Composite organic hydrogen barrier coating for stainless steel and method of manufacture

Abstract

The present application relates to the technical field of organic coating, in particular to a composite organic hydrogen barrier coating for stainless steel and a preparation method, the organic coating has excellent hydrogen barrier effect, meets the demand of stainless steel material for hydrogen barrier, the chemical composition of the organic hydrogen barrier coating comprises: epoxy resin: 40.5-43.4%, curing agent: 28.9-32.9%, diluent: 19.2-24.8%, MoSe2: 3.63-4.13%, silane modified graphene: 0.21-0.64%, Ti3AlC2: 0.46-1.07%, and the sum of the mass percentages of the chemical components is 100%. The prepared organic hydrogen barrier coating has reasonable chemical composition, good hydrogen barrier effect, simple manufacturing method, easy production, significant production advantages and application value, and significant social benefits.

Description

Technical Field

[0001] This invention relates to the field of organic coating technology, specifically to a composite organic hydrogen barrier coating for stainless steel and its preparation method. Background Technology

[0002] Hydrogen energy, as a clean and green energy source, has advantages such as being pollution-free, having a high calorific value, and being renewable and recyclable. It is hailed as the secondary energy source with the greatest development potential in the future. However, the problem of hydrogen damage in hydrogen energy storage and transportation materials is one of the key challenges currently hindering the industrialization of hydrogen energy. This is because when metal materials are used in high-pressure, hydrogen-rich environments for extended periods, hydrogen inevitably enters the interior of the materials through permeation and diffusion, making the materials prone to hydrogen embrittlement and hydrogen damage. This seriously affects the stable operation of hydrogen storage and transportation systems and can even lead to serious safety accidents, causing irreparable losses to people's lives and property.

[0003] Due to its excellent corrosion resistance and mechanical properties, 316L stainless steel is widely used in hydrogen storage equipment, reactor blanket structures and other fields. In order to mitigate the corrosion and damage of hydrogen and its isotopes to austenitic stainless steel, a hydrogen-blocking coating is generally prepared on the material surface to set up a hydrogen permeation barrier, which can slow down or prevent hydrogen and its isotopes from entering the substrate, thereby preventing hydrogen embrittlement and other phenomena. This is currently a relatively economical and effective method.

[0004] Currently, the hydrogen barrier coatings used on a large scale are mainly ceramic coatings, including oxide coatings (Er2O3, Al2O3, ZrO2, SiO2, TiO2, Cr2O3, etc.) and non-oxidizing coatings (TiN, Fe2N, AlN, TiC, SiC, etc.). They have good hydrogen barrier properties and are mainly prepared by magnetron sputtering, chemical vapor deposition, micro-arc oxidation, plasma spraying, sol-gel method, etc. However, their preparation processes are often complex and demanding, and they are not easy to apply on a large scale to pipes and irregular parts. In addition, this type of hydrogen barrier coating and substrate material also have problems such as low bonding, poor thermal shock resistance, and easy cracking and peeling.

[0005] With the development of new materials and processes, organic hydrogen barrier coatings have attracted increasing attention due to their excellent corrosion resistance, ideal mechanical properties, and simple construction process. However, there is relatively little research and application of organic hydrogen barrier coatings in China, and existing organic hydrogen barrier coatings still have problems that need to be solved, such as the relatively simple chemical composition of hydrogen barrier coatings and the unsatisfactory hydrogen barrier effect. Summary of the Invention

[0006] To address the aforementioned defects and problems, this invention provides a composite organic hydrogen barrier coating for stainless steel and its preparation method. The formulation is reasonable, the preparation process is simple, and the hydrogen barrier effect is good. It can be applied to the surface of 316L stainless steel as an organic hydrogen barrier coating.

[0007] The solution adopted by this invention to solve its technical problem is: a composite organic hydrogen barrier coating for stainless steel, wherein the chemical composition of the composite organic hydrogen barrier coating is as follows (by mass percentage): epoxy resin: 40.5-43.4%, curing agent: 28.9-32.9%, diluent: 19.2-24.8%, MoSe2: 3.63-4.13%, silane-modified graphene: 0.21-0.64%, and Ti3AlC2: 0.46-1.07%, with the sum of the mass percentages of each chemical component being 100%.

[0008] Furthermore, the curing agent is polyamide 650, and the diluent is a mixed solvent composed of xylene and n-butanol, with the mass ratio of xylene to n-butanol being (6-7):(3-4) or 7:3.

[0009] Furthermore, the epoxy resin is a bisphenol A type epoxy resin, the NbSe2 is nano NbSe2, and the Ti2SnC is nano Ti2SnC.

[0010] Furthermore, the bisphenol A type epoxy resin can be one of Baling Petrochemical E44, Phoenix 6101, Nanya 128, and Sanmu 828.

[0011] Furthermore, the chemical composition of the composite organic hydrogen barrier coating is as follows by mass percentage: epoxy resin: 42.2%, curing agent: 29.5%, diluent: 23.2%, MoSe2: 3.8%, silane-modified graphene: 0.45%, Ti3AlC2: 0.85%, and the sum of the mass percentages of each chemical component is 100%.

[0012] Furthermore, a method for preparing a composite organic hydrogen-barrier coating for stainless steel, characterized by the application of such a coating, comprises the following steps: (1) Pretreatment of 316L stainless steel material: Grind the base material with sandpaper or grinding wheel to remove oxide scale, grease, etc. until the metal luster is exposed. Then remove surface oil and impurities with anhydrous ethanol or acetone, then wash with hot water and rinse with running water, and finally dry with hot air. (2) Prepare the diluent according to the proportion, and then add silane-modified graphene, MoSe2 and Ti3AlC2 into the diluent. Use a magnetic stirrer to stir at 500-800 rpm for 15-30 min. After thorough mixing, obtain solution A. (3) Add the epoxy resin weighed in proportion to solution A, and stir with a magnetic stirrer at a speed of 800-1100 rpm for 20-40 minutes until fully mixed to obtain solution B; (4) Add the weighed curing agent to solution B and stir with a magnetic stirrer at a speed of 500-750 rpm for 2-3 hours until the mixture is homogeneous. (5) Apply the mixed solution B to the surface of 316L stainless steel material, then let it air dry naturally for 12-18 hours, and then put it into a vacuum drying oven at 50-65℃ for 24-30 hours. After taking it out, let it cure naturally at room temperature to obtain the composite organic hydrogen barrier coating.

[0013] Furthermore, the thickness of the prepared composite organic hydrogen barrier coating is 0.10–0.30 mm.

[0014] Furthermore, when preparing the diluent, the stirring speed was 700 rpm, and the stirring time was 20 minutes.

[0015] The beneficial effects of this invention: The composite organic hydrogen barrier coating of this invention not only bonds firmly to the surface of 316L stainless steel, but also has a dense coating structure, low gas permeability, and excellent hydrogen barrier effect. This is largely due to the silane-modified graphene, MoSe2, and Ti3AlC2 introduced into the coating. The combined effect of these three substances can effectively improve the hydrogen barrier effect of the organic coating: First, the nanoscale layered structure of silane-modified graphene can directly block hydrogen permeation and also acts as a good hydrogen trap, thus blocking hydrogen permeation; second, MoSe2 and Ti3AlC2 possess unique nanolayered structures... The crystalline structure can hinder the diffusion of hydrogen in the coating, thus improving its hydrogen barrier performance. Third, silane-modified graphene can also improve the crystallinity and density of epoxy resin, reducing defects in the epoxy resin coating, thereby enhancing the bonding strength between the organic hydrogen barrier coating and 316L stainless steel and improving the hydrogen barrier effect of the coating. Through the strong bonding between the composite organic hydrogen barrier coating and 316L stainless steel, and the dense coating structure, hydrogen damage to 316L stainless steel can be effectively mitigated or even prevented. Furthermore, the organic hydrogen barrier coating has a scientifically formulated chemical composition, low cost, and a simple and easy-to-implement preparation method, exhibiting significant production advantages and social benefits. Attached Figure Description

[0016] Figure 1 This is a morphology diagram of the unmodified graphene used in this invention.

[0017] Figure 2 This is a morphology diagram of the silane-modified graphene prepared in this invention.

[0018] Figure 3The image shows the morphological characteristics of the composite organic hydrogen barrier coating for stainless steel prepared according to the present invention during an adhesion test. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Example 1: In a specific implementation of the present invention, the chemical composition of the composite organic hydrogen barrier coating is as follows by mass percentage: epoxy resin (Baling Petrochemical E44): 42.2%, curing agent (polyamide 650): 29.5%, diluent: 23.2%, MoSe2: 3.8%, silane-modified graphene: 0.36%, Ti3AlC2: 0.94%, and the sum of the mass percentages of each chemical component is 100%.

[0021] The diluent is a mixed solvent composed of xylene and n-butanol, and the mass ratio of xylene to n-butanol is 7:3.

[0022] Its preparation method includes the following steps: (1) Pretreatment of 316L stainless steel material: The base material is polished with 400#, 600#, 800# and 1000# sandpaper in sequence to remove oxide scale, grease and other substances until the metal luster is exposed. Then, the surface oil and impurities are removed with anhydrous ethanol, and then the material is cleaned with hot water and rinsed with running water. Finally, it is dried with a hot air blower. (2) Prepare the diluent according to the proportion, and then add silane-modified graphene, MoSe2 and Ti3AlC2 into the diluent. Stir with a magnetic stirrer at 500 rpm for 20 min. After thorough mixing, obtain solution A. (3) Weigh the epoxy resin (Baling Petrochemical E44) according to the proportion and add it to solution A. Use a magnetic stirrer to stir at 800 rpm for 35 minutes. After thorough mixing, solution B is obtained. (4) Add the weighed curing agent (polyamide 650) to solution B and stir at 700 rpm for 2 hours using a magnetic stirrer until the mixture is homogeneous. (5) Apply the mixed solution B to the surface of 316L stainless steel material with a coating thickness of 0.2mm, then let it air dry naturally for 12 hours, and then put it into a vacuum drying oven at 60℃ for 24 hours. After taking it out, let it cure naturally at room temperature. After trimming, the composite organic hydrogen barrier coating can be obtained.

[0023] The composite organic hydrogen barrier coating provided in this embodiment has a strong bond with 316L stainless steel and a dense coating structure, which can effectively reduce or even prevent hydrogen damage to 316L stainless steel. At the same time, the chemical composition of this organic hydrogen barrier coating is scientific, the cost is low, the preparation method is simple and easy to implement, and it has significant production advantages and social benefits.

[0024] Example 2, in this embodiment, a composite organic hydrogen barrier coating for stainless steel and its preparation method are described, focusing on the differences from those in Example 1.

[0025] In this embodiment, the chemical composition of the composite organic hydrogen barrier coating is as follows by mass percentage: epoxy resin (Nanya 128): 41.5%, curing agent (polyamide 650): 31.9%, diluent: 21.3%, MoSe2: 4.03%, silane-modified graphene: 0.55%, Ti3AlC2: 0.72%, and the sum of the mass percentages of each chemical component is 100%.

[0026] The diluent is a mixed solvent composed of xylene and n-butanol, and the mass ratio of xylene to n-butanol is 7:3.

[0027] Its preparation method includes the following steps: (1) Pretreatment of 316L stainless steel material: The base material is polished with 400#, 600#, 800# and 1000# sandpaper in sequence to remove oxide scale, grease and other substances until the metal luster is exposed. Then, the surface oil and impurities are removed with anhydrous ethanol or acetone. Then, it is cleaned with hot water and rinsed with running water. Finally, it is dried with a hot air blower. (2) Prepare the diluent according to the proportion, and then add silane-modified graphene, MoSe2 and Ti3AlC2 into the diluent. Stir with a magnetic stirrer at 600 rpm for 18 minutes. After thorough mixing, obtain solution A. (3) Add the epoxy resin (Nanya 128) weighed according to the proportion to solution A, and stir with a magnetic stirrer at 900 rpm for 30 minutes. After thorough mixing, solution B is obtained. (4) Add the weighed curing agent (polyamide 650) to solution B and stir at 600 rpm for 2.5 hours using a magnetic stirrer until the mixture is homogeneous. (5) Apply the mixed solution B to the surface of 316L stainless steel material with a coating thickness of 0.25mm, then let it air dry naturally for 14 hours, and then put it into a vacuum drying oven at 58℃ for 26 hours. After taking it out, let it cure naturally at room temperature. After trimming, the composite organic hydrogen barrier coating can be obtained.

[0028] Example 3 describes a composite organic hydrogen barrier coating for stainless steel and its preparation method, focusing on the differences from those in Example 1.

[0029] In this embodiment, the chemical composition of the composite organic hydrogen barrier coating is as follows by mass percentage: epoxy resin (Sanmu 828): 41.8%, curing agent (polyamide 650): 29.0%, diluent: 24.2%, MoSe2: 3.96%, silane-modified graphene: 0.42%, Ti3AlC2: 0.62%, and the sum of the mass percentages of each chemical component is 100%.

[0030] The diluent is a mixed solvent composed of xylene and n-butanol, and the mass ratio of xylene to n-butanol is 7:3.

[0031] Its preparation method includes the following steps: (1) Pretreatment of 316L stainless steel material: The base material is polished in sequence with 400#, 600#, 800# and 1000# sandpaper to remove oxide scale, grease and other substances until the metal luster is exposed. Then, acetone is used to remove surface oil and impurities. Then, hot water is used to clean and rinsed with running water. Finally, it is dried with a hot air blower. (2) Prepare the diluent according to the proportion, and then add silane-modified graphene, MoSe2 and Ti3AlC2 into the diluent. Use a magnetic stirrer to stir at 750 rpm for 25 min. After thorough mixing, obtain solution A. (3) Add the epoxy resin (Sanmu 828) weighed according to the proportion to solution A, and stir with a magnetic stirrer at 1000 rpm for 35 minutes. After thorough mixing, solution B is obtained. (4) Add the weighed curing agent (polyamide 650) to solution B and stir at 750 rpm for 3 hours using a magnetic stirrer until the mixture is homogeneous. (5) Apply the mixed solution B to the surface of 316L stainless steel material with a coating thickness of 0.30mm, then let it air dry naturally for 16h, and then put it into a vacuum drying oven at 60℃ for 30h. After taking it out, let it cure naturally at room temperature. After trimming, the composite organic hydrogen barrier coating can be obtained.

[0032] Performance testing: Electrochemical hydrogen permeation experiments were conducted on the composite organic hydrogen barrier coatings prepared in Examples 1-3 above at room temperature. The results are as follows: 1. The composite organic hydrogen-blocking coating prepared according to the formulation and method described in Example 1 has a hydrogen permeation blocking capacity 83 times that of 316L stainless steel. The coating exhibits excellent hydrogen blocking effect, and the surface condition of the organic coating is good after electrochemical hydrogen permeation experiments, showing a strong bond with the 316L stainless steel. Furthermore, the adhesion strength test of the organic coating using a cross-cut adhesion tester shows that the organic hydrogen-blocking coating and the 316L stainless steel are tightly bonded, meeting the ISO Class 0 and ASTM Class 5B standards. 2. The composite organic hydrogen-blocking coating prepared according to the formulation and method described in Example 2 has a hydrogen permeation blocking capacity 90 times that of 316L stainless steel. The coating exhibits excellent hydrogen blocking effect, and the surface condition of the organic coating is good after electrochemical hydrogen permeation experiments, showing a strong bond with the 316L stainless steel. Furthermore, the adhesion strength test of the organic coating using a cross-cut adhesion tester shows that the organic hydrogen-blocking coating and the 316L stainless steel substrate are tightly bonded, meeting the ISO grade 0 and ASTM grade 5B standards. 3. The composite organic hydrogen-blocking coating prepared according to the formulation and method described in Example 3 has a hydrogen permeation blocking capacity 87 times that of 316L stainless steel. The coating exhibits excellent hydrogen blocking effect, and the surface condition of the organic coating is good after electrochemical hydrogen permeation experiments, showing a strong bond with the 316L stainless steel. Furthermore, the adhesion strength test of the organic coating using a cross-cut adhesion tester shows that the organic hydrogen-blocking coating and the 316L stainless steel substrate are tightly bonded, meeting the ISO Class 0 and ASTM Class 5B standards. Using the composite organic hydrogen-barrier coating for stainless steel and its preparation method described in this invention, organic hydrogen-barrier coatings were repeatedly prepared on 316L stainless steel materials, and relevant performance tests were conducted on the composite organic hydrogen-barrier coatings. Similar or identical experimental results were obtained in all cases. These experimental results demonstrate that the composite organic hydrogen-barrier coating for stainless steel described in this invention can effectively reduce hydrogen penetration into 316L stainless steel materials, thereby mitigating or even preventing hydrogen damage to 316L stainless steel materials, improving the safety and reliability of materials in hydrogen storage and transportation equipment, and increasing the service life of 316L stainless steel materials by 5 to 10 times compared to the original method. This significantly reduces economic losses caused by hydrogen damage to materials and lowers the operating costs of enterprises.

[0033] In summary, the composite organic hydrogen barrier coating for stainless steel provided by this invention has good hydrogen barrier effect, reasonable formulation, low preparation cost, simple preparation process, and is easy to implement. It has significant production advantages and social benefits, and is an innovation in the design and application of organic hydrogen barrier coatings.

[0034] The above description is only a preferred embodiment of the present invention and does not limit the present invention. Any modifications, equivalent substitutions and improvements 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 organic hydrogen-barrier coating for stainless steel, characterized in that, The composite organic hydrogen barrier coating has the following chemical composition by mass percentage: epoxy resin: 40.5–43.4%, curing agent: 28.9–32.9%, diluent: 19.2–24.8%, MoSe2: 3.63–4.13%, silane-modified graphene: 0.21–0.64%, Ti3AlC2: 0.46–1.07%, the sum of the mass percentages of all chemical components totals 100%; The combined effect of the silane-modified graphene, MoSe2, and Ti3AlC2 is as follows: The silane-modified graphene utilizes its nanosheet structure as a direct physical barrier to hydrogen permeation and acts as a hydrogen trap. The MoSe2 and Ti3AlC2 utilize their respective nanolayered crystal structures to hinder the diffusion of hydrogen in the coating; The silane-modified graphene is also used to improve the crystallinity and density of epoxy resin to reduce coating defects. The curing agent is polyamide 650, and the diluent is a mixed solvent composed of xylene and n-butanol, with a mass ratio of xylene to n-butanol of (6-7):(3-4). The epoxy resin is a bisphenol A type epoxy resin, MoSe2 is nano MoSe2, and Ti3AlC2 is nano Ti3AlC2.

2. The composite organic hydrogen-barrier coating for stainless steel according to claim 1, characterized in that, The bisphenol A type epoxy resin is one of Baling Petrochemical E44, Phoenix 6101, Nanya 128, and Sanmu 828.

3. The composite organic hydrogen-barrier coating for stainless steel according to claim 1, characterized in that, The composite organic hydrogen barrier coating has the following chemical composition by mass percentage: epoxy resin: 42.2%, curing agent: 29.5%, diluent: 23.2%, MoSe2: 3.8%, silane-modified graphene: 0.45%, Ti3AlC2: 0.85%, the sum of the mass percentages of all chemical components is 100%.

4. A method for preparing a composite organic hydrogen barrier coating for stainless steel, comprising applying the composite organic hydrogen barrier coating for stainless steel described in any one of claims 1-3, characterized in that, Includes the following steps: (1) Pretreatment of 316L stainless steel material: Grind the base material with sandpaper or grinding wheel to remove oxide scale and grease until the metal luster is exposed. Then remove surface oil and impurities with anhydrous ethanol or acetone, then wash with hot water and rinse with running water, and finally dry with hot air. (2) Prepare the diluent according to the proportion, and then add silane-modified graphene, MoSe2 and Ti3AlC2 into the diluent. Use a magnetic stirrer to stir at 500-800 rpm for 15-30 min. After thorough mixing, obtain solution A. (3) Add the epoxy resin weighed in proportion to solution A, and stir with a magnetic stirrer at a speed of 800-1100 rpm for 20-40 minutes until fully mixed to obtain solution B; (4) Add the weighed curing agent to solution B and stir with a magnetic stirrer at a speed of 500-750 rpm for 2-3 hours until the mixture is homogeneous. (5) Apply the well-mixed solution to the surface of 316L stainless steel material, then let it air dry naturally for 12-18 hours, and then put it into a vacuum drying oven at 50-65℃ for 24-30 hours. After taking it out, let it cure naturally at room temperature to obtain the composite organic hydrogen barrier coating.

5. The method for preparing a composite organic hydrogen-barrier coating for stainless steel according to claim 4, characterized in that, The thickness of the prepared composite organic hydrogen barrier coating is 0.10–0.30 mm.

6. The method for preparing a composite organic hydrogen-barrier coating for stainless steel according to claim 4, characterized in that, When preparing the diluent, the stirring speed is 700 rpm and the stirring time is 20 minutes.

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