Iron-based amorphous alloy suitable for marine environment and method for preparing coating based on iron-based amorphous alloy

Abstract

The invention discloses an iron-based amorphous alloy suitable for a marine environment and a method for preparing a coating based on the iron-based amorphous alloy. The chemical formula of the iron-based amorphous alloy is Fe < 35 > Ni < 20-x > Cr < 20 > Mo < 5 > B < 4 > C < 4 > P < 12 > Ce < x >, wherein the value of x ranges from 0.5 to 1.5. On the basis of the iron-based amorphous alloy, a coating formed by adopting a high velocity oxy-fuel spraying mode not only has good seawater corrosion resistance, but also has good microbial corrosion resistance; after the coating is soaked in a culture medium solution inoculated with pseudomonas aeruginosa for 14 days, the self-corrosion potential is-314 mV, the self-corrosion current density is 5.9 [mu] A cm <-2 >, the passivation interval exceeds 1200 mV, and the passivation current density is 5.1 [mu] A cm <-2 >.

Description

Technical Field

[0001] The invention relates to an iron-based amorphous alloy suitable for marine environment, and also relates to a method for preparing a coating based on the iron-based amorphous alloy. Background Art

[0002] Offshore facilities (such as oil drilling platforms, offshore wind power and nuclear power facilities), port machinery and ship equipment need to be used in the marine environment for a long time. The high salt, high humidity, oxygen-rich characteristics and microorganisms in the marine environment will induce continuous electrochemical corrosion of metal materials, leading to material failure and structural damage in the equipment, thereby significantly shortening its service life and increasing operation and maintenance costs and safety risks. Therefore, improving the corrosion resistance and service life of marine engineering equipment has become a core technical bottleneck in promoting marine construction.

[0003] Iron-based amorphous alloys rely on long-range disordered atomic structure and uniform composition characteristics, and inhibit the penetration of corrosive media by eliminating defects such as grain boundaries and dislocations. Their corrosion resistance is significantly better than that of traditional crystalline alloys. However, the cost of bulk preparation is high, and factors such as room temperature brittleness and low amorphous forming ability (GFA) restrict their engineering applications. Based on this, thermal spraying technology is used to prepare iron-based amorphous alloy coatings, which avoids the risk of brittle failure while retaining the intrinsic corrosion resistance of the material. However, for iron-based amorphous alloy coatings used in complex marine environments, in addition to being resistant to seawater corrosion, the influence of microbial corrosion must also be considered. Marine microorganisms mainly include eukaryotic microorganisms (such as fungi), prokaryotic microorganisms (such as bacteria), and acellular organisms (such as viruses). As a common aerobic bacterium in the marine environment, Pseudomonas aeruginosa will have a relatively serious impact on metal materials and equipment used in the marine environment. Therefore, high requirements are placed on the corrosion resistance of metal materials and equipment used in the marine environment to Pseudomonas aeruginosa. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide an iron-based amorphous alloy suitable for marine environment. The coating formed based on the iron-based amorphous alloy not only has good seawater corrosion resistance, but also has good microbial corrosion resistance. Another purpose of the present invention is to provide a method for preparing a coating from the above-mentioned iron-based amorphous alloy.

[0005] Technical solution: The iron-based amorphous alloy suitable for marine environment described in the present invention has the chemical formula: Fe 35 Ni 20- x Cr 20 Mo 5 B 4 C 4 P 12 Ce x ; wherein, the value of x is 0.5 to 1.5; further preferably, the value of x is 0.5 to 0.75.

[0006] Among them, iron-based amorphous alloy powder Fe 35 Ni 20-x Cr 20 Mo 5 B 4 C 4 P 12 Ce x The powder is prepared by vacuum atomization method, and the amorphous content of the powder is higher than 60%.

[0007] The method for preparing a coating based on the above-mentioned iron-based amorphous alloy is specifically as follows: using iron-based amorphous alloy powder as raw material, preparing an iron-based amorphous alloy coating on the surface of a substrate by supersonic flame spraying.

[0008] Among them, iron-based amorphous alloy powder with a particle size less than 50 μm is selected as the raw material of the thermal spray coating.

[0009] Wherein, during the supersonic flame spraying process, the air pressure is 85-95 psi, and the fuel pressure is 80-90 psi.

[0010] Wherein, during the supersonic flame spraying process: the nitrogen flow rate is 20 to 40 SLPM.

[0011] Wherein, during the supersonic flame spraying process: the powder feeding rate is 3 to 5 rpm.

[0012] Wherein, during the supersonic flame spraying process: the spraying distance is 220-240 mm, and the moving speed of the spray gun is 900-1200 mm / s.

[0013] The amorphous content of the iron-based amorphous alloy coating is greater than 70%, and the porosity is less than 1% (the present invention uses iron-based amorphous alloy powder with a particle size of 18-50 μm, and controls the heat input conditions (air pressure and fuel pressure during the spraying process) to avoid generating more oxidized powder and pores while improving the density of the coating; the coating thickness is 300-400 μm.

[0014] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: the coating formed by the iron-based amorphous alloy of the present invention and the supersonic flame spraying method has not only good seawater corrosion resistance, but also good microbial corrosion resistance; the coating is immersed in the culture medium solution inoculated with Pseudomonas aeruginosa for 14 days, and the self-corrosion potential is -314mV, and the self-corrosion current density is 5.9μA cm -2 , the passivation interval exceeds 1200mV, and the passivation current density is 5.1μAcm -2The iron-based amorphous alloy coating of the present invention can be applied to the surface of marine equipment to prevent corrosion and corrosion wear of the equipment by seawater and Pseudomonas aeruginosa, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The iron-based amorphous alloy strip Fe prepared by the present invention 35 Ni 20-x Cr 20 Mo 5 B 4 C 4 P 12 Ce x (x value is 0~1.5) X-ray diffraction pattern;

[0016] Figure 2 The iron-based amorphous alloy strip Fe prepared by the present invention 35 Ni 20-x Cr 20 Mo 5 B 4 C 4 P 12 Ce x (x ranges from 0 to 1.5) and the electrodynamic curve of 304SS after being immersed in sterile 2216E culture medium solution for 14 days;

[0017] Figure 3 The iron-based amorphous alloy strip Fe prepared by the present invention 35 Ni 20-x Cr 20 Mo 5 B 4 C 4 P 12 Ce x (x ranges from 0 to 1.5) and the potential curve of 304SS after being immersed in 2216E medium solution inoculated with Pseudomonas aeruginosa for 14 days;

[0018] Figure 4 The iron-based amorphous alloy strip Fe prepared by the present invention 35 Ni 20-x Cr 20 Mo 5 B 4 C 4 P 12 Ce x (x ranges from 0 to 1.5) Plate counts of 304SS after immersion in 2216E medium solution inoculated with Pseudomonas aeruginosa for 14 days;

[0019] Figure 5 The iron-based amorphous alloy powder Fe prepared in Example 2 35 Ni19.25 Cr 20 Mo 5 B 4 C 4 P 12 Ce 0.75 SEM images of

[0020] Figure 6 The Fe-based amorphous alloy coating Fe prepared in Example 2 35 Ni 19.25 Cr 20 Mo 5 B 4 C 4 P 12 Ce 0.75 SEM image of the cross section;

[0021] Figure 7 The X-ray diffraction diagram of the iron-based amorphous alloy strip, powder and coating with the same composition prepared in Example 2;

[0022] Figure 8 The potentiodynamic curves of the iron-based amorphous alloy coating and 304SS prepared in Example 2 and Comparative Examples 1 to 3 after being immersed in the 2216E culture medium solution inoculated with Pseudomonas aeruginosa for 14 days;

[0023] Fig. 9 Schematic diagram of the biofilm of the iron-based amorphous alloy coating and 304SS prepared in Example 2 after being immersed in the 2216E culture medium solution inoculated with Pseudomonas aeruginosa for 14 days. DETAILED DESCRIPTION

[0024] Example 1

[0025] The iron-based amorphous alloy strip Fe 35 Ni 19.25 Cr 20 Mo 5 B 4 C 4 P 12 Ce 0.75 The preparation method comprises the following steps:

[0026] (1) Calculate the required mass of each raw material of the alloy according to the atomic percentage (stoichiometric ratio) of the required component (element) and weigh it using a five-digit electronic balance with a weighing error of ±0.5 mg;

[0027] (2) placing the alloy raw material in a quartz crucible, using a vacuum induction melting method, melting in an argon atmosphere for 20 minutes to ensure the uniformity of the alloy composition, and naturally cooling to room temperature to obtain a master alloy ingot;

[0028] (3) The prepared master alloy ingot was crushed into small pieces and loaded into a quartz tube with a nozzle diameter of 0.8 mm. The master alloy was melted in an argon atmosphere by a single-roller rapid quenching method and the melt was sprayed onto a high-speed rotating copper roller to obtain an iron-based amorphous alloy strip Fe. 35 Ni 19.25 Cr 20 Mo 5 B 4 C 4 P 12 Ce 0.75 , the copper roller linear speed is about 30m / s.

[0029] Preparation of Fe-based amorphous alloy strip Fe based on the method of Example 1 35 Ni 19.5 Cr 20 Mo 5 B 4 C 4 P 12 Ce 0.5 、Fe-based amorphous alloy strip Fe 35 Ni 19.25 Cr 20 Mo 5 B 4 C 4 P 12 Ce 0.75 、Fe-based amorphous alloy strip Fe 35 Ni 19 Cr 20 Mo 5 B 4 C 4 P 12 Ce 1 、Fe-based amorphous alloy strip Fe 35 Ni 18.5 Cr 20 Mo 5 B 4 C 4 P 12 Ce 1.5 、Fe-based amorphous alloy strip Fe 35 Ni 18.75 Cr 20 Mo 5 B 4 C 4 P 12 Ce 1.25 and Fe-based amorphous alloy strip Fe 35 Ni 20 Cr 20 Mo 5 B 4 C 4 P 12 .

[0030] Figure 1 The iron-based amorphous alloy strip Fe prepared by the present invention 35 Ni 20-x Cr 20 Mo 5 B 4 C 4 P 12 Ce x (x value is 0~1.5) X-ray diffraction pattern; from Figure 1 It can be seen that the strips of all components show a broad diffuse diffraction peak, which shows a complete amorphous structure, and also shows that the doping of Ce element does not affect the amorphous forming ability of the alloy.

[0031] Figure 2 The iron-based amorphous alloy strip Fe prepared by the present invention 35 Ni 20-x Cr 20 Mo 5 B 4 C 4 P 12 Ce x (x ranges from 0 to 1.5) and the potentiodynamic polarization curve of 304SS strips in sterile 2216E culture medium environment. The composition of the culture medium is shown in Table 1. Figure 2 It can be seen that the self-corrosion potentials of the component strips (x values ​​are 0, 0.5, 0.75, 1.0, 1.25, and 1.5) with 304SS and 316SS are -361mV, -302mV, -291mV, -377mV, -412mV, -438mV, -468mV, and -401mV, respectively, and the self-corrosion current density is 1.8μA cm -2 , 1.2μA cm -2 , 0.8μA cm -2 , 2.4μA cm -2 、3.7μA cm -2 , 5.2μA cm -2 , 4.9μA cm -2 and 3.5 μA cm -2 , the passivation current density is 2.3 μA cm -2 , 1.3μA cm -2 , 1.1μA cm -2 , 2.8μA cm -2 、4.1μAcm -2 , 5.6μA cm -2 、7.8μA cm -2 and 5.8 μA cm -2It can be found that the iron-based amorphous alloy strip with x = 0.75 exhibits a wider passivation range, the lowest passivation current density, self-corrosion current density and passivation current density, thus showing more excellent corrosion resistance.

[0032] Figure 3 The iron-based amorphous alloy strip Fe prepared by the present invention 35 Ni 20-x Cr 20 Mo 5 B 4 C 4 P 12 Ce x (x ranges from 0 to 1.5) and 304SS strips were inoculated with Pseudomonas aeruginosa (initial bacterial concentration was 10 6 Potentiodynamic polarization curves after immersion in 2216E culture medium solution with 10 cells / ml for 14 days. Figure 3 It can be seen that the self-corrosion potentials of the component strips (x values ​​are 0, 0.5, 0.75, 1.0, 1.25, and 1.5) with 304SS and 316SS are -381mV, -269mV, -273mV, -344mV, -319mV, -423mV, -477mV, and -423mV, respectively, and the self-corrosion current density is 5.7μA cm -2 , 2.3μA cm -2 , 0.9μA cm -2 、3.4μAcm -2 , 4.5μA cm -2 , 5.2μA cm -2 , 5.3μA cm -2 and 4.7 μA cm -2 , the passivation current density is 8.7 μA cm -2 , 5.6μA cm -2 、4.7μAcm -2 , 9.4μA cm -2 , 12.7μA cm -2 , 12.6μA cm -2 , 11.2μA cm -2 and 7.5 μA cm -2 It can be found that the iron-based amorphous alloy strip with x = 0.75 exhibits a wider passivation range, the lowest passivation current density, self-corrosion current density and passivation current density, thus showing more excellent corrosion resistance.

[0033] Figure 4 The iron-based amorphous alloy strip Fe prepared by the present invention 35 Ni 20-x Cr 20Mo 5 B 4 C 4 P 12 Ce x (x ranges from 0 to 1.5) and 304SS strips (304 stainless steel strips) inoculated with Pseudomonas aeruginosa (initial bacterial concentration is 10 6 Schematic diagram of plate counting after immersion in 2216E culture medium solution with 10 cells / ml for 14 days. Figure 4 It can be found from the comparison that with the increase of Ce element, the number of colonies decreases to a certain extent; when x=0.75, the number of Pseudomonas aeruginosa colonies is the least, showing good antibacterial performance; when the Ce element continues to increase, the number of colonies increases again. This is because the increase of Ce element deteriorates the corrosion resistance of the strip to a certain extent, making bacteria more inclined to attach to its surface. Compared with 304SS, the number of colonies on the coated plate is less when x=0.75, and its antibacterial performance is better than that of 304SS.

[0034] Example 2

[0035] The iron-based amorphous alloy coating Fe 35 Ni 19.25 Cr 20 Mo 5 B 4 C 4 P 12 Ce 0.75 The preparation method comprises the following steps

[0036] (1) Calculate the required mass of each raw material of the alloy according to the atomic percentage (stoichiometric ratio) of the required component (element) and weigh it using a five-digit electronic balance with a weighing error of ±0.5 mg;

[0037] (2) placing the alloy raw material in a quartz crucible, using a vacuum induction melting method, melting in an argon atmosphere for 20 minutes to ensure the uniformity of the alloy composition, and naturally cooling to room temperature to obtain a master alloy ingot;

[0038] (3) The master alloy ingot is crushed and placed in a gas atomization powder making furnace, and under the protection of argon gas, an iron-based amorphous alloy powder with an amorphous content of more than 60% is obtained by gas atomization. 35 Ni 19.25 Cr 20 Mo 5 B 4 C 4 P 12 Ce 0.75 , selecting powder with a particle size less than 50 μm as the raw material for thermal spray coating;

[0039] (4) Using the supersonic flame spraying method, the iron-based amorphous alloy powder prepared in step (3) is used to prepare an iron-based amorphous alloy coating on the surface of the 304SS substrate. The process parameters of the supersonic flame spraying process are: air pressure of 90 psi, fuel pressure of 80 psi, nitrogen flow rate of 40 SLPM, powder feeding rate of 3 rpm, spraying distance of 220 mm, and spray gun moving speed of 1000 mm / s.

[0040] Figure 5 The iron-based amorphous alloy powder Fe prepared in Example 2 35 Ni 19.25 Cr 20 Mo 5 B 4 C 4 P 12 Ce 0.75 Scanning electron microscope image of Figure 5 It can be seen that the powder is nearly spherical, with a particle size distribution below 50 μm and good fluidity.

[0041] Figure 6 The Fe-based amorphous alloy coating Fe prepared in Example 2 35 Ni 19.25 Cr 20 Mo 5 B 4 C 4 P 12 Ce 0.75 A cross-sectional SEM image of the Figure 6 It can be seen that the thickness of the amorphous coating is about 360 μm; the porosity of the coating was evaluated using Image-Pro Plus software, and the porosity of the coating was about 0.64%.

[0042] Figure 7 The X-ray diffraction diagram of the iron-based amorphous alloy powder and the iron-based amorphous alloy coating prepared in Example 2. Figure 7 It can be seen that both the powder and the coating present a broad diffuse diffraction peak and a small amount of crystallization peak; through the curve estimation, it can be obtained that the amorphous content of the powder and the coating is 62.8% and 75.2%, respectively.

[0043] Figure 8 The iron-based amorphous alloy coating prepared in Example 2 and the coatings of Comparative Examples 1 to 3 were inoculated with Pseudomonas aeruginosa (initial bacterial concentration was 10 6 Potentiodynamic polarization curves after immersion in 2216E culture medium solution with 10 cells / ml for 14 days. From the curves, it can be seen that the self-corrosion potentials of the coating in Example 2 and the coatings in Comparative Examples 1 to 3 are -314 mV, -429 mV, -417 mV and -398 mV, respectively, and the self-corrosion current densities are 5.9 μA cm -2、22.1μAcm -2 , 16.9μA cm -2 and 8.4 μA cm -2 , while the passivation current density of the coating in Example 2 is 5.1 μA cm -2 , and the coatings in comparative examples 2 and 3 were 8.7 μA cm -2 、11.2μAcm -2 (Comparative Example 1 has no obvious passivation interval), which is better than 304SS. In addition, when the potential reaches 0.4mV, 304SS shows obvious pitting, the corrosion current density rises sharply, and the corrosion resistance deteriorates, while the coating of Example 2 and the coatings of Comparative Examples 2 and 3 show a wider passivation interval (up to 1200mV). In summary, the coating of Example 2 has the lowest corrosion potential and corrosion current density, showing the most excellent resistance to Pseudomonas aeruginosa corrosion.

[0044] Fig. 9 The iron-based amorphous alloy coating prepared in Example 2 was inoculated with Pseudomonas aeruginosa (initial bacterial concentration was 10 6 The biofilm image was taken by laser confocal scanning microscopy after immersion in 2216E culture medium solution with 10 cells / ml for 14 days. Fig. 9 It can be seen that the biofilm thickness on the surface of the iron-based amorphous alloy coating is 15-18 mm, while the biofilm thickness on the surface of 304SS is 22-26 mm. It can be found that Pseudomonas aeruginosa is more inclined to attach to the surface of 304SS and form a thicker biofilm, while the iron-based amorphous alloy coating has a more stable passivation film and better resistance to Pseudomonas aeruginosa corrosion. The thickness of its surface biofilm is reduced by about 1 / 3 compared with 304SS, showing good resistance to Pseudomonas aeruginosa corrosion.

[0045] In addition, the hardness of the cross section of the iron-based amorphous alloy coating prepared in Example 2 was tested using a Vickers microhardness tester, with a load of 500 g and an action time of 15 s, and 10 areas were randomly selected for measurement. The results showed that the hardness of the iron-based amorphous alloy coating was about 600 HV.

[0046] Comparative Example 1

[0047] based on Figure 1 It can be seen that the Fe-based amorphous alloy strip Fe 35 Ni 20 Cr 20 Mo 5 B 4 C 4 P 12 It also presents a completely amorphous structure, and the amorphous content of the strip is also greater than 90%. Its corrosion resistance to Pseudomonas aeruginosa is better than that of 304 stainless steel, but its antibacterial performance is equivalent to that of 304 stainless steel.

[0048] Iron-based amorphous alloy coating Fe 35 Ni 20 Cr 20 Mo 5 B 4 C 4 P 12 The preparation method comprises the following steps

[0049] (1) Calculate the required mass of each raw material of the alloy according to the atomic percentage (stoichiometric ratio) of the required component (element) and weigh it using a five-digit electronic balance with a weighing error of ±0.5 mg;

[0050] (2) placing the alloy raw material in a quartz crucible, using a vacuum induction melting method, melting in an argon atmosphere for 20 minutes to ensure the uniformity of the alloy composition, and naturally cooling to room temperature to obtain a master alloy ingot;

[0051] (3) The master alloy ingot is crushed and placed in a gas atomization powder making furnace, and under the protection of argon gas, an iron-based amorphous alloy powder with an amorphous content of more than 60% is obtained by gas atomization. 35 Ni 20 Cr 20 Mo 5 B 4 C 4 P 12 , selecting powder with a particle size less than 50 μm as the raw material for thermal spray coating;

[0052] (4) Using the supersonic flame spraying method, the iron-based amorphous alloy powder prepared in step (3) is used to prepare an iron-based amorphous alloy coating Fe on the surface of the 304SS substrate. 35 Ni 20 Cr 20 Mo 5 B 4 C 4 P 12 The process parameters of the supersonic flame spraying process are: air pressure of 85 psi, fuel pressure of 82 psi, nitrogen flow rate of 25 SLPM, hydrogen flow rate of 35 SLPM, powder feeding rate of 3 rpm, spraying distance of 240 mm, and spray gun moving speed of 1000 mm / s.

[0053] The X-ray diffraction pattern of the amorphous coating in Comparative Example 1 shows an amorphous structure. The amorphous content of the coating under this process is 85%. The porosity of the coating is evaluated by a scanning electron microscope image of the cross section, and the porosity of the coating is about 3.80%.

[0054] Comparative Example 2

[0055] Iron-based amorphous alloy coating Fe 35 Ni20 Cr 20 Mo 5 B 4 C 4 P 12 The preparation method comprises the following steps

[0056] (1) Calculate the required mass of each raw material of the alloy according to the atomic percentage (stoichiometric ratio) of the required component (element) and weigh it using a five-digit electronic balance with a weighing error of ±0.5 mg;

[0057] (2) placing the alloy raw material in a quartz crucible, using a vacuum induction melting method, melting in an argon atmosphere for 20 minutes to ensure the uniformity of the alloy composition, and naturally cooling to room temperature to obtain a master alloy ingot;

[0058] (3) The master alloy ingot is crushed and placed in a gas atomization powder making furnace, and under the protection of argon gas, an iron-based amorphous alloy powder with an amorphous content of more than 60% is obtained by gas atomization. 35 Ni 20 Cr 20 Mo 5 B 4 C 4 P 12 , selecting powder with a particle size less than 50 μm as the raw material for thermal spray coating;

[0059] (4) Plasma spraying technology was used to prepare iron-based amorphous alloy on the surface of 304 stainless steel substrate. The process parameters were: spraying power 42 kW, argon flow rate 85 L / min, hydrogen flow rate 7.3 L / min, powder feeding rate 25 g / min, spraying distance 12 mm, and spray gun moving speed 1000 mm / s.

[0060] The X-ray diffraction pattern of the amorphous coating in Comparative Example 2 shows an oxide phase. The amorphous content of the coating under this process is 60%. The porosity of the coating is evaluated by a scanning electron microscope image of the cross section, and the porosity of the coating is about 3.25%.

[0061] Comparative Example 3

[0062] Iron-based amorphous alloy coating Fe 35 Ni 19.25 Cr 20 Mo 5 B 4 C 4 P 12 Ce 0.75 The preparation method comprises the following steps

[0063] (1) Calculate the required mass of each raw material of the alloy according to the atomic percentage (stoichiometric ratio) of the required component (element) and weigh it using a five-digit electronic balance with a weighing error of ±0.5 mg;

[0064] (2) placing the alloy raw material in a quartz crucible, using a vacuum induction melting method, melting in an argon atmosphere for 20 minutes to ensure the uniformity of the alloy composition, and naturally cooling to room temperature to obtain a master alloy ingot;

[0065] (3) The master alloy ingot is crushed and placed in a gas atomization powder making furnace, and under the protection of argon gas, an iron-based amorphous alloy powder with an amorphous content of more than 60% is obtained by gas atomization. 35 Ni 19.25 Cr 20 Mo 5 B 4 C 4 P 12 Ce 0.75 , selecting powder with a particle size less than 50 μm as the raw material for thermal spray coating;

[0066] (4) Plasma spraying technology was used to prepare iron-based amorphous alloy on the surface of 304 stainless steel substrate. The process parameters were: spraying power 45 kW, argon flow rate 80 L / min, hydrogen flow rate 7.5 L / min, powder feeding rate 25 g / min, spraying distance 15 mm, and spray gun moving speed 1000 mm / s.

[0067] The amorphous content of the coating under this process is 87%. The porosity of the coating is evaluated by scanning electron microscopy of the cross section, and the porosity of the coating is about 2.40%.

[0068] The iron-based amorphous alloy coating prepared in Example 2 and the coatings of Comparative Examples 1 to 3 were inoculated with Pseudomonas aeruginosa (initial bacterial concentration was 10 6 After being immersed in 2216E culture medium solution of 10 cells / ml for 14 days, the corrosion and wear test in the culture medium solution of Pseudomonas aeruginosa was carried out on the friction and wear instrument. The load was 30N, the frequency was 5Hz, and the friction pair material was Φ12.7mm Si 3 N 4 The wear volumes of the coatings prepared in Example 2 and Comparative Examples 1 to 3 and 304SS were 1.44×10 -3 mm 3 , 2.89×10 -3 mm 3 , 2.46×10 -3 mm 3 , 1.85×10 -3 mm 3 and 3.23×10 -3 mm 3The wear rates are 2.40×10 - 6 mm 3 N -1 m -1 ,4.71×10 -6 mm 3 N -1 m -1 4.15×10 -6 mm 3 N -1 m -1 ,3.52×10 -6 mm 3 N -1 m -1 and 5.38×10 -6 mm 3 N - 1 m -1 Therefore, the wear volume and wear rate of the iron-based amorphous coating prepared in Example 2 are the smallest, indicating that it has excellent corrosion and wear resistance in the Pseudomonas aeruginosa environment.

[0069] Table 1 shows the composition of the 2216E liquid culture medium solution used in the present invention. - The concentration is equivalent to 3.5wt.% NaCl solution, but it also contains other acid ions (such as SO 4 2- 、NO3 - and BO 3 3- etc.), thereby showing a more complex acidic environment to simulate the real seawater environment.

[0070] Table 1

[0071]

[0072]

Claims

1. An iron-based amorphous alloy suitable for marine environment, characterized in that: Its chemical formula is:Fe 35 Ni 20- x Cr 20 Mo5B4C4P 12 Ce x ; Wherein, the value of x is 0.5~1.

5.

2. The iron-based amorphous alloy according to claim 1, characterized in that: The value of x is 0.5 to 0.

75.

3. The iron-based amorphous alloy according to claim 1, characterized in that: Iron-based amorphous alloy powderFe 35 Ni 20- x Cr 20 Mo5B4C4P 12 Ce x The powder is prepared by vacuum atomization method, and the amorphous content of the powder is higher than 60%.

4. A method for preparing a coating according to claim 3, characterized in that: Specifically, iron-based amorphous alloy powder is used as raw material, and an iron-based amorphous alloy coating is prepared on the surface of a substrate by supersonic flame spraying.

5. The method according to claim 4, characterized in that: Iron-based amorphous alloy powder with a particle size less than 50 μm is selected as the raw material of the thermal spray coating.

6. The method according to claim 4, characterized in that: During the supersonic flame spraying process, the air pressure is 85-95 psi, and the fuel pressure is 80-90 psi.

7. The method according to claim 4, characterized in that: During the supersonic flame spraying process, the nitrogen flow rate is 20-40 SLPM.

8. The method according to claim 4, characterized in that: During the supersonic flame spraying process: the powder feeding rate is 3-5 rpm.

9. The method according to claim 4, characterized in that: During the supersonic flame spraying process, the spraying distance is 220-240 mm, and the moving speed of the spray gun is 900-1200 mm / s.

10. The method according to claim 4, characterized in that: The amorphous content of the iron-based amorphous alloy coating is greater than 70%, and the porosity is less than 1%; the thickness of the coating is 300-400 μm.

Images