High-performance nickel-based welding wire and preparation process thereof

Abstract

The invention discloses a high-performance nickel-based welding wire and a preparation process thereof, and particularly relates to the field of welding materials, a specific material formula is selected, and the prepared nickel-based welding wire makes remarkable breakthrough in the aspects of mechanical property, corrosion resistance, cost optimization and environmental protection. And in the aspect of mechanical properties, the tensile strength, the yield strength and the impact toughness of the welding wire are improved by 25%-30%, 20%-25% and 30%-35% respectively, and the bearing capacity and the safety of a welding structure are effectively enhanced. And in the aspect of corrosion resistance, the corrosion rate of the welding wire in seawater, strong acid and strong alkali media is greatly reduced, and the service life of a welding structure is prolonged. And in the aspect of cost, by optimizing the raw material utilization rate and the production process, the production efficiency is improved by 30%-35%, the comprehensive production cost is reduced by 10%-15%, and the market competitiveness is improved. And in the aspect of environmental protection, an energy-saving and emission-reducing technology is adopted, the energy consumption is reduced by 20%-25%, the waste is reduced by 25%-30%, and meanwhile, the environmental protection requirement is met by using the non-toxic passivation solution.

Description

Technical Field

[0001] This invention relates to the field of welding materials, and in particular to a high-performance nickel-based welding wire and its preparation process. Background Technology

[0002] Nickel-based welding wire plays a crucial role in numerous industrial sectors as an important welding material. Due to the excellent corrosion resistance, high-temperature strength, and oxidation resistance of nickel-based alloys, nickel-based welding wire is widely used in industries with extremely high material performance requirements, such as chemical, aerospace, marine engineering, and energy.

[0003] Currently, nickel-based welding wire preparation processes mainly include smelting, powder metallurgy, and flux-cored welding wire preparation. During smelting and processing, the segregation of alloying elements is difficult to completely avoid. Powder metallurgy welding wires may develop internal porosity and other defects during sintering. In flux-cored welding wire preparation, the bonding strength between the flux core and the outer sheath is sometimes difficult to guarantee, potentially leading to flux core detachment during welding. These problems result in uneven chemical composition, internal porosity defects, and flux core detachment, affecting welding quality and joint reliability. These defects reduce the strength, sealing performance, and mechanical properties of the welded joint, increasing the risk of cracks and porosity during welding, thereby reducing the stability and safety of the welded structure and impacting the overall product performance and long-term reliability. Summary of the Invention

[0004] This invention addresses the challenges of completely avoiding segregation of alloying elements during smelting and processing, the potential for internal porosity and other defects in powder metallurgy welding wires during sintering, and the difficulty in guaranteeing the bonding strength between the flux core and outer sheath in flux-cored welding wire preparation methods, which can lead to flux core detachment during welding. These issues result in uneven chemical composition, internal porosity defects, and flux core detachment, affecting welding quality and joint reliability. These defects reduce the strength, sealing performance, and mechanical properties of the welded joint, increasing the risk of cracks and porosity during welding, thereby reducing the stability and safety of the welded structure and impacting the overall product performance and long-term reliability. The invention proposes a high-performance nickel-based welding wire and its preparation process.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a high-performance nickel-based welding wire preparation process, comprising the following steps: Step 1: Select a specific material formula; Step 2: Pre-treat the raw materials, including screening for metal raw materials such as nickel, chromium, and molybdenum with a purity of over 99.9%, using vacuum drying technology to reduce the moisture content to below 0.01%, and using a combination of mechanical grinding and chemical cleaning to remove impurities such as oil and oxides from the surface of the raw materials, so that the surface finish reaches Ra0.8μm; Step 3: Using vacuum induction melting technology, the melting temperature is controlled at 1500℃-1550℃ in an environment with a vacuum degree of 1×10⁻³Pa, and the melting time is 3-4 hours. During the alloying process, alloying elements are added in batches, and electromagnetic stirring and ultrasonic oscillation are used to promote uniform mixing of alloying elements. Step 4: Use a multi-pass drawing process for forming, with 8-10 drawing passes. The deformation amount of each drawing is controlled at 15%-20%, and the drawing speed is controlled at 0.5m / min-1m / min. Use a special lubricant to ensure that the surface roughness of the welding wire reaches below Ra0.4μm. Step 5: After forming, the welding wire is subjected to stress-relief annealing treatment. It is heated to 700℃-750℃, held for 2-3 hours, and then cooled in the furnace. Then, surface passivation treatment is performed by immersing it in a special passivation solution to form a passivation film. Finally, quality inspections such as chemical composition analysis, mechanical property testing, and metallographic structure observation are carried out.

[0006] The effect achieved by the above components is as follows: the high-performance nickel-based welding wire preparation process using a specific material formula, by clarifying the raw material basis of each subsequent step, lays a key foundation for improving the core indicators such as the mechanical properties and corrosion resistance of the welding wire. Its working principle is that the specific material formula can accurately match the requirements of the raw material composition of subsequent pretreatment, smelting and other processes, ensuring that the parameters of each process can be optimized around the formula target, and ultimately enabling the prepared nickel-based welding wire to have the potential to meet the high-requirement application scenarios.

[0007] Preferably, the rare earth element is one or more combinations of cerium, lanthanum, and yttrium. In the raw material pretreatment, the screened metal raw material is subjected to particle size analysis to ensure that its particle size distribution is within 100-200 mesh, so as to ensure the uniformity of the smelting process.

[0008] The effects achieved by the above components are as follows: In the raw material pretreatment, the screened metal raw materials are subjected to particle size analysis to ensure that their particle size distribution is within 100-200 mesh. At the same time, the high-performance nickel-based welding wire preparation process using one or more combinations of cerium, lanthanum, and yttrium effectively improves the uniformity of the melting process and reduces the problem of alloy composition segregation caused by uneven raw material particle size or improper selection of rare earth elements. Its working principle is that the 100-200 mesh particle size distribution allows the metal raw materials to be heated more evenly and melt at a more consistent speed during melting, while cerium, lanthanum, and yttrium rare earth elements can play a role in purifying the alloy and improving its fluidity. The two work together to ensure the quality stability of the alloy after melting.

[0009] Preferably, during the vacuum induction melting process, the frequency of the electromagnetic stirring is controlled at 50-100Hz, and the power of the ultrasonic oscillation is controlled at 200-300W.

[0010] The effects achieved by the above components are: significantly enhancing the mixing effect of alloying elements and avoiding uneven distribution of alloying elements. The working principle is that the electromagnetic stirring of 50-100Hz can generate a suitable stirring force to drive the flow of molten metal in the melt, and the ultrasonic oscillation of 200-300W can further break up the component agglomerates that may be formed in the melt. The combination of the two allows the alloying elements to fully diffuse and be evenly distributed in the melt, thereby improving the overall performance of the alloy.

[0011] Preferably, the lubricant used in the drawing process is a composite lubricant containing fatty acid esters and graphite, whose lubrication performance index meets the specific lubrication performance standard that the wear rate of the welding wire surface is less than 0.05% under the condition that the drawing force is reduced by 30%-40%.

[0012] The effects achieved by the above components are: not only reducing energy consumption and equipment wear during the drawing process, but also ensuring the surface quality of the welding wire. The working principle is that the composite lubricant composed of fatty acid esters and graphite can form a stable lubricating film between the welding wire and the die, reducing the frictional resistance between the two, thereby reducing the drawing force by 30%-40%. At the same time, the low friction can also reduce the wear of the welding wire surface, making the wear rate less than 0.05%, and ensuring that the surface roughness of the welding wire reaches Ra0.4μm or less.

[0013] Preferably, during the stress-relief annealing process, the heating rate is controlled at 5-10℃ / min and the cooling rate is controlled at 3-5℃ / min.

[0014] The effect achieved by the above components is to effectively eliminate the internal stress generated during the welding wire forming process, and to avoid problems such as cracking and deformation of the welding wire in subsequent use. Its working principle is that the heating rate of 5-10℃ / min allows the internal temperature of the welding wire to rise slowly, so that the internal stress is gradually released, while the cooling rate of 3-5℃ / min can prevent the welding wire from generating new internal stress due to excessive cooling, thus ensuring the stability of the internal structure of the welding wire.

[0015] Preferably, the passivation solution used for the surface passivation treatment is prepared by mixing nitric acid, phosphoric acid and chromic anhydride in a ratio of 5:3:2, and the passivation time is 10-15 minutes.

[0016] The effect achieved by the above-mentioned components is to form a dense and stable passivation film on the surface of the welding wire, which greatly improves the corrosion resistance of the welding wire. The working principle is that after nitric acid, phosphoric acid and chromic anhydride are mixed in a ratio of 5:3:2, they can react chemically with the metal on the surface of the welding wire to generate a dense passivation film within 10-15 minutes. This passivation film can isolate the external corrosive medium from contact with the welding wire substrate, thereby improving the corrosion resistance of the welding wire.

[0017] Preferably, in quality inspection, chemical composition analysis adopts spectral analysis, mechanical property testing includes tensile test, impact test and hardness test, and metallographic structure observation adopts optical microscope and scanning electron microscope. All test indicators must meet the specific quality standards of tensile strength ≥800MPa, yield strength ≥500MPa, impact toughness ≥100J / cm², and uniform and dense metallographic structure without obvious defects.

[0018] The effects achieved by the above components are as follows: strictly controlling the quality of welding wire, ensuring that every welding wire leaving the factory meets the usage requirements. The working principle is that the spectral analysis method can accurately detect whether the chemical composition of the welding wire meets the formula requirements, the tensile test, impact test and hardness test can comprehensively evaluate the mechanical properties of the welding wire, the optical microscope and scanning electron microscope can clearly observe the metallographic structure, and the clear standards of various indicators provide a basis for quality judgment, jointly ensuring the quality of welding wire.

[0019] Preferably, the nickel-based welding wire is based on nickel and is composed of nickel, chromium, molybdenum, titanium, niobium and rare earth elements, with the content of each alloying element being 60%-70% nickel, 15%-20% chromium, 8%-12% molybdenum, 0.5%-1.5% titanium, 0.3%-0.8% niobium and 0.05%-0.15% rare earth elements.

[0020] The aforementioned components achieve the following effects: excellent comprehensive performance, maintaining good stability and reliability even in harsh environments such as high temperature and corrosion. Their working principle involves 60%-70% nickel as the matrix to ensure the basic corrosion resistance and high-temperature stability of the welding wire; 15%-20% chromium to further enhance oxidation and corrosion resistance; 8%-12% molybdenum to enhance high-temperature strength and resistance to intergranular corrosion; 0.5%-1.5% titanium and 0.3%-0.8% niobium to refine grains and improve weld joint toughness; and 0.05%-0.15% rare earth elements to purify the alloy and improve fluidity. This combination of elements in this proportion ensures that the various properties of the welding wire synergistically improve and are comprehensively enhanced.

[0021] Preferably, a high-performance nickel-based welding wire is prepared using a high-performance nickel-based welding wire manufacturing process. The nickel-based welding wire uses nickel as the base material and is composed of nickel, chromium, molybdenum, titanium, niobium, and rare earth elements. The content of each alloying element is as follows: nickel 60%-70%, chromium 15%-20%, molybdenum 8%-12%, titanium 0.5%-1.5%, niobium 0.3%-0.8%, and rare earth elements 0.05%-0.15%. In summary, the beneficial effects of the present invention are as follows: The nickel-based welding wire of this invention achieves significant improvements in mechanical properties and corrosion resistance. The tensile strength is increased by 25%-30%, the yield strength by 20%-25%, and the impact toughness by 30%-35%, effectively enhancing the load-bearing capacity and impact resistance of welded structures. Regarding corrosion resistance, the welding wire exhibits a significantly lower corrosion rate in seawater and acidic / alkaline media than traditional welding wires, extending its service life in harsh environments and meeting the high requirements for welding materials in fields such as chemical engineering and marine engineering.

[0022] In terms of cost optimization, this invention reduces production costs and improves production efficiency by increasing the utilization rate of raw materials and precisely controlling the addition of alloying elements. Employing a multi-pass drawing process and advanced lubrication technology increases drawing speed by 30%-35% and shortens the production cycle by 20%-25%. Furthermore, vacuum induction melting technology and efficient post-processing significantly reduce energy consumption and waste generation, lowering environmental pollution and aligning with green manufacturing principles, thus contributing to energy conservation, emission reduction, and the sustainable use of resources. Detailed Implementation

[0023] Example 1 Material Preparation: Following the material formula described in the invention, prepare metallic raw materials of nickel, chromium, molybdenum, titanium, and niobium, all with a purity of 99.9%. The mass of nickel is 65 kg, chromium 18 kg, molybdenum 10 kg, titanium 1 kg, niobium 0.5 kg, and cerium (0.1 kg) is selected as a rare earth element. Particle size analysis is performed on these metallic raw materials to ensure their particle size distribution falls within a specific range, guaranteeing uniform smelting in subsequent processes. Raw Material Pretreatment: First, the metallic raw materials are finely screened to remove parts with obvious surface defects and impurities. Then, the screened raw materials are placed in a vacuum drying device. Under a vacuum of 1×10⁻³ Pa, the drying temperature is set at 80℃, and the drying time is 5 hours, reducing the moisture content of the raw materials to below 0.01%. Next, mechanical grinding is used to remove the oxide layer and other impurities on the surface of the raw material, followed by cleaning with a chemical cleaning solution. The cleaning solution is made of nitric acid and hydrofluoric acid in a 5:1 ratio to ensure that the surface smoothness of the raw material reaches Ra0.8μm. Melting and Alloying: The pretreated raw materials were placed in a vacuum induction melting furnace and melted under a vacuum of 1×10⁻³ Pa. The melting temperature was slowly increased to 1520℃ at a rate of 8℃ / min for 3.5 hours. During alloying, chromium and molybdenum were added first, and after they were completely dissolved, titanium, niobium, and cerium were added sequentially while electromagnetic stirring and ultrasonic oscillation were activated. The frequency of electromagnetic stirring was controlled at 75Hz, and the power of ultrasonic oscillation was controlled at 250W to ensure thorough and uniform mixing of the alloying elements. Forming Process: The smelted alloy billet is drawn into shape through multiple passes. The number of drawing passes is set to 8, with the deformation per pass controlled at 18%, and the drawing speed at 0.7 m / min. During the drawing process, a composite lubricant containing fatty acid esters and graphite is used. This lubricant meets the specific lubrication performance standard of achieving a surface wear rate of less than 0.05% on the welding wire under a 35% reduction in drawing force. This effectively reduces the drawing force and ensures that the surface roughness of the welding wire reaches below Ra0.4 μm, ultimately yielding a nickel-based welding wire with a diameter of 1.2 mm. Post-processing: The formed welding wire is placed in a heating furnace for stress-relief annealing. The temperature is raised to 720℃ at a heating rate of 8℃ / min, held for 2.5 hours, and then cooled in the furnace at a cooling rate of 4℃ / min. Next, the welding wire is immersed in a passivation solution prepared by nitric acid, phosphoric acid, and chromic anhydride in a 5:3:2 ratio for 12 minutes, forming a dense passivation film on the surface of the welding wire. Comprehensive quality testing is performed on the welding wire. Chemical composition analysis is conducted using spectroscopic analysis. Mechanical property tests include tensile testing, impact testing, and hardness testing. Metallographic observation is performed using optical microscopy and scanning electron microscopy. All test indicators meet the specific quality standards of tensile strength ≥800MPa, yield strength ≥500MPa, impact toughness ≥100J / cm², and uniform, dense metallographic structure without obvious defects. Performance Test Results: The performance of the nickel-based welding wire prepared in Example 1 was tested. Tensile test results showed that its tensile strength reached 820 MPa, a 25% increase compared to nickel-based welding wire prepared by traditional processes; its yield strength reached 540 MPa, a 22% increase. In the impact toughness test, the impact energy reached 110 J, a 30% increase compared to traditional welding wire. In a simulated seawater corrosion environment, after 300 hours of immersion, its corrosion rate was 0.07 mm / a, a 35% reduction compared to traditional welding wire, fully demonstrating the superiority of the preparation process of this invention. Example 2 Material Preparation: In this embodiment, high-purity nickel, chromium, molybdenum, titanium, niobium, and other metal raw materials were prepared, all with a purity of 99.95%. The mass of nickel was 68 kg, chromium 19 kg, molybdenum 11 kg, titanium 1.2 kg, and niobium 0.6 kg. A mixture of lanthanum and yttrium was used as the rare earth element, with masses of 0.08 kg and 0.07 kg respectively, in a ratio of 8:7. Particle size analysis was performed on the raw materials to ensure a particle size distribution within 100-200 mesh. Raw Material Pretreatment: A similar pretreatment method as in Example 1 was used, but the drying temperature was adjusted to 85°C, and the drying time was extended to 6 hours to further reduce the moisture content to 0.008%. The chemical cleaning solution formulation was slightly adjusted, consisting of nitric acid and hydrofluoric acid in a 6:1 ratio to ensure a higher surface finish of Ra0.7 μm for the raw materials. Melting and alloying: In a vacuum induction melting furnace, the vacuum level is increased to 1×10⁻ 4The melting temperature was increased to 1540℃ at a rate of 9℃ / min, and the melting time was extended to 3.8 hours. During alloying, the order and method of adding each alloying element were the same as in Example 1, but the electromagnetic stirring frequency was adjusted to 85Hz and the ultrasonic oscillation power was increased to 280W to further promote the uniform mixing of alloying elements. Forming process: The number of drawing passes was increased to 10, the deformation amount of each drawing was controlled at 20%, and the drawing speed was increased to 0.9m / min. An improved composite lubricant containing fatty acid esters, graphite, and a small amount of nano-ceramic particles was used. Its lubrication performance index met the more stringent specific lubrication performance standard of less than 0.04% of the wire surface wear rate under the condition of a 40% reduction in drawing force, ensuring the smooth progress of the drawing process. The surface roughness of the wire reached Ra 0.3μm or less, and a nickel-based welding wire with a diameter of 1.0mm was finally drawn. Post-processing: During stress-relief annealing, the heating rate was controlled at 9℃ / min, reaching 740℃, and holding for 2.8 hours, followed by furnace cooling at a rate of 4.5℃ / min. The passivation solution used for surface passivation was prepared from nitric acid, phosphoric acid, and chromic anhydride in a 5:3:2 ratio, and the passivation time was adjusted to 14 minutes. The quality inspection method was the same as in Example 1, but the inspection standards were more stringent. All indicators had to meet higher requirements, including tensile strength ≥850MPa, yield strength ≥550MPa, impact toughness ≥110J / cm², and a uniform, dense metallographic structure without obvious defects. Performance Test Results: Performance tests were conducted on the nickel-based welding wire prepared in Example 2, and the results were surprisingly good. Tensile test results showed that the tensile strength reached 880 MPa, a 30% increase compared to nickel-based welding wire prepared by traditional processes; the yield strength reached 590 MPa, a 28% increase. In the impact toughness test, the impact energy reached 120 J, a 35% increase compared to traditional welding wire. Corrosion resistance tests were conducted in a simulated strongly acidic medium (such as a 15% hydrochloric acid solution). After 300 hours of immersion, the corrosion rate was 0.05 mm / a, a 40% reduction compared to traditional welding wire. This further verifies the feasibility and stability of the preparation process of this invention under different conditions, demonstrating its ability to produce high-performance nickel-based welding wires with superior performance.

Claims

1. A process for preparing high-performance nickel-based welding wire, characterized in that, Includes the following steps: Step 1: Select a specific material formula; Step 2: Pre-treat the raw materials, including screening for metal raw materials such as nickel, chromium, and molybdenum with a purity of over 99.9%, using vacuum drying technology to reduce the moisture content to below 0.01%, and using a combination of mechanical grinding and chemical cleaning to remove impurities such as oil and oxides from the surface of the raw materials, so that the surface finish reaches Ra0.8μm; Step 3: Using vacuum induction melting technology, the melting temperature is controlled at 1500℃-1550℃ in an environment with a vacuum degree of 1×10⁻³Pa, and the melting time is 3-4 hours. During the alloying process, alloying elements are added in batches, and electromagnetic stirring and ultrasonic oscillation are used to promote uniform mixing of alloying elements. Step 4: Use a multi-pass drawing process for forming, with 8-10 drawing passes. The deformation amount of each drawing is controlled at 15%-20%, and the drawing speed is controlled at 0.5m / min-1m / min. Use a special lubricant to ensure that the surface roughness of the welding wire reaches below Ra0.4μm. Step 5: After forming, the welding wire is subjected to stress-relief annealing treatment. It is heated to 700℃-750℃, held for 2-3 hours, and then cooled in the furnace. Then, surface passivation treatment is performed by immersing it in a special passivation solution to form a passivation film. Finally, quality inspections such as chemical composition analysis, mechanical property testing, and metallographic structure observation are carried out.

2. The process for preparing a high-performance nickel-based welding wire according to claim 1, characterized in that: The rare earth element is one or more combinations of cerium, lanthanum, and yttrium. In the raw material pretreatment, the screened metal raw material is subjected to particle size analysis to ensure that its particle size distribution is within 100-200 mesh, so as to ensure the uniformity of the smelting process.

3. The process for preparing a high-performance nickel-based welding wire according to claim 1, characterized in that: During the vacuum induction melting process, the frequency of the electromagnetic stirring is controlled at 50-100Hz, and the power of the ultrasonic oscillation is controlled at 200-300W.

4. The process for preparing a high-performance nickel-based welding wire according to claim 1, characterized in that: During the drawing process, the lubricant used is a composite lubricant containing fatty acid esters and graphite. Its lubrication performance index meets the specific lubrication performance standard that the wear rate of the welding wire surface is less than 0.05% under the condition that the drawing force is reduced by 30%-40%.

5. The process for preparing a high-performance nickel-based welding wire according to claim 1, characterized in that: During the stress-relief annealing process, the heating rate is controlled at 5-10℃ / min, and the cooling rate is controlled at 3-5℃ / min.

6. The process for preparing a high-performance nickel-based welding wire according to claim 1, characterized in that: The passivation solution used for the surface passivation treatment is prepared by mixing nitric acid, phosphoric acid and chromic anhydride in a ratio of 5:3:

2.

7. The high-performance nickel-based welding wire preparation process according to claim 6, characterized in that: The passivation time is 10-15 minutes.

8. The process for preparing a high-performance nickel-based welding wire according to claim 1, characterized in that: In quality inspection, chemical composition analysis is performed using spectral analysis, mechanical property testing includes tensile testing, impact testing, and hardness testing, and metallographic observation is performed using optical microscopy and scanning electron microscopy. All test indicators must meet the specific quality standards of tensile strength ≥800MPa, yield strength ≥500MPa, impact toughness ≥100J / cm², and uniform, dense metallographic structure without obvious defects.

9. A high-performance nickel-based welding wire, characterized in that: The high-performance nickel-based welding wire is prepared using any one of claims 1-8. The nickel-based welding wire uses nickel as the base material and is composed of nickel, chromium, molybdenum, titanium, niobium and rare earth elements. The content of each alloying element is 60%-70% nickel, 15%-20% chromium, 8%-12% molybdenum, 0.5%-1.5% titanium, 0.3%-0.8% niobium and 0.05%-0.15% rare earth elements.