Production method of steel wire rod for rare earth microalloying high-strength welding wire

Abstract

The invention discloses a production method of a steel wire rod for a rare earth microalloyed high-strength welding wire. The production method comprises the following steps: 1) preparing raw materials; (2) the smelting process comprises converter smelting, refining treatment and vacuum degassing, the treatment time is controlled to be 15-20 minutes, the hydrogen content is 2 ppm or below, and the nitrogen content is 40 ppm or below; (3) rare earth is added, specifically, after VD vacuum degassing is finished, when the temperature of molten steel is adjusted to 1550-1580 DEG C, rare earth is added; 4) a continuous casting process; 5) rolling process; the wire rod comprises the following chemical components in percentage by mass: 0.08%-0.12% of carbon, 0.20%-0.40% of silicon, 1.20%-1.50% of manganese, less than or equal to 0.02% of phosphorus, less than or equal to 0.005% of sulfur, 0.20%-0.30% of chromium, 0.01%-0.03% of rare earth elements and the balance of Fe and impurities. The invention aims to produce the steel wire rod for the rare earth high-strength welding wire, which is excellent in quality and stable in performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of steel production, and particularly relates to a production method of steel wire rod for rare earth microalloyed high-strength welding wire. Background Art

[0002] In the steel industry system, as a key raw material for welding materials, the quality of the production process of steel wire rod directly affects the welding quality and product performance of many downstream industries, and plays a crucial role in promoting the high-end development of the manufacturing industry.

[0003] In the current rapidly developing modern industrial pattern, frontiers such as aerospace, automotive manufacturing, and ocean engineering have extremely stringent requirements for the performance of welding materials. Rare earth high-strength welding wire, with its unique performance advantages, can significantly improve the strength, toughness, and corrosion resistance of welded joints, and has been widely used in these high-end manufacturing fields. However, when facing the increasing high-quality requirements, the traditional steel wire rod production process exposes many problems that need to be solved urgently.

[0004] Firstly, the poor purity of molten steel is a prominent problem. A large number of inclusions in the steel are likely to cause defects such as pores and cracks during the welding process, seriously affecting the welding quality, and thus reducing the reliability and service life of the welded structure. Secondly, the control accuracy of alloying elements during the smelting process is insufficient, resulting in large fluctuations in the chemical composition of the steel wire rod, making it difficult to ensure the consistency of product performance and unable to meet the strict requirements of large-scale industrial production for product quality stability. Thirdly, there are obvious shortcomings in the addition link of rare earth elements in the traditional process. Neither the best addition method of rare earth elements nor the appropriate addition timing is fully considered, so that the excellent properties of rare earth elements in the steel cannot be fully exerted, greatly restricting the further development and application of rare earth high-strength welding wire. Summary of the Invention

[0005] The purpose of the present invention is to provide a production method of steel wire rod for rare earth microalloyed high-strength welding wire, and produce steel wire rod for rare earth high-strength welding wire with excellent quality and stable performance to meet the urgent needs of modern high-end manufacturing for high-quality welding materials.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A production method of steel wire rod for rare earth microalloyed high-strength welding wire of the present invention includes:

[0008] 1) Raw material preparation:

[0009] High-quality scrap steel: Remove the oil, rust and impurities on the surface of the scrap steel to ensure pure raw materials for subsequent smelting;

[0010] Hot metal: Using blast furnace hot metal as one of the main raw materials, strict pretreatment is carried out on the hot metal; adopting the technology of high-efficiency injection of desulfurizing agents to reduce the sulfur content to below 0.01%; applying advanced dephosphorization processes to precisely control the phosphorus content within 0.02%, laying a solid foundation for smelting high-quality molten steel;

[0011] Alloy raw materials: According to the composition requirements of the target steel grade, prepare high-purity ferromanganese, ferrosilicon, and ferrochromium alloy raw materials; before use, fully bake the alloy raw materials to remove moisture and prevent the introduction of harmful gases during the smelting process, which may affect the quality of the steel;

[0012] 2) Smelting process:

[0013] Converter smelting: Add the pretreated hot metal and high-quality scrap steel to the converter in a scientific ratio; with the help of an advanced automatic control system, precisely regulate the oxygen flow rate and blowing time, and monitor the changes in the composition and temperature of the molten steel in real time, so that the carbon, silicon, and manganese elements in the molten steel are oxidized to the target range; at the same time, adopt an optimized slag-making process to effectively remove the phosphorus and sulfur impurities in the molten steel; at the end of blowing, strictly control the molten steel temperature at 1600 - 1650 °C and the carbon content at 0.08 - 0.12%, providing high-quality molten steel for the subsequent refining process;

[0014] Refining treatment: After the converter taps, the molten steel quickly enters the LF refining furnace. In the LF furnace, add refining slag for deep slag-making refining to further desulfurize, deoxidize, and precisely adjust the composition of the molten steel; by precisely controlling the argon stirring intensity, generally controlled at 0.2 - 0.3 liters / (minute·ton of steel), ensure the uniformity of the molten steel composition and temperature. The refining time is controlled within 30 - 40 minutes, reduce the sulfur content in the molten steel to below 0.005%, effectively remove and modify inclusions, and significantly improve the purity of the molten steel;

[0015] Vacuum degassing: The molten steel refined by LF enters the VD vacuum degassing device. In a high-vacuum environment, the hydrogen and nitrogen gases in the molten steel quickly escape. The treatment time is controlled within 15 - 20 minutes to ensure that the hydrogen content in the molten steel is reduced to below 2 ppm and the nitrogen content is controlled at 40 ppm or below, greatly improving the purity and toughness of the steel;

[0016] 3) Rare earth addition:

[0017] Addition timing: After the VD vacuum degassing is completed, when the temperature of the molten steel in the ladle is adjusted to 1550 - 1580 °C, rare earth addition is carried out;

[0018] Addition method: Use the wire feeding method to add rare earth;

[0019] 4) Continuous casting process:

[0020] Tundish flow control: During continuous casting, a flow control device is used in the tundish to optimize the flow state of the molten steel, promoting the full floating and removal of inclusions. At the same time, the tundish molten steel temperature is strictly controlled at 1520 - 1540 °C to ensure good fluidity of the molten steel and guarantee the forming quality of the billet.

[0021] Mold powder: A mold powder with excellent lubricity, heat transfer performance, and inclusion absorption capacity is selected. The model is Xibao composite mold powder. During the crystallization process, the mold powder forms a uniform and dense slag film on the surface of the billet, which not only improves the surface quality of the billet, reduces surface defects, but also plays a good lubricating role, reduces the friction between the billet and the mold wall, and improves the casting speed and quality.

[0022] Billet cooling: A secondary cooling system is adopted.

[0023] 5) Rolling process:

[0024] Heating system: The billet is heated to a suitable rolling temperature range, generally 1100 - 1150 °C.

[0025] Rolling process: A multi-pass continuous rolling process is adopted. By reasonably distributing the reduction of each pass, the steel billet is gradually deformed into the required wire rod size.

[0026] Laying head cooling: After the wire rod is laid head, the Stelmor cooling process is adopted.

[0027] The chemical composition of the wire rod by mass percentage is as follows: Carbon: The content is controlled at 0.08 - 0.12%, Silicon: The content is 0.20 - 0.40%, Manganese: The content is 1.20 - 1.50%, Phosphorus: The content ≤ 0.02%, Sulfur: The content ≤ 0.005%, Chromium: The content is 0.20 - 0.30%, Rare earth elements: The content is 0.01 - 0.03%, and the rest is Fe and inevitable impurities.

[0028] Further, the high-quality scrap steel includes the high-quality scrap steel produced by screening mechanical processing and the automobile dismantling industry.

[0029] Further, the high vacuum degree is below 67 Pa.

[0030] Further, the rare earth alloy is made into wire materials of specific specifications and slowly and evenly inserted into the molten steel through a high-precision wire feeding machine. Using an automated control system, according to the amount of molten steel and the target rare earth content, the wire feeding speed is accurately controlled to ensure the accuracy of the rare earth addition amount.

[0031] Further, weak cooling is adopted for the secondary cooling of the billet, and the cooling water volume is accurately controlled at 1.5 cubic meters per minute through an intelligent control system. After the wire rod is laid head, on the Stelmor air cooling line, the cooling time is controlled at 15 minutes by adjusting the fan air volume to 80%.

[0032] Furthermore, medium cooling intensity is adopted for secondary cooling of the continuous casting billet, and the cooling water volume is controlled at 1.8 cubic meters per minute; after the wire rod is spun, on the Stelmor air-cooling line, the air volume of the fan is adjusted to 75%, and the cooling time is controlled for 18 minutes.

[0033] Furthermore, the chemical composition of the wire rod by mass percentage is: carbon 0.10%, silicon 0.30%, manganese 1.30%, phosphorus 0.015%, sulfur 0.003%, chromium 0.25%, rare earth elements 0.02%, and the rest is Fe and impurities.

[0034] Furthermore, the chemical composition of the wire rod by mass percentage is: carbon 0.09%, silicon 0.35%, manganese 1.40%, phosphorus 0.012%, sulfur 0.002%, chromium 0.28%, rare earth elements 0.025%, and the rest is Fe and impurities.

[0035] Compared with the prior art, the beneficial technical effects of the present invention are:

[0036] Improve the purity of molten steel: Through a series of collaborative processes such as hot metal pretreatment, converter smelting, LF refining, and VD vacuum degassing, harmful elements and inclusions such as sulfur, phosphorus, hydrogen, and nitrogen in the molten steel are comprehensively and efficiently removed, significantly improving the purity of the molten steel. This directly improves the welding performance of the welding wire, reduces the generation of welding defects, greatly improves the weld quality, and provides reliable material support for high-end welding applications.

[0037] Precisely control the chemical composition: During the entire smelting and refining process, advanced detection equipment and an automated control system are used to achieve precise control of the addition amount and addition timing of alloying elements. This enables the chemical composition of the steel wire rod to remain stable, greatly ensuring the consistency of product performance and meeting the strict requirements of large-scale industrial production for product quality stability.

[0038] Give full play to the role of rare earth: The present invention scientifically and reasonably designs the addition timing and method of rare earth elements, enabling rare earth elements to fully exert their unique advantages in steel, significantly improving the strength, toughness, and fatigue resistance of steel, effectively meeting the harsh requirements of rare earth high-strength welding wires for the performance of steel wire rods, and promoting the wide application of rare earth high-strength welding wires in high-end manufacturing. Specific embodiments

[0039] A production method of a steel wire rod for rare earth microalloyed high-strength welding wire, comprising:

[0040] Raw material preparation:

[0041] High-quality scrap steel: Carefully select high-quality scrap steel produced in industries such as machining and automobile disassembly. These scrap steels have low impurity content, especially extremely low content of harmful elements such as phosphorus and sulfur. Using advanced detection technologies and strict manual sorting processes, thoroughly remove impurities such as oil stains and rust on the surface of the scrap steel to ensure pure raw materials for subsequent smelting.

[0042] Hot metal: Take blast furnace hot metal as one of the main raw materials and conduct strict pretreatment on the hot metal. Adopt the technology of highly efficient injection of desulfurizing agent to reduce the sulfur content to below 0.01%; use advanced dephosphorization processes to precisely control the phosphorus content within 0.02% to lay a solid foundation for smelting high-quality molten steel.

[0043] Alloy raw materials: According to the composition requirements of the target steel grade, prepare high-purity ferroalloys such as ferromanganese, ferrosilicon, and ferrochrome. Before use, fully bake the alloy raw materials to remove moisture and prevent the introduction of harmful gases such as hydrogen during the smelting process, which may affect the quality of the steel.

[0044] Smelting process:

[0045] Converter smelting: Add the pretreated hot metal and high-quality scrap steel to the converter in a scientific ratio. With the help of an advanced automatic control system, precisely regulate the oxygen flow rate and blowing time, and monitor the changes in the composition and temperature of the molten steel in real time, so that elements such as carbon, silicon, and manganese in the molten steel are oxidized to the target range. At the same time, adopt an optimized slag-making process to effectively remove impurities such as phosphorus and sulfur in the molten steel. At the end of blowing, strictly control the molten steel temperature at 1600 - 1650 °C and the carbon content at 0.08 - 0.12% to provide high-quality molten steel for subsequent refining processes.

[0046] Refining treatment: After the converter taps, the molten steel quickly enters the LF refining furnace. In the LF furnace, add carefully prepared refining slag for deep slag-making refining to further desulfurize, deoxidize, and precisely adjust the composition of the molten steel. By precisely controlling the argon stirring intensity, generally controlled at 0.2 - 0.3 L / (min·t of steel), ensure the uniformity of the composition and temperature of the molten steel. The refining time is controlled within 30 - 40 minutes, reduce the sulfur content in the molten steel to below 0.005%, effectively remove and modify inclusions, and significantly improve the purity of the molten steel.

[0047] Vacuum degassing: The molten steel refined by LF enters the VD vacuum degassing device. In an environment of high vacuum (below 67 Pa), gases such as hydrogen and nitrogen in the molten steel quickly escape. The treatment time is controlled within 15 - 20 minutes to ensure that the hydrogen content in the molten steel is reduced to below 2 ppm and the nitrogen content is controlled at 40 ppm or below, greatly improving the purity and toughness of the steel.

[0048] Rare earth addition:

[0049] Timing of addition: After the VD vacuum degassing is completed, when the molten steel temperature in the ladle is adjusted to 1550 - 1580 °C, rare earth addition is carried out. At this time, the purity of the molten steel is high, which can effectively reduce the reaction between rare earth and impurities, improve the rare earth recovery rate, and give full play to the beneficial effects of rare earth elements.

[0050] Method of addition: Advanced wire feeding method is used to add rare earth. The rare earth alloy is made into wire materials of specific specifications and slowly and evenly inserted into the molten steel through a high-precision wire feeder. An automated control system is used to accurately control the wire feeding speed according to the amount of molten steel and the target rare earth content to ensure the accuracy of rare earth addition.

[0051] Continuous casting process:

[0052] Flow control in tundish: During continuous casting, the tundish adopts carefully designed flow control devices such as special-shaped dams and weirs to optimize the flow state of the molten steel and promote the full floating and removal of inclusions. At the same time, the molten steel temperature in the tundish is strictly controlled at 1520 - 1540 °C to ensure good fluidity of the molten steel and guarantee the forming quality of the casting blank.

[0053] Mould powder: Mould powder with excellent lubricity, heat transfer performance and inclusion absorption ability is selected. During the crystallization process, the mould powder forms a uniform and dense slag film on the surface of the casting blank, which not only improves the surface quality of the casting blank, reduces surface defects, but also plays a good lubricating role, reduces the friction between the casting blank and the mould wall, and improves the casting speed and quality.

[0054] Casting blank cooling: A secondary cooling system optimized based on the principles of heat transfer and actual production experience is adopted. According to key parameters such as the cross-sectional size and casting speed of the casting blank, an intelligent control system is used to accurately control the cooling water volume and cooling intensity to ensure uniform cooling of the casting blank, avoid defects such as cracks caused by uneven cooling, and guarantee the internal quality of the casting blank.

[0055] Rolling process:

[0056] Heating system: The casting blank is heated to a suitable rolling temperature range, generally 1100 - 1150 °C. Advanced heating equipment and temperature control systems are used to ensure uniform austenitization of the internal structure of the casting blank. At the same time, the heating time and temperature upper limit are strictly controlled to avoid overheating and overburning of the casting blank, and guarantee good organizational structure and performance of the casting blank before rolling.

[0057] Rolling process: A multi-pass continuous rolling process is adopted. By reasonably distributing the reduction per pass, the steel billet is gradually deformed into the required wire rod size. During the rolling process, an automated control system is used to accurately control the rolling speed and cooling speed, optimize the organizational structure and performance of the wire rod, and improve the strength, toughness and surface quality of the wire rod.

[0058] Wire Spinning and Cooling: After the wire rod is spun, the Stelmor cooling process is adopted. By precisely controlling the air volume of the fans and the cooling time on the air-cooling line, the wire rod undergoes phase transformation at an appropriate cooling rate to obtain an ideal metallographic structure and mechanical properties, meeting the quality requirements of the wire rod for rare earth high-strength welding wires.

[0059] Example 1:

[0060] Raw Material Preparation: 50 tons of high-quality scrap steel is selected. After testing, its phosphorus content is 0.015% and its sulfur content is 0.02%. 100 tons of hot metal from the blast furnace is pretreated. After adopting the process of injecting desulfurizer and dephosphorization, the sulfur content is successfully reduced to 0.008% and the phosphorus content is reduced to 0.015%. 3 tons of high-purity ferromanganese, 2 tons of ferrosilicon, and 1 ton of ferrochromium are prepared. All alloy raw materials are baked before use to remove moisture.

[0061] Smelting Process: The hot metal and scrap steel are added to the converter in proportion and blown with oxygen for smelting. The oxygen flow rate is precisely controlled at 5000 standard cubic meters per hour by using an automated control system, and the blowing time is set at 25 minutes. At the end of blowing, the temperature of the molten steel reaches 1620°C and the carbon content is 0.10%. After the converter taps, the molten steel enters the LF refining furnace. In the LF furnace, 300 kg of refining slag is added, the argon stirring intensity is controlled at 0.2 liters / (minute·ton of steel), and the refining time is 35 minutes. After refining, the sulfur content of the molten steel is reduced to 0.003%. Subsequently, the molten steel enters the VD vacuum degassing device and is treated for 18 minutes in an environment where the vacuum degree is maintained at 50 Pa, the hydrogen content is reduced to 1.5 ppm, and the nitrogen content is reduced to 35 ppm.

[0062] Rare Earth Addition: After the VD vacuum degassing is completed, when the temperature of the molten steel in the ladle is 1560°C, rare earth wire is added using a high-precision wire feeder. The wire feeding speed is controlled at 2 meters per minute, and the addition amount is 0.5 kg / ton of steel to ensure that the rare earth is evenly dissolved in the molten steel.

[0063] Continuous Casting Process: The tundish is equipped with a carefully designed baffle and dam flow control device to control the tundish molten steel temperature at 1530°C. High-quality mold powder is selected, and weak cooling is adopted for the secondary cooling of the casting billet. The cooling water volume is precisely controlled at 1.5 cubic meters per minute through an intelligent control system.

[0064] Rolling Process: The casting billet is heated to 1120°C and a 10-pass continuous rolling process is adopted. The reduction per pass is reasonably distributed by using an automated control system, and the rolling speed and cooling speed are precisely controlled. After the wire rod is spun, on the Stelmor air-cooling line, the air volume of the fans is adjusted to 80%, and the cooling time is controlled at 15 minutes.

[0065] Product performance: The produced steel wire rod has been comprehensively tested. The yield strength is 550 MPa, the tensile strength is 680 MPa, the elongation is 20%, the inclusion rating is grade 1.0, and all performance indicators meet the quality requirements of steel wire rod for rare earth high-strength welding wire. The test results of its chemical composition are as follows: carbon 0.10%, silicon 0.30%, manganese 1.30%, phosphorus 0.015%, sulfur 0.003%, chromium 0.25%, rare earth elements 0.02%, and the rest is Fe and impurities.

[0066] Example 2:

[0067] Raw material preparation: 40 tons of high-quality scrap steel is selected, with a phosphorus content of 0.012% and a sulfur content of 0.018%. 110 tons of hot metal is pretreated, and after treatment, the sulfur content is 0.007% and the phosphorus content is 0.012%. 3.5 tons of ferromanganese, 2.5 tons of ferrosilicon, and 1.2 tons of ferrochromium are prepared. The alloy raw materials are baked before use to ensure their quality.

[0068] Smelting process: During the oxygen blowing smelting process in the converter, the oxygen flow rate is controlled at 4800 standard cubic meters per hour, and the blowing time is 28 minutes. The temperature of the molten steel at the end point reaches 1630 °C, and the carbon content is 0.09%. After the converter taps the steel, the molten steel enters the LF refining furnace. During LF refining, 350 kg of refining slag is added, the argon stirring intensity is controlled at 0.25 liters / (minute·ton of steel), the refining time is 40 minutes, and the sulfur content of the molten steel drops to 0.002%. Subsequently, VD vacuum degassing is carried out, and it is treated for 20 minutes under the condition of a vacuum degree of 60 Pa, the hydrogen content drops to 1.8 ppm, and the nitrogen content drops to 38 ppm.

[0069] Rare earth addition: When the temperature of the molten steel drops to 1570 °C, rare earth is added by a wire feeding machine. The wire feeding speed is set at 2.2 meters per minute, and the addition amount is 0.6 kg / ton of steel to ensure that the rare earth elements are fully incorporated into the molten steel.

[0070] Continuous casting process: The flow control device of the tundish optimizes the flow of the molten steel, and the temperature of the molten steel in the tundish is controlled at 1525 °C. A mold powder with excellent performance is selected, and medium cooling intensity is adopted for the secondary cooling of the casting billet, and the cooling water volume is controlled at 1.8 cubic meters per minute.

[0071] Rolling process: The casting billet is heated to 1130 °C and a 11-pass rolling process is adopted. The reduction of each pass is reasonably controlled, and the rolling speed and cooling speed are precisely controlled by an automated control system. After the wire rod spins off, on the Stelmor air-cooling line, the air volume of the fan is adjusted to 75%, and the cooling time is controlled at 18 minutes.

[0072] Product performance: The yield strength of the steel wire rod is 560 MPa, the tensile strength is 690 MPa, the elongation is 21%, the inclusion rating is 0.8 level, and the product quality is excellent. The test results of its chemical composition are as follows: carbon 0.09%, silicon 0.35%, manganese 1.40%, phosphorus 0.012%, sulfur 0.002%, chromium 0.28%, rare earth elements 0.025%, and the rest is Fe and impurities.

[0073] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for producing a rare earth microalloyed high-strength welding wire steel wire rod, characterized in that: include: 1) Raw material preparation: High-quality scrap steel: remove oil, rust and other impurities on the surface of scrap steel to ensure pure raw materials for subsequent smelting; Molten iron: Using blast furnace molten iron as one of the main raw materials, the molten iron is strictly pretreated; using efficient spraying desulfurizer technology to reduce the sulfur content to below 0.01%; using advanced dephosphorization technology to accurately control the phosphorus content within 0.02%, laying a solid foundation for smelting high-quality molten steel; Alloy raw materials: Prepare high-purity ferromanganese, ferrosilicon and ferrochrome alloy raw materials according to the composition requirements of the target steel grade; fully bake the alloy raw materials before use to remove moisture and prevent the introduction of harmful gases during the smelting process, which may affect the quality of the steel; 2) Smelting process: Converter smelting: pre-treated molten iron and high-quality scrap steel are added to the converter in a scientific ratio; with the help of advanced automatic control systems, the oxygen flow rate and blowing time are precisely controlled, and the composition and temperature changes of the molten steel are monitored in real time to oxidize the carbon, silicon and manganese elements in the molten steel to the target range; at the same time, an optimized slag-making process is adopted to effectively remove phosphorus and sulfur impurities in the molten steel; at the end of blowing, the temperature of the molten steel is strictly controlled at 1600-1650℃, and the carbon content is controlled at 0.08-0.12%, providing high-quality molten steel for subsequent refining processes; Refining treatment: After the converter taps out, the molten steel quickly enters the LF refining furnace. In the LF furnace, refining slag is added for deep slag making and refining, further desulfurization and deoxidation, and precise adjustment of the molten steel composition; by precisely controlling the argon stirring intensity, generally controlled at 0.2-0.3 liters / (minute·ton of steel), the composition and temperature of the molten steel are ensured to be uniform, and the refining time is controlled at 30-40 minutes to reduce the sulfur content in the molten steel to below 0.005%, effectively remove and denature inclusions, and significantly improve the purity of the molten steel; Vacuum degassing: After LF refining, the molten steel enters the VD vacuum degassing device. In a high vacuum environment, hydrogen and nitrogen gases in the molten steel escape rapidly. The processing time is controlled within 15-20 minutes to ensure that the hydrogen content in the molten steel drops below 2ppm and the nitrogen content is controlled below 40ppm, which greatly improves the purity and toughness of the steel. 3) Rare earth addition: Adding time: After VD vacuum degassing, when the temperature of molten steel in the ladle is adjusted to 1550-1580℃, rare earth is added; Adding method: Rare earth is added by wire feeding method; 4) Continuous casting process: Tundish flow control: During the continuous casting process, the tundish uses a flow control device to optimize the flow state of the molten steel and promote the full floating and removal of inclusions; at the same time, the temperature of the molten steel in the tundish is strictly controlled at 1520-1540℃ to ensure that the molten steel has good fluidity and guarantee the quality of the ingot molding; Mold protection slag: The mold protection slag with excellent lubricity, heat transfer and inclusion absorption ability is selected. The model is Xibao composite protection slag. During the crystallization process, the protection slag forms a uniform and dense slag film on the surface of the ingot, which not only improves the surface quality of the ingot and reduces surface defects, but also plays a good lubricating role, reduces the friction between the ingot and the crystallizer wall, and improves the billet drawing speed and quality; Ingot cooling: secondary cooling system is adopted; 5) Rolling process: Heating system: Heat the ingot to a suitable rolling temperature range, generally 1100-1150℃; Rolling process: adopt multi-pass continuous rolling process, and reasonably distribute the reduction amount of each pass to gradually deform the steel billet into the required wire rod size; Wire drawing cooling: After the wire rod is drawn, the Stelmor cooling process is adopted; The chemical composition of the wire rod by mass percentage is: carbon: content controlled at 0.08-0.12%, silicon: content at 0.20-0.40%, manganese: content at 1.20-1.50%, phosphorus: content ≤0.02%, sulfur: content ≤0.005%, chromium: content at 0.20-0.30%, rare earth elements: content at 0.01-0.03%, and the rest is Fe and unavoidable impurities.

2. The method for producing rare earth microalloyed high-strength welding wire steel wire rod according to claim 1, characterized in that: The high-quality scrap steel includes high-quality scrap steel produced by screening mechanical processing and automobile dismantling industries.

3. The method for producing rare earth microalloyed high-strength welding wire steel wire rod according to claim 1, characterized in that: The high vacuum degree is below 67 Pa.

4. The method for producing rare earth microalloyed high-strength welding wire steel wire rod according to claim 1, characterized in that: The rare earth alloy is made into wires of specific specifications and slowly and evenly inserted into the molten steel by a high-precision wire feeder. An automated control system is used to precisely control the wire feeding speed according to the amount of molten steel and the target rare earth content, ensuring the accuracy of the rare earth addition.

5. The method for producing rare earth microalloyed high-strength welding wire steel wire rod according to claim 1, characterized in that: The secondary cooling of the ingot adopts a weak cooling system, and the cooling water volume is precisely controlled at 1.5 cubic meters per minute through an intelligent control system. After the wire rod is spun, on the Stelmore air cooling line, the fan air volume is adjusted to 80% to control the cooling time to 15 minutes.

6. The method for producing rare earth microalloyed high-strength welding wire steel wire rod according to claim 1, characterized in that: The secondary cooling of the ingot adopts medium cooling intensity, and the cooling water volume is controlled at 1.8 cubic meters per minute; after the wire rod is spun, on the Stelmore air cooling line, the fan air volume is adjusted to 75%, and the cooling time is controlled to 18 minutes.

7. The method for producing rare earth microalloyed high-strength welding wire steel wire rod according to claim 1, characterized in that: The chemical composition of the wire rod by mass percentage is: 0.10% carbon, 0.30% silicon, 1.30% manganese, 0.015% phosphorus, 0.003% sulfur, 0.25% chromium, 0.02% rare earth elements, and the rest is Fe and impurities.

8. The method for producing rare earth microalloyed high-strength welding wire steel wire rod according to claim 1, characterized in that: The chemical composition of the wire rod by mass percentage is: 0.09% carbon, 0.35% silicon, 1.40% manganese, 0.012% phosphorus, 0.002% sulfur, 0.28% chromium, 0.025% rare earth elements, and the rest is Fe and impurities.