High-hydrogen embrittlement resistance austenitic corrosion-resistant steel, preparation method and related component

Abstract

The application discloses a kind of high hydrogen embrittlement-resistant austenitic corrosion-resistant steel, preparation method and related components.Corrosion-resistant steel component mass fraction is:C 0.06-0.08%, Si 0.40-0.60%, Mn 0.80-1.00%, Cr 16.00-17.00%, Ni 11.00-12.00%, Ti 0.20-0.40%, Sc 0.003-0.005%, Nb 0.10-0.30%, the rest Fe and impurities.Preparation method includes: vacuum induction melting, end stage adds Ni-Sc alloy and trace Mg denaturation;In turn forge, hot rolling, water cooling;1000-1200 ℃ solid solution 20-40 min after water cooling;5%-15% uniaxial tensile pre-strain.The application is synergized by Sc / Nb microalloying, Mg denaturation and pre-strain, forms multi-scale irreversible hydrogen trap, makes hydrogen-induced elongation loss rate reduce to 10.7% or less, hydrogen embrittlement resistance performance is increased by more than 50%, suitable for petrochemical hydrogenation and hydrogen energy storage and transport and other hydrogen-containing components.

Description

Technical Field

[0001] This invention belongs to the field of new materials technology, specifically relating to a high-resistance austenitic corrosion-resistant steel with high resistance to hydrogen embrittlement, its preparation method, and related components. Background Technology

[0002] In power transmission and transformation projects, a large number of steel structures (such as poles, supports, and fittings) are exposed to the atmosphere for extended periods, especially in coastal areas, areas with heavy acid rain, and industrial pollution zones. Traditional hot-dip galvanized carbon steel faces severe corrosion, high maintenance costs, and a significantly shortened galvanized layer lifespan, seriously threatening the safe operation of the power grid. Meanwhile, with the rapid development of the hydrogen energy industry, hydrogen storage and transportation, as well as petrochemical hydrogenation facilities, place increasingly stringent demands on the corrosion resistance and structural reliability of corrosion-resistant steel. Corrosion-resistant steel, with its excellent corrosion resistance, can achieve paint-free operation and long service life, making it an important alternative to traditional carbon steel.

[0003] Among various types of corrosion-resistant steel, austenitic corrosion-resistant steel is widely used in petrochemical hydrogenation units, hydrogenation reactor linings, high-temperature hydrogen pipelines, and hydrogen energy storage and transportation equipment due to its excellent high-temperature strength, creep resistance, and corrosion resistance. 321 corrosion-resistant steel is developed from 304 austenitic corrosion-resistant steel by adding titanium. Titanium preferentially combines with carbon to form TiC, effectively suppressing intergranular corrosion susceptibility and improving high-temperature structural stability. Furthermore, 321 corrosion-resistant steel has a face-centered cubic structure, high hydrogen solubility, and a low hydrogen diffusion coefficient. Its room-temperature plasticity and processing properties are also excellent, making it irreplaceable in the manufacture of equipment for hydrogen-contaminated environments.

[0004] However, despite the aforementioned advantages of austenitic corrosion-resistant steel, long-term research and engineering practice have revealed a significant risk of hydrogen embrittlement in hydrogen-containing environments. Premature failure of corrosion-resistant steel components in hydrogen-containing environments is frequent, becoming a key bottleneck restricting the safe operation of related equipment. Hydrogen embrittlement refers to the phenomenon where hydrogen atoms, after entering the metal interior, significantly reduce the plasticity and toughness of corrosion-resistant steel under stress, leading to sudden brittle fracture under loads below the conventional yield strength. Hydrogen segregation at defects such as dislocations, grain boundaries, and second-phase interfaces reduces atomic bonding forces, promoting crack nucleation and propagation. This type of brittle fracture is highly concealed and sudden, often without obvious signs of plastic deformation, making it extremely dangerous.

[0005] In practical engineering applications, corrosion-resistant steel components inevitably undergo processing such as pipe bending, container stamping, and welding. The residual deformation resulting from these processes significantly increases the dislocation density within the corrosion-resistant steel and may induce martensitic phase transformation, thereby altering the diffusion and accumulation patterns of hydrogen in the steel. Currently, existing research largely focuses on the hydrogen embrittlement mechanism of metastable corrosion-resistant steels, while systematic studies on stabilized 321 corrosion-resistant steel in hydrogen-containing environments are scarce. In particular, the quantitative relationship between pre-strain introduced by processing deformation, microstructure evolution, and hydrogen embrittlement susceptibility remains unclear. Those skilled in the art lack a clear understanding and experimental evidence regarding whether pre-strain worsens or improves the hydrogen embrittlement resistance of 321 corrosion-resistant steel, and even more so, lacks an effective means of actively controlling hydrogen embrittlement susceptibility based on pre-strain parameters. This results in the inability to effectively avoid hydrogen embrittlement risks in the design and fabrication of hydrogen-exposed components. Summary of the Invention

[0006] The purpose of this invention is to address the problem that existing austenitic corrosion-resistant steels are highly susceptible to hydrogen embrittlement in hydrogen-containing environments, and that there is a lack of methods for regulating hydrogen embrittlement resistance based on pre-strain variables.

[0007] The objective of this invention is achieved through the following technical solution: A high-resistance austenitic corrosion-resistant steel with hydrogen embrittlement, comprising, by mass fraction: C 0.06%~0.08%, Si 0.40%~0.60%, Mn 0.80%~1.00%, Cr 16.00%~17.00%, Ni 11.00%~12.00%, Ti 0.20%~0.40%, Sc 0.003%~0.005%, Nb 0.10%~0.30%, with the balance being iron and unavoidable impurities; The corrosion-resistant steel is microalloyed with Sc and Nb to form multi-scale irreversible hydrogen traps at the steel interface.

[0008] Preferably, the hydrogen-induced elongation reduction rate of the corrosion-resistant steel is ≤10.7%.

[0009] Preferably, Sc and Nb in the corrosion-resistant steel exist in the form of Sc-Nb composite precipitates, and Sc-OS inclusions serve as heterogeneous nucleation cores for Nb(C,N) to form the Sc-Nb composite precipitates.

[0010] Preferably, the corrosion-resistant steel must have a dislocation density ≥ 3.69 × 10⁻⁶. 14 m 2 .

[0011] Based on the same inventive concept, the present invention also provides a method for preparing a highly hydrogen-embrittled austenitic corrosion-resistant steel, characterized in that the method includes the following steps: According to the chemical composition ratio of the high hydrogen embrittlement resistant austenitic corrosion-resistant steel, each raw material component is taken, and after melting, forging, hot rolling and water cooling, hot-rolled plate is obtained; The hot-rolled sheet is solution treated and then water-cooled; The solution-treated plate was subjected to uniaxial tensile pre-strain treatment to obtain the high hydrogen embrittlement resistant austenitic corrosion-resistant steel.

[0012] Preferably, after melting, bottom-pouring casting is used and argon gas is applied above the ingot mold for protection. The casting temperature is 1480~1520℃, and air cooling is used after casting at a rate of 10~15℃ / s.

[0013] Preferably, the melting is performed using vacuum induction melting.

[0014] Preferably, the vacuum degree of the vacuum induction melting is ≤5Pa, and the melting temperature is 1550℃~1580℃.

[0015] Preferably, a Ni-Sc master alloy is added at the end of the vacuum induction melting process, and 0.001%~0.005% Mg by mass is added for inclusion modification treatment.

[0016] Preferably, the mass fraction of Sc in the Ni-Sc master alloy is 15%~20%.

[0017] Preferably, the charging sequence of the smelting is as follows: first, Fe, Cr, Ni, Mn and Si base materials are added; after the base materials are completely melted, Fe-Nb master alloy and Fe-Ti master alloy are added in sequence and kept at a constant temperature; finally, Ni-Sc master alloy is added 5 to 8 minutes before tapping.

[0018] Preferably, after the inclusion modification treatment, the size of the composite inclusions formed in the corrosion-resistant steel is <2μm.

[0019] Preferably, the forging process conditions include: a forging temperature range of 1100℃~1200℃, a billet heating temperature of 1200℃~1250℃ before forging, and a holding time of 2h~4h.

[0020] Preferably, the hot rolling start temperature is 1100℃~1200℃, the final rolling temperature is 900℃~1050℃, and the total hot rolling reduction is 70%~90%.

[0021] Preferably, the thickness of the sheet after hot rolling is 12mm~15mm.

[0022] Preferably, the solution treatment temperature is 1000℃~1200℃, and the holding time is 20min~40min.

[0023] Preferably, the cooling rate after solution treatment is greater than 70°C / s.

[0024] Preferably, the prestress of the uniaxial tensile prestress treatment is 5% to 15%.

[0025] Based on the same inventive concept, the present invention also provides a hydrogen-resistant component, which is made of the high hydrogen embrittlement resistant austenitic corrosion-resistant steel described above, and is used in petrochemical hydrogenation or hydrogen energy storage and transportation operations.

[0026] Preferably, the hydrogen-containing component is a high-temperature hydrogen transport pipeline, a hydrogenation reactor lining, or a structural component of a hydrogenation device.

[0027] Based on the same inventive concept, the present invention also provides a power transmission and transformation steel component, which is made of the high hydrogen embrittlement resistant austenitic corrosion-resistant steel described above, and the power transmission and transformation steel component is a pole, support structure or power fitting for power transmission and transformation projects.

[0028] This invention achieves synergistic optimization of the microstructure of austenitic corrosion-resistant steel by combining the rare earth element Sc and the strong carbide-forming element Nb, thereby significantly improving its resistance to hydrogen embrittlement. Specifically, Sc, as a rare earth element, is introduced into the 321 austenitic corrosion-resistant steel system for the first time. Sc has a large atomic radius (approximately 1.64 Å), much larger than Fe (1.24 Å). When dissolved in the austenitic matrix, Sc generates a strong elastic distortion field, promoting the formation of high-density dislocations and ensuring their uniform distribution. More importantly, Sc has extremely high affinity for oxygen and sulfur, preferentially reacting with O and S in molten steel to form nano- to submicron-sized composite inclusions. These inclusions are small in size (typically ≤200 nm), spherical or near-spherical, and uniformly distributed. They are coherent or semi-coherent with the steel matrix interface and can act as irreversible hydrogen traps, permanently capturing diffusing hydrogen atoms and preventing their migration to the crack tip. Compared to traditional rare earth elements such as Y, Ce, and La, Sc has a lower free energy for the formation of oxysulfides, resulting in higher thermal stability of its inclusions and making them less prone to aggregation and growth during subsequent solution treatment (1000-1200℃). Furthermore, the addition of Sc promotes the uniform precipitation of Nb: Sc-OS inclusions act as heterogeneous nucleation sites for Nb(C,N), transforming coarse, strip-like niobium carbonitride into dispersed, fine spherical inclusions, reducing stress concentration sources, and increasing the number of phase interfaces to form Sc-OS / Nb(C,N) composite hydrogen traps. This synergistic effect of the composite traps pins hydrogen atoms in multiple layers, significantly reducing the effective diffusion coefficient of hydrogen.

[0029] Nitrogen (Nb), as a strong carbide-forming element, preferentially combines with C and N in steel to form micron- to submicron-sized niobium carbonitride precipitates. These precipitates not only enhance the mechanical properties of the material, but more importantly, their interfaces with the matrix can form stable, irreversible hydrogen traps, further inhibiting hydrogen migration. The combined addition of Sc and Nb produces a synergistic effect: Sc optimizes the distribution and morphology of the Nb precipitates, reducing stress concentration sources; while Nb reduces the formation of harmful carbides by consuming free C and N. Together, they significantly reduce the hydrogen embrittlement sensitivity coefficient of the material.

[0030] Furthermore, the solution heat treatment process plays a crucial role in controlling hydrogen embrittlement. The preferred solution temperature in this invention is 1100-1200℃, the holding time is 30 min, and the cooling rate is greater than 70°C / s. Within this temperature range, alloying elements (such as Cr, Ni, Ti, Nb, etc.) can fully dissolve in the austenitic matrix, forming a homogeneous solid solution and avoiding element segregation and the precipitation of harmful phases. Appropriate holding time ensures both compositional homogenization and prevents excessive grain growth. Most importantly, rapid cooling yields a uniform austenitic structure and suppresses the precipitation of brittle phases such as carbides during cooling, thereby improving the room temperature stability of austenite. A stable austenitic matrix is ​​less prone to strain-induced martensitic transformation during service, thus reducing the risk of interfaces acting as hydrogen enrichment and crack nucleation sites.

[0031] Specifically, Sc and Nb are both large atomic radius elements. When they dissolve in an austenitic matrix or form fine precipitates, they induce significant elastic distortion fields in the surrounding lattice. This distortion field promotes the generation and uniform distribution of high-density dislocations and also makes dislocation lines and their surrounding strain fields preferred sites for hydrogen atoms. Compared with interface-type irreversible hydrogen traps, dislocation hydrogen traps have moderate trapping energy, which can reversibly trap and release hydrogen atoms within a certain temperature range, thereby effectively delaying hydrogen diffusion and migration. More importantly, the uniformly distributed dislocation network can "pin" hydrogen atoms inside the matrix, preventing them from accumulating in local areas and inducing hydrogen-induced cracks. At the same time, the combined addition of Sc and Nb further modulates the dislocation slip mode and dislocation cell structure by refining the grains and increasing the proportion of twin boundaries, forming a multi-scale hydrogen trap network from lattice distortion, dislocation lines to grain boundaries, synergistically improving the hydrogen embrittlement resistance of austenitic corrosion-resistant steel.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes composite addition of Sc and Nb elements combined with Ti microalloying to form multi-scale irreversible hydrogen traps at the steel interface, significantly reducing the hydrogen embrittlement sensitivity of corrosion-resistant steel. In principle, Sc, as a rare earth element, possesses a large atomic radius and extremely strong affinity for oxygen and sulfur. When Sc dissolves in an austenitic matrix, it generates a strong elastic distortion field, promoting the formation of high-density dislocations and ensuring their uniform distribution. Simultaneously, it preferentially reacts with O and S to form nano- to submicron-sized, uniformly distributed spherical Sc-OS composite inclusions. These inclusions are coherent or semi-coherent with the matrix interface and can permanently trap diffused hydrogen atoms as irreversible hydrogen traps. More importantly, the Sc-OS inclusions can act as heterogeneous nucleation sites for Nb(C,N), transforming coarse strips of niobium carbonitride into dispersed fine spheres, reducing stress concentration sources, and forming Sc-OS / Nb(C,N) composite hydrogen traps. As a strong carbide-forming element, Nb consumes free C and N to reduce harmful carbides, and its precipitation phase interface can also form stable traps. The synergy of these two factors causes hydrogen atoms to be pinned in multiple layers, significantly reducing the effective diffusion coefficient of hydrogen and achieving a leap in resistance to hydrogen embrittlement.

[0033] This invention innovatively employs a final stage of the smelting process, adding a Ni-Sc master alloy and a trace amount of Mg to modify inclusions. This optimizes the microstructure and improves rare earth recovery from the source. Since Sc is easily oxidized and burned off, adding the Ni-Sc master alloy at the final stage before tapping encapsulates the Sc with Ni, and the alloy density is similar to that of the molten steel, significantly reducing the Sc burn-off rate and increasing the recovery rate from the conventional 30-40% to over 70%, thus avoiding the waste of expensive rare earth elements. The addition of trace amounts of Mg modifies inclusions such as Sc2O3 and Sc2S3, which might otherwise aggregate and grow, transforming them into fine (<2μm), dispersed composite inclusions. These dispersed inclusions act as additional irreversible hydrogen traps, increasing the hydrogen trap density, and effectively prevent the aggregation of large inclusions, eliminating the risk of them becoming nucleation sources for hydrogen-induced cracks. By combining vacuum induction melting to remove harmful gases such as hydrogen, oxygen, and nitrogen from the source, this process lays a pure and optimized microstructure foundation for the high hydrogen embrittlement resistance of corrosion-resistant steel in the early stages of preparation.

[0034] This invention constructs a multi-scale, hierarchical hydrogen trap adsorption network, from lattice distortion and dislocation lines to grain boundaries, through a combination of solution treatment and uniaxial tensile pre-strain treatment with specific parameters. After solution treatment at 1000-1200℃ and rapid cooling, the corrosion-resistant steel obtains a uniform single-phase austenitic structure, suppressing the precipitation of brittle phases, improving the room temperature stability of the matrix, and avoiding the risk of hydrogen enrichment caused by strain-induced martensitic phase transformation during service. Based on this, a pre-strain of 5%-15% is applied to introduce a suitable geometrically necessary dislocation density, forming dislocation hydrogen traps. These dislocation traps possess moderate trapping energy, capable of reversibly capturing and releasing hydrogen within a certain range, effectively delaying hydrogen diffusion and migration, and "pinning" hydrogen atoms inside the matrix to prevent local enrichment and crack induction. Simultaneously, the dislocation network introduced by the pre-strain, together with the lattice distortion field generated by Sc / Nb and the precipitated phase interface traps, forms a hierarchical synergy, constituting a multi-scale hydrogen trap network. If the pre-strain is too large (e.g., 30%), it will lead to premature failure due to work hardening; while a precise pre-strain of 5%-15% reduces the hydrogen-induced elongation loss rate from 22.3% to below 10.7%, improving the hydrogen embrittlement resistance by more than 50%, and achieving precise control of the hydrogen embrittlement sensitivity by the pre-strain. Attached Figure Description

[0035] Figure 1 Grain boundary feature distribution diagram of untreated 321 austenitic corrosion-resistant steel; Figure 2 The geometrically required dislocation density distribution diagram for untreated 321 austenitic corrosion-resistant steel; Figure 3 This is a grain boundary feature distribution diagram of the treated 321 austenitic corrosion-resistant steel. Figure 4 This is a geometrical dislocation density distribution diagram of the treated 321 austenitic corrosion-resistant steel. Detailed Implementation

[0036] The technical solution will be further described below with reference to the accompanying drawings and specific embodiments to help understand the content of the present invention.

[0037] Example 1 This invention provides a high-resistance austenitic corrosion-resistant steel with hydrogen embrittlement, comprising the following components by mass percentage: C: 0.06-0.08%, Si: 0.40-0.60%, Mn: 0.80-1.00%, Cr: 16.00-17.00%, Ni: 11.00-12.00%, Ti: 0.20-0.40%, Sc: 0.003-0.005%, Nb: 0.10-0.30%, and the balance being Fe and unavoidable impurities; wherein, the hydrogen embrittlement-resistant austenitic corrosion-resistant steel is formed by adding Sc and Nb composite microalloying to create irreversible hydrogen traps at the internal interface of the hydrogen embrittlement-resistant austenitic corrosion-resistant steel.

[0038] Corrosion-resistant steel is prepared through smelting, forging, and hot rolling. Subsequently, it undergoes solution treatment to homogenize its microstructure. Finally, a CMT5205 microcomputer-controlled electronic universal testing machine is used for tensile pre-strain treatment to apply a certain amount of deformation. The specific steps include: Step (1) The corrosion-resistant steel is smelted by precise proportioning and batching, using a specific feeding method and sequence, and then bottom-cast. The forging temperature range is T. 锻造 After forging, the billet is heated to T. 加热 And keep warm 保温 time; Step (2) then in T 开轧 The initial rolling and final rolling temperatures are controlled at T. 终轧 The total reduction is Δh, and the final plate thickness is approximately d. 板厚 After rolling, it is immediately placed in a liquid cooling medium for rapid cooling to room temperature; Step (3) Place the corrosion-resistant steel plate in a box-type resistance furnace and heat it to T. 固溶 Post-insulation t 固溶 The solution is then applied to dissolve the carbides formed during hot rolling, and then immediately placed in a liquid cooling medium for rapid cooling to room temperature. Step (4) Cut the plate material that has undergone the above treatment into a plate tensile specimen conforming to the national standard GB / T228.1-2021 Metallic corrosion-resistant steel - Tensile testing - Part 1: Room temperature test method; Step (5) The standard-sized tensile specimen is stretched using a CMT5205 microcomputer-controlled electronic universal testing machine until the extensometer displacement ΔL is interrupted, and the initial strain rate is ε. Furthermore, in step (1), the melting method adopts vacuum induction melting (VIM) + argon-protected remelting. The vacuum degree is controlled at ≤5Pa, and the melting temperature is 1550-1600℃. Vacuum melting can effectively remove harmful gases such as hydrogen, oxygen, and nitrogen from the molten steel, avoid the formation of large-sized rare earth oxide inclusions, and reduce the source of diffusible hydrogen from the source; Furthermore, in step (1), the base materials (Fe, Cr, Ni, Mn, Si) are first added. After complete melting, Nb (in the form of Fe-Nb master alloy) and Ti (in the form of Fe-Ti) are added sequentially. The mixture is kept at a temperature of 10-15 min to allow Nb and Ti to fully dissolve and form fine carbonitrides. Ni-Sc master alloy is added at the end of the smelting process (5-8 min before tapping). The density of Ni-Sc master alloy is similar to that of molten steel, and Sc is coated with Ni, which can significantly reduce the burn-off rate of Sc and increase the yield (from the conventional 30-40% to over 70%). At the same time, electromagnetic stirring is performed for 2-3 min after addition to ensure uniform distribution of Sc. Furthermore, in step (1), after the addition of Sc, trace amounts of Mg (0.001-0.005 wt%) or Ca (0.001-0.003 wt%) are added to the molten steel to modify the rare earth oxide sulfides, transforming the potentially aggregated Sc2O3, Sc2S3, and other inclusions into fine, dispersed composite inclusions (size <2 μm). These dispersed inclusions can act as additional irreversible hydrogen traps, while avoiding hydrogen-induced crack nucleation caused by large inclusions. Furthermore, in step (1), bottom-pouring casting is adopted, and argon gas is applied above the ingot mold to prevent secondary oxidation of the molten steel. The casting temperature is controlled at 1480-1520℃, and after casting, air cooling (10~15℃ / s) is used instead of traditional air cooling to refine the ingot structure, reduce dendrite segregation, and provide a more uniform initial structure for subsequent hot rolling; Furthermore, in step (1), the forging and rolling temperature range T of the corrosion-resistant steel is... 锻造 The billet heating temperature is 1100-1200℃, and the billet heating temperature T is... 加热 The temperature is 1200-1250℃, and the holding time is t. 保温 The value can be 2-4h; Furthermore, in step (2), the hot rolling start temperature T 开轧 The temperature should be controlled at 1100-1200℃, with a final rolling temperature T. 终轧 The temperature is controlled at 900-1050℃, the total reduction Δh is 70-90%, and the final plate thickness d 板厚 Approximately 12-15mm thick, the liquid cooling medium is deionized water to achieve a faster cooling rate, thereby obtaining a single-phase austenitic structure; Furthermore, in step (3), the T in the solution treatment of corrosion-resistant steel plate 固溶 Temperature range: 1000-1200℃, solution treatment holding time: t 固溶 The value range is 20-40 min, and the liquid cooling medium is deionized water; Furthermore, in step (4), the gauge length of the tensile specimen is 50 mm, the length of the parallel end is 60 mm, the total length is 120 mm, the width is 30 mm, and the thickness is 3.5 mm. Furthermore, in step (5), the pre-strain variable ΔL is 5%-20%, and the initial strain rate ε is 4*10-5s-1.

[0039] The specific implementation process of this embodiment is as follows: The raw materials are weighed by mass fraction as follows: C 0.073%, Si 0.53%, Mn 0.93%, Cr 16.70%, Ni 11.70%, Ti 0.33%, Sc 0.0043%, Nb 0.23%, with the balance being Fe and unavoidable impurities.

[0040] Preparation method: Vacuum induction melting was used, with the vacuum degree controlled at 2 Pa and the melting temperature at 1572℃. At the end of the melting process, a Ni-Sc master alloy with a Sc mass fraction of 18.5% was added, and 0.0038% Mg was added for inclusion modification treatment. The feeding sequence was the same as in Example 1, with Ni-Sc added 7 minutes before tapping. Bottom-pouring casting temperature was 1508℃, and the air cooling rate was 13.5℃ / s. Forging temperature range was 1170℃, billet heating temperature was 1238℃, and holding time was 3.5h. Hot rolling initial rolling temperature was 1175℃, final rolling temperature was 1010℃, total reduction was 85%, plate thickness was 13mm, and water cooling was used. Solution treatment temperature was 1140℃, holding time was 35min, and water cooling was used. Uniaxial tensile pre-strain was 12%.

[0041] In this embodiment of the invention, the hydrogen-induced elongation loss rate (%) is used to represent the hydrogen embrittlement resistance of the material, and the smaller the value, the better the hydrogen embrittlement resistance.

[0042]

[0043] In the formula EL loss Indicating hydrogen embrittlement sensitivity, EL unchargewei EL represents the engineering strain at fracture of a hydrogen-free specimen. charge The strain is the engineering strain at which the hydrogen-loaded sample fractures.

[0044] The samples were placed in a box-type resistance furnace at 1000-1150℃ and held for 30 minutes, followed by water cooling to obtain solution-treated materials. Tensile testing was then performed using a CMT5205 microcomputer-controlled electronic universal testing machine, interrupting the tensile test until 5%-15% of the extensometer displacement was achieved. The treated samples were prepared into standard tensile specimens, and then subjected to slow stress tensile testing at room temperature using an NFKK-50 stress corrosion testing machine at a strain rate of 5*10⁻⁵ / s on both hydrogen-free and hydrogen-charged specimens. One set of pre-strained specimens was hydrogen-charged in a mixed solution of 0.01 mol / L sulfuric acid, 3 g / L ammonium hydrosulfide, and 1 g / L thiourea, with the electrolytic hydrogen charging current density controlled at 6 A / m. 2 The entire electrochemical hydrogen charging process was conducted at room temperature. During hydrogen charging, the platinum sheet served as the anode and the sample as the cathode. Hydrogen atoms were generated on the sample surface and diffused into the material via the electrochemical reaction during electrolysis, causing hydrogen embrittlement. A second group of pre-strained samples, without hydrogen charging, were also stretched to fracture as a reference. Experimental data are shown in Tables 1 and 2 below.

[0045] Table 1 Test results of samples at different solution temperatures

[0046] Table 2 Test results of specimens with different pre-strain deformation amounts

[0047] The smelting process of this invention results in a total oxygen content of ≤0.0015% and a hydrogen content of ≤0.0002% in the steel, which significantly reduces the internal hydrogen source that can promote hydrogen embrittlement and reduces the hydrogen embrittlement sensitivity of 321 corrosion-resistant steel. The corrosion-resistant steel treated with pre-strain treatment has better hydrogen embrittlement resistance than corrosion-resistant steel treated with traditional methods to prevent hydrogen embrittlement. The Sc recovery rate in the corrosion-resistant steel of this invention is ≥70%, which avoids the waste of rare earth elements. Moreover, the Sc-OS inclusions are dispersed in a submicron scale, forming a multi-scale adsorption network with the dislocation hydrogen traps introduced by subsequent pre-strain, which further reduces the hydrogen-induced elongation loss rate.

[0048] Compared with existing complex processes such as alloy composition control and surface laser shock, the preparation process provided by this invention only requires conventional pre-deformation processing equipment, without the need for additional complex surface treatment processes, and can be directly applied to pre-formed 321 corrosion-resistant steel products.

[0049] Example 2 Based on the same inventive concept, the present invention also provides a method for preparing a highly hydrogen-embrittled austenitic corrosion-resistant steel, characterized in that the method includes the following steps: According to the chemical composition ratio of the high hydrogen embrittlement resistant austenitic corrosion-resistant steel, each raw material component is taken, and after melting, forging, hot rolling and water cooling, hot-rolled plate is obtained; The hot-rolled sheet is solution treated and then water-cooled; The solution-treated plate was subjected to uniaxial tensile pre-strain treatment to obtain the high hydrogen embrittlement resistant austenitic corrosion-resistant steel.

[0050] Preferably, after melting, bottom-pouring casting is used and argon gas is applied above the ingot mold for protection. The casting temperature is 1480~1520℃, and air cooling is used after casting at a rate of 10~15℃ / s.

[0051] Preferably, the melting is performed using vacuum induction melting.

[0052] Preferably, the vacuum degree of the vacuum induction melting is ≤5Pa, and the melting temperature is 1550℃~1580℃.

[0053] Preferably, a Ni-Sc master alloy is added at the end of the vacuum induction melting process, and 0.001%~0.005% Mg by mass is added for inclusion modification treatment.

[0054] Preferably, the mass fraction of Sc in the Ni-Sc master alloy is 15%~20%.

[0055] Preferably, the charging sequence of the smelting is as follows: first, Fe, Cr, Ni, Mn and Si base materials are added; after the base materials are completely melted, Fe-Nb master alloy and Fe-Ti master alloy are added in sequence and kept at a constant temperature; finally, Ni-Sc master alloy is added 5 to 8 minutes before tapping.

[0056] Preferably, after the inclusion modification treatment, the size of the composite inclusions formed in the corrosion-resistant steel is <2μm.

[0057] Preferably, the forging process conditions include: a forging temperature range of 1100℃~1200℃, a billet heating temperature of 1200℃~1250℃ before forging, and a holding time of 2h~4h.

[0058] Preferably, the hot rolling start temperature is 1100℃~1200℃, the final rolling temperature is 900℃~1050℃, and the total hot rolling reduction is 70%~90%.

[0059] Preferably, the thickness of the sheet after hot rolling is 12mm to 15mm.

[0060] Preferably, the solution treatment temperature is 1000℃~1200℃, and the holding time is 20min~40min.

[0061] Preferably, the cooling rate after solution treatment is greater than 70°C / s.

[0062] Preferably, the prestress of the uniaxial tensile prestress treatment is 5% to 15%.

[0063] The specific implementation process of this embodiment is as follows: The raw materials are weighed by mass fraction as follows: C 0.065%, Si 0.45%, Mn 0.85%, Cr 16.25%, Ni 11.25%, Ti 0.25%, Sc 0.0035%, Nb 0.15%, with the balance being Fe and unavoidable impurities.

[0064] Preparation method: Vacuum induction melting was used, with the vacuum degree controlled at 4 Pa ​​and the melting temperature at 1558℃. At the end of the melting process, a Ni-Sc master alloy with a Sc mass fraction of 16% was added, and 0.002% Mg was added for inclusion modification treatment. The feeding sequence was the same as in Example 1, with Ni-Sc added 6 minutes before tapping. Bottom-pouring casting temperature was 1490℃, and the air cooling rate was 11.5℃ / s. The forging temperature range was 1125℃, the billet heating temperature was 1215℃, and the holding time was 2.5 hours. The hot rolling initial rolling temperature was 1130℃, the final rolling temperature was 930℃, the total reduction was 75%, the plate thickness was 14 mm, and water cooling was used. The solution treatment temperature was 1050℃, the holding time was 25 minutes, and water cooling was used. The uniaxial tensile pre-strain was 8%.

[0065] This invention utilizes the composite addition of Sc and Nb, combined with Ti composite microalloying, to form multi-scale irreversible hydrogen traps at the steel interface. The preparation method includes: vacuum induction melting (vacuum degree ≤5Pa, 1550-1580℃), sequentially adding Fe, Cr, Ni, Mn, Si, Fe-Nb, and Fe-Ti, with a final addition of a Ni-Sc master alloy and 0.001-0.005wt% Mg for inclusion modification treatment, followed by bottom casting and air cooling; then forging, hot rolling, and water cooling; followed by solution treatment at 1000-1200℃ for 20-40 min and water cooling; finally, uniaxial tensile pre-strain treatment with a pre-strain of 5%-15%. This invention, through the synergistic effect of Sc / Nb microalloying, Mg dispersion modification, and pre-strain, forms multi-scale irreversible hydrogen traps, reducing the hydrogen-induced elongation loss from 22.3% to below 10.7%, and improving hydrogen embrittlement resistance by over 50%. This method can be directly applied to the molding of 321 corrosion-resistant steel products and is suitable for hydrogen-contaminated environments such as petrochemical hydrogenation and hydrogen energy storage and transportation.

[0066] Example 3 A method for preparing a high-resistance austenitic corrosion-resistant steel for hydrogen embrittlement, wherein the raw materials are weighed by mass fraction as follows: C 0.07%, Si 0.50%, Mn 0.90%, Cr 16.50%, Ni 11.50%, Ti 0.30%, Sc 0.004%, Nb 0.20%, with the balance being Fe and unavoidable impurities.

[0067] Preparation method: Vacuum induction melting was used, with the vacuum degree controlled at 3 Pa and the melting temperature at 1565℃. At the end of the melting process, a Ni-Sc master alloy with a Sc mass fraction of 17.5% was added, and 0.003% Mg was added for inclusion modification treatment. The feeding sequence was the same as in Example 1, with Ni-Sc added 6.5 min before tapping. Bottom-pouring casting temperature was 1500℃, and the air cooling rate was 12.5℃ / s. Forging temperature range was 1150℃, billet heating temperature was 1225℃, and holding time was 3 h. Hot rolling initial rolling temperature was 1150℃, final rolling temperature was 975℃, total reduction was 80%, plate thickness was 13.5 mm, and water cooling was used. Solution treatment temperature was 1100℃, holding time was 30 min, and water cooling was used. Uniaxial tensile pre-strain was 10%.

[0068] Example 4 A method for preparing a high-resistance austenitic corrosion-resistant steel for hydrogen embrittlement, wherein the raw materials are weighed by mass fraction as follows: C 0.06%, Si 0.40%, Mn 0.80%, Cr 16.00%, Ni 11.00%, Ti 0.20%, Sc 0.003%, Nb 0.10%, with the balance being Fe and unavoidable impurities.

[0069] Preparation process: Vacuum induction melting was employed, with the vacuum level controlled at 5 Pa and the melting temperature at 1550℃. Towards the end of melting, a Ni-Sc master alloy with a Sc mass fraction of 15% was added, along with 0.001% Mg for inclusion modification. The feeding sequence was as follows: first, the base material was added; after complete melting, Fe-Nb and Fe-Ti were added sequentially; the Ni-Sc master alloy was added 5 minutes before tapping. After melting, bottom-pouring casting was used at a casting temperature of 1480℃, with argon gas protection applied above the ingot mold. After casting, air cooling was employed at a rate of 10℃ / s. Forging was then carried out at a temperature range of 1100℃, with the billet heating temperature at 1200℃ and a holding time of 2 hours. Hot rolling began at 1100℃, ended at 900℃, with a total reduction of 70%, resulting in a final plate thickness of 15mm, followed by water cooling. The hot-rolled plate was solution treated at 1000℃ for 20 minutes, followed by water cooling (cooling rate >70℃ / s). Finally, uniaxial tensile pre-strain treatment was performed with a pre-strain of 5%.

[0070] Example 5 A method for preparing a high-resistance austenitic corrosion-resistant steel for hydrogen embrittlement, wherein the raw materials are weighed by mass fraction as follows: C 0.078%, Si 0.58%, Mn 0.97%, Cr 16.90%, Ni 11.90%, Ti 0.38%, Sc 0.0048%, Nb 0.28%, with the balance being Fe and unavoidable impurities.

[0071] Preparation method: Vacuum induction melting was used, with the vacuum degree controlled at 1 Pa and the melting temperature at 1578℃. At the end of the melting process, a Ni-Sc master alloy with a Sc mass fraction of 19% was added, and 0.0048% Mg was added for inclusion modification treatment. The charging sequence was the same as in Example 1, with Ni-Sc added 7.5 min before tapping. Bottom-pouring casting temperature was 1515℃, and the air cooling rate was 14.5℃ / s. The forging temperature range was 1190℃, the billet heating temperature was 1245℃, and the holding time was 3.8 h. The hot rolling initial rolling temperature was 1190℃, the final rolling temperature was 1040℃, the total reduction was 88%, the plate thickness was 12.3 mm, and water cooling was used. The solution treatment temperature was 1180℃, the holding time was 38 min, and water cooling was used. The uniaxial tensile pre-strain was 14%.

[0072] Example 6 A method for preparing a high-resistance austenitic corrosion-resistant steel for hydrogen embrittlement, wherein the raw materials are weighed by mass fraction as follows: C 0.08%, Si 0.60%, Mn 1.00%, Cr 17.00%, Ni 12.00%, Ti 0.40%, Sc 0.005%, Nb 0.30%, with the balance being Fe and unavoidable impurities.

[0073] Preparation method: Vacuum induction melting was used, with the vacuum degree controlled at 1 Pa and the melting temperature at 1580℃. At the end of the melting process, a Ni-Sc master alloy with a Sc mass fraction of 20% was added, and 0.005% Mg was added for inclusion modification treatment. The feeding sequence was the same as in Example 1, with Ni-Sc added 8 minutes before tapping. Bottom-pouring casting temperature was 1520℃, and the air cooling rate was 15℃ / s. The forging temperature range was 1200℃, the billet heating temperature was 1250℃, and the holding time was 4 hours. The hot rolling initial rolling temperature was 1200℃, the final rolling temperature was 1050℃, the total reduction was 90%, the plate thickness was 12mm, and water cooling was used. The solution treatment temperature was 1200℃, the holding time was 40 minutes, and water cooling was used. The uniaxial tensile pre-strain was 15%.

[0074] Example 7 A method for preparing a high-resistance austenitic corrosion-resistant steel with hydrogen embrittlement, wherein the raw materials are weighed by mass fraction as follows: C 0.07%, Si 0.50%, Mn 0.90%, Cr 16.50%, Ni 11.50%, Ti 0.30%, Sc 0.005% (Sc is taken as the upper limit), Nb 0.30% (Nb is taken as the upper limit), with the balance being Fe and unavoidable impurities.

[0075] Preparation method: Vacuum induction melting was used, with the vacuum degree controlled at 2 Pa and the melting temperature at 1570℃. At the end of the melting process, a Ni-Sc master alloy with a Sc mass fraction of 18% was added, and 0.004% Mg was added for inclusion modification treatment. The feeding sequence was the same as in Example 1, with Ni-Sc added 7 minutes before tapping. Bottom-pouring casting temperature was 1500℃, and the air cooling rate was 13℃ / s. The forging temperature range was 1150℃, the billet heating temperature was 1230℃, and the holding time was 3 hours. The hot rolling initial rolling temperature was 1150℃, the final rolling temperature was 980℃, the total reduction was 85%, the plate thickness was 12.5 mm, and water cooling was used. The solution treatment temperature was 1100℃, the holding time was 30 minutes, and water cooling was used. The uniaxial tensile pre-strain was 10%.

[0076] Comparative Example 1 To compare the differences in microstructure and properties between the treated material and the original material, the original material was solution-treated at 1050℃ for 30 min, followed by a slow-stress tensile test at room temperature. The test results are shown in Table 2. It can be observed that, under the same solution treatment conditions, the hydrogen embrittlement resistance of the specimen with a certain pre-strain is improved compared to that of the raw material. Simultaneously, specimens treated at 1050℃ were subjected to room-temperature uniaxial tensile pre-deformation with a deformation of 30%. The hydrogen charging and tensile test conditions were the same as in the previous example. The results showed that the material exhibited significant work hardening leading to premature failure.

[0077] The material treated according to this invention was made into a standard metallographic sample. After grinding, mechanical polishing, and electrolytic polishing, the grain size, special grain boundary ratio, and geometrically essential dislocation density of the material were tested using backscattered electron diffraction technology. The geometrically essential dislocation density in the microstructure reached 3.69*10 14 m -2 Under the same solid solution conditions, the hydrogen-induced elongation loss rate decreased significantly relative to the parent material, and the material's resistance to hydrogen embrittlement was improved to a certain extent.

[0078] Figure 1 This shows the distribution of grain boundary characteristics in the raw materials, where the proportion of Σ special grain boundaries is 53%. Figure 2 The geometrically necessary dislocation density distribution in the raw material is 0.96*10. 14 m -2 ; Figure 3 The figure shows the distribution of grain boundary features in the microstructure of the material treated by the above method, where the proportion of Σ special grain boundaries is 31%. Figure 4 The figure shows the geometrically required dislocation density distribution in the microstructure of the material treated by the above method, reaching 3.69*10. 14 m -2 .

[0079] Example 8 Based on the same inventive concept, the present invention also provides a hydrogen-resistant component, which is made of the high hydrogen embrittlement resistant austenitic corrosion-resistant steel described above, and is used in petrochemical hydrogenation or hydrogen energy storage and transportation operations.

[0080] Preferably, the hydrogen-containment component is a high-temperature hydrogen transport pipeline, a hydrogenation reactor lining, or a structural component of a hydrogenation device.

[0081] Example 9 Based on the same inventive concept, the present invention also provides a power transmission and transformation steel component, which is made of the high hydrogen embrittlement resistant austenitic corrosion-resistant steel described above, and the power transmission and transformation steel component is a pole, support structure or power fitting for power transmission and transformation projects.

[0082] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention.

Claims

1. A highly resistant austenitic corrosion-resistant steel with high resistance to hydrogen embrittlement, characterized in that, Its chemical composition by mass fraction includes: C 0.06%~0.08%, Si 0.40%~0.60%, Mn 0.80%~1.00%, Cr 16.00%~17.00%, Ni 11.00%~12.00%, Ti 0.20%~0.40%, Sc 0.003%~0.005%, Nb 0.10%~0.30%, with the balance being iron and unavoidable impurities; The corrosion-resistant steel is microalloyed with Sc and Nb to form multi-scale irreversible hydrogen traps at the steel interface.

2. The high-resistance austenitic corrosion-resistant steel according to claim 1, characterized in that, The hydrogen-induced elongation reduction rate of the corrosion-resistant steel is ≤10.7%.

3. The high-resistance austenitic corrosion-resistant steel according to claim 1, characterized in that, In the corrosion-resistant steel, Sc and Nb exist in the form of Sc-Nb composite precipitates, and Sc-OS inclusions serve as heterogeneous nucleation sites for Nb(C,N) to form the Sc-Nb composite precipitates.

4. The high-resistance austenitic corrosion-resistant steel according to claim 1, characterized in that, The geometric requirement for the corrosion-resistant steel is a dislocation density ≥ 3.69 × 10⁻⁶. 14 m 2 .

5. A method for preparing a highly resistant austenitic corrosion-resistant steel with high resistance to hydrogen embrittlement, characterized in that, The method includes the following steps: According to the chemical composition ratio of the high hydrogen embrittlement resistant austenitic corrosion-resistant steel as described in any one of claims 1 to 4, each raw material component is taken, and after melting, forging, hot rolling and water cooling, hot-rolled plate is obtained; The hot-rolled sheet is solution treated and then water-cooled; The solution-treated plate is subjected to uniaxial tensile pre-strain treatment to obtain the high hydrogen embrittlement resistant austenitic corrosion-resistant steel as described in any one of claims 1 to 4.

6. The method for preparing high-resistance austenitic corrosion-resistant steel according to claim 5, characterized in that, After melting, the casting is carried out by bottom pouring and argon gas protection is applied above the ingot mold. The casting temperature is 1480~1520℃. After casting, air cooling is used, and the air cooling rate is 10~15℃ / s.

7. The method for preparing high-resistance austenitic corrosion-resistant steel according to claim 5, characterized in that, The smelting process employs vacuum induction melting.

8. The method for preparing high-resistance austenitic corrosion-resistant steel with high resistance to hydrogen embrittlement according to claim 7, characterized in that, The vacuum induction melting process has a melting vacuum degree of ≤5Pa and a melting temperature of 1550℃~1580℃.

9. The method for preparing high-resistance austenitic corrosion-resistant steel according to claim 8, characterized in that, Ni-Sc master alloy is added at the end of the vacuum induction melting process, and 0.001%~0.005% Mg by mass is added for inclusion modification treatment.

10. The method for preparing high-resistance austenitic corrosion-resistant steel according to claim 9, characterized in that, The mass fraction of Sc in the Ni-Sc master alloy is 15%~20%.

11. The method for preparing high-resistance austenitic corrosion-resistant steel according to claim 9, characterized in that, The charging sequence for the smelting is as follows: first, Fe, Cr, Ni, Mn and Si base materials are added. After the base materials are completely melted, Fe-Nb master alloy and Fe-Ti master alloy are added in sequence and kept at a constant temperature. Finally, Ni-Sc master alloy is added 5 to 8 minutes before tapping.

12. The method for preparing high-resistance austenitic corrosion-resistant steel according to claim 9, characterized in that, After the inclusion modification treatment, the size of the composite inclusions formed in the corrosion-resistant steel is <2μm.

13. The method for preparing high-resistance austenitic corrosion-resistant steel with high resistance to hydrogen embrittlement according to claim 5, characterized in that, The forging process conditions include: a forging temperature range of 1100℃~1200℃, a billet heating temperature of 1200℃~1250℃ before forging, and a holding time of 2h~4h.

14. The method for preparing high-resistance austenitic corrosion-resistant steel with high resistance to hydrogen embrittlement according to claim 5, characterized in that, The hot rolling start temperature is 1100℃~1200℃, the final rolling temperature is 900℃~1050℃, and the total hot rolling reduction is 70%~90%.

15. The method for preparing high-resistance austenitic corrosion-resistant steel according to claim 14, characterized in that, The thickness of the sheet after hot rolling is 12mm~15mm.

16. The method for preparing high-resistance austenitic corrosion-resistant steel against hydrogen embrittlement according to claim 5, characterized in that, The solution treatment temperature is 1000℃~1200℃, and the holding time is 20min~40min.

17. The method for preparing high-resistance austenitic corrosion-resistant steel with high resistance to hydrogen embrittlement according to claim 16, characterized in that, The cooling rate after solution treatment is greater than 70°C / s.

18. The method for preparing high-resistance austenitic corrosion-resistant steel against hydrogen embrittlement according to claim 5, characterized in that, The prestress of the uniaxial tensile prestressing treatment is 5%~15%.

19. A hydrogen-containing component, characterized in that, The hydrogen-resistant component is made of the high hydrogen embrittlement resistant austenitic corrosion-resistant steel as described in any one of claims 1 to 4.

20. The hydrogen-containing component according to claim 19, characterized in that, The hydrogen-containment components are high-temperature hydrogen transport pipelines, hydrogenation reactor liners, or structural components of hydrogenation devices.

21. A steel component for power transmission and transformation, characterized in that, The power transmission and transformation steel components are made of the high hydrogen embrittlement resistant austenitic corrosion-resistant steel as described in any one of claims 1 to 4.

22. The hydrogen-containing component according to claim 21, characterized in that, The power transmission and transformation steel components include poles, supports, or power fittings used in power transmission and transformation projects.

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