Corrosion-resistant nickel-based alloy welding wire and production process thereof

Abstract

The application belongs to the technical field of nickel-based alloy welding wire, and discloses a kind of corrosion-resistant nickel-based alloy welding wire and its production process, including the following components by mass percentage: nickel: 50-58%, chromium: 16-24%, molybdenum: 8-10%, niobium + tantalum: 3.5-5.5%, copper: 3-4.5%, tungsten: 3-4%, tin: 0.5-1.0%, rare earth elements: 0.1-0.3%, grain boundary optimization agent: 0.1-0.5%, nano-enhanced phase: 2-5%, the balance is Fe and other inevitable impurities. The application realizes the comprehensive improvement of corrosion resistance, high-temperature mechanical properties and welding process performance through the synergistic effect of multi-alloy design, nano-enhanced phase composite and gradient coating. The welding wire matrix is based on nickel, and by accurately controlling the atomic proportion of chromium, molybdenum and tungsten, a dense and self-repairing gradient oxidation film is formed, significantly improving the resistance to chloride ion penetration and high-temperature oxidation capacity. Thus, the welding wire has excellent corrosion resistance, high-temperature strength and welding adaptability.

Description

Technical Field

[0001] This invention relates to the field of nickel-based alloy welding wire technology, and in particular to a corrosion-resistant nickel-based alloy welding wire and its manufacturing process. Background Technology

[0002] Nickel-based alloy welding wire, as a core product in the field of welding materials, is technologically developed based on the deep integration of the unique properties of nickel-based alloys and industrial needs. Nickel-based alloys use nickel as the base material and add elements such as chromium, molybdenum, tungsten, and cobalt to form a solid solution strengthening system. They possess excellent high-temperature oxidation resistance, resistance to localized corrosion (such as pitting and crevice corrosion), and high-temperature strength stability, especially in the presence of Cl. - Nickel-based alloy welding wire exhibits performance advantages that traditional stainless steel cannot match in extreme environments with corrosive media such as H2S and sulfuric acid. As the service conditions of equipment in aerospace, nuclear power, marine engineering, and petrochemical fields become increasingly demanding, the application scenarios of nickel-based alloy welding wire have expanded from conventional corrosion-resistant environments to key areas such as high-temperature and high-pressure gas turbine components, nuclear reactor internals, and deep-sea oil and gas pipelines, becoming a core material for ensuring the long-term safe operation of equipment.

[0003] Nickel-based alloy welding wires have evolved from single-component to multi-component composites. Early nickel-copper alloys (such as Monel 400) possessed basic corrosion resistance, but were prone to stress corrosion cracking in high-temperature chloride or molten salt environments. Subsequent developments of nickel-chromium-molybdenum alloys (such as Inconel 625 and Hastelloy C-276) significantly improved the self-healing ability of the passivation film and its resistance to intergranular corrosion by optimizing the Cr / (Mo+W) atomic ratio (2.5-3.5) and adding grain boundary stabilizing elements such as niobium and titanium.

[0004] However, existing technologies still have significant drawbacks: First, traditional welding wires experience a sharp increase in corrosion rate at high temperatures (>800℃) and in highly oxidizing acidic environments (such as concentrated sulfuric acid) due to insufficient oxide film stability. Second, the poor fluidity and shallow penetration of the molten pool during welding easily lead to incomplete fusion defects and increased susceptibility to hot cracking. Third, the segregation of impurity elements (sulfur, phosphorus) and the precipitation of carbides at grain boundaries result in a mismatch between the mechanical properties of the weld (such as tensile strength and impact toughness) and the base metal. Furthermore, increasingly stringent environmental protection measures demand low-carbon production processes for welding wires, while existing high-energy-consuming smelting and coating processes are insufficient to meet green manufacturing standards.

[0005] Current technological bottlenecks lie in the synergistic optimization of composition, process, and performance. Although the introduction of nano-reinforcing phases (such as boron nitride and CeB6) can improve melt flow and inhibit crack propagation, their dispersion uniformity and interfacial bonding strength are still limited by ball milling process parameters. Gradient coating techniques (such as Ni-Cr-Mo / TiC bilayer structures) can delay the degradation of Cl... -While the coating can penetrate, the difference in thermal expansion coefficients between the coating and the substrate at high temperatures can easily lead to peeling.

[0006] Therefore, how to provide a corrosion-resistant nickel-based alloy welding wire and its production process is an urgent problem to be solved. Summary of the Invention

[0007] This invention provides a corrosion-resistant nickel-based alloy welding wire and its manufacturing process to solve the aforementioned technical problems in the prior art.

[0008] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or to describe the scope of protection of these embodiments. Its sole purpose is to present some concepts in a simple form as a prelude to the detailed description that follows.

[0009] According to a first aspect of the present invention, a corrosion-resistant nickel-based alloy welding wire is provided.

[0010] In one embodiment, the corrosion-resistant nickel-based alloy welding wire comprises the following components by weight percentage:

[0011] Nickel: 50-58%, Chromium: 16-24%, Molybdenum: 8-10%, Niobium + Tantalum: 3.5-5.5%, Copper: 3-4.5%, Tungsten: 3-4%, Tin: 0.5-1.0%, Rare Earth Elements: 0.1-0.3%, Grain Boundary Optimizer: 0.1-0.5%, Nano-Reinforcing Phase: 2-5%, Balance: Fe and other unavoidable impurities.

[0012] In one embodiment, the rare earth element is a mixture of cerium and lanthanum, and the mass ratio of cerium to lanthanum is 1:1.

[0013] In one embodiment, the mass ratio of tin to copper is 1:3 to 1:5, which is used to suppress high-temperature welding cracks.

[0014] In one embodiment, the nano-reinforcing phase includes at least one of boron nitride nanosheets, cerium hexaboride, titanium carbide, vanadium carbide, or nickel-coated cerium oxide nanocapsules, and the particle size of the nano-reinforcing phase is 20-50 nm.

[0015] In one embodiment, the grain boundary optimizer includes at least one of zirconium and tellurium, used to suppress intergranular corrosion and carbide segregation.

[0016] In one embodiment, the atomic percentages of chromium, molybdenum, and tungsten satisfy Cr / (Mo+W) = 2.5-3.5.

[0017] In one embodiment, the welding wire has a tensile strength ≥680MPa, a high-temperature creep strength ≥240MPa at 750℃, and a corrosion rate ≤0.08mm / y in a molten salt environment.

[0018] In one embodiment, the impurities are controlled as follows: sulfur ≤ 0.005%, phosphorus ≤ 0.008%, and iron content ≤ 7%, with a sulfur to phosphorus mass ratio ≤ 0.6.

[0019] In one embodiment, the surface of the welding wire is coated with a gradient coating, which includes an inner layer and an outer layer. The inner layer is a nano-Ni-Cr-Mo alloy layer with a thickness of 0.5-1.5 μm, and the outer layer is a TiC ceramic layer or a CeB6-doped Ni-Cr-Mo layer.

[0020] According to a second aspect of the present invention, a manufacturing process for corrosion-resistant nickel-based alloy welding wire is provided.

[0021] In one embodiment, the manufacturing process of the corrosion-resistant nickel-based alloy welding wire includes:

[0022] Raw materials were selected according to a preset composition ratio, and nano-reinforced phase materials were prepared by high-energy ball milling.

[0023] The weighed raw materials were subjected to vacuum induction melting at a vacuum degree ≤1×10⁻⁶. -2 Under Pa conditions, nickel, chromium, molybdenum, tungsten and iron-based materials are added in sequence. The melting temperature is raised to 1550-1600℃ and held for 30 minutes for deoxidation. The melt is homogenized by electromagnetic stirring. Then niobium, tantalum, copper, tin and rare earth elements are added. After the melt is fully mixed, it is poured into a water-cooled copper mold to form an ingot.

[0024] The ingot was used as a consumable electrode for electroslag remelting. The slag system was CaF2-CaO-Al2O3. After homogenization annealing at 1200-1250℃ for 24 hours, it was heated to 1180-1200℃ for multi-directional forging.

[0025] The billet is processed into Φ8mm wire rod through multiple hot rolling passes. After the wire rod is pickled to remove the oxide scale, it is cold drawn and intermediate annealed to eliminate work hardening. Then it is precision drawn to the target diameter in multiple passes.

[0026] The nano-reinforcing phase is mixed with alloy powder by ball milling dispersion process, and then deposited stepwise on the surface of welding wire using arc ion plating and magnetron sputtering technology to form a gradient coating.

[0027] Grain boundary optimization is achieved through vacuum annealing. The mixture of H2 and Ar gas is introduced into an environment of 850℃ and kept at that temperature for 2 hours to promote the segregation of grain boundary optimizers at grain boundaries, forming ZrO2 nanoparticles and Te-Cu eutectic phase. Finally, solid solution strengthening and vacuum annealing at 550℃ for 30 minutes are performed to eliminate residual stress, resulting in the finished nickel-based alloy welding wire.

[0028] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0029] 1. Through multi-element alloying design, nano-reinforced phase composite, and gradient coating synergistic effect, the overall corrosion resistance, high-temperature mechanical properties, and welding processability are comprehensively improved. The welding wire matrix is ​​nickel-based, and by precisely controlling the atomic ratio of chromium, molybdenum, and tungsten, a dense and self-healing gradient oxide film is formed, which significantly improves the resistance to chloride ion penetration and high-temperature oxidation. The addition of niobium, tantalum composite carbides and rare earth elements optimizes the grain boundary structure and inhibits intergranular corrosion and carbide segregation. The nano-reinforced phase reduces the spatter rate by improving the fluidity of the molten pool, while also improving the creep resistance. The surface gradient coating further blocks the diffusion path of corrosive media, ensuring long-term service stability in extreme environments, thus giving the welding wire excellent corrosion resistance, high-temperature strength, and welding adaptability.

[0030] 2. A breakthrough improvement in corrosion resistance is achieved through dual optimization of passivation film forming elements and grain boundary engineering; chromium, molybdenum, and tungsten form a gradient oxide film in a specific atomic ratio: the outer layer of molybdenum- and tungsten-rich oxides (MoO3, W2O5) preferentially consumes Cl. - Ions slow down the penetration of corrosive media; the inner chromium-rich oxide (Cr2O3) layer provides a continuous and dense protective layer, with a passivation film rupture potential ≥1.2V (vs. SCE). The synergistic effect of rare earth elements (Ce / La) and zirconium purifies grain boundaries, adsorbs sulfur and phosphorus impurities, and forms CeCrO3 composite oxides, reducing the intergranular corrosion rate to less than 40% of that of traditional welding wire. Nickel-coated cerium oxide (Ni@CeO2) nanocapsules release active Ce in high-temperature corrosive environments. 3+ It dynamically repairs oxide film defects and significantly extends the passivation film life. In addition, the surface TiC ceramic layer remains chemically inert in a molten salt environment, inhibiting the initiation of local pitting corrosion.

[0031] 3. Through multi-scale synergy of solid solution strengthening, dispersion strengthening, and grain boundary optimization, the high-temperature mechanical properties and welding process stability are simultaneously improved. High-entropy alloying of cobalt and manganese in the matrix forms a Ni-Co-Mn solid solution, enhancing high-temperature phase stability. Niobium-tantalum composite carbides (NbC / TaC) and nano-reinforcing phases (VC, BN) act as dispersion strengthening phases, suppressing dislocation slip and grain boundary migration, thus increasing the creep strength at 750℃ to ≥240MPa (1000h). Grain boundary optimizers (Zr, Te) refine the grains to 5-8μm, suppressing the tendency for high-temperature loss-of-ductility cracking (DDC), and achieving an impact toughness (20℃) ≥120J / cm. 2 In the welding process, boron nitride nanosheets (BN) reduce the molten pool viscosity, resulting in a spatter rate of ≤5% and a wetting angle of ≤15°, making them suitable for all-position automated welding; the gradient coating maintains low porosity (≤15%) at high temperatures, avoiding coating peeling caused by thermal cycling.

[0032] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0033] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0034] Figure 1 This is a flowchart illustrating a production process for a corrosion-resistant nickel-based alloy welding wire according to an exemplary embodiment. Detailed Implementation

[0035] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0036] In a first aspect, an embodiment of a corrosion-resistant nickel-based alloy welding wire of the present invention is provided.

[0037] In this optional embodiment, the corrosion-resistant nickel-based alloy welding wire comprises the following components by weight percentage:

[0038] Nickel (Ni): 50-58%, Chromium (Cr): 16-24%, Molybdenum (Mo): 8-10%, Niobium (Nb) + Tantalum (Ta): 3.5-5.5%, Copper (Cu): 3-4.5%, Tungsten (W): 3-4%, Tin (Sn): 0.5-1.0%, Rare Earth Elements: 0.1-0.3%, Grain Boundary Optimizer: 0.1-0.5%, Nano-Reinforcing Phase: 2-5%, Balance: Fe and other unavoidable impurities.

[0039] In this optional embodiment, the rare earth element is a mixture of cerium (Ce) and lanthanum (La), and the mass ratio of cerium (Ce) to lanthanum (La) is 1:1.

[0040] In this alternative embodiment, the mass ratio of tin (Sn) to copper (Cu) is 1:3 to 1:5, which is used to suppress high-temperature welding cracks.

[0041] In this optional embodiment, the nano-reinforcing phase includes at least one of boron nitride nanosheets (BN), cerium hexaboride (CeB6), titanium carbide (TiC), vanadium carbide (VC), or nickel-coated cerium oxide (Ni@CeO2) nanocapsules, and the particle size of the nano-reinforcing phase is 20-50 nm.

[0042] In this alternative embodiment, the grain boundary optimizer includes at least one of zirconium (Zr) and tellurium (Te) to suppress intergranular corrosion and carbide segregation.

[0043] In this alternative embodiment, the atomic percentages of chromium (Cr), molybdenum (Mo), and tungsten (W) satisfy Cr / (Mo+W) = 2.5-3.5.

[0044] In this optional embodiment, the welding wire has a tensile strength ≥680MPa, a high-temperature creep strength ≥240MPa (1000h) at 750℃, and a corrosion rate ≤0.08mm / y in a molten salt (NaCl-KCl) environment.

[0045] In this optional embodiment, the impurities are controlled as follows: sulfur (S) ≤ 0.005%, phosphorus (P) ≤ 0.008%, and when the Fe content is ≤ 7%, the S / P mass ratio is ≤ 0.6.

[0046] In this optional embodiment, the surface of the welding wire is coated with a gradient coating, which includes an inner layer and an outer layer. The inner layer is a nano-Ni-Cr-Mo alloy layer with a thickness of 0.5-1.5 μm, and the outer layer is a nano-Ni-Cr-Mo alloy layer with a thickness of 0.2-0.5 μm.

[0047] Secondly, Figure 1 An embodiment of the manufacturing process of a corrosion-resistant nickel-based alloy welding wire according to the present invention is shown.

[0048] In this optional embodiment, the manufacturing process of the corrosion-resistant nickel-based alloy welding wire includes:

[0049] S101. Select raw materials according to the preset component ratio and prepare nano-reinforced phase materials by high-energy ball milling.

[0050] S102. The weighed raw materials are subjected to vacuum induction melting, with a vacuum degree ≤1×10⁻⁶. -2Under Pa conditions, nickel, chromium, molybdenum, tungsten and iron-based materials are added in sequence. The melting temperature is raised to 1550-1600℃ and held for 30 minutes for deoxidation. The melt is homogenized by electromagnetic stirring. Then niobium, tantalum, copper, tin and rare earth elements are added. After the melt is fully mixed, it is poured into a water-cooled copper mold to form an ingot.

[0051] S103. The ingot is used as a consumable electrode for electroslag remelting. The slag system is CaF2-CaO-Al2O3. After homogenization annealing at 1200-1250℃ for 24 hours, it is heated to 1180-1200℃ for multi-directional forging.

[0052] S104. The billet is processed into Φ8mm wire rod through multiple hot rolling passes. After the wire rod is pickled to remove the oxide scale, it is cold drawn and intermediate annealed to eliminate work hardening. Then it is precision drawn to the target diameter in multiple passes.

[0053] S105. The nano-reinforcing phase is mixed with alloy powder through ball milling dispersion process, and then deposited stepwise on the surface of the welding wire using arc ion plating and magnetron sputtering technology to form a gradient coating.

[0054] S106. Grain boundary optimization is achieved through vacuum annealing. H2 / Ar mixed gas is introduced into an environment of 850℃ and kept at that temperature for 2 hours to promote the segregation of grain boundary optimizer at grain boundaries, forming ZrO2 nanoparticles and Te-Cu eutectic phase. Finally, solid solution strengthening and vacuum annealing at 550℃ for 30 minutes are performed to eliminate residual stress, resulting in the finished nickel-based alloy welding wire.

[0055] The present invention will be explained in detail below with reference to specific embodiments.

[0056] Example 1

[0057] 1. Corrosion-resistant nickel-based alloy welding wire, comprising the following components by weight percentage:

[0058] Nickel (Ni) 58g, Chromium (Cr) 18.8g, Molybdenum (Mo) 9g, Niobium + Tantalum (Nb + Ta) 3.5g, Copper (Cu) 3g, Tungsten (W) 3.5g, Tin (Sn) 0.5g, Rare Earth Elements (Ce / La=1:1) 0.2g, Zirconium (Zr) 0.3g, Nano-reinforcing Phase (BN + Ni@CeO2) 2.2g, Fe balance 1g.

[0059] 2. Preparation process (simplified):

[0060] Vacuum induction melting (vacuum degree ≤ 1×10) -2 Pa, temperature 1580℃, holding time 30 min), electroslag remelting (slag system CaF2-CaO-Al2O3, current density 1.0 A / mm²). 2 Homogenization annealing (1230℃, 24h);

[0061] Hot-rolled to Φ8mm wire rod, cold-drawn to Φ1.6mm, with a gradient coating on the surface (inner Ni-Cr-Mo alloy layer 1.0μm, outer TiC ceramic layer 0.3μm).

[0062] 3. Performance Testing:

[0063] 3.1 Tensile strength: 705 MPa (room temperature); High-temperature creep strength (750℃ / 1000h): 255 MPa;

[0064] 3.2 Corrosion rate (NaCl-KCl molten salt, 90 days): 0.07 mm / y;

[0065] 3.3 Intergranular corrosion (ASTM G28): No cracks, ZrO2 nanoparticles are dispersed at grain boundaries.

[0066] Example 2

[0067] 1. Corrosion-resistant nickel-based alloy welding wire, comprising the following components by weight percentage:

[0068] Nickel (Ni) 52g, Chromium (Cr) 22g, Molybdenum (Mo) 10g, Niobium + Tantalum (Nb + Ta) 3.5g, Copper (Cu) 3g, Tungsten (W) 4g, Rare Earth Elements (Ce / La=1:1) 0.3g, Tellurium (Te) 0.5g, Nano-reinforcing Phase (VC + CeB6) 4g, Fe balance 0.7g.

[0069] 2. Process optimization:

[0070] After electroslag remelting, vacuum consumable refining is added (impurity S / P content ≤0.004% / 0.006% respectively).

[0071] The outer layer of the gradient coating was changed to a CeB6-doped Ni-Cr-Mo layer (0.5μm) to improve high-temperature oxidation resistance.

[0072] 3. Performance data:

[0073] 3.1 Tensile strength: 690 MPa, elongation: 38%;

[0074] 3.2 High-temperature creep rate (750℃ / 200MPa): 1.2×10 -8 / s;

[0075] 3.3 Molten salt corrosion rate: 0.05 mm / y (better than Example 1, because Te-Cu eutectic inhibits grain boundary segregation).

[0076] Example 3

[0077] 1. Ingredient Design:

[0078] Nickel (Ni) 61g, Chromium (Cr) 16g, Molybdenum (Mo) 9.5g, Niobium + Tantalum (Nb + Ta) 3.5g, Copper (Cu) 4.0g, Tungsten (W) 3g, Rare Earth Elements (Ce / La=1:1) 0.3g, Zirconium (Zr) 0.2g, Nano-reinforcing Phase (TiC + BN) 2g, Fe balance 0.5g.

[0079] 2. Technological characteristics:

[0080] After cold drawing, hydrogen stripping treatment (1050℃, H2 / Ar mixed gas) is added to refine the grains to 8μm;

[0081] The surface coating is a Ni-Cr-Mo-CeO2 composite layer (1.2 μm thick) deposited by magnetron sputtering.

[0082] 3. Performance Verification:

[0083] 3.1 Tensile strength: 680MPa, impact toughness (-50℃): 85J;

[0084] 3.2. High-temperature oxidation weight gain (800℃ / 500h): 1.3mg / cm³ 2 (Traditional welding wire ≥3.5mg / cm) 2 );

[0085] 3.3. Sulfur-to-phosphorus ratio control (S / P=0.55): No sulfide segregation at grain boundaries.

[0086] Comparative Example 1 (No nano-reinforced phase + conventional coating)

[0087] 1. Composition adjustment: The nano-reinforcing phase is removed, the grain boundary optimizer contains only 0.2g of Zr, and the coating is a single Ni-Cr layer (1.0μm).

[0088] 2. Performance Comparison:

[0089] 2.1 Tensile strength: 620MPa (decreased by 12%), high temperature creep strength: 180MPa (decreased by 30%).

[0090] 2.2 Corrosion rate: 0.15 mm / y (significant deterioration);

[0091] 2.3 Microscopic defects: SEM showed that the grain boundary carbide segregation and the absence of nanophase led to crack propagation.

[0092] Comparative Example 2 (Prior technology: Inconel 625 welding wire)

[0093] 1. Composition reference: Ni≥58g, Cr 20-23g, Mo 8-10g, Nb 3.15-4.15g, Fe≤5g (no rare earth, grain boundary optimizer and gradient coating).

[0094] 2. Performance differences:

[0095] 2.1 Tensile strength: 650MPa, creep strength at 750℃: 200MPa (25% lower than in Example 1);

[0096] 2.2 Molten salt corrosion rate: 0.12 mm / y (71% higher than in Example 1);

[0097] 2.3 Intergranular corrosion susceptibility: Microcracks were observed in the ASTM G28 test (due to the lack of Ce / La clean grain boundaries).

[0098] The performance comparison analysis of Examples 1, 2, and 3 with Comparative Examples 1 and 2 is shown in Tables 1 and 2.

[0099] Table 1: Comparison of Composition and Process Parameters

[0100]

[0101] Table 2: Comparison of Mechanical and Corrosion Properties

[0102]

[0103] This welding wire, through the synergistic design of optimized composition (e.g., Cr / (Mo+W) = 2.5-3.5), nano-reinforcing phases (BN, CeB6, etc.), and gradient coating (Ni-Cr-Mo / TiC), significantly outperforms traditional technologies (such as Inconel 625) in tensile strength (≥680MPa), corrosion resistance (molten salt corrosion rate ≤0.08mm / y), and yield (≥96%). Comparative studies verify the necessity of nano-reinforcing phases and grain boundary optimization; existing technologies, due to their single composition and process limitations, are unable to meet the requirements of extreme working conditions.

[0104] This invention is not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this invention is limited only by the appended claims.

Claims

1. A corrosion resistant nickel-base alloy welding wire, characterized by, The welding wire comprises the following ingredients in percentage by mass: Nickel: 50-58%, chromium: 16-24%, molybdenum: 8-10%, niobium + tantalum: 3.5-5.5%, copper: 3-4.5%, tungsten: 3-4%, tin: 0.5-1.0%, rare earth elements: 0.1-0.3%, grain boundary optimization agent: 0.1-0.5%, nano-enhanced phase: 2-5%, and the balance being Fe and other inevitable impurities; The rare earth elements are a mixture of cerium and lanthanum, and the mass ratio of cerium to lanthanum is 1:1; The mass ratio of tin to copper is 1:3-1:5, for inhibiting high-temperature fusion welding cracks; The nano-enhanced phase comprises at least one of boron nitride nanosheet, cerium hexaboride, titanium carbide, vanadium carbide or nickel-coated cerium oxide nanocapsule, and the particle size of the nano-enhanced phase is 20-50nm; The grain boundary optimization agent comprises at least one of zirconium and tellurium, for inhibiting intergranular corrosion and carbide segregation; The surface of the welding wire is coated with a gradient plating layer, the gradient plating layer comprises an inner layer and an outer layer, the inner layer is a nanometer Ni-Cr-Mo alloy layer with a thickness of 0.5-1.5μm, and the outer layer is a TiC ceramic layer or a CeB6-doped Ni-Cr-Mo layer.

2. The corrosion resistant nickel-base alloy welding wire of claim 1, wherein, The atomic percentage of chromium, molybdenum and tungsten satisfies Cr / (Mo+W) = 2.5-3.

5.

3. The corrosion resistant nickel-base alloy welding wire of claim 1, wherein, The tensile strength of the welding wire is ≥680MPa, the high-temperature stress-rupture strength at 750℃ is ≥240MPa, and the corrosion rate in molten salt environment is ≤0.08mm / y.

4. The corrosion resistant nickel-base alloy welding wire of claim 1, wherein, The impurity control is: sulfur ≤0.005%, phosphorus ≤0.008%, iron content ≤7%, and the mass ratio of sulfur to phosphorus ≤0.6.

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