Cobalt-based high-temperature alloy brazing filler metal and preparation method and welding method thereof

Abstract

The invention relates to the technical field of high-temperature alloy connection, and provides cobalt-based high-temperature alloy brazing filler metal and a preparation method and a welding method thereof, and the brazing filler metal comprises the following chemical components in percentage by mass: 7-13% of Ni, 10-20% of Cr, 0.01-3% of Ta, 0.01-0.3% of Ti, 8-14% of W, 1-3% of B, 0.01-0.4% of Zr, 0.1-0.5% of C and the balance of Co. According to the cobalt-based high-temperature alloy brazing filler metal, the Ni element is added to stabilize the austenite structure, and the plasticity of a weld joint is improved; in addition, by reducing the content of the Cr element and increasing the content of the W element, the proportion of the Cr element and the W element is changed, so that the obdurability of the weld joint is improved, the strength of the weld joint can be further improved by introducing the Ta element, the Ta element and the C element can form a TaC-phase carbide, in addition, the B element and the C element are adopted as melting reduction elements, and therefore the welding quality of the weld joint is improved. The melting point of the brazing filler metal can be reduced; the wettability of the brazing filler metal is improved.

Description

Technical Field

[0001] The present application relates to the technical field of high-temperature alloy connection, and in particular to a cobalt-based high-temperature alloy brazing filler metal and a preparation method and a welding method thereof. Background Art

[0002] Cobalt-based superalloys are advanced high-temperature structural materials with an austenite matrix and carbide reinforcement. Due to their excellent resistance to oxidative corrosion and high-temperature fatigue, they are widely used in the manufacture of key hot-end components such as guide vanes and fuel nozzles in aircraft engines and heavy-duty gas turbines.

[0003] Due to the combined effects of prolonged high temperatures and alternating mechanical loads, these components are prone to thermal fatigue cracking on their surfaces, posing a serious threat to the operational reliability and service safety of the equipment. Therefore, existing technologies typically use vacuum brazing as a key process for repairing hot-end components. When vacuum brazing is used to repair cracks in cobalt-based superalloys, commercial nickel- or cobalt-based brazing filler metals are primarily used.

[0004] However, commercial nickel-based or cobalt-based brazing filler metals contain high levels of melting-depressing elements and their compositions differ greatly from those of the parent metal, resulting in poor weld performance. Summary of the Invention

[0005] The embodiments of the present application provide a cobalt-based high-temperature alloy brazing filler metal and a preparation method and a welding method thereof, aiming to solve the technical problem that commercial nickel-based or cobalt-based brazing filler metals have a high content of depressant elements and a large difference in composition from the base material, resulting in relatively poor weld performance.

[0006] In a first aspect, an embodiment of the present application provides a cobalt-based high-temperature alloy brazing filler metal, the chemical composition and mass percentage of the brazing filler metal are as follows:

[0007] Ni: 7~13%, Cr: 10~20%, Ta: 0.01~3%, Ti: 0.01~0.3%, W: 8~14%, B: 1~3%, Zr: 0.01~0.4%, C: 0.1~0.5%, and Co is the balance.

[0008] In some possible implementations, Ta: 1.5-2.5%, Ti: 0.1-0.2%.

[0009] In some possible implementations, Cr: 14-18%, W: 10-12%.

[0010] In some possible implementations, B: 2-3%, C: 0.3-0.5%.

[0011] In some possible implementations, the solder is provided in a spherical or nearly spherical powder form.

[0012] In a second aspect, an embodiment of the present application provides a method for preparing a cobalt-based high-temperature alloy brazing filler metal, which is applied to any of the above-mentioned cobalt-based high-temperature alloy brazing filler metals, and the preparation method comprises:

[0013] S1: melting and preparing the solder according to the composition of the solder, and melting it in a vacuum induction furnace to obtain a master alloy ingot;

[0014] S2: crushing the master alloy ingot into powder by gas atomization under inert gas protection to obtain alloy powder;

[0015] S3: The alloy powder is sieved and powder with a particle size of -200 mesh is selected as the final cobalt-based high-temperature alloy brazing material.

[0016] In some possible embodiments, the process parameters of the vacuum induction melting are: melting temperature of 1350-1450°C, vacuum degree of less than 5×10 -1 Pa, refining time 5 to 20 minutes.

[0017] In some possible implementations, the process parameters of the gas atomization method are: melting temperature 1450-1550° C., melting time 5-15 min, powder spraying gas is argon, and the mass flow rate is 2-5 kg / min.

[0018] In a third aspect, an embodiment of the present application provides a method for welding a cobalt-based high-temperature alloy brazing filler metal, which is applied to any of the above-mentioned cobalt-based high-temperature alloy brazing filler metals, and the welding method comprises:

[0019] S1: Grind the surface of the substrate to be welded to remove the surface oxide layer and impurities, exposing the surface to be welded with a metallic luster.

[0020] S2: The solder powder and the oily binder are uniformly mixed in proportion to obtain a paste solder, wherein the amount of the binder added is 10% of the mass of the powder.

[0021] S3: evenly coating the solder paste on the surface to be soldered, and placing the substrate coated with the solder paste in an oven, and drying at 100-140° C. for 1 hour.

[0022] S4: placing the dried substrate coated with the paste solder into a vacuum brazing furnace for high-temperature brazing.

[0023] In some possible implementations, the welding parameters of the vacuum brazing furnace are as follows: the weld gap is 100 μm, the welding temperature is 1180-1240°C, the holding time is 0.5-4 hours, and the vacuum degree in the furnace is not higher than 1×10 -2 Pa.

[0024] The present embodiment provides a cobalt-based high-temperature alloy brazing filler metal, wherein the chemical composition and mass percentage of the brazing filler metal are as follows: Ni: 7-13%, Cr: 10-20%, Ta: 0.01-3%, Ti: 0.01-0.3%, W: 8-14%, B: 1-3%, Zr: 0.01-0.4%, C: 0.1-0.5%, and Co as the balance.

[0025] In terms of strengthening elements, this embodiment not only stabilizes the austenite structure and improves the plasticity of the weld by adding Ni, but also reduces the Cr content and increases the W content, thereby changing the ratio of Cr to W, thereby improving the strength and toughness of the weld. In addition, this embodiment also introduces Ta element. Since Ta element can form TaC phase carbide with C element, the weld strength can be further improved. In addition, by using B element and C element as melting point depressing elements, the melting point of the solder can be lowered and the wettability of the solder can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0028] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0029] Figure 1 This is a schematic diagram of the powder solder morphology in Example 1 provided in this application.

[0030] Figure 2 This is a schematic diagram of the DSC test results of the powder solder in Example 1 provided in this application.

[0031] Figure 3 This is a schematic diagram of the weld microstructure in Example 1 provided in this application.

[0032] Figure 4 This is a schematic diagram of the tensile properties at 870°C after welding in Example 1 provided in this application.

[0033] Figure 5This is a schematic diagram of the fracture position of the welding sample in Example 1 provided in this application.

[0034] Figure 6 This is a schematic diagram of the DSC test results of the weld joint in Example 1 provided in this application.

[0035] Figure 7 Schematic diagram of the microstructure of the weld joint in Comparative Example 1 provided in this application.

[0036] Figure 8 This is a schematic diagram of the tensile properties at 870°C after welding in Comparative Example 1 provided in this application.

[0037] Figure 9 Schematic diagram of the fracture position of the welding sample in Comparative Example 1 provided in this application. DETAILED DESCRIPTION

[0038] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0039] The disclosure below provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, these are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0040] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0041] It should also be understood that the terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the present application. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0042] It should be further understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0043] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0044] Cobalt-based superalloys are advanced high-temperature structural materials with an austenite matrix and carbide reinforcement. Due to their excellent resistance to oxidative corrosion and high-temperature fatigue, they are widely used in the manufacture of key hot-end components such as guide vanes and fuel nozzles in aircraft engines and heavy-duty gas turbines.

[0045] Due to the combined effects of prolonged high temperatures and alternating mechanical loads, these components are prone to thermal fatigue cracking on their surfaces, posing a serious threat to the operational reliability and service safety of the equipment. Therefore, existing technologies typically use vacuum brazing as a key process for repairing hot-end components. When vacuum brazing is used to repair cracks in cobalt-based superalloys, commercial nickel- or cobalt-based brazing filler metals are primarily used.

[0046] However, commercial nickel-based or cobalt-based brazing filler metals contain high levels of melting-depressing elements and their compositions differ greatly from those of the parent metal, resulting in poor weld performance.

[0047] In order to solve the technical problem in the existing technology that the commercial nickel-based or cobalt-based brazing filler metals have a high content of depressant elements and a large difference in composition from the base material, resulting in poor weld performance, the present application provides a cobalt-based high-temperature alloy brazing filler metal that can improve the toughness and strength of the weld.

[0048] The present invention provides a cobalt-based high-temperature alloy brazing filler metal. The chemical composition and mass percentage of the brazing filler metal are as follows:

[0049] Ni: 7~13%, Cr: 10~20%, Ta: 0.01~3%, Ti: 0.01~0.3%, W: 8~14%, B: 1~3%, Zr: 0.01~0.4%, C: 0.1~0.5%, and Co is the balance.

[0050] In terms of strengthening elements, this embodiment not only stabilizes the austenite structure and improves the plasticity of the weld by adding Ni, but also reduces the Cr content and increases the W content, thereby changing the ratio of Cr to W, thereby improving the strength and toughness of the weld. In addition, this embodiment also introduces Ta element. Since Ta element can form TaC phase carbide with C element, the weld strength can be further improved. In addition, by using B element and C element as melting point depressing elements, the melting point of the solder can be lowered and the wettability of the solder can be improved.

[0051] In some possible implementations, Ta: 1.5-2.5%, Ti: 0.1-0.2%.

[0052] For example, the chemical composition and mass percentage of the solder may be:

[0053] Ni: 7-13%, Cr: 10-20%, Ta: 1.5-2.5%, Ti: 0.1-0.2%, W: 8-14%, B: 1-3%, Zr: 0.01-0.4%, C: 0.1-0.5%, and Co is the balance.

[0054] In some possible implementations, Cr: 14-18%, W: 10-12%.

[0055] For example, the chemical composition and mass percentage of the solder may be:

[0056] Ni: 7~13%, Cr: 14~18%, Ta: 0.01~3%, Ti: 0.01~0.3%, W: 10~12%, B: 1~3%, Zr: 0.01~0.4%, C: 0.1~0.5%, and Co is the balance.

[0057] Alternatively, in other embodiments, the chemical composition and mass percentage of the solder may be:

[0058] Ni: 7~13%, Cr: 14~18%, Ta: 1.5~2.5%, Ti: 0.1~0.2%, W: 10~12%, B: 1~3%, Zr: 0.01~0.4%, C: 0.1~0.5%, and Co is the balance.

[0059] In some possible implementations, B: 2-3%, C: 0.3-0.5%.

[0060] For example, the chemical composition and mass percentage of the solder may be:

[0061] Ni: 7~13%, Cr: 10~20%, Ta: 0.01~3%, Ti: 0.01~0.3%, W: 8~14%, B: 2~3%, Zr: 0.01~0.4%, C: 0.3~0.5%, and Co is the balance.

[0062] Alternatively, in other embodiments, the chemical composition and mass percentage of the solder may be:

[0063] Ni: 7-13%, Cr: 10-20%, Ta: 1.5-2.5%, Ti: 0.1-0.2%, W: 8-14%, B: 2-3%, Zr: 0.01-0.4%, C: 0.3-0.5%, and Co is the balance.

[0064] Alternatively, in other embodiments, the chemical composition and mass percentage of the solder may be:

[0065] Ni: 7~13%, Cr: 14~18%, Ta: 0.01~3%, Ti: 0.01~0.3%, W: 10~12%, B: 2~3%, Zr: 0.01~0.4%, C: 0.3~0.5%, and Co is the balance.

[0066] Alternatively, in other embodiments, the chemical composition and mass percentage of the solder may be:

[0067] Ni: 7~13%, Cr: 14~18%, Ta: 1.5~2.5%, Ti: 0.1~0.2%, W: 10~12%, B: 2~3%, Zr: 0.01~0.4%, C: 0.3~0.5%, and Co is the balance.

[0068] In some possible implementations, Ni: 9-11%, Zr: 0.1-0.3%.

[0069] For example, the chemical composition and mass percentage of the solder may be:

[0070] Ni: 9-11%, Cr: 10-20%, Ta: 0.01-3%, Ti: 0.01-0.3%, W: 8-14%, B: 1-3%, Zr: 0.1-0.3%, C: 0.1-0.5%, and Co is the balance.

[0071] Alternatively, in other embodiments, the chemical composition and mass percentage of the solder may be:

[0072] Ni: 9-11%, Cr: 10-20%, Ta: 1.5-2.5%, Ti: 0.1-0.2%, W: 8-14%, B: 1-3%, Zr: 0.1-0.3%, C: 0.1-0.5%, and Co is the balance.

[0073] Alternatively, in other embodiments, the chemical composition and mass percentage of the solder may be:

[0074] Ni: 9~11%, Cr: 14~18%, Ta: 0.01~3%, Ti: 0.01~0.3%, W: 10~12%, B: 1~3%, Zr: 0.1~0.3%, C: 0.1~0.5%, and Co is the balance.

[0075] Alternatively, in other embodiments, the chemical composition and mass percentage of the solder may be:

[0076] Ni: 9-11%, Cr: 10-20%, Ta: 0.01-3%, Ti: 0.01-0.3%, W: 8-14%, Zr: 0.1-0.3%, B: 2-3%, C: 0.3-0.5%, and Co is the balance.

[0077] Alternatively, in other embodiments, the chemical composition and mass percentage of the solder may be:

[0078] Ni: 9~11%, Cr: 14~18%, Ta: 0.01~3%, Ti: 0.01~0.3%, W: 10~12%, Zr: 0.1~0.3%, B: 2~3%, C: 0.3~0.5%, and Co is the balance.

[0079] In some possible implementations, the solder is provided in a spherical or nearly spherical powder form.

[0080] The present embodiment provides a method for preparing a cobalt-based high-temperature alloy brazing filler metal, which is applicable to any of the above-mentioned cobalt-based high-temperature alloy brazing filler metals. The preparation method comprises:

[0081] S1: melting and preparing the solder according to the composition of the solder, and melting it in a vacuum induction furnace to obtain a master alloy ingot.

[0082] Among them, raw materials with a purity greater than 99.99% need to be used to melt and mix the solder in proportion.

[0083] In some possible embodiments, the process parameters of the vacuum induction melting are: melting temperature of 1350-1450°C, vacuum degree of less than 5×10 -1 Pa, refining time 5 to 20 minutes.

[0084] S2: crushing and pulverizing the master alloy ingot by gas atomization under the protection of inert gas to obtain alloy powder.

[0085] In some possible implementations, the process parameters of the gas atomization method are: melting temperature 1450-1550° C., melting time 5-15 min, powder spraying gas is argon, and the mass flow rate is 2-5 kg / min.

[0086] S3: The alloy powder is sieved and powder with a particle size of -200 mesh is selected as the final cobalt-based high-temperature alloy brazing material.

[0087] In addition, an embodiment of the present application further provides a method for welding a cobalt-based high-temperature alloy brazing filler metal, which is applied to any of the above-mentioned cobalt-based high-temperature alloy brazing filler metals, and the welding method comprises:

[0088] S11: Grind the surface of the substrate to be welded to remove the surface oxide layer and impurities, exposing the surface to be welded with a metallic luster.

[0089] S12: uniformly mixing solder powder and oily binder in proportion to obtain solder paste, wherein the binder is added in an amount of 10% of the mass of the powder.

[0090] S13: evenly apply the solder paste to the surface to be soldered, and place the substrate coated with the solder paste in an oven, and dry it at 100-140° C. for 1 hour.

[0091] S14: placing the dried substrate coated with the paste solder into a vacuum brazing furnace for high-temperature brazing.

[0092] In some possible implementations, the welding parameters of the vacuum brazing furnace are as follows: the weld gap is 100 μm, the welding temperature is 1180-1240°C, the holding time is 0.5-4 hours, and the vacuum degree in the furnace is not higher than 1×10 -2 Pa.

[0093] Based on the above embodiments, this application provides a specific embodiment 1 and a comparative example 1 for comparison and explanation:

[0094] The brazing substrate used in Example 1 is a cobalt-based high-temperature alloy FSX414, the alloy composition of which is Cr: 29.5%, Ni: 10.5%, W: 7%, C: 0.25%, B: 0.01% by mass, and the rest is Co and unavoidable impurity elements.

[0095] The components of the cobalt-based high-temperature alloy solder used are Ni: 10.99%, Cr: 15.59%, Ta: 2%, Ti: 0.16%, W: 10.91%, B: 2.3%, Zr: 0.094%, C: 0.36%, and the balance is Co and unavoidable impurity elements.

[0096] The cobalt-based high-temperature alloy brazing filler metal in Example 1 was prepared according to the preparation method provided in the above example to obtain the final cobalt-based high-temperature alloy brazing filler metal. The prepared brazing filler metal powder was characterized by SEM. The results are as follows: Figure 1 Take a small amount of solder powder for DSC test, and the results are as follows Figure 2 shown.

[0097] In addition, the cobalt-based high-temperature alloy brazing material in Example 1 was welded according to the following welding process, and the weld microstructure of the brazed sample was observed. The results are as follows: Figure 3 shown.

[0098] The welding process of Example 1 includes the following:

[0099] 1) Grind the surface of the substrate to be welded to expose a fresh surface to be welded with metallic luster;

[0100] 2) Mix the solder powder with an oily binder to prepare a paste solder, with the binder added in an amount of 10% of the powder mass;

[0101] 3) Apply the solder paste to the surface to be soldered and dry it in an oven at 100-140℃ for 1 hour.

[0102] 4) The sample was placed in a vacuum brazing furnace for brazing. The weld gap was 100 μm, the welding temperature was 1220 °C, the holding time was 4 h, and the vacuum degree in the furnace was not higher than 1×10 -2 Pa.

[0103] The sample of Example 1 was subjected to a high temperature tensile test at 870°C. The sample of Example 1 broke at the substrate. The results are as follows: Figure 4 and Figure 5 shown.

[0104] Samples were taken from the weld after brazing for DSC testing, and the results were as follows: Figure 6 shown.

[0105] Among them, the brazing base material used in Comparative Example 1 is a cobalt-based high-temperature alloy FSX414: the alloy composition by mass percentage is Cr: 29.5%, Ni: 10.5%, W: 7%, C: 0.25%, B: 0.01%, and the rest is Co and unavoidable impurity elements.

[0106] Comparative Example 1 uses a cobalt-based high-temperature alloy solder MarM509B, the composition of the cobalt-based high-temperature alloy solder MarM509B is as follows by mass percentage: Ni: 10.91%, Cr: 23.53%, Ta: 3.45%, Ti: 0.31%, W: 7.09%, B: 2%, Zr: 0.18%, C: 0.6%, Si: 0.22%, and the balance is Co and unavoidable impurity elements.

[0107] Comparative Example 1 uses a cobalt-based high-temperature alloy solder MarM509B, and the composition of the cobalt-based high-temperature alloy solder MarM509B is as follows by mass percentage: Ni: 10.91%, Cr: 23.53%, Ta: 3.45%, Ti: 0.31%, W: 7.09%, B: 2%, Zr: 0.18%, C: 0.6%, Si: 0.22%, and the remainder is Co and unavoidable impurity elements. The morphology is spherical or nearly spherical powder particles with a particle size of -200 mesh.

[0108] The welding method adopted in Comparative Example 1 comprises the following steps:

[0109] S10: Grinding the surface of the substrate to be welded to expose a fresh surface to be welded with metallic luster;

[0110] S20: mixing the solder powder with an oily binder to prepare a paste solder, wherein the binder is added in an amount of 10% by weight of the powder;

[0111] S30: applying the solder paste to the surface to be soldered and drying it in an oven at 100°C to 140°C for 1 hour;

[0112] S40: The sample was placed in a vacuum brazing furnace for brazing. The weld gap was 100 μm, the welding temperature was 1200 °C, the holding time was 4 hours, and the vacuum degree in the furnace was not higher than 1×10 -2 Pa.

[0113] The weld structure of the sample of comparative example 1 was observed. Figure 7 shown.

[0114] The sample of comparative example 1 was subjected to a high temperature tensile test at 870°C. The sample of comparative example 1 was broken at the weld. The results are as follows: Figure 8 and Figure 9 shown.

[0115] By comparison, it can be seen that the cobalt-based high-temperature alloy brazing material prepared in this application uses B and C with small atomic radius as melting-reducing elements. After the brazing heat treatment, the melting-reducing elements C and B diffuse rapidly. The prepared brazed joint has the advantages of less precipitated phase, good joint strength and toughness, and high remelting temperature. It is suitable for high-reliability brazing connections of key hot-end components such as aircraft engine turbine blades.

[0116] Those skilled in the art will appreciate that all or part of the steps in the method of the above-described embodiment can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. The computer program is executed by at least one processor in the computer system to implement the steps in the method of the above-described embodiment.

[0117] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of each unit is merely a logical functional division, and other division methods may be used in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not implemented.

[0118] The steps in the method of the embodiment of the present application can be adjusted in order, combined, and deleted according to actual needs. The units in the device of the embodiment of the present application can be combined, divided, and deleted according to actual needs. In addition, the functional units in the various embodiments of the present application can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into a single unit.

[0119] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the existing technology, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling a computer device (which can be a personal computer, terminal, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application.

[0120] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0121] Obviously, those skilled in the art may make various modifications and variations to this application without departing from the spirit and scope of this application. Thus, as long as these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

[0122] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present application, and such modifications or substitutions should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A cobalt-based high-temperature alloy brazing filler metal, characterized in that: The chemical composition and mass percentage of the solder are: Ni: 7~13%, Cr: 10~20%, Ta: 0.01~3%, Ti: 0.01~0.3%, W: 8~14%, B: 1~3%, Zr: 0.01~0.4%, C: 0.1~0.5%, and Co is the balance.

2. The cobalt-based high-temperature alloy brazing filler metal according to claim 1, characterized in that: Ta: 1.5 to 2.5%, Ti: 0.1 to 0.2%.

3. The cobalt-based high-temperature alloy brazing filler metal according to claim 1, characterized in that: Cr: 14-18%, W: 10-12%.

4. The cobalt-based high-temperature alloy brazing filler metal according to claim 1, characterized in that: B: 2 to 3%, C: 0.3 to 0.5%.

5. The cobalt-based high-temperature alloy brazing filler metal according to claim 1, characterized in that: The solder is in the form of spherical or nearly spherical powder.

6. A method for preparing a cobalt-based high-temperature alloy brazing material, characterized in that: The cobalt-based high-temperature alloy brazing filler metal according to any one of claims 1 to 5, wherein the preparation method comprises: S1: melting and preparing the solder according to the composition of the solder, and melting it in a vacuum induction furnace to obtain a master alloy ingot; S2: crushing the master alloy ingot into powder by gas atomization under inert gas protection to obtain alloy powder; S3: The alloy powder is sieved and powder with a particle size of -200 mesh is selected as the final cobalt-based high-temperature alloy brazing material.

7. The preparation method according to claim 6, characterized in that The process parameters of the vacuum induction melting are as follows: melting temperature is 1350-1450°C, vacuum degree is less than 5×10 -1 Pa, refining time 5 to 20 minutes.

8. The preparation method according to claim 6, characterized in that The process parameters of the gas atomization method are: melting temperature 1450-1550° C., melting time 5-15 min, argon as powder spraying gas, and mass flow rate 2-5 kg / min.

9. A method for welding cobalt-based high-temperature alloy brazing material, characterized in that: The cobalt-based high-temperature alloy brazing filler metal according to any one of claims 1 to 5, wherein the welding method comprises: S11: Grind the surface of the substrate to be welded to remove the surface oxide layer and impurities, exposing the surface to be welded with a metallic luster. S12: uniformly mixing solder powder and oily binder in proportion to obtain solder paste, wherein the binder is added in an amount of 10% of the mass of the powder. S13: evenly apply the solder paste to the surface to be soldered, and place the substrate coated with the solder paste in an oven, and dry it at 100-140° C. for 1 hour. S14: placing the dried substrate coated with the paste solder into a vacuum brazing furnace for high-temperature brazing.

10. The welding method according to claim 9, characterized in that: The welding parameters of the vacuum brazing furnace are as follows: the weld gap is 100 μm, the welding temperature is 1180-1240 °C, the holding time is 0.5-4 hours, and the vacuum degree in the furnace is not higher than 1×10 -2 Pa.

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