A fan blade surfacing flux-cored wire and a method of manufacturing the same

Abstract

The application provides a fan blade surfacing flux-cored wire and a preparation method thereof, and relates to the field of welding materials.The fan blade surfacing flux-cored wire comprises a steel belt sheath and a flux core material, and the flux core material is filled in the steel belt sheath.The flux core material is composed of raw materials in the following mass percentages: high-carbon chromium iron: 70-78%, manganese-silicon alloy: 4-8%, silicon carbide: 3-6%, chromium iron carbide: 2-7%, titanium iron: 0.8-1.3%, graphite: 5.2-6.0%, silicon iron: 1.3-1.7%, quartz: 0.6-0.9%, and cobalt powder: 3-5%.The wear-resistant flux-cored wire and the preparation method thereof select high-chromium alloy cast iron as the welding material, so that the deposited metal after welding is mainly composed of the metallographic structure of martensite and alloy carbide, the high-hardness characteristics of the carbide are fully utilized, the wear resistance of the fan blade is improved, the service life of the fan blade is effectively prolonged, and the fan blade surfacing flux-cored wire is suitable for all types of flat welding and horizontal welding and has good compatibility with the welding position of the fan blade.

Description

Technical Field

[0001] This invention relates to the field of welding materials, specifically to a flux-cored welding wire for wind turbine blade overlay and its preparation method. Background Technology

[0002] Wind energy, as a clean and renewable energy source, has become one of the main energy sources for countries worldwide. Wind power generation boasts advantages such as environmental friendliness, wide distribution, and abundant resources. Wind turbines are mostly located in remote deserts or near-shore areas. The turbine blades are a crucial component of wind turbines, operating in a complex and harsh high-altitude environment that easily damages them, leading to corrosion, wear, pinholes, and edge cracks. If not repaired promptly, these issues can cause the generator set to stop operating or become unusable. Repairing wind turbine blades typically involves welding. However, the weld metal formed by existing welding wires is not suitable for the long-term operating environment of the wind turbine blades, making the weld joints prone to re-damage. Repeated welding further shortens the lifespan of the wind turbine blades. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the present invention provides a flux-cored welding wire for wind turbine blade welding and its preparation method, so as to improve the technical problem of not having a suitable welding wire for wind turbine blade welding.

[0004] To achieve the above and other related objectives, the present invention provides a flux-cored welding wire for wind turbine blade surfacing. The flux-cored welding wire comprises a steel strip sheath and a flux-cored material, wherein the flux-cored material is filled within the steel strip sheath. The flux-cored material is composed of the following raw materials by mass percentage:

[0005] High carbon ferrochrome: 70~82%, manganese silicon alloy: 4~8%, silicon carbide: 3~6%, ferrochrome carbide: 2~7%, ferrotitanium: 0.8~1.3%, graphite: 5.2~6.0%, ferrosilicon: 1.3~1.7%, quartz: 0.6~0.9%, cobalt powder: 3~5%.

[0006] In one example of the flux-cored welding wire for wind turbine blade overlay of the present invention, the mass of the flux-cored material is 14-17% of the sum of the mass of the flux-cored material and the mass of the steel strip sheath.

[0007] In one example of the flux-cored welding wire for wind turbine blade overlay of the present invention, the particle size of each raw material in the flux-cored material is 60~100 mesh.

[0008] In one example of the flux-cored welding wire for wind turbine blade overlay welding of the present invention, the diameter of the flux-cored welding wire is 1.2~1.6mm.

[0009] In one example of the flux-cored welding wire for wind turbine blade overlay of the present invention, the outer sheath of the steel strip is a carbon steel strip.

[0010] In one example of the flux-cored welding wire for wind turbine blade overlay of the present invention, the carbon steel strip has a carbon content of less than or equal to 0.04%, a silicon content of less than or equal to 0.03%, a phosphorus content of less than or equal to 0.02%, a sulfur content of less than or equal to 0.02%, and a manganese content of 0.15~0.35%.

[0011] This invention also provides a method for preparing flux-cored welding wire for wind turbine blade overlay welding, comprising the following steps:

[0012] Weigh each raw material and then dry it.

[0013] The dried raw materials are mixed evenly to obtain a core material mixture;

[0014] Carbon steel strip is rolled into a U-shaped groove;

[0015] The flux-cored material mixture is filled into a U-shaped groove, and then the openings of the U-shaped groove are butt-welded together to obtain the first welding wire;

[0016] The first welding wire is further rolled to reduce its diameter and then drawn into a wire drawing machine to a preset diameter to obtain the flux-cored welding wire for the wind turbine blade.

[0017] In one example of the preparation method of the wear-resistant flux-cored welding wire of the present invention, each raw material is dried at 190±5℃ and kept at that temperature for 60~100 minutes, and then cooled to room temperature before being removed from the furnace to obtain the dried raw materials.

[0018] In one example of the preparation method of the wear-resistant flux-cored welding wire of the present invention, high-frequency welding technology is used to weld the opening of the U-shaped groove together.

[0019] The present invention relates to a wear-resistant flux-cored welding wire and its preparation method, which results in a weld metal with a predominantly martensitic and alloy carbide microstructure, exhibiting excellent resistance to particle wear, high temperature resistance, and high hardness, effectively extending the service life of wind turbine blades; at the same time, reducing maintenance costs and the number of times wind turbine blades need repair; and is suitable for various flat and horizontal welding methods, with good compatibility with the welding positions on wind turbine blades. Detailed Implementation

[0020] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. It should also be understood that the terminology used in the embodiments of the present invention is for describing specific implementation schemes and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0021] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to those described, used, or made of materials in the embodiments of this invention.

[0022] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as part of the scope of the invention.

[0023] This invention provides a flux-cored welding wire for wind turbine blade surfacing. The flux-cored material is filled inside the outer sheath of the steel strip. The flux-cored material is composed of the following raw materials by mass percentage:

[0024] High-carbon ferrochrome: 70~82%. High-carbon ferrochrome is the main slag-forming agent and arc stabilizer in flux-cored welding wire formulations, accounting for the largest proportion in the flux-cored wire formulation. It can fully exert its effects of stabilizing the electric arc, covering welding slag, and improving the surface quality of the weld. The mass percentage of high-carbon ferrochrome can be any value within the range of 70~82%, such as 70%, 74%, 78%, 82%, etc.

[0025] Silicon manganese alloy: 4-8%. Silicon-manganese alloy acts as the main deoxidizer and also has an alloying effect, improving the elongation of the weld metal. Appropriate amounts of silicon and manganese ensure the strength and low-temperature toughness of the weld metal, while also guaranteeing good weld formation. The exothermic reaction accelerates the melting of the welding wire, increasing melting efficiency, and reduces the surface tension of the molten droplets, minimizing spatter. The mass percentage of silicon manganese alloy can be any value within the range of 4-8%, such as 4%, 5%, 7%, or 8%.

[0026] Silicon carbide: 3~6%. Silicon carbide imparts corrosion resistance, high temperature resistance, high strength, good thermal conductivity, and impact resistance to the welded metal. The mass percentage of silicon carbide can be any value within the range of 3~6%, such as 3%, 4%, 5%, 6%, etc.

[0027] Ferrochromium carbide: 2~7%. Ferrochromium carbide has high chemical stability, is not easily oxidized and corroded in the atmosphere, and has high hardness and wear resistance, thereby improving the wear resistance and corrosion resistance of the deposited metal. The mass percentage of ferrochromium carbide can be any value in the range of 2~7%, such as 2%, 3%, 5%, 7%.

[0028] Titanium ferrophosphate: 0.8~1.3%. As a deoxidizer, an appropriate amount of titanium can significantly improve the impact toughness of the deposited metal. Furthermore, titanium combines with carbon to form a stable compound, preventing the formation of chromium carbide, thereby reducing intergranular corrosion and improving the performance of the deposited metal. The mass percentage of titanium ferrophosphate can be any value within the range of 0.8~1.3%, such as 0.8%, 0.9%, 1.15%, or 1.3%.

[0029] Graphite: 5.2~6.0%. Graphite helps increase the conductivity of the welding wire and the fluidity of the powder; graphite also acts as a deoxidizer and ensures the strength of the deposited metal in the flux-cored welding wire. The mass percentage of graphite can be any value within the range of 5.2% to 6%, such as 5.2%, 5.4%, 5.6%, 6%.

[0030] Ferrosilicon: 1.3~1.7%, used as an arc stabilizer to ensure good slag removal, less spatter, and aesthetically pleasing weld formation. The mass percentage of ferrosilicon can be any value within the range of 1.3~1.7%, such as 1.3%, 1.5%, or 1.7%.

[0031] Quartz: 0.6~0.9%, used as an arc stabilizer to ensure good slag removal, less spatter, and aesthetically pleasing weld formation. The mass percentage of quartz can be any value within the range of 0.6~0.9%, such as 0.6%, 0.7%, 0.8%, 0.9%.

[0032] Cobalt powder: 3~5%, used as a binder to ensure that the deposited metal has a certain degree of toughness. The mass percentage of cobalt powder can be any value within the range of 3~5%, such as 3%, 4%, 5%.

[0033] In one example of the flux-cored welding wire for wind turbine blade overlay of the present invention, the mass of the flux-cored material is 14 to 17% of the sum of the mass of the flux-cored material and the mass of the steel strip sheath, for example, any value within the range of 14 to 17%, such as 14%, 15%, 16%, 17%, etc.

[0034] In one example of the flux-cored welding wire for wind turbine blade surfacing according to the present invention, the particle size of each raw material in the flux-cored material is 60-100 mesh. Among them, the high-carbon ferrochrome has a mesh size of 80 mesh, and the particle size satisfies that the powder particles passing through 80 mesh are greater than or equal to 95%; the mesh size of the remaining components is 60 mesh, and the particle size satisfies that the powder particles passing through 60 mesh are greater than or equal to 95%.

[0035] In one example of the flux-cored welding wire for wind turbine blade overlay welding of the present invention, the diameter of the flux-cored welding wire is 1.2~1.6mm, for example, any value within the range of 1.2~1.6mm such as 1.2mm, 1.5mm, 1.6mm, etc.

[0036] In one example of the wear-resistant flux-cored welding wire of the present invention, the outer sheath of the steel strip is a carbon steel strip.

[0037] In one example of the flux-cored welding wire for wind turbine blade overlay of the present invention, the carbon steel strip has a carbon content of less than or equal to 0.04%, a silicon content of less than or equal to 0.03%, a phosphorus content of less than or equal to 0.02%, a sulfur content of less than or equal to 0.02%, and a manganese content of 0.15~0.35%.

[0038] This invention also provides a method for preparing flux-cored welding wire for wind turbine blade overlay welding, comprising the following steps:

[0039] Weigh each raw material and then dry it.

[0040] The dried raw materials are mixed evenly to obtain a core material mixture;

[0041] Carbon steel strip is rolled into a U-shaped groove;

[0042] The flux-cored material mixture is filled into a U-shaped groove, and then the openings of the U-shaped groove are butt-welded together to obtain the first welding wire;

[0043] The first welding wire is further rolled to reduce its diameter and then drawn into a wire drawing machine to a preset diameter to obtain the flux-cored welding wire for the wind turbine blade.

[0044] In one example of the preparation method of the wear-resistant flux-cored welding wire of the present invention, each raw material is dried at 190±5℃ and kept at that temperature for 60~100 minutes, and then cooled to room temperature before being removed from the furnace to obtain the dried raw materials.

[0045] In one example of the preparation method of the wear-resistant flux-cored welding wire of the present invention, high-frequency welding technology is used to weld the opening of the U-shaped groove together.

[0046] Different proportions of the above raw materials can constitute different embodiments, as shown in the following examples:

[0047] Example 1

[0048] Mass percentage of each component in the core material: high carbon ferrochrome: 76%, manganese silicon alloy: 5.8%, silicon carbide: 3%, ferrochrome carbide: 3.7%, ferrotitanium: 0.9%, graphite: 5.2%, ferrosilicon: 1.7%, quartz: 0.7%, cobalt powder: 3%.

[0049] The method for fabricating flux-cored welding wire for wind turbine blades using the above-mentioned flux-cored material includes the following steps:

[0050] Weigh each raw material and then dry it.

[0051] The dried raw materials are mixed evenly to obtain a core material mixture;

[0052] The carbon steel strip is cut to a width of 14mm, cleaned, and then rolled into a U-shaped channel;

[0053] The flux-cored material mixture is filled into a U-shaped groove, and then the openings of the U-shaped groove are butt-welded together to obtain the first welding wire. The mass of the flux-cored material mixture is 14% of the sum of the mass of the flux-cored material mixture and the mass of the steel strip sheath.

[0054] The first welding wire is further rolled to reduce its diameter and then drawn into a wire drawing machine to a diameter of 1.2 mm to obtain the flux-cored welding wire for the wind turbine blade.

[0055] In one example of the preparation method of the flux-cored welding wire for wind turbine blade overlay of the present invention, each raw material is dried at 190°C and kept at that temperature for 100 minutes, and then cooled to room temperature before being removed from the furnace to obtain the dried raw materials.

[0056] In one example of the preparation method of the flux-cored welding wire for wind turbine blade overlay of the present invention, high-frequency welding technology is used to weld the opening of the U-shaped groove together.

[0057] Example 2

[0058] Mass percentage of each component in the core material: high carbon ferrochrome: 75%, manganese silicon alloy: 4%, silicon carbide: 6%, ferrochrome carbide: 2%, ferrotitanium: 1%, graphite: 6%, ferrosilicon: 1.4%, quartz: 0.6%, cobalt powder: 4%.

[0059] The method for fabricating flux-cored welding wire for wind turbine blades using the above-mentioned flux-cored material includes the following steps:

[0060] Weigh each raw material and then dry it.

[0061] The dried raw materials are mixed evenly to obtain a core material mixture;

[0062] The carbon steel strip is cut to a width of 14mm, cleaned, and then rolled into a U-shaped channel;

[0063] The flux-cored material mixture is filled into a U-shaped groove, and then the openings of the U-shaped groove are butt-welded together to obtain the first welding wire. The mass of the flux-cored material mixture is 15% of the sum of the mass of the flux-cored material mixture and the mass of the steel strip outer sheath.

[0064] The first welding wire is further rolled to reduce its diameter and then drawn into a wire drawing machine to a diameter of 1.4 mm to obtain the flux-cored welding wire for the wind turbine blade.

[0065] In one example of the preparation method of the flux-cored welding wire for wind turbine blade overlay of the present invention, each raw material is dried at 195°C and kept at that temperature for 80 minutes, and then cooled to room temperature before being removed from the furnace to obtain the dried raw materials.

[0066] In one example of the preparation method of the flux-cored welding wire for wind turbine blade overlay of the present invention, high-frequency welding technology is used to weld the opening of the U-shaped groove together.

[0067] Example 3

[0068] Mass percentage of each component in the core material: high carbon ferrochrome: 74%, manganese silicon alloy: 5%, silicon carbide: 4%, ferrochrome carbide: 3.4%, ferrotitanium: 1.3%, graphite: 5%, ferrosilicon: 1.4%, quartz: 0.9%, cobalt powder: 5%.

[0069] The method for fabricating flux-cored welding wire for wind turbine blades using the above-mentioned flux-cored material includes the following steps:

[0070] Weigh each raw material and then dry it.

[0071] The dried raw materials are mixed evenly to obtain a core material mixture;

[0072] The carbon steel strip is cut to a width of 14mm, cleaned, and then rolled into a U-shaped channel;

[0073] The flux-cored material mixture is filled into a U-shaped groove, and then the openings of the U-shaped groove are butt-welded together to obtain the first welding wire. The mass of the flux-cored material mixture is 16% of the sum of the mass of the flux-cored material mixture and the mass of the steel strip outer sheath.

[0074] The first welding wire is further rolled to reduce its diameter and then drawn into a wire drawing machine to a diameter of 1.6 mm to obtain the flux-cored welding wire for the wind turbine blade.

[0075] In one example of the preparation method of the flux-cored welding wire for wind turbine blade overlay of the present invention, each raw material is dried at 190°C and kept at that temperature for 60 minutes, and then cooled to room temperature before being removed from the furnace to obtain the dried raw materials.

[0076] In one example of the preparation method of the flux-cored welding wire for wind turbine blade overlay of the present invention, high-frequency welding technology is used to weld the opening of the U-shaped groove together.

[0077] Example 4

[0078] Mass percentage of each component in the core material: high carbon ferrochrome: 70%, manganese silicon alloy: 8%, silicon carbide: 3.7%, ferrochrome carbide: 7%, ferrotitanium: 0.8%, graphite: 5.4%, ferrosilicon: 1.3%, quartz: 0.6%, cobalt powder: 3.2%.

[0079] The method for fabricating flux-cored welding wire for wind turbine blades using the above-mentioned flux-cored material includes the following steps:

[0080] Weigh each raw material and then dry it.

[0081] The dried raw materials are mixed evenly to obtain a core material mixture;

[0082] The carbon steel strip is cut to a width of 14mm, cleaned, and then rolled into a U-shaped channel;

[0083] The flux-cored material mixture is filled into a U-shaped groove, and then the openings of the U-shaped groove are butt-welded together to obtain the first welding wire. The mass of the flux-cored material mixture is 17% of the sum of the mass of the flux-cored material mixture and the mass of the steel strip outer sheath.

[0084] The first welding wire is further rolled to reduce its diameter and then drawn into a wire drawing machine to a diameter of 1.7 mm to obtain the flux-cored welding wire for the wind turbine blade.

[0085] In one example of the preparation method of the flux-cored welding wire for wind turbine blade overlay of the present invention, each raw material is dried at 185°C and kept at that temperature for 80 minutes, and then cooled to room temperature before being removed from the furnace to obtain the dried raw materials.

[0086] In one example of the preparation method of the flux-cored welding wire for wind turbine blade overlay of the present invention, high-frequency welding technology is used to weld the opening of the U-shaped groove together.

[0087] The flux-cored welding wire for wind turbine blade overlay of the present invention was used to conduct various welding tests on the welding wires obtained in Examples 1 to 4 above, according to relevant standards.

[0088] The mechanical properties of the weld metal from the welding tests of each embodiment are shown in Table 1 below:

[0089] Table 1 Chemical composition of weld metal

[0090]

[0091] The hardness of the weld metal in the welding experiments of each embodiment is shown in Table 2 below:

[0092]

[0093] The wear resistance of the weld metal in the welding tests of each embodiment is shown in Table 3 below:

[0094]

[0095] The welding parameters for the welding tests in each embodiment are shown in Table 4 below:

[0096] Table 4 Welding parameters

[0097]

[0098] Various tests have shown that the weld metal of the wear-resistant flux-cored welding wire of the present invention has high hardness and wear resistance, and its performance is superior to that of the base material used for wind turbine blades.

[0099] This invention relates to a wear-resistant flux-cored welding wire and its preparation method, resulting in a weld metal primarily composed of martensite and alloy carbides. This metal exhibits excellent resistance to particle wear, high temperature resistance, and high hardness, effectively extending the service life of wind turbine blades. Furthermore, it is suitable for various flat and horizontal welding methods and has good compatibility with the welding positions on wind turbine blades. The hardness (HRC) of the single-layer weld metal is not less than 55, with minimal wear loss and a long service life. Therefore, this invention effectively overcomes some practical problems in the prior art, thus possessing high utilization value and practical significance. The above embodiments are merely illustrative of the principles and effects of this invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this invention should still be covered by the claims of this invention.

Claims

1. A wind turbine blade cladding flux cored wire, characterized in that, The steel belt sheath and the core material, the core material is filled in the steel belt sheath, the core material is composed of the following raw materials in mass percentage: High-carbon chromium iron: 70-78%, manganese-silicon alloy: 4-8%, silicon carbide: 3-6%, chromium iron carbide: 2-7%, ferrotitanium: 0.8-1.3%, graphite: 5.2-6.0%, ferrosilicon: 1.3-1.7%, quartz: 0.6-0.9%, cobalt powder: 3-5%.

2. The wind turbine blade cladding flux cored wire of claim 1, wherein, The mass of the core material is 14-17% of the sum of the mass of the core material and the mass of the steel belt sheath.

3. The fan blade overlay flux-cored wire of claim 1, wherein, The particle size of each raw material in the core material is 60-100 mesh.

4. The wind turbine blade cladding flux cored wire of claim 1, wherein, The diameter of the core welding wire is 1.2-1.6 mm.

5. The fan blade overlay flux-cored wire of claim 1 wherein, The steel belt sheath is a carbon steel belt.

6. The wind turbine blade cladding flux cored wire of claim 5, wherein, In the carbon steel belt, the carbon content is less than or equal to 0.04%, the silicon content is less than or equal to 0.03%, the phosphorus content is less than or equal to 0.02%, the sulfur content is less than or equal to 0.02%, and the manganese content is 0.15-0.35%.

7. A method of making a fan blade overlay flux-cored welding wire as claimed in any one of claims 5 to 6, characterised in that, The method comprises the following steps: After weighing each raw material, drying is performed; After drying each raw material, the raw materials are mixed uniformly to obtain a core material mixture; The carbon steel belt is rolled into a U-shaped groove; The core material mixture is filled into the U-shaped groove, and then the opening of the U-shaped groove is butt welded to obtain a first welding wire; After the first welding wire is continuously reduced in diameter and then enters a drawing machine to be drawn to a preset diameter, the fan blade surfacing core welding wire is obtained.

8. The method of claim 7, wherein the wind turbine blade overlay flux cored wire is prepared by the steps of: Each raw material is dried at 190±5℃ and kept for 60-100 minutes, and then taken out after being reduced to room temperature, to obtain dried raw materials.

9. The method of claim 7, wherein the wind turbine blade overlay flux cored wire is prepared by the steps of: The opening of the U-shaped groove is butt welded using high-frequency welding technology.

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