with N2 as the atomizing gas and an atomization pressure of 6 MPa to 8 MPa. During the atomization process, the superheat of the melt is maintained at 100°C to 150°C. Step 3: Perform particle size sieving on the atomized powder; In step 3, the particle size range of the sieved powder is 25μm~53μm, that is, 270 mesh~500 mesh; the flowability requirement of the sieved powder is 25s / 100g~40s / 100g. Step 4: Vacuum package the prepared powder for later use.

5. The nickel-based alloy laser cladding + GTAW bonding material according to claim 1, characterized in that, The specific steps for preparing the GTAW welding material are as follows: Step 1: Weigh out the following components by mass percentage: 30.0-40.0% Fe powder, 10.0-20.0% Co powder, 10.0-20.0% Ta powder, 3-6% Al powder, 3-6% Ti powder, with the remainder being Ni powder. The sum of the mass percentages of the above components should be 100%. Step 2: Place the weighed powder from Step 1 into a vacuum heating furnace and heat it at a temperature of 200℃~260℃ for 1h~2h to remove the water of crystallization from the powder; place the dried powder into a powder mixer for thorough mixing for 1h~2h. Step 3: Use Inconel 625 strip as the solder coating; 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. In step 3, the core filling rate is controlled between 20wt% and 25wt%. Step 4: After the first drawing process is completed, the die hole diameter is reduced one by one to finally obtain a flux-cored wire with a diameter of 1.2mm; 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.

6. A method for welding nickel-based alloys, characterized in that, The nickel-based alloy laser cladding + GTAW welding material described in claim 1 is used for nickel-based alloy welding connections, and the specific steps are as follows: Step 1: Make a U-shaped bevel at the welding joint of the two nickel-based alloy plates to be welded. The top edge of the U-shaped bevel is a step. Step 2: Perform laser cladding on the stepped surface at the top of the bevel created in Step 1, using the laser cladding material described in claim 1; Step 3: Perform butt welding at the bevel prepared in Step 1 using hot wire GTAW automatic welding process, and use the GTAW welding material described in claim 1 as the welding material. Step 4: Perform two post-weld heat treatments on the resulting joint.

7. The nickel-based alloy welding connection method according to claim 6, characterized in that, In step 1, the specific dimensional parameters of the U-shaped bevel are as follows: the angle of one side is 5°~8°, the blunt side dimension is 0.5mm~1.0mm; the width of the step at the top of the bevel is 15mm~20mm, and the step depth is 1mm~2mm. In step 2, the laser power of laser cladding is 1kW~3kW, and the thickness of the cladding layer is greater than the step depth by 0.5mm~1.0mm; In step 3, the welding current is 130 A ~ 200 A, the thickness of each layer is controlled between 1 mm and 2.5 mm, and the interpass temperature is controlled between 20℃ and 50℃.

8. The nickel-based alloy welding connection method according to claim 6, characterized in that, Step 4 specifically involves: The first step is to rapidly heat the welded joint to 850℃~900℃ and hold it at that temperature for 4h~6h; the heating and cooling rates are both 100℃ / h~300℃ / h. The second step is to heat the above-mentioned joint to 800℃~830℃ and keep it at that temperature for 8h~12h; the heating rate and cooling rate are both 50℃ / h~100℃ / h.

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