A gas-shielded flux-cored wire for high-manganese austenitic cryogenic steel

Abstract

This invention relates to the field of gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel. The technical solution is as follows: the gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel consists of two parts: a steel strip and flux powder. The chemical composition of the steel strip is: C 0.30–0.60 wt%, Mn 26–28 wt%, P ≤ 0.002 wt%, S ≤ 0.001 wt%, with the balance being Fe and unavoidable impurities. The chemical composition of the flux powder is: TiO2 40–42 wt%, SiO2 21–22 wt%, Al2O3 2–2.5 wt%, CaO 0.7–0.8 wt%, Na2O 1.6–1.8 wt%, K2O 1.4–1.5 wt%, MnO 1.8–2.0 wt%, Ni 4–6 wt%, FeCr85C11 5–6 wt%, with the balance being iron powder. This invention features simple steel strip composition, low powder cost, and low powder filling rate. The gas-shielded flux-cored welding wire prepared for high-manganese austenitic low-temperature steel can be matched with high-manganese austenitic low-temperature steel.

Description

Technical Field

[0001] This invention belongs to the field of gas-shielded flux-cored welding wire technology. Specifically, it relates to a gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel. Background Technology

[0002] In the construction of cryogenic storage tanks, such as liquefied natural gas (LNG) tanks, using high-manganese austenitic cryogenic steel, flux-cored welding wire is a commonly used welding material. Flux-cored welding wire consists of two parts: a steel strip and flux powder. The steel strip primarily serves to coat the flux powder and also acts as a transition alloying element. Furthermore, the filling rate and composition of the flux powder are controlled and influenced by the chemical composition and specifications of the steel strip. In other words, the steel strip largely determines the design and production of the flux-cored welding wire.

[0003] Regarding the production of steel strips and flux-cored welding wires for high-manganese austenitic low-temperature steel, the currently disclosed technologies include:

[0004] The "Seamless Submerged Arc Flux-Cored Welding Wire for Welding High-Manganese Steel LNG Storage Tanks" (CN 201911049624.1) uses low-carbon steel strip for the outer sheath. The mass percentage of the elements contained is: C≤0.06%, Si≤0.02%, Mn0.1~0.4%, S≤0.01%, P≤0.015%, Fe≥98%. The filling rate of the high-manganese austenitic steel flux-cored welding wire of this technology needs to be as high as 30~40% to meet the requirement that the total amount of alloying elements (Mn+Cr+Mo+C) in the deposited metal reaches 33~35%.

[0005] The patented technology, "Ultra-low Temperature High Manganese Steel Flux-cored Welding Wire for All-Position Welding and Its Application" (CN202110816857.0), uses low-carbon steel strip and transitions alloying elements Mn, Cr, and Ni through the flux core. Therefore, the flux core mass is 35-45% of the total mass of the flux-cored welding wire. This means that the filling rate needs to reach 35-45% during the production of the flux-cored welding wire. However, the current limit for the filling rate of flux-cored welding wire production lines is only 30-33%, which is insufficient to meet the production requirements of the above-mentioned technology. Furthermore, the flux powder in this technology contains a large number of alloying elements, resulting in a complex composition.

[0006] Regarding the steel strip of flux-cored welding wire for high-manganese austenitic low-temperature steel, the currently disclosed technologies include: Patent technology "A Flux Combination for Metal Powder Cored Submerged Arc Welding Wire for 25Mn Austenitic Steel" (202010599845.2), which only discloses the composition and ratio of the flux powder, but does not provide the composition system of the steel strip. Patent technology "A High-Efficiency Submerged Arc Welding Metal Powder Cored Flux-Cored Welding Wire Suitable for Ultra-Low Temperature High-Manganese Steel" (201811602479.0), whose steel strip chemical composition is: C 0.20–0.23 wt%, Si 0.03–0.05 wt%, Mn 6–8 wt%, P ≤ 0.002 wt%, S ≤ 0.001 wt%, with the balance being Fe and unavoidable impurities. Although this technology increases the manganese content in the steel strip, when the alloy composition is 6-8 wt% Mn and 0.20-0.23 wt% C, the room temperature microstructure of the steel strip blank is a hard and brittle martensitic structure, which is prone to wire breakage during the drawing process of flux-cored welding wire, making it difficult to produce flux-cored welding wire for high-manganese austenitic low-temperature steel, especially for small-diameter gas-shielded flux-cored welding wire. Summary of the Invention

[0007] The present invention aims to overcome the shortcomings of the prior art and provides a gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel with simple steel strip composition, low flux cost and low flux filling rate. The gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel can be matched with high-manganese austenitic low-temperature steel.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: the gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel consists of two parts: steel strip and flux powder.

[0009] The chemical composition of the steel strip is: C 0.30-0.60 wt%, Mn 26-28 wt%, P ≤0.002 wt%, S ≤0.001 wt%, with the balance being Fe and unavoidable impurities.

[0010] The chemical composition of the powder is as follows: TiO2 40-42 wt%, SiO2 21-22 wt%, Al2O3 2-2.5 wt%, CaO 0.7-0.8 wt%, Na2O 1.6-1.8 wt%, K2O 1.4-1.5 wt%, MnO 1.8-2.0 wt%, Ni 4-6 wt%, FeCr85C11 5-6 wt%, with the balance being iron powder.

[0011] The method for preparing the gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel is as follows: steel strip is rolled into a U-shaped tube, flux powder is added into the U-shaped tube, and then the wire is joined, drawn and reduced in diameter, wound, surface treated and layered to obtain the gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel.

[0012] The purity of the TiO2 is ≥99%; the particle size of the TiO2 is ≤0.3mm.

[0013] The purity of the SiO2 is ≥99%; the particle size of the SiO2 is ≤0.3mm.

[0014] The purity of the Al2O3 is ≥99%; the particle size of the Al2O3 is ≤0.3mm.

[0015] The purity of the CaO is ≥99%; the particle size of the CaO is ≤0.3mm.

[0016] The purity of the Na2O is ≥99%; the particle size of the Na2O is ≤0.3mm.

[0017] The purity of the K2O is ≥99%; the particle size of the K2O is ≤0.3mm.

[0018] The purity of the MnO is ≥99%; the particle size of the MnO is ≤0.3mm.

[0019] The purity of Ni is ≥99%; the particle size of Ni is ≤0.3mm.

[0020] The chemical composition of FeCr85C11 is: 84-86 wt% Cr, 10-12 wt% C, with the balance being iron and unavoidable impurities; the particle size of FeCr85C11 is ≤0.30 mm.

[0021] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0022] 1. This invention employs a steel strip as the primary alloying element, C, and Mn, for transition. Firstly, this ensures that the C and Mn content in the weld metal meets technical requirements. Secondly, compared to using flux powder, the steel strip method results in a higher and more stable alloy element content in the weld metal. Thirdly, the steel strip method reduces the alloy element content in the flux powder, effectively lowering the flux powder filling rate and meeting the technical requirements of existing flux-cored wire production equipment. Adding 0.30–0.60 wt% C and 26–28 wt% Mn to the steel strip ensures that the weld metal contains 0.25–0.55 wt% C and 25–26 wt% Mn.

[0023] The steel strip in this invention has extremely low impurity element content, P≤0.002wt%, S≤0.001wt%, which is the raw material for ultra-pure flux-cored welding wire. This ensures that the gas-shielded flux-cored welding wire prepared for high-manganese austenitic low-temperature steel can guarantee excellent weldability, excellent low-temperature performance and good mechanical property stability during use.

[0024] 2. In this invention, the amount of TiO2 added to the flux powder is 40-42 wt%. During the welding process, a thin protective slag layer is formed, reducing the porosity sensitivity of the weld metal and ensuring its quality. The use of TiO2 not only acts as a slag-forming agent but also stabilizes the arc, effectively improving the weld metal's formability. Furthermore, TiO2 can work synergistically with Na2O and K2O to adjust the melting point and viscosity of the slag, reducing its solidification temperature and achieving "short slag," thus adapting to all-position welding.

[0025] The present invention utilizes SiO2 and Al2O3 in the powder to form slag during the welding process, which provides good protection and ensures that the weld metal has excellent welding quality; at the same time, it also improves the weld formation.

[0026] The present invention adds 4-6 wt% nickel powder to the powder to ensure that 3-4% Ni element is obtained in the deposited metal; and adds 5-6 wt% high carbon ferrochrome to ensure that 4-5% Cr element is obtained in the deposited metal. That is, adding nickel powder and high carbon ferrochrome can transfer the alloying elements Ni and Cr into the deposited metal.

[0027] 3. The gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel prepared by this invention stabilizes the alloy element content of the deposited metal, reduces the flux filling rate to 27-30%, and can produce fine-diameter flux-cored welding wires with a diameter of 1.0-1.2 mm. Using the gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel prepared by this invention, 100% CO2 shielded welding is achieved, enabling fully automated welding with high welding efficiency.

[0028] 4. This invention can form a thin protective slag during the welding process. When using 100% CO2 gas for protection, under the combined gas-slag protection, the weld metal formed has good shape and low porosity sensitivity. It can be used for all-position welding, can achieve fully automatic welding, and has high welding efficiency. The weld metal formed has the characteristics of ultra-low temperature high toughness, and its strength matches that of high-manganese austenitic low-temperature steel. The welded joint has high strength and excellent ultra-low temperature toughness, which can meet the technical requirements for the strength and ultra-low temperature toughness of the welded high-manganese austenitic low-temperature steel with a working temperature of -196℃.

[0029] 5. The gas-shielded flux-cored welding wire prepared by this invention for high-manganese austenitic low-temperature steel is used for gas-shielded welding of high-manganese austenitic low-temperature steel. The deposited metal forms a fully austenitic structure, which not only ensures excellent ultra-low temperature toughness, with an impact energy Akv of 65-70J at -196℃, but also ensures sufficient strength: yield strength of 420-430MPa, tensile strength of 670-710MPa, and elongation A of 42-45%, thus achieving the strength and ultra-low temperature toughness requirements of high-manganese austenitic low-temperature steel at a working temperature of -196℃.

[0030] Therefore, the present invention has the characteristics of simple steel strip composition, low powder cost and low powder filling rate, and the gas-shielded flux-cored welding wire prepared for high manganese austenitic low temperature steel is compatible with high manganese austenitic low temperature steel. Detailed Implementation

[0031] The present invention will be further described below with reference to specific embodiments, but this is not intended to limit the scope of protection of the invention.

[0032] To avoid repetition, the technical parameters of the relevant processes and materials involved in this specific embodiment are described in a unified manner as follows, and will not be repeated in the embodiments:

[0033] The gas-shielded flux-cored welding wire used for high-manganese austenitic low-temperature steel consists of two parts: steel strip and flux powder.

[0034] The method for preparing the gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel is as follows: steel strip is rolled into a U-shaped tube, flux powder is added into the U-shaped tube, and then the wire is joined, drawn and reduced in diameter, wound, surface treated and layered to obtain the gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel.

[0035] The purity of the TiO2 is ≥99%; the particle size of the TiO2 is ≤0.3mm.

[0036] The purity of the SiO2 is ≥99%; the particle size of the SiO2 is ≤0.3mm.

[0037] The purity of the Al2O3 is ≥99%; the particle size of the Al2O3 is ≤0.3mm.

[0038] The purity of the CaO is ≥99%; the particle size of the CaO is ≤0.3mm.

[0039] The purity of the Na2O is ≥99%; the particle size of the Na2O is ≤0.3mm.

[0040] The purity of the K2O is ≥99%; the particle size of the K2O is ≤0.3mm.

[0041] The purity of the MnO is ≥99%; the particle size of the MnO is ≤0.3mm.

[0042] The purity of Ni is ≥99%; the particle size of Ni is ≤0.3mm.

[0043] The particle size of the FeCr85C11 is ≤0.30mm.

[0044] Example 1

[0045] A gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel. This gas-shielded flux-cored welding wire consists of two parts: a steel strip and flux powder.

[0046] The chemical composition of the steel strip is: C 0.40-0.50 wt%, Mn 26.8-27.2 wt%, P ≤0.002 wt%, S ≤0.001 wt%, with the balance being Fe and unavoidable impurities.

[0047] The chemical composition of the powder is as follows: TiO2 40.5-41.2 wt%, SiO2 21.3-21.6 wt%, Al2O3 2.4-2.5 wt%, CaO 0.7-0.72 wt%, Na2O 1.75-1.8 wt%, K2O 1.4-1.42 wt%, MnO 1.94-2.0 wt%, Ni 4-4.8 wt%, FeCr85C11 5.6-6 wt%, with the balance being iron powder.

[0048] The chemical composition of FeCr85C11 is: Cr 84-86 wt%, C 10-12 wt%, with the balance being iron and unavoidable impurities.

[0049] The diameter of the gas-shielded flux-cored welding wire prepared in this embodiment for high-manganese austenitic low-temperature steel is 1.0 mm.

[0050] The chemical composition of the high-manganese austenitic low-temperature steel described in this embodiment is as follows: C 0.40–0.450 wt%, Si 0.10–0.15 wt%, Mn 20–24 wt%, N 0.06–0.08 wt%, P ≤0.004 wt%, S ≤0.001 wt%, with the balance being Fe and unavoidable impurities. The mechanical properties of the high-manganese austenitic low-temperature steel are: tensile strength ≥400 MPa, yield strength ≥560 MPa, elongation A ≥40%; impact energy Akv ≥54 J at -196℃. The thickness of the high-manganese austenitic low-temperature steel is 16 mm, the bevel type is X-type, and the bevel angle on one side is 30°; the protective gas used is 100 vol% CO2, and the protective gas flow rate is 15–20 L / min.

[0051] The gas-shielded flux-cored welding wire prepared in this embodiment for high-manganese austenitic low-temperature steel was used to test and analyze the microstructure and mechanical properties of the weld metal after gas-shielded welding: the weld metal is a fully austenitic structure with no solidification cracks or reheat cracks; the yield strength of the weld metal is 420-425 MPa, the tensile strength is 670-691 MPa, the elongation A is 44-45%, and the average impact energy Akv at -196℃ is 67-70 J.

[0052] Example 2

[0053] A gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel. This gas-shielded flux-cored welding wire consists of two parts: a steel strip and flux powder.

[0054] The chemical composition of the steel strip is: C 0.30-0.40 wt%, Mn 27.2-28 wt%, P ≤0.002 wt%, S ≤0.001 wt%, with the balance being Fe and unavoidable impurities.

[0055] The chemical composition of the powder is as follows: TiO2 40-40.5 wt%, SiO2 21-21.3 wt%, Al2O3 2-2.2 wt%, CaO 0.72-0.75 wt%, Na2O 1.68-1.75 wt%, K2O 1.42-1.46 wt%, MnO 1.8-1.88 wt%, Ni 4.8-5.4 wt%, FeCr85C11 5.3-5.6 wt%, with the balance being iron powder.

[0056] The chemical composition of FeCr85C11 is: Cr 84-86 wt%, C 10-12 wt%, with the balance being iron and unavoidable impurities.

[0057] The diameter of the gas-shielded flux-cored welding wire prepared in this embodiment for high-manganese austenitic low-temperature steel is 1.2 mm.

[0058] The chemical composition of the high-manganese austenitic low-temperature steel described in this embodiment is: C 0.45–0.48 wt%, Si 0.15–0.18 wt%, Mn 24–26 wt%, N 0.03–0.06 wt%, P ≤0.005 wt%, S ≤0.002 wt%, with the balance being Fe and unavoidable impurities. The mechanical properties of the high-manganese austenitic low-temperature steel are: tensile strength ≥400 MPa, yield strength ≥560 MPa, elongation A ≥40%; impact energy A at -196℃. kv ≥54J. The thickness of the high-manganese austenitic low-temperature steel is 16mm, the bevel type is X-shaped, and the bevel angle on one side is 30°; the protective gas used is 100 vol% CO2, and the protective gas flow rate is 15-20 L / min.

[0059] The gas-shielded flux-cored welding wire prepared in this embodiment for high-manganese austenitic low-temperature steel was used to test and analyze the microstructure and mechanical properties of the weld metal after gas-shielded welding. The weld metal was found to be a fully austenitic structure, with no solidification cracks or reheat cracks. The yield strength of the weld metal was 422–428 MPa, the tensile strength was 681–705 MPa, the elongation A was 43–44%, and the average impact energy A at -196℃ was [missing value]. kv =65~69J.

[0060] Example 3

[0061] A gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel. This gas-shielded flux-cored welding wire consists of two parts: a steel strip and flux powder.

[0062] The chemical composition of the steel strip is: C 0.50-0.60 wt%, Mn 26-26.8 wt%, P ≤0.001 wt%, S ≤0.001 wt%, with the balance being Fe and unavoidable impurities.

[0063] The chemical composition of the powder is as follows: TiO2 41.2-42 wt%, SiO2 21.6-22 wt%, Al2O3 2.2-2.4 wt%, CaO 0.75-0.8 wt%, Na2O 1.6-1.68 wt%, K2O 1.46-1.5 wt%, MnO 1.88-1.94 wt%, Ni 5.4-6 wt%, FeCr85C11 5-5.3 wt%, with the balance being iron powder.

[0064] The chemical composition of FeCr85C11 is: Cr 84-86 wt%, C 10-12 wt%, with the balance being iron and unavoidable impurities.

[0065] The diameter of the gas-shielded flux-cored welding wire prepared in this embodiment for high-manganese austenitic low-temperature steel is 1.2 mm.

[0066] The chemical composition of the high-manganese austenitic low-temperature steel described in this embodiment is: C 0.48–0.50 wt%, Si 0.18–0.20 wt%, Mn 26–28 wt%, N 0.01–0.03 wt%, P ≤0.003 wt%, S ≤0.001 wt%, with the balance being Fe and unavoidable impurities. The mechanical properties of the high-manganese austenitic low-temperature steel are: tensile strength ≥400 MPa, yield strength ≥560 MPa, elongation A ≥40%; impact energy A at -196℃. kv ≥54J. The thickness of the high-manganese austenitic low-temperature steel is 16mm, the bevel type is X-shaped, and the bevel angle on one side is 30°; the protective gas used is 100 vol% CO2, and the protective gas flow rate is 15-20 L / min.

[0067] The gas-shielded flux-cored welding wire prepared in this embodiment for high-manganese austenitic low-temperature steel was used to analyze the microstructure and mechanical properties of the weld metal after gas-shielded welding. The weld metal was found to be a fully austenitic structure with no solidification cracks or reheat cracks. The yield strength of the weld metal was 725–730 MPa, the tensile strength was 690–710 MPa, the elongation A was 42–44%, and the average impact energy A at -196℃ was [missing value]. kv =66~69J.

[0068] This specific implementation method has the following advantages compared with the prior art:

[0069] 1. This specific implementation method uses a steel strip as the main alloying elements (C and Mn) for transition. Firstly, this ensures that the C and Mn content in the weld metal meets technical requirements. Secondly, compared to using flux powder, the alloying element content in the weld metal is higher and more stable when using a steel strip for transition. Thirdly, the transition of C and Mn elements into the weld metal via a steel strip reduces the alloying element composition in the flux powder, effectively lowering the flux powder filling rate and meeting the technical requirements of existing flux-cored wire production equipment. Adding 0.30–0.60 wt% C and 26–28 wt% Mn to the steel strip ensures that the weld metal contains 0.25–0.55 wt% C and 25–26 wt% Mn.

[0070] In this specific embodiment, the impurity element content of the steel strip is extremely low, with P≤0.002wt% and S≤0.001wt%, making it an ultra-pure raw material for flux-cored welding wire. This ensures that the gas-shielded flux-cored welding wire prepared for high-manganese austenitic low-temperature steel can guarantee excellent weldability, superior low-temperature performance, and good mechanical property stability during use.

[0071] 2. In this specific embodiment, the amount of TiO2 added to the flux powder is 40-42 wt%. During welding, a thin protective slag layer is formed, reducing the porosity sensitivity of the weld metal and ensuring its quality. The use of TiO2 not only acts as a slag-forming agent but also stabilizes the arc, effectively improving the weld metal's formability. Furthermore, TiO2 can work synergistically with Na2O and K2O to adjust the melting point and viscosity of the slag, reducing its solidification temperature and achieving "short slag," thus adapting to all-position welding.

[0072] In this specific embodiment, the combined action of SiO2 and Al2O3 in the flux powder forms slag during welding, providing excellent protection and ensuring superior weld quality. It also improves weld bead formation.

[0073] In this specific embodiment, 4-6 wt% nickel powder is added to the powder to ensure that 3-4% Ni element is obtained in the deposited metal; 5-6 wt% high carbon ferrochrome is added to ensure that 4-5% Cr element is obtained in the deposited metal. That is, adding nickel powder and high carbon ferrochrome can transfer the alloying elements Ni and Cr into the deposited metal.

[0074] 3. The gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel prepared in this specific embodiment ensures stable alloy element content in the deposited metal, reduces the flux powder filling rate to 27-30%, and enables the preparation of fine-diameter flux-cored welding wires with a diameter of 1.0-1.2 mm. Using the gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel prepared in this specific embodiment achieves 100% CO2 shielded welding, enabling fully automated welding with high welding efficiency.

[0075] 4. In this specific embodiment, a thin protective slag layer can be formed during the welding process. When using 100% CO2 gas for protection, under the combined gas-slag protection, the weld metal formed has good formation and low porosity sensitivity. It can be used for all-position welding, can achieve fully automatic welding, and has high welding efficiency. The weld metal formed has the characteristics of ultra-low temperature high toughness, and its strength matches that of high-manganese austenitic low-temperature steel. The welded joint has high strength and excellent ultra-low temperature toughness, which can meet the technical requirements for the strength and ultra-low temperature toughness of the welded high-manganese austenitic low-temperature steel suitable for working temperature of -196℃.

[0076] 5. The gas-shielded flux-cored welding wire prepared in this specific embodiment for high-manganese austenitic low-temperature steel is used for gas-shielded welding of high-manganese austenitic low-temperature steel. The deposited metal forms a fully austenitic structure, which not only ensures excellent ultra-low temperature toughness, with an impact energy Akv of 65-70J at -196℃, but also ensures sufficient strength: yield strength of 420-430MPa, tensile strength of 670-710MPa, and elongation A of 42-45%, thus achieving the strength and ultra-low temperature toughness requirements of high-manganese austenitic low-temperature steel at a working temperature of -196℃.

[0077] Therefore, this specific embodiment has the characteristics of simple steel strip composition, low powder cost and low powder filling rate, and the gas-shielded flux-cored welding wire prepared for high-manganese austenitic low-temperature steel is compatible with high-manganese austenitic low-temperature steel.

Claims

1. A gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel, characterized in that... The gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel consists of two parts: steel strip and flux powder. The chemical composition of the steel strip is: C 0.30-0.60 wt%, Mn 26-28 wt%, P ≤0.002 wt%, S ≤0.001 wt%, with the balance being Fe and unavoidable impurities; The chemical composition of the powder is as follows: TiO2 40-42 wt%, SiO2 21-22 wt%, Al2O3 2-2.5 wt%, CaO 0.7-0.8 wt%, Na2O 1.6-1.8 wt%, K2O 1.4-1.5 wt%, MnO 1.8-2.0 wt%, Ni 4-6 wt%, FeCr85C11 5-6 wt%, with the balance being iron powder; The method for preparing the gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel is as follows: steel strip is rolled into a U-shaped tube, flux powder is added into the U-shaped tube, and then the wire is joined, drawn and reduced in diameter, wound, surface treated and layered to obtain the gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel.

2. The gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel according to claim 1, characterized in that... The purity of the TiO2 is ≥99%; The particle size of TiO2 is ≤0.3mm.

3. The gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel according to claim 1, characterized in that... The purity of the SiO2 is ≥99%; The particle size of SiO2 is ≤0.3mm.

4. The gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel according to claim 1, characterized in that... The purity of the Al2O3 is ≥99%; the particle size of the Al2O3 is ≤0.3mm.

5. The gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel according to claim 1, characterized in that... The purity of the CaO is ≥99%; the particle size of the CaO is ≤0.3mm.

6. The gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel according to claim 1, characterized in that... The purity of the Na2O is ≥99%; the particle size of the Na2O is ≤0.3mm.

7. The gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel according to claim 1, characterized in that... The purity of the K2O is ≥99%; the particle size of the K2O is ≤0.3mm.

8. The gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel according to claim 1, characterized in that... The purity of the MnO is ≥99%; the particle size of the MnO is ≤0.3mm.

9. The gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel according to claim 1, characterized in that... The purity of Ni is ≥99%; the particle size of Ni is ≤0.3mm.

10. The gas-shielded flux-cored welding wire for high-manganese austenitic low-temperature steel according to claim 1, characterized in that... The chemical composition of FeCr85C11 is: 84-86 wt% Cr, 10-12 wt% C, with the balance being iron and unavoidable impurities; the particle size of FeCr85C11 is ≤0.30 mm.