A method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction kettle

Abstract

This invention discloses a method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction vessel, belonging to the technical field of wear-resistant and corrosion-resistant material preparation. The zirconium-based amorphous alloy of this invention contains, by mass percentage, 40-45% Zr, 10-14% Ti, 10-15% Cu, 8-10% Ni, 20-25% Be, and unavoidable impurities. The method for preparing the wear-resistant and corrosion-resistant zirconium-based amorphous coating includes the following steps: S1: Pre-treating the substrate; S2: Treating the substrate using electrical pulse technology; S3: Preparing the wear-resistant and corrosion-resistant zirconium-based amorphous coating using plasma spraying technology. This invention's method of simultaneously applying electrical pulses to the substrate during atmospheric plasma spraying ensures that the zirconium-based amorphous coating on the reaction vessel surface has high bonding strength, resulting in a zirconium-based amorphous coating material with advantages such as high hardness, good wear resistance, and good corrosion resistance, exhibiting excellent mechanical properties.

Description

Technical Field

[0001] This invention relates to a method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction vessel, belonging to the field of wear-resistant and corrosion-resistant material preparation technology. Background Technology

[0002] With the increasing demand for high-purity substances, high-temperature and high-pressure reactors are used in their synthesis. Due to the need to withstand high temperatures and pressures, the selection of equipment materials is particularly important. During the reaction process of high-purity substances, the reactor walls experience severe corrosion and wear. Therefore, the development of new reactor materials that are resistant to strong corrosion and wear, and offer high cost-effectiveness is urgently needed. Due to the unique atomic structure of zirconium-based amorphous materials, they possess advantages such as high strength, high elastic limit, and high corrosion resistance, and are widely used in wear-resistant and corrosion-resistant equipment.

[0003] To improve the performance of wear-resistant steel castings, Chinese invention patent CN 111349927 A discloses a composite coating for wear-resistant and corrosion-resistant surfaces of mechanical parts and its preparation method. The composite coating includes a transition layer and a functional layer. The transition layer is made of pure chromium, titanium, or nickel and is located between the functional layer and the workpiece surface to improve the surface performance of mechanical parts. Chinese invention patent CN 111349927 A relates to a corrosion-resistant and wear-resistant coating and its cold spray preparation method, addressing the problem of easy corrosion and severe wear of aluminum coatings on metal parts. The coating successfully prepared using the cold spray process has high bonding strength with the metal part surface, and the coating structure is dense with low porosity, which can be used to improve the wear resistance, corrosion resistance, and high-temperature resistance of the base material. Due to the curved shape of the inner wall of the reactor, traditional spraying processes result in low bonding strength of the sprayed coating, making it prone to peeling off. Therefore, the development of new spraying processes is urgently needed.

[0004] In summary, the above patents primarily focus on zirconium alloys, improving their wear and corrosion resistance by adding other elements, and developing methods for preparing various corrosion-resistant and wear-resistant coatings. However, they lack information on the corrosion and wear mechanisms of zirconium-based amorphous materials under different extreme environments, as well as the design processes for corrosion-resistant and wear-resistant coatings under such conditions. Addressing the shortcomings of existing coating technologies for high-temperature and high-pressure reactors, this paper proposes developing new methods for preparing zirconium-based amorphous coatings for reactors. This aims to improve the wear and corrosion resistance of zirconium-based amorphous coating materials, extend the service life of high-temperature and high-pressure reactors, adapt to corrosion and wear conditions in extreme environments, and further expand the application scope of zirconium-based amorphous materials. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention provides a method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reactor. This invention employs a substrate pretreatment and pulsed current treatment of the substrate, followed by plasma spraying to prepare the wear-resistant and corrosion-resistant zirconium-based amorphous coating. This process ensures sufficient bonding strength of the zirconium-based amorphous coating on the reactor surface, resulting in a zirconium-based amorphous coating material with high hardness, good wear resistance, good corrosion resistance, and excellent mechanical properties.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction vessel, comprising an electrical pulse treatment during plasma spraying, including the following steps:

[0008] (1) First, the substrate is pretreated, including surface grinding, sandblasting and ultrasonic cleaning, and then cleaned and dried with alcohol.

[0009] (2) The substrate is treated with AC pulse technology. When the pulse treatment temperature is above 200℃, the pulse is stopped; when the substrate temperature is below 150℃, the pulse is started.

[0010] (3) A wear-resistant and corrosion-resistant zirconium-based amorphous coating was prepared by plasma spraying technology. The zirconium-based amorphous alloy composition and its mass percentage were: 40-45% Zr, 10-14% Ti, 10-15% Cu, 8-10% Ni, 20-25% Be and unavoidable impurities.

[0011] Preferably, the substrate of the present invention is a high-temperature and high-pressure reactor material, including 316 stainless steel, titanium alloy, and zirconium alloy.

[0012] Preferably, the pretreatment of the substrate in step (1) of the present invention refers to grinding the surface of the substrate by mechanical grinding, with a roughness Ra < 0.5, or directly removing surface contaminants by corundum sandblasting, with a surface roughness of Ra 8.0-10.0 after treatment, and then cleaning and drying with alcohol.

[0013] Preferably, the pulse processing conditions in step (2) of the present invention are: pulse width of 1-30 μs, pulse interval of 50-100 μs, and pulse current density of 200-1000 A / mm. 2 .

[0014] Preferably, in step (3) of the present invention: the spraying process is as follows: current 550-650A, voltage 40-50V, argon flow rate 80-90L / min, hydrogen flow rate 1-2L / min, spraying distance 80-100mm, linear velocity 500-700mm / s, coating thickness 200-300μm; argon is used as an inert atmosphere protective gas, and the argon flow rate is 6-8L / min.

[0015] Preferably, in step (3) of the present invention: the diameter of the zirconium-based amorphous coating powder is 10-55 μm; the thickness of the zirconium-based amorphous coating is 250-350 μm.

[0016] The principle of this invention:

[0017] Because the inner wall of the reactor is curved, traditional spraying processes result in low coating strength and easy peeling. Pre-treatment of the reactor substrate (sandblasting, grinding, etc.) to create a certain surface roughness is beneficial for powder adhesion. Since the atoms in zirconium-based amorphous materials exhibit a short-range ordered and long-range disordered structure, applying a pulsed current can relax the amorphous structure, breaking the short-range ordered structure and making the atomic arrangement more disordered. This leads to more intense atomic diffusion between the amorphous material and the reactor substrate, creating a diffusion effect and forming an interface. Applying a pulsed current to the reactor substrate raises the substrate temperature, reducing the temperature difference between the zirconium-based amorphous powder and the substrate during plasma spraying, resulting in better matching of the wettability of the two materials. Ultimately, a zirconium-based amorphous coating material with high hardness, good wear resistance, and corrosion resistance, as well as excellent mechanical properties, is obtained.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] (1) The method described in this invention reduces the problem of insufficient interfacial bonding strength. The main reason for interfacial cracking of the coating is that the insufficient bonding strength between the substrate and the coating material leads to delamination when the stress perpendicular to the coating surface is applied to the coating surface. Since the surface of the reactor is curved, there is a large internal stress inside the coating, which is very easy to fall off under corrosion and wear conditions, thus losing its protective function for the reactor. This invention sets up a substrate surface pretreatment process, which increases the surface roughness of the substrate by mechanical grinding and sandblasting, greatly increasing the adhesion area of ​​the powder on the substrate surface; at the same time, the application of electric pulse treatment has a preheating effect on the substrate, reducing the temperature difference between the sprayed powder and the substrate, and allowing the amorphous coating to adhere better to the substrate.

[0020] (2) Compared with conventional amorphous spraying production processes, this invention has two characteristics. First, a pulsed current is continuously applied to the substrate during the spraying process. On the one hand, this causes more intense atomic activity in the sprayed powder material, breaking the ordered structure and forming a disordered amorphous coating. On the other hand, the pulsed current causes interfacial elements to diffuse into each other, forming a structure with a hardness between that of zirconium-based amorphous materials and the substrate. This effectively facilitates the transition of material properties, preventing defects and low bonding strength caused by material property mismatch. Simultaneously, the electrical pulse effect effectively releases residual stress caused by spraying, preventing cracking and other problems caused by residual stress during application. Second, plasma spraying technology is used, preventing crystallization of the amorphous alloy during the spraying process and meeting performance control requirements. This invention has the advantages of simple operation and ease of implementation for enterprises. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the zirconium-based amorphous coating combined with 316L in the embodiment.

[0022] Figure 2 The friction coefficient curve of the zirconium-based amorphous coating in the embodiment is shown in the tribological test. Detailed Implementation

[0023] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0024] Example 1

[0025] A method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction vessel specifically includes the following steps:

[0026] (1) Select 316 stainless steel as the substrate of the high temperature and high pressure reactor with dimensions of 100mm×100mm×50mm. First, pre-treat the 316 stainless steel by mechanically grinding the surface to make it smooth with a roughness Ra<0.5, or directly use corundum sandblasting to remove surface contaminants. The surface roughness after treatment is Ra 8.0-10.0. Then clean and dry with alcohol.

[0027] (2) 316 stainless steel was treated using electrical pulse technology, with a pulse width of 5 μs, a pulse interval of 100 μs, and a pulse current density of 200 A / mm. 2 During plasma spraying, continuous electrical pulse treatment is performed. When the pulse treatment temperature is above 200℃, the electrical pulse is stopped; when the substrate temperature is below 150℃, the electrical pulse is started.

[0028] (3) Select zirconium-based amorphous alloy powder containing 41.2% Zr, 13.8% Ti, 12.5% ​​Cu, 10% Ni, 22.5% Be and unavoidable impurities; the diameter of the zirconium-based amorphous coating powder is 10-55 μm; the wear-resistant and corrosion-resistant zirconium-based amorphous coating is prepared by plasma spraying technology. The spraying process is as follows: current 650A, voltage 40V, argon flow rate 80L / min, hydrogen flow rate 2L / min, spraying distance 90mm, linear velocity 600mm / s, argon as inert atmosphere protective gas, argon flow rate 7L / min, coating thickness 300μm.

[0029] Example 2

[0030] This embodiment describes a method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction vessel, comprising the following steps:

[0031] (1) Select Ti2 as the substrate of the high temperature and high pressure reactor with a size of 100mm×100mm×50mm. First, pre-treat Ti2 by mechanically grinding the surface to make it smooth with a roughness Ra<0.5, or directly use corundum sandblasting to remove surface contaminants. The surface roughness after treatment is Ra 8.0-10.0. Then clean and dry with alcohol.

[0032] (2) Ti2 was treated using electrical pulse technology with a pulse width of 20 μs, a pulse interval of 60 μs, and a pulse current density of 600 A / mm. 2 During plasma spraying, continuous electrical pulse treatment is performed. When the pulse treatment temperature is above 200℃, the electrical pulse is stopped; when the substrate temperature is below 150℃, the electrical pulse is started.

[0033] (3) Select zirconium-based amorphous alloy powder containing 40% Zr, 14% Ti, 15% Cu, 9% Ni, 22% Be and unavoidable impurities; the diameter of the zirconium-based amorphous coating powder is 10-55 μm; the wear-resistant and corrosion-resistant zirconium-based amorphous coating is prepared by plasma spraying technology. The spraying process is 550A current, 50V voltage, argon flow rate 90L / min, hydrogen flow rate 1L / min, spraying distance 80mm, linear velocity 500mm / s, argon as inert atmosphere protective gas, argon flow rate 6L / min, and coating thickness 250μm.

[0034] Example 3

[0035] This embodiment describes a method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction vessel, comprising the following steps:

[0036] (1) Select Zr as the substrate of the high temperature and high pressure reactor with a size of 100mm×100mm×50mm. First, Zr is pretreated by mechanically grinding the surface to make it smooth with a roughness Ra<0.5, or by directly using corundum sandblasting to remove surface contaminants. The surface roughness after treatment is Ra 8.0-10.0. Then, it is cleaned and dried with alcohol.

[0037] (2) Zr was treated using electrical pulse technology with a pulse width of 10 μs, a pulse interval of 50 μs, and a pulse current density of 1000 A / mm. 2 During plasma spraying, continuous electrical pulse treatment is performed. When the pulse treatment temperature is above 200℃, the electrical pulse is stopped; when the substrate temperature is below 150℃, the electrical pulse is started.

[0038] (3) Select zirconium-based amorphous alloy powder containing 45% Zr, 10% Ti, 10% Cu, 10% Ni, 25% Be and unavoidable impurities; the diameter of the zirconium-based amorphous coating powder is 10-55 μm; the wear-resistant and corrosion-resistant zirconium-based amorphous coating is prepared by plasma spraying technology. The spraying process is 500A current, 50V voltage, argon flow rate 85L / min, hydrogen flow rate 2L / min, spraying distance 100mm, linear velocity 700mm / s, argon as inert atmosphere protective gas, argon flow rate 7L / min, and coating thickness 350μm.

[0039] Comparative Example 1

[0040] This embodiment describes a method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction vessel, comprising the following steps:

[0041] (1) Select 316 stainless steel as the substrate of the high temperature and high pressure reactor with dimensions of 100mm×100mm×50mm. First, pre-treat the 316 stainless steel by mechanically grinding the surface to make it smooth with a roughness Ra<0.5, or directly use corundum sandblasting to remove surface contaminants. The surface roughness after treatment is Ra 8.0-10.0. Then clean and dry with alcohol.

[0042] (2) Select zirconium-based amorphous alloy powder containing 41.2% Zr, 13.8% Ti, 12.5% ​​Cu, 10% Ni, 22.5% Be and unavoidable impurities; the diameter of the zirconium-based amorphous coating powder is 10-55 μm; the wear-resistant and corrosion-resistant zirconium-based amorphous coating is prepared by plasma spraying technology. The spraying process is as follows: current 650A, voltage 40V, argon flow rate 80L / min, hydrogen flow rate 2L / min, spraying distance 90mm, linear velocity 600mm / s, argon as inert atmosphere protective gas, argon flow rate 7L / min, coating thickness 300μm.

[0043] Comparative Example 2

[0044] This embodiment describes a method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction vessel, comprising the following steps:

[0045] (1) Select Ti2 as the substrate of the high temperature and high pressure reactor with a size of 100mm×100mm×50mm. First, pre-treat Ti2 by mechanically grinding the surface to make it smooth with a roughness Ra<0.5, or directly use corundum sandblasting to remove surface contaminants. The surface roughness after treatment is Ra 8.0-10.0. Then clean and dry with alcohol.

[0046] (2) Select zirconium-based amorphous alloy powder containing 40% Zr, 14% Ti, 15% Cu, 9% Ni, 22% Be and unavoidable impurities; the diameter of the zirconium-based amorphous coating powder is 10-55 μm; the wear-resistant and corrosion-resistant zirconium-based amorphous coating is prepared by plasma spraying technology. The spraying process is as follows: current 550A, voltage 50V, argon flow rate 90L / min, hydrogen flow rate 1L / min, spraying distance 80mm, linear velocity 500mm / s, argon as inert atmosphere protective gas, argon flow rate 6L / min, coating thickness 250μm.

[0047] Comparative Example 3

[0048] This embodiment describes a method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction vessel, comprising the following steps:

[0049] (1) Select Zr as the substrate of the high temperature and high pressure reactor with a size of 100mm×100mm×50mm. First, Zr is pretreated by mechanically grinding the surface to make it smooth with a roughness Ra<0.5, or by directly using corundum sandblasting to remove surface contaminants. The surface roughness after treatment is Ra 8.0-10.0. Then, it is cleaned and dried with alcohol.

[0050] (2) Select zirconium-based amorphous alloy powder containing 45% Zr, 10% Ti, 10% Cu, 10% Ni, 25% Be and unavoidable impurities; the diameter of the zirconium-based amorphous coating powder is 10-55 μm; the wear-resistant and corrosion-resistant zirconium-based amorphous coating is prepared by plasma spraying technology. The spraying process is 500A current, 50V voltage, argon flow rate 85L / min, hydrogen flow rate 2L / min, spraying distance 100mm, linear velocity 700mm / s, argon as inert atmosphere protective gas, argon flow rate 7L / min, and coating thickness 350μm.

[0051] A wear-resistant and corrosion-resistant amorphous coating was prepared according to the examples, and its performance testing is described below:

[0052] (1) The porosity of the coating prepared in the example was analyzed using Image Pro Plus 6.0 image analysis software to evaluate the coating density by analyzing the porosity of the coating using the image method; the average value of five SEM images of the cross-section of the coating prepared in the example was calculated. Figure 2 SEM images of the cross-section of the coating were prepared for Example 1. It can be seen that the zirconium-based amorphous coating has good bonding with the 316 stainless steel substrate. The coating thickness is about 300 μm and the coating porosity is only 1%. The zirconium-based amorphous alloy coating has no large pores and has high density.

[0053] (2) The coating prepared in the example was subjected to microhardness test. A digital Vickers microhardness tester was used. The test force was 0.98N and the load time was 10s. Ten areas were randomly selected for measurement. The average hardness value was taken and is shown in Table 1.

[0054] (3) The bonding strength of the coating prepared in the example was tested. The bonding strength of the zirconium-based amorphous coating on the substrate was determined by an electronic universal testing machine. Commercial FM1000 adhesive was used to bond the coating surface and the loading fixture. The test speed was set to 0.021 mm / s. The maximum applied load was recorded and the bonding strength was calculated. See Table 1.

[0055] (4) The coatings prepared in the examples were subjected to corrosion resistance electrochemical tests. The corrosion tests were conducted using an electrochemical workstation with 20% H2SO4 as the corrosion solution. The polarization curves of the substrate and the coating were tested to calculate the corrosion rate. Table 1 shows the corrosion rates of the coatings and substrates prepared in the examples.

[0056] (5) The coating prepared in the example was subjected to a wear resistance test. The coating was subjected to a friction and wear test using a reciprocating friction and wear tester. The friction pair was a steel ball with a diameter of 6 mm, the load was 50 N, the friction rate was 3 mm / s, the sliding length was 3 mm, and the sliding time was 60 min. Figure 2 Table 1 shows the friction coefficient curve of the coating prepared in Example 1, and the wear rate of the coating and substrate prepared in the example.

[0057] Table 1. Mechanical and corrosion / wear properties of zirconium-based amorphous coatings prepared in Examples 1-3 and Comparative Examples 1-3

[0058]

[0059] According to the performance data of zirconium-based amorphous coatings in Table 1, the bonding strength and hardness of the sprayed examples 1-3 are higher than those of the comparative examples 1-3. The porosity, coating hardness, coating corrosion rate and coating wear rate of the examples are significantly improved compared with the comparative examples. The coating bonding strength is greater than 35 MPa. It can be seen from the comparison that the comprehensive mechanical properties of examples 1-3 of the present invention are excellent. Examples 1-3 involved electro-pulse treatment of the substrate material during plasma spraying, while Comparative Examples 1-3 did not involve electro-pulse treatment of the substrate material during plasma spraying, resulting in significant differences in the performance of the zirconium-based amorphous coating. Comparative Example 1 used the same substrate as Example 1, but exhibited significantly different corrosion and wear properties. This was primarily because Comparative Example 1 did not undergo electro-pulse treatment, leading to lower mechanical properties compared to Example 1. The lack of electro-pulse treatment in Comparative Example 1 resulted in a lower amorphous content, and the zirconium-based amorphous coating had lower hardness and strength than Example 1. The use of different substrate materials in Examples 1 compared to Examples 2-3 had a certain impact on the bonding strength and corrosion / wear performance of the zirconium-based amorphous coating. Since the hardness of Zr and Ti is greater than 316L, the bonding strength and wear rate of the zirconium-based amorphous coating on Zr and Ti substrates are greater than those on a Zr and Ti substrate. The sprayed coating, containing Zr and Ti elements, showed better lattice matching with the Zr and Ti substrate materials, resulting in higher bonding strength.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a wear and corrosion resistant zirconium-based amorphous coating on the surface of a reactor, characterized by: Continuous electrical pulse treatment is performed during plasma spraying, including the following steps: (1) First, the substrate is pretreated, including surface grinding, sandblasting and ultrasonic cleaning, and then cleaned and dried with alcohol; (2) The substrate is treated with AC pulse technology. When the pulse treatment temperature is above 200℃, the pulse is stopped; when the substrate temperature is below 150℃, the pulse is started. (3) A wear-resistant and corrosion-resistant zirconium-based amorphous coating was prepared by plasma spraying technology. The zirconium-based amorphous alloy composition and its mass percentage were: 40 ~ 45% Zr, 10 ~ 14% Ti, 10 ~ 15% Cu, 8 ~ 10% Ni, 20 ~ 25% Be and unavoidable impurities; The alternating current pulse treatment condition in the step (2) is: pulse width is 1 ~ 30 μs, pulse interval is 50 ~ 100 μs, and pulse current density is 200 ~ 1000 A / mm 2 .

2. The method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction vessel according to claim 1, characterized in that: The substrate is a high-temperature and high-pressure reactor material, including 316 stainless steel, titanium alloy, and zirconium alloy.

3. The method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction vessel according to claim 1 or 2, characterized in that: In step (1), the pretreatment of the substrate refers to grinding the substrate surface with mechanical grinding to achieve a roughness Ra < 0.5, or directly removing surface contaminants with corundum sandblasting to achieve a surface roughness Ra 8.0-10.0, and then cleaning and drying with alcohol.

4. The method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction vessel according to claim 3, characterized in that: In step (3), during plasma spraying, the current is 550~650 A, the voltage is 40~50 V, the argon flow rate is 80~90 L / min, the hydrogen flow rate is 1~2 L / min, the spraying distance is 80~100 mm, the linear velocity is 500~700 mm / s, and argon is used as an inert atmosphere protective gas with an argon flow rate of 6-8 L / min.

5. The method for preparing a wear-resistant and corrosion-resistant zirconium-based amorphous coating on the surface of a reaction vessel according to claim 1, characterized in that: In step (3), the diameter of the zirconium-based amorphous alloy powder is 10~55 μm; the thickness of the zirconium-based amorphous coating is 250~350 μm.

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