CN-122013102-A - Composite hydrogen-resistant coating of high-strength maraging stainless steel and preparation method thereof

Abstract

The invention discloses a composite hydrogen-resistant coating of high-strength maraging stainless steel and a preparation method thereof, belonging to the field of surface modification of metal materials. The method comprises the steps of preprocessing a matrix, and then sequentially carrying out bias cleaning, cu layer deposition and AlN layer deposition to obtain the Cu/AlN composite hydrogen-resistant coating. According to the invention, through the synergistic effect of the Cu layer and the AlN layer, the binding force between the coating and the matrix is obviously enhanced, the coating spalling and microcracking caused by thermal stress are avoided, and meanwhile, a high-efficiency hydrogen diffusion barrier is formed. The method has the advantages of simple process and low cost, and the hydrogen embrittlement resistance of the high-strength maraging stainless steel is obviously improved after the coating is plated, so that the method is suitable for long-acting protection of the high-strength maraging stainless steel in a hydrogen-rich environment.

Inventors

• Tan Linhao
• BAI QINGQING
• SHENG ZHENDONG
• WU ZHIWEI

Assignees

• 成都先进金属材料产业技术研究院股份有限公司

Dates

Publication Date

20260512

Application Date

20260410

Claims (10)

1. 1. The preparation method of the composite hydrogen-resistant coating of the high-strength maraging stainless steel is characterized by comprising the following steps of: S1, sequentially polishing, cleaning and drying a high-strength maraging stainless steel substrate; S2, placing the substrate treated in the step S1 in physical vapor deposition equipment, carrying out bias cleaning, and then carrying out film plating treatment to obtain the high-strength maraging stainless steel plated with the Cu/AlN composite hydrogen-resistant coating; The method comprises the steps of depositing a Cu layer by utilizing a Cu target under the conditions of a cavity temperature of 200-300 ℃ and an argon flow of 20-23 sccm, wherein the deposition time is 8-10 min, and the deposition thickness is 50-60 mu m, and then depositing an AlN layer by utilizing an AlN target under the conditions of a cavity temperature of 200-300 ℃ and an argon flow of 30-35 sccm, wherein the deposition time is 15-20 min, and the deposition thickness is 150-170 mu m, so that the Cu/AlN composite hydrogen-resistant coating is finally obtained.
2. 2. The preparation method according to claim 1, wherein in the step S1, the chemical components of the high-strength maraging stainless steel substrate are, in mass percent, C is less than or equal to 0.02%, 12.00% is less than or equal to 13.00%, 8.50% is less than or equal to 9.50% Ni, 3.50% is less than or equal to 5.00% Co, 2.00% is less than or equal to 3.00% Mo, 0.30% is less than or equal to 0.60% Al, and the balance is Fe and unavoidable impurities.
3. 3. The method according to claim 1, wherein in the step S1, the yield strength of the high-strength maraging stainless steel substrate after solution treatment and peak aging treatment is 1500-160 MPa.
4. 4. The method according to claim 1, wherein in the step S1, the polishing is performed by sequentially using 400# SiC sandpaper, 800# SiC sandpaper, 1200# SiC sandpaper, 2000# SiC sandpaper and 5000# SiC sandpaper, and the scratches of the next sandpaper completely cover the scratches of the previous sandpaper.
5. 5. The method according to claim 1, wherein in step S1, the polishing is performed mechanically using a diamond polishing paste having a particle size of 1.5 μm until the surface of the substrate is free of scratches and exhibits a mirror surface.
6. 6. The preparation method according to claim 1, wherein in the step S1, the cleaning and drying treatment is specifically that an alcohol solution is adopted for ultrasonic vibration cleaning for 10-20 min, and then hot air is used for drying for 5-10min, so that no stains on the polished surface are ensured.
7. 7. The preparation method of the vacuum cleaning device according to claim 1 is characterized in that in the step S2, the temperature of the cavity is set to be 200-300 ℃, vacuum is pumped until the vacuum degree in the cavity is less than or equal to 1.0 multiplied by 10 -3 Pa, then a stop valve is opened, the opening degree of a flow limiting valve is set to be 85 degrees, the flow rate of argon is set to be 20sccm, the bias is set to be-300V, the pressure in the cavity is kept to be more than 1.0Pa, and the cleaning time is not less than 20min.
8. 8. The method according to claim 1, wherein in step S2, during the film plating process: When a Cu layer is deposited, the power of a Cu target is 150-180W, the vacuum degree is kept at 0.3-0.5 Pa, and the rotating speed of a substrate is 5-8 r/min; when the AlN layer is deposited, the AlN target power is 220-250W, the vacuum degree is kept at 0.1-0.3 Pa, and the substrate rotating speed is 5-8 r/min.
9. 9. A high strength maraging stainless steel coated with a Cu/AlN composite hydrogen barrier coating, produced by the production method as claimed in any one of claims 1 to 8.
10. 10. The high strength maraging stainless steel as recited in claim 9, wherein the hydrogen diffusion coefficient of the high strength maraging stainless steel is (1.17-2.45). Times.10 -9 cm 2 /s.

Description

Composite hydrogen-resistant coating of high-strength maraging stainless steel and preparation method thereof Technical Field The invention belongs to the field of metal material surface modification, and particularly relates to a composite hydrogen-resistant coating of high-strength maraging stainless steel and a preparation method thereof. Background In the process of converting the global energy structure into low carbonization, hydrogen energy has become a research and application hotspot in the energy field by virtue of the advantages of cleanliness and high efficiency. The metal material is a core structural material in a hydrogen energy storage, transportation and application system, and the service safety and reliability of the metal material directly determine the stable operation of related equipment. However, metallic materials are very prone to hydrogen embrittlement failure in a hydrogen environment, and when the hydrogen content in the incoming material reaches a certain threshold, the material suffers a serious loss of strength or toughness under the dual action of hydrogen and stress, which is called hydrogen embrittlement. The higher the strength of the metal material, the higher the hydrogen embrittlement sensitivity thereof, and the generation of hydrogen embrittlement has become one of the main bottlenecks restricting the application of the high-end metal material. At present, the high-efficiency prevention and control path for the high-strength steel hydrogen embrittlement problem is mainly divided into two types, namely, a physical barrier is constructed by coating a protective coating to block the channel of external hydrogen atoms which invade a material matrix, and a stable hydrogen trap site is constructed by regulating and optimizing the microstructure of the material to realize the high-efficiency capture of the invaded hydrogen. The coating method has the advantages of direct protection, wide applicability, strong stability and convenient maintenance, and shows better engineering application prospect in the prevention and control of hydrogen embrittlement of high-strength steel However, the existing hydrogen-resistant coating technology is mostly developed for ordinary carbon steel or low alloy steel, for example, CN117802458a discloses a carbon steel surface composite nitride hydrogen-resistant coating, which adopts a CrN, tiN, alN multi-layer nitride structure, but the bonding strength of the coating and a metal matrix is weaker, and the specific object is ordinary carbon steel, the strength is lower, and the risk of hydrogen embrittlement is far lower than that of high-strength maraging stainless steel. In another example, CN119040828a discloses a composite hydrogen-resistant coating on the surface of high-strength steel, and the amorphous structure is formed by oxides formed by Al, cr and Zr. Although the coating has a certain hydrogen resistance effect, the thermal expansion coefficient difference between the coating and the high-strength maraging stainless steel matrix is large, and under the working condition of temperature cycling, repeated thermal stress can be generated at the interface between the coating and the matrix, so that the peeling and failure of the coating are accelerated. For maraging stainless steel with yield strength of more than 1500MPa, the maraging stainless steel has multiple alloy element types, complex microstructure, high surface energy and easy formation of passivation film, so that the combination of the coating and the matrix is more difficult. The existing coating system often has the problems of insufficient bonding strength, easy cracking and falling off and the like on the ultrahigh-strength matrix, and is difficult to exert an effective hydrogen blocking effect. Meanwhile, high-strength maraging stainless steel is extremely sensitive to hydrogen embrittlement, and even a trace amount of hydrogen permeation can cause remarkable reduction of mechanical properties, so that higher requirements are put on compactness and hydrogen blocking efficiency of a coating. Therefore, how to develop a coating which is firmly combined with a high-strength maraging stainless steel substrate, has good heat matching and has excellent hydrogen resistance, and the technical problem to be solved in the field is urgent. Disclosure of Invention The invention aims to solve the technical problems that the existing hydrogen-resistant coating has insufficient binding force with a high-strength maraging stainless steel substrate and a stable and defect-free hydrogen-resistant protective layer is difficult to form on the surface of the substrate. The technical scheme adopted for solving the technical problems is as follows: in a first aspect, the invention provides a method for preparing a composite hydrogen-resistant coating of high-strength maraging stainless steel, comprising the following steps: S1, sequentially polishing, cleaning and drying a high-strength maragi