Lubricating anticorrosive coating with high corrosion resistance and long service life and coating method thereof

Abstract

The invention discloses a lubricating anti-corrosion coating with high corrosion resistance and long service life and a coating method thereof. The lubricating anti-corrosion coating comprises an electroplated layer, a molybdenum disulfide dry film lubricant layer and a paraffin lubricant coating, the electroplated layer, the molybdenum disulfide dry film lubricant layer and the paraffin lubricant coating are sequentially arranged from inside to outside, and the electroplated layer is arranged on the side close to a workpiece to be machined. According to the coating and the coating method, the lubricating property and the salt spray corrosion resistance of a corrosion-resisting steel bolt and nut thread pair can be effectively improved, the number of times of repeated disassembly and use is increased, and the outdoor use time is prolonged.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of anticorrosion coating, and particularly relates to a high-corrosion-resistance and long-service-life lubricating anticorrosion coating and a coating method thereof. BACKGROUND

[0002] As a commonly used material of aerospace fasteners, corrosion-resistant steel is generally used to manufacture nut, bolt and other types of fasteners. In the actual installation and use process, the nut and bolt thread pair needs to have excellent lubricating performance, so as to reduce the friction coefficient of the thread pair in the repeated disassembly process and prevent installation accidents such as seizure and skidding. In addition, the nut and bolt need to have excellent corrosion resistance in the actual use process, and can withstand harsh corrosion environments. However, the existing bolt and nut surface treatment method is generally to coat a molybdenum disulfide dry film lubricant coating. In the actual use process, the thread pair has a large friction coefficient, and installation and disassembly accidents such as seizure and skidding occur. In addition, in the actual use process, the original coating causes the corrosion resistance of the corrosion-resistant steel substrate to decrease due to thread pair rotation wear, handling bumping and the like, and corrosion problems easily occur in actual use. SUMMARY

[0003] Therefore, the application aims to provide a high-corrosion-resistance and long-service-life lubricating anticorrosion coating and a coating method thereof, so as to solve at least one technical problem in the background art.

[0004] To achieve the above-mentioned purpose, the technical scheme of the application is as follows: A high-corrosion-resistance and long-service-life lubricating anticorrosion coating comprises an electroplated layer, a molybdenum disulfide dry film lubricant layer and a paraffin lubricant coating layer. The electroplated layer, the molybdenum disulfide dry film lubricant layer and the paraffin lubricant coating layer are sequentially arranged from inside to outside, and the electroplated layer is arranged on the side close to a workpiece.

[0005] Further, the thickness of the electroplated layer is 8-15 mu m, and the electroplated metal is zinc-nickel or nickel; The thickness of the molybdenum disulfide dry film lubricant layer is 5-20 mu m; The concentration of the paraffin lubricant is 6%-10%.

[0006] The workpiece comprises a bolt or a nut; The workpiece is a bolt; The thickness of the gold rod of the electroplated layer is 10-14 mu m, the thickness of the support surface is 13-17 mu m, and the thickness of the threaded part is 8-12 mu m. The thickness of the gold rod of the molybdenum disulfide dry film lubricant coating layer is 7-13 mu m, the thickness of the support surface is 10-16 mu m, and the thickness of the threaded part is 5-11 mu m. The workpiece is a nut; The thickness of the support surface of the electroplated layer is 10-16 μm, and the thickness of the threaded part is 7-11 μm; Further, the molybdenum disulfide dry film lubricant layer comprises HD7352 paint and diluent, and the solid content of the molybdenum disulfide dry film lubricant layer is 40-50%; The mass ratio of the HD7352 paint and the diluent is 1:0.8-1.2; The diluent is butanone.

[0007] The thickness of the molybdenum disulfide dry film lubricant coating on the support surface is 5-20 μm, and the thickness of the threaded part is 5-20 μm.

[0008] Further, the paraffin lubricant coating comprises pure paraffin, polyethylene wax and trichloroethylene; The mass ratio of the pure paraffin and the polyethylene wax is 30:(1-0.5); The workpiece comprises a nut or a bolt; The workpiece is a nut, and the mass ratio of the sum of the pure paraffin and the polyethylene wax to the trichloroethylene is (15-18):100; The workpiece is a bolt, and the mass ratio of the sum of the pure paraffin and the polyethylene wax to the trichloroethylene is (6-10):100.

[0009] The coating method of the above-mentioned high-corrosion-resistance and long-service-life lubricating and anticorrosive coating comprises the following steps: S1: pretreating the workpiece; S2: electroplating nickel or forming an electroplated layer of nickel; S3: coating molybdenum disulfide dry film lubricant to form a molybdenum disulfide dry film lubricant layer after curing; S4: coating paraffin lubricant to form a paraffin lubricant coating.

[0010] Further, the pretreatment of the workpiece in step S1 comprises dry sandblasting the surface of the workpiece, adding deionized water to a cleaning tank with ultrasonic function, and completely immersing the sandblasted part in the ultrasonic cleaning, during which the part is shaken and turned over.

[0011] Further, the sand used for dry sandblasting the surface of the fastener in step S1 is corundum sand, and the size of the sand is 180-220 mesh; The sandblasting pressure for dry sandblasting the surface of the fastener is 0.5-0.6 MPa, the distance is 300-500 mm, and the time is 10-15 min; The power of the ultrasonic cleaning in step S1 is 9 kW; The time of the ultrasonic cleaning in step S1 is 8-12 min.

[0012] Further, the electroplating in step S2 includes electroplating on the outer surface and thread of the workpiece to be processed; The thickness of the electroplating layer is 8-15 microns; The temperature for solidification in step S3 is 200-220 DEG C, and the time is 1.8-2.2 hours; The thickness of the molybdenum disulfide dry film lubricant coating obtained by spraying in step S3 is 5-20 microns.

[0013] Further, the coating of the paraffin lubricant in step S4 includes mixing pure paraffin and polyethylene wax to obtain a mixture, adding the mixture into trichloroethylene, heating to 70-75 DEG C, soaking for 5-8 minutes, lifting, and draining; The mass ratio of the pure paraffin and the polyethylene wax is 30: (1-0.5).

[0014] Further, the workpiece to be processed includes a nut or a bolt; When the workpiece to be processed is a bolt, the mass ratio of the sum of the pure paraffin and the polyethylene wax to trichloroethylene is (15-18):100; When the workpiece to be processed is a nut, the mass ratio of the sum of the pure paraffin and the polyethylene wax to trichloroethylene is (6-10):100.

[0015] Compared with the prior art, the high corrosion-resistant and long-life lubricating anticorrosion coating and the coating method thereof have the following advantages: 1. The main content of the application is that the surface treatment method of the corrosion-resistant steel bolt is galvanizing nickel alloy 8-15 microns, then coating a molybdenum disulfide dry film lubricant coating 5-20 microns, and finally coating a paraffin lubricant coating. The surface treatment method of the corrosion-resistant steel nut is galvanizing nickel 8-15 microns, then coating a molybdenum disulfide dry film lubricant coating 5-20 microns, and finally coating a paraffin lubricant coating. The galvanizing nickel alloy layer of the corrosion-resistant steel bolt and the galvanizing nickel layer of the corrosion-resistant steel nut have excellent corrosion resistance, the molybdenum disulfide dry film lubricant coating has excellent lubricity, and the paraffin lubricant coating has excellent lubricating function. In the actual repeated disassembly and use process, the paraffin lubricant coating and the molybdenum disulfide dry film lubricant coating can reduce the friction coefficient of the thread pair, play a lubricating role in the repeated disassembly process, and protect the galvanizing nickel alloy layer and the galvanizing nickel layer from being worn. The galvanizing nickel alloy layer and the galvanizing nickel layer have excellent corrosion resistance, can protect the product substrate from being corroded by external corrosive media in the actual use process, and can effectively prolong the service life. The new type of lubricating anticorrosion coating composed of the galvanizing nickel alloy, the galvanizing nickel, the molybdenum disulfide coating, and the paraffin coating can effectively improve the number of repeated disassembly and the salt spray corrosion resistance of the corrosion-resistant steel bolt and nut fastener.

[0016] 2. The coating layer and coating method of this application can effectively improve the lubrication characteristics and salt spray corrosion resistance of corrosion-resistant steel bolts and nuts, and increase the number of repeated disassembly and use to more than 100 times. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of a highly corrosion-resistant, long-life lubricating and anti-corrosion coating proposed in this invention.

[0018] Figure 2 These are actual photos of the bolts and nuts after salt spray tests following Examples 3 and 4 of this invention; Figure 3 The images show the actual bolts and nuts assembled for the salt spray test following Embodiments 3 and 4 of the present invention. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] Example 1: The procedure for using corrosion-resistant steel bolts is as follows: Step 1: Dry sandblasting roughens the surface of the fasteners. The sand used is corundum sand with a size of 200 mesh. The sandblasting pressure is (0.5~0.6) MPa, the distance is (300~500) mm, and the time is (10~15) min.

[0022] Step 2: Ultrasonic water washing. The purpose of this step is to remove the corundum sand that adheres to the surface of the parts during sandblasting, especially the sand remaining in the threaded areas. Add deionized water to a cleaning tank with ultrasonic function (power of 9kW), and completely immerse the sandblasted parts in ultrasonic cleaning for (8-12) minutes, shaking and turning the parts during the process to ensure thorough cleaning.

[0023] Step 3: Zinc-nickel alloy plating. A layer of zinc-nickel alloy can be electroplated onto the surface of the part using any zinc-nickel alloy plating solution system. The thickness of the zinc-nickel alloy on the smooth rod, support surface, and threaded parts is 8-15 μm.

[0024] Step 4: Spraying a molybdenum disulfide dry film lubricant coating. A layer of molybdenum disulfide dry film lubricant coating can be sprayed onto the surface of the part by any method. The thickness of the coating on the smooth rod, support surface, and threaded parts is 5 to 20 μm.

[0025] Step 5: Apply a paraffin lubricant coating. Pure paraffin wax: polyethylene wax = 30: (1~0.5) (mass ratio). Dissolve the mixture in trichloroethylene, with a mass ratio of (15~18):100 between the mixture and trichloroethylene. Soak at 70~75℃ for 5~8 minutes, then lift and drain.

[0026] Example 2: The procedure for making corrosion-resistant steel nuts is as follows: Step 1: Dry sandblasting roughens the surface of the fasteners. The sand used is corundum sand with a size of 200 mesh. The sandblasting pressure is (0.5~0.6) MPa, the distance is (300~500) mm, and the time is (10~15) min.

[0027] Step 2: Ultrasonic water washing. The purpose of this step is to remove the corundum sand that adheres to the surface of the parts during sandblasting, especially the sand remaining in the threaded areas. Add deionized water to a cleaning tank with ultrasonic function (power of 9kW), and completely immerse the sandblasted parts in ultrasonic cleaning for (8-12) minutes, shaking and turning the parts during the process to ensure thorough cleaning.

[0028] Step 3: Nickel plating. A layer of nickel can be electroplated onto the surface of the part using any nickel plating solution system. The thickness of the plating layer on the outer surface and threads is 8–15 μm.

[0029] Step 4: Apply a molybdenum disulfide dry film lubricant coating. A layer of molybdenum disulfide dry film lubricant coating can be sprayed onto the surface of the part by any method. The thickness of the coating on the outer surface and threaded parts is 5 to 20 μm.

[0030] Step 5: Apply a paraffin lubricant coating. Pure paraffin wax: polyethylene wax = 30: (1~0.5) (mass ratio). Dissolve the mixture in trichloroethylene, with a mass ratio of (6~10):100 between the mixture and trichloroethylene. Soak at 70~75℃ for 5~8 minutes, then lift and drain.

[0031] Example 3 A self-locking nut made of 17-4PH material, specification MJ6, and a bolt made of A286 material, specification 6×14, are required to be repeatedly disassembled at least 100 times, and after the bolt and nut are assembled 100 times, they must withstand an acetic acid spray test for more than 200 hours.

[0032] Corrosion-resistant steel bolts are processed according to the following procedure: sandblasting → ultrasonic water washing → zinc-nickel alloy plating → drying → molybdenum disulfide coating → curing. Specific process parameters are as follows: Sandblasting: Corundum sand, 200 mesh size, sandblasting pressure (0.5-0.6) MPa, distance (300-500) mm, time (15 min).

[0033] Ultrasonic water washing: deionized water, time (8-10) min.

[0034] Zinc-nickel alloy plating: Zinc chloride: 70-100 g / L; Nickel chloride: 90-120 g / L; Ammonium chloride: 200-240 g / L; Boric acid: 20-30 g / L; Sodium dodecylbenzenesulfonate: 0.05 g / L. Temperature: 25℃, Current density: 1.5 A / dm³ 2 The electroplating time was 45 minutes. Metallographic analysis showed that the thickness of the zinc-nickel alloy rod was 12 μm, the thickness of the support surface was 15 μm, and the thickness of the threaded part was 10 μm.

[0035] Molybdenum disulfide dry film lubricant coating: HD7352 paint concentrate with a solid content of 45% was used, diluted with methyl ethyl ketone (MEK) at a mass ratio of 1:1. A layer of molybdenum disulfide dry film lubricant coating was sprayed onto the bolt surface. Spraying parameters were: spraying pressure 0.2-0.4 MPa, spraying distance 300 mm, and curing at 210℃ for 2 hours. Metallographic analysis showed that the molybdenum disulfide coating thickness was 9 μm on the smooth bolt surface, 13 μm on the support surface, and 8 μm on the threaded area.

[0036] Apply a paraffin lubricant coating. Pure paraffin wax: polyethylene wax = 30:1 (mass ratio). Dissolve the mixture in trichloroethylene at a mass ratio of 15:100. Immerse at 75°C for 8 minutes, then remove and drain.

[0037] Example 4 A self-locking nut made of 17-4PH material, specification MJ6, and a bolt made of A286 material, specification 6×14, are required to be repeatedly disassembled at least 100 times, and after the bolt and nut are assembled 100 times, they must withstand an acetic acid spray test for more than 200 hours.

[0038] Corrosion-resistant steel nuts are processed according to the following procedure: sandblasting → ultrasonic water washing → nickel plating → drying → dip coating with molybdenum disulfide → spray coating with molybdenum disulfide → curing. Specific process parameters are as follows: Sandblasting: Corundum sand, 200 mesh size, sandblasting pressure (0.5-0.6) MPa, distance (300-500) mm, time (15 min).

[0039] Ultrasonic water washing: deionized water, time (8-10) min.

[0040] Nickel plating: Nickel sulfate: 250-300 g / L; Sodium sulfate: 40-50 g / L; Magnesium sulfate: 30-40 g / L; Boric acid: 30-40 g / L; Sodium chloride: 15-18 g / L. Temperature: 30℃, Current density: 7 A / dm³ 2The electroplating time was 50 minutes. Metallographic analysis showed that the thickness of the nickel plating on the support surface was 13 μm and the thickness on the threaded part was 9 μm.

[0041] Dip-coating with molybdenum disulfide dry film lubricant: For nuts and similar products, a layer of molybdenum disulfide dry film lubricant is first applied to the internal threads using a dip-coating method. HD7352 paint concentrate, with a solids content of 45%, is diluted with methyl ethyl ketone (MEK) at a mass ratio of 1:2. The parts are completely immersed in the paint for 30 seconds, then lifted and drained. Pre-curing is then performed in a 150°C oven for at least 15 minutes. The parts are then immersed again for 30 seconds, lifted and drained. Finally, curing is done in a 210°C oven for 2 hours.

[0042] Molybdenum disulfide dry film lubricant coating: HD7352 paint concentrate with a solids content of 45% was used, diluted with methyl ethyl ketone (MEK) at a mass ratio of 1:1. A layer of molybdenum disulfide dry film lubricant coating was sprayed onto the bolt surface. Spraying parameters were: spraying pressure 0.2-0.4 MPa, spraying distance 300 mm, and curing at 210℃ for 2 hours. Metallographic analysis showed that the thickness of the molybdenum disulfide coating on the support surface was 9 μm, and the thickness on the threaded area was 15 μm.

[0043] Apply a paraffin lubricant coating. Pure paraffin wax: polyethylene wax = 30:0.5 (mass ratio). Dissolve the mixture in trichloroethylene at a mass ratio of 10:100. Immerse at 75°C for 7 minutes, then remove and drain.

[0044] Five bolts and five nuts were randomly selected and repeatedly disassembled 100 times. No installation problems such as seizing or slippage occurred. The repeatedly disassembled bolts and nuts were placed in a salt spray test chamber and subjected to a salt spray test according to GJB150.11, with a pH value of 3.5 and a test cycle of 200 hours. No red rust appeared on the bolts and nuts.

[0045] Example 5 The difference from Example 3 is as follows: Nickel alloy plating bath composition: Zinc chloride: 80-90 g / L; Nickel chloride: 100-120 g / L; Ammonium chloride: 205-240 g / L; Boric acid: 25-30 g / L; Sodium dodecylbenzenesulfonate: 0.08 g / L. Temperature: 20℃, Current density: 1.3 A / dm³ 2 The electroplating time was 50 minutes. Metallographic analysis showed that the thickness of the zinc-nickel alloy rod was 12 μm, the thickness of the support surface was 15 μm, and the thickness of the threaded part was 10 μm.

[0046] Provide the corresponding effect Example 6 The difference from Example 4 is as follows: Nickel alloy plating bath composition: Zinc chloride: 70-100 g / L; Nickel chloride: 90-120 g / L; Ammonium chloride: 200-240 g / L; Boric acid: 20-30 g / L; Sodium dodecylbenzenesulfonate: 0.05 g / L. Temperature: 25℃, Current density: 1.5 A / dm³ 2 The electroplating time was 45 minutes. Metallographic analysis showed that the thickness of the zinc-nickel alloy rod was 12 μm, the thickness of the support surface was 15 μm, and the thickness of the threaded part was 10 μm.

[0047] Comparative Example 1 The difference from Example 3 is that sandblasting is not performed. The coating has poor adhesion and poor wear resistance.

[0048] Comparative Example 2 Compared to Example 3, no electroplating layer was applied. With only a coating, the salt spray resistance and corrosion resistance are poor.

[0049] Comparative Example 3 The difference from Example 3 is that the thickness of the zinc-nickel alloy rod was 3 μm, the thickness of the support surface was 4 μm, and the thickness of the threaded part was 2 μm. A thinner coating results in poorer salt spray resistance.

[0050] Comparative Example 4 The difference from Example 3 is that the zinc-nickel alloy rod thickness is 22μm, the support surface thickness is 23μm, and the threaded portion thickness is 21μm. A thicker coating can easily lead to assembly interference, affecting service life.

[0051] Comparative Example 5 The difference from Example 3 is that no molybdenum disulfide dry film lubricant coating is applied. The coating has poor wear resistance.

[0052] Comparative Example 6 The difference from Example 3 is that the molybdenum disulfide dry film lubricant coating has a molybdenum disulfide coating thickness of 3 μm on the smooth rod, 5 μm on the support surface, and 2 μm on the threaded portion. The thin coating results in poor wear resistance.

[0053] Comparative Example 7 The difference from Example 3 is that no paraffin lubricant coating is applied. The coating has poor wear resistance.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A highly corrosion-resistant, long-life lubricating and anti-corrosion coating, characterized in that: It includes an electroplated layer, a molybdenum disulfide dry film lubricant layer, and a paraffin lubricant coating, which are arranged sequentially from the inside to the outside, with the electroplated layer located on the side closest to the workpiece to be processed.

2. The method for applying a high corrosion-resistant, long-life lubricating and anti-corrosion coating according to claim 1, characterized in that: The thickness of the electroplated layer is 8–15 μm, and the electroplated metal is zinc-nickel or nickel; The thickness of the molybdenum disulfide dry film lubricant layer is 5–20 μm; The concentration of paraffin lubricant is 6% to 10%.

3. The method for applying a highly corrosion-resistant, long-life lubricating and anti-corrosion coating according to claim 1, characterized in that: The molybdenum disulfide dry film lubricant layer includes HD7352 coating and diluent, and the solid content of the molybdenum disulfide dry film lubricant layer is 40-50%. The mass ratio of HD7352 coating to thinner is 1:0.8-1.2; The diluent is butanone; The thickness of the molybdenum disulfide dry film lubricant coating on the support surface is 5-20 μm, and the thickness on the threaded parts is 5-20 μm.

4. The method for applying a highly corrosion-resistant, long-life lubricating and anti-corrosion coating according to claim 1, characterized in that: Paraffin lubricant coatings include pure paraffin, polyethylene wax, and trichloroethylene; The mass ratio of pure paraffin wax to polyethylene wax is 30:(1-0.5); The workpiece to be processed includes nuts or bolts; The workpiece to be processed is a nut, and the mass ratio of the sum of pure paraffin wax and polyethylene wax to trichloroethylene is (15-18):100; The workpiece to be processed is a bolt, and the mass ratio of the sum of pure paraffin wax and polyethylene wax to trichloroethylene is (6-10):

100.

5. A method for applying a highly corrosion-resistant, long-life lubricating and anti-corrosion coating according to any one of claims 1-4, characterized in that: Includes the following steps: S1: Pre-processing of the workpiece; S2: Electroplating of nickel or forming an electroplated layer with nickel; S3: Coating with molybdenum disulfide dry film lubricant, which cures to form a molybdenum disulfide dry film lubricant layer; S4: Apply paraffin lubricant to form a paraffin lubricant coating.

6. The method for applying a highly corrosion-resistant, long-life lubricating and anti-corrosion coating according to claim 5, characterized in that: Step S1 involves pre-treating the workpiece by dry sandblasting to roughen its surface, adding deionized water to a cleaning tank with ultrasonic function, and completely immersing the sandblasted part in ultrasonic cleaning, during which the part is shaken and flipped.

7. The method for applying a highly corrosion-resistant, long-life lubricating and anti-corrosion coating according to claim 6, characterized in that: In step S1, the sand used for dry sandblasting to roughen the surface of the fastener is corundum sand with a size of 180-220 mesh. The sandblasting pressure for roughening the surface of fasteners by dry sandblasting is 0.5-0.6 MPa, the distance is 300-500 mm, and the time is 10-15 min. The power of ultrasonic cleaning in step S1 is 9kW; The ultrasonic cleaning time in step S1 is 8 to 12 minutes.

8. The method for applying a highly corrosion-resistant, long-life lubricating and anti-corrosion coating according to claim 5, characterized in that: In step S2, electroplating includes electroplating on the outer surface and threads of the workpiece. The thickness of the electroplated layer is 8–15 μm; In step S3, the curing temperature is 200-220℃, and the curing time is 1.8-2.2 hours. In step S3, the thickness of the molybdenum disulfide dry film lubricant coating sprayed onto the workpiece is 5–20 μm.

9. The method for applying a highly corrosion-resistant, long-life lubricating and anti-corrosion coating according to claim 5, characterized in that: In step S4, applying paraffin lubricant involves mixing pure paraffin and polyethylene wax to obtain a mixture, adding the mixture to trichloroethylene, heating to 70-75°C, soaking for 5-8 minutes, lifting, and draining. The mass ratio of pure paraffin wax to polyethylene wax is 30: (1 to 0.5).

10. The method for applying a highly corrosion-resistant, long-life lubricating and anti-corrosion coating according to claim 5, characterized in that: The workpiece to be processed includes nuts or bolts; The workpiece to be processed is a bolt, and the mass ratio of the sum of pure paraffin wax and polyethylene wax to trichloroethylene is (15-18):100; The workpiece to be processed is a nut, and the mass ratio of the sum of pure paraffin wax and polyethylene wax to trichloroethylene is (6-10):100.

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