Method for spraying corrosion-resistant coating on surface of iron-based alloy

Abstract

The invention relates to the technical field of metal powder cold spraying, in particular to a method for spraying a corrosion-resistant coating on the surface of an iron-based alloy, which comprises the following steps: S1, carrying out sand blasting roughening treatment on the surface of the iron-based alloy through white corundum, and then carrying out ultrasonic cleaning and drying through acetone; s2, a gamma-aminopropyltriethoxysilane solution is sprayed to the surface of the iron-based alloy treated in the step S1, standing is conducted for 10-30 min, the iron-based alloy is put into a drying oven to be dried for 30-90 min at the temperature of 80-120 DEG C, and then the iron-based alloy is cooled to the room temperature; and S3, modified iron-based metal powder is subjected to cold spraying on the surface of the iron-based alloy treated in the step S2, and the corrosion-resistant coating is obtained. The corrosion-resistant coating obtained through the method has the advantages of being high in hardness and corrosion resistance, easy to operate and suitable for application and popularization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal powder cold spraying, in particular to a method for spraying a corrosion-resistant coating on the surface of an iron-based alloy. BACKGROUND

[0002] In order to improve the protection ability of the metal base, a coating layer needs to be formed on the surface of the metal base. Metal powder cold spraying is a technology for forming a coating layer on the surface of a metal base. Cold spraying is an effective technology for realizing the multifunctionalization of the surface of a material. The principle is to use compressed gas as an accelerating gas flow to drive 5-45 mu m powder particles to impact the substrate at a low temperature supersonic speed in a completely solid state, so that the particles are strongly plastically deformed and deposited to form a stacked layer, and the manufacturing of a three-dimensional part is completed. This technology has the characteristics of high efficiency, density and corrosion resistance, and is very suitable for flexible and complex printing environments. At present, cold spraying technology has been widely used in military and aerospace fields, and also shows wide application potential in the fields of aviation, energy and medical treatment.

[0003] In order to improve the performance of the coating layer, the metal powder is often improved in the existing cold spraying technology, for example, a layer of other metal is formed on the outer surface of the powder by electroplating method, and then ball milling is performed to complete the preparation of the powder and improve the performance of the prepared coating layer. The above technical route has a complex preparation method. Therefore, in view of the problems in the above background technology, the present application provides a spraying method and spraying powder which are simple to operate and can improve the performance of the corrosion-resistant coating. SUMMARY

[0004] The purpose of the present application is to provide a method for spraying a corrosion-resistant coating on the surface of an iron-based alloy to solve the problems in the above background technology.

[0005] To achieve the above purpose, the present application provides the following technical solution: A method for spraying a corrosion-resistant coating on the surface of an iron-based alloy, comprising the following steps: S1, roughening the surface of the iron-based alloy by sandblasting with white corundum, and then ultrasonic cleaning with acetone and drying; S2, spraying a gamma-aminopropyltriethoxysilane solution on the surface of the iron-based alloy treated in step S1, standing for 10-30 min, placing the iron-based alloy in an oven and drying at 80-120 DEG C for 30-90 min, and then cooling to room temperature; S3, cold spraying modified iron-based metal powder on the surface of the iron-based alloy treated in step S2 to obtain a corrosion-resistant coating; The specific preparation method of the modified iron-based metal powder comprises the following steps: S101, immerse the iron-based metal powder into an acetone solution for ultrasonic cleaning and filter and dry, then put the iron-based metal powder into hydrochloric acid for pickling and filter and dry; S102, disperse the iron-based metal powder treated in step S101 into a Tris-HCl buffer solution containing dopamine for continuous reaction for 7-10h; S103, filter out the iron-based metal powder reacted in step S102, wash with sufficient deionized water, and then calcine at 600-800 DEG C under a nitrogen atmosphere for 1-3h.

[0006] Further, the isopropyl alcohol and deionized water are contained in the gamma-aminopropyl triethoxysilane solution in step S2, and the mass ratio among the gamma-aminopropyl triethoxysilane, isopropyl alcohol and deionized water is 1:(50-60):(2-5).

[0007] Further, the gamma-aminopropyl triethoxysilane solution further contains acetic acid, and the pH of the gamma-aminopropyl triethoxysilane solution is 5-6.

[0008] Further, the spraying carrier gas for cold spraying in step S3 is nitrogen, the working gas pressure is 0.5-0.8MPa, and the temperature of the working gas is 300-600 DEG C.

[0009] Further, the average particle size of the iron-based metal powder in step S101 is 30-40mu m.

[0010] Further, the concentration of the hydrochloric acid in step S101 is 0.01-0.05mol / L.

[0011] Further, the concentration of the dopamine in step S102 is 20-30mg / ml, and the pH of the Tris-HCl buffer solution is 8.0-8.5.

[0012] Further, the mass ratio between the iron-based metal powder in step S101 and the Tris-HCl buffer solution in step S102 is 1:(10-15).

[0013] Compared with the prior art, the present application has the beneficial effects that: 1. In the present application, the surface of the iron-based alloy is pretreated, which can effectively improve the binding ability of the modified iron-based metal powder and the surface of the iron-based alloy, and improve the performance of the coating; 2. In the present application, the iron-based metal powder is further modified, first coated with polydopamine, and then calcined under inert gas to form a carbon layer, which improves the compatibility of the carbon layer with the pretreated surface of the iron-based alloy, and further improves the performance of the coating. 3. The modified iron-based metal powder used in the present application is easy to prepare, and the treatment of the surface of the iron-based alloy is simple, and the two are matched with each other, so that the performance of the corrosion-resistant coating can be greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 A process flowchart of the present application; Figure 2 A process flowchart for preparing the modified iron-based metal powder of the present application; Figure 3 A corrosion-resistant experiment graph of the corrosion-resistant coating prepared in Example 1 of the present application; Figure 4 A corrosion-resistant experiment graph of the corrosion-resistant coating prepared in Comparative Example 1 of the present application; Figure 5 A corrosion-resistant experiment graph of the corrosion-resistant coating prepared in Comparative Example 2 of the present application; Figure 6 A microstructure morphology graph of the corrosion-resistant coating prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0016] Please refer to Figures 1 to 6 The present application provides: Example 1 A method for spraying a corrosion-resistant coating on the surface of an iron-based alloy, comprising the following steps: S1, roughening the surface of the iron-based alloy by sandblasting with white corundum, and then ultrasonic cleaning with acetone and drying; S2, spraying a γ-aminopropyltriethoxysilane solution containing acetic acid on the surface of the iron-based alloy treated in step S1, the pH of the γ-aminopropyltriethoxysilane solution being 5.5, the γ-aminopropyltriethoxysilane solution containing isopropyl alcohol and deionized water, the mass ratio among the γ-aminopropyltriethoxysilane, isopropyl alcohol and deionized water being 1:55:3, standing for 25 min, and placing the iron-based alloy into an oven for drying at 100℃ for 45 min, and then cooling to room temperature; S3, cold spraying a modified iron-based metal powder on the surface of the iron-based alloy treated in step S2 to obtain a corrosion-resistant coating; The spraying carrier gas in step S3 is nitrogen, the working gas pressure is 0.7 MPa, the working gas temperature is 350 DEG C, the powder feeding speed is 25 g / s, and the nozzle moving speed is 10 mm / s.

[0017] The specific preparation method of the modified iron-based metal powder includes the following steps: S101, 200g of iron-based metal powder with an average particle size of 36μm is immersed in 1kg of acetone solution for ultrasonic cleaning and dried by filtration, and then the iron-based metal powder is placed in 1kg of 0.02mol / L hydrochloric acid for pickling and dried by filtration; S102, the iron-based metal powder treated in step S101 is dispersed in 2.2kg of Tris-HCl buffer solution containing dopamine with a pH of 8.5 for continuous reaction for 8h, and the concentration of dopamine is 25mg / ml; S103, the iron-based metal powder reacted in step S102 is filtered out, washed with sufficient deionized water, and then calcined at 700 DEG C for 1.6h under nitrogen atmosphere.

[0018] Example 2 A method for spraying a corrosion-resistant coating on the surface of an iron-based alloy includes the following steps: S1, the surface of the iron-based alloy is roughened by sandblasting with white corundum, and then ultrasonic cleaning is performed with acetone and dried; S2, a γ-aminopropyltriethoxysilane solution containing acetic acid is sprayed on the surface of the iron-based alloy treated in step S1, the pH of the γ-aminopropyltriethoxysilane solution is 5, the γ-aminopropyltriethoxysilane solution contains isopropyl alcohol and deionized water, the mass ratio of γ-aminopropyltriethoxysilane, isopropyl alcohol and deionized water is 1:50:2, and the iron-based alloy is placed in an oven and dried at 80 DEG C for 30min, and then cooled to room temperature; S3, the modified iron-based metal powder is cold sprayed on the surface of the iron-based alloy treated in step S2 to obtain a corrosion-resistant coating; The spraying carrier gas in step S3 is nitrogen, the working gas pressure is 0.5 MPa, the working gas temperature is 300 DEG C, the powder feeding speed is 25 g / s, and the nozzle moving speed is 10 mm / s.

[0019] The specific preparation method of the modified iron-based metal powder includes the following steps: S101, 200g of iron-based metal powder with an average particle size of 36μm is immersed in 1kg of acetone solution for ultrasonic cleaning and dried by filtration, and then the iron-based metal powder is placed in 1kg of 0.02mol / L hydrochloric acid for pickling and dried by filtration; S102, dispersing the iron-based metal powder treated in step S101 into 2 kg of a Tris-HCl buffer solution containing dopamine with a pH of 8.0 and continuously reacting for 7 h, the concentration of dopamine being 20 mg / ml; S103, filtering out the iron-based metal powder reacted in step S102, washing with sufficient deionized water, and then calcining at 600°C for 1 h under a nitrogen atmosphere.

[0020] Example 3 A method for spraying a corrosion-resistant coating on a surface of an iron-based alloy, comprising the following steps: S1, performing sandblasting roughening treatment on the surface of the iron-based alloy by white corundum, then performing ultrasonic cleaning with acetone and drying; S2, spraying a γ-aminopropyltriethoxysilane solution containing acetic acid on the surface of the iron-based alloy treated in step S1, the pH of the γ-aminopropyltriethoxysilane solution being 6, the γ-aminopropyltriethoxysilane solution containing isopropyl alcohol and deionized water, the mass ratio between the γ-aminopropyltriethoxysilane, isopropyl alcohol and deionized water being 1:60:5, standing for 30 min, placing the iron-based alloy into an oven and drying at 120°C for 90 min, and then cooling to room temperature; S3, cold spraying modified iron-based metal powder on the surface of the iron-based alloy treated in step S2 to obtain a corrosion-resistant coating; The spraying carrier gas for cold spraying in step S3 is nitrogen, the working gas pressure is 0.8 MPa, the working gas temperature is 500°C, the powder feeding speed is 25 g / s, and the nozzle moving speed is 10 mm / s.

[0021] The specific preparation method of the modified iron-based metal powder comprises the following steps: S101, ultrasonically cleaning and filtering and drying 200 g of iron-based metal powder with an average particle size of 40 μm by immersing the iron-based metal powder into 1 kg of an acetone solution, and then pickling and filtering and drying the iron-based metal powder by immersing the iron-based metal powder into 1 kg of hydrochloric acid with a concentration of 0.05 mol / L; S102, dispersing the iron-based metal powder treated in step S101 into 3 kg of a Tris-HCl buffer solution containing dopamine with a pH of 8.5 and continuously reacting for 10 h, the concentration of dopamine being 30 mg / ml; S103, filtering out the iron-based metal powder reacted in step S102, washing with sufficient deionized water, and then calcining at 800°C for 3 h under a nitrogen atmosphere.

[0022] Example 4 A method for spraying a corrosion-resistant coating on a surface of an iron-based alloy, comprising the following steps: S1, roughen the surface of the iron-based alloy by blasting with white corundum, then ultrasonic cleaning with acetone and drying; S2, spray the surface of the iron-based alloy treated in step S1 with a solution of gamma-aminopropyltriethoxysilane containing acetic acid, the pH of the solution of gamma-aminopropyltriethoxysilane being 5.5, the solution of gamma-aminopropyltriethoxysilane containing isopropyl alcohol and deionized water, the mass ratio between gamma-aminopropyltriethoxysilane, isopropyl alcohol and deionized water being 1:52:4, standing for 20 min, placing the iron-based alloy in an oven and drying at 100℃ for 60 min, then cooling to room temperature; S3, cold spraying modified iron-based metal powder on the surface of the iron-based alloy treated in step S2 to obtain a corrosion-resistant coating; The spraying carrier gas for cold spraying in step S3 is nitrogen, the working gas pressure is 0.7 MPa, the working gas temperature is 400℃, the powder feeding speed is 25 g / s, and the nozzle moving speed is 10 mm / s.

[0023] The specific preparation method of the modified iron-based metal powder comprises the following steps: S101, ultrasonic cleaning and filtering and drying 200g of iron-based metal powder with an average particle size of 38μm in 1kg of acetone solution, then pickling the iron-based metal powder in 1kg of 0.02mol / L hydrochloric acid and filtering and drying; S102, dispersing the iron-based metal powder treated in step S101 into 2.4kg of Tris-HCl buffer solution containing dopamine with a pH of 8.2 and continuously reacting for 8h, the concentration of dopamine being 25mg / ml; S103, filtering out the iron-based metal powder reacted in step S102, washing with sufficient deionized water, and calcining at 700℃ for 2h under a nitrogen atmosphere.

[0024] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the treatment step of step S2 is cancelled, and the remaining steps are the same as those of Example 1.

[0025] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the modified iron-based metal powder used in step S3 is changed to unmodified iron-based metal powder, and the remaining steps are the same as those of Example 1.

[0026] The iron-based metal powder Q245R alloy powder used in the present application is Q245R steel plate.

[0027] The hardness of the corrosion-resistant coatings prepared in Examples 1-4 and Comparative Examples 1-2 was tested, and the results are shown in Table 1 below: Table 1: Hardness test table of corrosion resistant coating prepared in Example 1-4 and Comparative Example 1-2

[0028] As can be seen from the data in Table 1, the hardness of the corrosion resistant coating formed can be effectively improved by further processing the surface of the iron-based alloy and modifying the iron-based metal powder in the present application.

[0029] According to the national standard GB 10124 "Metal material laboratory uniform corrosion immersion test method", the corrosion resistant test of the corrosion resistant coating prepared in Example 1 and Comparative Example 1-2 was carried out for 72 hours, and the test results are shown in Figures 3-5 As can be seen from the figure, the corrosion resistant effect of Example 1 is better than that of Comparative Example 1, and the corrosion trace of Comparative Example 2 is more obvious than that of Comparative Example 1.

[0030] Figure 6 is the microstructure morphology of the corrosion resistant coating in Example 1 of the present application, as can be seen from the figure, the corrosion resistant coating obtained by spraying according to the method of the present application has fewer pores, the internal organization of the dense coating is more uniform, and there are a small amount of pores on the surface, which is due to the fact that part of the gas is dissolved in the high-speed flying particles during the cold spraying process, and the gas is separated from the particles during the deformation process to form pores on the surface, while the corrosion resistant coating prepared by the cold spraying process of the present embodiment has low porosity, and the mechanical properties and corrosion resistance of the corrosion resistant coating are better.

[0031] Although the embodiments of the present application 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 application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method of applying a corrosion resistant coating to a surface of an iron-based alloy, characterized by, The method comprises the following steps: S1, roughening the surface of the iron-based alloy by sandblasting with white corundum, and then ultrasonic cleaning with acetone and drying; S2, spraying a γ-aminopropyltriethoxysilane solution on the surface of the iron-based alloy treated in step S1, standing for 10-30 min, placing the iron-based alloy in an oven for drying at 80-120℃ for 30-90 min, and then cooling to room temperature; S3, cold spraying a modified iron-based metal powder on the surface of the iron-based alloy treated in step S2 to obtain a corrosion-resistant coating; The specific preparation method of the modified iron-based metal powder comprises the following steps: S101, ultrasonic cleaning and filtering and drying the iron-based metal powder immersed in an acetone solution, and then pickling the iron-based metal powder in hydrochloric acid and filtering and drying; S102, dispersing the iron-based metal powder treated in step S101 in a Tris-HCl buffer solution containing dopamine and continuously reacting for 7-10 h; S103, filtering out the iron-based metal powder reacted in step S102, washing with sufficient deionized water, and then calcining at 600-800℃ under a nitrogen atmosphere for 1-3 h.

2. A method of applying a corrosion resistant coating to a surface of a ferrous alloy according to claim 1, characterised in that, The γ-aminopropyltriethoxysilane solution in step S2 contains isopropyl alcohol and deionized water, and the mass ratio among γ-aminopropyltriethoxysilane, isopropyl alcohol and deionized water is 1:(50-60):(2-5).

3. A method of applying a corrosion resistant coating to a surface of a ferrous alloy according to claim 1, wherein The γ-aminopropyltriethoxysilane solution also contains acetic acid, and the pH of the γ-aminopropyltriethoxysilane solution is 5-6.

4. A method of applying a corrosion resistant coating to a surface of a ferrous alloy according to claim 1, wherein The spraying carrier gas for cold spraying in step S3 is nitrogen, the working gas pressure is 0.5-0.8 MPa, and the working gas temperature is 300-600℃.

5. A method of applying a corrosion resistant coating to a surface of a ferrous alloy according to claim 1, wherein The average particle size of the iron-based metal powder in step S101 is 30-40 μm.

6. A method of applying a corrosion resistant coating to a surface of a ferrous alloy according to claim 1, wherein The concentration of hydrochloric acid in step S101 is 0.01-0.05 mol / L.

7. A method of applying a corrosion resistant coating to a surface of a ferrous alloy according to claim 1, wherein The concentration of dopamine in step S102 is 20-30 mg / ml, and the pH of the Tris-HCl buffer solution is 8.0-8.

5.

8. The method of claim 1 wherein the iron-based alloy is a steel. The mass ratio between the iron-based metal powder in step S101 and the Tris-HCl buffer solution in step S102 is 1:(10-15).

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