A flux-cored wire for high manganese steel independent of nickel powder and a method for manufacturing the same

Abstract

The application discloses a flux-cored wire for high manganese steel independent of nickel powder and a preparation method thereof, and belongs to the technical field of the flux-cored wire.The flux-cored wire comprises a stainless steel strip and a core powder filled in the stainless steel strip, and the core powder comprises the following components in percentage by mass: 35%-45% of manganese powder, 1%-2% of aluminum-magnesium alloy powder, 0.5%-1.75% of niobium powder, 0.5%-1% of cerium oxide, 2%-4% of calcium fluoride, 1%-2% of cryolite, 1.5%-3% of magnesium carbonate, 1%-2.5% of silicon-calcium-barium composite agent, 25%-35% of manganese nitride, 1%-2% of graphite, and the balance of iron powder; and the content of Ni in the stainless steel strip is 8%-11%. The application effectively solves the technical problem that the weld strength and toughness of the conventional stainless steel wire are difficult to be considered in a deep cold environment, realizes the stabilization of the weld structure in the deep cold environment, and provides an effective solution for welding liquefied natural gas equipment, aerospace fuel storage tanks and other extreme environment structures.

Description

Technical Field

[0001] This invention belongs to the field of flux-cored welding wire technology, specifically relating to a flux-cored welding wire for high-manganese steel that does not rely on nickel powder and its preparation method. Background Technology

[0002] In today's era, liquefied natural gas (LNG), as a clean fossil fuel, occupies a crucial position in the global energy structure. The LNG industry chain, encompassing ocean-going vessels, land-based and offshore receiving terminals, and terminal storage tanks, must be able to safely withstand extremely low temperatures of around -196°C, requiring high strength, excellent toughness, and good weldability at these extreme temperatures. Beyond the LNG industry, the coal chemical, air separation, and aerospace sectors also have significant demands for the safe and efficient storage of cryogenic media. The supply of clean energy and the development of cutting-edge technologies have long relied on superior and stable cryogenic performance.

[0003] Currently, 9Ni steel is the standard steel used globally for cryogenic pressure vessels rated at -196℃. However, in practical applications, 9Ni steel welding materials present several significant challenges. The most prominent and common issue is its susceptibility to hot cracking. Nickel forms a low-melting-point eutectic with sulfur and phosphorus, leading to grain boundary separation and solidification cracks under welding stress. This reaction necessitates extremely stringent control over the composition of both the base metal and welding materials during 9Ni steel welding. Secondly, while 9Ni steel is ferromagnetic at room temperature, some areas lose their magnetism during welding, causing severe arc blow and significantly impacting weld quality. Furthermore, nickel resources are primarily imported and expensive, resulting in high material costs for 9Ni steel. The nickel-based alloy welding materials used in these vessels contain over 60% nickel, costing several times more than 9Ni steel itself, thus drastically increasing the overall cost of the welded structure.

[0004] Furthermore, when welding 9Ni steel, the welding process must be extremely strictly controlled to ensure the low-temperature toughness of the weld and heat-affected zone. High requirements are placed on preheating and interpass temperatures, conditions that are difficult to guarantee in harsh environments. At the same time, stringent process parameters mean that welding speed cannot be too fast, requiring more welding passes and a longer construction period, directly increasing labor and time costs.

[0005] To overcome the bottleneck in welding consumables for 9Ni steel, high-manganese steel welding consumables have emerged. High-manganese steel possesses a stable microstructure and good toughness at low temperatures, along with extremely strong work hardening ability and higher safety under impact, making it an ideal candidate to replace existing 9Ni steel welding consumables. However, there are still many problems with welding with existing high-manganese steel consumables that need to be solved. First, high-manganese steel austenitic welds share the same high hot-cracking sensitivity as nickel-based welds, being sensitive to impurities and silicon segregation, and exhibiting a high tendency for solidification cracking. Second, high-manganese steel is prone to the precipitation of carbides or other brittle phases during welding, which severely impairs the low-temperature toughness of the weld.

[0006] In summary, developing a high-performance welding solution that can effectively overcome the high thermal cracking sensitivity of high-manganese austenitic steel weld metal; ensure that the weld metal can still obtain a stable and excellent austenitic structure and good impact toughness in an ultra-low temperature environment of -196℃; improve welding processes and reduce excessive reliance on operator skills; and provide a flux-cored welding wire for high-manganese steel with significantly lower cost compared to traditional nickel-based welding materials, which can promote the engineering application of ultra-low temperature high-manganese steel, has become an urgent technical need in this field. Summary of the Invention

[0007] In view of the technical problems of high manganese steel welding pointed out in the background art, the present invention aims to provide a flux-cored welding wire for high manganese steel that does not rely on nickel powder and its preparation method, which has the characteristics of low cost, good adaptability to welding process, and enables the weld to still exhibit excellent impact toughness in extremely low temperature environment.

[0008] The first aspect of this invention provides a flux-cored welding wire for high-manganese steel that does not rely on nickel powder, comprising a stainless steel strip and flux powder filled within the stainless steel strip; wherein the flux powder, by mass percentage, comprises: 35%-45% metallic manganese powder, 1%-2% aluminum-magnesium alloy powder, 0.5%-1.75% metallic niobium powder, 0.5%-1% cerium oxide, 2%-4% calcium fluoride, 1%-2% cryolite, 1.5%-3% magnesium carbonate, 1%-2.5% silicon-calcium-barium composite agent, 25%-35% manganese nitride, 1%-2% graphite, and the balance being iron powder.

[0009] The manganese powder in question has a purity of ≥99.5%.

[0010] The aluminum-magnesium alloy powder has an active metal purity of ≥98% and an aluminum to magnesium content ratio of approximately 1:1. The aluminum-magnesium alloy powder primarily functions to deoxidize and fix nitrogen. Aluminum and magnesium can reduce the oxygen content in the molten pool immediately. Simultaneously, aluminum reacts with nitrogen to prevent nitrogen from accumulating and forming nitrogen pores due to oversaturation in the molten pool. It also reacts with cerium oxide to reduce cerium, thus refining the grain size.

[0011] The aforementioned silicon-calcium-barium composite agent, by mass percentage, contains 60%-70% Si, 15%-25% Ca, 10%-20% Ba, and trace amounts of unavoidable impurities. The silicon-calcium-barium composite agent has a low melting point and large particles, making it easier to polymerize and float in the molten pool. This improves the morphology of inclusions in the weld, thereby enhancing the weld's toughness and plasticity. The combined use of aluminum-magnesium alloy powder and the silicon-calcium-barium composite agent has a complementary effect, purifying the entire process from the arc zone and molten pool to the weld. This results in a weld free of porosity, with fewer inclusions, finer grains, achieving high toughness and excellent overall performance.

[0012] The niobium powder has a purity of ≥99.8% and is mainly used as a microalloying element to refine grains and strengthen the structure.

[0013] The cerium oxide mentioned has a purity of ≥99.9%. The reduction reaction between aluminum in the aluminum-magnesium alloy and cerium oxide ensures complete reaction of the cerium oxide, maximizing the recovery efficiency of cerium and fully realizing its grain refinement and microalloying effects. However, excessive aluminum may lead to coarse ferrite and reduced weld toughness; therefore, the preferred addition ratio of aluminum-magnesium alloy and cerium oxide in this invention is 2:1.

[0014] The calcium fluoride mentioned above has a purity of ≥97% and is mainly used as a slag-forming agent. It is necessary to control the impurity content in the powder and the moisture content of the powder to prevent moisture absorption.

[0015] The cryolite mentioned above has a purity of ≥98%. Cryolite can melt at lower temperatures and promote the dissolution of oxides. It can also effectively destroy the oxide film on the surface of the molten metal pool, making the slag easier to spread and peel off.

[0016] The magnesium carbonate described herein has a purity of ≥98%. Magnesium carbonate decomposes at high temperatures to produce gas, which can form a gas shield and also plays a role in stabilizing the arc. The magnesium oxide produced during its decomposition is an alkaline oxide that can coat the surface of the molten pool to provide slag protection. In this invention, magnesium carbonate and cryolite are added in a ratio of 1.5:1, achieving an optimal balance between gasification and slag formation, oxide film removal, and refining functions.

[0017] The manganese nitride, with Mn≥90% and N≈3%-5%, provides manganese while fixing nitrogen to ensure that nitrogen can be stably added to the weld.

[0018] The graphite has a purity of ≥98%, and the carbon content is precisely controlled to control the carbon equivalent and strength in the weld, thus preventing impurities from entering the weld.

[0019] Furthermore, the particle size of the above-mentioned powder is no greater than 80 mesh, and the content of particles smaller than 120 mesh does not exceed 10%.

[0020] Furthermore, the chemical composition of the stainless steel strip, by mass percentage, includes C 0.03%-0.10%, Si 1%-2%, Mn 0.8%-2%, Ni 8%-11%, Cr 18%-20%, P≤0.045%, S≤0.03%, with the balance being Fe and unavoidable impurities.

[0021] Furthermore, the stainless steel strip is made of S304 series steel, preferably SUS304 stainless steel strip.

[0022] Furthermore, the filling rate of the core powder is 18-23%.

[0023] A second aspect of this invention provides a method for preparing the above-mentioned nickel-powder-independent flux-cored welding wire for high-manganese steel, comprising the following steps:

[0024] (1) Roll the stainless steel strip into a U-shape;

[0025] (2) Weigh the powder according to the formula ratio of the core powder, mix the powder evenly to obtain the core powder;

[0026] (3) Fill the U-shaped groove of the steel strip with core powder;

[0027] (4) The U-shaped groove is rolled into an O-shaped steel pipe, and then rolled into shape, annealed, drawn and reduced in diameter, and surface mechanically cleaned in sequence to obtain flux-cored welding wire for high manganese steel.

[0028] Furthermore, the high-manganese steel described in this invention is ultra-low temperature high-manganese steel or austenitic high-manganese steel, and its chemical composition by mass percentage is: C 0.35%-0.55%, Si 0.10%-0.50%, Mn 22.5%-25.5%, Cr 3.00%-4.00%, Cu 0.30%-0.70%, B≤0.0050%, N≤0.0500%, P≤0.0200%, S≤0.0050%, with the remainder being iron and unavoidable impurities.

[0029] The flux-cored welding wire for high-manganese steel provided by this invention exhibits stable arc and molten pool during welding, with no spatter, good slag removal, and no cracks, porosity, or slag inclusions. The chemical composition of its weld, by mass percentage, includes: C 0.40%-0.55%, Mn 22%-25%, Si 0.2%-0.5%, Cr 15%-17%, Ni 5%-6%, N 0.3%-0.5%, and Nb 0.15-0.35%.

[0030] The third aspect of the present invention provides the application of the above-mentioned nickel-powder-independent flux-cored welding wire for high manganese steel in ultra-low temperature high manganese steel welding.

[0031] The flux-cored welding wire for high-manganese steel provided by this invention is suitable for arc welding, has good adaptability to welding processes, and can realize all-position welding of high-manganese ultra-low temperature steel. The comprehensive performance of the weld is excellent: tensile strength ≥850MPa, yield strength ≥400MPa, elongation ≥24%, and Akv ≥70J at -196℃. It can fully meet the mechanical property requirements of high-manganese ultra-low temperature steel and the usage requirements of the welding position.

[0032] Technical principles and beneficial effects of the present invention:

[0033] This invention involves alloy design of the weld cladding metal. By using an extremely high manganese-carbon ratio (Mn / C ≥ 45) and 0.3%~0.5% nitrogen, the weld microstructure is stabilized in extremely low temperature environments without the addition of nickel powder. This effectively solves the problem of traditional stainless steel welding wires being unable to balance strength and toughness in extremely low temperature environments, allowing the weld to still exhibit excellent impact toughness in extremely low temperature environments.

[0034] The flux-cored powder of this invention does not contain additional nickel powder, reducing reliance on imported nickel. Under this premise, the flux-cored powder is designed, and combined with the selection of stainless steel strip, welding performance and overall weld performance are simultaneously improved. A large amount of metallic manganese is added to ensure the formation of an austenitic structure in the deposited metal, and nitrogen is added as an auxiliary material for austenitization. The addition of nitrides improves the weld's processability, increases weld strength without compromising toughness. Under strong deoxidation, the recovery rate of manganese and niobium in the molten pool is significantly increased, combining with carbon to form fine niobium carbide pinning grain boundaries, preventing hot cracking.

[0035] Magnesium carbonate can decompose into magnesium oxide and carbon dioxide at high temperatures. Carbon dioxide gas provides initial protection for the weld. After adding cryolite, the cryolite can melt and vaporize rapidly at high temperatures, which can effectively reduce the surface tension of the slag and dissolve the oxide films such as alumina and silica on the surface of the molten pool. At the same time, cryolite can lower the melting point of magnesium oxide and promote its participation in the reaction.

[0036] The aluminum-magnesium alloy and silicon-calcium-barium composite agent can perform strong deoxidation, preventing alloy element burn-off and porosity formation. The displacement reaction that occurs upon contact with magnesium oxide and cryolite vapor efficiently adsorbs and removes hydrogen, oxygen, and other suspended inclusions from the molten pool. The deoxidation products of the silicon-calcium-barium composite agent, calcium oxide and barium oxide, can combine with alumina to form low-melting-point composite silicates, promoting the aggregation and flotation of inclusions. Cerium oxide reacts with inclusions at this time to generate rare earth inclusions such as cerium aluminate, which can refine the grains to some extent.

[0037] The flux-cored welding wire for high manganese steel provided by this invention is low in cost, has good adaptability to welding processes, and can simultaneously meet the requirements of high strength and high toughness at -196℃. It greatly improves the safety and stability of -196℃ class cryogenic pressure vessels and can meet the requirements of welding liquefied natural gas (LNG) equipment, aerospace fuel storage tanks and other extreme environment structures. Detailed Implementation

[0038] The present invention will be described in detail below with reference to the embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0039] The raw material powders used in the following embodiments of the present invention are as follows:

[0040] Manganese metal powder, purity ≥99.7%; aluminum-magnesium alloy powder, Al 50±0.3%, Al+Mg≥98%; niobium metal powder, purity ≥99.8%; cerium oxide, purity ≥99.9%; calcium fluoride, purity ≥97%; cryolite, purity ≥98%; magnesium carbonate, purity ≥98%; silicon-calcium-barium composite agent, Si 67%, Ca 20%, Ba 13%; manganese nitride, Mn≥90%, N≈3-5%; graphite, purity ≥98%.

[0041] In the following embodiments of the present invention, the powder of the core raw materials used were all processed by an 80-mesh sieve, and the content of each raw material with a particle size smaller than 120 mesh did not exceed 10%, and they were used after drying. Example 1

[0042] A flux-cored welding wire for high manganese steel includes a stainless steel strip and flux powder filled within the stainless steel strip. The composition of the flux powder and its mass percentage in the flux core are as follows: 40% metallic manganese powder, 1.5% aluminum-magnesium alloy powder, 1.13% metallic niobium powder, 0.75% cerium oxide, 3% calcium fluoride, 1.5% cryolite, 2.25% magnesium carbonate, 1.75% silicon-calcium-barium composite agent, 30% manganese nitride, 1.5% graphite, and the balance being iron powder.

[0043] A method for preparing flux-cored welding wire for high manganese steel includes the following steps:

[0044] (1) After surface treatment, SUS304 steel strip is rolled into a U-shaped groove;

[0045] (2) Weigh the powder according to the formula ratio of the core powder and mix the powder evenly;

[0046] (3) The flux-cored welding wire is made by filling, forming, drawing and reducing diameter, surface treatment and layer winding packaging. The flux-cored powder filling rate of the welding wire is 21%. Example 2

[0047] A flux-cored welding wire for high-manganese steel comprises a stainless steel strip and flux powder filled within the stainless steel strip. The composition of the flux powder and its mass percentage in the flux core are as follows: 35% metallic manganese powder, 1% aluminum-magnesium alloy powder, 0.5% metallic niobium powder, 0.75% cerium oxide, 3% calcium fluoride, 1.5% cryolite, 1.5% magnesium carbonate, 1% silicon-calcium-barium composite agent, 25% manganese nitride, 1% graphite, and the balance being iron powder. The welding wire is prepared using the same method as in Example 1, and the flux powder filling rate is 21%. Example 3

[0048] A flux-cored welding wire for high-manganese steel comprises a stainless steel strip and flux powder filled within the stainless steel strip. The composition of the flux powder and its mass percentage in the flux core are as follows: 45% metallic manganese powder, 2% aluminum-magnesium alloy powder, 1.75% metallic niobium powder, 1% cerium oxide, 4% calcium fluoride, 2% cryolite, 3% magnesium carbonate, 2.5% silicon-calcium-barium composite agent, 35% manganese nitride, 2% graphite, and the balance being iron powder. The welding wire is prepared using the same method as in Example 1, and the flux powder filling rate is 21%. Example 4

[0049] A flux-cored welding wire for high-manganese steel comprises a stainless steel strip and flux powder filling the stainless steel strip. The composition of the flux powder and its mass percentage in the flux core are as follows: 39.1% metallic manganese powder, 1.3% aluminum-magnesium alloy powder, 1.1% metallic niobium powder, 0.84% ​​cerium oxide, 2.6% calcium fluoride, 1.32% cryolite, 2.5% magnesium carbonate, 2.2% silicon-calcium-barium composite agent, 29.6% manganese nitride, 1.3% graphite, and the balance being iron powder. The welding wire is prepared using the same method as in Example 1, and the flux powder filling rate is 21%. Comparative Example 1

[0050] A flux-cored welding wire for high-manganese steel comprises a stainless steel strip and flux powder filled within the stainless steel strip. The composition of the flux powder and its mass percentage in the flux core are as follows: 70% metallic manganese powder, 1.5% aluminum-magnesium alloy powder, 1.13% metallic niobium powder, 0.75% cerium oxide, 3% calcium fluoride, 1.5% cryolite, 2.25% magnesium carbonate, 1.75% silicon-calcium-barium composite agent, 1.5% graphite, and the balance being iron powder. The welding wire is prepared using the same method as in Example 1, with a flux powder filling rate of 21%. Comparative Example 2

[0051] A flux-cored welding wire for high-manganese steel comprises a stainless steel strip and flux powder filled within the stainless steel strip. The composition of the flux powder and its mass percentage in the flux core are as follows: 40% metallic manganese powder, 1.5% aluminum-magnesium alloy powder, 1.13% metallic niobium powder, 3% calcium fluoride, 1.5% cryolite, 2.25% magnesium carbonate, 1.75% silicon-calcium-barium composite agent, 30% manganese nitride, 1.5% graphite, and the balance being iron powder. The welding wire is prepared using the same method as in Example 1, and the flux powder filling rate is 21%. Comparative Example 3

[0052] A flux-cored welding wire for high-manganese steel comprises a stainless steel strip and flux powder filled within the stainless steel strip. The flux composition and its mass percentage in the flux are as follows: 40% metallic manganese powder, 1.5% aluminum-magnesium alloy powder, 0.75% cerium oxide, 3% calcium fluoride, 1.5% cryolite, 2.25% magnesium carbonate, 1.75% silicon-calcium-barium composite agent, 30% manganese nitride, 1.5% graphite, and the balance being iron powder. The welding wire is prepared using the same method as in Example 1, and the flux powder filling rate is 21%. Comparative Example 4

[0053] A flux-cored welding wire for high-manganese steel comprises a stainless steel strip and flux powder filled within the stainless steel strip. The flux composition and its mass percentage in the flux are as follows: 40% metallic manganese powder, 1.5% aluminum-magnesium alloy powder, 1.13% metallic niobium powder, 0.75% cerium oxide, 3% calcium fluoride, 1.5% cryolite, 2.25% magnesium carbonate, 1.75% rutile, 30% manganese nitride, 1.5% graphite, and the balance being iron powder. The welding wire is prepared using the same method as in Example 1, and the flux powder filling rate is 21%. Comparative Example 5

[0054] A flux-cored welding wire for high-manganese steel comprises a stainless steel strip and flux powder filled within the stainless steel strip. The composition of the flux powder and its mass percentage in the flux core are as follows: 40% metallic manganese powder, 1.5% aluminum-magnesium alloy powder, 1.13% metallic niobium powder, 0.75% cerium oxide, 3% calcium fluoride, 1.5% cryolite, 2.25% magnesium carbonate, 1.75% silicon-calcium-barium composite agent, 30% manganese nitride, 3% graphite, and the balance being iron powder. The welding wire is prepared using the same method as in Example 1, and the flux powder filling rate is 21%. Comparative Example 6

[0055] A high-manganese steel flux-cored welding wire comprises a stainless steel strip and flux powder filled within the stainless steel strip. The flux composition and its mass percentage in the flux are as follows: 40% metallic manganese powder, 1.5% aluminum-magnesium alloy powder, 1.13% metallic niobium powder, 0.75% cerium oxide, 3% calcium fluoride, 1.5% cryolite, 6.75% magnesium carbonate, 1.75% silicon-calcium-barium composite agent, 30% manganese nitride, 1.5% graphite, and the balance being iron powder. The welding wire is prepared using the same method as in Example 1, and the flux powder filling rate is 21%. Comparative Example 7

[0056] A flux-cored welding wire for high-manganese steel comprises a stainless steel strip and flux powder filled within the stainless steel strip. The flux composition and its mass percentage in the flux are as follows: 40% metallic manganese powder, 2.5% aluminum-magnesium alloy powder, 1.13% metallic niobium powder, 0.75% cerium oxide, 3% calcium fluoride, 1.5% cryolite, 2.25% magnesium carbonate, 1.75% silicon-calcium-barium composite agent, 30% manganese nitride, 1.5% graphite, and the balance being iron powder. The welding wire is prepared using the same method as in Example 1, and the flux powder filling rate is 21%.

[0057] The flux-cored welding wires prepared in the above embodiments and comparative examples were used for welding high-manganese steel. The welding process is as follows:

[0058] A 30cm thick Q400GMDR steel plate was used as the welding base material, with a V-groove. Before welding, the groove and both sides were cleaned of contaminants such as oil, rust, water, and paint. The welding material used was the 1.2 specification welding wire of this invention. The welding parameters were: current 160-220A, voltage 22-26V, and an Ar / CO2 mixture was used as the shielding gas for test plate welding.

[0059] Table 1. Welding evaluation of flux-cored wires in Examples 1-4 and Comparative Examples 1-7

[0060]

[0061] Table 2 Chemical composition (wt%) of weld seams from flux-cored wires in Examples 1-4 and Comparative Examples 1-7

[0062]

[0063] Table 3 Performance analysis of flux-cored wire welded joints in Examples 1-4 and Comparative Examples 1-7

[0064]

[0065] As shown in the table, the comprehensive performance of the high manganese steel flux-cored welding wire provided by this invention in terms of deposited metal and welded joint is as follows: tensile strength ≥850MPa, yield strength ≥400MPa, elongation ≥24%, and Akv ≥70J at -196℃. It can fully meet the mechanical performance requirements of ultra-low temperature high manganese steel and the usage requirements of the welding position.

[0066] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A flux-cored welding wire for high-manganese steel that does not rely on nickel powder, characterized in that, It includes a stainless steel strip and a core powder filled within the stainless steel strip; wherein the core powder, by mass percentage, comprises: 35%-45% manganese metal powder, 1%-2% aluminum-magnesium alloy powder, 0.5%-1.75% niobium metal powder; 0.5%-1% cerium oxide, 2%-4% calcium fluoride, 1%-2% cryolite, 1.5%-3% magnesium carbonate, 1%-2.5% silicon-calcium-barium composite agent, 25%-35% manganese nitride, 1%-2% graphite, and the balance being iron powder.

2. The flux-cored welding wire for high-manganese steel that does not rely on nickel powder according to claim 1, characterized in that, The chemical composition of the silicon-calcium-barium composite agent by mass percentage is: Si 60%-70%, Ca 15%-25%, Ba 10%-20%, and unavoidable impurities.

3. The flux-cored welding wire for high-manganese steel that does not rely on nickel powder according to claim 1, characterized in that, The mass ratio of aluminum-magnesium alloy powder to cerium oxide is 2:

1.

4. The flux-cored welding wire for high-manganese steel that does not rely on nickel powder according to claim 1, characterized in that, The mass ratio of magnesium carbonate to cryolite is 1.5:

1.

5. The flux-cored welding wire for high-manganese steel that does not rely on nickel powder according to claim 1, characterized in that, The particle size of the core powder is no greater than 80 mesh, and the content of particles smaller than 120 mesh does not exceed 10%.

6. The flux-cored welding wire for high-manganese steel that does not rely on nickel powder according to claim 1, characterized in that, The chemical composition of stainless steel strip, by mass percentage, includes C 0.03%-0.10%, Si 1%-2%, Mn 0.8%-2%, Ni 8%-11%, Cr 18%-20%, with the remainder being Fe and unavoidable impurities.

7. The flux-cored welding wire for high-manganese steel that does not rely on nickel powder according to claim 6, characterized in that, The stainless steel strip is SUS304 stainless steel strip.

8. The flux-cored welding wire for high-manganese steel that does not rely on nickel powder according to claim 1, characterized in that, The filling rate of the core powder is 18%-23%.

9. The method for preparing the nickel-powder-independent flux-cored welding wire for high-manganese steel according to any one of claims 1-8, characterized in that, Includes the following steps: (1) Roll the stainless steel strip into a U-shape; (2) Weigh the powder according to the formula ratio of the core powder, mix the powder evenly to obtain the core powder; (3) Fill the U-shaped groove of the steel strip with core powder; (4) The U-shaped groove is rolled into an O-shaped steel pipe, and then rolled, annealed, drawn and reduced in diameter, and surface mechanically cleaned in sequence to obtain the flux-cored welding wire for high manganese steel.

10. An application of a flux-cored welding wire in ultra-low temperature high-manganese steel welding, characterized in that, The flux-cored welding wire is the flux-cored welding wire according to any one of claims 1-8.

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