Welding method for high-temperature alloy dissimilar materials for gas turbine

Abstract

The invention relates to the technical field of alloy dissimilar materials, in particular to a high-temperature alloy dissimilar material welding method for a gas turbine, which comprises the following steps: S1, mechanically grinding and polishing the to-be-welded surfaces of an alloy dissimilar material A and an alloy dissimilar material B, and then ultrasonically cleaning and drying for later use; s2, preparing a modified molybdenum-based composite layer; s3, a sample is cooled in vacuum, then high-purity argon is introduced, the sample is taken out and assembled with the alloy dissimilar material B obtained in the step S1 in a butt joint mode, and modified brazing filler metal powder is placed; and S4, the sample in the step S2 is placed in a vacuum brazing furnace, vacuumizing is conducted, the temperature is slowly increased to 1300 DEG C, heat preservation is conducted, the temperature is slowly decreased to the room temperature in a furnace cooling mode, and then welding is completed. The wettability of the brazing filler metal to base metal is remarkably improved, diffusion and solid solution among elements are promoted, and the tensile strength of a joint is remarkably improved. And meanwhile, a vacuum brazing process is adopted, and precise temperature and time control is matched, so that oxidation and pollution are avoided, and the stability and repeatability of welding quality are ensured.

Description

A method for welding dissimilar high-temperature alloy materials for gas turbines Technical Field

[0001] This invention relates to the field of dissimilar alloy materials technology, specifically a welding method for high-temperature dissimilar alloy materials used in gas turbines. Background Technology

[0002] As gas turbines serve as highly efficient energy conversion devices, their core components often operate in high-temperature, high-pressure, and corrosive environments. Therefore, nickel-based and cobalt-based high-temperature alloys such as Haynes 188, Haynes X-750, and Stellite 694 are widely used. In actual manufacturing, different types of high-temperature alloys often need to be welded together to meet structural and functional requirements. Among these, Haynes X-750 and Hastelloy X (HAST-X) are typical dissimilar high-temperature alloy combinations and have important applications in high-temperature components of gas turbines.

[0003] However, due to differences in chemical composition, physical properties, and coefficient of thermal expansion between Haynes X-750 and Hastelloy X, direct welding is prone to defects such as cracks, porosity, and lack of fusion. The high-temperature strength, oxidation resistance, and durability of the welded joint are insufficient to meet long-term service requirements. While traditional brazing methods can achieve a connection to some extent, poor wettability between the filler metal and the base metal and insufficient element diffusion result in low joint strength and insufficient reliability.

[0004] Therefore, developing a welding method suitable for high-temperature alloy dissimilar materials used in gas turbines to improve the high-temperature performance and structural stability of the joint has become an urgent technical challenge in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method for welding dissimilar high-temperature alloy materials for gas turbines.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for welding dissimilar high-temperature alloy materials for gas turbines, comprising the following steps: S1. Mechanically grinding and polishing the surfaces of dissimilar alloy materials A and B to be welded, followed by ultrasonic cleaning with acetone and ethanol to remove oil and oxide layers, and drying for later use; S2. Preparation of a modified molybdenum-based composite layer: S21. Placing the dissimilar alloy material A obtained in step S1 in an ion sputtering device, under a vacuum degree ≤5×10 -4S22. High-purity argon and silane gas are introduced into the cavity under pressure S2. The molybdenum-titanium-chromium ternary alloy target power supply is turned on, and the sputtering power is set to 300-400W, the substrate bias voltage is -80V, the temperature is controlled at 300-400℃, and the sputtering time is 100-120min to obtain a sample after sputtering the modified molybdenum-based composite layer; S3. The sample obtained in step S2 is cooled to 100-150℃ under vacuum, then filled with high-purity argon gas to break the vacuum, and then taken out and butt-fitted with the dissimilar alloy material B obtained in step S1, and the modified brazing filler powder is evenly placed at the joint gap of 0.05-0.10mm; S4. The sample in step S3 is placed in a vacuum brazing furnace and evacuated to ≤5×10 -3 Pa, slowly heat to 1300℃, hold for 10-15 minutes, and then slowly cool to room temperature by furnace cooling to complete the welding.

[0007] Preferably, the preparation of modified solder powder includes the following steps: S31. Add the mixed metal powder to a three-dimensional mixer and mix under argon protection for 4-6 hours to obtain uniform metal powder; S32. Add calcium fluoride to the uniform metal powder obtained in step S31, continue mixing under argon protection for 40-50 minutes, vacuum dry, and pass through a 200-mesh sieve to obtain modified solder powder.

[0008] Preferably, the silane gas is selected from methanesilane.

[0009] Preferably, in step S2, the argon gas flow rate in the ion sputtering equipment is 30 sccm, the silane gas flow rate is controlled at 1-3 sccm, and the gas pressure is 0.4 Pa.

[0010] Preferably, the sputtering deposition thickness in step S22 is 2-5 μm.

[0011] Preferably, the heating rate in step S4 is 10-15℃ / min.

[0012] Preferably, the mixed metal powder is composed of molybdenum, nickel, chromium, titanium and tungsten in a mass ratio of 51:45:3:0.5:0.5.

[0013] Preferably, the mass ratio of calcium fluoride to the uniform metal powder obtained in step S31 is 1:500.

[0014] Preferably, the dissimilar alloy material A is selected from molybdenum-free nickel-chromium alloys.

[0015] Preferably, the dissimilar alloy material B is selected from molybdenum-containing nickel-chromium alloys.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention significantly improves the wettability of the brazing filler metal to the base material, promotes the diffusion and solid solution between elements, and significantly improves the tensile strength of the joint. At the same time, the use of vacuum brazing process, combined with precise temperature and time control, avoids oxidation and contamination, ensuring the stability and repeatability of welding quality.

[0017] 2. This invention, through the synergistic effect of the modified molybdenum-based composite layer and modified solder powder, not only thoroughly purifies the joint interface but also forms a stronger metallurgical bonding layer. This lays a high-strength, low-defect interface foundation for the entire joint, ensuring the uniformity and consistency of joint performance. Simultaneously, it effectively absorbs and disperses the thermal and structural stresses generated during welding and service, greatly suppressing the risk of crack initiation and propagation, and significantly extending the service life of the components. Attached Figure Description

[0018] Figure 1 is a flowchart of the welding process for the high-temperature alloy dissimilar material for gas turbines of the present invention; Figure 2 is a flowchart of the preparation process for the modified brazing filler metal powder of the present invention; Figure 3 is a schematic diagram of the welded joint structure of the high-temperature alloy dissimilar material for gas turbines obtained in Example 1 of the present invention; Figure 4 is a schematic diagram of the welded joint structure of the high-temperature alloy dissimilar material for gas turbines obtained in Example 2 of the present invention; Figure 5 is a schematic diagram of the welded joint structure of the high-temperature alloy dissimilar material for gas turbines obtained in Example 3 of the present invention; Figure 6 is a schematic diagram of the welded joint structure of the high-temperature alloy dissimilar material for gas turbines obtained in Example 4 of the present invention; Figure 7 is a schematic diagram of the welded joint structure of the high-temperature alloy dissimilar material for gas turbines obtained in Comparative Example 1 of the present invention; Figure 8 is a schematic diagram of the welded joint structure of the high-temperature alloy dissimilar material for gas turbines obtained in Comparative Example 2 of the present invention. Detailed Implementation

[0019] The present invention will now be clearly and completely described in conjunction with embodiments thereof. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] Please refer to Figures 1-8. This invention provides a technical solution: Haynes X-750 (UNS N07750) is a nickel-chromium-based precipitation-hardening superalloy, which has become a core material in the aerospace, energy, and chemical industries due to its excellent high-temperature strength, oxidation resistance, and corrosion resistance. The main components are: Nickel (Ni, ≥70%): providing an austenitic matrix and high-temperature stability; Chromium (Cr, 14%-17%): enhancing oxidation resistance and resisting sulfide / chloride corrosion; Aluminum (Al, 0.4%-1.0%) + Titanium (Ti, 2.25%-2.75%): forming the γ' phase (Ni3Al / Ti) to achieve precipitation strengthening. Auxiliary elements: Iron (Fe≤7%) and Niobium (Nb≤1%) optimize thermal strength, and Carbon (C≤0.08%) control grain boundary precipitation.

[0021] Hastelloy X (also known as HAST-X) is a high-performance nickel-based alloy renowned for its excellent high-temperature oxidation resistance, structural stability, and superior corrosion resistance in various atmospheres. Designed for operation in extreme thermal environments, this alloy is particularly suitable for various industrial furnace systems and is a key material choice for industries such as aerospace, energy, heat treatment, and high-temperature chemicals. The chemical composition of Hastelloy X is primarily composed of nickel, chromium, iron, and molybdenum. This balanced alloy design endows the material with excellent corrosion resistance in oxidizing, reducing, and neutral atmospheres. It performs exceptionally well in high-temperature furnace applications. For example, at a high temperature of 2150℉ (approximately 1177℃), Hastelloy X furnace rollers maintained good structural and functional condition after 8700 hours of continuous operation, demonstrating excellent thermal stability and durability.

[0022] Ion sputtering of metallic molybdenum facilitates the formation of a dense molybdenum layer on the surface of X-750 material, corresponding to the molybdenum in Hast-X material, thus reducing the differences between the two materials. The main components of the solder are Mo, Ni, and Cr, which better integrate with the Ni and Cr in the base material. To increase the wetting of X-750 and Hast-X by the solder, a small amount of Ti is added to the solder to promote wetting of the solder in the base material. Considering the effect of Mo on the base material surface, W is added to the solder; W and Mo can directly form a solid solution, increasing the strength of the brazed joint.

[0023] Example 1: A method for welding dissimilar high-temperature alloy materials for gas turbines: Before welding, modified brazing filler powder is prepared. The preparation of modified brazing filler powder includes the following steps: S31. Mixed metal powder (composed of molybdenum, nickel, chromium, titanium, and tungsten in a mass ratio of 51:45:3:0.5:0.5) is added to a three-dimensional mixer and mixed for 4 hours under argon protection to obtain uniform metal powder; S32. Calcium fluoride (in a mass ratio of 500:1) is added to the uniform metal powder obtained in step S31, and the mixture is continued to be mixed for 40 minutes under argon protection. After vacuum drying, it is passed through a 200-mesh sieve to obtain modified brazing filler powder.

[0024] S1. Mechanically grind and polish the surfaces of Haynes X-750 and Hastelloy X to be soldered, then ultrasonically clean them with acetone and ethanol to remove oil and oxide layers, and dry them for later use; S2. Preparation of the modified molybdenum-based composite layer: S21. Place the Haynes X-750 obtained in step S1 in an ion sputtering apparatus, and heat it under a vacuum of 5×10⁻⁶. -4 S22. High-purity argon and silane gas (silane, argon flow rate 30 sccm, silane flow rate precisely controlled at 1 sccm, pressure 0.4 Pa) are introduced into the cavity. S3. High-purity argon and silane gas (silane, argon flow rate 30 sccm, silane flow rate precisely controlled at 1 sccm, pressure 0.4 Pa) are introduced into the cavity. S4. The molybdenum-titanium-chromium ternary alloy target power supply is turned on, the sputtering power is set to 300 W, the substrate bias voltage is -80 V, the temperature is controlled at 300 °C, the sputtering time is 100 min, and the deposition thickness is 2 μm, to obtain the sample after sputtering the modified molybdenum-based composite layer. S5. The sample obtained in step S2 is cooled to 100 °C under vacuum, then high-purity argon gas is introduced to break the vacuum, and the sample is taken out and assembled with the Hastelloy X obtained in step S1. Modified brazing powder is evenly placed at the joint gap of 0.05 mm. S6. The sample in step S3 is placed in a vacuum brazing furnace and evacuated to 5 × 10⁻⁶ Pa. -3 The temperature is increased to 1300℃ at a rate of 10℃ / min, held for 10min, and then slowly cooled to room temperature by furnace cooling to complete the welding.

[0025] Example 2: A method for welding dissimilar high-temperature alloy materials for gas turbines: Before welding, modified brazing filler powder is prepared. The preparation of modified brazing filler powder includes the following steps: S31. Mixed metal powder (composed of molybdenum, nickel, chromium, titanium, and tungsten in a mass ratio of 51:45:3:0.5:0.5) is added to a three-dimensional mixer and mixed for 6 hours under argon protection to obtain uniform metal powder; S32. Calcium fluoride (in a mass ratio of 500:1) is added to the uniform metal powder obtained in step S31, and the mixture is continued to be mixed for 50 minutes under argon protection. After vacuum drying, it is passed through a 200-mesh sieve to obtain modified brazing filler powder.

[0026] S1. Mechanically grind and polish the surfaces of Haynes X-750 and Hastelloy X to be soldered, then ultrasonically clean them with acetone and ethanol to remove oil and oxide layers, and dry them for later use; S2. Preparation of the modified molybdenum-based composite layer: S21. Place the Haynes X-750 obtained in step S1 in an ion sputtering apparatus, and heat it under a vacuum of 5×10⁻⁶. -4 S22. High-purity argon and silane gas (silane, argon flow rate 30 sccm, silane flow rate precisely controlled at 3 sccm, pressure 0.4 Pa) are introduced into the cavity. S3. High-purity argon and silane gas (silane, argon flow rate 30 sccm, silane flow rate precisely controlled at 3 sccm, pressure 0.4 Pa) are introduced into the cavity. S4. The molybdenum-titanium-chromium ternary alloy target power supply is turned on, the sputtering power is set to 400 W, the substrate bias voltage is -80 V, the temperature is controlled at 400 °C, the sputtering time is 120 min, and the deposition thickness is 5 μm, to obtain the sample after sputtering the modified molybdenum-based composite layer. S5. The sample obtained in step S2 is cooled to 150 °C under vacuum, then high-purity argon gas is introduced to break the vacuum, and the sample is taken out and assembled with the Hastelloy X obtained in step S1. Modified brazing filler powder is evenly placed 0.10 mm at the joint gap. S6. The sample obtained in step S3 is placed in a vacuum brazing furnace and evacuated to 5 × 10⁻⁶ Pa. -3 Pa, heat to 1300℃ at a rate of 15℃ / min, hold for 15min, and then slowly cool to room temperature by furnace cooling to complete the welding.

[0027] Example 3: A method for welding dissimilar high-temperature alloy materials for gas turbines: Before welding, modified brazing filler powder is prepared. The preparation of modified brazing filler powder includes the following steps: S31. Mixed metal powder (composed of molybdenum, nickel, chromium, titanium, and tungsten in a mass ratio of 51:45:3:0.5:0.5) is added to a three-dimensional mixer and mixed for 5 hours under argon protection to obtain uniform metal powder; S32. Calcium fluoride (in a mass ratio of 500:1) is added to the uniform metal powder obtained in step S31, and the mixture is continued to be mixed for 42 minutes under argon protection. After vacuum drying, it is passed through a 200-mesh sieve to obtain modified brazing filler powder.

[0028] S1. Mechanically grind and polish the surfaces of Haynes X-750 and Hastelloy X to be soldered, then ultrasonically clean them with acetone and ethanol to remove oil and oxide layers, and dry them for later use; S2. Preparation of the modified molybdenum-based composite layer: S21. Place the Haynes X-750 obtained in step S1 in an ion sputtering apparatus, and heat it under a vacuum of 4×10⁻⁶. -4S22. High-purity argon and silane gas (silane, argon flow rate 30 sccm, silane flow rate precisely controlled at 2 sccm, pressure 0.4 Pa) are introduced into the cavity. S3. High-purity argon and silane gas (silane, argon flow rate 30 sccm, silane flow rate precisely controlled at 2 sccm, pressure 0.4 Pa) are introduced into the cavity. S4. The molybdenum-titanium-chromium ternary alloy target power supply is turned on, the sputtering power is set to 350 W, the substrate bias voltage is -80 V, the temperature is controlled at 320 °C, the sputtering time is 105 min, and the deposition thickness is 3 μm, to obtain the sample after sputtering the modified molybdenum-based composite layer. S5. The sample obtained in step S2 is cooled to 120 °C under vacuum, then high-purity argon gas is introduced to break the vacuum, and the sample is taken out and assembled with the Hastelloy X obtained in step S1. Modified brazing powder is evenly placed at the joint gap of 0.06 mm. S6. The sample obtained in step S3 is placed in a vacuum brazing furnace and evacuated to 4 × 10⁻⁶ Pa. -3 The temperature was increased to 1300℃ at a rate of 11℃ / min, held for 11 minutes, and then slowly cooled to room temperature by furnace cooling to complete the welding.

[0029] Example 4: A method for welding dissimilar high-temperature alloy materials for gas turbines: Before welding, modified brazing filler powder is prepared. The preparation of modified brazing filler powder includes the following steps: S31. Mixed metal powder (composed of molybdenum, nickel, chromium, titanium, and tungsten in a mass ratio of 51:45:3:0.5:0.5) is added to a three-dimensional mixer and mixed for 5 hours under argon protection to obtain uniform metal powder; S32. Calcium fluoride (in a mass ratio of 500:1) is added to the uniform metal powder obtained in step S31, and the mixture is continued to be mixed for 48 minutes under argon protection. After vacuum drying, it is passed through a 200-mesh sieve to obtain modified brazing filler powder.

[0030] S1. Mechanically grind and polish the surfaces of Haynes X-750 and Hastelloy X to be soldered, then ultrasonically clean them with acetone and ethanol to remove oil and oxide layers, and dry them for later use; S2. Preparation of the modified molybdenum-based composite layer: S21. Place the Haynes X-750 obtained in step S1 in an ion sputtering apparatus, and heat it under a vacuum of 4×10⁻⁶. -4 S22. High-purity argon and silane gas (silane, argon flow rate 30 sccm, silane flow rate precisely controlled at 2 sccm, pressure 0.4 Pa) are introduced into the cavity. S3. High-purity argon and silane gas (silane, argon flow rate 30 sccm, silane flow rate precisely controlled at 2 sccm, pressure 0.4 Pa) are introduced into the cavity. S4. The molybdenum-titanium-chromium ternary alloy target power supply is turned on, the sputtering power is set to 360 W, the substrate bias voltage is -80 V, the temperature is controlled at 360 °C, the sputtering time is 110 min, and the deposition thickness is 4 μm, to obtain the sample after sputtering the modified molybdenum-based composite layer. S5. The sample obtained in step S2 is cooled to 140 °C under vacuum, then high-purity argon gas is introduced to break the vacuum, and the sample is taken out and assembled with the Hastelloy X obtained in step S1. Modified brazing powder is evenly placed at the joint gap of 0.08 mm. S6. The sample in step S3 is placed in a vacuum brazing furnace and evacuated to 4 × 10⁻⁶ Pa.-3 The temperature is increased to 1300℃ at a rate of 14℃ / min, held for 14min, and then slowly cooled to room temperature by furnace cooling to complete the welding.

[0031] Comparative Example 1 differs from Example 1 in that no modified molybdenum-based composite layer was added in this comparative example, while the remaining steps are exactly the same in Comparative Example 1 and Example 1.

[0032] Comparative Example 2 differs from Example 1 in that the modified solder powder is replaced with the base solder (Mo-45Ni-3Cr) in this comparative example. The remaining steps are exactly the same in Comparative Example 2 and Example 1.

[0033] Performance Testing: Figures 3-8 are schematic diagrams of the microstructure of welded joints of dissimilar high-temperature alloy materials for gas turbines obtained in Examples 1-4 and Comparative Examples 1-2 of this invention. It is clearly shown from the figures that the welded joint microstructure of the dissimilar high-temperature alloy materials for gas turbines obtained in Examples 1-4 is more uniform and dense, with a clear interface and good bonding between the weld area and the base material, and no obvious cracks, porosity, or lack of fusion. In Comparative Examples 1-2, microcracks are locally visible in the welded joint microstructure of the dissimilar high-temperature alloy materials for gas turbines, and the interface bonding is weaker.

[0034] According to GB / T 11364-2008 "Test Method for Spreadability and Sealing Properties of Brazing Alloy" and GB / T 2039-2012 "Metallic Materials - Uniaxial Tensile Creep Test Method", the brazing alloy spread area and high-temperature creep strength of the dissimilar high-temperature alloy materials for gas turbines obtained in Examples 1-4 and Comparative Examples 1-2 were tested. The data obtained are shown in Table 1 below: Table 1 Brazing Alloy Spread Area and High-Temperature Creep Strength Test Results As shown in Table 1, the spread area of ​​the high-temperature alloy dissimilar materials for gas turbines obtained in Examples 1-4 is significantly larger than that of all comparative examples, especially about 70% higher than that of Comparative Example 1. This directly proves that the activity of the modified brazing filler metal powder and the modified molybdenum-based composite layer produces excellent synergistic film removal and wetting effects. Under the harsh conditions of high temperature and high pressure, the high-temperature alloy dissimilar materials for gas turbines obtained in Examples 1-4 are superior to the comparative examples in terms of compressive strength and creep rupture life. The synergistic effect of the modified molybdenum-based composite layer and the modified brazing filler metal powder provides an excellent high-temperature oxidation barrier; the good interfacial bonding and gradient structure effectively inhibit the nucleation and connection of creep voids at the interface; and the reinforcing phase inside the brazing seam ensures the overall creep resistance.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for welding dissimilar high-temperature alloy materials for gas turbines, characterized in that, Includes the following steps: S1. Mechanically grind and polish the surfaces of dissimilar alloy materials A and B to be welded, then ultrasonically clean them with acetone and ethanol to remove oil and oxide layers, and dry them for later use; S2. Preparation of the modified molybdenum-based composite layer: S21. Place the dissimilar alloy material A obtained in step S1 in an ion sputtering device, and heat it under a vacuum degree ≤5×10 -4 S22. High-purity argon and silane gas are introduced into the cavity under Pa. S3. The molybdenum-titanium-chromium ternary alloy target power supply is turned on, and the sputtering power is set to 300-400W, the substrate bias voltage is -80V, the temperature is controlled at 300-400℃, and the sputtering time is 100-120min to obtain the sample after sputtering the modified molybdenum-based composite layer. S4. The sample obtained in step S2 is cooled to 100-150℃ under vacuum, and then high-purity argon gas is introduced to break the vacuum. After being taken out, it is assembled with the dissimilar alloy material B obtained in step S1, and the modified brazing filler powder is evenly placed at the joint gap of 0.05-0.10mm. S4. Place the sample from step S3 in a vacuum brazing furnace and evacuate it to a vacuum level of ≤5×10⁻⁶. -3 Pa, slowly heat to 1300℃, hold for 10-15 minutes, and then slowly cool to room temperature by furnace cooling to complete the welding.

2. The method for welding dissimilar high-temperature alloy materials for gas turbines according to claim 1, characterized in that, The preparation of the modified solder powder includes the following steps: S31. Add the mixed metal powder to a three-dimensional mixer and mix under argon protection for 4-6 hours to obtain uniform metal powder; S32. Add calcium fluoride to the uniform metal powder obtained in step S31, continue mixing under argon protection for 40-50 minutes, vacuum dry, and pass through a 200-mesh sieve to obtain modified solder powder.

3. The method for welding dissimilar high-temperature alloy materials for gas turbines according to claim 1, characterized in that, The silane gas is selected from methanesilane.

4. The method for welding dissimilar high-temperature alloy materials for gas turbines according to claim 1, characterized in that, In step S2, the argon flow rate in the ion sputtering equipment is 30 sccm, the silane flow rate is controlled between 1-3 sccm, and the pressure is 0.4 Pa.

5. The method for welding dissimilar high-temperature alloy materials for gas turbines according to claim 1, characterized in that, In step S22, the sputtering deposition thickness is 2-5 μm.

6. The method for welding dissimilar high-temperature alloy materials for gas turbines according to claim 1, characterized in that, The heating rate in step S4 is 10-15℃ / min.

7. A method for welding dissimilar high-temperature alloy materials for gas turbines according to claim 2, characterized in that, The mixed metal powder is composed of molybdenum, nickel, chromium, titanium and tungsten in a mass ratio of 51:45:3:0.5:0.

5.

8. A method for welding dissimilar high-temperature alloy materials for gas turbines according to claim 2, characterized in that, The mass ratio of the calcium fluoride to the uniform metal powder obtained in step S31 is 1:

500.

9. A method for welding dissimilar high-temperature alloy materials for gas turbines according to claim 1, characterized in that, The alloy material A is selected from molybdenum-free nickel-chromium alloys.

10. A method for welding dissimilar high-temperature alloy materials for gas turbines according to claim 1, characterized in that, The alloy material B is selected from molybdenum-containing nickel-chromium alloys.

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