Preparation method of novel low-alloy steel solid welding wire

Abstract

The invention discloses a preparation method of a novel low-alloy steel solid welding wire. The preparation method comprises the following steps of S1, raw material smelting, S2, a hot working stage, S3, a cold working stage, S4, surface treatment and S5, quality detection. During raw material selection, C-Mn-Si is adopted as a basic alloy, the content of C is 0.06-0.12%, the content of Mn is 1.2-1.6%, then a Ti-B microalloy is added, the hardenability is improved, the O / N content is limited at the same time, then a two-stage refining process combining vacuum induction melting and electroslag remelting is adopted, the melting temperature, time and refining slag system components are regulated and controlled, and the hardness of the alloy is improved. The method comprises the following steps: preparing a copper plating solution through equipment, deeply removing harmful impurities such as S and P, promoting floating and size refinement of inclusions by applying an electromagnetic stirring technology, remarkably improving the purity of a metal matrix, thereby improving the purity of raw material smelting, proportioning the copper plating solution through the equipment, setting the parameters of the copper plating equipment to be 10-15A / dm in current density and 2-3mu m in plating thickness, and carrying out a copper plating process on a welding wire.

Description

Technical Field

[0001] This invention relates to the field of solid welding wire preparation technology, specifically to a method for preparing a novel low-alloy steel solid welding wire. Background Technology

[0002] Low-alloy steel solid welding wire, as a crucial material in welding technology, exhibits immense application potential and innovation space in fields such as shipbuilding and marine engineering, bridge construction, new energy vehicles, nuclear power plants, infrastructure, and wind power generation. In the shipbuilding and marine sector, the complex environment of high salt spray and strong corrosion places stringent demands on the corrosion resistance of welding materials. Bridge engineering faces the challenges of large spans and high stresses, requiring high strength and toughness of welded joints. New energy vehicles pursue lightweight design, and the application of new materials such as aluminum alloys and high-strength steel necessitates suitable welding solutions. Nuclear power plant construction has extremely high safety requirements, necessitating strict control of welding defects and hydrogen content. Infrastructure projects are large-scale, requiring a balance between cost and quality. Wind power generation demands welding wires with high strength and fatigue resistance to withstand the harsh conditions of high-altitude operation of wind turbine towers. However, during the smelting of raw materials, often only the raw materials are smelted, without removing harmful S / P impurities, thus reducing the quality of the smelted raw materials. Furthermore, during the surface treatment of the welding wire, only a single anti-rust coating is applied, resulting in an uneven surface. This increases the wire feeding resistance, leads to unstable arc morphology, and significantly increases the spatter rate. Moreover, after the welding wire is prepared, only its shape is inspected; the internal composition is not thoroughly examined, thus increasing the defect rate in welding wire production. Therefore, "during the smelting of raw materials, only the raw materials are typically smelted without removing harmful S / P impurities, thereby reducing the quality of the raw material smelting. Furthermore, during the surface treatment of the welding wire, only a single anti-rust coating is applied, resulting in an uneven surface. This increases the wire feeding resistance, leads to unstable arc morphology, and significantly increases the spatter rate. Moreover, after the welding wire is prepared, only its shape is inspected; the internal composition is not thoroughly examined, thus increasing the defect rate in welding wire production." Specifically, this manifests in the following aspects: (1) When the raw materials are melted, they are usually melted but the harmful impurities S / P are not removed, which reduces the quality of the raw material melting. (2) When the welding wire is surface treated, only a single anti-rust coating is applied, which results in an uneven surface of the welding wire, which increases the wire feeding resistance and causes the arc shape of the welding wire to be unstable, resulting in a significant increase in the spatter rate. (3) After the welding wire is prepared, only the shape of the welding wire is simply inspected, and the internal composition cannot be deeply inspected, which increases the defect rate of the welding wire production. Summary of the Invention

[0003] The purpose of this invention is to provide a novel method for preparing solid low-alloy steel welding wire, in order to solve the problems mentioned in the background art regarding the current method for preparing solid welding wire: (1) when the raw materials are melted, the raw materials are usually melted but the harmful impurities S / P are not removed, thereby reducing the quality of the raw material melting; (2) when the welding wire is surface treated, only a single anti-rust coating is applied, resulting in an uneven surface of the welding wire, which increases the wire feeding resistance and causes the arc shape of the welding wire to be unstable, resulting in a significant increase in the spatter rate; (3) after the welding wire is prepared, only the shape of the welding wire is simply inspected, and the internal composition cannot be deeply inspected, thereby increasing the defect rate of the welding wire production.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a novel low-alloy steel solid welding wire, the preparation process comprising the following steps: S1, Raw material smelting S1.1 Alloy design: ① C-Mn-Si base alloy (C: 0.06-0.12%, Mn: 1.2-1.6%), ② Ti-B microalloying added (Ti: 0.02-0.05%, B 0.001-0.003%), ③ O / N content limited (O≤30ppm, N≤60ppm). S1.2 Smelting process: ① Electric arc furnace primary refining, ② Vacuum induction melting combined with electroslag remelting two-stage refining process, ③ Electromagnetic stirring technology. S1.3 Continuous casting into Φ150mm steel billets, superheat control 20~30℃. S2, Hot Processing Stage S2.1 Hot rolling forming: ① The walking beam furnace is heated to 1200℃ and held for more than 2 hours. ② The roughing rolling temperature is ≥1050℃ and the finishing rolling temperature is 880-920℃. ③ The laminar flow cooling rate is 15-20℃ / s. S2.2 Wire rod treatment: ① The wire rod is cooled to room temperature in a Steyrmo controlled cooling line. ② The surface is shot blasted to Sa2.5 cleanliness level. S3, Cold processing stage S3.1 Drawing and diameter reduction: ① Pickling process, HCl 18% + corrosion inhibitor (temperature 70℃, time 15min), ② Drawing passes: Φ8mm→Φ5.5mm→Φ3.2mm→Φ1.6mm (reduction rate per pass ≤25%), ③ Use polycrystalline die (half die angle 8°~12°) to reduce work hardening. S3.2 Intermediate annealing: ① Hydrogen-protected annealing (750℃×90s) to relieve stress, ② Hardness control HV180~220. S4, Surface Treatment S4.1 Copper plating process: ① Copper plating solution preparation, ② Current density 10~15A / dm², plating thickness 2~3μm, ③ Passivation treatment (chromate solution, pH 3.5~4.5); S4.2 Finished product treatment: ① Tension control winding, tension 20-30N, ② Nano coating, ③ Welding current waveform control technology, ④ Rust-preventive oil spraying, oil film thickness 1~2μm. S5, Quality Inspection S5.1 Chemical composition testing, using a direct-reading spectrometer; S5.2 Mechanical properties, ① Tensile strength testing, using a universal testing machine; ② Dimensional accuracy, using a laser diameter gauge; S5.3 Welding performance, ① Wire feeding stability, using an automated wire feeding test bench; ② Spatter rate ≤3% (CO2 shielded welding); ④ Coating quality, cross-cut test, copper layer adhesion ≥3N / mm².

[0005] Preferably, the welding wire strength and toughness are matched by Ti-B microalloying, the impact energy at -20℃ is ≥80J, the wire breakage rate is reduced to below 0.5% by optimizing the drawing process, and the conductivity is improved by 15% by improving the copper plating process, with a resistance ≤0.18Ω / m.

[0006] Preferably, the pickling process is carried out at a temperature of 70°C for 15 minutes.

[0007] Preferably, the electroplating solution formula is CuSO4·5H2O 200g / L + H2SO4 50g / L.

[0008] Preferably, the induction heating power formula for the vacuum induction melting is P=m Cp ΔT / tη+Ploss.

[0009] Preferably, in the induction heating power formula for vacuum induction melting, P is the total power in kW, m is the mass of the molten metal in kg, Cp is the specific heat capacity of the metal in kJ / kg·℃, where steel ≈ 0.49, ΔT is the target temperature rise in ℃, η is the thermal efficiency, typically 0.6~0.8, and Ploss is the system heat loss in kW.

[0010] Preferably, the formula for calculating the pumping speed required to maintain the vacuum level in the vacuum induction melting furnace is S=Q / P, where S is the effective pumping speed of the pump group, with the unit being m³ / s, Q is the total gas load of the system, with the unit being Pa·m³ / s, and P is the target vacuum level, with the unit being Pa.

[0011] Preferably, the empirical formula for adjusting the welding current waveform is I=kd, where I is the welding current in A, d is the welding electrode diameter in mm, and k is a coefficient, typically 40 for ordinary welding electrodes and 20 for thin plate welding electrodes.

[0012] Preferably, the judgment parameters of the direct-reading spectrometer are as follows: ultraviolet region: 140~400nm for detecting C, P, and S elements; visible region: 400~800nm ​​for detecting Fe, Mn, and Cr; near-infrared region: 800~2500nm for detecting N and O.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention improves the purity of the raw material by using a C-Mn-Si base alloy with a C content of 0.06-0.12% and a Mn content of 1.2-1.6%, and then adding Ti-B microalloying to improve hardenability while limiting the O / N content. Then, a two-stage refining process combining vacuum induction melting and electroslag remelting is adopted. By controlling the melting temperature, time and refining slag composition, harmful impurities such as S and P are deeply removed. At the same time, electromagnetic stirring technology is used to promote the flotation and size refinement of inclusions, significantly improving the purity of the metal matrix, thereby improving the purity of the raw material smelting.

[0014] 2. This invention involves preparing a copper plating solution using appropriate equipment, setting the equipment parameters to a current density of 10-15 A / dm² and a plating thickness of 2-3 μm, and then performing a copper plating process on the welding wire. Following this, a chromate solution is used for passivation treatment. Tension control is then applied during wire take-up, maintaining a tension of 20-30 N. A surface nano-coating treatment is then applied to improve the surface smoothness and conductivity of the welding wire. Combined with an optimized shielding gas composition design, a stable arc morphology is constructed. Welding current waveform control technology enables precise control of the droplet transfer process, enhancing welding stability. Furthermore, the arc waveform control technology reduces wire feeding resistance, optimizes the arc morphology, and results in a more uniform droplet transfer, significantly reducing spatter and improving welding efficiency.

[0015] 3. This invention uses a direct-reading spectrometer for chemical composition detection. It detects C, P, and S elements in the ultraviolet region (140-400nm), Fe, Mn, and Cr in the visible region (400-800nm), and N and O in the near-infrared region (800-2500nm). Then, a universal testing machine and a laser diameter gauge are used to test the tensile strength and dimensional accuracy of the welding wire. Next, an automated wire feeding test bench is used to test the wire feeding stability. Then, CO2 shielded welding is used to detect the spatter rate. Finally, the cross-cut adhesion method is used to monitor the copper layer adhesion. This allows for the detection of the chemical composition and working condition of the welding wire, improving the comprehensiveness of welding wire testing and the success rate of welding wire production. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the manufacturing process of the solid welding wire of the present invention. Figure 2 This is a diagram of the core operating logic code for the vacuum induction melting furnace of the present invention; Figure 3 This is a diagram showing the operational logic code of the electroslag remelting two-stage refining system of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1: Please see Figures 1-3 A method for preparing a novel low-alloy steel solid welding wire, the preparation process of which includes the following steps: S1, Raw material smelting S1.1 Alloy Design: ① C-Mn-Si base alloy (C: 0.06-0.12%, Mn: 1.2-1.6%), ② Ti-B microalloying added (Ti: 0.02-0.05%, B 0.001-0.003%), ③ O / N content limited (O≤30ppm, N≤60ppm). S1.2 Melting Process: ① Electric arc furnace primary refining, ② Vacuum induction melting combined with electroslag remelting two-stage refining process, ③ Electromagnetic stirring technology employed. S1.3 is continuously cast into Φ150mm steel billets, with superheat controlled at 20~30℃. In the selection of raw materials, C-Mn-Si is used as the base alloy, with C content of 0.06-0.12% and Mn content of 1.2-1.6%. Then, Ti-B microalloying is added to improve hardenability, while limiting O / N content. Then, a two-stage refining process combining vacuum induction melting and electroslag remelting is adopted. By controlling the melting temperature, time and refining slag composition, harmful impurities such as S and P are deeply removed. At the same time, electromagnetic stirring technology is used to promote the flotation and size refinement of inclusions, significantly improving the purity of the metal matrix, thereby improving the purity of raw material smelting. S2, Hot Processing Stage S2.1 Hot rolling forming: ① Heating to 1200℃ in a walking beam furnace and holding for more than 2 hours; ② Rough rolling opening temperature ≥1050℃, finishing rolling final temperature 880-920℃; ③ Laminar cooling rate 15-20℃ / s. S2.2 Wire rod treatment: ① Cooling to room temperature in a Steyrmo controlled cooling line; ② Surface shot blasting treatment with Sa2.5 cleanliness. After the raw material is smelted, it is heated to 1200℃ in a walking beam furnace and held for more than 2 hours. Then, the raw material is hot rolled to form a rough rolling opening temperature ≥1050℃ and a finishing rolling final temperature 880-920℃. Finally, the laminar cooling rate is controlled at 15-20℃ to obtain bainite and acicular ferrite structures. Then, it is cooled to room temperature using a Steyrmo controlled cooling line and then shot blasted on the surface. S3, Cold processing stage S3.1 Drawing and Reduction: ① Pickling process: HCl 18% + corrosion inhibitor (temperature 70℃, time 15min); ② Drawing passes: Φ8mm→Φ5.5mm→Φ3.2mm→Φ1.6mm (reduction rate per pass ≤25%); ③ Use polycrystalline die (half-die angle 8°~12°) to reduce work hardening. S3.2 Intermediate Annealing: ① Hydrogen-protected annealing (750℃×90s) to relieve stress; ② Hardness control HV180~220. The raw material is pickled using HCl 18% + corrosion inhibitor, then drawn using a drawing machine. The drawing passes are Φ8mm→Φ5.5mm→Φ3.2mm→Φ1.6mm. Next, a polycrystalline die is used to reduce work hardening, and then hydrogen-protected annealing is used to relieve stress, controlling the hardness to HV180~220. S4, Surface Treatment S4.1 Copper plating process: ① Prepare copper plating solution; ② Current density 10~15A / dm²; plating thickness 2~3μm; ③ Passivation treatment (chromate solution, pH...) 3.5~4.5), S4.2, Finished product processing: ① Tension control take-up, tension 20-30N, ② Nano coating, ③ Welding current waveform control technology, ④ Anti-rust oil spraying, oil film thickness 1~2μm. The copper plating solution is prepared using equipment, and the copper plating equipment parameters are set to a current density of 10~15A / dm² and a plating thickness of 2~3μm. The welding wire is then copper-plated, and passivated using a chromate solution. Tension control take-up is then used, with tension controlled at 20-30N. A surface nano coating is then applied to improve the surface smoothness and conductivity of the welding wire. Combined with optimized shielding gas composition design, a stable arc morphology is constructed. Welding current waveform control technology is used to achieve precise control of the droplet transfer process, enhancing the stability of the welding process. Arc waveform control technology reduces wire feeding resistance, optimizes the arc morphology, makes droplet transfer more uniform, significantly reduces spatter rate, and significantly improves welding efficiency. S5, Quality Inspection S5.1 Chemical composition analysis was performed using a direct-reading spectrometer. S5.2 Mechanical properties: ① Tensile strength testing was conducted using a universal testing machine; ② Dimensional accuracy was assessed using a laser diameter gauge. S5.3 Welding performance: ① Wire feeding stability was tested using an automated wire feeding test bench; ② Spatter rate was ≤3% (CO2 shielded welding); ④ Coating quality was assessed using the cross-cut test, with copper layer adhesion ≥3N / mm². Then, a direct-reading spectrometer was used for chemical composition analysis, detecting C, P, and S elements in the ultraviolet region (140~400nm) and in the visible region... Fe, Mn, and Cr are detected at 400-800 nm, and N and O are detected at 800-2500 nm near-infrared. Then, the tensile strength and dimensional accuracy of the welding wire are tested using a universal testing machine and a laser diameter gauge. Next, the wire feeding stability is tested using an automated wire feeding test bench. Then, the spatter rate is tested using CO2 shielded welding. Finally, the copper layer adhesion is monitored by cross-cut method. This allows for the detection of the chemical composition and working condition of the welding wire, improving the comprehensiveness of welding wire inspection and the success rate of welding wire production.

[0019] In this embodiment: Ti-B microalloying achieves a balance between strength and toughness of the welding wire, with an impact energy of ≥80J at -20℃. Optimized drawing process reduces the wire breakage rate to below 0.5%, and improved copper plating process increases conductivity by 15%, resulting in a resistance of ≤0.18Ω / m.

[0020] In this embodiment, the pickling process is carried out at a temperature of 70°C for 15 minutes.

[0021] In this embodiment, the electroplating solution formula is CuSO4·5H2O 200g / L + H2SO4 50g / L.

[0022] In this embodiment: the induction heating power formula for vacuum induction melting is P=m Cp ΔT / tη+Ploss.

[0023] In this embodiment: In the induction heating power formula for vacuum induction melting, P is the total power in kW, m is the mass of the molten metal in kg, Cp is the specific heat capacity of the metal in kJ / kg·℃, where steel ≈ 0.49, ΔT is the target temperature rise in ℃, η is the thermal efficiency, usually 0.6~0.8, and Ploss is the system heat loss in kW.

[0024] In this embodiment: the formula for calculating the pumping speed required to maintain the vacuum level in the vacuum induction melting furnace is S=Q / P, where S is the effective pumping speed of the pump group, with the unit being m³ / s, Q is the total gas load of the system, with the unit being Pa·m³ / s, and P is the target vacuum level, with the unit being Pa.

[0025] In this embodiment: the empirical formula for the electrode diameter for welding current waveform control is I=kd, where I is the welding current in A, d is the electrode diameter in mm, and k is a coefficient, generally 40 for ordinary electrodes and 20 for thin plate electrodes.

[0026] In this embodiment: the judgment parameters of the direct-reading spectrometer are as follows: ultraviolet region: 140~400nm for detecting C, P, and S elements; visible region: 400~800nm ​​for detecting Fe, Mn, and Cr; near-infrared region: 800~2500nm for detecting N and O.

[0027] Example 2: As shown in the figure, unlike Example 1, the preparation method of this novel low-alloy steel solid welding wire includes the following steps: ① The welding wire raw material is fed into a vacuum furnace for smelting, and then the smelted raw material is cast into an ingot. ② Impurities on the surface of the ingot are removed using grinding equipment, and then the ingot is fed into a forging machine to be forged into a square billet. ③ The square billet is fed into a rolling mill for rolling to obtain wire rod, and then the wire rod is fed into a wire drawing machine for drawing to obtain welding wire. ④ The welding wire is fed into a special cutting device for cutting to obtain welding wire strips, then the welding wire strips are bundled together, and finally the welding wire strips are packaged. In step ①, pure iron and a uniformly mixed nickel, chromium and molybdenum are added first when smelting the raw material in the vacuum furnace, and after melting... A mixture of carbon, silicon, manganese, sulfur, phosphorus, and titanium is added. The melting temperature is 1170-1200 degrees Celsius, and the melting time is 1-1.6 hours. Argon gas is introduced into the vacuum furnace during melting. The raw material ratio for vacuum furnace smelting is 7.0%-9.0% nickel, 0.5%-1.4% chromium, 0.5%-1.2% molybdenum, 0.08%-0.12% carbon, 0.01%-0.1% silicon, 0.6%-1.0% manganese, 0.01%-0.1% sulfur, 0.01%-0.1% phosphorus, and 0.02%-0.05% titanium, with the remainder being pure iron.

[0028] In summary, compared to Example 2, Example 1 uses a C-Mn-Si base alloy with a C content of 0.06-0.12% and a Mn content of 1.2-1.6% in the raw material selection. Ti-B microalloying is then added to improve hardenability while limiting the O / N content. A two-stage refining process combining vacuum induction melting and electroslag remelting is then employed. By controlling the melting temperature, time, and refining slag composition, harmful impurities such as S and P are deeply removed. Simultaneously, electromagnetic stirring technology is used to promote the flotation and size refinement of inclusions, significantly improving the purity of the metal matrix and thus enhancing the purity of the raw material smelting.

[0029] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0030] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a novel low-alloy steel solid welding wire, characterized in that: Its preparation method includes the following steps: S1, Raw material smelting S1.1 Alloy design: ① C-Mn-Si base alloy: C: 0.06-0.12%, Mn: 1.2-1.6%; ② Ti-B microalloying: Ti: 0.02-0.05%, B: 0.001-0.003%; ③ O / N content limited: O ≤ 30ppm, N ≤ 60ppm. S1.2 Smelting process: ① Electric arc furnace primary refining; ② Vacuum induction melting combined with electroslag remelting two-stage refining process; ③ Electromagnetic stirring technology. S1.3 Continuous casting into Φ150mm steel billets, superheat control 20~30℃. S2, Hot Processing Stage S2.1 Hot rolling forming: ① The walking beam furnace is heated to 1200℃ and held for more than 2 hours. ② The roughing rolling temperature is ≥1050℃ and the finishing rolling temperature is 880-920℃. ③ The laminar flow cooling rate is 15-20℃ / s. S2.2 Wire rod treatment: ① The wire rod is cooled to room temperature in a Steyrmo controlled cooling line. ② The surface is shot blasted to Sa2.5 cleanliness level. S3, Cold processing stage S3.1 Drawing and diameter reduction: ① Pickling process: HCl 18% + corrosion inhibitor, temperature 70℃, time 15min; ② Drawing passes: Φ8mm→Φ5.5mm→Φ3.2mm→Φ1.6mm, with a reduction rate of ≤25% per pass; ③ Use of polycrystalline die, i.e., half die angle 8°~12°, to reduce work hardening; S3.2 Intermediate annealing: ① Hydrogen-protected annealing at 750℃×90s to relieve stress; ② Hardness control HV180~220. S4, Surface Treatment S4.1 Copper plating process: ① Copper plating solution preparation, ② Current density 10~15A / dm², plating thickness 2~3μm, ③ Passivation treatment: chromate solution, pH 3.5~4.5; S4.2 Finished product treatment: ① Tension control winding, tension 20-30N, ② Nano coating, ③ Welding current waveform control technology, ④ Rust-preventive oil spraying, oil film thickness 1~2μm; S5, Quality Inspection S5.1 Chemical composition testing, using a direct-reading spectrometer; S5.2 Mechanical properties, ① Tensile strength testing, using a universal testing machine; ② Dimensional accuracy, using a laser diameter gauge; S5.3 Welding performance, ① Wire feeding stability, using an automated wire feeding test bench; ② Spatter rate ≤3%, CO2 shielded welding; ④ Coating quality, cross-cut test, copper layer adhesion ≥3N / mm².

2. The method for preparing a novel low-alloy steel solid welding wire according to claim 1, characterized in that: Ti-B microalloying achieves a balance between strength and toughness in the welding wire, with an impact energy of ≥80J at -20℃. Optimized drawing process reduces wire breakage rate to below 0.5%, and improved copper plating process increases conductivity by 15%, resulting in a resistance of ≤0.18Ω / m.

3. The method for preparing a novel low-alloy steel solid welding wire according to claim 1, characterized in that: The pickling process is carried out at a temperature of 70°C for 15 minutes.

4. The method for preparing a novel low-alloy steel solid welding wire according to claim 1, characterized in that: The electroplating solution formula is CuSO4·5H2O 200g / L + H2SO4 50g / L.

5. The method for preparing a novel low-alloy steel solid welding wire according to claim 1, characterized in that: The induction heating power formula for vacuum induction melting is P=m Cp ΔT / tη+Ploss.

6. The method for preparing a novel low-alloy steel solid welding wire according to claim 5, characterized in that: In the induction heating power formula for vacuum induction melting, P is the total power in kW, m is the mass of the molten metal in kg, Cp is the specific heat capacity of the metal in kJ / kg·℃, where steel ≈ 0.49, ΔT is the target temperature rise in ℃, η is the thermal efficiency, usually 0.6~0.8, and Ploss is the system heat loss in kW.

7. The method for preparing a novel low-alloy steel solid welding wire according to claim 1, characterized in that: The formula for calculating the pumping speed required to maintain the vacuum level in the vacuum induction melting furnace is S=Q / P, where S is the effective pumping speed of the pump group, with the unit being m³ / s, Q is the total gas load of the system, with the unit being Pa·m³ / s, and P is the target vacuum level, with the unit being Pa.

8. The method for preparing a novel low-alloy steel solid welding wire according to claim 1, characterized in that: The empirical formula for adjusting the welding current waveform is I=kd, where I is the welding current in A, d is the welding electrode diameter in mm, and k is a coefficient, typically 40 for ordinary welding electrodes and 20 for thin plate welding electrodes.

9. The method for preparing a novel low-alloy steel solid welding wire according to claim 1, characterized in that: The judgment parameters of the direct-reading spectrometer are as follows: ultraviolet region: 140~400nm for detecting C, P, and S elements; visible region: 400~800nm ​​for detecting Fe, Mn, and Cr; near-infrared region: 800~2500nm for detecting N and O.

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