Nickel-based flux-cored wire and preparation method thereof

Abstract

The invention relates to the technical field of flux-cored wires, and particularly discloses a nickel-based flux-cored wire and a preparation method thereof.Zirconia is generated on the surfaces of boron nitride whiskers in situ through a sol method, and the wear resistance and the mechanical property of the flux-cored wire are improved through the combined action of the high hardness of the boron nitride whiskers and the phase change toughening characteristic of the zirconia; 4-vinylphenylboronic acid is grafted to the surface of the boron nitride loaded zirconium oxide material through an addition reaction between double bonds, and boric acid groups in the 4-vinylphenylboronic acid can fully refine the raw materials and promote mutual uniform mixing, so that the mechanical property of the nickel-based flux-cored wire is enhanced; meanwhile, the 4-vinyl phenylboronic acid polymer is decomposed at high temperature to generate boron oxide, the boron oxide and other components (such as aluminum oxide) in the slag can form a low-melting-point eutectic compound, the slag is made to flow more easily, the fluidity and wettability of the welding slag are improved, and therefore the welding performance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of flux-cored wires, and particularly to a nickel-based flux-cored wire and a preparation method thereof. Background Art

[0002] In the field of welding materials technology, traditional welding processes mainly use electrodes and solid wires as filler materials, but they have significant limitations in terms of welding efficiency, metallurgical properties, and process adaptability. Electrodes achieve molten pool protection and alloy transition through an external coating, but their intermittent welding characteristics result in low production efficiency, poor operation flexibility, and the coating is prone to moisture absorption and insufficient composition stability, making it difficult to meet the requirements of automated production. Solid wires are suitable for continuous welding, but their alloying elements can only be provided by the wire base material, with limited composition design and unable to achieve complex metallurgical reaction control. Especially when dealing with high-strength steel, weathering steel, or special working conditions (such as low temperature, corrosive environment), the mechanical properties and crack resistance of the weld seam are difficult to meet the requirements.

[0003] Flux-cored wires (also known as metal-cored wires), as a new generation of welding materials, combine the metallurgical functions of electrode coatings and the continuous wire feeding advantages of solid wires through a composite structure of steel strips wrapped with powder. Their flux core composition can flexibly blend alloying elements (such as Mn, Si, Ni, Mo, etc.), deoxidizers (such as ferrosilicon, ferromanganese), slag formers (such as fluorite, titanium dioxide), and arc stabilizers (such as potassium and sodium compounds) to form a combined gas-slag protection during welding, effectively isolating the oxidation and nitridation of the molten pool by air. At the same time, desulfurization, dephosphorization, and purification of the weld seam are achieved through the floating of the slag. In addition, the continuous wire feeding characteristic of flux-cored wires supports fully automatic or semi-automatic welding processes, significantly improving the deposition efficiency (up to 85% - 90%), reducing the groove machining amount by increasing the weld cross-section, reducing the consumption of deposited metal, and showing significant economy in the welding of large structural parts.

[0004] Nickel-based wires, with their excellent corrosion resistance and characteristics of good plasticity, being deformable both hot and cold, and easy to process and form, have been widely used in fields such as petrochemical, metallurgy, atomic energy, and aviation. However, existing nickel-based wires are prone to fracture or failure when facing high-stress and heavy-load environments, restricting their process performance and application scope. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a nickel-based flux-cored wire and a preparation method thereof.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions: A nickel-based flux-cored wire, the nickel-based flux-cored wire comprising a welding skin and a flux core, and the flux core being composed of the following raw materials in parts by weight: 25-35 parts of nickel powder, 8-12 parts of chromium powder, 5-10 parts of boron nitride composite material, 2-5 parts of manganese powder, 4-6 parts of molybdenum powder, 3-5 parts of iron powder, 0.5-1 part of titanium powder, 1-2 parts of aluminum powder, and 2-3 parts of calcium fluoride.

[0007] In the technical solution disclosed in the present invention, the number of parts of nickel powder can be selected from 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0008] The nickel powder provided by the present invention can moderately increase the strength of the welded joint through the ferrite solution strengthening effect. Nickel is an element that forms and stabilizes austenite and can exist in the form of mutual solubility with iron in the weld in ferrite and austenite, thereby strengthening the weld metal.

[0009] In the technical solution disclosed in the present invention, the number of parts of chromium powder can be selected from 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0010] The addition of chromium powder can significantly improve the corrosion resistance of the deposited metal, especially the pitting corrosion resistance; chromium forms a stable passive film in the deposited metal, thereby improving the corrosion resistance of the weld.

[0011] In the technical solution disclosed in the present invention, the number of parts of the boron nitride composite material can be selected from 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0012] Specifically, the preparation method of the boron nitride composite material is as follows: S1. Dissolve soluble zirconium salt in deionized water, then add boron nitride whiskers thereto, disperse evenly, adjust the pH of the solution to 9-10, remove the solvent water by rotary evaporation, and then calcine in a nitrogen atmosphere, cool and grind to obtain a boron nitride-supported zirconia material; S2. Disperse the boron nitride-supported zirconia material in an ethanol aqueous solution, then add a vinyl silane coupling agent thereto, stir, and then filter, wash, and dry to obtain a vinyl-modified material; S3. Disperse the vinyl-modified material in an organic solvent, then add 4-vinylbenzeneboronic acid and benzoyl peroxide thereto, heat and react, and after the reaction is completed, filter, wash, and dry to obtain the boron nitride composite material.

[0013] In the technical solution disclosed by the present invention, in step S1, the mass ratio of the soluble zirconium salt to the boron nitride whisker is 1-2:1-2. In some embodiments of the present invention, for example, 1:1, 1:1.5, 1:2, 2:1, 2:1.5, 2:2 can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0014] In the technical solution disclosed by the present invention, the soluble zirconium salt is selected from zirconium oxychloride, zirconium sulfate or zirconium nitrate.

[0015] In the technical solution disclosed by the present invention, in step S1, the calcination temperature is 600-800 °C. In some embodiments of the present invention, for example, 600 °C, 650 °C, 700 °C, 750 °C, 800 °C can be selected; the calcination time is 1-2 h, for example, 1 h, 1.5 h, 2 h can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0016] In the technical solution disclosed by the present invention, in step S2, the mass ratio of the boron nitride-supported zirconia material to the vinyl silane coupling agent is 8-12:1-3. In some embodiments of the present invention, for example, 8:1, 8:2, 8:3, 10:1, 10:2, 10:3, 12:1, 12:2, 12:3 can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0017] In the technical solution disclosed by the present invention, the vinyl silane coupling agent is selected from vinyltrimethylsilane or vinyltriethylsilane.

[0018] In the technical solution disclosed by the present invention, in step S3, the mass ratio of the vinyl-modified material, 4-vinylbenzeneboronic acid and benzoyl peroxide is 8-12:4-6:0.5-1.

[0019] In the technical solution disclosed by the present invention, in step S3, the temperature of the heating reaction is 60-80 °C, for example, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C can be selected; the heating reaction time is 2-4 h, for example, 2 h, 2.5 h, 3 h, 3.5 h, 4 h can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0020] In the present invention, zirconia is in-situ generated on the surface of boron nitride whiskers by the sol method. The loaded zirconia particles can serve as heterogeneous nucleation cores, promoting the refinement of the grains of the deposited metal and forming a composite wear-resistant structure of "high-hardness boron nitride + fine-grained matrix". The combined action of the high hardness of the boron nitride whiskers themselves and the transformation toughening characteristics of zirconia enhances the wear resistance and mechanical properties of the flux-cored wire. Subsequently, through the addition reaction between double bonds, 4-vinylbenzeneboronic acid is grafted onto the surface of the boron nitride-supported zirconia material. The boronic acid group in 4-vinylbenzeneboronic acid can adsorb with the molecules on the surface of other raw materials, which can fully refine the raw materials and promote their uniform mixing, thereby enhancing the mechanical properties of the nickel-based flux-cored wire. At the same time, the 4-vinylbenzeneboronic acid polymer decomposes at high temperatures to generate boron oxide, which can form eutectic compounds with low melting points with other components in the slag (such as alumina, etc.), making the slag flow more easily, improving the fluidity and wettability of the welding slag, and thus enhancing the welding performance. In addition, some boron elements may dissolve into the weld metal, playing a certain alloying role and further improving the mechanical properties of the flux-cored wire.

[0021] In the technical solution disclosed in the present invention, the number of parts of manganese powder can be selected as 2 parts, 3 parts, 4 parts, 5 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0022] The addition of manganese powder can improve the welding process performance, such as stabilizing the arc, reducing spatter, making the welding process more stable, being able to increase the strength and toughness of the weld metal. At the same time, manganese powder can effectively remove oxygen and sulfur in the weld during the welding process, reduce the oxide inclusions in the weld and the content of sulfur in the weld, and reduce the risk of hot cracks.

[0023] In the technical solution disclosed in the present invention, the number of parts of molybdenum powder can be selected as 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0024] The addition of molybdenum powder can not only increase the strength of the welded joint through solid solution strengthening, but also improve the toughness; molybdenum elements have the effect of delaying the precipitation and growth of proeutectoid ferrite, which is beneficial to the formation of acicular ferrite tissue with a high density of dislocations in the weld.

[0025] In the technical solution disclosed in the present invention, the number of parts of iron powder can be selected as 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0026] The iron powder provided by the present invention will melt and fill into the weld during the welding process, so it can increase the metal filling amount of the weld, thereby improving the welding speed and deposition rate.

[0027] In the technical solution disclosed by the present invention, the amount of titanium powder can be selected as 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0028] The addition of titanium powder can form more inclusions within the crystal grains, thus becoming nucleation cores, promoting the formation of acicular ferrite structure in the weld, refining the grains. In addition, during the formation of the deposited metal, it also has the function of capturing hydrogen, effectively reducing the content of diffusible hydrogen in the deposited metal, and improving the mechanical properties of the welded joint.

[0029] In the technical solution disclosed by the present invention, the amount of aluminum powder can be selected as 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0030] During the welding process, aluminum powder can react with oxygen in the weld to form aluminum oxide, thereby reducing the oxygen content in the weld and improving the purity of the weld. This deoxidation effect helps to improve the welding quality; at the same time, aluminum powder can reduce the melting point during the welding process, improve the fluidity of the slag, make the weld smoother, and reduce defects such as pores and cracks.

[0031] In the technical solution disclosed by the present invention, the amount of calcium fluoride can be selected as 2 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts, 2.9 parts, 3 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0032] Calcium fluoride is a commonly used slag-forming agent, which can form slag during the welding process, cover the surface of the molten pool, and play a role in isolating air and protecting the molten pool from oxidation and pollution.

[0033] In the technical solution disclosed by the present invention, the flux core accounts for 15 - 25% of the mass of the flux-cored wire. In the technical solution disclosed by the present invention, for example, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25% can be selected, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0034] The present invention also provides a preparation method of the above nickel-based flux-cored wire, including the following steps: (1) Mix nickel powder, chromium powder, boron nitride composite material, manganese powder, molybdenum powder, iron powder, titanium powder, aluminum powder and calcium fluoride evenly by weight and then dry to obtain the flux core; (2) Roll the welding skin into a U shape, add the flux core, then seal and roll it into an O shape, and obtain the nickel-based flux-cored wire through drawing and reducing the diameter.

[0035] In the technical solution disclosed by the present invention, in step S1, the drying temperature is 100 - 120 °C, for example, 100 °C, 105 °C, 110 °C, 115 °C, 120 °C can be selected; the drying time is 1 - 3 h, for example, 1 h, 1.5 h, 2 h, 2.5 h, 3 h can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0036] In the technical solution disclosed by the present invention, in step S2, the diameter of the flux-cored wire is 1.2 - 1.8 mm, for example, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0037] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, zirconia is in-situ generated on the surface of boron nitride whiskers by the sol-gel method. The loaded zirconia particles can serve as heterogeneous nucleation cores to promote the refinement of the deposited metal grains, forming a composite wear-resistant structure of "high-hardness boron nitride + fine-grained matrix". The combined action of the high hardness of the boron nitride whiskers themselves and the transformation toughening characteristics of zirconia improves the wear resistance and mechanical properties of the flux-cored wire; subsequently, through the addition reaction between double bonds, 4-vinylbenzeneboronic acid is grafted onto the surface of the boron nitride-supported zirconia material. The boronic acid group in 4-vinylbenzeneboronic acid can adsorb with the molecules on the surface of other raw materials, which can fully refine the raw materials and promote their uniform mixing, thereby enhancing the mechanical properties of the nickel-based flux-cored wire; at the same time, the 4-vinylbenzeneboronic acid polymer decomposes at high temperature to generate boron oxide, and boron oxide can form eutectic compounds with low melting points with other components in the slag (such as alumina, etc.), making the slag easier to flow, improving the fluidity and wettability of the welding slag, and thus improving the welding performance; in addition, some boron elements may dissolve into the weld metal, playing a certain alloying role and further improving the mechanical properties of the flux-cored wire. Specific embodiments

[0038] The following further elaborates on the present invention through specific preferred embodiments, but the present invention is not limited to the following embodiments.

[0039] It should be noted that unless otherwise specified, the chemical reagents involved in the present invention are purchased through commercial channels.

[0040] The purity of the nickel powder used in the embodiments of the present invention is ≥99.8%, and the particle size is 150 mesh; The purity of chromium powder, manganese powder, molybdenum powder, iron powder, titanium powder, aluminum powder, and calcium fluoride is ≥99.9%, and the particle size is 200 - 300 mesh; The diameter of the boron nitride whiskers is 1 μm, and the length is 10 - 20 μm; The welding skin is a nickel-based alloy Ni-625, with a width of 10 mm and a thickness of 0.3 mm.

[0041] Example 1 A preparation method of a nickel-based flux-cored wire includes the following steps: (1) Mix 30 parts of nickel powder, 10 parts of chromium powder, 8 parts of boron nitride composite material, 4 parts of manganese powder, 5 parts of molybdenum powder, 4 parts of iron powder, 0.8 part of titanium powder, 1 part of aluminum powder and 2 parts of calcium fluoride evenly, and then dry at 120 °C for 1 h to obtain the flux core; Among them, the preparation method of the boron nitride composite material is as follows: S1. Dissolve 5 g of zirconium oxychloride in 100 mL of deionized water, then add 5 g of boron nitride whiskers thereto, disperse evenly, adjust the pH of the solution to 10, remove the solvent water by rotary evaporation, and then calcine in a nitrogen atmosphere. The calcination temperature is 600 °C, the calcination time is 2 h, and after cooling, grind to obtain boron nitride supported zirconia material; S2. Disperse 10 g of boron nitride supported zirconia material in 100 mL of 80 wt% ethanol aqueous solution, then add 2 g of vinyltriethylsilane thereto, stir at room temperature for 2 h, and then filter, wash and dry to obtain a vinyl modified material; S3. Disperse 8 g of vinyl modified material in 100 mL of organic solvent DMF, then add 4 g of 4-vinylbenzeneboronic acid and 0.5 g of benzoyl peroxide thereto, heat and react in a nitrogen atmosphere. The heating reaction temperature is 60 °C, the heating reaction time is 4 h. After the reaction is completed, filter, wash and dry to obtain the boron nitride composite material.

[0042] (2) Roll the welding skin into a U shape, add the flux core, then seal and roll it into an O shape, and then draw and reduce the diameter to obtain the nickel-based flux-cored wire. The flux core accounts for 20% of the mass of the flux-cored wire, and the diameter of the nickel-based flux-cored wire is 1.5 mm.

[0043] Example 2 A preparation method of a nickel-based flux-cored wire includes the following steps: (1) Mix 25 parts of nickel powder, 12 parts of chromium powder, 10 parts of boron nitride composite material, 2 parts of manganese powder, 6 parts of molybdenum powder, 3 parts of iron powder, 0.5 part of titanium powder, 1 part of aluminum powder and 2 parts of calcium fluoride evenly, and then dry at 120 °C for 1 h to obtain the flux core; Among them, the preparation method of the boron nitride composite material is as follows: S1. Dissolve 5 g of zirconium oxychloride in 100 mL of deionized water, then add 8 g of boron nitride whiskers thereto, disperse evenly, adjust the pH of the solution to 10, remove the solvent water by rotary evaporation, and then calcine under a nitrogen atmosphere at a calcination temperature of 800 °C for 1 h. After cooling, grind to obtain a boron nitride-supported zirconia material; S2. Disperse 8 g of the boron nitride-supported zirconia material in 100 mL of an 80 wt% ethanol aqueous solution, then add 1 g of vinyltriethylsilane thereto, stir at room temperature for 2 h, and then filter, wash, and dry to obtain a vinyl-modified material; S3. Disperse 12 g of the vinyl-modified material in 100 mL of an organic solvent DMF, then add 6 g of 4-vinylbenzeneboronic acid and 1 g of benzoyl peroxide thereto, heat and react under a nitrogen atmosphere at a heating reaction temperature of 80 °C for 2 h. After the reaction is completed, filter, wash, and dry to obtain the boron nitride composite material.

[0044] (2) Roll the welding skin into a U shape, add the flux-cored wire, then seal it and roll it into an O shape, and then draw and reduce the diameter to obtain a nickel-based flux-cored wire. The flux-cored wire accounts for 20% of the mass of the nickel-based flux-cored wire, and the diameter of the nickel-based flux-cored wire is 1.5 mm.

[0045] Example 3 A method for preparing a nickel-based flux-cored wire, comprising the following steps: (1) Mix 35 parts of nickel powder, 8 parts of chromium powder, 5 parts of the boron nitride composite material, 2 parts of manganese powder, 4 parts of molybdenum powder, 5 parts of iron powder, 0.5 part of titanium powder, 1.5 parts of aluminum powder, and 2.5 parts of calcium fluoride evenly and dry at 120 °C for 1 h to obtain the flux-cored wire; Among them, the preparation method of the boron nitride composite material is as follows: S1. Dissolve 5 g of zirconium oxychloride in 100 mL of deionized water, then add 10 g of boron nitride whiskers thereto, disperse evenly, adjust the pH of the solution to 10, remove the solvent water by rotary evaporation, and then calcine under a nitrogen atmosphere at a calcination temperature of 800 °C for 1 h. After cooling, grind to obtain a boron nitride-supported zirconia material; S2. Disperse 12 g of the boron nitride-supported zirconia material in 100 mL of an 80 wt% ethanol aqueous solution, then add 3 g of vinyltriethylsilane thereto, stir at room temperature for 2 h, and then filter, wash, and dry to obtain a vinyl-modified material; S3. Disperse 10 g of vinyl-modified material in 100 mL of organic solvent DMF, then add 5 g of 4-vinylbenzeneboronic acid and 0.8 g of benzoyl peroxide thereto, and heat and react under a nitrogen atmosphere. The temperature of the heat reaction is 80 °C, and the time of the heat reaction is 2 h. After the reaction is completed, filter, wash, and dry to obtain the boron nitride composite material.

[0046] (2) Roll the welding skin into a U shape, add the flux-cored wire, then seal and roll it into an O shape, and perform drawing and reducing in diameter to obtain the nickel-based flux-cored wire. The flux-cored wire accounts for 15% of the mass of the nickel-based flux-cored wire, and the diameter of the nickel-based flux-cored wire is 1.5 mm.

[0047] Example 4 A preparation method of a nickel-based flux-cored wire includes the following steps: (1) Mix 25 parts of nickel powder, 12 parts of chromium powder, 6 parts of boron nitride composite material, 4 parts of manganese powder, 4 parts of molybdenum powder, 4 parts of iron powder, 1 part of titanium powder, 1 part of aluminum powder, and 2.5 parts of calcium fluoride evenly, and dry at 120 °C for 1 h to obtain the flux-cored wire. Among them, the preparation method of the boron nitride composite material is as follows: S1. Dissolve 10 g of zirconium oxychloride in 100 mL of deionized water, then add 8 g of boron nitride whiskers thereto, disperse evenly, adjust the pH of the solution to 10, remove the solvent water by rotary evaporation, then calcine under a nitrogen atmosphere. The calcination temperature is 800 °C, and the calcination time is 1 h. After cooling, grind to obtain the boron nitride-supported zirconia material. S2. Disperse 8 g of boron nitride-supported zirconia material in 100 mL of 80 wt% ethanol aqueous solution, then add 1 g of vinyltriethylsilane thereto, stir at room temperature for 2 h, and then filter, wash, and dry to obtain the vinyl-modified material. S3. Disperse 10 g of vinyl-modified material in 100 mL of organic solvent DMF, then add 5 g of 4-vinylbenzeneboronic acid and 0.8 g of benzoyl peroxide thereto, and heat and react under a nitrogen atmosphere. The temperature of the heat reaction is 60 °C, and the time of the heat reaction is 4 h. After the reaction is completed, filter, wash, and dry to obtain the boron nitride composite material.

[0048] (2) Roll the welding skin into a U shape, add the flux-cored wire, then seal and roll it into an O shape, and perform drawing and reducing in diameter to obtain the nickel-based flux-cored wire. The flux-cored wire accounts for 25% of the mass of the nickel-based flux-cored wire, and the diameter of the nickel-based flux-cored wire is 1.5 mm.

[0049] Example 5 A preparation method of a nickel-based flux-cored wire includes the following steps: (1) Mix 35 parts of nickel powder, 12 parts of chromium powder, 10 parts of boron nitride composite material, 5 parts of manganese powder, 6 parts of molybdenum powder, 5 parts of iron powder, 1 part of titanium powder, 2 parts of aluminum powder and 3 parts of calcium fluoride evenly, and then dry at 120 °C for 1 h to obtain the flux-cored wire; Among them, the preparation method of the boron nitride composite material is as follows: S1. Dissolve 8 g of zirconium oxychloride in 100 mL of deionized water, then add 8 g of boron nitride whiskers thereto, disperse evenly, adjust the pH of the solution to 10, remove the solvent water by rotary evaporation, and then calcine in a nitrogen atmosphere. The calcination temperature is 600 °C, the calcination time is 2 h, and after cooling, grind to obtain the boron nitride-supported zirconium oxide material; S2. Disperse 10 g of the boron nitride-supported zirconium oxide material in 100 mL of an 80 wt% ethanol aqueous solution, then add 2 g of vinyltriethylsilane thereto, stir at room temperature for 2 h, and then filter, wash, and dry to obtain the vinyl-modified material; S3. Disperse 8 g of the vinyl-modified material in 100 mL of the organic solvent DMF, then add 4 g of 4-vinylphenylboronic acid and 0.5 g of benzoyl peroxide thereto, heat and react in a nitrogen atmosphere. The heating reaction temperature is 60 °C, and the heating reaction time is 4 h. After the reaction is completed, filter, wash, and dry to obtain the boron nitride composite material.

[0050] (2) Roll the welding skin into a U shape, add the flux-cored wire, then seal it and roll it into an O shape, and then perform drawing and reducing to obtain the nickel-based flux-cored wire. The flux-cored wire accounts for 18% of the mass of the flux-cored wire, and the diameter of the nickel-based flux-cored wire is 1.5 mm.

[0051] Comparative Example 1 A preparation method of a nickel-based flux-cored wire includes the following steps: (1) Mix 30 parts of nickel powder, 10 parts of chromium powder, 8 parts of boron nitride whiskers, 4 parts of manganese powder, 5 parts of molybdenum powder, 4 parts of iron powder, 0.8 part of titanium powder, 1 part of aluminum powder and 2 parts of calcium fluoride evenly, and then dry at 120 °C for 1 h to obtain the flux-cored wire; (2) Roll the welding skin into a U shape, add the flux-cored wire, then seal it and roll it into an O shape, and then perform drawing and reducing to obtain the nickel-based flux-cored wire. The flux-cored wire accounts for 20% of the mass of the flux-cored wire, and the diameter of the nickel-based flux-cored wire is 1.5 mm.

[0052] Compared with Example 1, in Comparative Example 1, the boron nitride whiskers were not modified.

[0053] Comparative Example 2 A preparation method of a nickel-based flux-cored wire includes the following steps: (1) Mix 30 parts of nickel powder, 10 parts of chromium powder, 8 parts of boron nitride composite material, 4 parts of manganese powder, 5 parts of molybdenum powder, 4 parts of iron powder, 0.8 parts of titanium powder, 1 part of aluminum powder and 2 parts of calcium fluoride evenly, and then dry at 120 °C for 1 h to obtain the flux cored wire; Among them, the preparation method of the boron nitride composite material is as follows: Dissolve 5 g of zirconium oxychloride in 100 mL of deionized water, then add 5 g of boron nitride whiskers thereto, disperse evenly, adjust the pH of the solution to 10, remove the solvent water by rotary evaporation, and then calcine in a nitrogen atmosphere. The calcination temperature is 600 °C, the calcination time is 2 h, and after cooling, grind to obtain the boron nitride composite material; (2) Roll the welding skin into a U shape, add the flux cored wire, then seal it and roll it into an O shape, and through drawing and reducing the diameter, the nickel-based flux cored wire is obtained. The flux cored wire accounts for 20% of the mass of the flux cored wire, and the diameter of the nickel-based flux cored wire is 1.5 mm.

[0054] Compared with Example 1, in Comparative Example 2, grafting of 4-vinylbenzeneboronic acid was not carried out.

[0055] Comparative Example 3 A preparation method of a nickel-based flux cored wire includes the following steps: (1) Mix 30 parts of nickel powder, 10 parts of chromium powder, 8 parts of boron nitride composite material, 4 parts of manganese powder, 5 parts of molybdenum powder, 4 parts of iron powder, 0.8 parts of titanium powder, 1 part of aluminum powder and 2 parts of calcium fluoride evenly, and then dry at 120 °C for 1 h to obtain the flux cored wire; Among them, the preparation method of the boron nitride composite material is as follows: S1. Disperse 10 g of boron nitride whiskers in 100 mL of 80 wt% ethanol aqueous solution, then add 2 g of vinyltriethylsilane thereto, stir at room temperature for 2 h, and then filter, wash and dry to obtain vinyl-modified boron nitride whiskers; S2. Disperse 8 g of vinyl-modified boron nitride whiskers in 100 mL of organic solvent DMF, then add 4 g of 4-vinylbenzeneboronic acid and 0.5 g of benzoyl peroxide thereto, heat and react in a nitrogen atmosphere. The heating reaction temperature is 60 °C, and the heating reaction time is 4 h. After the reaction is completed, filter, wash and dry to obtain the boron nitride composite material.

[0056] (2) Roll the welding skin into a U shape, add the flux cored wire, then seal it and roll it into an O shape, and through drawing and reducing the diameter, the nickel-based flux cored wire is obtained. The flux cored wire accounts for 20% of the mass of the flux cored wire, and the diameter of the nickel-based flux cored wire is 1.5 mm.

[0057] Compared with Example 1, in Comparative Example 3, the boron nitride whiskers were not subjected to zirconia loading treatment.

[0058] The nickel-based flux-cored wires prepared in Examples 1-2 and Comparative Examples 1-3 were used to weld two Ni625 nickel-based alloy plates by a welding machine. The shielding gas was argon, the welding voltage was 18-20 V, the welding current was 130-150 A, the welding speed was 25 cm / min, and the wire feeding speed was 150 cm / min. The properties of the deposited metal of the welded parts were measured. The wear resistance was measured according to the national standard GB / T 12444-2006, the mechanical properties were tested according to the national standard GB / T 2652-2022, and the impact toughness was measured according to the national standard GB / T 2650-2022. The test results are shown in Table 1.

[0059] Table 1 Performance test results of different groups As can be seen from the table, compared with Comparative Examples 1-3, the nickel-based flux-cored wires prepared in the examples of the present invention have excellent wear resistance and mechanical properties.

[0060] Finally, it should be noted that the above embodiments do not limit the present invention in any form. For those skilled in the art, based on the present invention, some modifications and improvements can be made. Therefore, any modification or improvement made without departing from the spirit of the present invention falls within the scope of protection of the present invention.

Claims

1. A nickel-based flux-cored welding wire, characterized in that: The nickel-based flux-cored welding wire comprises a welding skin and a flux core, and the flux core is composed of the following raw materials in parts by weight: 25-35 parts of nickel powder, 8-12 parts of chromium powder, 5-10 parts of boron nitride composite material, 2-5 parts of manganese powder, 4-6 parts of molybdenum powder, 3-5 parts of iron powder, 0.5-1 parts of titanium powder, 1-2 parts of aluminum powder, and 2-3 parts of calcium fluoride.

2. The nickel-based flux-cored welding wire according to claim 1, characterized in that: The preparation method of the boron nitride composite material is as follows: S1. Dissolve a soluble zirconium salt in deionized water, then add boron nitride whiskers thereto and disperse them evenly, adjust the pH of the solution to 9-10, remove the solvent water by rotary evaporation, then calcine under a nitrogen atmosphere, and grind after cooling to obtain a boron nitride-loaded zirconium oxide material; S2, dispersing the boron nitride-loaded zirconium oxide material in an ethanol aqueous solution, then adding a vinyl silane coupling agent thereto, stirring, and then filtering, washing, and drying to obtain a vinyl-modified material; S3, dispersing the vinyl modified material in an organic solvent, then adding 4-vinylbenzeneboric acid and benzoyl peroxide thereto, heating for reaction, and after the reaction is completed, filtering, washing and drying to obtain a boron nitride composite material.

3. The nickel-based flux-cored welding wire according to claim 2, characterized in that: In step S1, the mass ratio of the soluble zirconium salt to the boron nitride whiskers is 1-2:1-2, wherein the soluble zirconium salt is selected from zirconium oxychloride, zirconium sulfate or zirconium nitrate.

4. The nickel-based flux-cored welding wire according to claim 2, characterized in that: In step S1, the calcination temperature is 600-800°C, and the calcination time is 1-2h.

5. The nickel-based flux-cored welding wire according to claim 2, characterized in that: In step S2, the mass ratio of the boron nitride-loaded zirconium oxide material to the vinyl silane coupling agent is 8-12:1-3.

6. The nickel-based flux-cored welding wire according to claim 2, characterized in that: In step S3, the mass ratio of the vinyl modified material, 4-vinylbenzeneboric acid and benzoyl peroxide is 8-12:4-6:0.5-1.

7. The nickel-based flux-cored welding wire according to claim 2, characterized in that: In step S3, the heating reaction temperature is 60-80° C., and the heating reaction time is 2-4 hours.

8. The flux-cored welding wire according to claim 1, characterized in that: The flux core accounts for 15-25% of the mass of the flux cored welding wire.

9. The method for preparing the nickel-based flux-cored welding wire according to any one of claims 1 to 8, characterized in that: The steps include: (1) uniformly mixing nickel powder, chromium powder, boron nitride composite material, manganese powder, molybdenum powder, iron powder, titanium powder, aluminum powder and calcium fluoride according to weight proportions and drying the mixture to obtain a core; (2) The weld skin is rolled into a U-shape, a flux core is added, and then the weld is sealed and rolled into an O-shape. After drawing and reducing the diameter, a nickel-based flux-cored welding wire is obtained.

10. The preparation method according to claim 9, characterized in that: In step (2), the diameter of the nickel-based flux-cored welding wire is 1.2-1.8 mm.

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