Manufacturing method of stainless steel wire with multi-layer composite structure

Abstract

The invention belongs to the technical field of stainless steel wires, and discloses a manufacturing method of a multi-layer composite structure stainless steel wire, the multi-layer composite structure stainless steel wire comprises a central core material, a middle transition layer and an outer wear-resistant layer, the central core material is a high-strength stainless steel wire, the tensile strength of the central core material is not lower than 1200 MPa, the diameter of the central core material is 2 mm, the middle transition layer wraps the periphery of the central core material, and the outer wear-resistant layer wraps the periphery of the middle transition layer. The middle transition layer is a stainless steel alloy layer with specific alloy components, the thickness of the middle transition layer is 0.5 mm, the alloy components in the middle transition layer comprise, by weight, 18%-22% of chromium, 8%-12% of nickel, 2%-4% of molybdenum, 1.5%-2.5% of manganese, 0.5%-1.5% of silicon, 0.3%-0.8% of copper, 0.05%-0.15% of trace niobium and 0.03%-0.08% of vanadium, and the outer abrasion-resistant layer wraps the periphery of the middle transition layer. The stainless steel wire solves the problem that a stainless steel wire with a single structure in the prior art is difficult to meet strict requirements in multiple aspects of high strength, high wear resistance, good corrosion resistance, excellent comprehensive mechanical properties and the like, and is suitable for stainless steel wires.

Description

Technical Field

[0001] The invention relates to the technical field of stainless steel wires, in particular to a method for manufacturing stainless steel wires with a multi-layer composite structure. Background Art

[0002] In the existing stainless steel wire preparation technology, relatively simple and conventional process parameters and material selection are usually adopted, which is significantly different from the manufacturing method of the multi-layer composite structure stainless steel wire of the present invention, resulting in difficulty in achieving the excellent effect achieved by the present invention in product performance.

[0003] For example, in the preparation of the central core material, the prior art generally heats the 304 stainless steel billet to 900°C -1000°C, with a holding time of only 1 - 1.5 hours, and then adopts a wire drawing process with fewer passes, and the compression ratio of the wire drawing die is fixed at about 1.2, the work hardening rate is controlled at 20% - 25%, and it is naturally cooled in the air or simply air-cooled after drawing. This method limits the grain refinement of the core material and the internal structure is not uniform enough, which ultimately results in the tensile strength usually only reaching 500MPa - 700MPa, which is far lower than the tensile strength requirement of not less than 1200MPa for the core material in the present invention, and cannot meet the strength requirements of the stainless steel wire under high stress conditions.

[0004] For the preparation of the intermediate transition layer, the existing technology may adopt ordinary thermal spraying methods, such as arc spraying. Parameters such as gas flow rate and powder feeding amount cannot be accurately controlled, and the spraying distance and spray gun moving speed are also relatively arbitrary. Generally, the hydrogen flow rate is 10L / min-12L / min, the oxygen flow rate is 20L / min-25L / min, the powder feeding amount is 20g / min-25g / min, the spraying distance is 100mm-120mm, and the spray gun moving speed is 200mm / s-300mm / s. No subsequent precise thermal diffusion treatment is performed or the thermal diffusion conditions are roughly controlled. The thermal diffusion temperature is 800℃-900℃, the time is 1-2 hours, and the heating rate and cooling rate are also unstable. The bonding strength between the transition layer and the core material obtained in this way is relatively low, usually between 100MPa-200MPa, and delamination is likely to occur during use, and the stability of the multi-layer structure cannot be guaranteed. This is far from the bonding strength requirement of not less than 300MPa in the present invention, which greatly affects the reliability and service life of the product.

[0005] When preparing the outer wear-resistant layer, the electroplating process will bring about environmental pollution problems, and the coating thickness is uneven, generally 0.1mm - 0.2mm, and the hardness is relatively low, between 400HV - 500HV, and the wear resistance is limited. In the simple coating process, the deposition rate cannot be accurately controlled, at 5μm / h - 8μm / h, the deposition temperature and pressure are unstable, at about 300℃-350℃ and 1Pa - 1.5Pa respectively, the introduced wear-resistant particles are unevenly distributed, the volume ratio is usually 5% - 8%, and there is no effective ultrasonic dispersion treatment, resulting in poor wear resistance and bonding performance of the outer wear-resistant layer with the transition layer, which cannot be compared with the high hardness (600HV), uniform wear resistance and tightly bonded outer wear-resistant layer prepared by precise magnetron sputtering deposition process in the present invention, which seriously limits the service life and performance of stainless steel wire under high friction conditions.

[0006] In summary, the prior art has many deficiencies in the process parameters and methods of stainless steel wire preparation. Compared with the present invention, there is an obvious gap in product strength, bonding strength, wear resistance, and stability and reliability of comprehensive performance, and it cannot meet the growing demand of modern industry for high-performance stainless steel wire. Therefore, the manufacturing method of the multi-layer composite structure stainless steel wire of the present invention has significant innovation and practical value. Summary of the invention

[0007] The present invention aims to provide a method for manufacturing a multi-layer composite structure stainless steel wire to solve the problem that the existing single structure stainless steel wire can hardly meet the stringent requirements in terms of high strength, high wear resistance, good corrosion resistance and excellent comprehensive mechanical properties.

[0008] In order to achieve the above object, the present invention provides the following technical solutions: The technical solution provided by the present invention is: a method for manufacturing a multi-layer composite structure stainless steel wire, comprising a central core material, an intermediate transition layer and an outer wear-resistant layer; The manufacturing method of the multi-layer composite structure stainless steel wire is as follows: S1: Preparation of the center core material: Select a stainless steel billet that meets the 304 stainless steel standard, heat it to 1100℃-1200℃, and keep it warm for 2-3 hours to make the billet homogenized; A multi-pass wire drawing process is adopted, and online tension detection and adjustment are performed after each wire drawing. The initial compression ratio of the wire drawing die is 1.3, and the wire drawing is performed in a manner of increasing by 0.1 each time until the stainless steel billet is processed into a high-strength stainless steel wire with a diameter of 2mm. The work hardening rate is controlled between 30% and 40% during the wire drawing process; The drawn stainless steel wire is subjected to annealing heat treatment in a protective atmosphere of argon, the annealing temperature is 800°C-900°C, the annealing time is 2 hours, and the cooling rate is controlled at 50°C / h-80°C / h; S2: Coating and thermal diffusion of the intermediate transition layer: The alloy powder is accurately prepared according to the alloy composition ratio of the intermediate transition layer, and the intermediate transition layer alloy powder is sprayed on the periphery of the central core material by supersonic flame spraying. During supersonic flame spraying, hydrogen and oxygen are used as fuel gases, with a hydrogen flow rate of 15L / min-20L / min, an oxygen flow rate of 30L / min-40L / min, a powder feeding amount of 30g / min-40g / min, a spraying distance of 150mm-200mm, and a spray gun moving speed of 300mm / s-500mm / s, so that the spraying thickness reaches 0.5mm; The sprayed composite wire is placed in a vacuum thermal diffusion furnace and subjected to thermal diffusion treatment in an environment with a vacuum degree better than 5×10⁻³Pa. The thermal diffusion temperature is 1000℃-1100℃, the thermal diffusion time is 3 hours, the heating rate is 10℃ / min-15℃ / min, and the cooling rate is 8℃ / min-12℃ / min, so that the intermediate transition layer and the central core material are firmly bonded. S3: The outer wear-resistant layer is deposited on the periphery of the intermediate transition layer by magnetron sputtering deposition process. The sputtering target material is an alloy target material matching the alloy composition of the outer wear-resistant layer. During the deposition process, the deposition rate is controlled to be 10μm / h-15μm / h, the deposition temperature is 400℃-500℃, and the deposition pressure is 2Pa-3Pa; During the deposition process, tungsten carbide particles are simultaneously introduced through a powder introduction device. Before introduction, the tungsten carbide particles are subjected to ultrasonic dispersion treatment, wherein the dispersion medium of the tungsten carbide particles is anhydrous ethanol, the ultrasonic frequency is 20kHz-30kHz, and the ultrasonic time is 30min-60min, so that the tungsten carbide particles are evenly dispersed in the outer wear-resistant layer, and finally an outer wear-resistant layer with a thickness of 0.3mm is formed; S4: The prepared stainless steel wire is subjected to a final heat treatment under a nitrogen protective atmosphere, with a heat treatment temperature of 500°C-600°C, a heat treatment time of 1 hour, a heating rate of 12°C / min-18°C / min, and a furnace cooling method to improve the overall performance of the steel wire. Finally, a prepared multi-layer composite structure stainless steel wire is obtained. Furthermore, in S2, the thermal spraying process adopts supersonic flame spraying, the gas flow rate during spraying is 15L / min-20L / min, and the powder feeding amount is 30g / min-40g / min.

[0009] Furthermore, in S3, the physical vapor deposition process is magnetron sputtering deposition, the sputtering power is 1000W-1500W, and the distance between the target and the steel wire is 80mm.

[0010] Furthermore, an intermediate transition layer is wrapped around the outer periphery of the central core material. The intermediate transition layer is a stainless steel alloy layer with a specific alloy composition. The thickness of the intermediate transition layer is 0.5 mm. The alloy composition ratio in the intermediate transition layer is: chromium 18%-22%, nickel 8%-12%, molybdenum 2%-4%, manganese 1.5%-2.5%, silicon 0.5%-1.5%, copper 0.3%-0.8% and trace amounts of niobium 0.05%-0.15% and vanadium 0.03%-0.08%, and the remainder is Fe and unavoidable impurities. The intermediate transition layer and the central core material are bonded by thermal diffusion, and the bonding strength is not less than 300 MPa.

[0011] Furthermore, the central core material is a high-strength stainless steel wire with a tensile strength of not less than 1200 MPa and a diameter of 2 mm.

[0012] Furthermore, the outer wear-resistant layer is coated on the outer periphery of the middle transition layer. The outer wear-resistant layer is a stainless steel wear-resistant alloy layer that has undergone special heat treatment. The thickness of the outer wear-resistant layer and the hardness of the outer wear-resistant layer are 0.3 mm and 600 HV, respectively. The outer wear-resistant layer and the middle transition layer are combined through a physical vapor deposition process to form a dense bonding interface, and the element diffusion depth at the bonding interface is 0.05 mm.

[0013] Furthermore, the stainless steel material of the central core material is 304 stainless steel.

[0014] Furthermore, the stainless steel alloy composition of the intermediate transition layer also includes 0.5%-1.5% titanium, and the titanium element forms a titanium-rich diffusion layer at the interface between the intermediate transition layer and the central core material, and the thickness of the titanium-rich diffusion layer is 0.02 mm.

[0015] Furthermore, tungsten carbide particles are added to the stainless steel wear-resistant alloy of the outer wear-resistant layer, the volume ratio of the tungsten carbide particles is 10%, and the tungsten carbide particles are evenly distributed in the wear-resistant layer.

[0016] The beneficial effects of this technical solution are: (1) The multi-layer composite stainless steel wire of the present invention combines the high strength of the central core material, the good bonding performance of the intermediate transition layer, and the high wear resistance of the outer wear-resistant layer through a unique three-layer structural design. The stainless steel wire has a tensile strength of not less than 1200MPa, which can withstand loads under high stress environments, and has excellent corrosion resistance (thanks to the alloy composition of the 304 stainless steel core material and the intermediate transition layer). At the same time, it also has good wear resistance (the outer wear-resistant layer has a hardness of 600HV and contains uniformly distributed tungsten carbide particles), which can meet the stringent requirements for the comprehensive performance of stainless steel wire in high-precision fields such as aerospace, marine engineering, and automobile engines, and effectively solves the problem that existing stainless steel wire cannot meet multiple high-performance requirements at the same time.

[0017] (2) The intermediate transition layer and the central core material form a strong bond through a precisely controlled thermal diffusion process, and the bonding strength is not less than 300MPa. The outer wear-resistant layer and the intermediate transition layer form a dense bonding interface through a precise magnetron sputtering deposition process, and the element diffusion depth at the bonding interface is 0.05mm. This high-strength and dense interlayer bonding structure effectively prevents the delamination of each layer during processing and use. Whether it is under the tensile force in the wire drawing process or under the complex external forces of bending, torsion, and friction in actual use, it can maintain the integrity and stability of the structure, greatly improving the reliability and service life of the product, reducing the safety hazards and maintenance costs caused by structural failure, and solving the problem of unstable bonding between layers of composite structure stainless steel wire.

[0018] (3) Each link in the entire preparation method, from the preparation process parameters of the central core material (such as heating temperature, holding time, drawing compression ratio, work hardening rate, annealing conditions), to the coating and thermal diffusion process parameters of the intermediate transition layer (gas flow, powder feeding amount, spraying distance, thermal diffusion temperature, time, rate), to the deposition process parameters of the outer wear-resistant layer (deposition rate, temperature, pressure, tungsten carbide particle processing parameters) and the final heat treatment conditions (temperature, time, heating rate, cooling method), are all precisely controlled and optimized, so that the various properties of the stainless steel wire (strength, hardness, wear resistance, corrosion resistance, bonding strength) can be precisely adjusted and stably reproduced. This is not only conducive to large-scale standardized production, improving production efficiency and reducing production costs, but also can flexibly adjust process parameters according to the special needs of different customers to customize stainless steel wire products with specific properties to meet diverse market needs, solving the problem of difficult precise control of stainless steel wire performance and difficulty in customized production in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A comparison table of material composition and performance parameters of different embodiments of a method for manufacturing a multi-layer composite structure stainless steel wire proposed by the present invention; Figure 2 This is a performance comparison table of different embodiments of a method for manufacturing a multi-layer composite structure stainless steel wire proposed by the present invention under simulated working conditions; Figure 3 A comparative test data table of the corrosion resistance of each embodiment of the method for manufacturing a multi-layer composite structure stainless steel wire proposed by the present invention compared with that of a traditional stainless steel wire; Figure 4 A table showing the high temperature performance comparison test data of various embodiments of a method for manufacturing a multi-layer composite structure stainless steel wire proposed by the present invention compared with traditional stainless steel wire; Figure 5This is a comparative test data table of fatigue performance of various embodiments of a method for manufacturing a multi-layer composite structure stainless steel wire proposed by the present invention compared with traditional stainless steel wire; Figure 6 This is a comparative test data table of low temperature toughness of each embodiment of a method for manufacturing a multi-layer composite structure stainless steel wire proposed by the present invention compared with that of a traditional stainless steel wire; Figure 7 This is a table of comprehensive comparative test data on hardness and wear resistance of various embodiments of a method for manufacturing a multi-layer composite structure stainless steel wire proposed in the present invention compared with traditional stainless steel wire. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The specific implementation process is as follows: Embodiment 1: See also Figure 1-7 The present invention provides a technical solution: a method for manufacturing a multi-layer composite structure stainless steel wire, comprising the following steps: S1: Preparation of the center core material: Select a stainless steel billet that meets the 304 stainless steel standard, heat it to 1100℃-1200℃, and keep it warm for 2-3 hours to homogenize the billet and eliminate possible component segregation defects; A multi-pass wire drawing process is adopted. After each wire drawing, an advanced online tension detection and adjustment device is used to ensure the stability of the wire tension during the wire drawing process to avoid uneven wire diameter or crack defects caused by tension fluctuations. The initial compression ratio of the wire drawing die is 1.3, and the wire drawing is performed in an increment of 0.1 each time. Through the gradually decreasing compression ratio, multiple drawing passes are performed to effectively control the degree of work hardening until the stainless steel billet is processed into a high-strength stainless steel wire with a diameter of 2mm. The work hardening rate is controlled between 30% and 40% during the wire drawing process; The drawn stainless steel wire is subjected to annealing heat treatment under a protective atmosphere of argon, the annealing temperature is 800℃-900℃, the annealing time is 2 hours, and the cooling rate is controlled at 50℃ / h-80℃ / h. The annealing treatment can eliminate the work hardening produced during the wire drawing process, restore the plasticity of the steel wire, and refine the grains, thereby improving the comprehensive mechanical properties of the steel wire. S2: Coating and thermal diffusion of the intermediate transition layer: The alloy powder is accurately prepared according to the alloy composition ratio of the intermediate transition layer, and the intermediate transition layer alloy powder is sprayed on the periphery of the central core material by supersonic flame spraying. The gas flow rate during supersonic flame spraying is 15L / min-20L / min, and the powder feeding amount is 30g / min-40g / min. During supersonic flame spraying, hydrogen and oxygen are used as fuel gases, with a hydrogen flow rate of 15L / min-20L / min, an oxygen flow rate of 30L / min-40L / min, a powder feeding amount of 30g / min-40g / min, a spraying distance of 150mm-200mm, and a spray gun moving speed of 300mm / s-500mm / s, so that the spraying thickness reaches 0.5mm; The sprayed composite wire is placed in a vacuum thermal diffusion furnace and subjected to thermal diffusion treatment in an environment with a vacuum degree better than 5×10⁻³Pa. The thermal diffusion temperature is 1000℃-1100℃, the thermal diffusion time is 3 hours, the heating rate is 10℃ / min-15℃ / min, and the cooling rate is 8℃ / min-12℃ / min. During the thermal diffusion process, the alloy elements of the intermediate transition layer and the elements of the central core material diffuse with each other to form a strong metallurgical bond, ensuring good bonding strength and cooperative working ability between the two layers, so that the intermediate transition layer and the central core material form a strong bond; S3: The outer wear-resistant layer is deposited on the periphery of the intermediate transition layer by magnetron sputtering deposition process. The sputtering target is an alloy target that matches the alloy composition of the outer wear-resistant layer. The sputtering power is 1000W-1500W, the distance between the target and the steel wire is 80mm, and the deposition rate is controlled to be 10μm / h-15μm / h during the deposition process. The deposition temperature is 400℃-500℃ and the deposition pressure is 2Pa-3Pa; During the deposition process, tungsten carbide particles are simultaneously introduced through a powder introduction device. Before the introduction, the tungsten carbide particles are subjected to ultrasonic dispersion treatment in anhydrous ethanol, with an ultrasonic frequency of 20kHz-30kHz and an ultrasonic time of 30min-60min. The treated tungsten carbide particles can be evenly dispersed in the outer wear-resistant layer, thereby effectively improving the wear resistance of the stainless steel wire, and finally forming an outer wear-resistant layer with a thickness of 0.3mm; S4: The prepared stainless steel wire is subjected to a final heat treatment under a nitrogen protective atmosphere, the heat treatment temperature is 500°C-600°C, the heat treatment time is 1 hour, the heating rate is 12°C / min-18°C / min, and the cooling adopts a furnace cooling method. The final heat treatment can further optimize the organizational structure of the entire composite steel wire, eliminate the internal residual stress, and improve its comprehensive performance, making it more stable and reliable in the subsequent use process, so as to improve the comprehensive performance of the overall steel wire, and finally obtain the prepared multi-layer composite structure stainless steel wire; According to the above manufacturing method, a batch of high-quality 304 stainless steel billets are selected, first heated to 1150℃, kept warm for 2.5 hours, and then subjected to multiple drawing passes, the compression ratio of the first drawing die is 1.4, the second is 1.5, the third is 1.6... and so on. During the drawing process, the work hardening rate is closely monitored to keep it at about 33%, and finally a central core stainless steel wire with a diameter of 2mm is obtained. The wire is subjected to annealing heat treatment, the annealing temperature is set to 850℃, the annealing time is 2 hours, and the cooling rate is controlled at 60℃ / h. Then, an intermediate transition layer alloy powder is prepared, in which the chromium content is 20%, the nickel content is 10%, the molybdenum content is 3%, the manganese content is 2%, the silicon content is 1%, the copper content is 0.5%, the niobium content is 0.1%, the vanadium content is 0.05%, and the titanium content is 1%. The supersonic flame spraying process is adopted, the hydrogen flow rate is 18L / min, the oxygen flow rate is 35L / min, the powder feeding amount is 35g / min, the spraying distance is 180mm, and the spray gun is moved The moving speed is 400mm / s, and a 0.5mm thick intermediate transition layer is sprayed on the periphery of the central core material. Then the composite wire is placed in a vacuum thermal diffusion furnace. In an environment with a vacuum degree of 3×10⁻³Pa, the temperature is increased to 1050℃ at a heating rate of 12℃ / min, and thermal diffusion is performed for 3 hours. Then, the temperature is cooled at a cooling rate of 10℃ / min, and the magnetron sputtering deposition process is used. The sputtering power is 1200W, the distance between the target and the steel wire is 80mm, and the deposition rate is 12μm / h. The deposition temperature is 450°C, the deposition pressure is 2.5Pa, an outer wear-resistant layer alloy is deposited on the periphery of the intermediate transition layer, and tungsten carbide particles that have been ultrasonically dispersed (ultrasonic frequency 25kHz, ultrasonic time 45min) are simultaneously introduced to form a 0.3mm thick outer wear-resistant layer. Finally, the prepared multi-layer composite structure stainless steel wire is subjected to final heat treatment under nitrogen protection, the heat treatment temperature is 550°C, the heat treatment time is 1 hour, the heating rate is 15°C / min, and it is cooled with the furnace; Table 1 records in detail the key process parameters and corresponding test data in each manufacturing step from the preparation of the central core material to the final heat treatment of Example 1. In the central core material heating stage, the specific heating temperature of 1150°C and the holding time of 2.5 hours are to make the blank uniform, laying a good foundation for the subsequent wire drawing process. During the wire drawing process, the precisely controlled multi-pass compression ratio and work hardening rate ensure that the central core material has appropriate strength and plasticity while reaching the target diameter of 2 mm. The parameter settings of the annealing process (temperature 850℃, time 2 hours, cooling rate 60℃ / h) are aimed at eliminating the work hardening caused by wire drawing and refining the grains. From the test data "significant grain refinement effect and good plastic recovery", it can be seen that the process has achieved the expected effect. In the intermediate transition layer spraying process, the determination of various parameters (hydrogen flow rate, oxygen flow rate, powder feeding amount) is to form a transition layer with uniform thickness (0.5mm) and good quality on the periphery of the central core material. The vacuum degree, heating and cooling rate, and processing temperature and time parameters of the thermal diffusion process ensure the formation of a strong bonding interface between the intermediate transition layer and the central core material, uniform element diffusion, and the deposition process of the outer wear-resistant layer. In the process, the sputtering power, deposition rate, temperature, pressure and ultrasonic treatment parameters of tungsten carbide particles work together to make the thickness of the outer wear-resistant layer reach 0.3mm and the tungsten carbide particles are evenly distributed. The parameters of the final heat treatment further optimize the overall structure, eliminate residual stress, and improve the overall performance. The test data shows that the tensile strength of the central core material of the multi-layer composite structure stainless steel wire is 1250MPa, the bonding strength between the middle transition layer and the central core material is 320MPa, and the hardness of the outer wear-resistant layer is 610HV. It also shows excellent performance under simulated high wear and high stress conditions. The wear amount is reduced by about 60% compared with traditional stainless steel wire, and the tensile strength is increased by about 30%.

[0022] Table 1 Key process parameters and test data of a manufacturing process of embodiment 1 Embodiment 2: See also Figure 1-7 The present invention provides a technical solution: according to steps S1-S4 in Example 1, the same 304 stainless steel blank as in Example 1 is selected, heated to 1100°C, and wire drawn after keeping warm for 3 hours; the compression ratios of the wire drawing dies are 1.3, 1.45, and 1.6 respectively, and the work hardening rate is controlled at about 35% to obtain a central core steel wire with a diameter of 2 mm, the annealing heat treatment temperature is 820°C, and the cooling rate is 70°C / h; The intermediate transition layer alloy powder contains 19% chromium, 9% nickel, 2.5% molybdenum, 1.8% manganese, 0.8% silicon, 0.4% copper, 0.08% niobium, 0.04% vanadium and 0.8% titanium. During supersonic flame spraying, the hydrogen flow rate is 16L / min, the oxygen flow rate is 32L / min, the powder feeding amount is 32g / min, the spraying distance is 160mm, the spray gun moving speed is 350mm / s, the vacuum degree during vacuum thermal diffusion treatment is 4×10⁻³Pa, the heating rate is 11℃ / min to 1020℃, and the cooling rate is 9℃ / min after 3 hours of thermal diffusion; The outer wear-resistant layer was deposited by magnetron sputtering, with a sputtering power of 1100W, a deposition rate of 11μm / h, a deposition temperature of 420℃, a deposition pressure of 2.2Pa, and the introduction of ultrasonic dispersion (ultrasonic frequency of 22kHz, ultrasonic time of 35min) of tungsten carbide particles; the final heat treatment temperature was 520℃, and the heating rate was 13℃ / min; Table 2 shows the process parameters and test results of each step in the manufacturing process for Example 2. The central core material heating temperature (1100°C) and the holding time (3 hours) are slightly different from those in Example 1, which affects the initial organizational state of the blank. In the subsequent wire drawing process, different compression ratios (1.3 for the first pass and 1.45 for the second pass) and work hardening rates (35%) are controlled to obtain a central core material steel wire with a diameter of 2 mm. The annealing process parameters (temperature 820°C, cooling rate 70°C / h) are also adjusted accordingly. It can be seen from the test data that the uniformity of the organization and the plasticity recovery are better. The intermediate transition layer spraying and thermal expansion Changes in the parameters of the dispersion process, such as hydrogen flow rate of 16L / min and oxygen flow rate of 32L / min, lead to differences in the final bonding interface and element diffusion. The test data can be used to analyze the influence of these parameters on the quality of the transition layer. The parameters of the outer wear-resistant layer deposition and the final heat treatment also have their own characteristics, which ultimately makes the stainless steel wire of this embodiment show different characteristics from those of Example 1 in performance. The tensile strength of the central core material of the stainless steel wire is 1220MPa, the bonding strength is 310MPa, and the hardness of the outer wear-resistant layer is 605HV. In actual tests, the wear amount is reduced by about 55% compared with traditional stainless steel wire, and the tensile strength is increased by about 25%.

[0023] Table 2 Key process parameters and test data of the manufacturing process in Example 2 Embodiment three: See also Figure 1-7The present invention provides a technical solution: according to steps S1-S4 in Example 1, the same 304 stainless steel blank as in Example 1 is selected as the starting material, heated to 1200°C and kept for 2 hours before drawing, the drawing compression ratio is set to a series of values ​​of 1.5, 1.6, and 1.7, the work hardening rate is controlled at 30%-32%, and a center core steel wire with a diameter of 2 mm is made, the annealing temperature is 880°C, the cooling rate is 55°C / h, the intermediate transition layer alloy composition is: 21% chromium, 11% nickel, 3.5% molybdenum, 2.2% manganese, 1.2% silicon, 0.6% copper, 0.12% niobium, 0.06% vanadium, and 1.2% titanium, and the supersonic flame spraying parameters are Hydrogen flow rate is 19L / min, oxygen flow rate is 38L / min, powder feeding amount is 38g / min, spraying distance is 190mm, and spray gun moving speed is 450mm / s; vacuum thermal diffusion conditions are vacuum degree 2×10⁻³Pa, temperature rise 14℃ / min to 1080℃, temperature drop 11℃ / min after thermal diffusion for 3 hours, magnetron sputtering deposition of outer wear-resistant layer, sputtering power 1400W, deposition rate 14μm / h, deposition temperature 480℃, deposition pressure 2.8Pa, tungsten carbide particles ultrasonic dispersion (ultrasonic frequency 28kHz, ultrasonic time 50min), final heat treatment temperature 580℃, heating rate 17℃ / min; Table 3 shows the manufacturing process parameters and test data details of Example 3. The central core material heating stage adopts a higher temperature of 1200°C and a holding time of 2 hours, which is slightly different from Example 1 and Example 2. It has a unique effect on the homogenization of the blank. In the wire drawing process, the target central core material is obtained by a specific compression ratio (1.5, 1.6, 1.7) and a work hardening rate (30-32%). The annealing process (temperature 880°C, cooling rate 55°C / h) further optimizes its organizational structure. The setting of the intermediate transition layer spraying parameters (hydrogen flow rate 19L / min) and thermal diffusion parameters (vacuum degree 2×10⁻³Pa) makes the transition layer and the central core material closely combined and the elements diffuse well. The deposition parameters of the outer wear-resistant layer (sputtering power 1400W) ensure the high-quality formation of the wear-resistant layer, and the final heat treatment parameters (temperature 580℃) improve the overall performance. The test data show the results of the synergistic effect of various process links, such as the excellent performance indicators of the central core material tensile strength of 1280MPa and the bonding strength of 330MPa.

[0024] Table 3 Key process parameters and test data of the manufacturing process of Example 3 Embodiment 4: See also Figure 1-7The present invention provides a technical solution: a method for manufacturing a multi-layer composite structure stainless steel wire, comprising a central core material, an intermediate transition layer and an outer wear-resistant layer, wherein the central core material is a high-strength stainless steel wire, the stainless steel material of the central core material is 304 stainless steel, the tensile strength of which is not less than 1200MPa, the diameter of which is 2mm, and the central core material serves as the core support part of the entire composite steel wire and bears the main tensile load, the intermediate transition layer is wrapped around the outer periphery of the central core material, the intermediate transition layer is a stainless steel alloy layer with a specific alloy composition, the thickness of which is 0.5mm, and the alloy composition ratio in the intermediate transition layer is: chromium 18%-22%, nickel 8%-12%, molybdenum 2%-4%, manganese 1.5%-2.5%, silicon 0.5%-1.5%, copper 0.3%-0.8% and trace amounts of niobium 0.05%-0.15% and vanadium 0.03%-0.08%, the remainder being Fe and unavoidable impurities, and the intermediate transition layer and the central core material are bonded by thermal diffusion, and the bonding strength thereof is not less than 3 00MPa, the stainless steel alloy composition of the intermediate transition layer also includes titanium 0.5%-1.5%, and the titanium element forms a titanium-rich diffusion layer at the interface between the intermediate transition layer and the central core material, and the thickness of the titanium-rich diffusion layer is 0.02mm, the chromium element can improve the corrosion resistance of stainless steel, nickel can enhance its toughness and corrosion resistance, molybdenum helps to improve strength and corrosion resistance, manganese and silicon elements can improve the processing performance of the alloy, trace amounts of niobium and vanadium can refine the grains, and further improve the comprehensive performance of the material, the intermediate transition layer and the central core material are bonded by thermal diffusion, and the bonding strength is not less than 300MPa. This bonding method can effectively transfer stress, so that the two layers work together to avoid delamination defects. In addition, the stainless steel alloy composition of the intermediate transition layer also includes titanium 0.5%-1.5%, and the titanium element forms a titanium-rich diffusion layer at the interface between the intermediate transition layer and the central core material, and the thickness of the titanium-rich diffusion layer is 0.02mm. The titanium-rich layer can further improve the stability and bonding strength of the bonding interface; The outer wear-resistant layer is coated on the periphery of the middle transition layer. The outer wear-resistant layer is a stainless steel wear-resistant alloy layer that has undergone special heat treatment. Its thickness is 0.3mm and its hardness is 600HV. The outer wear-resistant layer and the middle transition layer are combined through a physical vapor deposition process to form a dense bonding interface. The element diffusion depth at the bonding interface is 0.05mm. This tight combination ensures that the outer wear-resistant layer will not fall off during use. Tungsten carbide particles are added to the stainless steel wear-resistant alloy of the outer wear-resistant layer. The volume ratio of tungsten carbide particles is 10%, and the tungsten carbide particles are evenly distributed in the wear-resistant layer. Tungsten carbide has extremely high hardness and wear resistance, which can significantly improve the wear resistance of stainless steel wire, so that it can still maintain good performance in a high wear environment. Figure 1The material composition and performance parameter comparison table of different embodiments mainly presents the key material composition data and important performance parameters of the multi-layer composite structure stainless steel wire in the three embodiments. By comparing the tensile strength of the central core material, the bonding strength of the intermediate transition layer and the hardness of the outer wear-resistant layer in different embodiments, the differences in mechanical properties of the embodiments can be intuitively seen. For example, the tensile strength of the central core material in Embodiment 3 is the highest, reaching 1280MPa. This is due to the comprehensive influence of the heating temperature, wire drawing process parameters and annealing treatment links in the preparation process of the central core material, which makes the organizational structure of the central core material more optimized. In terms of material composition, the chromium and nickel content of the intermediate transition layer varies in different embodiments. These changes will affect the corrosion resistance, strength and toughness of the transition layer, and then produce a synergistic effect on the performance of the entire composite steel wire. The volume fraction of tungsten carbide in the outer wear-resistant layer remains consistent, indicating that in the design of the present invention, this volume fraction is determined as a key factor in improving wear resistance, and this ratio is maintained under different process conditions to ensure the stable improvement of wear resistance. Figure 2 The performance of the stainless steel wires of the three embodiments under simulated actual working conditions was compared. The relative reduction ratio of wear reflects the improvement effect of the outer wear-resistant layer and the entire composite structure on the wear resistance. The wear of embodiment 3 is reduced by about 65% compared with the traditional stainless steel wire, which is the best performance. This is due to its comprehensive advantages in material composition and manufacturing process. The relative increase ratio of tensile strength reflects the enhancement effect of the central core material and the synergistic effect between the layers on the overall strength. The tensile strength of embodiment 3 is relatively increased by about 35%, indicating that the processing of the central core material preparation and the combination process of each layer enables the role of each layer to be more effectively exerted when bearing tensile loads, thereby significantly improving the overall tensile strength. In comparison, the improvement of various performances of embodiment 2 is slightly lower than that of embodiments 1 and 3. This is due to the different performances caused by the comprehensive differences in its process parameters and material composition, but overall they all exceed the performance of traditional stainless steel wires. See also Figure 3 Corrosion resistance comparison test data table Salt spray test (rust point appearance time, h): 1. Separately cut conventional stainless steel wires of the same specifications (length, diameter) and multi-layer composite stainless steel wire samples of each embodiment, with at least 3 samples in each group to ensure the reliability of the data; 2. Use sandpaper to grind the sample surface to the same roughness, then clean and dry it with anhydrous ethanol to remove surface oil and impurities; 3. Prepare the salt spray test chamber, configure the sodium chloride solution according to the standard, set the concentration to 5% (mass fraction), and adjust the temperature in the test chamber to 35°C and the relative humidity to 95%; 4. Place the treated samples in different locations in the salt spray test chamber to ensure that the samples do not touch each other and are in an area where the salt spray is evenly distributed; 5. Take out the samples every 24 hours and observe whether there are rust spots on the surface of the samples under a microscope, and record the time when the rust spots appear. For each group of samples, the time when the first rust spot appears is taken as the test result of the group; According to the experimental results, the conventional stainless steel wire has rust spots after 200 hours, indicating that its corrosion resistance is relatively weak in such a harsh environment, while the multi-layer composite stainless steel wire of Example 1 has rust spots after 500 hours, Example 2 after 450 hours, and Example 3 after 600 hours. This is because the reasonable matching of the materials of each layer and the interface bonding characteristics in the multi-layer composite structure effectively prevent the corrosion of the chloride ion corrosive medium, especially the alloy elements (such as chromium and nickel) in the intermediate transition layer and the outer wear-resistant layer form a more dense and stable passivation film on the surface, which delays the corrosion process; Weight loss rate after immersion in acidic solution (%, immersion for 72 hours): 1. Accurately weigh the same mass of conventional stainless steel wire and stainless steel wire samples of each embodiment, which may be in the shape of wire or sheet, and the number of samples in each group shall be no less than 3; 2. Prepare an acidic immersion solution with 5% (volume fraction) sulfuric acid solution. The volume of the solution should be sufficient to completely immerse the sample and place it in a constant temperature water bath and adjust the temperature to 25°C. 3. Hang or place the samples separately in the acid solution, making sure that the samples are completely immersed and do not touch the container wall; 4. After soaking for 72 hours, take out the sample, rinse it with plenty of water, then clean it with anhydrous ethanol and dry it to constant weight; 5. According to the formula: weight loss rate = [(initial mass - final mass) / initial mass] × 100%, calculate the weight loss rate of each group of samples and take the average value as the test result; According to the experimental results, when the stainless steel wire is immersed in an acidic solution, a chemical reaction will occur, resulting in material quality loss. The weight loss rate of the conventional stainless steel wire after 72 hours of immersion is 0.5%, indicating that it has a certain degree of corrosion in an acidic environment. The weight loss rate of Example 1 is only 0.15%, that of Example 2 is 0.2%, and that of Example 3 is 0.1%. This is because the various layers of the composite steel wire have better blocking and resistance to acidic media, the special alloy composition of the intermediate transition layer can neutralize the erosion of acidic substances to a certain extent, and the outer wear-resistant layer also plays a protective role, reducing the contact opportunity between the acidic solution and the central core material, thereby reducing the overall weight loss rate, reflecting excellent acid corrosion resistance. Weight loss rate after immersion in alkaline solution (%, immersion for 72 hours): 1. Similar to the acid solution immersion test, prepare samples of the same quality and specifications, with no less than 3 samples in each group; 2. Prepare an alkaline soaking solution, such as 10% (mass fraction) sodium hydroxide solution, place it in a constant temperature water bath and adjust the temperature to 25°C; 3. Soak the sample in alkaline solution for 72 hours. The operation process is the same as that of acid solution immersion, including the cleaning and drying steps after immersion. 4. Calculate the weight loss rate of each group of samples in alkaline solution according to the weight loss rate calculation formula, and take the average value as the final test data; According to the experimental results, in the alkaline solution immersion test, the weight loss rate of the conventional stainless steel wire was 0.4%; the weight loss rate of the multi-layer composite stainless steel wire of Example 1 was 0.12%, that of Example 2 was 0.18%, and that of Example 3 was 0.08%; this indicates that the multi-layer composite structure also exhibits good corrosion resistance in an alkaline environment, and the synergistic effect between the layers can resist the corrosion of the stainless steel wire by alkaline substances, which may be because certain elements (such as silicon) in the intermediate transition layer and the outer wear-resistant layer form stable compounds in an alkaline environment, inhibiting the corrosion reaction; See also Figure 4 High temperature performance comparison test data table High temperature tensile strength (600°C, MPa): 1. Process and prepare standard tensile specimens. The shape and size of the specimens of conventional stainless steel wire and the stainless steel wire of each embodiment shall be strictly in accordance with the relevant standards (GB / T228.1-2010). Each group of specimens shall be at least 3; 2. Preheat the high temperature tensile testing machine to 600°C and stabilize the temperature to ensure that the temperature fluctuation is within ±5°C during the test; 3. Install the sample on the fixture of the high temperature tensile testing machine, ensuring that the clamp is firm and the axis of the sample is consistent with the direction of tension; 4. Apply tension to the sample at a constant tensile rate (0.5 mm / min) and record the tension and displacement data until the sample breaks; 5. Calculate the tensile strength of each sample according to the stress-strain curve, and take the average value as the high-temperature tensile strength test result of this group of samples at 600°C; According to the experimental results, the mechanical properties of the material will change under high temperature environment (600°C). The high temperature tensile strength of the traditional stainless steel wire is 400MPa, while the multilayer composite stainless steel wire of Example 1 reaches 650MPa, Example 2 is 600MPa, and Example 3 is 700MPa. This is due to the interaction of the materials of each layer in the multilayer composite structure at high temperature. The central core material provides a certain basic strength, the alloy elements of the intermediate transition layer can maintain good organizational structure stability at high temperature, and the strong combination with the central core material enables the stress to be effectively transmitted. The outer wear-resistant layer also plays a certain strengthening role on the overall structure, and together improves the ability to withstand tensile loads at high temperatures. High temperature oxidation resistance (weight gain rate, mg / cm²・h, 800°C, 100h): 1. Prepare conventional stainless steel wire and stainless steel wire samples of each embodiment with the same surface area, which may be in the form of sheets or wires, and the number of samples in each group shall be no less than 3; 2. After cleaning and drying the sample, accurately weigh its initial mass; 3. Preheat the high temperature oxidation test furnace to 800°C and keep the temperature stable within a fluctuation range of ±3°C; 4. Place the samples on the ceramic bracket in the high temperature oxidation test furnace, ensuring that the samples do not touch each other and are in a uniform temperature area in the furnace; 5. After 100 hours of oxidation, take out the sample, cool it to room temperature in a desiccator, and then accurately weigh its final mass; 6. According to the formula: weight gain rate = [(final mass - initial mass) / (sample surface area × oxidation time)], calculate the weight gain rate of each group of samples and take the average value as the test result; High-temperature oxidation resistance is a measure of the ability of a material to resist oxidation in a high-temperature aerobic environment. According to the experimental results, after 100 hours at 800°C, the weight gain rate of the conventional stainless steel wire is 0.5 mg / cm²・h, indicating that a relatively obvious oxidation reaction has occurred on its surface; the weight gain rate of Example 1 is 0.2 mg / cm²・h, that of Example 2 is 0.25 mg / cm²・h, and that of Example 3 is 0.15 mg / cm²・h; this is because the alloy elements of each layer in the multi-layer composite structure can form a dense oxide film at high temperature, preventing oxygen from further diffusing into the interior, thereby reducing the oxidation rate. Among them, Example 3 may perform better in high-temperature oxidation resistance due to the optimization of its material composition and manufacturing process; See also Figure 5 Fatigue performance comparison test data table Fatigue limit (MPa, 10^7 cycles): 1. Processing fatigue test samples, the shape and size of the samples of conventional stainless steel wire and each embodiment of the stainless steel wire shall comply with the fatigue test standard (ASTME466), and the number of samples in each group shall be at least 5; 2. Install and debug the fatigue testing machine, set the test frequency to 100Hz, and the stress ratio R=-1 (symmetrical tension and compression cycle); 3. First, estimate a higher stress level, install the sample on the fixture of the fatigue testing machine, and start the test; 4. Observe the fatigue failure of the sample during the test and record the number of cycles at failure; 5. If damage occurs within 10^7 cycles, reduce the stress level; if damage does not occur, increase the stress level and repeat the test until the maximum stress value that does not cause damage under 10^7 cycles is found, which is the fatigue limit. Take the average value of the test results of each group of samples; The fatigue limit is the maximum stress value that a material can withstand infinite cycles without being damaged under the action of alternating loads. According to the experimental results, the fatigue limit of the traditional stainless steel wire is 300MPa, while the fatigue limit of the multilayer composite stainless steel wire of Example 1 is increased to 450MPa, 420MPa of Example 2, and 500MPa of Example 3. This is due to the design of the multilayer composite structure. The good combination between the layers makes the stress distribution more uniform under the action of alternating loads, reduces the stress concentration phenomenon, and the coordinated work of the central core material, the middle transition layer, and the outer wear-resistant layer can better withstand repeated tensile and compressive stresses, thereby significantly improving the fatigue limit; Fatigue life (times, under 350MPa stress): 1. Prepare samples of the same specifications as those for the fatigue limit test, with the number of samples in each group being no less than 3; 2. Debug the fatigue testing machine, set the stress level to 350MPa, the frequency to 100Hz, and the stress ratio R=-1; 3. Install the sample on the fatigue testing machine, start the test and start counting; 4. Record the number of cycles of each sample under 350MPa stress until fatigue failure occurs, and take the average value as the fatigue life test result of this group of samples under this stress; According to the experimental results, under a fixed stress of 350MPa, the fatigue life of the conventional stainless steel wire is 5×10^5 times; the fatigue life of the multilayer composite stainless steel wire of Example 1 reaches 2×10^6 times, that of Example 2 is 1.8×10^6 times, and that of Example 3 is 3×10^6 times; this further illustrates the advantages of the multilayer composite structure in improving fatigue performance, and the characteristics of the materials of each layer and the interface bonding state can effectively delay the initiation and propagation of fatigue cracks, so that it can withstand more cyclic loading at the same stress level; See also Figure 6 Low temperature toughness comparison test data table Impact toughness (-40°C, J / cm²): 1. Process and prepare standard impact specimens. The shape and size of the specimens of the conventional stainless steel wire and the stainless steel wire of each embodiment shall comply with the impact test standard (GB / T229-2007). The number of specimens in each group shall be at least 5; 2. Adjust the pendulum energy of the impact tester to the appropriate range, and set the sample cooling device to -40°C, ensuring that the temperature uniformity is within ±2°C; 3. Place the sample in a cooling device and keep it warm for 30 minutes until its temperature reaches -40°C; 4. Quickly remove the sample from the cooling device and install it on the support of the impact tester, ensuring that the sample is placed correctly and firmly; 5. Release the pendulum to impact the sample, record the residual energy after the pendulum impacts the sample, and calculate the impact toughness of each group of samples according to the formula: impact toughness = (initial energy of the pendulum - residual energy of the pendulum) / cross-sectional area at the notch of the sample, and take the average value as the test result; Impact toughness reflects the ability of a material to resist impact loads at low temperatures without brittle fracture. According to the experimental results, the impact toughness of conventional stainless steel wire at -40°C is 50 J / cm², the multilayer composite stainless steel wire of Example 1 is 80 J / cm², Example 2 is 75 J / cm², and Example 3 is 90 J / cm². This is because the combination of alloy elements in the multilayer composite structure and the interaction between the layers can maintain good structural integrity at low temperatures, inhibit the formation of brittle phases, and enable the material to absorb more energy through plastic deformation when impacted, thereby improving the impact toughness. Low temperature elongation at break (%, -40°C): 1. Prepare standard tensile specimens, similar to those for high temperature tensile strength test, but consider the special requirements of low temperature test. Each group of specimens should be at least 3; 2. Set the test chamber temperature of the low-temperature tensile testing machine to -40°C and stabilize the temperature within a fluctuation range of ±2°C; 3. Install the sample on the fixture of the low-temperature tensile testing machine, ensuring that the clamp is firm and the axis of the sample is consistent with the direction of tension; 4. Apply tension to the sample at a constant tensile rate (0.5 mm / min) and record the tension and displacement data until the sample breaks; 5. According to the displacement at fracture and the original gauge length of the specimen, calculate the low-temperature fracture elongation of each group of specimens according to the formula: fracture elongation = [(gauge length at fracture - original gauge length) / original gauge length] × 100%, and take the average value as the test result; The low-temperature fracture elongation indicates the degree of plastic deformation of a material when it fractures at low temperature. According to the experimental results, the fracture elongation of the conventional stainless steel wire at -40°C is 10%, while that of the multilayer composite stainless steel wire of Example 1 is 18%, that of Example 2 is 15%, and that of Example 3 is 22%. This indicates that the multilayer composite structure has better plasticity in a low-temperature environment. The cooperative deformation ability of each layer of material at low temperature enables a greater degree of plastic stretching to occur before fracture, thus avoiding sudden brittle fracture. This is a very important performance improvement for stainless steel wire used under low-temperature conditions. See also Figure 7 Hardness and wear resistance comprehensive comparison test data table Rockwell hardness (HRC): 1. Prepare a flat sample surface. The surface roughness of the samples of the conventional stainless steel wire and the stainless steel wire of each embodiment shall comply with the Rockwell hardness test standard (GB / T230.1-2018). The number of samples in each group shall be at least 3; 2. Select a suitable Rockwell hardness tester, install the HRC hardness test indenter, and adjust the hardness tester to zero position; 3. Place the sample on the workbench of the hardness tester, slowly apply the initial test force (98.07N) to ensure good contact between the indenter and the sample surface, and then adjust the hardness tester pointer to zero; 4. Continue to apply the main test force, keep it for 4 seconds, then remove the main test force, keep the initial test force, read the hardness value on the hardness tester dial, test each sample at least 3 times at different positions, take the average value as the Rockwell hardness value of the sample, and take the average value of each group of sample results as the final test data; Hardness is the ability of a material to resist local plastic deformation. According to the experimental results, the Rockwell hardness of the conventional stainless steel wire is 25HRC, while the multilayer composite stainless steel wire of Example 1 reaches 40HRC, Example 2 reaches 38HRC, and Example 3 reaches 42HRC. This is mainly due to the extremely high hardness of the tungsten carbide particles added to the outer wear-resistant layer, and the good organizational structure and interface bonding formed during the manufacturing process of the entire multilayer composite structure, which significantly improves the overall hardness and can better resist the intrusion and wear of external objects. Wear test (wear volume, mm³, 1000 revolutions on a specific wear test machine): 1. Prepare wear test samples of the same shape and size. The samples of the conventional stainless steel wire and the stainless steel wire of each embodiment can be cylindrical or block-shaped. The number of samples in each group is at least 3; 2. Select a pin-on-disc wear tester, install the fixture for fixing the sample and the grinding material (grinding wheel or ceramic disc of a specific hardness), and set the speed of the tester to, for example, 200 rpm and the loading force to a constant value of 100 N; 3. Accurately measure and record the initial dimensions (diameter and height) of the sample in order to calculate the initial volume; 4. Install the sample on the fixture of the wear tester so that it is in good contact with the grinding material; 5. Start the wear tester and stop the test after running for 1000 revolutions; 6. Take the worn sample and accurately measure its size again. Calculate the wear volume based on the volume change before and after wear. The formula is: wear volume = initial volume - volume after wear. The average value of each group of sample results is taken as the final test data. In the wear test, the wear volume of the conventional stainless steel wire after running 1000 revolutions on a specific wear test machine is 20 mm³, while the wear volume of the multi-layer composite stainless steel wire of Example 1 is only 5 mm³, that of Example 2 is 8 mm³, and that of Example 3 is 3 mm³. This is because the high hardness of the outer wear-resistant layer and the uniform distribution of tungsten carbide particles effectively resist abrasive wear and adhesive wear during the wear process. At the same time, the intermediate transition layer and the central core material provide good support for the outer layer, ensuring the stability of the structure during the wear process, thereby greatly reducing the wear volume and reflecting excellent wear resistance. Therefore, based on the above embodiment and compared with the conventional stainless steel wire manufacturing method, there are the following differences and differences in the process of preparing the central core material: Heating temperature: The conventional preparation method usually heats the 304 stainless steel blank to 900°C-1000°C, while the present invention heats it to 1100°C-1200°C. The higher heating temperature helps the internal structure of the blank to be more fully homogenized, providing a better foundation for subsequent grain refinement. Insulation time: The traditional method has an insulation time of only 1-1.5 hours, while the present invention extends it to 2-3 hours, so that the alloy elements have more time to diffuse, which is beneficial to improving the uniformity of the overall performance of the material; Wire drawing process: The compression ratio of traditional wire drawing dies is fixed at about 1.2 and the number of passes is small. The initial compression ratio of the present invention is 1.3, and it is gradually increased by 0.1 for multiple wire drawing. The traditional work hardening rate is controlled at 20%-25%, while the present invention is controlled at 30%-40%. More sophisticated and reasonable wire drawing parameter settings can further refine the grains and improve the strength of the core material. Cooling method: Traditionally, it is natural cooling or simple air cooling. The present invention adopts annealing heat treatment under protective atmosphere of argon gas, with annealing temperature at 800℃-900℃ and strictly controlling cooling rate at 50℃ / h-80℃ / h. This method can effectively eliminate the internal stress caused by work hardening and stabilize the core material performance. Therefore, the tensile strength of the core material prepared by the traditional method is usually 500MPa-700MPa. The present invention, through the above-mentioned optimized data control, enables the tensile strength of the core material to reach no less than 1200MPa, which significantly improves the strength, provides a strong guarantee for the use of the entire multi-layer composite structure stainless steel wire under high stress conditions, solves the problem of insufficient strength of traditional 304 stainless steel wire, and makes the internal structure of the core material more uniform and the performance more stable; Differences in the process of coating and thermal diffusion of the intermediate transition layer: Thermal spraying parameters: conventionally, ordinary thermal spraying methods such as arc spraying are adopted, with hydrogen flow rate of 10L / min-12L / min, oxygen flow rate of 20L / min-25L / min, powder feeding amount of 20g / min-25g / min, spraying distance of 100mm-120mm, and spray gun moving speed of 200mm / s-300mm / s; the present invention adopts supersonic flame spraying, with hydrogen flow rate of 15L / min-20L / min, oxygen flow rate of 30L / min-40L / min, powder feeding amount of 30g / min-40g / min, spraying distance of 150mm-200mm, and spray gun moving speed of 300mm / s-500mm / s. The parameter setting of the present invention is more accurate and the range is more reasonable, which can ensure that the transition layer alloy powder is evenly and densely coated on the core material surface; Thermal diffusion conditions: The traditional thermal diffusion treatment is rough, with a temperature of 800℃-900℃, a time of 1-2 hours, and unstable heating and cooling rates. In the present invention, under an environment with a vacuum degree better than 5×10⁻³Pa, the thermal diffusion temperature is 1000℃-1100℃, the thermal diffusion time is 3 hours, the heating rate is 10℃ / min-15℃ / min, and the cooling rate is 8℃ / min-12℃ / min. The precise thermal diffusion conditions are conducive to the full diffusion of alloy elements at the interface to form a strong bond. Therefore, under the traditional method, the bonding strength between the transition layer and the core material is generally 100MPa-200MPa, which is prone to delamination and affects the stability of the multi-layer structure. The present invention optimizes data control to ensure that the bonding strength between the intermediate transition layer and the central core material is not less than 300MPa, effectively avoiding delamination, ensuring the stability and reliability of the multi-layer composite structure during processing and use, and extending the service life of the product. Differences in the process of preparing the outer wear-resistant layer: Deposition process: Traditionally, electroplating or simple coating process is used. Electroplating has environmental pollution problems and poor coating quality. The deposition rate of simple coating process is 5μm / h-8μm / h, the deposition temperature is 300℃-350℃, and the deposition pressure is 1Pa-1.5Pa. The present invention adopts magnetron sputtering deposition process, with a deposition rate of 10μm / h-15μm / h, a deposition temperature of 400℃-500℃, and a deposition pressure of 2Pa-3Pa. It can also accurately control various parameters to ensure process stability. Wear-resistant particle treatment: When wear-resistant particles are introduced in the traditional way, the distribution is uneven, the volume ratio is 5%-8% and there is no effective dispersion treatment; the present invention introduces tungsten carbide particles with a volume ratio of 10% during the deposition process, and uses ultrasonic dispersion treatment (ultrasonic frequency is 20kHz-30kHz, ultrasonic time is 30min-60min, and the dispersion medium is anhydrous ethanol) to make the particles evenly dispersed in the outer wear-resistant layer; Therefore, the outer wear-resistant layer prepared by the traditional process has uneven thickness, hardness of 400HV-500HV, and limited wear resistance; the outer wear-resistant layer prepared by the present invention can be precisely controlled at 0.3mm in thickness, and the hardness reaches 600HV, which has good wear resistance, greatly improves the service life of the stainless steel wire under high friction conditions, and avoids the environmental problems caused by electroplating, thereby improving the overall quality and performance of the product; Differences in the process of final heat treatment: The traditional method usually has no special final heat treatment step, or is just a simple low-temperature tempering, and there is no precise control over the temperature, time, and heating rate; the present invention performs the final heat treatment under a nitrogen protective atmosphere, the heat treatment temperature is 500°C-600°C, the heat treatment time is 1 hour, the heating rate is 12°C / min-18°C / min, and the temperature is cooled by furnace cooling, and each parameter is strictly controlled; Therefore, it is difficult to effectively optimize the organizational structure of stainless steel wire and eliminate residual stress with the traditional method, resulting in unstable overall performance. The present invention can further optimize the organizational structure, eliminate internal residual stress, improve the stability and uniformity of overall performance through a specific final heat treatment, and ensure that the stainless steel wire can stably exert excellent performance under various complex working conditions. To sum up, in the preparation process of multi-layer composite structure stainless steel wire, the data of each link of the present invention has been accurately and reasonably optimized and adjusted compared with the traditional preparation data, showing significant beneficial effects in many aspects from improving the strength of the central core material, enhancing the bonding firmness between layers, improving the performance of the outer wear-resistant layer to the stable optimization of the overall performance. It effectively solves many problems existing in the traditional preparation method in terms of product performance and structural stability, so that the prepared stainless steel wire can better meet the stringent requirements of modern industry for high-performance materials.

[0025] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the technical solution of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for manufacturing a multi-layer composite structure stainless steel wire, characterized in that: It includes a central core material, an intermediate transition layer and an outer wear-resistant layer; The manufacturing method of the multi-layer composite structure stainless steel wire is: S1: Preparation of the center core material: Select a stainless steel billet that meets the 304 stainless steel standard, heat it to 1100℃-1200℃, and keep it warm for 2-3 hours to make the billet homogenized; A multi-pass wire drawing process is adopted, and online tension detection and adjustment are performed after each wire drawing. The initial compression ratio of the wire drawing die is 1.3, and the wire drawing is performed in a manner of increasing by 0.1 each time until the stainless steel billet is processed into a high-strength stainless steel wire with a diameter of 2mm. The work hardening rate is controlled between 30% and 40% during the wire drawing process; The drawn stainless steel wire is subjected to annealing heat treatment under a protective atmosphere of argon, the annealing temperature is 800°C-900°C, the annealing time is 2 hours, and the cooling rate is controlled at 50°C / h-80°C / h; S2: Coating and thermal diffusion of the intermediate transition layer: The alloy powder is accurately prepared according to the alloy composition ratio of the intermediate transition layer, and the intermediate transition layer alloy powder is sprayed on the periphery of the central core material by supersonic flame spraying. During supersonic flame spraying, hydrogen and oxygen are used as fuel gases, with a hydrogen flow rate of 15L / min-20L / min, an oxygen flow rate of 30L / min-40L / min, a powder feeding amount of 30g / min-40g / min, a spraying distance of 150mm-200mm, and a spray gun moving speed of 300mm / s-500mm / s, so that the spraying thickness reaches 0.5mm; The sprayed composite wire is placed in a vacuum thermal diffusion furnace and subjected to thermal diffusion treatment in an environment with a vacuum degree better than 5×10⁻³Pa. The thermal diffusion temperature is 1000℃-1100℃, the thermal diffusion time is 3 hours, the heating rate is 10℃ / min-15℃ / min, and the cooling rate is 8℃ / min-12℃ / min, so that the intermediate transition layer and the central core material are firmly bonded. S3: The outer wear-resistant layer is deposited on the periphery of the intermediate transition layer by magnetron sputtering deposition process. The sputtering target material is an alloy target material matching the alloy composition of the outer wear-resistant layer. During the deposition process, the deposition rate is controlled to be 10μm / h-15μm / h, the deposition temperature is 400℃-500℃, and the deposition pressure is 2Pa-3Pa; During the deposition process, tungsten carbide particles are simultaneously introduced through a powder introduction device. Before introduction, the tungsten carbide particles are subjected to ultrasonic dispersion treatment, wherein the dispersion medium of the tungsten carbide particles is anhydrous ethanol, the ultrasonic frequency is 20kHz-30kHz, and the ultrasonic time is 30min-60min, so that the tungsten carbide particles are evenly dispersed in the outer wear-resistant layer, and finally an outer wear-resistant layer with a thickness of 0.3mm is formed; S4: The prepared stainless steel wire is subjected to a final heat treatment under a nitrogen protective atmosphere, the heat treatment temperature is 500°C-600°C, the heat treatment time is 1 hour, the heating rate is 12°C / min-18°C / min, and the cooling is carried out by furnace cooling to improve the overall performance of the steel wire, and finally a prepared multi-layer composite structure stainless steel wire is obtained.

2. The method for manufacturing a multi-layer composite structure stainless steel wire according to claim 1, characterized in that: In S2, the thermal spraying process adopts supersonic flame spraying, the gas flow rate during spraying is 15L / min-20L / min, and the powder feeding amount is 30g / min-40g / min.

3. The method for manufacturing a multi-layer composite structure stainless steel wire according to claim 1, characterized in that: In S3, the physical vapor deposition process is magnetron sputtering deposition, the sputtering power is 1000W-1500W, and the distance between the target material and the steel wire is 80mm.

4. The method for manufacturing a multi-layer composite structure stainless steel wire according to claim 1, characterized in that: The intermediate transition layer is wrapped around the outer periphery of the central core material. The intermediate transition layer is a stainless steel alloy layer with a specific alloy composition, and its thickness is 0.5 mm. The alloy composition ratio in the intermediate transition layer is: chromium 18%-22%, nickel 8%-12%, molybdenum 2%-4%, manganese 1.5%-2.5%, silicon 0.5%-1.5%, copper 0.3%-0.8% and trace amounts of niobium 0.05%-0.15% and vanadium 0.03%-0.08%, and the remainder is Fe and unavoidable impurities. The intermediate transition layer and the central core material are bonded by thermal diffusion, and the bonding strength is not less than 300MPa.

5. The method for manufacturing a multi-layer composite structure stainless steel wire according to claim 4, characterized in that: The central core material is a high-strength stainless steel wire with a tensile strength of not less than 1200 MPa and a diameter of 2 mm.

6. The method for manufacturing a multi-layer composite structure stainless steel wire according to claim 4, characterized in that: The outer wear-resistant layer is coated on the periphery of the intermediate transition layer. The outer wear-resistant layer is a stainless steel wear-resistant alloy layer that has undergone special heat treatment. The thickness is 0.3 mm and the hardness is 600 HV. The outer wear-resistant layer and the intermediate transition layer are combined through a physical vapor deposition process to form a dense bonding interface, and the element diffusion depth at the bonding interface is 0.05 mm.

7. The method for manufacturing a multi-layer composite structure stainless steel wire according to claim 4, characterized in that: The stainless steel material of the central core material is 304 stainless steel.

8. The method for manufacturing a multi-layer composite structure stainless steel wire according to claim 4, characterized in that: The stainless steel alloy composition of the intermediate transition layer also includes 0.5%-1.5% titanium, and the titanium element forms a titanium-rich diffusion layer at the interface between the intermediate transition layer and the central core material, and the thickness of the titanium-rich diffusion layer is 0.02 mm.

9. The method for manufacturing a multi-layer composite structure stainless steel wire according to claim 4, characterized in that: Tungsten carbide particles are added to the stainless steel wear-resistant alloy of the outer wear-resistant layer, the volume ratio of the tungsten carbide particles is 10%, and the tungsten carbide particles are evenly distributed in the wear-resistant layer.

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