Low-carbon high-manganese flux-cored wire and preparation method thereof

Abstract

The application provides a low-carbon high-manganese flux-cored wire and a preparation method thereof, and relates to the field of welding materials.The low-carbon high-manganese flux-cored wire comprises a steel belt sheath and a core material, the core material is filled in the steel belt sheath, and the core material comprises the following raw materials in terms of mass percentage: 36-45% of rutile, 2-4% of ferrotitanium, 4-6% of aluminum powder, 5-7% of manganese-silicon alloy, 6-8% of vanadium iron, 1-3% of nickel powder, 3-5% of molybdenum powder, 2-4% of sodium fluoride powder, 0.5-1% of rare earth ferrosilicon, 0.5-1% of high-boron iron, 2-3% of graphite, and the balance of atomized iron powder.The low-carbon high-manganese flux-cored wire and the preparation method thereof have the advantages that the flux-cored wire deposited metal has similar composition to that of 20Mn23Al, good weldability and excellent crack resistance, the matching of various elements in the flux-cored wire deposited metal also reduces the magnetic permeability, and the flux-cored wire is very suitable for the welding of 20Mn23Al structure, and has the advantages of low cost and long service life.

Description

Technical Field

[0001] This invention relates to the field of welding materials, specifically to a low-carbon, high-manganese flux-cored welding wire and its preparation method. Background Technology

[0002] In the manufacture of large transformers, 20Mn23Al is widely used due to its stable antimagnetic properties and low price. It is mainly used in components requiring non-magnetic properties, such as transformer core tie rods, clamps, tank walls, and flanges. Because of its low permeability and high resistivity, eddy current losses in the magnetic field are minimal during transformer operation, thus improving the transformer's performance and lifespan. However, currently, there are no dedicated welding materials specifically designed for 20Mn23Al, and the weld metal from ordinary welding materials cannot meet the crack resistance and antimagnetic properties of 20Mn23Al. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the present invention provides a low-carbon high-manganese flux-cored welding wire and its preparation method, so as to improve the technical problem that there is currently no welding material compatible with 20Mn23Al.

[0004] To achieve the above and other related objectives, the present invention provides a low-carbon, high-manganese flux-cored welding wire, comprising a steel strip sheath and a flux-cored material, wherein the flux-cored material is filled within the steel strip sheath, and the flux-cored material comprises the following raw materials by mass percentage based on the total mass of the flux-cored material:

[0005] Rutile 36-45%, ferrotitanium 2-4%, aluminum powder 4-6%, silicon manganese alloy 5-7%, ferrovanadium 6-8%, nickel powder 1-3%, molybdenum powder 3-5%, sodium fluoride powder 2-4%, rare earth ferrosilicon 0.5-1%, high boron ferrophosphate 0.5-1%, graphite 2-3%, with the balance being atomized iron powder.

[0006] In one example of the low-carbon, high-manganese flux-cored welding wire of the present invention, the rutile contains 95% or more titanium dioxide, 0.01% or less sulfur, and 0.01% or less phosphorus; the ferrotitanium contains 37-42% titanium and 5% silicon; the rare-earth ferrosilicon contains 30-35% rare earth and 40-45% silicon; the nickel powder contains 99% or more nickel, 0.01% or less sulfur, and 0.03% carbon; the sodium fluoride powder contains 98% or more sodium fluoride; and the aluminum powder contains 97% or more aluminum, 0.5% silicon, and 0.5% iron. The manganese-silicon alloy contains 62-67% manganese, 20-23% silicon, 0.8% carbon, 0.04% sulfur, and 0.1% phosphorus; the ferrovanadium contains 50% vanadium, 2% silicon, 2% aluminum, and 0.4% carbon; the molybdenum powder contains 99% molybdenum, 0.02% carbon, and 0.02% phosphorus; the high-boron ferrometallurgical contains 16% boron and 0.6% carbon; the graphite contains 99% carbon; and the atomized iron powder contains 98% iron.

[0007] In one example of the low-carbon, high-manganese flux-cored welding wire of the present invention, the particle size of each raw material in the flux-cored material is 60-100 mesh.

[0008] In an example of the low-carbon, high-manganese flux-cored welding wire of the present invention, the rutile has a particle size of 80 mesh, the ferrotitanium has a particle size of 80 mesh, the rare earth ferrosilicon has a particle size of 100 mesh, the nickel powder has a particle size of 60 mesh, the sodium fluoride powder has a particle size of 80 mesh, the aluminum powder has a particle size of 80 mesh, the manganese silicon alloy has a particle size of 60 mesh, the ferrovanadium has a particle size of 80 mesh, the molybdenum powder has a particle size of 60 mesh, the high-boron ferrometallurgical has a particle size of 60 mesh, the graphite has a particle size of 60 mesh, and the atomized iron powder has a particle size of 60 mesh.

[0009] In one example of the low-carbon high-manganese flux-cored welding wire of the present invention, the diameter of the low-carbon high-manganese flux-cored welding wire is 1.2-1.6 mm.

[0010] In one example of the low-carbon high-manganese flux-cored welding wire of the present invention, the mass of the flux-cored material is 14-16% of the sum of the mass of the flux-cored material and the mass of the steel strip sheath.

[0011] In one example of the low-carbon high-manganese flux-cored welding wire of the present invention, the outer sheath of the steel strip is a low-carbon high-manganese steel strip. Based on the total mass of the low-carbon high-manganese steel strip, the mass percentage of each component in the low-carbon high-manganese steel strip is as follows: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance is iron.

[0012] In one example of the low-carbon high-manganese flux-cored welding wire of the present invention, the thickness of the low-carbon high-manganese steel strip is 0.8-1.2 mm.

[0013] This invention also provides a method for preparing a low-carbon, high-manganese flux-cored welding wire, comprising the following steps:

[0014] S1. Weigh each raw material and then dry it;

[0015] S2. Mix the dried raw materials evenly to obtain a core material mixture;

[0016] S3. Roll the low-carbon high-manganese steel strip into a U-shaped groove;

[0017] S4. Fill the above-mentioned flux-cored material mixture into the U-shaped groove, and then roll the U-shaped groove into an oxygen mold groove to obtain the first welding wire;

[0018] S5. 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 low-carbon high-manganese flux-cored welding wire.

[0019] In one example of the preparation method of the low-carbon high-manganese flux-cored welding wire of the present invention, each raw material is dried at 170±5℃ and kept at that temperature for 100-120 minutes, and then cooled to room temperature before being removed from the furnace to obtain the dried raw materials.

[0020] This invention relates to a low-carbon, high-manganese flux-cored welding wire and its preparation method. The flux-cored welding wire has a fused metal composition similar to that of 20Mn23Al, and also exhibits good weldability and excellent crack resistance. The combination of elements among the fused metals of the flux-cored welding wire also has the effect of reducing magnetic permeability, making it very suitable for welding 20Mn23Al structures. It also has the advantages of low cost and long service life. Detailed Implementation

[0021] 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.

[0022] 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.

[0023] 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.

[0024] This invention provides a low-carbon, high-manganese flux-cored welding wire, comprising a steel strip sheath and a flux-cored material. The flux-cored material is filled inside the steel strip sheath. Based on the total mass of the flux-cored material, the flux-cored material comprises the following raw materials by mass percentage: rutile 36-45%, with rutile being the main slag-forming agent and arc-stabilizing agent.

[0025] 2-4% ferrotitanium (TIF) is mainly used to improve the toughness of weld metal. It also has the functions of deoxidation, arc stabilization, promoting the transition of molten droplets in a mist-like manner, and achieving fine and bright weld formation. At the same time, ferrotitanium can also promote the formation of acicular ferrite, refine grains, increase grain boundary area, improve the mechanical properties of materials, and has a good slag-forming effect.

[0026] Aluminum powder 4-6%, the main function of aluminum powder is deoxidation and denitrification, to avoid the formation of carbon-oxygen and nitrogen pores inside the weld.

[0027] Manganese silicon alloy 5-7%, manganese silicon alloy is the main deoxidizer, increases the strength and crack resistance of weld metal, improves the elongation of weld, and also has a carburizing effect, and helps to improve low temperature impact toughness.

[0028] Ferrovanadium (6-8%) plays a role in precipitation strengthening. The vanadium in ferrovanadium can refine the grains, thereby improving the strength and toughness of the weld metal.

[0029] Nickel powder 1-3% is used to reduce proeutectoid ferrite in weld metal and increase acicular ferrite;

[0030] Molybdenum powder (3-5%) is used to improve the hardenability of weld metal, enhance the solid solution effect, and suppress temper brittleness.

[0031] Sodium fluoride powder 2-4% is used to reduce the diffusible hydrogen content in the weld metal. At the same time, the sodium fluoride powder content should not be too high to prevent reducing the stability of the weld.

[0032] Rare earth ferrosilicon (0.5-1%) can alter the size, shape, and distribution of non-metallic inclusions in weld metal, thereby improving the crack resistance and toughness of the weld metal.

[0033] 0.5-1% high boron iron is used to refine grains and improve the toughness of weld metal.

[0034] Graphite 2-3% can increase the conductivity of low-carbon, high-manganese flux-cored welding wire, lower the melting point, and improve welding efficiency.

[0035] The remainder is atomized iron powder. The spherical particle characteristics of the atomized iron powder can improve the overall flowability of the flux preparation, ensuring uniform filling and molding of the flux. The addition of atomized iron powder can effectively improve the conductivity of the flux core, increase the welding wire deposition efficiency, and ensure good welding processability.

[0036] In one example of the low-carbon, high-manganese flux-cored welding wire of the present invention, the rutile contains 95% or more titanium dioxide, 0.01% or less sulfur, and 0.01% or less phosphorus. The melting point of titanium dioxide is 1850°C. The higher content of rutile in the flux-cored material can increase the solidification rate of the slag, which is beneficial for all-position welding. Some titanium dioxide is also distributed in the weld in the form of tiny oxides, which promotes the grain refinement of the weld metal.

[0037] The titanium-iron contains 37-42% titanium and 5% silicon. The titanium element can form stable carbides, avoiding the precipitation of carbon-rich carbides at the grain boundaries and preventing intergranular corrosion.

[0038] The rare earth ferrosilicon contains 30-35% rare earth elements and 40-45% silicon. By adding rare earth elements that have a strong affinity for oxygen, sulfur, and silicon, the size, shape, and quantity of inclusions are altered, thereby mitigating their detrimental effect on toughness. For example, after adding rare earth elements, it was found that the inclusions became spheroidized, refined, and more uniform in size, which also helps to reduce the austenite grain size.

[0039] The nickel powder contains 99% or more nickel, 0.01% or less sulfur, and 0.03% or less carbon. The presence of nickel ensures that the deposited metal has an austenitic structure.

[0040] The sodium fluoride powder contains 98% or more sodium fluoride. The F- in the sodium fluoride powder reacts with the H2 oxygen in the powder to generate gases such as HF, which reduces the diffusion of hydrogen in the weld.

[0041] The aluminum powder contains 97% or more aluminum, 0.5% or less silicon, and 0.5% or less iron. During the welding process, aluminum reacts with oxygen to form oxides and readily combines with nitrogen to form stable aluminum-nitrogen inclusions that are insoluble in liquid metal. These inclusions then form trace amounts of slag on the weld surface.

[0042] The manganese-silicon alloy contains 62-67% manganese, 20-23% silicon, less than or equal to 0.8% carbon, less than or equal to 0.04% sulfur, and less than or equal to 0.1% phosphorus.

[0043] The vanadium-iron contains 50% or more vanadium, 2% or less silicon, 2% or less aluminum, and 0.4% carbon. Vanadium is an element that promotes the formation of ferrite and has a strong binding force with carbon, nitrogen, and oxygen, which can form corresponding compounds with strong stability, playing a role in precipitation strengthening. In addition, the addition of a small amount of vanadium can refine the grains, thereby improving strength and toughness.

[0044] The molybdenum powder contains 99% or more molybdenum, 0.02% or less carbon, and 0.02% or less phosphorus. Molybdenum can eliminate or reduce temper brittleness caused by other alloying elements, which can not only enhance the hardenability and ductility of the weld metal, but also greatly improve the impact toughness of the weld metal.

[0045] The high-boron iron contains 16% or more boron and 0.6% or less carbon; the graphite contains 99% or more carbon.

[0046] The iron content in the atomized iron powder is greater than or equal to 98%.

[0047] In an example of the low-carbon, high-manganese flux-cored welding wire of the present invention, the particle size of each raw material in the flux-cored material is 60-100 mesh, wherein the rutile particle size is 80 mesh, and the rutile particle satisfaction rate is that the number of particles passing through 80 mesh is greater than or equal to 99% of the total; the ferrotitanium particle size is 80 mesh, and the ferrotitanium particle satisfaction rate is that the number of particles passing through 80 mesh is greater than or equal to 99% of the total; the rare earth ferrosilicon particle size is 100 mesh, and the rare earth ferrosilicon particle satisfaction rate is that the number of particles passing through 100 mesh is greater than or equal to 95% of the total; the nickel powder particle size is 60 mesh, and the nickel powder particle satisfaction rate is that the number of particles passing through 60 mesh is greater than or equal to 99% of the total; the sodium fluoride powder particle size is 80 mesh, and the sodium fluoride powder particle satisfaction rate is that the number of particles passing through 80 mesh is greater than or equal to 95% of the total; the aluminum powder particle size is 80 mesh, and the aluminum powder particle satisfaction rate is that the number of particles passing through 80 mesh is greater than or equal to 95% of the total; The following conditions are met: The particle size of the 0-mesh material is greater than or equal to 95% of the total; the particle size of the manganese silicon alloy is 60 mesh, and the percentage of manganese silicon alloy particles passing through the 60-mesh material is greater than or equal to 95% of the total; the particle size of the vanadium iron is 80 mesh, and the percentage of vanadium iron particles passing through the 80-mesh material is greater than or equal to 95% of the total; the particle size of the molybdenum powder is 60 mesh, and the percentage of molybdenum powder particles passing through the 60-mesh material is greater than or equal to 95% of the total; the particle size of the high-boron iron is 60 mesh, and the percentage of high-boron iron particles passing through the 60-mesh material is greater than or equal to 95% of the total; the particle size of the graphite is 60 mesh, and the percentage of graphite particles passing through the 60-mesh material is greater than or equal to 98% of the total; the particle size of the atomized iron powder is 60 mesh, and the percentage of atomized iron powder particles passing through the 60-mesh material is greater than or equal to 95% of the total.

[0048] In one example of the low-carbon high-manganese flux-cored welding wire of the present invention, the diameter of the low-carbon high-manganese flux-cored welding wire is 1.2-1.6 mm.

[0049] In one example of the low-carbon high-manganese flux-cored welding wire of the present invention, the mass of the flux-cored material is 14-16% of the sum of the mass of the flux-cored material and the mass of the steel strip sheath.

[0050] In one example of the low-carbon, high-manganese flux-cored welding wire of the present invention, the outer sheath of the steel strip is a low-carbon, high-manganese steel strip. Based on the total mass of the low-carbon, high-manganese steel strip, the mass percentages of each component in the low-carbon, high-manganese steel strip are as follows: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance being iron. By transferring the manganese from the low-carbon, high-manganese steel strip into the weld metal, the required composition content of the weld is achieved.

[0051] In one example of the low-carbon high-manganese flux-cored welding wire of the present invention, the thickness of the low-carbon high-manganese steel strip is 1 mm.

[0052] This invention also provides a method for preparing a low-carbon, high-manganese flux-cored welding wire, comprising the following steps:

[0053] Weigh each raw material and then dry it.

[0054] The dried raw materials are mixed evenly to obtain a core material mixture;

[0055] Low-carbon, high-manganese steel strip is rolled into a U-shaped groove;

[0056] The above-mentioned flux-cored material mixture is filled into a U-shaped groove, and then the U-shaped groove is rolled into an oxygen mold groove to obtain the first welding wire;

[0057] 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 low-carbon high-manganese flux-cored welding wire.

[0058] In one example of the preparation method of the low-carbon high-manganese flux-cored welding wire of the present invention, each raw material is dried at 170±5℃ and kept at that temperature for 100-120 minutes, and then cooled to room temperature before being removed from the furnace to obtain the dried raw materials.

[0059] Different proportions of the above raw materials can constitute different embodiments, as shown in the following examples:

[0060] Example 1

[0061] Mass percentage of each component in the core material: rutile 36%, ferrotitanium 4%, aluminum powder 6%, manganese silicon alloy 6%, ferrovanadium 7%, nickel powder 1%, molybdenum powder 4%, sodium fluoride powder 3%, rare earth ferrosilicon 1%, high boron iron 0.5%, graphite 2.5%, and atomized iron powder 29%.

[0062] The method for manufacturing low-carbon, high-manganese flux-cored welding wire using the above-mentioned flux-cored material includes the following steps:

[0063] The weighed raw materials were dried at 165℃ and kept at that temperature for 110 minutes. Then they were cooled to room temperature and removed from the oven to obtain the dried raw materials.

[0064] The dried raw materials are mixed evenly to obtain a core material mixture;

[0065] Low-carbon, high-manganese steel strip is rolled into a U-shaped groove;

[0066] The above-mentioned flux-cored material mixture is filled into a U-shaped groove, the mass of which accounts for 14% of the total mass of the flux-cored material mixture and the U-shaped groove. Then, the U-shaped groove is rolled into an oxygen mold groove to obtain the first welding wire.

[0067] The first welding wire is further rolled to reduce its diameter and then drawn into a wire drawing machine to a preset diameter of 1.2 mm to obtain the low-carbon high-manganese flux-cored welding wire.

[0068] Example 2

[0069] Mass percentage of each component in the core material: rutile 38%, ferrotitanium 2%, aluminum powder 6%, manganese silicon alloy 7%, ferrovanadium 6%, nickel powder 3%, molybdenum powder 5%, sodium fluoride powder 4%, rare earth ferrosilicon 0.5%, high boron ferrophosphate 0.5%, graphite 2%, and atomized iron powder 26%.

[0070] The method for manufacturing low-carbon, high-manganese flux-cored welding wire using the above-mentioned flux-cored material includes the following steps:

[0071] The weighed raw materials were dried at 170℃ and kept at that temperature for 100 minutes, and then cooled to room temperature before being removed from the oven to obtain the dried raw materials.

[0072] The dried raw materials are mixed evenly to obtain a core material mixture;

[0073] Low-carbon, high-manganese steel strip is rolled into a U-shaped groove;

[0074] The above-mentioned flux-cored material mixture is filled into a U-shaped groove, the mass of which accounts for 14% of the total mass of the flux-cored material mixture and the U-shaped groove. Then, the U-shaped groove is rolled into an oxygen mold groove to obtain the first welding wire.

[0075] The first welding wire is further rolled to reduce its diameter and then drawn into a wire drawing machine to a preset diameter of 1.4 mm to obtain the low-carbon high-manganese flux-cored welding wire.

[0076] Example 3

[0077] Mass percentage of each component in the core material: rutile 42%, ferrotitanium 3%, aluminum powder 5%, manganese silicon alloy 5%, ferrovanadium 8%, nickel powder 2%, molybdenum powder 3%, sodium fluoride powder 2%, rare earth ferrosilicon 1%, high boron ferrophosphate 1%, graphite 3%, and atomized iron powder 25%.

[0078] The method for manufacturing low-carbon, high-manganese flux-cored welding wire using the above-mentioned flux-cored material includes the following steps:

[0079] The weighed raw materials were dried at 175℃ and kept at that temperature for 120 minutes. Then they were cooled to room temperature and removed from the oven to obtain the dried raw materials.

[0080] The dried raw materials are mixed evenly to obtain a core material mixture;

[0081] Low-carbon, high-manganese steel strip is rolled into a U-shaped groove;

[0082] The above-mentioned flux-cored material mixture is filled into a U-shaped groove, the mass of which accounts for 15% of the total mass of the flux-cored material mixture and the U-shaped groove. Then, the U-shaped groove is rolled into an oxygen mold groove to obtain the first welding wire.

[0083] The first welding wire is further rolled to reduce its diameter and then drawn into a wire drawing machine to a preset diameter of 1.6 mm to obtain the low-carbon high-manganese flux-cored welding wire.

[0084] Example 4

[0085] Mass percentage of each component in the core material: rutile 45%, ferrotitanium 3%, aluminum powder 4%, manganese silicon alloy 5%, ferrovanadium 8%, nickel powder 1%, molybdenum powder 3%, sodium fluoride powder 3%, rare earth ferrosilicon 0.5%, high boron ferrophosphate 0.5%, graphite 2%, and atomized iron powder 25%.

[0086] The method for manufacturing low-carbon, high-manganese flux-cored welding wire using the above-mentioned flux-cored material includes the following steps:

[0087] The weighed raw materials were dried at 170℃ and kept at that temperature for 120 minutes. Then they were cooled to room temperature and removed from the oven to obtain the dried raw materials.

[0088] The dried raw materials are mixed evenly to obtain a core material mixture;

[0089] Low-carbon, high-manganese steel strip is rolled into a U-shaped groove;

[0090] The above-mentioned flux-cored material mixture is filled into a U-shaped groove, the mass of which accounts for 16% of the total mass of the flux-cored material mixture and the U-shaped groove. Then, the U-shaped groove is rolled into an oxygen mold groove to obtain the first welding wire.

[0091] The first welding wire is further rolled to reduce its diameter and then drawn into a wire drawing machine to a preset diameter of 1.6 mm to obtain the low-carbon high-manganese flux-cored welding wire.

[0092] The chemical composition of the low-carbon, high-manganese steel strips in Examples 1-4 above is shown in Table 1 below:

[0093] Table 1. Chemical Composition of Low-Carbon High-Manganese Steel Strip (%)

[0094]

[0095] The low-carbon, high-manganese flux-cored welding wire of the present invention was used to conduct various welding tests on the welding wires obtained in Examples 1-4 above, according to relevant standards. The welding shielding gas was carbon-oxygen 2.

[0096] The welding parameters and flaw detection results of the welding tests in each embodiment are shown in Table 2 below:

[0097] Table 2 Welding parameters and flaw detection results

[0098] Example Welding current (A) Welding voltage (V) Welding speed (mm / min) flaw detection 1 160-180 26-27 400-450 qualified 2 180-220 28-29 500-550 qualified 3 200-260 29-30 600-650 qualified 4 200-260 29-30 600-650 qualified

[0099] The mechanical properties of the weld metal from the welding tests of each embodiment are shown in Table 3 below:

[0100] Table 3 Mechanical properties of deposited metal

[0101] Example Tensile strength (Rm / MPa) Elongation (A / %) 1 745 45 2 733 44 3 725 46 4 739 45

[0102] The results of the three impact energy tests on the weld metal in each embodiment are shown in Table 4 below:

[0103] Table 4. Results of Impact Energy Test of Deposited Metal

[0104]

[0105] This invention relates to a low-carbon, high-manganese flux-cored welding wire and its preparation method. By increasing the manganese content of the weld metal to expand the austenitic phase region, and appropriately adding nickel, the microstructure of the weld metal is ensured to be austenitic. The combined effect of these elements results in an entirely austenitic weld microstructure, reducing weld magnetic permeability. Phosphorus and sulfur content are controlled to ensure the mechanical properties of the weld metal. Furthermore, the addition of sodium fluoride powder removes diffusible hydrogen from the weld, improving its crack resistance. The flux-cored welding wire has a weld composition similar to that of 20Mn23Al, while exhibiting good weldability, excellent crack resistance, and antimagnetic properties. It is highly suitable for welding 20Mn23Al structures, and also offers the advantages of low cost and 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 change 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 shall still be covered by the claims of this invention.

Claims

1. A low carbon high manganese flux cored wire characterized by, The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron.

2. The low carbon high manganese flux cored wire of claim 1, wherein, The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron.

3. The low carbon high manganese flux cored wire of claim 1 wherein, The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron.

4. The low carbon high manganese flux cored wire of claim 3, wherein, The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron.

5. The low carbon high manganese flux cored wire of claim 1 wherein, The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron.

6. The low carbon high manganese flux cored wire of claim 1 wherein, The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron.

7. The low carbon high manganese flux cored wire of claim 1 wherein, The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron.

8. A method of producing the low-carbon high-manganese flux-cored wire according to any one of claims 1 to 7, characterized by, The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron.

9. The method of making a low carbon high manganese flux cored wire as claimed in claim 8, wherein, The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%, phosphorus less than or equal to 0.025%, nickel 2-3%, and the balance of iron. The low-carbon high-manganese steel belt includes the following components by mass percentage: carbon less than or equal to 0.04%, manganese less than or equal to 23-25%, silicon less than or equal to 0.03%,

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