Stainless steel textile nozzle hard coating deplating method capable of protecting angle hole size
By combining laser-induced plating and chemical stripping with fine grinding, the problems of poor coating quality and substrate damage during the removal of coatings from textile nozzles have been solved. This has enabled efficient and low-cost surface treatment of textile nozzles, ensuring the stability of angle hole size and surface finish.
Patent Information
- Application Number
- CN202511805500.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-03
- Publication Date
- 2026-02-10
AI Technical Summary
Existing technologies for removing coatings from textile nozzle surfaces suffer from problems such as poor coating quality, high production costs, severe substrate damage, and difficulty in controlling dimensional accuracy, especially in high-speed airflow and abrasive environments, which affect textile production efficiency.
A composite process of laser-induced chemical stripping and fine grinding is adopted. Microcracks are prepared on the surface of stainless steel textile nozzles, and the chemical stripping process is precisely controlled by temperature gradient regulation and ultrasonic oscillation. Polishing and grinding are then performed to protect the angular hole size and surface finish.
It effectively shortens the stripping cycle, reduces stripping solution waste, lowers production costs, improves the production efficiency of textile nozzle surface coating, and ensures the stability of angle hole size and surface quality.
Smart Images
Figure CN121496409A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of surface coating protection, and particularly relates to a hard coating stripping method for protecting the size of an angle hole of a stainless steel textile nozzle. BACKGROUND
[0002] The textile nozzle is a core component of the air jet loom, and the main principle is to provide the weft with flying power in the weaving process by spraying compressed air. The textile nozzle has been widely used in the industry because it greatly improves the traditional textile production efficiency. However, the surface of the angle hole of the textile nozzle is prone to wear in the high-speed airflow environment containing oil stains and the textile working condition of continuous wear with the weft, which causes the change of the hole diameter, affects the airflow driving efficiency, and seriously affects the production efficiency of the textile production line. Existing research has confirmed that the use of gas deposition technology to prepare a hard film layer (such as DLC, CrN) with high hardness and wear resistance on the surface of the textile nozzle can greatly improve the wear of the angle hole of the textile nozzle.
[0003] At present, the main gas deposition technologies applied are physical vapor deposition technology (PVD) and plasma enhanced chemical vapor deposition technology (PECVD). However, these gas deposition technologies have the characteristics of long vacuum preparation process time, high process complexity, high furnace cavity maintenance cleanliness requirement, etc., which inevitably produces coating products that do not meet the quality requirements. For example, sample ablation caused by the "arc striking" phenomenon during process execution, and coating quality problems such as film layer cracking caused by excessive stress, sample scratching of the rotating shaft, etc., resulting in a substantial increase in production cost. Therefore, in order to reduce the production cost of enterprises, people often use mechanical grinding and polishing (sandblasting) or chemical stripping to restore the surface of the textile nozzle. However, if the traditional mechanical polishing and sandblasting method is used to remove the coating on the surface of the textile nozzle, the coating removal amount cannot be precisely controlled, the batch removal process is difficult to control, and the metal substrate is easily damaged, which directly leads to the scrap of the textile nozzle. However, the chemical stripping method can well avoid the above problems, but the traditional stripping method can easily corrode the surface of the metal substrate, resulting in the size of the angle hole region of the textile nozzle being out of tolerance, and the metal substrate being oxidized, which greatly reduces the surface finish of the textile nozzle. Therefore, in view of the need for stripping the hard coating on the surface of the textile nozzle, a new coating stripping method that does not damage the size of the angle hole and does not reduce the surface finish is urgently needed. SUMMARY
[0004] The present application aims at the deficiencies in the prior art, and uses a composite process of laser induction + chemical stripping + fine grinding system to finely restore the surface quality of the substrate material, greatly reduces the problems of local angle hole size out of tolerance and surface finish reduction of the textile nozzle, ensures the surface quality of the stripped substrate of the textile nozzle and protects the deformation of the special angle hole size, effectively improves the production efficiency of the surface coating of the textile nozzle, and improves the actual production efficiency.
[0005] In order to achieve the above object, the present application provides a method for removing hard coating from a stainless steel textile nozzle with an angle hole, comprising the following steps: S1, using a femtosecond laser to prepare microcracks on the surface of the stainless steel textile nozzle with hard coating, the depth of the microcracks being 2-17 μm; S2, placing the stainless steel textile nozzle with microcracks into an alkaline chemical solution, and removing the hard coating in a gradient region of high temperature-middle temperature-low temperature under the assistance of ultrasonic oscillation; the ultrasonic frequency of the ultrasonic oscillation being 20-40 kHz; the high temperature being 60-70 °C, and the removal time being 0.5-2 h; the middle temperature being 50-60 °C, and the removal time being 0.5-1 h; and the low temperature being 40-50 °C, and the removal time being 0.5-1 h; S3, placing the stainless steel textile nozzle after the coating removal into an oxide layer removal solution for a period of time, and then placing it into an antioxidant solution for a period of time; S4, polishing and grinding the stainless steel textile nozzle after the soaking, and cleaning it to obtain a stainless steel textile nozzle with a smooth surface and unchanged angle hole size.
[0006] Preferably, in step S1, the hard coating is composed of a primer layer and a surface layer; the primer layer is pure chromium or chromium-based alloy; the surface layer comprises a CrN coating, a CrAlN coating, a CrTiAlN coating or a DLC coating; and the thickness of the hard coating is 3-20 μm.
[0007] Preferably, in step S1, the hole diameter of the stainless steel textile nozzle is 1-5 mm, and the drilling angle is 5-90°.
[0008] Preferably, in step S1, during the preparation of the microcracks by the femtosecond laser, the wavelength is 355-532 nm, the pulse width is 10-50 μs, the scanning speed is 100-300 mm / s, and the light spot overlap rate is 30-50%.
[0009] Preferably, in step S2, the alkaline chemical solution comprises 5-10 wt% sodium hydroxide, 10-30 wt% sodium carbonate, 0.1-3 wt% sodium citrate and 0.1-3 wt% wetting agent, and the rest is deionized water.
[0010] Preferably, the pH value of the alkaline chemical solution is 11-13.
[0011] Preferably, in step S3, the oxide layer removal solution comprises 5-10 wt% oxalic acid and 90-95 wt% deionized water.
[0012] Preferably, the stainless steel textile nozzle is immersed in the deoxidation solution for 5 to 20 minutes and in the antioxidant solution for 8 to 15 minutes.
[0013] Preferably, in step S4, the polishing and grinding process is performed at a frequency of 30Hz to 50Hz and a polishing time of 30min to 120min; in the cleaning process, deionization cleaning is performed first, followed by ultrasonic cleaning.
[0014] Preferably, the abrasive used for polishing and grinding is a resin abrasive with resin as a binder and alumina particles encapsulated, and 0.1% to 5% lubricant and 0.1% to 3% brightener are added to the polishing liquid.
[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention addresses the problems of long stripping cycles, high costs of hazardous waste treatment of chemical reagents, safety hazards of some strong acid reagents, easy corrosion of the substrate, and easy damage to the surface quality of materials, leading to reduced or inaccurate angle and dimensional accuracy of stainless steel textile nozzles. It designs a systematic stripping process of "laser induction + chemical stripping + fine grinding", which not only shortens the stripping cycle of stainless steel textile nozzles, but also reduces the waste of stripping solution and protects the size and surface quality of the angle holes to a greater extent.
[0016] This invention utilizes a femtosecond laser to create microcracks on the surface of a stainless steel textile nozzle, breaking down the hard coating to achieve surface segmentation. The process parameters are precisely controllable, resulting in high processing efficiency. The numerous micron-level microcrack networks provide reaction channels for the chemical stripping solution to enter the coating, increasing the area of the chemical reaction zone between the hard coating and the stripping solution. Compared to a single chemical stripping method without pretreatment, this microcrack treatment solves the problem of excessively long stripping times and pilot production cycles caused by poor coating quality.
[0017] This invention fully utilizes the stripping efficiency of the chemical stripping solution by setting high-medium-low temperature zones during the chemical stripping process and combining a temperature gradient control mechanism with ultrasonic oscillation technology. After ultrasonic rinsing in the high-medium temperature zone, the residual hard coating thickness is approximately at the nanometer level. This allows for precise control of the hard coating removal rate, avoiding excessive corrosion of the stainless steel substrate by the stripping solution, reducing waste of the stripping solution, and lowering the cost of hazardous waste disposal of chemical reaction reagents and pharmaceuticals for enterprises.
[0018] This invention employs a systematic stainless steel textile nozzle stripping process, emphasizing the synergistic effect between each step compared to traditional single chemical stripping and physical removal processes. Leveraging the high efficiency of chemical stripping and the advantages of fine physical polishing, the process parameters are coordinated across each step. This increases the removal rate of the hard coating while further restoring the surface quality of the stainless steel substrate, more effectively protecting the dimensional parameters of the angle holes, reducing material waste in the textile nozzle substrate, and effectively improving cost control and production efficiency of textile nozzle surface coatings in the textile industry. Attached Figure Description
[0019] Figure 1 A process flow diagram of the hard coating stripping process for stainless steel textile nozzles with protective angle hole size provided by the present invention.
[0020] Figure 2 The images shown are optical views of a stainless steel textile nozzle before and after stripping in Embodiment 1 of the present invention, wherein (a) is the image before stripping and (b) is the image after stripping.
[0021] Figure 3 The images shown are optical views of the stainless steel textile nozzle before and after stripping in Embodiment 2 of the present invention, wherein (a) is the image before stripping and (b) is the image after stripping.
[0022] Figure 4 The image shows the surface roughness measurement results of the stainless steel textile nozzle before and after deplating in Embodiment 2 of the present invention. Detailed Implementation
[0023] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0024] A method for removing hard coatings from stainless steel textile nozzles that protect the angular aperture size is proposed, comprising the following steps: S1. Microcracks are prepared on the surface of a stainless steel textile nozzle coated with a hard coating using a femtosecond laser. The depth of the microcracks is preferably 2μm to 17μm, for example, 2μm, 5μm, 7μm, 10μm, 15μm, or 17μm. Specifically, in step S1, the material of the stainless steel textile nozzle includes, but is not limited to, various types of stainless steel such as 304, 316, and 316L. There are no restrictions here. The aperture of the stainless steel textile nozzle is 1mm to 5mm, and the drilling angle is 5° to 90°. The hard coating plated on it consists of a base layer and a top layer. The base layer is pure chromium or a chromium-based alloy, and the top layer includes, but is not limited to, CrN coating, CrAlN coating, CrTiAlN coating, and DLC coating. The thickness of the hard coating (base layer + top layer) is preferably 3μm to 20μm, for example, it can be 3μm, 5μm, 7μm, 10μm, 12μm, 15μm, 17μm, or 20μm.
[0025] Specifically, in step S1, during the fabrication of microcracks using a femtosecond laser, the wavelength is preferably 355nm to 532nm, for example, 355nm, 400nm, 425nm, 450nm, 475nm, 500nm, or 532nm; the pulse width is preferably 10μs to 50μs, for example, 10μs, 20μs, 30μs, 40μs, or 50μs; the scanning speed is preferably 100mm / s to 300mm / s, for example, 100mm / s, 150mm / s, 200mm / s, 250mm / s, or 300mm / s; and the spot overlap rate is preferably 30% to 50%, for example, 30%, 40%, or 50%.
[0026] S2. Place the micro-cracked stainless steel textile nozzle into an alkaline chemical solution. Under the assistance of ultrasonic oscillation, perform hard coating stripping sequentially according to the gradient regions of high temperature, medium temperature, and low temperature. The ultrasonic frequency of the ultrasonic oscillation is preferably 20KHz to 40KHz, for example, 20KHz, 30KHz, or 40KHz; the high temperature is preferably 60℃ to 70℃, for example, 60℃, 65℃, or 70℃, and the stripping time is preferably 0.5h to 2h, for example, 0.5h, 1h, 1.5h, or 2h; the medium temperature is preferably 50℃ to 60℃, for example, 50℃, 55℃, or 60℃, and the stripping time is preferably 0.5h to 1h, for example, 0.5h, 0.7h, or 1h; the low temperature is preferably 40℃ to 50℃, for example, 40℃, 45℃, or 50℃, and the stripping time is preferably 0.5h to 1h, for example, 0.5h, 0.7h, or 1h. Specifically, in step S2, the strategy of combining temperature gradient control mechanism with ultrasonic oscillation for chemical stripping is as follows: when stripping in the high-temperature zone, the ultrasonic oscillation frequency is high, resulting in high efficiency of chemical stripping; in the medium and low-temperature zones, the ultrasonic oscillation frequency is reduced accordingly to slow down the stripping efficiency and prevent excessive damage to the angle orifice of the stainless steel textile nozzle; by matching temperature gradient control with ultrasonic oscillation frequency, the stripping efficiency of the chemical stripping solution is fully utilized. After ultrasonic rinsing in the high-to-medium temperature zone, the thickness of the residual hard coating is approximately at the nanometer level. The removal rate of the hard coating is precisely controlled, avoiding the problem of excessive corrosion of the stainless steel substrate by the stripping solution and reducing the waste of the stripping solution.
[0027] Specifically, in step S2, the stainless steel textile nozzle containing microcracks is placed in a plastic container containing an alkaline chemical solution. The coating in the small-angle hole area is stripped by ultrasonic vibration and temperature gradient control. The alkaline chemical solution contains 5wt% to 10wt% sodium hydroxide, 10wt% to 30wt% corrosion inhibitor (sodium carbonate), 0.1wt% to 3wt% activator (sodium citrate), 0.1wt% to 3wt% wetting agent, and the remainder is deionized water. The pH value of the alkaline chemical solution is 11 to 13.
[0028] S3. After the coating has been removed, the stainless steel textile nozzle is immersed in the deoxidation solution for a period of time, and then immersed in the antioxidation solution for a period of time. Specifically, in step S3, the stainless steel textile nozzle is placed in a special deoxidation solution composed of 5wt% to 10wt% oxalic acid and 90wt% to 95wt% deionized water. The oxide layer on the surface of the small-angle hole area of the textile nozzle is removed by soaking for 5min to 20min. Then, the stainless steel textile nozzle is soaked in an antioxidant solution for preferably 8min to 15min, for example, 8min, 10min, 12min, or 15min, to prevent secondary oxidation.
[0029] S4. Polish, grind and clean the soaked stainless steel textile nozzle to obtain a stainless steel textile nozzle with a smooth surface and no change in angle orifice size. Specifically, in step S4, during the polishing and grinding process, a stainless steel textile nozzle with a smooth surface and no change in angle orifice size is obtained by coordinating and controlling the abrasive and polishing parameters. The polishing abrasive is a resin abrasive with resin as a binder and alumina particles encapsulated. The abrasive size is 1mm to 3mm. 0.1% to 5% lubricant and 0.1% to 3% brightener are added to the polishing liquid. The frequency is 30Hz to 50Hz. The polishing time is preferably 30min to 120min, for example, 30min, 50min, 70min, 90min, or 120min.
[0030] Specifically, steps S1-S4 above should be performed sequentially. After each step is completed, rinse with deionized water before proceeding to the next step. The interval between each step should be between 1 minute and 20 minutes.
[0031] The present invention will be further described below with reference to the embodiments.
[0032] Example 1 In this embodiment, the substrate material for the stripping process is a textile nozzle with a CrAlN coating deposited on a 304 stainless steel surface. Specifically, the nozzle's angle orifice size is 1mm in diameter and 5° in drilling angle. The specific implementation steps are as follows: Step 1: Using a femtosecond laser generator, microcracks are prepared on the surface of a 304 stainless steel textile nozzle with a CrAlN coating of 3μm thickness. The number of textile needles is 800. Using a femtosecond laser generator, the process parameters are set as follows: wavelength 355nm, pulse width 10μs, scanning speed 300mm / s, spot overlap rate 30%, and microcracks with a depth of 2μm are prepared.
[0033] Step 2: Weigh out the alkaline chemical solution according to the following proportions: 5 wt% sodium hydroxide, 10 wt% corrosion inhibitor (sodium carbonate), 0.1 wt% activator (sodium citrate), 0.1 wt% wetting agent, and the remainder is deionized water. Maintain the pH value of the solution within the range of 11. Prepare the solution in a 5L plastic container and then heat it in three zones: high-temperature zone to 70°C, stripping time 0.5 hours, ultrasonic frequency 40 kHz; medium-temperature zone to 55°C, stripping time 0.5 hours, ultrasonic frequency 30 kHz; and low-temperature zone to 45°C, stripping time 0.5 hours, ultrasonic frequency 20 kHz.
[0034] Step 3: Immerse the stainless steel textile nozzle treated in Step 2 in a special oxide layer removal solution containing 5 wt% oxalic acid and 95 wt% deionized water for 20 minutes. Then immerse it in an antioxidant solution for 8 minutes to prevent secondary oxidation.
[0035] Step 4: Place the stainless steel textile nozzle, which has been processed in steps 1, 2, and 3, into the polishing abrasive. The abrasive is a resin abrasive with resin as a binder and coated with alumina particles. The abrasive size is 1mm. Add 0.1% lubricant and 0.1% brightener to the polishing solution. The frequency is 30Hz and the polishing time is 30min. After polishing, clean the polished sample with deionized water. After the initial cleaning, clean it again with ultrasonic alcohol process. After cleaning, you can get the stripped 304 stainless steel textile nozzle.
[0036] In this embodiment, the 304 stainless steel textile nozzle undergoes deplating, as shown in... Figure 2As shown, the angle hole size of the textile nozzle is 1±0.02mm in diameter, 5°±0.05° in drilling angle, and the deformation rate before and after stripping is less than 0.1%, with excellent substrate surface quality.
[0037] Example 2 In this embodiment, the substrate material used for stripping is a textile nozzle with a DLC coating deposited on a 316L stainless steel surface. Specifically, the nozzle's angle orifice size is 3mm in diameter and 45° in drilling angle. The specific implementation steps are as follows: Step 1: Using a femtosecond laser generator, microcracks are fabricated on the surface of 1500 textile nozzles with a 7μm thick DLC coating. The process parameters are set as follows: wavelength 355nm, pulse width 10μs, scanning speed 200mm / s, spot overlap rate 40%, and microcracks with a depth of 5μm are fabricated.
[0038] Step 2: Weigh out the alkaline chemical solution according to the following proportions: 7 wt% sodium hydroxide, 20 wt% corrosion inhibitor (sodium carbonate), 1.5 wt% activator (sodium citrate), 1.6 wt% wetting agent, and the remainder is deionized water. Maintain the pH value of the solution at 12. Prepare the solution in a 5L plastic container and heat it in three zones: high temperature zone to 65℃, stripping time 1 hour, ultrasonic frequency 40KHz; medium temperature zone to 60℃, stripping time 0.8 hours, ultrasonic frequency 30KHz; and low temperature zone to 48℃, stripping time 0.8 hours, ultrasonic frequency 20KHz.
[0039] Step 3: Immerse the stainless steel textile nozzle treated in Step 2 in a special oxide layer removal solution containing 8 wt% oxalic acid and 92 wt% deionized water for 10 minutes. Then immerse it in an antioxidant solution for 12 minutes to prevent secondary oxidation.
[0040] Step 4: Place the stainless steel textile nozzle, which has been processed in steps 1, 2, and 3, into the polishing abrasive. The abrasive is a resin abrasive with resin as a binder and coated with alumina particles. The abrasive size is 23mm. Add 2% lubricant and 3% brightener to the polishing solution. The frequency is 40Hz and the polishing time is 60min. After polishing, clean the polished sample with deionized water. After the initial cleaning, clean it again with ultrasonic alcohol process. After cleaning, you can get the stripped 316L stainless steel textile nozzle.
[0041] In this embodiment, the deplating angle hole size of the textile nozzle is as follows: Figure 3 As shown, its angle hole dimensions are a diameter of 2.97±0.02mm, a drilling angle of 45°±0.05°, and a deformation rate of less than 0.1% before and after stripping. The substrate surface quality is excellent. Figure 4The surface roughness measurement results of the samples before and after stripping showed that the change in surface roughness before and after stripping was not obvious.
[0042] Example 3 This embodiment uses the same systematic stripping process as in Embodiments 1 and 2. The substrate material for stripping is a textile nozzle with a CrN coating deposited on a 316 stainless steel surface. The specific orifice size of the textile nozzle is a 5mm diameter and a 90° drilling angle. The specific implementation steps are as follows: Step 1: Using a femtosecond laser generator, microcracks are prepared on the surface of a 316 stainless steel textile nozzle with a 20μm thick CrN coating. The number of textile needles is 4000. The process parameters are set as follows: wavelength 532nm, pulse width 50μs, scanning speed 300mm / s, spot overlap rate 50%, and microcracks with a depth of 17μm are prepared.
[0043] Step 2: Weigh out the alkaline chemical solution according to the following proportions: 10 wt% sodium hydroxide, 30 wt% corrosion inhibitor (sodium carbonate), 3 wt% surfactant (sodium citrate), 3 wt% wetting agent, and the remainder is deionized water. Maintain the pH value of the solution in the range of 13. Prepare the solution in a 5L plastic container and heat it in three zones: high temperature zone to 70℃, stripping time 2 hours, ultrasonic frequency 40KHz; medium temperature zone to 60℃, stripping time 1 hour, ultrasonic frequency 30Khz; and low temperature zone to 45-50℃, stripping time 1 hour, ultrasonic frequency 25Khz.
[0044] Step 3: Immerse the stainless steel textile nozzle treated in Step 2 in a special oxide removal solution containing 10wt% oxalic acid and 90wt% deionized water for 20 minutes. Then immerse it in an antioxidant solution for 15 minutes to prevent secondary oxidation.
[0045] Step 4: Place the stainless steel textile nozzle, which has been processed in steps 1, 2, and 3, into the polishing abrasive. The abrasive is a resin abrasive with resin as a binder and coated with alumina particles. The abrasive size is 3mm. Add 5% lubricant and 3% brightener to the polishing solution. The frequency is 50Hz and the polishing time is 120min. After polishing, clean the polished sample with deionized water. After the initial cleaning, clean it again with ultrasonic alcohol process. After cleaning, you can get the stripped 304 stainless steel textile nozzle.
[0046] In this embodiment, the angle hole size of the textile nozzle for deplating is 4.97±0.03mm in diameter, 90°±0.05° in drilling angle, and less than 0.1% in deformation rate, resulting in excellent surface quality.
[0047] Comparative Example 1 This comparative example employs a stripping process combining traditional chemical stripping with systematic anti-oxidation treatment. The substrate material is the same as in Example 1: a textile nozzle with a CrAlN coating deposited on a 304 stainless steel surface. The specific nozzle orifice size is 1 mm in diameter and 5° in drilling angle. The specific implementation steps are as follows: Step 1: Weigh out the alkaline chemical solution containing 5wt% sodium hydroxide, 10wt% corrosion inhibitor (sodium carbonate), 0.1wt% activator (sodium citrate), and 0.1wt% wetting agent powder and deionized water according to the proportion. Maintain the pH value of the solution in the range of 11. Prepare the solution in a 5L plastic container. Put 800 304 stainless steel textile needles into the container. Maintain the stripping temperature at 70℃ and the stripping time at 8 hours.
[0048] Step 2: Immerse the stainless steel textile nozzle treated in Step 1 in a special oxide removal solution containing 10wt% oxalic acid and 90wt% deionized water for 20 minutes. Then immerse it in an antioxidant solution for 10 minutes to prevent secondary oxidation.
[0049] Test results: The stripping time was as long as 8 hours, the stripping efficiency was low, some areas around the angle holes were severely corroded, the area size was deformed and the surface finish was poor.
[0050] Comparative Example 2 The substrate material for this comparative example is the same as that in Example 1, which is a textile nozzle with a CrAlN coating deposited on a 304 stainless steel surface. The specific dimensions of the textile nozzle orifice are: orifice diameter 1 mm and drilling angle 5°. The specific implementation steps are as follows: Step 1: Using a femtosecond laser generator, microcracks are prepared on the surface of a 304 stainless steel textile nozzle with a CrAlN coating of 3μm thickness. The number of textile needles is 800. Using a femtosecond laser generator, the process parameters are set as follows: wavelength 355nm, pulse width 10μs, scanning speed 300mm / s, spot overlap rate 30%, and microcracks with a depth of 2μm are prepared.
[0051] Step 2: Weigh out the alkaline chemical solution according to the following proportions: 5 wt% sodium hydroxide, 10 wt% corrosion inhibitor (sodium carbonate), 0.1 wt% activator (sodium citrate), 0.1 wt% wetting agent, and the remainder is deionized water. Maintain the pH value of the solution in the range of 11. Prepare the solution in a 5L plastic container. Place the 304 stainless steel textile needle with microcracks into the container. Maintain the stripping temperature at 70℃ and the stripping time at 7 hours.
[0052] Step 3: Immerse the stainless steel textile nozzle treated in Step 2 in a special oxide layer removal solution containing 8 wt% oxalic acid and 92 wt% deionized water for 20 minutes. Then immerse it in an antioxidant solution for 10 minutes to prevent secondary oxidation.
[0053] Step 4: Place the stainless steel textile nozzle, which has been processed in steps 1, 2, and 3, into the polishing abrasive. The abrasive is a resin abrasive with resin as a binder and coated with alumina particles. The abrasive size is 1mm. Add 0.1% lubricant and 0.1% brightener to the polishing solution. The frequency is 30Hz and the polishing time is 30min. After polishing, clean the polished sample with deionized water. After the initial cleaning, clean it again with ultrasonic alcohol process. After cleaning, you can get the stripped 304 stainless steel textile nozzle.
[0054] Compared to Example 1, this comparative example did not undergo chemical stripping under temperature gradient control and ultrasonic oscillation assistance. Even though microcracks were prepared, the stripping time was still long and the stripping efficiency was low, resulting in corrosion in some areas around the angle holes.
[0055] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.
[0056] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0057] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A method for stripping a hard coating from a stainless steel textile nozzle that protects the angular aperture size, characterized in that, Includes the following steps: S1. Microcracks are prepared on the surface of a stainless steel textile nozzle coated with a hard coating using a femtosecond laser, wherein the depth of the microcracks is 2μm~17μm. S2. The micro-cracked stainless steel textile nozzle is placed in an alkaline chemical solution, and the hard coating is stripped sequentially according to the gradient regions of high temperature-medium temperature-low temperature under the assistance of ultrasonic oscillation; the ultrasonic frequency of the ultrasonic oscillation is 20KHz~40KHz; the high temperature is 60℃~70℃, and the stripping time is 0.5h~2h; the medium temperature is 50℃~60℃, and the stripping time is 0.5h~1h; the low temperature is 40℃~50℃, and the stripping time is 0.5h~1h. S3. After the coating has been removed, the stainless steel textile nozzle is immersed in the deoxidation solution for a period of time, and then immersed in the antioxidation solution for a period of time. S4. Polish, grind and clean the soaked stainless steel textile nozzle to obtain a stainless steel textile nozzle with a smooth surface and no change in angle orifice size.
2. The method for stripping the hard coating of a stainless steel textile nozzle with a protected angle hole size according to claim 1, characterized in that, In step S1, the hard coating consists of a base layer and a top layer; the base layer is pure chromium or a chromium-based alloy; the top layer includes CrN coating, CrAlN coating, CrTiAlN coating, and DLC coating. The thickness of the hard coating is 3~20μm.
3. The method for stripping the hard coating of a stainless steel textile nozzle with a protected angle hole size according to claim 1, characterized in that, In step S1, the diameter of the stainless steel textile nozzle is 1mm to 5mm, and the drilling angle is 5° to 90°.
4. The method for removing the hard coating of a stainless steel textile nozzle with a protected angle hole size according to claim 1, characterized in that, In step S1, during the microcrack fabrication process using the femtosecond laser, the wavelength is 355nm to 532nm, the pulse width is 10μs to 50μs, the scanning speed is 100mm / s to 300mm / s, and the spot overlap rate is 30% to 50%.
5. The method for removing hard coating from a stainless steel textile nozzle with protected angle hole size according to claim 1, characterized in that, In step S2, the alkaline chemical solution comprises 5wt%–10wt% sodium hydroxide, 10wt%–30wt% sodium carbonate, 0.1wt%–3wt% sodium citrate, 0.1wt%–3wt% wetting agent, and the remainder is deionized water.
6. The method for stripping the hard coating of a stainless steel textile nozzle with a protected angle hole size according to claim 5, characterized in that, The pH value of the alkaline chemical solution is 11-13.
7. The method for stripping the hard coating of a stainless steel textile nozzle with a protected angle hole size according to claim 1, characterized in that, In step S3, the deoxidation solution comprises 5wt% to 10wt% oxalic acid and 90wt% to 95wt% deionized water.
8. The method for removing the hard coating of a stainless steel textile nozzle with a protected angle hole size according to claim 1, characterized in that, In step S3, the stainless steel textile nozzle is immersed in the deoxidation solution for 5 min to 20 min; and in the antioxidation solution for 8 min to 15 min.
9. The method for stripping the hard coating of a stainless steel textile nozzle with a protected angle hole size according to claim 1, characterized in that, In step S4, the polishing and grinding process is performed at a frequency of 30Hz to 50Hz and a polishing time of 30min to 120min; in the cleaning process, deionized water is used for cleaning first, followed by ultrasonic cleaning.
10. The method for stripping the hard coating of a stainless steel textile nozzle with a protected angle hole size according to claim 1, characterized in that, The polishing abrasive is a resin abrasive with resin as a binder that encapsulates alumina particles, and the polishing liquid contains 0.1% to 5% lubricant and 0.1% to 3% brightener.