Seamless submerged arc welding wire, welding flux and preparation method of seamless submerged arc welding wire

Abstract

The invention provides a seamless submerged arc welding wire, a welding flux and a preparation method of the seamless submerged arc welding wire. The seamless submerged arc welding wire comprises a steel belt and a flux core filled in the steel belt, a copper plating layer is arranged on the surface of the seamless submerged arc welding wire, and the flux core comprises, by weight, 75-82 parts of iron powder, 1.8-2.5 parts of chromium metal, 5-7 parts of nickel powder, 2.5-4 parts of ferromolybdenum, 4-7 parts of manganese metal, 0.3-0.6 part of graphite, 0.5-1 part of rare earth fluoride, 0.5-1 part of Teflon and 0.5-1.5 parts of marble. The flux comprises the following components in parts by weight: 10 to 13 parts of bauxite, 38 to 43 parts of manganese ore, 18 to 21 parts of calcium aluminate, 8 to 11 parts of fluorite and 12 to 15 parts of magnesia. The welding wire and the welding flux are used in a combined mode, and the welding wire has the advantages of being good in welding manufacturability, excellent in mechanical property, ultralow in diffusible hydrogen, low in deposited metal oxygen content and good in horizontal position welding technological property.

Description

Technical Field

[0001] This invention relates to the field of welding materials technology, and in particular to a seamless submerged arc welding wire, flux, and preparation method thereof. Background Technology

[0002] With the increasing demands for structural performance in fields such as construction, engineering machinery, and marine engineering, the application of high-strength and high-toughness steel is becoming more widespread. However, the welding materials used to match these requirements face numerous severe challenges. Currently, solid submerged arc welding wires on the market have fixed compositions, and their welding performance largely depends on the flux. As a key material, the flux is prone to moisture absorption. Once the flux absorbs moisture, it significantly increases the diffusible hydrogen and oxygen content in the weld, affecting weld performance and weakening the reliability and stability of the welded structure. Furthermore, most metal-cored submerged arc welding wires on the market use a welded, non-copper-plated design, making moisture absorption difficult to avoid. Moisture absorption leads to a significant increase in the diffusible hydrogen content, resulting in severe hydrogen-induced cracking, greatly affecting weld quality, and hindering long-term storage, increasing usage costs and management difficulties. More critically, the alloy systems used in existing welding materials are not specifically designed for the high requirements of certain industries for low-alloy steel. They have significant deficiencies in diffusible hydrogen control, low-temperature impact stability, and crack resistance, making it difficult to meet the requirements for low-alloy steel with tensile strengths reaching or exceeding 620 MPa. Summary of the Invention

[0003] This invention provides a seamless submerged arc welding wire, flux, and preparation method thereof to meet the application requirements of low alloy steel welding.

[0004] This invention provides a seamless submerged arc welding wire, comprising a steel strip and a flux core filled within the steel strip. The surface of the seamless submerged arc welding wire is coated with a copper layer. The flux core comprises the following components in parts by weight: 75-82 parts iron powder, 1.8-2.5 parts metallic chromium, 5-7 parts nickel powder, 2.5-4 parts ferromolybdenum, 4-7 parts metallic manganese, 0.3-0.6 parts graphite, 0.5-1 parts rare earth fluoride, 0.5-1 parts Teflon, and 0.5-1.5 parts marble.

[0005] In one embodiment of the present invention, the steel strip is a low-carbon steel strip, and the steel strip comprises the following components and the mass percentage of each component are as follows: C≤0.05%, Mn≤0.35%, Si≤0.1%, S≤0.03%, P≤0.03%, with the remainder being Fe and unavoidable impurities.

[0006] In one embodiment of the present invention, the diameter of the seamless submerged arc welding wire is 2.0 to 5.0 mm, and the thickness of the copper plating layer is 0.3 to 0.5 μm.

[0007] In one embodiment of the present invention, the filling rate of the core is 32-40%.

[0008] This invention also provides a method for preparing seamless submerged arc welding wire, comprising the following steps:

[0009] Weigh and mix the core powder according to the specified ratio to obtain the core.

[0010] The steel strip is rolled into a U-shaped groove, and the core is filled into the U-shaped groove. The gap of the steel strip is then closed and welded.

[0011] The steel strip filled with the flux core is drawn to reduce its diameter, then copper-plated on its surface and drawn and polished to obtain a seamless submerged arc welding wire.

[0012] The present invention also provides a flux adapted to the above-mentioned seamless submerged arc welding wire, the flux comprising the following components in parts by weight: 10-13 parts bauxite, 38-43 parts manganese ore, 18-21 parts calcium aluminate, 8-11 parts fluorite, and 12-15 parts magnesia.

[0013] The present invention also provides a method for preparing a flux, comprising the following steps:

[0014] The components of the flux are mixed in proportion and stirred evenly to obtain flux powder;

[0015] The flux powder is placed in a heating furnace and heated to melt it into liquid flux.

[0016] The flux liquid is poured into water and cooled to obtain glassy particles. The glassy particles are then crushed, sieved, and dried to obtain the flux.

[0017] In one embodiment of the present invention, when the flux powder is heated in a heating furnace, the temperature of the heating furnace is 1300-1500°C.

[0018] In one embodiment of the present invention, the particle size of the flux is 10 to 60 mesh.

[0019] In one embodiment of the present invention, when the glassy particles are crushed, sieved and dried, the drying temperature is 350-400°C.

[0020] The beneficial effects of this invention are as follows: This invention provides a seamless submerged arc welding wire and flux. The seamless submerged arc welding wire of this invention has the advantages of being able to undergo surface copper plating, having good rust resistance, and good electrical conductivity. Furthermore, the seamless nature of the wire reduces the risk of moisture absorption, allowing for larger coil weights, reducing the frequency of wire replacement, improving work efficiency, and reducing joints in the weld. The flux of this invention features low moisture absorption, good compositional uniformity, and stable welding processability. The combination of the welding wire and flux of this invention results in good welding processability, excellent mechanical properties, ultra-low diffusible hydrogen, low oxygen content in the deposited metal, and good horizontal welding process performance. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0022] In the attached diagram:

[0023] Figure 1 A flowchart illustrating the preparation process of a seamless submerged arc welding wire according to an embodiment of the present invention;

[0024] Figure 2 This is a flowchart illustrating the preparation process of flux according to an embodiment of the present invention. Detailed Implementation

[0025] 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. 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. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0026] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0027] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0028] This invention provides a seamless submerged arc welding wire, which includes a steel strip and a flux core filled within the steel strip. The surface of the seamless submerged arc welding wire is coated with a copper layer. The flux core comprises the following components in parts by weight: 75-82 parts iron powder, 1.8-2.5 parts metallic chromium, 5-7 parts nickel powder, 2.5-4 parts ferromolybdenum, 4-7 parts metallic manganese, 0.3-0.6 parts graphite, 0.5-1 parts rare earth fluoride, 0.5-1 parts Teflon, and 0.5-1.5 parts marble.

[0029] In this invention, the functions of each component in the core are as follows:

[0030] Iron powder: It regulates the chemical composition of the weld metal deposited in the welding wire and stabilizes the wire's performance. Iron powder can also improve the arc state and regulate the fluidity of molten iron.

[0031] Metallic chromium: Transmits chromium into the weld metal, increasing its strength. However, excessive addition can lead to a decrease in weld toughness.

[0032] Nickel powder: mainly used for alloying, adjusting the nickel content of the deposited metal to give the weld better crack resistance and toughness.

[0033] Ferromolybdenum: Introduces molybdenum into the weld metal, increasing its strength. Excessive addition can lead to decreased weld toughness.

[0034] Metallic manganese: mainly used as a deoxidizer, alloying agent and desulfurizer, to transfer Mn element to the weld and improve the weld strength.

[0035] Graphite: Its main functions are deoxidation and the introduction of carbon into the weld. Carbon helps reduce the formation of hot cracks; the increase in carbon makes the weld metal shrink more evenly during cooling, reducing stress concentration and thus reducing shrinkage stress. In addition, graphite can increase the lubricity of the flux powder, which can improve the coating performance of the welding wire and the smoothness of the wire surface.

[0036] Rare earth fluorides: alter the microstructure of weld metal to improve mechanical properties.

[0037] Teflon (polytetrafluoroethylene): Increases the flowability and uniformity of pharmaceutical powder. Teflon also removes hydrogen during high-temperature decomposition.

[0038] Marble: Its main component is CaCO3, which has gas-generating and slag-forming effects. During welding, it decomposes to produce CO2 and CaO-based alkaline oxides. CO2 protects the molten pool from air intrusion. CaO increases the basicity of the slag, refines the molten droplets, and has the effect of removing sulfur and phosphorus, improving the weld metal's resistance to cracking. Adding too much will increase spatter, while adding too little will result in porosity defects in the product. During welding, marble decomposes into CO2 gas, reducing the hydrogen partial pressure in the weld pool and minimizing the transition of hydrogen phases in the weld.

[0039] In one embodiment of the present invention, the steel strip is a low-carbon steel strip, and the steel strip comprises the following components and the mass percentage of each component are as follows: C≤0.05%, Mn≤0.35%, Si≤0.1%, S≤0.03%, P≤0.03%, and the remainder is Fe and unavoidable impurities.

[0040] In one embodiment of the present invention, the diameter of the seamless submerged arc welding wire is 2.0 to 5.0 mm, and the thickness of the copper plating layer is 0.3 to 0.5 μm.

[0041] In one embodiment of the present invention, the filling rate of the flux core is 32-40%, that is, the weight of the flux core accounts for 32-40% of the total weight of the seamless submerged arc welding wire.

[0042] Please see Figure 1 , Figure 1 A method for preparing seamless submerged arc welding wire according to an embodiment of the present invention includes the following steps:

[0043] S11. Weigh and mix the core powder according to the formula to obtain the core;

[0044] S12. Roll the steel strip into a U-shaped groove, fill the U-shaped groove with the flux core, and close and weld the gap of the steel strip.

[0045] S13. The steel strip filled with flux is drawn to reduce its diameter, and after copper plating on its surface, it is drawn and polished to obtain a seamless submerged arc welding wire.

[0046] In step S11, the core comprises the following components in parts by weight: 75-82 parts iron powder, 1.8-2.5 parts metallic chromium, 5-7 parts nickel powder, 2.5-4 parts ferromolybdenum, 4-7 parts metallic manganese, 0.3-0.6 parts graphite, 0.5-1 parts rare earth fluoride, 0.5-1 parts Teflon, and 0.5-1.5 parts marble.

[0047] In step S12, the steel strip is a low-carbon steel strip, and by mass percentage, the steel strip comprises the following components and their respective mass percentages: C≤0.05%, Mn≤0.35%, Si≤0.1%, S≤0.03%, P≤0.03%, with the remainder being Fe and unavoidable impurities. Exemplarily, laser welding is used to join the gaps in the steel strip.

[0048] In step S13, for example, the steel strip filled with flux is first drawn to a diameter of 2.10–5.10 mm, and then electrochemical copper plating and diameter reduction polishing are performed on the outside of the steel strip to obtain a seamless submerged arc welding wire with a diameter of 2.0–5.0 mm. For example, the thickness of the copper plating layer is 0.3–0.5 μm.

[0049] The seamless submerged arc welding wire of this application allows for customization of the alloy composition by adjusting the flux formula. It allows for the addition of easily decomposed and oxidized components that cannot be added to the flux. The wire drawing process is simple, resulting in high welding efficiency. Furthermore, it offers greater controllability of the composition compared to solid welding wire. In contrast to ordinary flux-cored submerged arc welding wire, the wire of this invention employs a seamless manufacturing process, and its surface can be copper-plated to improve rust and moisture resistance, allowing for larger coil weights and increased work efficiency. Copper plating also improves electrical conductivity, increases welding arc stability, and reduces wear on the contact tip.

[0050] The present invention also provides a flux compatible with the above-mentioned seamless submerged arc welding wire, the flux comprising the following components in parts by weight: 10-13 parts bauxite, 38-43 parts manganese ore, 18-21 parts calcium aluminate, 8-11 parts fluorite, and 12-15 parts magnesia.

[0051] In this invention, the functions of each component in the flux are as follows:

[0052] Bauxite: Its main components are Al2O3 and SiO2. SiO2 increases the viscosity and covering power of the slag, protecting the molten pool from oxidation. Al2O3 improves the high-temperature stability of the slag and reduces fluoride volatilization; however, excessive amounts will increase the viscosity of the slag and affect slag removal.

[0053] Manganese ore: Its main components are MnO and SiO2. MnO can act as a deoxidizer and can also react with SiO2 to form MnO·SiO2 slag, which is beneficial for slag removal from welds.

[0054] Calcium aluminate: Its main components are Al2O3 and CaO. CaO can regulate alkalinity and improve desulfurization and dephosphorization capabilities. However, excessive amounts can lead to overly thin slag, which is detrimental to weld formation.

[0055] Fluorite: Its main component is CaF2. It can adjust the viscosity of slag, improve weld fluidity, and the fluorite element combines with the harmful element hydrogen, reducing the hydrogen content in the weld and purifying the weld. Too much fluorite will lead to poor weld formation, while too little fluorite will easily cause porosity defects.

[0056] Magnesia: Its main component is MgO, which can replace some CaO, adjust alkalinity, reduce slag erosion, and increase slag viscosity at high temperatures, making it suitable for high-current welding. For example, calcined magnesia is selected. After high-temperature calcination, the magnesium oxide crystal structure of calcined magnesia is highly compacted, with extremely low chemical activity. It hardly absorbs moisture from the air, significantly reducing the risk of increased porosity and spatter during welding due to moisture absorption by the welding wire, ensuring welding process stability and weld quality. Simultaneously, the calcination process completely removes moisture and carbon dioxide from the magnesium oxide and completes volume shrinkage at high temperatures, giving it excellent volume stability and refractoriness in the high-temperature molten pool environment of wire arc welding or flux-cored wire arc welding. It is less prone to decomposition or gas generation, contributing to the formation of stable slag protection and improving weld formation and slag removal.

[0057] Please see Figure 2 , Figure 2 A method for preparing flux according to an embodiment of the present invention includes the following steps:

[0058] S21. Mix the components of the flux in proportion and stir evenly to obtain flux powder;

[0059] S22. Place the flux powder in a heating furnace and heat it to melt it into liquid flux.

[0060] S23. Pour the flux liquid into water and cool it to obtain glassy particles. Crush, sieve and dry the glassy particles to obtain the flux.

[0061] In step S21, the flux comprises the following components in parts by weight: 10-13 parts bauxite, 38-43 parts manganese ore, 18-21 parts calcium aluminate, 8-11 parts fluorite, and 12-15 parts magnesia.

[0062] In step S22, the heating furnace is, for example, an electric arc furnace, with a heating temperature of 1300–1500°C. After all the flux powder has completely melted, it is stirred evenly to obtain a flux liquid. The heating time for the flux powder is not limited here, as long as the flux powder is completely melted and the molten flux is stirred evenly. For example, the heating time for the flux powder is 1 hour.

[0063] In step S23, when crushing the glassy particles, a commonly used crushing device in the art can be used, such as a jaw crusher or a ball mill. For example, the glassy particles can be crushed by vibrating sieving, resulting in a flux particle size of 10-60 mesh. After sieving, the flux particles are dried at 350-400°C to remove moisture. The drying time for the flux particles is not limited here, as long as the moisture is removed. For example, the drying time for the flux particles is 2 hours.

[0064] The flux in this application is prepared using a high-temperature melting process, resulting in a flux with more reliable stability, more uniform composition, less hygroscopicity, and better welding processability.

[0065] This invention relates to a seamless submerged arc welding wire, which is produced by welding a metal powder-based flux encapsulated inside a steel strip and then drawing it. The flux is prepared by melting various ingredients in a furnace at high temperature to a liquid state, then quenching and granulating the molten flux in cold water, drying it, and screening it. This invention, through the combination of the seamless submerged arc welding wire and the flux, ensures a highly efficient and stable welding process, more uniform weld metal deposition, and guarantees that the weld metal meets the requirements for ultra-low diffusible hydrogen, low oxygen content, and good horizontal welding performance.

[0066] The technical solution of the present invention will be described in detail below through several specific embodiments. Unless otherwise stated, the raw materials and reagents used in the following embodiments are all commercially available products, or can be prepared by conventional methods in the art, and the instruments used in the embodiments are all commercially available.

[0067] Example 1

[0068] The seamless submerged arc welding wire in this embodiment is prepared as follows: The flux core powder is weighed and mixed evenly according to the following proportions: 82 parts iron powder, 1.8 parts metallic chromium, 5 parts nickel powder, 2.5 parts ferromolybdenum, 5 parts metallic manganese, 0.3 parts graphite, 0.5 parts rare earth fluoride, 0.8 parts Teflon, and 1.5 parts marble. The flux core is obtained by rolling a strip into a U-shaped groove, filling the U-shaped groove, and closing and welding the gap between the steel strip. The steel strip filled with the flux core is then drawn to reduce its diameter, copper-plated on its surface, and then drawn and polished to obtain the seamless submerged arc welding wire. In this embodiment, the flux core filling rate is 40%, the wire diameter is 5.0 mm, and the copper plating thickness is 0.3 μm. The flux is prepared as follows: The flux is weighed and mixed evenly according to the following proportions: 10 parts bauxite, 43 parts manganese ore, 21 parts calcium aluminate, 8 parts fluorite, and 15 parts magnesia to obtain flux powder. The flux powder is placed in a heating furnace and heated to 1300℃ and kept at that temperature for 1 hour. After the flux powder is completely melted, it is poured into water to cool and obtain glassy particles. The glassy particles are crushed, sieved, and dried at 400℃ for 2 hours to obtain the flux.

[0069] Example 2

[0070] The seamless submerged arc welding wire is prepared as follows in this embodiment: The flux core powder is weighed and mixed evenly according to the following proportions: 80 parts iron powder, 2.2 parts metallic chromium, 6 parts nickel powder, 2.8 parts ferromolybdenum, 4 parts metallic manganese, 0.6 parts graphite, 1 part rare earth fluoride, 1 part Teflon, and 1 part marble. The flux core is then rolled into a U-shaped groove, and the flux core is filled into the U-shaped groove to close and weld the gap in the steel strip. The steel strip filled with the flux core is then drawn to reduce its diameter, copper-plated on its surface, and then drawn and polished to obtain the seamless submerged arc welding wire. In this embodiment, the flux core filling rate is 38%, the wire diameter is 4.0 mm, and the copper plating thickness is 0.4 μm. The flux is prepared as follows in this embodiment: The flux is weighed and mixed evenly according to the following proportions: 11 parts bauxite, 40 parts manganese ore, 20 parts calcium aluminate, 9 parts fluorite, and 14 parts magnesia to obtain the flux powder. The flux powder is placed in a heating furnace and heated to 1500℃ and kept at that temperature for 1 hour. After the flux powder is completely melted, it is poured into water to cool and obtain glassy particles. The glassy particles are crushed, sieved, and dried at 380℃ for 2 hours to obtain the flux.

[0071] Example 3

[0072] The seamless submerged arc welding wire in this embodiment is prepared as follows: The flux core powder is weighed and mixed evenly according to the following proportions: 78 parts iron powder, 2.3 parts metallic chromium, 6.5 parts nickel powder, 3.5 parts ferromolybdenum, 7 parts metallic manganese, 0.4 parts graphite, 0.7 parts rare earth fluoride, 0.8 parts Teflon, and 0.8 parts marble. The flux core is obtained by rolling a strip into a U-shaped groove, filling the U-shaped groove, and closing and welding the gap between the steel strip. The steel strip filled with the flux core is then drawn to reduce its diameter, copper-plated on its surface, and then drawn and polished to obtain the seamless submerged arc welding wire. In this embodiment, the flux core filling rate is 35%, the wire diameter is 3.2 mm, and the copper plating thickness is 0.5 μm. The flux is prepared as follows: The flux is weighed and mixed evenly according to the following proportions: 12 parts bauxite, 38 parts manganese ore, 19 parts calcium aluminate, 10 parts fluorite, and 13 parts magnesia to obtain flux powder. The flux powder is placed in a heating furnace and heated to 1500℃ and kept at that temperature for 1 hour. After the flux powder is completely melted, it is poured into water to cool and obtain glassy particles. The glassy particles are crushed, sieved, and dried at 380℃ for 2 hours to obtain the flux.

[0073] Example 4

[0074] The seamless submerged arc welding wire is prepared as follows in this embodiment: The flux core powder is weighed and mixed evenly according to the following proportions: 75 parts iron powder, 2.5 parts metallic chromium, 7 parts nickel powder, 4 parts ferromolybdenum, 6 parts metallic manganese, 0.5 parts graphite, 0.8 parts rare earth fluoride, 0.5 parts Teflon, and 0.5 parts marble. The flux core is then rolled into a U-shaped groove, and the flux core is filled into the U-shaped groove to close and weld the gap in the steel strip. The steel strip filled with the flux core is then drawn to reduce its diameter, copper-plated on its surface, and then drawn and polished to obtain the seamless submerged arc welding wire. In this embodiment, the flux core filling rate is 32%, the wire diameter is 2.0 mm, and the copper plating thickness is 0.4 μm. The flux is prepared as follows in this embodiment: The flux is weighed and mixed evenly according to the following proportions: 13 parts bauxite, 38 parts manganese ore, 18 parts calcium aluminate, 11 parts fluorite, and 12 parts magnesia to obtain the flux powder. The flux powder is placed in a heating furnace and heated to 1400℃ and kept at that temperature for 1 hour. After the flux powder is completely melted, it is poured into water to cool and obtain glassy particles. The glassy particles are crushed, sieved, and dried at 350℃ for 2 hours to obtain the flux.

[0075] In Examples 1 to 4, the average particle size of iron powder, metallic chromium, nickel powder, ferromolybdenum, and metallic manganese was 40 mesh; the average particle size of marble, graphite, and Teflon was 120 mesh; and the average particle size of bauxite, manganese ore, calcium aluminate, fluorite, and decalcined magnesia was 20 mesh. Fluoride with a particle size of 10–60 mesh was selected after sieving in Examples 1 to 4 for later use.

[0076] The composition of the flux core in the seamless submerged arc welding wires prepared in Examples 1 to 4 of this invention is shown in Table 1, and the composition of the flux prepared in Examples 1 to 4 is shown in Table 2. The seamless submerged arc welding wires and fluxes from Examples 1 to 4 were used in combination for welding performance testing according to the national standard GB / T 36034-2018 Classification Requirements for High-Strength Steel Solid Welding Wires, Flux-Cored Welding Wires and Wire-Fluoride Combinations for Submerged Arc Welding. The welding process is shown in Table 3, the chemical composition of the deposited metal is shown in Table 4, and the mechanical properties and welding process properties of the deposited metal are shown in Table 5. The moisture resistance of the seamless submerged arc welding wires and fluxes was tested. The test method was as follows: the seamless submerged arc welding wires and fluxes were exposed for 24 hours in an environment with a relative humidity of 80% RH and a temperature of 40℃. Welding was then performed using the exposed seamless flux-cored welding wires and fluxes, and the diffusible hydrogen content in the deposited metal was tested. The test results are shown in Table 6.

[0077] Table 1. Composition of the flux core in the seamless submerged arc welding wires prepared in Examples 1 to 4.

[0078]

[0079]

[0080] Table 2 shows the composition of the fluxes prepared in Examples 1 to 4.

[0081]

[0082] Table 3 Welding processes of seamless submerged arc welding wire and flux in Examples 1 to 4

[0083]

[0084] Table 4 Chemical composition of the weld metal in Examples 1 to 4

[0085]

[0086] Table 5 shows the mechanical properties and welding process properties of the deposited metals in Examples 1 to 4.

[0087]

[0088] Table 6. Results of hydrogen diffusion tests on the seamless submerged arc welding wires and fluxes prepared in Examples 1 to 4 after moisture resistance tests.

[0089]

[0090] As shown in Table 5, when welding with the seamless submerged arc welding wire and flux prepared in Examples 1 to 4, the arc stability is good, slag removal is good, the weld bead is beautiful, slag removal is easy, the composition of the deposited metal is stable, the mechanical properties are excellent, and the diffusive hydrogen is ultra-low. As shown in Table 6, when welding with the seamless submerged arc welding wire and flux after moisture resistance testing, the deposited metal still has ultra-low diffusive hydrogen, which can alleviate the hydrogen-induced cracking problem of the deposited metal and improve the welding quality.

[0091] This invention proposes a seamless submerged arc welding wire and flux. The seamless submerged arc welding wire of this invention has the advantages of being able to be copper-plated, having good rust resistance, and good conductivity. Furthermore, the seamless nature of the wire reduces the risk of moisture absorption, allowing for larger coil weights, reducing the frequency of wire replacement, improving work efficiency, and reducing joints in the weld. The flux of this invention features low moisture absorption, good compositional uniformity, and stable welding processability. The combination of the welding wire and flux of this invention results in good welding processability, excellent mechanical properties, ultra-low diffusible hydrogen, low oxygen content in the deposited metal, and good horizontal welding performance.

[0092] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A seamless submerged arc welding wire, characterized in that, The seamless submerged arc welding wire comprises a steel strip and a flux core filled within the steel strip. The surface of the seamless submerged arc welding wire is coated with a copper layer. The flux core comprises the following components in parts by weight: 75-82 parts iron powder, 1.8-2.5 parts metallic chromium, 5-7 parts nickel powder, 2.5-4 parts ferromolybdenum, 4-7 parts metallic manganese, 0.3-0.6 parts graphite, 0.5-1 parts rare earth fluoride, 0.5-1 parts Teflon, and 0.5-1.5 parts marble.

2. The seamless submerged arc welding wire according to claim 1, characterized in that, The steel strip is a low-carbon steel strip, and by mass percentage, the steel strip comprises the following components and the mass percentage of each component are as follows: C≤0.05%, Mn≤0.35%, Si≤0.1%, S≤0.03%, P≤0.03%, with the remainder being Fe and unavoidable impurities.

3. The seamless submerged arc welding wire according to claim 1, characterized in that, The diameter of the seamless submerged arc welding wire is 2.0 to 5.0 mm, and the thickness of the copper plating layer is 0.3 to 0.5 μm.

4. The seamless submerged arc welding wire according to claim 1, characterized in that, The filling rate of the core is 32-40%.

5. A method for preparing a seamless submerged arc welding wire according to any one of claims 1 to 4, characterized in that, Includes the following steps: Weigh and mix the core powder according to the specified ratio to obtain the core. The steel strip is rolled into a U-shaped groove, and the core is filled into the U-shaped groove. The gap of the steel strip is then closed and welded. The steel strip filled with the flux core is drawn to reduce its diameter, then copper-plated on its surface and drawn and polished to obtain a seamless submerged arc welding wire.

6. A flux compatible with the seamless submerged arc welding wire according to any one of claims 1 to 4, characterized in that, The flux comprises the following components in parts by weight: 10-13 parts bauxite, 38-43 parts manganese ore, 18-21 parts calcium aluminate, 8-11 parts fluorite, and 12-15 parts magnesia.

7. A method for preparing the flux according to claim 6, characterized in that, Includes the following steps: The components of the flux are mixed in proportion and stirred evenly to obtain flux powder; The flux powder is placed in a heating furnace and heated to melt it into liquid flux. The flux liquid is poured into water and cooled to obtain glassy particles. The glassy particles are then crushed, sieved, and dried to obtain the flux.

8. The method for preparing flux according to claim 7, characterized in that, When the flux powder is placed in a heating furnace for heating, the temperature of the heating furnace is 1300-1500℃.

9. The method for preparing flux according to claim 7, characterized in that, The flux has a particle size of 10-60 mesh.

10. The method for preparing flux according to claim 7, characterized in that, When the glassy particles are crushed, sieved, and dried, the drying temperature is 350–400°C.

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