A method for reducing the hydrogen embrittlement sensitivity of nickel-based corrosion-resistant alloys

Abstract

This invention provides a method for reducing the hydrogen embrittlement sensitivity of nickel-based corrosion-resistant alloys, relating to the technical field of regulating the hydrogen embrittlement resistance of corrosion-resistant alloys. The method is as follows: After solution annealing at 980-1060℃, the nickel-based corrosion-resistant alloy undergoes overall or surface cold deformation treatment, followed by aging heat treatment at 700-800℃. The overall cold deformation treatment is performed by cold drawing or cold rolling, with a deformation ratio of 5-30%. The surface deformation treatment is performed by shot peening or laser shock peening, or a combination of shot peening and laser shock peening, forming a deformation-affected layer with a thickness of 0.1-0.5 mm. Compared to other traditional methods, this invention creatively adds overall cold deformation and surface cold deformation between traditional solution and aging treatments. Through the combined regulation of cold deformation and aging, small-angle grain boundaries are increased, dislocation traps are introduced, and precipitation behavior is altered, thereby increasing hydrogen traps, reducing the alloy's hydrogen embrittlement sensitivity, and improving the alloy's hydrogen resistance.

Description

Technical Field

[0001] This invention relates to the technical field of regulating the hydrogen embrittlement resistance of corrosion-resistant alloys, and particularly to a method for reducing the hydrogen embrittlement sensitivity of nickel-based corrosion-resistant alloys. Background Technology

[0002] Nickel-based alloys, due to their excellent high-temperature mechanical properties, are widely used in aerospace and other industries as high-temperature alloys. Their outstanding resistance to localized corrosion and stress corrosion is also a key material widely used in oil and gas drilling and production equipment. In oil and gas development, environments containing saturated water vapor, associated petroleum gas, and natural gas are referred to as wet associated gas or wet natural gas environments.

[0003] In wet natural gas environments, water, gas, hydrocarbons, and solids coexist in a multiphase medium with internal interactions, making alloy corrosion behavior highly complex. Oil and gas field production water or condensate also contains high levels of Cl. - CO2 and H2S can form weak acids when dissolved in water, causing electrochemical corrosion of the alloy and easily leading to hydrogen-induced cracking and sulfide stress corrosion cracking.

[0004] Hydrogen in hydrogen-induced cracking promotes crack initiation and propagation in alloys, leading to hydrogen embrittlement. The δ-phase distributed along grain boundaries in nickel-based corrosion-resistant alloys promotes the propagation of hydrogen-embrittled cracks; therefore, reducing the volume fraction of the strengthening phase can also reduce the alloy's hydrogen embrittlement tendency. Currently, it is common practice to control the content of δ-phase promoting elements such as Nb, perform solution treatment at a temperature higher than that of aerospace nickel-based superalloys, and then adjust the volume fractions of the δ-phase and γ'' and γ'' phases slightly above the peak aging temperature to obtain microstructures and properties more suitable for oil and gas extraction. This approach can, to some extent, control or reduce the alloy's hydrogen embrittlement tendency.

[0005] However, for a given alloy grade, there are clear control specifications for alloy composition and heat treatment regime. Therefore, how to further reduce the hydrogen embrittlement sensitivity of nickel-based corrosion-resistant alloys and effectively enhance their hydrogen embrittlement resistance is a hot topic and a difficult point in the research of nickel-based corrosion-resistant alloys.

[0006] Chinese patent CN108998649A discloses a method to improve the hydrogen resistance of iron-nickel-based precipitation-strengthened austenitic alloys by increasing the proportion of special grain boundaries. The method involves solution treatment and heat treatment of J75 nickel-based alloys, followed by 4-6% cold rolling deformation, then holding at a temperature higher than the solution treatment temperature, water cooling, and aging. However, the composition of this method shows relatively low corrosion resistance and high-temperature performance. Although the proportion of special grain boundaries in the alloy can be increased through low-deformation deformation + short-term solution treatment at higher temperatures + aging, coordinating deformation and short-term high-temperature holding has certain limitations, especially for large-sized components in engineering applications.

[0007] Chinese patent CN110564948A discloses a method for transforming some straight grain boundaries in an alloy into serrated grain boundaries through heat treatment with controlled cooling rate. This method can transform high-energy straight grain boundaries into low-energy serrated grain boundaries, which improves the alloy's resistance to hydrogen embrittlement to a certain extent. However, it has strict requirements on the cooling rate, which needs to be cooled to 900-920℃ at a cooling rate of 1-6℃ / min. For nickel-based corrosion-resistant alloys with high Nb content, such as 718, δ phase is easily precipitated after temperature-controlled cooling. It is suitable for J100 nickel-based alloys, and its application range is limited.

[0008] Chinese patent CN115679230A discloses a surface treatment process to improve the hydrogen embrittlement resistance of nickel-based corrosion-resistant alloys. The process requires laser melting, solution treatment, and aging treatment. The elongation of the laser-melted sample is higher than that of the control group. However, laser melting requires the use of a laser to melt and solidify the surface layer quickly. After a long period of high-temperature solution treatment, the workpiece surface will inevitably oxidize and form an oxide scale. Laser melting also has a certain impact on surface roughness. The melted layer is easily partially or completely removed during subsequent oxide scale removal and surface finishing processes, which limits its effectiveness.

[0009] Chinese patent CN109234500A discloses a method for improving the stress corrosion resistance of iron-nickel-based corrosion-resistant alloy oil well pipes. The method involves preparing the oil well pipe using a two- or more-pass Pilger cold rolling process. By controlling the deformation rate of the final cold rolling pass to at least 56.5% and then slowly cooling the prepared oil well pipe to room temperature after the final cold rolling pass, the residual stress of the material is eliminated or significantly reduced without significantly altering its macroscopic mechanical properties. This improves its resistance to stress corrosion cracking in H2S media environments. This method requires a final rolling pass deformation of over 50% and is only applicable to non-age-hardening solid solution-strengthened iron-nickel-based alloys that require residual stress control, do not contain age-hardening elements such as Nb, Al, and Ti, and whose strength level can only be further improved through cold work hardening.

[0010] This invention provides a method for reducing the hydrogen embrittlement sensitivity of nickel-based corrosion-resistant alloys. The method involves performing overall or partial surface deformation treatment on the nickel-based alloy in the solid solution state to obtain a deformation-affected layer, followed by aging treatment. This results in the technical effects of increasing small-angle grain boundaries, introducing dislocation traps, and changing precipitation behavior. The increased hydrogen traps can improve the hydrogen resistance of the corrosion-resistant alloy. Summary of the Invention

[0011] The technical problem this invention aims to solve is that current nickel-based corrosion-resistant alloys, under given alloy grades, are difficult to effectively reduce hydrogen embrittlement sensitivity due to the influence of alloy composition and heat treatment specifications, resulting in limited improvement in the hydrogen resistance of corrosion-resistant alloys. Some processes are limited to alloys with fixed compositions, sometimes exhibiting poor high-temperature performance and corrosion resistance. Furthermore, methods for improving stress corrosion cracking resistance in H2S media environments are unpredictable in their applicability to directly improve the hydrogen embrittlement resistance of corrosion-resistant alloys. Additionally, these methods may not be applicable to nickel-based alloys in a solid solution state, leading to different selection of targets for reducing hydrogen embrittlement sensitivity.

[0012] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0013] A method for reducing the hydrogen embrittlement sensitivity of nickel-based corrosion-resistant alloys, the method being as follows:

[0014] S1, Solution Annealing

[0015] The nickel-based corrosion-resistant alloy was subjected to solution annealing to obtain the treated nickel-based corrosion-resistant alloy.

[0016] S2, Overall or surface cold deformation

[0017] The nickel-based corrosion-resistant alloy treated with S1 is subjected to overall or surface cold deformation treatment to obtain a cold-deformed alloy.

[0018] S3, Timeliness

[0019] Aging heat treatment was performed on the cold-deformed alloy of S2 to obtain a nickel-based corrosion-resistant alloy with reduced hydrogen embrittlement sensitivity.

[0020] Preferably, the chemical composition of the nickel-based corrosion-resistant alloy, by weight, contains less than 0.04% C, 17.0-24.0% Cr, 42.0-63.0% Ni, 3.0-7.0% Mo, 0.2-5.5% Nb, 0.5-2.5% Ti, 0.01-0.8% Al, less than 3% Cu, less than 1% Co, less than 1% W, with the remainder being Fe and unavoidable impurities.

[0021] Preferably, the solution annealing temperature in S1 is 980-1060℃, and the holding time is 0.5-2h.

[0022] Preferably, the overall cold deformation treatment in S2 is cold drawing or cold rolling, with a deformation ratio of 5-30%.

[0023] Preferably, the surface cold deformation treatment in S2 is shot peening or laser shock peening, or a combination of shot peening and laser shock peening.

[0024] Preferably, the process parameters for shot peening impact strengthening in S2 are: the shot diameter is 0.3-0.6 mm, the shot peening speed is 30-100 m / s, and the coverage is 100-400%.

[0025] Preferably, the laser shock peening process parameters in S2 are: laser wavelength 1064nm, pulse width 10ns, and pulse energy 10-25GW / cm². 2 The overlap rate of light spots is 10-50%.

[0026] Preferably, the surface of the cold-deformed alloy obtained by surface cold deformation treatment in S2 forms a deformation influence layer with a thickness of 0.1-0.5 mm.

[0027] Preferably, the aging heat treatment in S3 is performed at a temperature of 700-800℃ for 2-8 hours.

[0028] Preferably, in the nickel-based corrosion-resistant alloy with reduced hydrogen embrittlement sensitivity in S3, the proportion of small-angle grain boundaries is not less than 45%, and the grain boundaries are free of chain-like δ phase.

[0029] Preferably, the nickel-based corrosion-resistant alloy with reduced hydrogen embrittlement sensitivity in S3 is pre-charged with hydrogen in a 0.5 mol / L H2SO4 + 0.25 g / L thiourea solution for 24 h. The hydrogen embrittlement sensitivity is evaluated by comparing the changes in elongation of the pre-charged and uncharged samples in a slow tensile test. δ =(δ0-δ H The results of the ) / δ0) test show that the hydrogen embrittlement sensitivity I δ Compared to traditional solution and aging treatments that do not involve overall or surface cold deformation, the reduction can reach about 30%.

[0030] Preferably, by adjusting the cold rolling, shot peening / laser impact cold deformation, and subsequent aging process after solution treatment, small-angle grain boundaries are increased, dislocation traps are introduced to increase hydrogen traps, and precipitation behavior is changed to reduce the δ phase which is detrimental to hydrogen resistance, thereby improving the alloy's hydrogen resistance.

[0031] Technical principle of the invention:

[0032] Nickel-based corrosion-resistant alloys possess outstanding resistance to localized corrosion and stress corrosion, making them key materials widely used in oil and gas drilling and production equipment. The nickel-based corrosion-resistant alloy used in this invention, by mass percentage, contains less than 0.04% C, 17.0-24.0% Cr, 42.0-63.0% Ni, 3.0-7.0% Mo, 0.2-5.5% Nb, 0.5-2.5% Ti, 0.01-0.8% Al, less than 3% Cu, less than 1% Co, less than 1% W, with the remainder being Fe and unavoidable impurities. The presence of certain amounts of Nb, Ti, and Al elements in the alloy allows for the formation of γ' and γ″ strengthening phases during the aging process after solution treatment, resulting in higher strength.

[0033] Nickel-based corrosion-resistant alloys undergo cold deformation treatment after solution heat treatment and before aging treatment. Cold deformation increases small-angle grain boundaries, introduces dislocation traps to increase hydrogen traps, and alters precipitation behavior to reduce the δ phase, which is detrimental to hydrogen resistance, thereby improving the alloy's hydrogen resistance. In this invention, solution treatment refers to heating the corrosion-resistant alloy to 980-1060℃ to dissolve the alloying elements into the microstructure, followed by cooling to form a supersaturated solid solution. To improve the alloy's hydrogen resistance, this invention combines cold deformation and aging to increase small-angle grain boundaries, introduce dislocation traps, and alter precipitation behavior, thereby increasing hydrogen traps and reducing the alloy's hydrogen embrittlement sensitivity. Specifically, for nickel-based corrosion-resistant alloy bars / wires and plates suitable for deformation, this invention employs a cold-drawing and cold-rolling integral cold deformation method. Through deformation with a 5-30% deformation ratio, high-density vacancies, dislocations, and other defects are introduced into the alloy. In the subsequent aging process, this invention controls the combination of aging temperature and time. On one hand, some of the deformed microstructure recovers under heating at 700-800℃, increasing the number of small-angle characteristic grain boundaries. On the other hand, due to the control of aging temperature and time, some stable dislocations within the grains are retained, increasing reversible hydrogen traps. Furthermore, the strain storage energy provided by deformation can reduce the nucleation energy of the strengthening phase, promoting the aging precipitation process. The aging precipitation is more dispersed, and aging can be completed at lower temperatures and in shorter times, making it less likely to produce chainless δ phases. By using a treatment method of solution treatment followed by deformation and then aging, small-angle grain boundaries can be increased, dislocation traps can be introduced to increase hydrogen traps, and precipitation behavior can be altered to reduce δ phases that are detrimental to hydrogen resistance, thereby improving the alloy's hydrogen resistance.

[0034] Since hydrogen-induced cracking initially begins at the material surface, this invention also utilizes high-energy shot peening and / or nanosecond laser shock peening to obtain a 0.1-0.6 mm deformation-affected layer. This method is applicable not only to regular materials such as rods / wires and plates, but also to complex corrosion-resistant alloy workpieces with bends, steps, etc. High-energy shot peening and / or nanosecond laser shock peening can increase small-angle grain boundaries and introduce dislocation traps to increase hydrogen traps on the workpiece surface, altering precipitation behavior and reducing the δ phase, which is detrimental to hydrogen resistance, thereby improving the alloy's hydrogen resistance. To ensure this surface wear-resistant strengthening effect, this invention employs high-energy shot peening and / or nanosecond laser strengthening to perform localized surface deformation treatment on the raceway. Shot peening uses a shot diameter of 0.3-0.6 mm, a shot velocity of 30-100 m / s, and a coverage of 100-400%. Laser shock peening uses a laser wavelength of 1064 nm, a pulse width of 10 ns, and a pulse energy of 10-25 GW / cm². 2 The overlap rate of light spots is 10-50%.

[0035] The above technical solution has at least the following advantages compared with the existing technology:

[0036] The present invention proposes a method to reduce the hydrogen embrittlement sensitivity of nickel-based corrosion-resistant alloys. For nickel-based corrosion-resistant alloys after solution annealing, the method increases small-angle grain boundaries, introduces dislocation traps, and changes precipitation behavior through a combination of cold deformation and aging, thereby increasing hydrogen traps and reducing the hydrogen embrittlement sensitivity of the alloy.

[0037] The nickel-based corrosion-resistant alloy of this invention has a wide range of compositional options. The synergistic selection of the composition and content of alloying elements will cause the microstructure to gradually change and develop in the direction of improving resistance to hydrogen embrittlement and strength during heat treatment and cold deformation.

[0038] This invention creatively adds overall cold deformation between traditional solid solution and aging treatments to the nickel-based corrosion-resistant alloy, introducing high-density defects such as vacancies and dislocations into the alloy. This lays a solid foundation for the subsequent aging treatment to retain some stable dislocations inside the grains, increase small-angle grain boundaries and reversible hydrogen traps in dislocations, and avoid the generation of chainless δ phases.

[0039] This invention creatively adds surface cold deformation to the nickel-based corrosion-resistant alloy between traditional solution treatment and aging treatment. The 0.1-0.6 mm deformation-affected layer formed increases small-angle grain boundaries on the workpiece surface, introduces dislocation traps to increase hydrogen traps, and reduces the δ phase which is detrimental to hydrogen resistance, thereby achieving the technical objective of improving the alloy's hydrogen resistance.

[0040] In summary, compared with other traditional methods, the method of this invention creatively adds overall cold deformation and surface cold deformation between traditional solid solution and aging treatment. By adjusting the temperature and time of aging treatment, small-angle grain boundaries are increased, dislocation traps are introduced, and hydrogen traps are increased, thereby changing the precipitation behavior to reduce the δ phase which is detrimental to hydrogen resistance, and ultimately improving the hydrogen resistance of the alloy. Attached Figure Description

[0041] 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.

[0042] Figure 1 This is an EBSD CSL grain boundary distribution map of a nickel-based corrosion-resistant alloy prepared according to a method for reducing the hydrogen embrittlement sensitivity of nickel-based corrosion-resistant alloys in Example 1 of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0044] Example 1

[0045] A method for reducing the hydrogen embrittlement sensitivity of nickel-based corrosion-resistant alloys, the method being as follows:

[0046] S1, Solution Annealing

[0047] The nickel-based corrosion-resistant alloy was cut to obtain a 2mm thick nickel-based corrosion-resistant alloy, and then subjected to solution annealing treatment at 1050℃ for 1.5h, followed by water cooling; the treated nickel-based corrosion-resistant alloy was obtained; wherein: the chemical composition of the nickel-based corrosion-resistant alloy, by weight, contains 0.02% C, 18.82% Cr, 53.51% Ni, 2.86% Mo, 5.30% Nb, 1.05% Ti, 0.52% Al, less than 0.05% Cu, less than 0.03% W, with the remainder being Fe and unavoidable impurities;

[0048] S2, Overall cold deformation

[0049] The nickel-based corrosion-resistant alloy after S1 treatment was subjected to overall cold deformation treatment. Before the cold deformation treatment, the surface needed to be polished. The overall cold deformation treatment was cold rolling deformation, and the rolling deformation amount was set to 10% to obtain the cold-deformed alloy.

[0050] S3, Timeliness

[0051] The cold-deformed alloy of S2 was subjected to aging heat treatment at a temperature of 760℃ for 12 hours to obtain a nickel-based corrosion-resistant alloy with reduced hydrogen embrittlement sensitivity.

[0052] In this embodiment, the nickel-based corrosion-resistant alloy treated with this method has no chain-like δ-phase at the grain boundaries, and its EBSD is as follows: Figure 1 As shown, the proportion of small-angle grain boundaries is 71%.

[0053] Example 2

[0054] A method for reducing the hydrogen embrittlement sensitivity of nickel-based corrosion-resistant alloys, the method being as follows:

[0055] S1, Solution Annealing

[0056] The nickel-based corrosion-resistant alloy was cut to obtain a 2mm thick nickel-based corrosion-resistant alloy, and then subjected to solution annealing treatment at 1050℃ for 1.5h, followed by water cooling; the treated nickel-based corrosion-resistant alloy was obtained; wherein: the chemical composition of the nickel-based corrosion-resistant alloy, by weight, contains 0.02% C, 18.82% Cr, 53.51% Ni, 2.86% Mo, 5.30% Nb, 1.05% Ti, 0.52% Al, less than 0.05% Cu, less than 0.03% W, with the remainder being Fe and unavoidable impurities;

[0057] S2, surface cold deformation

[0058] The S1-treated nickel-based corrosion-resistant alloy underwent surface cold deformation treatment. Prior to the surface cold deformation treatment, surface polishing was required. The surface cold deformation treatment consisted of shot peening and impact strengthening to obtain the cold-deformed alloy. The shot peening and impact strengthening process parameters were: shot diameter of 0.4 mm, shot velocity of 50 m / s, and coverage of 150%.

[0059] S3, Timeliness

[0060] The cold-deformed alloy of S2 was subjected to aging heat treatment at a temperature of 780℃ for 10 hours to obtain a nickel-based corrosion-resistant alloy with reduced hydrogen embrittlement sensitivity.

[0061] In this embodiment, the treated nickel-based corrosion-resistant alloy has no chain-like δ-phase at the grain boundaries, and the proportion of small-angle grain boundaries differs slightly to 64%. Its EBSD pattern is similar to... Figure 1Similarly, this embodiment will not be repeated.

[0062] Example 3

[0063] A method for reducing the hydrogen embrittlement sensitivity of nickel-based corrosion-resistant alloys, the method being as follows:

[0064] S1, Solution Annealing

[0065] The nickel-based corrosion-resistant alloy was cut to obtain a 2mm thick nickel-based corrosion-resistant alloy, and then subjected to solution annealing treatment at 1050℃ for 1.5h, followed by water cooling; the treated nickel-based corrosion-resistant alloy was obtained; wherein: the chemical composition of the nickel-based corrosion-resistant alloy, by weight, contains 0.02% C, 18.82% Cr, 53.51% Ni, 2.86% Mo, 5.30% Nb, 1.05% Ti, 0.52% Al, less than 0.05% Cu, less than 0.03% W, with the remainder being Fe and unavoidable impurities;

[0066] S2, surface cold deformation

[0067] The S1-treated nickel-based corrosion-resistant alloy underwent surface cold deformation treatment, which was laser shock strengthening. The laser shock strengthening process parameters were: laser wavelength 1064 nm, pulse width 10 ns, and pulse energy 20 GW / cm². 2 The overlap rate of the light spot is 10%; a deformation influence layer with a thickness of 0.1-0.5 mm is formed on the surface of the cold-deformed alloy obtained by surface cold deformation treatment;

[0068] S3, Timeliness

[0069] The cold-deformed alloy of S2 was subjected to aging heat treatment at 750℃ for 15 hours to obtain a nickel-based corrosion-resistant alloy with reduced hydrogen embrittlement sensitivity. In this embodiment, the treated nickel-based corrosion-resistant alloy showed no chain-like δ-phase at grain boundaries, although the proportion of small-angle grain boundaries differed slightly, reaching 67%. Its EBSD pattern was consistent with... Figure 1 Similarly, this embodiment will not be repeated.

[0070] Unlike Examples 1-3 above, the control group of Examples 1-3 was not subjected to overall cold deformation or surface cold deformation, but was subjected to only 1050℃×1.5h solution treatment + 780℃×8h aging heat treatment according to the specifications.

[0071] Hydrogen embrittlement resistance test of control group and examples: Pre-charged with hydrogen for 24 hours using 0.5 mol / L H₂SO₄ + 0.25 g / L thiourea solution, the change in elongation of pre-charged and uncharged samples in slow tensile tests was compared to evaluate hydrogen embrittlement sensitivity (I0.05). δ =(δ0-δ HThe experimental results of δ0 are shown in Table 1 below. By comparing the experimental group and the control group, the effects of cold rolling, shot peening / laser shock cold deformation after solution treatment, and subsequent aging regime regulation were achieved. This increased the number of small-angle grain boundaries, introduced dislocation traps to increase hydrogen traps, and changed the precipitation behavior to reduce the δ phase which is detrimental to hydrogen resistance, thus improving the hydrogen resistance of the alloy.

[0072] Table 1

[0073]

[0074] The present invention proposes a method to reduce the hydrogen embrittlement sensitivity of nickel-based corrosion-resistant alloys. For nickel-based corrosion-resistant alloys after solution annealing, the method increases small-angle grain boundaries, introduces dislocation traps, and changes precipitation behavior through a combination of cold deformation and aging, thereby increasing hydrogen traps and reducing the hydrogen embrittlement sensitivity of the alloy.

[0075] The nickel-based corrosion-resistant alloy of this invention has a wide range of compositional options. The synergistic selection of the composition and content of alloying elements will cause the microstructure to gradually change and develop in the direction of improving hydrogen embrittlement sensitivity and strength during heat treatment and cold deformation.

[0076] This invention creatively adds overall cold deformation between traditional solid solution and aging treatments to the nickel-based corrosion-resistant alloy, introducing high-density defects such as vacancies and dislocations into the alloy. This lays a solid foundation for the subsequent aging treatment to retain some stable dislocations inside the grains, increase small-angle grain boundaries and reversible hydrogen traps in dislocations, and avoid the generation of chainless δ phases.

[0077] This invention creatively adds surface cold deformation to the nickel-based corrosion-resistant alloy between traditional solution treatment and aging treatment. The 0.1-0.6 mm deformation-affected layer formed increases small-angle grain boundaries on the workpiece surface, introduces dislocation traps to increase hydrogen traps, and reduces the δ phase which is detrimental to hydrogen resistance, thereby achieving the technical objective of improving the alloy's hydrogen resistance.

[0078] In summary, compared with other traditional methods, the method of this invention creatively adds overall cold deformation and surface cold deformation between traditional solid solution and aging treatment. By adjusting the temperature and time of aging treatment, small-angle grain boundaries are increased, dislocation traps are introduced, and hydrogen traps are increased, thereby changing the precipitation behavior to reduce the δ phase which is detrimental to hydrogen resistance, and ultimately improving the hydrogen resistance of the alloy.

[0079] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method of reducing the susceptibility of a nickel-based corrosion resistant alloy to hydrogen embrittlement, characterized by, The method is specifically as follows: S1, solid solution annealing The nickel-based corrosion-resistant alloy is subjected to solid solution annealing treatment to obtain a treated nickel-based corrosion-resistant alloy; the chemical composition of the nickel-based corrosion-resistant alloy is measured by weight, containing 0.04% or less of C, 17.0-24.0% of Cr, 42.0-63.0% of Ni, 3.0-7.0% of Mo, 0.2-5.5% of Nb, 0.5-2.5% of Ti, 0.01-0.8% of Al, 3% or less of Cu, 1% or less of Co, 1% or less of W, the remainder being Fe and inevitable impurities; S2, overall or surface cold deformation The nickel-based corrosion-resistant alloy treated in S1 is subjected to overall or surface cold deformation treatment to obtain a cold-deformed alloy; the overall cold deformation treatment is cold drawing or cold rolling, and the deformation ratio is 5-30%; the surface cold deformation treatment is shot peening impact strengthening or laser impact strengthening, or a combination of shot peening impact strengthening and laser impact strengthening; S3, aging The cold-deformed alloy of S2 is subjected to aging heat treatment, the temperature of the aging heat treatment is 700-800℃, and the time is 2-8h, to obtain a nickel-based corrosion-resistant alloy with reduced hydrogen embrittlement sensitivity.

2. The method of reducing the susceptibility of a nickel-based corrosion resistant alloy to hydrogen embrittlement of claim 1, wherein, The temperature of the solid solution annealing treatment in S1 is 980-1060℃, and the holding time is 0.5-2h.

3. The method of reducing the susceptibility of a nickel-based corrosion resistant alloy to hydrogen embrittlement of claim 1, wherein, The process parameters of the shot peening impact strengthening in S2 are as follows: the shot diameter used is 0.3-0.6mm, the shot speed is 30-100m / s, and the coverage rate is 100-400%.

4. The method of reducing the susceptibility of a nickel-based corrosion resistant alloy to hydrogen embrittlement of claim 1, wherein, The process parameters of the laser shock peening in S2 are as follows: laser wavelength 1064 nm, pulse width 10 ns, pulse energy 10-25 GW / cm, and spot lap joint rate 10-50%. 2 , spot lap joint rate 10-50%.

5. The method of reducing the susceptibility of a nickel-based corrosion resistant alloy to hydrogen embrittlement of claim 1, wherein, The surface cold-deformed alloy obtained in S2 forms a deformed affected layer with a thickness of 0.1-0.5mm.

6. The method of reducing the susceptibility of a nickel-based corrosion resistant alloy to hydrogen embrittlement of claim 1, wherein, The nickel-based corrosion-resistant alloy with reduced hydrogen embrittlement sensitivity in S3 has a proportion of small-angle grain boundaries not less than 45%, and the grain boundaries are free of chain-like δ phase.

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