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

Abstract

The application provides a high-strength steel surface hydrogen barrier coating and a preparation method thereof. The high-strength steel has a hardness of HV300-HV600, a tensile strength of 900-1200 MPa, and a thermal expansion coefficient of (8-20) x 10 ‑6 -6 / K, and an elastic modulus of 100-200 GPa. The hydrogen barrier coating is composed of Al, Cr and Zr, and the molar ratio of each element is not less than 30%. The hydrogen barrier coating is an amorphous structure. The coating utilizes the difference in the binding energy of Al, Cr and Zr and hydrogen to construct a coating structure with a tortuous hydrogen diffusion path and a high hydrogen diffusion potential barrier. Through a magnetron sputtering technology, the chemical composition and microstructure of the coating can be accurately controlled, and the coating can be closely combined with the high-strength steel substrate and have excellent hydrogen barrier performance.

Description

Technical Field

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

[0002] With the transformation of the global energy structure and the demand for sustainable development, hydrogen energy, as a clean and efficient energy carrier, is finding increasingly wider applications. High-strength steel is widely used as a structural material, particularly in key facilities such as hydrogen fuel cell vehicles, hydrogen refueling stations, and future nuclear power plants, due to its excellent mechanical properties. However, applications in hydrogen environments present severe challenges to high-strength steel. Hydrogen atoms, as the smallest atoms in nature, can easily penetrate the crystal structure of metallic materials, even at extremely low concentrations, potentially causing severe hydrogen embrittlement. This hydrogen embrittlement leads to a significant decrease in the mechanical strength and elongation of the material, increasing the risk of structural failure and limiting the application and development of high-strength steel in the hydrogen energy field.

[0003] Traditional solutions typically focus on material selection and design to enhance inherent resistance to hydrogen embrittlement. However, these methods often fall short of meeting increasingly demanding performance requirements. To effectively prevent hydrogen penetration and diffusion, researchers have begun exploring methods of applying hydrogen-barrier coatings to the surface of high-strength steel. Hydrogen-barrier coatings, as a surface modification technology, aim to reduce hydrogen penetration and improve material safety and reliability by forming a protective layer with low hydrogen permeability on the material surface.

[0004] Although various hydrogen barrier coating materials and preparation technologies have been proposed, such as metal and alloy coatings, oxide coatings, and aluminide coatings, they still face some challenges in practical applications. For example, the thermal expansion coefficients of some coating materials may not match those of the substrate material, leading to cracking and peeling at high temperatures; some coatings have complex preparation processes and high costs, making industrial production difficult; and some coatings, while possessing good hydrogen barrier properties, may sacrifice other material properties, such as toughness, corrosion resistance, or bending performance. Summary of the Invention

[0005] To address the shortcomings of the existing technologies, this invention provides a 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 coating structure with a tortuous hydrogen diffusion path and a high hydrogen diffusion barrier. Through magnetron sputtering technology, the chemical composition and microstructure of the coating can be precisely controlled, achieving a tight bond between the coating and the high-strength steel substrate and excellent hydrogen-barrier performance. Furthermore, this invention optimizes the coating preparation process to adapt to different application requirements and improve the actual application effect of the coating.

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

[0007] On one hand, the present invention provides a hydrogen-resistant coating for 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 coefficient of thermal expansion of (8-20)×10⁻⁶. -6 / K, with an elastic modulus between 100-200 GPa; the hydrogen barrier coating is composed of three elements: Al, Cr, and Zr, with a molar ratio of each element not less than 30%; the hydrogen barrier coating has an amorphous structure.

[0008] Furthermore, the thickness of the hydrogen-barrier coating is 100-200 μm.

[0009] On the other hand, the present invention provides a method for preparing the above-mentioned 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 to maintain the pressure in the chamber above 1.0Pa for bias cleaning.

[0014] Furthermore, the coating process includes primary deposition and secondary deposition; the primary deposition is as follows: argon flow rate is set to 30 sccm, AlCr target power is 140-160W, 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, and deposition is carried out for 10-15 min; the secondary deposition is as follows: the Zr target power is adjusted to 140-160W, the working pressure in the chamber is 0.9-1.1Pa, and deposition is carried out for another 10-20 min.

[0015] Furthermore, in the first deposition, the power ratio of AlCr target to Zr target was 3:2; in the second deposition, the power ratio of AlCr target to Zr target was 1:1.

[0016] Compared with the prior art, the technical solution provided by the present invention brings the following beneficial effects:

[0017] (1) The present invention utilizes the significant differences in the binding energies of Al, Cr, and Zr with hydrogen. This difference is 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 the material. The amorphous AlCrZr coating lacks grain boundaries, thereby reducing the rapid diffusion channels of hydrogen and further improving the hydrogen barrier efficiency of the coating. Compared with single metal coatings, AlCrZr coatings, through the synergistic effect of multiple elements, not only improve the density and cohesion of the coating, but also enhance the adsorption and capture capacity of the coating for hydrogen, thus performing better in suppressing hydrogen permeation. The high-entropy alloy coatings in the prior art have problems such as complex inter-element interactions, difficult-to-control lattice distortion, and unpredictable hydrogen diffusion behavior caused by their multi-element composition. The AlCrZr medium-entropy alloy coating, through a carefully designed element composition, optimizes the inter-element interactions, reduces unfavorable lattice distortion, and thus provides a more stable hydrogen diffusion path.

[0018] (2) 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 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

[0019] 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.

[0020] Figure 1 Here are SEM images of the surface morphology of the hydrogen barrier coating provided in Embodiment 1 of the present invention, where a is the coating surface and b is a cross-section.

[0021] Figure 2 XRD pattern of hydrogen barrier coating provided in an embodiment of the present invention;

[0022] Figure 3 Hydrogen permeation curve of hydrogen barrier coating provided in the embodiments of the present invention. Detailed Implementation

[0023] 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.

[0024] 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.

[0025] This invention provides a hydrogen-resistant coating for the surface of high-strength steel. The high-strength steel has a hardness of HV300-HV600, a tensile strength of 900-1200 MPa, and a maximum coefficient of thermal expansion of (8-20)×10⁻⁶. -6 / K, with an elastic modulus between 100-200 GPa; the hydrogen barrier coating is composed of three elements: Al, Cr, and Zr, with a molar ratio of each element not less than 30%; the hydrogen barrier coating has an amorphous structure.

[0026] First, 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. The amorphous AlCrZr coating, lacking grain boundaries, reduces rapid hydrogen diffusion channels, further improving the coating's hydrogen barrier efficiency. Compared to single-metal coatings, AlCrZr-based coatings, through the synergistic effect of multiple elements, not only improve the coating's density and cohesion but also enhance its ability to adsorb and capture hydrogen, thus performing better in suppressing hydrogen permeation. Existing high-entropy alloy coatings, due to their multi-element composition, suffer from complex inter-element interactions, uncontrollable lattice distortion, and unpredictable hydrogen diffusion behavior. In contrast, the AlCrZr-based medium-entropy alloy coating, through a carefully designed elemental composition, optimizes inter-element interactions, reduces unfavorable lattice distortion, and thus provides a more stable hydrogen diffusion path. Secondly, regarding the high-strength steel in the existing technology, 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. -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 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.

[0027] It should be noted that the high-strength steel in this invention is 12Cr2Mo1R steel or 17-4PH.

[0028] Specifically, the thickness of the hydrogen-barrier coating is 100-200 μm. The hydrogen-barrier coating should not be too thin. While a thin coating increases manufacturing efficiency, it weakens the hydrogen-barrier performance. Furthermore, it should be noted that a thin coating lacks the elemental transition distance between itself and the high-strength steel substrate, which can easily lead to cracks between the coating and the substrate during subsequent bending processes. However, the hydrogen-barrier coating should not be too thick, as excessive thickness increases preparation time and the likelihood of cracks forming on the outer surface of the coating.

[0029] The present invention also provides a method for preparing the above-mentioned hydrogen barrier coating, comprising:

[0030] S1 selects high-strength steel and a target material, and pre-treats the surface of the high-strength steel to be coated.

[0031] 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%.

[0032] 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%.

[0033] 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 ).

[0034] 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.

[0035] S2 uses magnetron sputtering to coat the surface to be coated.

[0036] 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.

[0037] 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.

[0038] The coating process includes primary deposition and secondary deposition;

[0039] The first deposition process is as follows: argon flow rate is set to 30 sccm, AlCr target power is 140-160 W, Zr target power is 90-110 W, chamber working pressure is 0.4-0.6 Pa, substrate rotation speed is 9-11 r / min, deposition temperature is 180-220℃, the bias voltage of the magnetron sputtering equipment is adjusted to -100V, and deposition time is 10-15 min. This forms a uniform and relatively dense coating base layer. Low gas pressure helps reduce gaseous impurities in the coating, while moderate bias voltage helps improve the adhesion between the coating and the substrate, enhancing the bonding strength between the coating and the high-strength steel substrate.

[0040] The secondary deposition involves adjusting the Zr target power to 140-160 W, setting the chamber working pressure to 0.9-1.1 Pa, and then depositing for another 10-20 minutes. This increases the coating thickness to 100-200 μm to achieve the desired hydrogen barrier performance. Increasing the Zr target power and chamber pressure increases the deposition rate of Zr in the coating, while the increased pressure also contributes to the continuity of coating growth, resulting in a thicker coating. Furthermore, the above process parameters ensure that the molar ratio of each element is not less than 30%.

[0041] Preferably, in the first deposition, the power ratio of AlCr target to Zr target is 3:2; in the second deposition, the power ratio of AlCr target to Zr target is 1:1.

[0042] In this embodiment of the invention, the performance of the prepared hydrogen-barrier coating is tested, including:

[0043] 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).

[0044] 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.

[0045] Example 1

[0046] This invention provides a method for preparing a hydrogen-barrier coating on a high-strength steel surface, comprising:

[0047] S1 selects high-strength steel and a target material, and pre-treats the surface of the high-strength steel to be coated.

[0048] Using 12Cr2Mo1R steel and a target material, the surface of the 12Cr2Mo1R steel to be coated is polished and cleaned.

[0049] S2 uses magnetron sputtering to coat the surface to be coated.

[0050] 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.

[0051] 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.

[0052] The coating process was as follows: Argon flow rate was set to 30 sccm, AlCr target power to 150 W, Zr target power to 100 W, chamber working pressure to 0.5 Pa, substrate rotation speed to 10 r / min, deposition temperature to 200℃, and the bias voltage of the magnetron sputtering equipment to -100 V. Deposition was carried out for 10 min. Then, the Zr target power was adjusted to 150 W, chamber working pressure to 1.0 Pa, and deposition was carried out for another 10 min. The morphology of the prepared hydrogen-barrier coating is shown in the figure below. Figure 1 As shown in 1a and 1b, the thickness of the prepared hydrogen barrier coating is 141 μm.

[0053] like Figure 2 "-100V", "-150V", and "-50V" represent the bias voltage of the magnetron sputtering equipment, indicating that the prepared coating has an amorphous structure; for example... Figure 3 As shown, the osmotic current density was measured to be 0.68 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 hydrogen-resistant coating and the 12Cr2Mo1R steel substrate.

[0054] Example 2

[0055] This invention provides a method for preparing a hydrogen-barrier coating on a high-strength steel surface, comprising:

[0056] S1 selects high-strength steel and a target material, and pre-treats the surface of the high-strength steel to be coated.

[0057] Using 12Cr2Mo1R steel and a target material, the surface of the 12Cr2Mo1R steel to be coated is polished and cleaned.

[0058] S2 uses magnetron sputtering to coat the surface to be coated.

[0059] 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.

[0060] The bias cleaning process is as follows: 12Cr2Mo1R steel is heated and cleaned under bias. The preparation temperature is set to 180℃ 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.

[0061] The coating process was as follows: the argon flow rate was set to 30 sccm, the AlCr target power was 140 W, the Zr target power was 90 W, the working pressure in the chamber was 0.4 Pa, the substrate rotation speed was 9 r / min, the deposition temperature was 180 ℃, the bias voltage of the magnetron sputtering equipment was adjusted to -100 V, and deposition was carried out for 10 min; then the Zr target power was adjusted to 140 W, the working pressure in the chamber was 1.0 Pa, and deposition was carried out for another 10 min. The thickness of the hydrogen barrier coating was 101 μm.

[0062] The prepared coating has an amorphous structure; the measured permeation current density is 0.74 μA·cm. -2 Mechanical performance testing showed that when the thickness of the high-strength steel was 5mm, the minimum bending radius was 2cm, and there were no cracks at the interface between the hydrogen-resistant coating and the 12Cr2Mo1R steel substrate.

[0063] Example 3

[0064] This invention provides a method for preparing a hydrogen-barrier coating on a high-strength steel surface, comprising:

[0065] S1 selects high-strength steel and a target material, and pre-treats the surface of the high-strength steel to be coated.

[0066] Using 12Cr2Mo1R steel and a target material, the surface of the 12Cr2Mo1R steel to be coated is polished and cleaned.

[0067] S2 uses magnetron sputtering to coat the surface to be coated.

[0068] 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.

[0069] 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.

[0070] The coating process was as follows: the argon flow rate was set to 30 sccm, the AlCr target power was 160 W, the Zr target power was 110 W, the working pressure in the chamber was 0.6 Pa, the substrate rotation speed was 11 r / min, the deposition temperature was 220℃, the bias voltage of the magnetron sputtering equipment was adjusted to -100 V, and deposition was carried out for 15 min; then the Zr target power was adjusted to 160 W, the working pressure in the chamber was 1.1 Pa, and deposition was carried out for another 20 min. The thickness of the hydrogen barrier coating was 198 μm.

[0071] The prepared coating has an amorphous structure; the measured permeation current density is 0.87 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 hydrogen-resistant coating and the 12Cr2Mo1R steel substrate.

[0072] Example 4

[0073] This invention provides a method for preparing a hydrogen-barrier coating on a high-strength steel surface, comprising:

[0074] S1 selects high-strength steel and a target material, and pre-treats the surface of the high-strength steel to be coated.

[0075] Using 17-4PH steel and a target material, the surface of the 17-4PH steel to be coated is polished and cleaned.

[0076] S2 uses magnetron sputtering to coat the surface to be coated.

[0077] 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.

[0078] The bias cleaning process is as follows: 17-4PH steel is heated and cleaned under bias. The preparation temperature is set to 200℃ to begin heating the 17-4PH steel. When the predetermined temperature is reached and the vacuum level inside the chamber is 1.8 × 10⁻⁶, the cleaning continues. -3 When 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 keep the pressure in the chamber above 1.0Pa for bias cleaning. First, bombard the 17-4PH steel surface with Ar+ particles for 10 minutes to ensure that the contaminants on the 17-4PH steel surface can be removed, the 17-4PH steel surface can be activated, and the adhesion of the coating can be guaranteed.

[0079] The coating process was as follows: the argon flow rate was set to 30 sccm, the AlCr target power was 150 W, the Zr target power was 100 W, the working pressure in the chamber was 0.5 Pa, the substrate rotation speed was 10 r / min, the deposition temperature was 200 ℃, the bias voltage of the magnetron sputtering equipment was adjusted to -100 V, and deposition was carried out for 10 min; then the Zr target power was adjusted to 150 W, the working pressure in the chamber was 1.0 Pa, and deposition was carried out for another 10 min. The thickness of the hydrogen barrier coating was 143 μm.

[0080] The prepared coating has an amorphous structure; the measured permeation current density is 0.64 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 hydrogen-resistant coating and the 12Cr2Mo1R steel substrate.

[0081] Comparative Example 1

[0082] Unlike Example 1, in step S2 of this comparative example, the AlCr target power is 150W, the Zr target power is 100W, and the deposition time is 20 minutes.

[0083] 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 10 cm, cracks exist at the interface between the hydrogen barrier coating and the 12Cr2Mo1R steel substrate.

[0084] Comparative Example 2

[0085] Unlike Example 1, in step S2 of this comparative example, the AlCr target power was 150W, the Zr target power was 150W, and the deposition time was 20 minutes.

[0086] 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 15 cm, cracks exist at the interface between the hydrogen barrier coating and the 12Cr2Mo1R steel substrate.

[0087] Comparative Example 3

[0088] Unlike Example 1, in step S2 of this comparative example, the time for the first deposition is 8 minutes, and the time for the second deposition is 12 minutes.

[0089] 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, cracks exist on the outer surface of the hydrogen barrier coating.

[0090] Comparative Example 4

[0091] Unlike Example 1, in step S2 of this comparative example, the time for the first deposition is 12 minutes, and the time for the second deposition is 8 minutes.

[0092] The prepared coating has an amorphous structure; the measured permeation current density is 2.47 μA·cm. -2 .

[0093] Comparative Example 3

[0094] Unlike Example 1, in S2 of this comparative example, the bias voltage of the magnetron sputtering equipment is -50V. For example... Figure 3 As shown, its osmotic current density was measured to be 3.40 μA·cm. -2 .

[0095] Comparative Example 4

[0096] Unlike Example 1, in S2 of this comparative example, the bias voltage of the magnetron sputtering equipment is -150V. For example... Figure 3 As shown, its osmotic current density was measured to be 1.20 μA·cm. -2 .

[0097] 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 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 hydrogen barrier coating is composed of three elements: Al, Cr, and Zr, with each element having a molar ratio of not less than 30%. The hydrogen-barrier coating has an amorphous structure; The method for preparing the hydrogen-barrier coating includes: 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. The coating process includes primary deposition and secondary deposition; The first deposition was performed as follows: argon flow rate was set to 30 sccm, AlCr target power was 140-160 W, Zr target power was 90-110 W, chamber working pressure was 0.4-0.6 Pa, substrate rotation speed was 9-11 r / min, deposition temperature was 180-220℃, the bias voltage of the magnetron sputtering equipment was adjusted to -100 V, and deposition time was 10-15 min. The secondary deposition involves adjusting the Zr target power to 140-160W, setting the working pressure in the chamber to 0.9-1.1Pa, and then depositing for 10-20 minutes.

2. The hydrogen-barrier coating according to claim 1, characterized in that, The thickness of the hydrogen barrier coating is 100-200 μm.

3. The hydrogen-barrier coating according to claim 1, characterized in that, The target materials include AlCr targets and Zr targets.

4. The hydrogen-barrier coating according to claim 1, 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.

5. The hydrogen-barrier coating according to claim 1, characterized in that, The magnetron sputtering process includes vacuuming, bias cleaning, and coating. The vacuum level after evacuation is no greater than 2.0 × 10⁻⁶. -3 Pa.

6. The hydrogen-barrier coating according to claim 5, 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 to maintain the pressure in the chamber above 1.0Pa for bias cleaning.

7. The hydrogen-barrier coating according to claim 6, characterized in that, In a single deposition, the power ratio of the AlCr target to the Zr target was 3:2; In the secondary deposition, the power ratio of the AlCr target to the Zr target was 1:1.

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