Durability-enhanced flexible steel wire rope and processing technology thereof

Abstract

The invention relates to the technical field of flexible steel wire ropes, and discloses a durability-enhanced flexible steel wire rope and a processing technology thereof.The durability-enhanced flexible steel wire rope comprises, by mass, 98-105 parts of an alloy steel wire core; 5 to 15 parts of a ceramic nano composite outer coating; 2 to 10 parts of a self-repairing polymer middle coating layer; 1-5 parts of a high-adhesion polymer inner coating; 1-8 parts of a polymer composite lubricant; 0.5 to 3 parts of nanometer lubricating particles; according to the process, through collaborative design of multiple functional coatings and a lubricating system and combination of a heat treatment process, the corrosion resistance and the wear resistance of the steel wire rope are remarkably improved, and the service life is remarkably prolonged. Through the collaborative design of the high alloy steel core, the ceramic nano coating, the self-repairing middle layer, the three-layer coating structure and the polymer nano lubricating system, the corrosion resistance, the fatigue resistance, the wear resistance and the self-repairing capacity of the steel wire rope are improved, the service life is prolonged, and the maintenance cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible steel wire ropes, and particularly to a flexible steel wire rope with enhanced durability and its processing technology. Background Art

[0002] As a key load-bearing and transmission component, steel wire ropes are widely used in complex environments such as mines, bridges, hoisting, and ocean engineering. However, under harsh conditions such as high salt, high humidity, and heavy load alternating stress, traditional steel wire ropes are prone to corrosion and fatigue cracks, threatening structural safety. Although existing technologies reduce external corrosion and wear by applying protective coatings, these traditional coatings are insufficient in mechanical strength, adhesion, and self-healing ability, and are difficult to cope with complex stresses and environmental disturbances.

[0003] In addition, during the long-term use of steel wire ropes, damage such as microcracks will occur due to load cycling and microscopic wear. Traditional protective coatings cannot self-heal, resulting in the rapid intrusion of corrosion factors and accelerating fatigue failure. At the same time, the adhesion between the coating and the steel wire surface is insufficient, and it is easy to fall off under thermal cycling or alternating loads. In addition, the improvement of the lubrication performance of steel wire ropes mainly relies on ordinary lubricating greases or oil films. However, during high-frequency friction and long-term operation, these lubrication methods are prone to failure or shedding, and it is difficult to form a durable and stable lubricating layer, thereby increasing wear and energy consumption. Therefore, the present invention proposes a flexible steel wire rope with enhanced durability and its processing technology to solve the deficiencies of the existing technology. Summary of the Invention

[0004] In view of the deficiencies of the existing technology, the present invention provides a flexible steel wire rope with enhanced durability and its processing technology, which solves the problems of easy corrosion, easy wear, and lack of self-healing ability of steel wire ropes in complex environments.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A flexible steel wire rope with enhanced durability, the flexible steel wire rope comprises the following components in parts by mass: Alloy steel wire core: 98 - 105 parts; Ceramic nano-composite outer coating: 5 - 15 parts; Self-healing polymer middle coating: 2 - 10 parts; High-adhesion polymer inner coating: 1 - 5 parts; Polymer composite lubricant: 1 - 8 parts; Nano-lubricating particles: 0.5 - 3 parts.

[0006] The alloy steel wire core, as the core component of the present invention, bears the main mechanical load of the flexible steel wire rope. The wire core is made of a special proportion of alloy steel material, specifically including: containing chromium, nickel, molybdenum, carbon, and the balance of iron.

[0007] The addition of elements such as chromium, nickel, and molybdenum effectively improves the corrosion resistance, oxidation resistance, and high-temperature performance of steel. Chromium has good oxidation resistance and can form a stable protective film on the surface of the steel wire, preventing moisture and corrosive media in the external environment from entering the interior of the steel wire and extending the service life of the steel wire. The addition of nickel improves the toughness and ductility of the steel. Molybdenum can enhance the heat resistance and anti-wear performance of the steel wire, further improving its adaptability in harsh environments.

[0008] The heat treatment process of alloy steel wire refines the grains of the steel, improving its crack resistance and fatigue resistance. Through precise heat treatment processes (such as annealing and tempering), the microstructure of the steel wire is optimized, making it more stable during long-term use and reducing the occurrence of fatigue fractures.

[0009] The ceramic nano-composite outer coating is the key functional layer in the present invention. Its main components are a composite of alumina nanoparticles and a silica sol matrix. This coating is formed by a sol-gel process or a high-pressure spraying technique, and the thickness is controlled within 10 - 30 microns. The content of alumina nanoparticles is 5 - 12 parts, the content of the silica sol matrix is 3 - 8 parts, and the mass ratio of alumina to silica sol is 2:1 - 3:1.

[0010] The ceramic nano-composite coating has excellent hardness, wear resistance, and corrosion resistance. As a hard ceramic material, alumina can effectively enhance the anti-wear performance of the coating, preventing the steel wire rope from being worn during the friction process. Especially under high-strength and high-friction working conditions, it can extend the service life of the steel wire rope. The silica sol matrix not only enhances the mechanical strength of the coating but also provides better adhesion.

[0011] The ceramic nanoparticles in the coating combine through a sol-gel process at high temperatures to form a dense surface protective layer, reducing the erosion of the external environment on the steel wire, especially preventing the intrusion of corrosive media such as acidic and alkaline substances and seawater, ensuring that the steel wire maintains stable performance for a long time.

[0012] The self-healing polymer intermediate coating mainly contains polyurethane or epoxy resin as the matrix material and is embedded with self-healing microcapsules. The microcapsules are filled with chemical substances with self-healing functions. When the surface of the steel wire is scratched or slightly damaged, the microcapsules rupture and release the self-healing substances, effectively repairing the micro-damage. The particle size range of the self-healing microcapsules is 50 - 200 nanometers.

[0013] The key mechanism of the self-healing polymer lies in the release and reaction of the chemicals inside the microcapsules. The polyurethane or epoxy resin matrix has good mechanical strength and weather resistance, and the addition of microcapsules enables the coating to actively repair after being damaged, thus restoring its original function and protective effect. This mechanism is particularly suitable for preventing large-scale corrosion expansion caused by small-scale damage to the coating, and extends the service life of the coating and the steel wire rope.

[0014] The high-adhesion polymer inner coating is mainly composed of polyvinyl alcohol or polystyrene materials, and the coating thickness is controlled between 3 and 8 microns. This coating is located between the steel wire surface and the self-healing polymer middle coating, playing a role in enhancing the adhesion of the coating.

[0015] Polyvinyl alcohol and polystyrene have extremely high adhesion and excellent weather resistance, forming a firm bonding force between the coating and the steel wire, effectively preventing the coating from peeling off or separating from the substrate. In addition, this coating also has excellent anti-permeability, which can effectively block external moisture and corrosive substances, and increase the corrosion resistance of the steel wire.

[0016] The polymer composite lubricant is composed of ultra-high molecular weight polyethylene and polytetrafluoroethylene, and is mixed in a mass ratio of 2:1 to 3:1. This lubricant is formed by melt coating or electrostatic spraying technology, and the coating thickness is 5 to 15 microns.

[0017] Ultra-high molecular weight polyethylene has an extremely low coefficient of friction, which can effectively reduce the friction and wear between steel wires. Especially in high-load and high-frequency operating environments, it can significantly reduce the heat and wear generated by friction, and extend the service life of the steel wire. Polytetrafluoroethylene further reduces the coefficient of friction and provides a more durable lubricating effect. In addition, the polymer composite lubricant also has good chemical corrosion resistance and high-temperature resistance, enabling the steel wire rope to maintain a low friction force in harsh environments and enhancing its stability.

[0018] The nano-lubricating particles include nano-aluminum oxide or nano-silicon nitride, with a particle size range of 20 to 100 nanometers, and are uniformly dispersed in the polymer composite lubricant.

[0019] The nano-particles, as solid lubricants in the lubricating system, can form a protective film on the friction interface, reducing the direct contact between the metal surfaces, thus effectively reducing the coefficient of friction and wear. Both nano-aluminum oxide and nano-silicon nitride have high hardness and good anti-wear ability, and they play a role in enhancing the wear resistance and lubricating performance in the lubricant. Due to the high surface area characteristics of the nano-particles, they can better combine with the substrate material, enhancing the durability and stability of the lubricating layer.

[0020] Preferably, the alloy steel wire core is made of an alloy material composed of 5-15 parts of chromium, 3-10 parts of nickel, 1-5 parts of molybdenum, 0.1-0.5 parts of carbon, and the balance of iron, and obtains predetermined mechanical properties through a heat treatment process; the ceramic nano-composite outer coating includes a composite of 5-12 parts of alumina nano-particles and 3-8 parts of silica sol matrix, and the mass ratio of alumina nano-particles to silica sol matrix is 2:1-3:1, and is formed by a sol-gel process or a high-pressure spraying method, with a thickness of 10-30 microns.

[0021] Preferably, the self-healing polymer intermediate coating includes polyurethane or epoxy resin as the matrix and incorporates 0.1-1 part of self-healing microcapsules, and the particle size of the microcapsules is 50-200 nanometers; the high-adhesion polymer inner coating is made of polyvinyl alcohol or polystyrene material, and is attached between the steel wire surface and the intermediate coating, with a thickness controlled within 3-8 microns.

[0022] Preferably, the polymer composite lubricant includes 2-6 parts of ultra-high molecular weight polyethylene and 1-3 parts of polytetrafluoroethylene, and the mass ratio of ultra-high molecular weight polyethylene to polytetrafluoroethylene is 2:1-3:1, and a lubricating layer is formed by melt coating or electrostatic spraying; the nano-lubricating particles are nano-alumina or silicon nitride particles, with a particle size of 20-100 nanometers, and are uniformly dispersed in the polymer composite lubricant to form a stable lubricating structure.

[0023] The present invention also provides a soft steel wire rope for enhancing durability and its processing technology, including the following steps: S1. Provide an alloy steel material containing chromium, nickel, molybdenum, carbon, and iron, and process it into a wire core material. S2. Coating a high-adhesion polymer inner coating, a self-healing polymer intermediate coating, and a ceramic nano-composite outer coating on the surface of the wire core material in sequence. S3. Perform heat treatment on the coated steel wire, including annealing treatment and tempering treatment, for adjusting the organizational structure. S4. Coat a composite lubricant containing a polymer material and nano-lubricating particles on the surface of the heat-treated steel wire. S5. Complete the curing and cooling treatment to obtain a finished soft steel wire rope for enhancing durability.

[0024] Preferably, in the step S1, the diameter range of the wire core material is 0.2-1.5 millimeters, and after the following treatment process, the final diameter accuracy is controlled within plus or minus 0.05 millimeters: Select a multi-pass wire drawing process to gradually reduce the wire diameter so that the wire gradually reaches the target diameter; during the stretching process, use nitrogen coolant to cool the wire to ensure that the surface temperature of the wire remains at 50°C-100°C during the stretching process, and the wire drawing rate is controlled at 0.1-1.0 meters per second to obtain the required diameter range of 0.2-1.5 millimeters. After wire drawing, the steel wire is annealed at an annealing temperature in the range of 550°C to 650°C for 30 to 90 minutes. During the annealing process, a protective atmosphere of nitrogen or argon is used, and the cooling rate after annealing is controlled within 10°C per minute; During the processes of wire drawing and after annealing, the diameter of the steel wire in each process is ensured to be maintained within ±0.05 mm by using a laser diameter gauge and an online sensor.

[0025] Preferably, in step S2, the coating is completed by a multi-layer spraying process, and the specific steps are as follows: The high-adhesion polymer inner coating uses polyvinyl alcohol or polystyrene material, with a coating thickness of 3 to 8 μm, and is cured at a temperature of 50°C to 100°C for 10 to 15 minutes after coating; The self-healing polymer middle coating is a composite material of polyurethane or epoxy resin and self-healing microcapsules, with a coating thickness of 5 to 15 μm, a microcapsule particle size of 50 to 200 nm, and is cured at a temperature of 60°C to 120°C for 10 to 20 minutes after coating; The ceramic nano-composite outer coating is formed by compounding nano-particles of aluminum nitride or aluminum oxide with a sol matrix, with a coating thickness of 10 to 30 μm, a curing temperature of 150°C to 200°C, and a curing time of 15 to 30 minutes.

[0026] Preferably, in step S3, the annealing treatment temperature is 550°C to 650°C, the treatment time is 60 to 120 minutes, the annealing process adopts a uniform heating and cooling method, and a protective atmosphere of nitrogen or argon is used; the tempering treatment temperature is 180°C to 220°C, the tempering time is 30 to 60 minutes, the tempering process uses a hot air circulation furnace, and the surface hardness after tempering is 45 to 55 HRC.

[0027] Preferably, in step S4, the coating method of the composite lubricant is melt spraying or electrostatic spraying, and the ratio of the lubricants is as follows: Ultra-high molecular weight polyethylene 2 to 6 parts; polytetrafluoroethylene 1 to 3 parts; nano-lubricating particles 0.5 to 2 parts, the nano-particles are nano-aluminum oxide or nano-silicon nitride, and the particle size range is 20 to 100 nm; during the coating process, the spraying pressure is controlled at 1.5 to 3.0 MPa, the coating speed is 2 to 5 m / min, and the coating thickness is 5 to 15 μm.

[0028] Preferably, in step S5, the curing temperature range after coating is 150°C to 250°C, the curing time is 30 to 60 minutes. During the curing process, an oven or infrared radiation is used for heating, and after curing, it is naturally cooled to room temperature, with a cooling rate of 5°C to 15°C per minute. The surface coating uniformity of the soft steel wire rope should be not less than 95%, the surface adhesion conforms to the ISO2409 standard, and the coating thickness difference is less than plus or minus 2 microns to ensure the quality stability of the finished product.

[0029] The present invention provides a soft steel wire rope with enhanced durability and its processing technology. It has the following beneficial effects: 1. The present invention adopts the technical solution of a high-alloy steel wire core and a ceramic nano-composite outer coating, achieving the technical effect of significantly improving the corrosion resistance and anti-fatigue performance of the steel wire rope. Compared with the technical solutions of single coatings or traditional steel wire materials in the prior art, the present invention effectively solves the problems of easy corrosion and fatigue crack propagation of traditional steel wire ropes, thereby extending the service life of the steel wire rope in harsh environments and reducing early failures caused by environmental factors.

[0030] 2. The present invention adopts the technical solution of a self-healing polymer intermediate coating, achieving the technical effect of being able to actively repair micro-cracks and damages. Compared with the simple protective coatings in the prior art, the self-healing layer of the present invention can automatically repair when micro-damages occur, avoiding the expansion of damages, thereby maintaining the long-term stability of the coating and the steel wire rope. While improving the durability of the steel wire rope, it significantly reduces the maintenance cost and downtime.

[0031] 3. The present invention adopts the collaborative design of a three-layer coating (inner adhesion layer + self-healing layer + wear-resistant layer), achieving the technical effects of improving wear resistance, adhesion, and self-healing ability. Compared with the solutions using single coatings or simple composite materials in the prior art, the three-layer coating of the present invention forms a multi-layer protective barrier on the surface of the steel wire rope, effectively reducing coating peeling, wear, and corrosion expansion during use, providing multi-functional collaborative protection, and greatly improving the working life of the steel wire rope.

[0032] 4. The present invention adopts the technical solution of a polymer composite lubricant and nano-lubricating particles, achieving the technical effect of reducing the friction coefficient and wear. Compared with the traditional lubrication or coating solutions in the prior art, the lubrication system of the present invention forms an efficient lubricating film on the friction interface through the addition of nano-lubricating particles, reducing the dynamic friction load of the steel wire rope, avoiding wire wear and damage caused by excessive friction, thereby improving the wear resistance and working efficiency of the steel wire rope. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] Please refer to Figure 1 : Example 1: Preparation Scheme of Standard Corrosion-Resistant Flexible Steel Wire Rope Raw Materials and Proportions: Alloy Steel Wire Core: 100 parts, Ceramic Nanocomposite Outer Coating (Aluminum Oxide / Silica Sol Matrix Composite): 10 parts, Self-Healing Polymer Intermediate Coating (Polyurethane and Microcapsules): 5 parts, High-Adhesion Polymer Inner Coating (Polyvinyl Alcohol): 3 parts, Polymer Composite Lubricant (Polyethylene and Polytetrafluoroethylene): 6 parts, Nano Lubricating Particles (Nano Aluminum Oxide): 1 part; Preparation Process: Treatment of Alloy Steel Wire Core: Select alloy steel materials containing chromium, nickel, molybdenum, carbon, and iron, process them into steel wires with a diameter of 3 mm using standard drawing processes, and perform annealing treatment to make them have high strength and toughness.

[0036] Coating of Ceramic Nanocomposite Outer Coating: Mix aluminum oxide nanoparticles and silica sol in a mass ratio of 10:3, and use the sol-gel process to coat the surface of the steel wire to form a protective coating with a thickness of 20 μm.

[0037] Coating of Self-Healing Polymer Intermediate Coating: Use a composite material of polyurethane and microcapsules to coat a 10-μm-thick self-healing coating on the steel wire to ensure active repair when microcracks appear.

[0038] Coating of Inner Adhesion Layer: Use polyvinyl alcohol as the base material to coat an inner adhesion layer with a thickness of 5 μm to ensure firm bonding between the coating and the surface of the steel wire.

[0039] Coating of Polymer Composite Lubricant: Mix polyethylene and polytetrafluoroethylene, and use the electrostatic spraying process to coat it on the surface of the steel wire to form a 5-μm-thick lubricating layer to effectively reduce the friction coefficient.

[0040] Dispersion of Nano Lubricating Particles: Uniformly disperse nano aluminum oxide particles in the lubricant and add them during the coating process to enhance the lubrication effect.

[0041] Example 2: Preparation Scheme of High-Strength Anti-Fatigue Flexible Steel Wire Rope Raw Materials and Proportions: Alloy steel wire core: 105 parts, ceramic nano-composite outer coating: 8 parts, self-healing polymer middle coating: 4 parts, high-adhesion polymer inner coating: 2 parts, polymer composite lubricant: 7 parts, nano-lubricating particles: 1 part; Preparation process: Treatment of alloy steel wire core: Select alloy steel, especially add a high amount of molybdenum and nickel, process it into a wire with a diameter of 2.5 mm by high-temperature drawing process, and carry out appropriate annealing treatment to improve its fatigue resistance and anti-cracking performance.

[0042] Coating of ceramic nano-composite outer coating: The ratio of alumina to silica sol matrix is 8:2. Use spraying process to coat the ceramic composite layer on the wire surface, and control the coating thickness at about 18 μm.

[0043] Coating of self-healing polymer middle coating: Select a mixture of epoxy resin and self-healing microcapsules, and use spraying technology to form a 10-μm-thick repair coating. This coating can quickly repair when micro-damage occurs and reduce the propagation of fatigue cracks.

[0044] Coating of inner adhesion layer: Use polystyrene as the base material, and use liquid coating method to coat the inner adhesion layer on the wire surface with a thickness of 4 μm to ensure that the subsequent coatings can adhere firmly.

[0045] Coating of polymer composite lubricant: Use a lubricant mixed with polytetrafluoroethylene and ultra-high molecular weight polyethylene, and coat to form a lubricating layer with a thickness of 8 μm to effectively reduce friction.

[0046] Dispersion of nano-lubricating particles: Add nano-silicon nitride particles to the lubricant to optimize the lubrication effect and ensure that the wire rope can reduce wear during use.

[0047] Example 3: Preparation plan for high-abrasion-resistance and high-stability soft wire rope Raw materials and ratios: Alloy steel wire core: 98 parts, ceramic nano-composite outer coating: 12 parts, self-healing polymer middle coating: 3 parts, high-adhesion polymer inner coating: 4 parts, polymer composite lubricant: 5 parts, nano-lubricating particles: 2 parts; Preparation process: Treatment of alloy steel wire core: Select high-strength alloy steel, and use heat treatment process (including annealing and tempering treatment) to ensure the strength and anti-wear performance of the wire, and finally make a wire with a diameter of 3 mm.

[0048] Coating of ceramic nano-composite outer coating: Mix alumina and silica sol in a ratio of 9:3, and coat by electrostatic spraying process to form an outer coating with a thickness of 20 μm, which can effectively improve the wear resistance and corrosion resistance of the wire.

[0049] Coating of the self-healing polymer intermediate layer: A composite of epoxy resin and self-healing microcapsules is used and sprayed on the surface of the steel wire to form a 6-μm thick repair layer for repairing small cracks on the surface.

[0050] Coating of the inner adhesion layer: Polyvinyl alcohol is used as the material for the inner adhesion layer to ensure the firm adhesion of the coating, and the coating thickness is controlled at 6 μm.

[0051] Coating of the polymer composite lubricant: A lubricant of polytetrafluoroethylene and ultra-high molecular weight polyethylene is coated on the surface of the steel wire to form a 5-μm thick lubricating film, reducing friction and extending the service life of the wire rope.

[0052] Dispersion of nano-lubricating particles: Nano-aluminum oxide particles are uniformly added to the lubricant to improve the lubrication effect and ensure excellent performance under high-friction conditions.

[0053] Comparative Example 1 Compared with Example 1, the coating amount of the ceramic nano-composite outer coating is reduced, and only 6 parts of the ceramic coating are used, and the rest are the same.

[0054] Comparative Example 2 Compared with Example 1, the steel wire core is replaced with low-alloy carbon steel instead of high-alloy steel, and the rest are the same.

[0055] Comparative Example 3 Compared with Example 1, the content of alumina in the ceramic nano-composite outer coating is reduced, and only silica sol is used, and the rest are the same.

[0056] Comparative Example 4 Compared with Example 1, a single-layer ceramic coating is used to replace the ceramic nano-composite coating, and the rest are the same.

[0057] Comparative Example 5 Compared with Example 2, the self-healing polymer intermediate layer is removed, and only the ceramic outer layer and the inner adhesion layer are used, and the rest are the same.

[0058] Comparative Example 6 Compared with Example 2, the self-healing layer is retained, but the concentration of the microcapsule component is reduced from the original 5 parts to 1 part, and the rest are the same.

[0059] Comparative Example 7 Compared with Example 2, only an epoxy resin layer is used to replace the self-healing polymer coating, and the rest are the same.

[0060] Comparative Example 8 Compared with Example 2, a non-self-healing polyurethane coating is used to replace the self-healing polymer layer, and the rest are the same.

[0061] Comparative Example 9 Compared with Example 3, the inner adhesion layer was removed, and only the self-healing layer and the ceramic wear-resistant layer were retained, and the rest were the same.

[0062] Comparative Example 10 Compared with Example 3, only a single ceramic wear-resistant layer was retained, the self-healing layer and the adhesion layer were not provided, and the rest were the same.

[0063] Comparative Example 11 Compared with Example 3, the thickness of the self-healing layer was reduced to 5 μm, and the rest were the same.

[0064] Comparative Example 12 Compared with Example 3, the thickness of the wear-resistant layer was increased to 25 μm, and the rest were the same.

[0065] Comparative Example 13 Compared with Example 1, the nano-lubricating particles were removed, and only ordinary polymer lubricants were used, and the rest were the same.

[0066] Comparative Example 14 Compared with Example 1, the lubricating layer was changed to ordinary industrial lubricating oil instead of polymer lubricant and nano-particles, and the rest were the same. Comparative Example 15 Compared with Example 1, the nano-lubricating particles were replaced with micron-sized particles (particle size > 1 μm), and the rest were the same.

[0067] Comparative Example 16 Compared with Example 1, the talcum powder component in the lubricant was increased to enhance the lubrication performance, and the rest were the same.

[0068] Comparative Example 17 Compared with Example 1, polytetrafluoroethylene (PTFE) was used instead of polyvinyl alcohol as the lubricating layer material, and the rest were the same.

[0069] Test Example 1: Corrosion resistance and fatigue resistance test Experimental purpose To compare the effects of different wire core materials (high alloy steel vs low alloy steel) and coating structures (ceramic composite vs simplified / reduced / substituted) on the corrosion resistance and fatigue resistance of wire ropes, so as to verify the technical advantages of Example 1.

[0070] Experimental samples Experimental methods and steps Salt spray corrosion experiment Steps: Clean and dry each wire rope sample.

[0071] Place it in a neutral salt spray test chamber (5% NaCl, temperature 35 ± 2 °C).

[0072] Observe and record the rust area and degree on the surface of the sample every 24 hours.

[0073] The total test time is 500 hours.

[0074] The rust area is rated according to the ISO9227 standard grade (0 - 5 levels).

[0075] Cyclic bending fatigue test (GB / T2611) Steps: Fix the sample on the wire rope bending fatigue testing machine.

[0076] Conduct bending cycles at a constant tension (such as 40% of the breaking strength).

[0077] Check whether cracks or broken wires appear on the surface every 1000 cycles.

[0078] Record the total number of cycles before fracture as the fatigue life index.

[0079] Experimental environment and settings Salt spray test chamber: Q-Fog SSP600 type, spray rate 1.5 mL / h.

[0080] Bending fatigue test: steel wheel diameter 400 mm, constant tension, speed 30 revolutions per minute.

[0081] Ambient temperature: 23 ± 2 °C; relative humidity: 55 - 65%.

[0082] The test data is as shown in Table 1 below: Table 1: Comparative test data of the corrosion resistance and fatigue performance of different samples Experimental summary Based on the test results of Experiment 1, the following conclusions can be drawn. First, there is an obvious synergistic effect between the high alloy steel core and the ceramic nano composite coating. The experiment shows that when the coating thickness reaches 12 μm, the rust area of the wire rope in the salt spray test is the smallest (2.3%), and its fatigue life reaches 19,870 times, showing remarkable corrosion resistance and fatigue resistance. This phenomenon is closely related to the action mechanism of the coating. The ceramic nano composite coating can effectively isolate the external corrosive medium from contacting the wire surface through its dense structure, preventing the occurrence of oxidation reactions. At the same time, the high hardness of the coating also enhances the anti-wear ability of the wire surface and reduces the propagation speed of fatigue cracks.

[0083] Secondly, when the coating thickness was reduced to 6 μm, although the ceramic coating still played a certain protective role, the thinning of the coating led to a larger area of rust (17.6%) and a shortening of the fatigue life (16,730 cycles). This result indicates that there is a direct relationship between the thickness of the coating and its corrosion resistance and fatigue resistance. The thinner the coating, the poorer the protective effect, especially in the stress concentration area. After the coating was damaged, it could not be repaired in time, thus accelerating the corrosion and fatigue failure of the steel wire. According to the previous mechanism analysis, the greater the thickness and density of the coating, the stronger the physical barrier it can provide, delaying the formation and expansion of cracks.

[0084] Finally, the combination of low-alloy carbon steel and ceramic coating performed worse than that of high-alloy steel. The low-alloy carbon steel itself has poor corrosion resistance and is prone to forming oxides on the surface, which limits the effect of the coating. The experimental results show that the surface of the wire rope with this combination has a larger rust area (24.8%), and its fatigue life is only 13,560 cycles. The effect of the coating is weakened by the defects of the wire core material, indicating that the effect of the coating is affected by the nature of the material itself. According to the mechanism analysis, the lower corrosion resistance and mechanical properties of low-alloy carbon steel make it difficult to maximize the coating protection effect, further accelerating the propagation of fatigue cracks and the occurrence of corrosion.

[0085] Experiment 2: Self-healing function and coating adhesion test Experimental purpose The purpose of this experiment is to evaluate the self-healing ability, coating adhesion and the impact on the overall durability of wire ropes with different coating designs (self-healing coatings and traditional coatings). By comparing the performance differences between the microcapsule self-healing coating and the non-self-healing coating, the advantages of the self-healing technology in Example 2 in extending the service life of wire ropes are verified.

[0086] Experimental samples Experimental methods and procedures Self-healing test (repair ability after damage) Steps: Clean the surface of each sample to ensure no oil stain.

[0087] Use a sharp tool (such as a blade) to create micro-damage (depth of 10 μm, width of 2 mm) in the artificially scratched area.

[0088] Let the scratched samples stand in an environment of 23 ± 2 °C and observe the repair situation within 24 hours.

[0089] Record the repair percentage 24 hours after scratching, that is, whether the scratch is completely filled, the repair rate and effect.

[0090] Adhesion test (tensile adhesion) Steps: Define areas on the surface of each sample for tensile adhesion testing.

[0091] Use a dedicated tensile testing machine to apply a tensile load at a speed of 50 mm / min, and record the maximum force that the coating can withstand before peeling off.

[0092] Record the coating adhesion strength (unit: N / mm²) and compare the adhesion values of different coatings.

[0093] Durability test (long-term load cycling) Steps: Fix the sample on a wire rope fatigue testing machine and apply a load cycle with 40% of the maximum working tensile force.

[0094] Check the coating damage after every 1000 cycles, and record the coating damage area and the propagation of fatigue cracks.

[0095] Record the fatigue life and durability performance of the sample.

[0096] Experimental environment and settings Self-healing test environment temperature: 23 ± 2°C, humidity: 60 ± 5%.

[0097] Adhesion test: Use an AG-5000 type electronic tensile machine, and the test range is 0 - 5000 N.

[0098] Durability test: Load testing machine MaxTensile3000 type, cycle speed 30 revolutions per minute.

[0099] The test data is as shown in Table 2 below: Table 2: Self-healing function and adhesion test data Experimental summary It can be seen from the experimental results that the self-healing polymer coating (S1) has significant advantages in terms of repair performance, adhesion, and fatigue life. High-concentration microcapsules (5%) can effectively repair the coating after scratching, with a repair rate reaching 92.5%, and the coating has strong adhesion (18.3 N / mm²), enabling the wire rope to have a longer service life. This result is consistent with the mechanism explanation. The self-healing function of the microcapsules in the polymer realizes rapid filling of the damage and restores the integrity of the coating by releasing repair materials in the damaged area. At the same time, the adhesion between the coating and the steel wire improves the durability and slows down the speed of coating peeling off.

[0100] In contrast, the low-concentration microcapsule coating (S2) showed poor performance, with a repair rate of only 55.1%, an adhesion of 10.4 N / mm², and a correspondingly shortened fatigue life. The different microcapsule concentrations directly affected the repair ability of the coating. At lower concentrations, the repair effect was insufficient to effectively repair the damaged area, resulting in a decline in the coating performance. This result further verified the close relationship between microcapsule concentration and self-repair effect.

[0101] Finally, the coatings without self-repair function (S3, S4, S5) generally showed poor performance and obvious deficiencies in terms of durability and adhesion. Coatings without self-repair ability are prone to breakage during stress application, which in turn leads to coating peeling and increased corrosion of the steel wire surface.

[0102] Experiment 3: Wear Resistance and Coating Synergy Test Experiment Purpose The purpose of this experiment is to verify the synergy effect of the three-layer coating design (inner adhesion layer + self-repair layer + wear-resistant layer) in improving the wear resistance of wire ropes, and to evaluate the influence of different coating combinations on the wear performance of wire ropes by comparing with single-layer coatings (such as ceramic coatings, polyurethane coatings, etc.).

[0103] Experiment Samples Experiment Methods and Procedures Friction and Wear Test Steps: Install each wire rope sample on the wear test machine.

[0104] Set the rotation speed of the friction machine to 30 revolutions per minute and apply a certain load (such as 100 N).

[0105] After every 2000 revolutions of the friction cycle, check the wear condition of the coating surface and record the damaged area of the coating.

[0106] Measure the change in coating thickness and the change in the friction coefficient between the coating and the steel wire.

[0107] Durability Test Steps: Fix the sample on the wire rope fatigue test machine and apply a load cycle with 40% of the maximum working tension.

[0108] After every 1000 cycles, check the coating damage condition and record the damaged area.

[0109] Record the fatigue life and wear amount of the sample.

[0110] Coating Adhesion Test Steps: Conduct a tensile adhesion test on the sample coating.

[0111] Apply the maximum tensile force to the surface of the coating with a fixed area, and record the adhesion strength between the coating and the steel wire.

[0112] Experimental environment and settings Friction and wear testing machine: Rotary Abraser type, friction wheel diameter 150 mm, load 100 N, speed 30 revolutions per minute.

[0113] Load fatigue testing machine: MaxTensile3000 type, constant load, cyclic frequency 30 revolutions per minute.

[0114] Ambient temperature: 23 ± 2 °C, humidity: 60 ± 5%.

[0115] The test data is as shown in Table 3 below: Table 3: Comparative test data of wear resistance and fatigue performance of different coating designs Experimental summary From the experimental results, the three-layer coating design (S1) shows the best performance in terms of wear resistance and fatigue life. The wear area is only 4.2%, the friction coefficient is relatively low (0.33), and the fatigue life reaches 18,500 times. This result supports the synergistic effect of the coating proposed in the mechanism analysis. The inner adhesion layer can improve the adhesion between the coating and the steel wire, the self-repair layer can repair in time when micro-damage occurs, and the ceramic wear-resistant layer effectively slows down the wear process. The three-layer coating not only improves the fatigue resistance of the steel wire but also extends the service life and maintains a relatively low friction coefficient.

[0116] When the inner adhesion layer is missing (S2), the wear resistance and adhesion of the coating both decrease. The wear area increases (8.7%), and the fatigue life also decreases (14,920 times). This phenomenon proves the importance of the coating adhesion in the overall coating performance. The weak adhesion between the coating and the steel wire easily leads to coating peeling and increased wear, thus reducing the durability.

[0117] In the single-layer coating group, the ceramic coating (S3) and the polyurethane coating (S4) respectively show a relatively large wear area and a relatively high friction coefficient. Especially the polyurethane coating shows the worst performance, with a wear area reaching 18.1%, a friction coefficient of 0.45, and a fatigue life of only 12,050 times. The disadvantage of the single-layer coating is that it cannot provide comprehensive protection, and it is easy for the steel wire to be exposed due to coating wear, thus accelerating the generation of fatigue cracks.

[0118] Experiment 4: Environmental stress corrosion test Experimental purpose This experiment aims to evaluate the corrosion resistance performance of different coatings in a thermal cycling environment, especially the performance stability under extreme temperature changes. By comparing the corrosion resistance and thermal cycling performance of multiple coatings (including Example 1, Example 2, and the comparative sample), the long-term stability and anti-corrosion ability of the coatings are verified.

[0119] Experimental samples Experimental methods and procedures Thermal cycling test Steps: Put each wire rope sample into a thermal cycling chamber, set the temperature change range from -40°C to 80°C, and the cycle time is 1 hour for cooling and 1 hour for heating, with a total of 30 cycles.

[0120] After every 10 cycles, check the coating damage situation, record the crack generation, coating peeling area, and appearance changes.

[0121] Measure any physical or chemical changes that occur in the coating after thermal cycling, such as cracks, peeling, etc.

[0122] Salt spray corrosion test Steps: In the salt spray corrosion chamber, set the temperature to 35°C and the salt spray concentration to 5% for the corrosion test.

[0123] Take out the samples once every 48 hours, check the coating corrosion situation, and record the corrosion area and the corrosion rate of the coating.

[0124] Measure the depth of surface corrosion of the coating, record the crack propagation and the size of the corrosion area.

[0125] Fatigue and wear test Steps: Place the sample on a fatigue testing machine and apply a load cycle with 40% of the maximum working tensile force.

[0126] After every 1000 cycles, record the wear, cracks, and corrosion on the coating surface.

[0127] Record the fatigue life of the coating and compare the corrosion resistance and high-temperature resistance of different coatings.

[0128] Experimental environment and settings Thermal cycling test: Temperature range from -40°C to 80°C, humidity 30%.

[0129] Salt spray corrosion test: Salt spray concentration 5%, temperature 35°C.

[0130] Fatigue test: Model MaxTensile3000, cyclic frequency 30 revolutions per minute, load set at 40% of the maximum working load.

[0131] The test data are shown in Table 4 below: Table 4: Test data of corrosion resistance and thermal cycle performance Experimental summary From the experimental results, the three-layer composite coating (S1) shows the best performance in terms of corrosion resistance and thermal cycle performance. The salt spray corrosion area is 5.4%, and the number of thermal cycle cracks is only 2, with a fatigue life of 21,000 times. This result is consistent with the mechanism analysis. The inner adhesion layer in the coating enhances the bonding force between the coating and the steel wire, the self-healing layer can timely fill the micro-cracks in the coating, and the ceramic wear-resistant layer greatly improves the high-temperature resistance and corrosion resistance of the coating. The synergistic effect of the three enables the coating to have strong comprehensive performance.

[0132] In contrast, the self-healing coating and wear-resistant coating (S2) show better performance. The salt spray corrosion area is 8.1%, the number of thermal cycle cracks is 5, and the fatigue life is 17,500 times. Although the self-healing coating can repair micro-damage, the combination of the single-layer ceramic coating and the polymer coating fails to provide complete high-temperature stability. Therefore, its performance is slightly inferior to that of the three-layer composite coating.

[0133] The single-layer coatings (S3, S4, S7) show poor performance in terms of corrosion resistance and high-temperature performance. Especially for the bare steel without coating (S6), both its corrosion area and thermal cycle damage area increase significantly, and the coating fails to provide any effective protection, resulting in extremely fragile performance of the steel wire rope. For coatings without self-healing ability, such as epoxy resin coating (S3) and polyurethane coating (S4), they are prone to cracks and peeling at high temperatures, and their durability is poor.

[0134] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A soft steel wire rope with enhanced durability, characterized in that: The soft steel wire rope comprises an alloy steel wire core, a high-adhesion polymer inner coating, a self-repairing polymer middle coating, a ceramic nano-composite outer coating and a polymer composite lubricant layer coated on the outermost layer, wherein nano-lubricating particles are dispersed in the polymer composite lubricant layer, and the components of the mass fractions of each part are as follows: Alloy steel wire core: 98-105 parts; Ceramic nanocomposite outer coating: 5-15 parts; Self-healing polymer middle coating: 2-10 parts; High adhesion polymer inner coating: 1 to 5 parts; Polymer composite lubricant: 1 to 8 parts; Nano-lubricating particles: 0.5 to 3 parts.

2. A soft steel wire rope with enhanced durability according to claim 1, characterized in that: The alloy steel wire core is made of an alloy material containing 5 to 15 parts of chromium, 3 to 10 parts of nickel, 1 to 5 parts of molybdenum, 0.1 to 0.5 parts of carbon, and a balance of iron, and obtains predetermined mechanical properties through a heat treatment process; the ceramic nano-composite outer coating includes a composite of 5 to 12 parts of aluminum oxide nano-particles and 3 to 8 parts of a silica sol matrix, and the mass ratio of aluminum oxide nano-particles to silica sol matrix is ​​2:1 to 3:1, and is formed by a sol-gel process or a high-pressure spraying method, with a thickness of 10 to 30 microns.

3. A soft steel wire rope with enhanced durability according to claim 1, characterized in that: The self-healing polymer middle coating includes polyurethane or epoxy resin as a matrix, and is embedded with 0.1 to 1 parts of self-healing microcapsules, and the particle size of the microcapsules is 50 to 200 nanometers; the high-adhesion polymer inner coating is polyvinyl alcohol or polystyrene material, which is attached between the steel wire surface and the middle coating, and the thickness is controlled at 3 to 8 microns.

4. A soft steel wire rope with enhanced durability according to claim 1, characterized in that: The polymer composite lubricant includes 2 to 6 parts of ultra-high molecular weight polyethylene and 1 to 3 parts of polytetrafluoroethylene, and the mass ratio of ultra-high molecular weight polyethylene to polytetrafluoroethylene is 2:1 to 3:

1. The lubricating layer is formed by melt coating or electrostatic spraying. The nano-lubricating particles are nano-aluminum oxide or silicon nitride particles with a particle size of 20 to 100 nanometers, which are uniformly dispersed in the polymer composite lubricant to form a stably distributed lubricating structure.

5. A processing technology for a soft steel wire rope with enhanced durability, applied to a soft steel wire rope with enhanced durability as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Provide alloy steel materials containing chromium, nickel, molybdenum, carbon and iron, and process them into steel wire core materials; S2, sequentially coating a high-adhesion polymer inner coating, a self-healing polymer middle coating and a ceramic nanocomposite outer coating on the surface of the steel wire core material; S3, heat treating the coated steel wire, including annealing and tempering, to adjust the organizational structure; S4, coating a composite lubricant comprising a polymer material and nano-lubricating particles on the surface of the heat-treated steel wire; S5. Complete the curing and cooling process to obtain a soft steel wire rope product with enhanced durability.

6. A process for processing a soft steel wire rope with enhanced durability according to claim 5, characterized in that: In step S1, the diameter of the steel wire core material ranges from 0.2 to 1.5 mm. After the following processing, the final diameter accuracy is controlled within plus or minus 0.05 mm: A multi-pass wire drawing process is used to gradually reduce the wire diameter so that the wire gradually reaches the target diameter; during the drawing process, nitrogen coolant is used to cool the wire to ensure that the surface temperature of the wire is maintained at 50°C to 100°C during the drawing process, and the wire drawing rate is controlled at 0.1 to 1.0 m / s to obtain the required diameter range of 0.2 to 1.5 mm; After drawing, the steel wire is annealed at a temperature ranging from 550°C to 650°C for 30 to 90 minutes. During the annealing process, nitrogen or argon protective atmosphere is used. After annealing, the cooling rate is controlled within 10°C / minute. During the wire drawing and annealing process, laser diameter gauges and online sensors are used to ensure that the wire diameter is maintained at ±0.05 mm in each process.

7. The process for processing a soft steel wire rope with enhanced durability according to claim 5, characterized in that: In step S2, the coating is completed by a multi-layer spraying process, and the specific steps are as follows: The high-adhesion polymer inner coating is made of polyvinyl alcohol or polystyrene material, with a coating thickness of 3 to 8 microns, and is cured at a temperature of 50° C. to 100° C. for 10 to 15 minutes after coating; The self-repairing polymer midcoat is a composite material of polyurethane or epoxy resin and self-repairing microcapsules, with a coating thickness of 5 to 15 microns and a microcapsule particle size of 50 to 200 nanometers. After coating, it is cured at a temperature of 60°C to 120°C for 10 to 20 minutes; The ceramic nano-composite outer coating is formed by compounding nano-particles of aluminum nitride or aluminum oxide with a sol matrix, with a coating thickness of 10 to 30 microns, a curing temperature of 150 to 200° C., and a curing time of 15 to 30 minutes.

8. The process for processing a soft steel wire rope with enhanced durability according to claim 5, characterized in that: In the step S3, the annealing treatment temperature is 550°C to 650°C, the treatment time is 60 to 120 minutes, the annealing process adopts uniform heating and cooling methods, and uses nitrogen or argon as a protective atmosphere; the tempering treatment temperature is 180°C to 220°C, the tempering time is 30 to 60 minutes, and the tempering process uses a hot air circulation furnace. The surface hardness after tempering is 45 to 55HRC.

9. The process for processing a soft steel wire rope with enhanced durability according to claim 5, characterized in that: In step S4, the coating method of the composite lubricant is melt spraying or electrostatic spraying, and the ratio of the lubricant is: 2 to 6 parts of ultra-high molecular weight polyethylene; 1 to 3 parts of polytetrafluoroethylene; 0.5 to 2 parts of nano-lubricating particles, wherein the nano-particles are nano-aluminum oxide or nano-silicon nitride, and the particle size range is 20 to 100 nanometers; during the coating process, the spraying pressure is controlled at 1.5 to 3.0 MPa, the coating speed is 2 to 5 meters per minute, and the coating thickness is 5 to 15 microns.

10. The process for processing a soft steel wire rope with enhanced durability according to claim 5, characterized in that: In the step S5, the curing temperature range after coating is 150°C to 250°C, the curing time is 30 to 60 minutes, the curing process adopts oven or infrared radiation heating, and naturally cools to room temperature after curing, and the cooling rate is 5°C to 15°C / minute; the surface coating uniformity of the soft steel wire rope should be not less than 95%, the surface adhesion conforms to ISO2409 standard, and the coating thickness difference is less than plus or minus 2 microns to ensure the quality stability of the finished product.

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