Composite corrosion-resistant film layer on surface of steel blade and preparation method of composite corrosion-resistant film layer

Abstract

The invention discloses a composite corrosion-resistant film layer on the surface of a steel blade and a preparation method of the composite corrosion-resistant film layer, the composite corrosion-resistant film layer is formed by compositing and overlapping a passive film layer and a hydrophobic film layer, the passive film layer is located on the surface of a steel blade matrix, and the hydrophobic film layer is located on the surface of the passive film layer. The preparation method of the composite corrosion-resistant film layer comprises the following steps: pretreatment: removing oil stains on the surface of the steel blade matrix; interface passivation is conducted, specifically, the surface of the steel blade base body is subjected to passivation treatment at the room temperature in a chemical passivation mode, and a passivation film layer is formed; hydrophobic treatment, wherein a hydrophobic film layer is formed on the surface of the passive film layer in a spraying mode at the room temperature; and curing treatment: curing the hydrophobic film layer formed in the step 3 at room temperature. The preparation method is simple, batch processing can be achieved, and the steel blade corrosion-resistant film layer with the good hydrophobic effect, high corrosion resistance and high-temperature stability is finally obtained.

Description

Technical Field

[0001] This invention belongs to the field of surface treatment technology, specifically relating to a composite corrosion-resistant film layer on the surface of steel blades and an efficient method for preparing the composite corrosion-resistant film layer. Background Technology

[0002] Steel compressor blades (made of 1Cr17Ni2) are core components of aero-engines, subjected to the combined effects of high temperature, high pressure, and high-cycle fatigue loads over long periods. Therefore, surface treatment is necessary for steel blades. Current steel surface protection technology mainly employs electrochemical passivation to form a passivation film. Its protective mechanism relies primarily on the physicochemical properties of the passivation film to achieve physical barrier and protection.

[0003] However, although passivation film is a simple and efficient protective technology, it is a single-layer protection system with obvious limitations: on the one hand, its protective effect is concentrated on the corrosion protection of the material surface; on the other hand, it is prone to lattice reconstruction under high temperature conditions, which leads to performance degradation. In addition, the coupling effect of high pressure fluid impact and cyclic load can easily lead to the peeling of the passivation film layer from the substrate interface and the propagation of microcracks, making it difficult to meet the long-term protection requirements under extreme conditions. Summary of the Invention

[0004] The present invention aims to provide a composite corrosion-resistant film layer on the surface of steel blades and its preparation method, thereby optimizing the existing protection methods for steel blades, improving the high-temperature corrosion resistance of steel blades, and providing a composite corrosion-resistant film layer with uniform appearance, no cracks, no peeling, no holes, no blistering, and good water-repellent effect, high corrosion resistance and high-temperature stability, thus achieving long-term protection.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A composite corrosion-resistant film layer on the surface of a steel blade, comprising: A passivation film layer is located on the surface of the steel blade substrate; A hydrophobic film layer is located on the surface of the passivation film layer.

[0006] Alternatively, the total thickness of the passivation film and the hydrophobic film is 2 μm to 7 μm.

[0007] Alternatively, the wetting angle of the composite corrosion-resistant film is 100° to 180°.

[0008] The method for preparing the above-mentioned composite corrosion-resistant film on the surface of steel blades includes: Step 1: Pretreatment to remove oil stains from the surface of the steel blade substrate; Step 2, interface passivation: The surface of the steel blade substrate is passivated by chemical passivation at room temperature to form a passivation film. Step 3: Hydrophobic treatment, a hydrophobic film is formed on the surface of the passivation film by spraying at room temperature; Step four, curing treatment, curing the hydrophobic film layer formed in step three at room temperature.

[0009] Alternatively, in step two, the passivation solution used for chemical passivation is a nitric acid solution.

[0010] Furthermore, the nitric acid solution has a density of 1.42. It is prepared by mixing nitric acid and water, and the concentration of the nitric acid solution is 300. ~500 .

[0011] Alternatively, in step three, the passivation film obtained in step two is first cleaned and dried, and then a water-repellent material is sprayed using a spray gun. The nozzle diameter of the spray gun is 0.3mm to 1.5mm, the pressure of the compressed air used for spraying is 0.2MPa to 0.6MPa, and the spraying distance is 10±5cm.

[0012] Alternatively, the hydrophobic material is designated LD-4380, a high-performance, high-temperature resistant hydrophobic agent. It should be noted that LD-4380 is a commercially available functional coating made from composite silicon oxide nanomaterials.

[0013] Alternatively, in step four, the hydrophobic film can be cured by allowing it to stand at room temperature under dry and clean conditions.

[0014] It should be noted that the room temperature in this invention refers to the local temperature when preparing the composite corrosion-resistant film layer on the surface of the steel blade. Generally, the room temperature range is 10℃ to 25℃, and the room temperature in step two (interface passivation), step three (hydrophobic treatment) and step four (curing treatment) is the same temperature.

[0015] Compared with existing technologies, this invention adds a hydrophobic film layer to the surface of a conventional passivation film layer by spraying a hydrophobic film with specific parameters. This results in a composite corrosion-resistant film layer on the surface of steel blades that is uniform in appearance and texture, without cracks, peeling, pores, or blistering. The composite film layer of this invention exhibits good hydrophobicity, with a wetting angle of 100°–180°, effectively isolating corrosive media from contact with the film surface. Compared to a single film layer, the hydrophobicity of the composite film layer significantly reduces the erosion of the film layer by corrosive media, improving the corrosion resistance of the steel blades. Furthermore, the hydrophobic film layer remains stable after prolonged baking at 400°C, demonstrating excellent high-temperature stability and achieving long-term protection.

[0016] In this invention, the hydrophobic film and the passivation film are not simply superimposed, but ultimately form a composite film. Compared with a single hydrophobic film and a single passivation film, the corrosion resistance is greatly improved, the high temperature stability is also greatly improved, the bonding with the substrate is stable, and the composite film is free from defects such as cracks, pores and peeling.

[0017] The composite corrosion-resistant film of the present invention has a thickness of 2μm to 7μm, and has a good and stable bonding state with the metal substrate surface. The production and processing flow and process are simple and can be easily mass-produced. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the anti-corrosion effect of the composite corrosion-resistant film layer in this invention; Figure 2 Microscopic image of the composite corrosion-resistant film prepared in this invention; Figure 3 Photo of product packaging for hydrophobic materials; In the figure: 1. Hydrophobic film, 2. Passivation film, 3. Composite film, 4. Steel blade substrate. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments, but it should not be construed as limiting the scope of the subject matter of the present invention to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0020] like Figure 1 As shown, this invention provides a high-performance composite film layer, composed of a passivation film layer 2 and a hydrophobic film layer 1 stacked together. The passivation film layer 2 is located on the surface of the steel blade substrate 4, and the hydrophobic film layer 1 is located on the surface of the passivation film layer 2. Based on the above film layer composition, this invention first generates a passivation film on the clean surface of the steel blade substrate 4, then sprays a hydrophobic film onto the passivation film surface, and after curing, obtains a composite film layer with good hydrophobicity. This composite film layer can effectively isolate the steel blade substrate 4 from substances such as oxygen, water, and sodium chloride in a corrosive environment, providing long-term protection.

[0021] Specifically, the following steps can be used to prepare a composite corrosion-resistant film on the surface of steel blades: Step (1), Pretreatment: Wipe the steel blades with an organic solvent (e.g., acetone) to keep the blade surface oil-free; Step (2), interface passivation: a dense passivation film 2 is constructed using a room temperature passivation solution with a specific ratio; Step (3), precise control of spraying parameters: a multi-parameter coordinated spraying process is used to form a hydrophobic film layer 1; Step (4), adaptive curing under specific conditions: the composite film layer 3 structure is stabilized in a dry and clean environment at room temperature (i.e., a specific environment), that is, the process by which the hydrophobic film layer 1 automatically adjusts itself to undergo composite behavior with the passivation film layer 2.

[0022] In step (2), the specific component of the room temperature passivation solution is nitric acid (density ρ = 1.42). The remainder is water, and the concentration of the passivation solution is 300%. ~500 ; In step (3), the controlled spraying parameters include the nozzle diameter of the spray gun, the pressure of the compressed air for spraying, and the spraying distance. The nozzle diameter of the spray gun is 0.3mm to 1.5mm, the pressure of the compressed air for spraying is 0.2MPa to 0.6MPa, and the spraying distance is (10±5)cm. The spray gun is moved at a constant speed to spray the surface to be sprayed 4 to 8 times.

[0023] Example 1: A method for preparing a composite corrosion-resistant film on the surface of a steel blade includes the following steps: (1) Surface degreasing treatment: Use clean degreased cotton soaked in acetone to wipe the leaf blade in one direction 3 times. After visually inspecting the surface for any water stains, place it in a dust-free air to air dry naturally for 5 minutes before use. (2) Chemical passivation treatment: The passivation solution consists of nitric acid (density ρ = 1.42). ) and water, after preparation, a concentration of 300 is obtained. The passivation solution was used to place the steel blade (material 1Cr17Ni2) in the passivation solution at room temperature for 30 min, then the steel blade was rinsed in clean water at room temperature for 0.5 min, and finally left to stand to obtain passivation film layer 2. (3) Water-repellent film spraying: LD-4380 is used as the water-repellent material (e.g. Figure 3 Using a spray gun, the passivated, cleaned and dried blade surface is uniformly sprayed 4 to 8 times under the conditions of a spray gun nozzle diameter of 0.3 mm, a compressed air pressure of 0.2 MPa, and a spraying distance of 5 cm to obtain a hydrophobic film layer 1. (4) Curing of film layer: Place the sprayed blade in a clean and dust-free environment and let it stand at room temperature for 48 hours.

[0024] The composite film layer 3 prepared according to the above scheme was visually inspected and observed under an optical microscope. The film layer showed a continuous and dense surface morphology, and no interface failure characteristics such as cracking or peeling were observed. At the same time, the performance of the composite film layer prepared by this method was tested, including hydrophobic effect, corrosion resistance and high temperature stability: it was found that water droplets formed spherical water droplets on the surface of the test piece after the hydrophobic film layer was qualified and cured, and the water droplets would automatically flow down after tilting the sample. After drying, there were no water marks on the blade surface, and the wetting angle reached 105°. When it was placed in a 3% sodium chloride solution for 8 hours, no corrosion points appeared on the surface of the blade film layer. After long-term baking at 400℃ and cooling, the hydrophobic film layer was found to be stable, and the composite film layer has good high temperature stability.

[0025] Example 2: A method for preparing a composite corrosion-resistant film on the surface of a steel blade includes the following steps: (1) Surface degreasing treatment: Use clean degreased cotton soaked in acetone to wipe the leaf blade in one direction 3 times. After visually inspecting the surface for any water stains, place it in a dust-free air to air dry naturally for 5 minutes before use. (2) Chemical passivation treatment: The passivation solution consists of nitric acid (density ρ = 1.42). ) and water, after preparation, a concentration of 400 is obtained. The passivation solution was used to place the steel blade (material 1Cr17Ni2) in the passivation solution at room temperature for 45 min, then the steel blade was rinsed in clean water at room temperature for 0.7 min, and finally allowed to stand to obtain the passivation film layer 2. (3) Water-repellent film spraying: LD-4380 is used as the water-repellent material (e.g. Figure 3 Using a spray gun, the passivated, cleaned and dried blade surface is uniformly sprayed 4 to 8 times under the conditions of a spray gun nozzle diameter of 1.0 mm, a compressed air pressure of 0.4 MPa, and a spraying distance of 10 cm to obtain a hydrophobic film layer 1. (4) Curing of film layer: Place the sprayed blade in a clean and dust-free environment and let it stand at room temperature for 48 hours.

[0026] The composite film prepared by this method has a wetting angle of 115° and also has good hydrophobicity, corrosion resistance and high temperature stability.

[0027] Example 3: A method for preparing a composite corrosion-resistant film on the surface of a steel blade includes the following steps: (1) Surface degreasing treatment: Use clean degreased cotton soaked in acetone to wipe the leaf blade in one direction 3 times. After visually inspecting the surface for any water stains, place it in a dust-free air to air dry naturally for 5 minutes before use. (2) Chemical passivation treatment: The passivation solution consists of nitric acid (density ρ = 1.42). ) and water, after preparation, a concentration of 500 is obtained. The passivation solution was used to place the steel blade (material 1Cr17Ni2) in the passivation solution at room temperature for 60 min, then the steel blade was rinsed in clean water at room temperature for 1 min, and finally left to stand to obtain the passivation film layer 2. (3) Water-repellent film spraying: LD-4380 is used as the water-repellent material (e.g. Figure 3 Using a spray gun, the passivated, cleaned and dried blade surface is uniformly sprayed 4 to 8 times under the conditions of a spray gun nozzle diameter of 1.5 mm, a compressed air pressure of 0.6 MPa, and a spraying distance of 15 cm to obtain a hydrophobic film layer 1. (4) Curing of film layer: Place the sprayed blade in a clean and dust-free environment and let it stand at room temperature for 48 hours.

[0028] The composite film prepared by this method has a wetting angle of 108° and also has good hydrophobicity, corrosion resistance and high temperature stability.

[0029] Contents not described in detail in this specification are prior art known to those skilled in the art. Although illustrative specific embodiments of the invention have been described above to facilitate understanding by those skilled in the art, it should be understood that the invention is not limited to the scope of the specific embodiments. Various modifications are readily apparent to those skilled in the art as long as they fall within the spirit and scope of the invention as defined and determined by the appended claims, and all inventions utilizing the concept of this invention are protected.

Claims

1. A composite corrosion-resistant film layer on the surface of a steel blade, characterized in that, include: Passivation film (2) is located on the surface of the steel blade substrate (4); Hydrophobic film layer (1) is located on the surface of passivation film layer (2).

2. The composite corrosion-resistant film layer on the surface of a steel blade according to claim 1, characterized in that: The total thickness of the passivation film (2) and the hydrophobic film (1) is 2 μm to 7 μm.

3. The composite corrosion-resistant film layer on the surface of a steel blade according to claim 1, characterized in that: The wetting angle of the composite corrosion-resistant film is 100° to 180°.

4. The method for preparing the composite corrosion-resistant film on the surface of a steel blade as described in claim 1 or 2, characterized in that, include: Step 1, pretreatment, to remove oil stains from the surface of the steel blade substrate (4); Step 2, interface passivation: At room temperature, the surface of the steel blade substrate (4) is passivated by chemical passivation to form a passivation film (2). Step 3, hydrophobic treatment: a hydrophobic film layer (1) is formed on the surface of the passivation film layer (2) by spraying at room temperature. Step 4, curing treatment, curing the hydrophobic film layer (1) formed in step 3 at room temperature.

5. The method for preparing a composite corrosion-resistant film on the surface of a steel blade according to claim 4, characterized in that: In step two, the passivation solution used for chemical passivation is a nitric acid solution.

6. The method for preparing a composite corrosion-resistant film on the surface of a steel blade according to claim 5, characterized in that: The nitric acid solution has a density of 1.

42. It is prepared by mixing nitric acid and water, and the concentration of the nitric acid solution is 300. ~500 .

7. The method for preparing a composite corrosion-resistant film on the surface of a steel blade according to claim 4, characterized in that: In step three, the passivation film layer (2) obtained in step two is first cleaned and dried, and then the hydrophobic material is sprayed using a spray gun. The nozzle diameter of the spray gun is 0.3mm to 1.5mm, the pressure of the compressed air used for spraying is 0.2MPa to 0.6MPa, and the spraying distance is 10±5cm.

8. The method for preparing a composite corrosion-resistant film on the surface of a steel blade according to claim 7, characterized in that: The grade of the hydrophobic material is LD-4380 high-performance high-temperature resistant hydrophobic agent.

9. The method for preparing a composite corrosion-resistant film on the surface of a steel blade according to claim 4, characterized in that: In step four, the hydrophobic film layer (1) is cured by standing at room temperature under dry and clean conditions.

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