High-strength steel surface composite hydrogen barrier coating and preparation method

Abstract

This invention provides a composite hydrogen-barrier coating for high-strength steel and its preparation method. Belonging to the field of surface modification of metallic materials, the high-strength steel has a hardness of HV300-HV600, a tensile strength of 900-1200 MPa, a maximum thermal expansion coefficient of (8-20)×10⁻⁶ / K, and an elastic modulus between 100-200 GPa. The composite hydrogen-barrier coating consists of a transition layer and a hydrogen-barrier layer. The transition layer is composed of Al, Cr, and Zr, with each element having a molar ratio of not less than 30%. The hydrogen-barrier layer is composed of Al, Cr, Zr oxides and some unoxidized metal. Both the transition layer and the hydrogen-barrier layer have an amorphous structure. This coating utilizes the difference in binding energy between Al, Cr, and Zr and hydrogen to construct a material system with a tortuous hydrogen diffusion path and a high hydrogen diffusion barrier. Using magnetron sputtering technology, an amorphous (AlCrZr)O coating can be prepared on the surface of high-strength steel, effectively blocking and capturing hydrogen atoms, significantly improving the material's resistance to hydrogen embrittlement.

Description

Technical Field

[0001] This invention belongs to the field of surface modification of metallic materials, and specifically relates to a composite hydrogen barrier coating for high-strength steel and its preparation method. Background Technology

[0002] With the transformation of the global energy structure, hydrogen energy, as a clean and efficient energy form, is receiving increasing attention for its development and application. In the storage, transportation, and application of hydrogen energy, metallic materials, as key structural materials, are crucial for their safety and reliability. However, hydrogen embrittlement of metallic materials in a hydrogen environment—the penetration of hydrogen atoms into the metal lattice leading to material embrittlement—has become a major obstacle restricting their widespread application in the hydrogen energy field.

[0003] Hydrogen embrittlement reduces the plasticity and fracture toughness of metallic materials, and in severe cases, can even lead to catastrophic failure. This is particularly pronounced in high-strength steels, due to their widespread use in hydrogen-related environments, such as hydrogen storage tanks in hydrogen fuel cell vehicles and pressure vessels in hydrogen refueling stations. Traditional solutions, such as material alloying and microstructure optimization, while improving resistance to hydrogen embrittlement to some extent, often fall short of meeting increasingly stringent application requirements.

[0004] In recent years, surface coating technology has attracted much attention from researchers as an effective means of material modification. By applying a hydrogen-barrier coating to the surface of metallic materials, the hydrogen permeability can be effectively reduced, thereby mitigating or preventing hydrogen embrittlement. The hydrogen-barrier coating forms a physical barrier, prolonging the diffusion path of hydrogen atoms in the material, increasing the diffusion barrier, and thus reducing the concentration of hydrogen atoms inside the material, thereby reducing the risk of hydrogen embrittlement.

[0005] Although various hydrogen-barrier coatings have been researched and applied, such as metal coatings, oxide coatings, and carbide coatings, they still have some problems in practical applications, such as insufficient adhesion to the substrate material, poor thermal stability, and high preparation costs. Furthermore, the hydrogen-barrier mechanism of existing coatings is not fully understood, and there is still considerable room for optimization and improvement of coating performance. Summary of the Invention

[0006] To address the shortcomings of the existing technologies, this invention provides a composite hydrogen-barrier coating for high-strength steel surfaces and its preparation method. This coating utilizes the differences in the binding energies of Al, Cr, and Zr with hydrogen to construct a material system with a tortuous hydrogen diffusion path and a high hydrogen diffusion barrier. Using magnetron sputtering technology, an amorphous (AlCrZr)O coating can be prepared on the surface of high-strength steel, effectively blocking and capturing hydrogen atoms, significantly improving the material's resistance to hydrogen embrittlement.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a composite hydrogen-resistant coating on the surface of high-strength steel, wherein the high-strength steel has a hardness of HV300-HV600, a tensile strength of 900-1200MPa, and a maximum thermal expansion coefficient of (8-20)×10⁻⁶. -6 / K, with an elastic modulus between 100-200 GPa; the composite hydrogen barrier coating consists of a transition layer and a hydrogen barrier layer. The transition layer is composed of three elements: Al, Cr, and Zr, with a molar ratio of each element not less than 30%. The hydrogen barrier layer is composed of Al, Cr, Zr oxides and some unoxidized metals. The transition layer and the hydrogen barrier layer are amorphous structures.

[0008] Furthermore, the thickness of the transition layer is 20-30 μm; the thickness of the hydrogen barrier layer is 80-170 μm.

[0009] On the other hand, the present invention provides a method for preparing the above-mentioned composite hydrogen barrier coating, comprising: selecting high-strength steel and a target material, and pre-treating the surface of the high-strength steel to be coated; and coating the surface to be coated by magnetron sputtering.

[0010] Furthermore, the target material includes AlCr target and Zr target.

[0011] Furthermore, the pretreatment includes: using 400# to 5000# SiC sandpaper to grind the high-strength steel surface to be coated step by step until the surface is free of voids and large scratches, then using diamond polishing paste for mirror polishing, the surface roughness of the prepared product is less than 0.16μm, and finally using an ultrasonic cleaner to immerse the sample in deionized water, anhydrous ethanol and acetone for 10-30 minutes in sequence and then dry it.

[0012] Furthermore, the magnetron sputtering process includes vacuuming, bias cleaning, and coating; the vacuum level after vacuuming is no greater than 2.0 × 10⁻⁶. -3 Pa.

[0013] Furthermore, the bias cleaning process is as follows: the substrate is heated at a preparation temperature of 180-220℃, and the vacuum degree in the chamber is no greater than 1.8 × 10⁻⁶. -3 When the pressure reaches Pa, open the shut-off valve, set the flow limiting valve parameter to 100°, the argon flow rate to 30 sccm, and the voltage to -900V, so that the pressure in the chamber is maintained above 1.0Pa for bias cleaning, and the cleaning time is not less than 10 minutes.

[0014] Furthermore, the coating process of the transition layer is as follows: the argon flow rate is set to 25-30 sccm, the AlCr target power is 140-160W, the Zr target power is 90-110W, the working gas pressure in the chamber is 0.4-0.6Pa, the substrate rotation speed is 9-11 r / min, the deposition temperature is 180-220℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, and the deposition time is 4-6 min.

[0015] Furthermore, the deposition process of the hydrogen barrier layer is as follows: the argon flow rate is set to 25-30 sccm, the AlCr target power is 140-160W, the Zr target power is 90-110W, the working pressure in the chamber is 0.4-0.6Pa, the substrate rotation speed is 9-11 r / min, the deposition temperature is 180-220℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, the oxygen flow rate is adjusted to 7-8 sccm, and the deposition time is 7-8 min; the oxygen flow rate is adjusted to 5-6 sccm, and the deposition time is 5-6 min; the oxygen flow rate is adjusted to 2-3 sccm, and the deposition time is 16-18 min.

[0016] Furthermore, the deposition process of the hydrogen barrier layer is as follows: the argon flow rate is set to 30 sccm, the AlCr target power is 150W, the Zr target power is 100W, the working gas pressure in the chamber is 0.5Pa, the substrate rotation speed is 10r / min, the deposition temperature is 200℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, the oxygen flow rate is adjusted to 8 sccm, and the deposition time is 7min; the oxygen flow rate is adjusted to 5 sccm, and the deposition time is 5min; the oxygen flow rate is adjusted to 3 sccm, and the deposition time is 18min.

[0017] Compared with the prior art, the technical solution provided by the present invention brings the following beneficial effects:

[0018] (1) This invention utilizes the significant differences in the binding energies of Al, Cr, and Zr with hydrogen. This difference forms the basis for constructing a tortuous hydrogen diffusion path and a high hydrogen diffusion barrier, which is crucial for slowing down the diffusion rate of hydrogen in materials. Using magnetron sputtering, an AlCrZr coating with an amorphous structure can be prepared. The lack of grain boundaries in the amorphous structure reduces the rapid hydrogen diffusion channels, further improving the hydrogen barrier efficiency of the coating. Compared with single metal oxide coatings, AlCrZr-based oxide coatings, through the synergistic effect of multiple elements, not only improve the cohesive force of the coating but also enhance its ability to adsorb and capture hydrogen, thus performing better in suppressing hydrogen permeation. High-entropy alloy oxide coatings, due to their multi-element composition, suffer from complex inter-element interactions, uncontrollable lattice distortion, and unpredictable hydrogen diffusion behavior. In contrast, AlCrZr-based medium-entropy alloy oxide coatings, through carefully designed elemental composition, optimize inter-element interactions, reduce unfavorable lattice distortion, and thus provide a more stable hydrogen diffusion path.

[0019] (2) The coating provided in this application utilizes the difference in binding energy between Al, Cr, and Zr and hydrogen to construct a material system with a tortuous hydrogen diffusion path and a high hydrogen diffusion barrier. By using magnetron sputtering technology, an amorphous (AlCrZr)O coating can be prepared on the surface of high-strength steel to effectively block and capture hydrogen atoms, thereby significantly improving the material's resistance to hydrogen embrittlement.

[0020] (3) Regarding the high-strength steel in the prior art, the high-strength steel has the following physical properties: hardness of HV300-HV600, tensile strength of 900-1200MPa, and a maximum coefficient of thermal expansion of (8-20)×10. -6 / K, due to the high mechanical performance indicators mentioned above, it is difficult to directly apply the coating using the technical solutions disclosed in the prior art. In order to meet the subsequent processing requirements, the coating needs to be able to be processed to a certain extent after coating. The composite hydrogen barrier coating prepared using the technical solution of this application can meet the requirement that the minimum bending radius is 2cm when the thickness of high-strength steel is within 5mm, and no cracks will be generated between the coating and the surface of high-strength steel, which greatly expands the application scope and processability of subsequent products. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1Here are SEM images of the surface morphology of the composite hydrogen barrier coating provided in Embodiment 1 of the present invention, where a is the coating surface and b is a cross-section.

[0023] Figure 2 XPS fine spectrum of the composite hydrogen barrier coating provided in the embodiments of the present invention;

[0024] Figure 3 Hydrogen permeation curve of the composite hydrogen barrier coating provided in the embodiments of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The specific embodiments of this invention are not limited to those given herein, and those skilled in the art can make similar improvements without departing from the spirit of this invention. Therefore, this invention is not limited to the disclosed specific embodiments.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used is for describing particular embodiments only and does not limit the scope of the invention.

[0027] This invention provides a composite hydrogen-barrier coating for a high-strength steel surface. The high-strength steel has a hardness of HV300-HV600, a tensile strength of 900-1200 MPa, a maximum thermal expansion coefficient of (8-20)×10-6 / K, and an elastic modulus between 100-200 GPa. The composite hydrogen-barrier coating consists of a transition layer and a hydrogen-barrier layer. The transition layer is composed of Al, Cr, and Zr, with a molar ratio of each element not less than 30%. The hydrogen-barrier layer is composed of Al, Cr, Zr oxides and some unoxidized metal. Both the transition layer and the hydrogen-barrier layer have an amorphous structure.

[0028] First, this invention utilizes the fact that the binding energies of Al, Cr, and Zr with hydrogen differ significantly. This difference forms the basis for constructing a tortuous hydrogen diffusion path and a high hydrogen diffusion barrier, which is crucial for slowing down the diffusion rate of hydrogen in materials. Amorphous AlCrZr coatings can be prepared using magnetron sputtering technology. The lack of grain boundaries in the amorphous structure reduces the rapid diffusion channels of hydrogen, further improving the hydrogen barrier efficiency of the coating. Compared with single metal oxide coatings, AlCrZr-based oxide coatings, through the synergistic effect of multiple elements, not only improve the cohesiveness of the coating but also enhance its ability to adsorb and capture hydrogen, thus performing better in suppressing hydrogen permeation. High-entropy alloy oxide coatings, due to their multi-element composition, suffer from complex inter-element interactions, uncontrollable lattice distortion, and unpredictable hydrogen diffusion behavior. In contrast, AlCrZr-based medium-entropy alloy oxide coatings, through carefully designed elemental composition, optimize inter-element interactions, reduce unfavorable lattice distortion, and thus provide a more stable hydrogen diffusion path. Furthermore, the coating provided in this application utilizes the differences in binding energies between Al, Cr, and Zr with hydrogen to construct a material system with a tortuous hydrogen diffusion path and a high hydrogen diffusion barrier. Magnetron sputtering technology can be used to prepare an amorphous (AlCrZr)O coating on the surface of high-strength steel, effectively blocking and trapping hydrogen atoms, thus significantly improving the material's resistance to hydrogen embrittlement. Furthermore, regarding the high-strength steel in the prior art, the high-strength steel has the following physical properties: hardness of HV300-HV600, tensile strength of 900-1200 MPa, and a maximum coefficient of thermal expansion of (8-20)×10⁻⁶. -6 / K, due to the high mechanical performance indicators mentioned above, it is difficult to directly apply the coating using the technical solutions disclosed in the prior art. In order to meet the subsequent processing requirements, the coating needs to be able to be processed to a certain extent after coating. The composite hydrogen barrier coating prepared using the technical solution of this application can meet the requirement that the minimum bending radius is 2cm when the thickness of high-strength steel is within 5mm, and no cracks will be generated between the coating and the surface of high-strength steel, which greatly expands the application scope and processability of subsequent products.

[0029] It should be noted that the high-strength steel in this invention is 12Cr2Mo1R steel or 17-4PH.

[0030] Specifically, the thickness of the transition layer is 20-30 μm; the thickness of the hydrogen barrier layer is 80-170 μm. The hydrogen barrier layer should not be too thin. While a thinner layer increases manufacturing efficiency, it weakens the hydrogen barrier performance. Furthermore, a thinner layer lacks sufficient transition distance between the hydrogen barrier layer and the transition layer, making it prone to cracking between the hydrogen barrier layer and the high-strength steel substrate or the transition layer during subsequent bending processes. However, the hydrogen barrier coating should not be too thick. Excessive thickness increases preparation time, and because the hydrogen barrier layer is a metal oxide layer, its brittleness increases the probability of cracking on the outer surface of the coating. The transition layer is used to coordinate the deformation of the hydrogen barrier layer and the high-strength steel substrate at different temperatures, preventing inconsistent deformation that could lead to interface cracks. Compared to (AlCrZr)O, AlCrZr bonds more tightly to the high-strength steel substrate. Therefore, setting the transition layer thickness to 20-30 μm not only satisfies the above conditions but also reduces the thickness of the transition layer, avoiding the negative impact of an excessively thick composite hydrogen barrier coating on the bending performance of the prepared product.

[0031] The present invention also provides a method for preparing the above-mentioned composite hydrogen barrier coating, comprising:

[0032] S1 selects high-strength steel and a target material, and pre-treats the surface of the high-strength steel to be coated.

[0033] Specifically, for illustrative purposes, in this invention, the high-strength steel selected is 12Cr2Mo1R and 17-4PH. The components and their mass percentages of the 12Cr2Mo1R steel are as follows: C: 0.14%, Si: 0.12%, Mn: 0.57%, P: 0.01%, Cr: 2.64%, Ni: 0.02%, Co: 3.67%, Nb: 0.01%, Al: 0.07%.

[0034] The components and their mass percentages of the 17-4PH are as follows: C: 0.03%, Si: 0.56%, Mn: 0.51%, P: 0.02%, Cr: 16.75%, Ni: 3.99%, Cu: 3.67%, Nb: 0.28%.

[0035] The target material used is a 99.99% pure AlCr composite metal target (φ76.2×5mm) manufactured by Zhongnuo New Materials Technology Co., Ltd. 3 ) and a Zr target with a purity of 99.99% (φ76.2×5mm) 3 ).

[0036] The pretreatment includes: using 400# to 5000# SiC sandpaper to grind the 12Cr2Mo1R steel surface to be coated step by step until there are no voids or large scratches on the surface, then using diamond polishing paste for mirror polishing, the surface roughness of the prepared product is less than 0.16μm, and finally using an ultrasonic cleaner to soak and clean the sample in deionized water, anhydrous ethanol and acetone for 10-30 minutes in sequence and then drying.

[0037] S2 uses magnetron sputtering to coat the surface to be coated.

[0038] The magnetron sputtering process includes vacuuming, bias cleaning, deposition of a transition layer, and deposition of a hydrogen barrier layer; the vacuum level after vacuuming is no greater than 2.0 × 10⁻⁶. -3 Pa.

[0039] The bias cleaning process is as follows: the substrate is heated at a preparation temperature of 180-220℃, and the vacuum degree in the chamber is no greater than 1.8×10⁻⁶. -3 When the pressure reaches Pa, open the shut-off valve, set the flow limiting valve parameter to 100°, the argon flow rate to 30 sccm, and the voltage to -900V to maintain the chamber pressure above 1.0 Pa for bias cleaning. The cleaning time should be no less than 10 minutes. This ensures that contaminants on the substrate surface are removed, the substrate surface is activated, and the adhesion of the coating is guaranteed.

[0040] The coating process of the transition layer is as follows: the argon flow rate is set to 25-30 sccm, the AlCr target power is 140-160W, the Zr target power is 90-110W, the working gas pressure in the chamber is 0.4-0.6Pa, the substrate rotation speed is 9-11 r / min, the deposition temperature is 180-220℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, and the deposition time is 4-6min.

[0041] The deposition process of the hydrogen barrier layer is as follows: the argon flow rate is set to 25-30 sccm, the AlCr target power is 140-160W, the Zr target power is 90-110W, the working pressure in the chamber is 0.4-0.6Pa, the substrate rotation speed is 9-11 r / min, the deposition temperature is 180-220℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, the oxygen flow rate is adjusted to 7-8 sccm, and the deposition time is 7-8 min; the oxygen flow rate is adjusted to 5-6 sccm, and the deposition time is 5-6 min; the oxygen flow rate is adjusted to 2-3 sccm, and the deposition time is 16-18 min.

[0042] Preferably, the deposition process of the hydrogen barrier layer is as follows: the argon flow rate is set to 30 sccm, the AlCr target power is 150W, the Zr target power is 100W, the working gas pressure in the chamber is 0.5Pa, the substrate rotation speed is 10r / min, the deposition temperature is 200℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, the oxygen flow rate is adjusted to 8 sccm, and the deposition time is 7min; the oxygen flow rate is adjusted to 5 sccm, and the deposition time is 5min; the oxygen flow rate is adjusted to 3 sccm, and the deposition time is 18min.

[0043] The above preparation method produces a composite hydrogen barrier coating surface (AlCrZr)O with a metal atom oxidation degree of Al and Zr being completely oxidized, Cr being oxidized by more than 70%, and an oxygen ion content of at least 75%.

[0044] In this embodiment of the invention, the performance of the prepared composite hydrogen barrier coating is tested, including:

[0045] Osmotic current density: The test was conducted in accordance with the national standard "Determination of hydrogen permeability of metallic materials - Part 1: Steady-state current method" (GB / T 35439.1-2017).

[0046] To further illustrate the present invention, the following detailed description of a wide-temperature-range multiphase low-expansion lightweight aluminum-based composite material provided by the present invention is provided in conjunction with embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0047] Example 1

[0048] This invention provides a method for preparing a composite hydrogen-barrier coating on a high-strength steel surface, comprising:

[0049] S1 selects high-strength steel and a target material, and pre-treats the surface of the high-strength steel to be coated.

[0050] Using 12Cr2Mo1R steel and a target material, the surface of the 12Cr2Mo1R steel to be coated is polished and cleaned.

[0051] S2 uses magnetron sputtering to coat the surface to be coated.

[0052] Turn on the magnetron sputtering equipment, place the substrate material on the sample stage of the substrate stage, close the chamber door, and evacuate to a vacuum level of 2.0 × 10⁻⁶. -3 Below Pa.

[0053] The bias cleaning process is as follows: 12Cr2Mo1R steel is heated and cleaned under bias. The preparation temperature is set to 200℃ to start heating the 12Cr2Mo1R steel. When the predetermined temperature is reached and the vacuum degree in the chamber is 1.8×10⁻⁶, the cleaning process continues. -3When the pressure reaches Pa, open the shut-off valve, set the flow limiting valve parameter to 100° (adjustment range is 0~1000°), set the argon flow rate to 30sccm, and set the voltage to -900V to maintain the pressure in the chamber above 1.0Pa for bias cleaning. First, bombard the 12Cr2Mo1R steel surface with Ar+ particles for 10 minutes to ensure that contaminants on the 12Cr2Mo1R steel surface are removed, the 12Cr2Mo1R steel surface is activated, and the adhesion of the coating is guaranteed.

[0054] The coating process of the transition layer is as follows: the argon flow rate is set to 30 sccm, the AlCr target power is 150W, the Zr target power is 100W, the working gas pressure in the chamber is 0.5Pa, the substrate rotation speed is 10r / min, the deposition temperature is 200℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, the deposition time is 5min, and the thickness of the prepared transition layer is 24μm.

[0055] The deposition process of the hydrogen barrier layer is as follows: Argon flow rate is set to 30 sccm, AlCr target power is 150 W, Zr target power is 100 W, chamber working pressure is 0.5 Pa, substrate rotation speed is 10 r / min, deposition temperature is 200℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100 V, oxygen flow rate is adjusted to 8 sccm, deposition time is 7 min, oxygen flow rate is adjusted to 5 sccm, deposition time is 5 min, and oxygen flow rate is adjusted to 3 sccm, deposition time is 18 min. The morphology of the prepared composite hydrogen barrier coating is shown in the figure below. Figure 1 As shown in 1a and 1b, the thickness of the prepared hydrogen barrier layer is 124 μm. In summary, the total thickness of the composite hydrogen barrier coating is 148 μm.

[0056] The prepared coating has an amorphous structure, such as Figure 2 This invention uses XPS detection for different oxygen flow rates. It shows that on the surface of the composite hydrogen barrier coating (AlCrZr)O, some Cr is not completely oxidized, and the oxygen ion content is 77.5%. Figure 3 As shown, under different oxygen flow rates at the end of the preparation process, the lowest osmotic current density is observed when the oxygen flow rate is 3 sccm, which is 0.21 μA·cm. -2 Through testing, it was found that when the thickness of the high-strength steel is 5mm, the minimum bending radius is 2cm, and there are no cracks at the interface between the composite hydrogen barrier coating and the 12Cr2Mo1R steel substrate.

[0057] Example 2

[0058] This invention provides a method for preparing a composite hydrogen-barrier coating on a high-strength steel surface, comprising:

[0059] S1 selects high-strength steel and a target material, and pre-treats the surface of the high-strength steel to be coated.

[0060] Using 12Cr2Mo1R steel and a target material, the surface of the 12Cr2Mo1R steel to be coated is polished and cleaned.

[0061] S2 uses magnetron sputtering to coat the surface to be coated.

[0062] Turn on the magnetron sputtering equipment, place the substrate material on the sample stage of the substrate stage, close the chamber door, and evacuate to a vacuum level of 2.0 × 10⁻⁶. -3 Below Pa.

[0063] The bias cleaning process is as follows: 12Cr2Mo1R steel is heated and cleaned under bias. The preparation temperature is set to 200℃ to start heating the 12Cr2Mo1R steel. When the predetermined temperature is reached and the vacuum degree in the chamber is 1.8×10⁻⁶, the cleaning process continues. -3 When the pressure reaches Pa, open the shut-off valve, set the flow limiting valve parameter to 100° (adjustment range is 0~1000°), set the argon flow rate to 30sccm, and set the voltage to -900V to maintain the pressure in the chamber above 1.0Pa for bias cleaning. First, bombard the 12Cr2Mo1R steel surface with Ar+ particles for 10 minutes to ensure that contaminants on the 12Cr2Mo1R steel surface are removed, the 12Cr2Mo1R steel surface is activated, and the adhesion of the coating is guaranteed.

[0064] The coating process of the transition layer is as follows: the argon flow rate is set to 25 sccm, the AlCr target power is 140W, the Zr target power is 90W, the working gas pressure in the chamber is 0.4Pa, the substrate rotation speed is 9r / min, the deposition temperature is 180℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, the deposition time is 4min, and the thickness of the prepared transition layer is 20μm.

[0065] The deposition process for the hydrogen barrier layer is as follows: Argon flow rate is set to 25 sccm, AlCr target power is 140 W, Zr target power is 90 W, chamber working pressure is 0.4 Pa, substrate rotation speed is 9 r / min, deposition temperature is 180℃, magnetron sputtering bias is adjusted to -100V, oxygen flow rate is adjusted to 7 sccm, deposition time is 7 min, oxygen flow rate is adjusted to 5 sccm, deposition time is 5 min, and oxygen flow rate is adjusted to 2 sccm, deposition time is 16 min. The thickness of the prepared hydrogen barrier layer is 80 μm. In summary, the total thickness of the composite hydrogen barrier coating is 100 μm.

[0066] The prepared coating has an amorphous structure and a composite hydrogen barrier coating surface of (AlCrZr)O. Some Cr is not completely oxidized, with an oxidation degree of 77% and an oxygen ion content of 80%. The measured permeation current density of the sample is 0.31 μA·cm. -2Through testing, it was found that when the thickness of the high-strength steel is 5mm, the minimum bending radius is 2cm, and there are no cracks at the interface between the composite hydrogen barrier coating and the 12Cr2Mo1R steel substrate.

[0067] Example 3

[0068] This invention provides a method for preparing a composite hydrogen-barrier coating on a high-strength steel surface, comprising:

[0069] S1 selects high-strength steel and a target material, and pre-treats the surface of the high-strength steel to be coated.

[0070] Using 12Cr2Mo1R steel and a target material, the surface of the 12Cr2Mo1R steel to be coated is polished and cleaned.

[0071] S2 uses magnetron sputtering to coat the surface to be coated.

[0072] Turn on the magnetron sputtering equipment, place the substrate material on the sample stage of the substrate stage, close the chamber door, and evacuate to a vacuum level of 2.0 × 10⁻⁶. -3 Below Pa.

[0073] The bias cleaning process is as follows: 12Cr2Mo1R steel is heated and cleaned under bias. The preparation temperature is set to 200℃ to start heating the 12Cr2Mo1R steel. When the predetermined temperature is reached and the vacuum degree in the chamber is 1.8×10⁻⁶, the cleaning process continues. -3 When the pressure reaches Pa, open the shut-off valve, set the flow limiting valve parameter to 100° (adjustment range is 0~1000°), set the argon flow rate to 30sccm, and set the voltage to -900V to maintain the pressure in the chamber above 1.0Pa for bias cleaning. First, bombard the 12Cr2Mo1R steel surface with Ar+ particles for 10 minutes to ensure that contaminants on the 12Cr2Mo1R steel surface are removed, the 12Cr2Mo1R steel surface is activated, and the adhesion of the coating is guaranteed.

[0074] The coating process of the transition layer is as follows: the argon flow rate is set to 30 sccm, the AlCr target power is 160W, the Zr target power is 110W, the working gas pressure in the chamber is 0.6Pa, the substrate rotation speed is 11r / min, the deposition temperature is 220℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, the deposition time is 6min, and the thickness of the prepared transition layer is 30μm.

[0075] The deposition process for the hydrogen barrier layer is as follows: Argon flow rate is set to 30 sccm, AlCr target power is 160 W, Zr target power is 110 W, chamber working pressure is 0.6 Pa, substrate rotation speed is 11 r / min, deposition temperature is 220℃, magnetron sputtering bias is adjusted to -100V, oxygen flow rate is adjusted to 8 sccm, deposition time is 8 min, oxygen flow rate is adjusted to 6 sccm, deposition time is 6 min, and oxygen flow rate is adjusted to 3 sccm, deposition time is 18 min. The thickness of the prepared hydrogen barrier layer is 170 μm. In summary, the total thickness of the composite hydrogen barrier coating is 200 μm.

[0076] The prepared coating has an amorphous structure and a composite hydrogen barrier coating surface of (AlCrZr)O. Some Cr is not completely oxidized, with an oxidation degree of 74% and an oxygen ion content of 75%. The measured permeation current density of the sample is 0.53 μA·cm. -2 Through testing, it was found that when the thickness of the high-strength steel is 5mm, the minimum bending radius is 2cm, and there are no cracks at the interface between the composite hydrogen barrier coating and the 12Cr2Mo1R steel substrate.

[0077] Example 4

[0078] This invention provides a method for preparing a composite hydrogen-barrier coating on a high-strength steel surface, comprising:

[0079] S1 selects high-strength steel and a target material, and pre-treats the surface of the high-strength steel to be coated.

[0080] Using 17-4PH steel and a target material, the surface of the 17-4PH steel to be coated is polished and cleaned.

[0081] S2 uses magnetron sputtering to coat the surface to be coated.

[0082] Turn on the magnetron sputtering equipment, place the substrate material on the sample stage of the substrate stage, close the chamber door and evacuate to a vacuum level below 2.0×10-3 Pa.

[0083] The bias cleaning process is as follows: 17-4PH steel is heated and biased cleaned. The preparation temperature is set to 200℃ to start heating the 17-4PH steel. When the predetermined temperature is reached and the vacuum degree in the chamber is 1.8×10-3Pa, the shut-off valve is opened, the flow limiting valve parameter is set to 100° (adjustment range is 0~1000°), the argon flow rate is set to 30sccm, and the voltage is set to -900V to keep the pressure in the chamber above 1.0Pa for bias cleaning. The surface of 17-4PH steel is first bombarded with Ar+ particles for 10 minutes to ensure that the contaminants on the surface of 17-4PH steel are removed, the surface of 17-4PH steel is activated, and the adhesion of the coating is guaranteed.

[0084] The coating process of the transition layer is as follows: the argon flow rate is set to 30 sccm, the AlCr target power is 150W, the Zr target power is 100W, the working gas pressure in the chamber is 0.5Pa, the substrate rotation speed is 10r / min, the deposition temperature is 200℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, the deposition time is 5min, and the thickness of the prepared transition layer is 23.8μm.

[0085] The deposition process for the hydrogen barrier layer is as follows: Argon flow rate is set to 30 sccm, AlCr target power is 150 W, Zr target power is 100 W, chamber working pressure is 0.5 Pa, substrate rotation speed is 10 r / min, deposition temperature is 200℃, magnetron sputtering bias is adjusted to -100 V, oxygen flow rate is adjusted to 8 sccm, deposition time is 7 min, oxygen flow rate is adjusted to 5 sccm, deposition time is 5 min, and oxygen flow rate is adjusted to 3 sccm, deposition time is 18 min. The thickness of the prepared hydrogen barrier layer is 122 μm. In summary, the total thickness of the composite hydrogen barrier coating is 145.8 μm.

[0086] The prepared coating has an amorphous structure and a composite hydrogen barrier coating surface of (AlCrZr)O. Some Cr is not completely oxidized, with an oxidation degree of 76.0% and an oxygen ion content of 77.5%. The measured permeation current density of the sample is 0.27 μA·cm. -2 Through testing, it was found that when the thickness of the high-strength steel is 5mm, the minimum bending radius is 2cm, and there are no cracks at the interface between the composite hydrogen barrier coating and the 17-4PH steel substrate.

[0087] Comparative Example 1

[0088] Unlike Example 1, in step S2 of this comparative example, the deposition time of the transition layer is 17 min, and the thickness of the prepared transition layer is 18 μm.

[0089] The prepared coating has an amorphous structure; through testing, cracks were found in the composite hydrogen barrier coating when the thickness of the high-strength steel was 5 mm and the bending radius was 15 cm.

[0090] Comparative Example 2

[0091] Unlike Example 1, in step S2 of this comparative example, the deposition time of the transition layer is 20 min, and the thickness of the prepared transition layer is 34 μm.

[0092] The prepared coating has an amorphous structure; through testing, cracks were found on the outer surface of the composite hydrogen barrier coating when the thickness of the high-strength steel was 5 mm and the bending radius was 15 cm.

[0093] Comparative Example 3

[0094] Unlike Example 1, in step S2 of this comparative example, the oxygen flow rate is 8 sccm and the deposition time is 30 min.

[0095] The prepared coating has an amorphous structure. Through testing, when the thickness of the high-strength steel is 5 mm and the bending radius is 20 cm, there are cracks between the hydrogen barrier layer and the transition layer. Al, Cr and Zr are not completely oxidized, and the oxygen ion content is 60%.

[0096] Comparative Example 4

[0097] Unlike Example 1, in step S2 of this comparative example, the oxygen flow rate is 3 sccm and the deposition time is 30 min.

[0098] The prepared coating has an amorphous structure; through testing, cracks were found between the hydrogen barrier layer and the transition layer when the thickness of the high-strength steel was 5 mm and the bending radius was 25 cm.

[0099] Comparative Example 5

[0100] Unlike Example 1, in step S2 of this comparative example, the oxygen flow rate was adjusted to 8 sccm and the deposition time was 7 min, while the oxygen flow rate was adjusted to 3 sccm and the deposition time was 23 min.

[0101] The prepared coating has an amorphous structure; through testing, cracks were found between the hydrogen barrier layer and the transition layer when the thickness of the high-strength steel was 5 mm and the bending radius was 10 cm.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A composite hydrogen-barrier coating for high-strength steel surfaces, characterized in that, The high-strength steel has a hardness of HV300-HV600, a tensile strength of 900-1200MPa, and a maximum thermal expansion coefficient of (8-20)×10⁻⁶. -6 / K, with an elastic modulus between 100-200GPa; The composite hydrogen barrier coating consists of a transition layer and a hydrogen barrier layer. The transition layer is composed of three elements: Al, Cr, and Zr, with each element having a molar ratio of not less than 30%. The hydrogen barrier layer is composed of Al, Cr, Zr oxides and some unoxidized metals. The transition layer and hydrogen barrier layer are amorphous structures; The thickness of the transition layer is 20-30 μm; the thickness of the hydrogen barrier layer is 80-170 μm. The deposition process of the hydrogen barrier layer is as follows: the argon flow rate is set to 25-30 sccm, the AlCr target power is 140-160W, the Zr target power is 90-110W, the working pressure in the chamber is 0.4-0.6Pa, the substrate rotation speed is 9-11 r / min, the deposition temperature is 180-220℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, the oxygen flow rate is adjusted to 7-8 sccm, and the deposition time is 7-8 min; the oxygen flow rate is adjusted to 5-6 sccm, and the deposition time is 5-6 min; the oxygen flow rate is adjusted to 2-3 sccm, and the deposition time is 16-18 min.

2. A method for preparing the composite hydrogen barrier coating as described in claim 1, characterized in that, include: Select high-strength steel and a target material, and pre-treat the surface of the high-strength steel to be coated; Magnetron sputtering is used to coat the surface to be coated.

3. The preparation method according to claim 2, characterized in that, The pretreatment includes: using 400# to 5000# SiC sandpaper to grind the high-strength steel surface to be coated step by step until there are no voids or large scratches on the surface, then using diamond polishing paste for mirror polishing, the surface roughness of the prepared product is less than 0.16μm, and finally using an ultrasonic cleaner to soak and clean the sample in deionized water, anhydrous ethanol and acetone for 10-30 minutes in sequence and then drying.

4. The preparation method according to claim 2, characterized in that, The magnetron sputtering process includes vacuuming, bias cleaning, deposition of a transition layer, and deposition of a hydrogen barrier layer. The vacuum level after evacuation is no greater than 2.0 × 10⁻⁶. -3 Pa.

5. The preparation method according to claim 4, characterized in that, The bias cleaning process is as follows: the substrate is heated at a preparation temperature of 180-220℃, and the vacuum degree in the chamber is no greater than 1.8×10⁻⁶. -3 When the pressure reaches Pa, open the shut-off valve, set the flow limiting valve parameter to 100°, the argon flow rate to 30 sccm, and the voltage to -900V, so that the pressure in the chamber is maintained above 1.0Pa for bias cleaning, and the cleaning time is not less than 10 minutes.

6. The preparation method according to claim 4, characterized in that, The coating process of the transition layer is as follows: the argon flow rate is set to 25-30 sccm, the AlCr target power is 140-160W, the Zr target power is 90-110W, the working gas pressure in the chamber is 0.4-0.6Pa, the substrate rotation speed is 9-11 r / min, the deposition temperature is 180-220℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, and the deposition time is 4-6min.

7. The preparation method according to claim 2, characterized in that, The deposition process of the hydrogen barrier layer is as follows: the argon flow rate is set to 30 sccm, the AlCr target power is 150W, the Zr target power is 100W, the working gas pressure in the chamber is 0.5Pa, the substrate rotation speed is 10r / min, the deposition temperature is 200℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, the oxygen flow rate is adjusted to 8 sccm, and the deposition time is 7min; the oxygen flow rate is adjusted to 5 sccm, and the deposition time is 5min; the oxygen flow rate is adjusted to 3 sccm, and the deposition time is 18min.

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