Method for manufacturing a nuclear reactor component and nuclear reactor component thus obtained

Abstract

Manufacturing process for a nuclear reactor component and nuclear reactor component thus obtained. The manufacturing process includes obtaining a nickel-based alloy strip with the following composition, in weight percentages: traces ≤ C ≤ 0.08%; traces ≤ Mn ≤ 0.35%; traces ≤ Si ≤ 0.35%; traces ≤ P ≤ 0.015%; traces ≤ S ≤ 0.015%; 17.0% ≤ Cr ≤ 21.0%; traces ≤ Co ≤ 1.0%; 2.80% ≤ Mo ≤ 3.30%; 4.75% ≤ Nb + Ta ≤ 5.50%; 0.65% ≤ Ti ≤ 1.15%; 0.20% ≤ Al ≤ 0.80%; traces ≤ Cu ≤ 0.30%; 50.0% ≤ Ni ≤ 55.0%; traces ≤ B ≤ 0.006%; the remainder being Fe and impurities resulting from the processing, desensitization annealing is carried out in a static furnace at an annealing temperature of 900°C or higher and / or 1050°C or lower for an annealing time of 1 min or higher and / or 180 min or lower. Figure for the abbreviation: Figure 1

Description

Title of the invention: Method for manufacturing a nuclear reactor component and nuclear reactor component thus obtained

[0001] The present invention relates to the field of nickel superalloys, and more precisely the nickel-based alloy known as INCONEL® 718 (or NC19FeNb) corresponding to the UNS N07718 standard, which is used, for example, to manufacture components of light water nuclear reactors (or LWR), for example structural components or components of nuclear fuel assemblies intended to be inserted into these light water nuclear reactors.

[0002] The classic chemical composition of the INCONEL®718 alloy (name which will subsequently be abbreviated to “alloy 718”) is as follows: - traces < C < 0.08%; - traces < Mn < 0.35%; - traces < If < 0.35%; - traces < P < 0.015%; - traces < S < 0.015%; 17.0% < Cr < 21.0%; - traces < Co < 1.0%; 2.80 < Mo < 3.30%; 4.75% < Nb + Ta < 5.50%; 0.65% < Ti < 1.15%; 0.20% < Al < 0.80%; - traces < Cu < 0.30%; 50.0% < Ni < 55.0%; - traces < B < 0.006%;

[0003] the remainder being Fe and impurities resulting from the production.

[0004] Nuclear reactor components, particularly those of nuclear fuel assemblies, are often of limited size and thickness. Many of these components are manufactured by forming one or more metal sheets.

[0005] Such components require particularly high dimensional precision.

[0006] In addition, the environment of a light water nuclear reactor is very specific and imposes very specific stresses on alloy 718 linked, in particular, to radioactivity.

[0007] Light water nuclear reactor components are particularly exposed to the risk of environmentally assisted cracking, and in particular to the risk of stress corrosion cracking.

[0008] US5244515 and US5047093 propose a high heat treatment or “annealing” temperature to slow the propagation of stress corrosion cracks in a 718 alloy used in a nuclear application, to reduce the occurrence of the δ phase in the microstructure in the 718 alloy.

[0009] US8470106 discloses a crack desensitization annealing assisted by the environment, the desensitization annealing being carried out under a hydrogen atmosphere and aiming to eliminate as much as possible of the interstitial elements in the 718 alloy.

[0010] One of the aims of the invention is to make it possible to obtain an alloy whose resistance to environmentally assisted cracking, particularly under conditions likely to lead to stress corrosion, is improved, while preserving the mechanical properties, particularly in the aged state.

[0011] To this end, the invention proposes a method for manufacturing a component of a nuclear reactor, in particular a light water nuclear reactor, the manufacturing method comprising the steps of: - obtaining a strip made of nickel-based alloy with chemical composition, expressed in weight percentages: traces < C < 0.08%; traces < Mn < 0.35%; traces < Si < 0.35%; traces < P < 0.015%; traces < S < 0.015%; 17.0% < Cr < 21.0%; traces < Co < 1.0%; 2.80 < Mo < 3.30%; 4.75% < Nb + Ta < 5.50%; 0.65% < Ti < 1.15%; 0.20% < Al < 0.80%; traces < Cu < 0.30%; 50.0% < Ni < 55.0%; traces < B < 0.006%; the remainder being Fe and impurities resulting from the production; - carrying out a desensitization annealing of the strip in a static furnace to obtain an annealed strip, comprising maintaining the strip at an annealing temperature equal to or greater than 900°C, in particular equal to or greater than 920°C, preferably equal to or greater than 940°C and / or equal to or less than 1050°C, in particular equal to or less than 1000°C, preferably equal to or less than 980°C, for an annealing time equal to or greater than 1 min, in particular equal to or greater than 15 min, preferably equal to or greater than 30 min and / or equal to or less than 180 min; and - shaping the annealed strip to obtain the component.

[0012] Carrying out an annealing of the alloy 718 in the form of a metal strip and before shaping the strip, at a limited temperature and with an appropriate duration, makes it possible to increase the δ phase content of the microstructure of the alloy 718.

[0013] It has been found that such an increase in the δ phase content makes it possible to reduce the sensitivity to environmentally assisted cracking.

[0014] The increase in the δ phase content does not significantly degrade the ductility at room temperature of the 718 alloy obtained for easy shaping, with a high value, up to 40% or more, for elongation at break.

[0015] This has the advantage of maintaining low stress on the hot and cold transformation tools and / or thus allowing better dimensional accuracy of the strip. This good dimensional accuracy is important to obtain, particularly on nuclear fuel assembly components.

[0016] Carrying out the final solution annealing step in a static furnace and on the metal strip, preferably packaged in a coil, makes it possible to promote the appearance of the δ phase in a controlled manner, with economical implementation.

[0017] The strip is processed as a whole before shaping the strip to form a component, and preferably several components.

[0018] Carrying out the annealing step on the strip, i.e. after the transformation steps necessary to obtain the strip, such as hot forging, hot rolling and / or cold rolling, makes it possible to decouple the production of the strip and the annealing.

[0019] The strip is for example manufactured and preferably wound at a first manufacturing site, then transported to a second manufacturing site distant from the first manufacturing site, for example by road transport, rail transport, sea transport and / or air transport, then heat treated and shaped at the second manufacturing site to obtain one and preferably several components from the strip.

[0020] The annealing carried out on the metal strip before shaping it to obtain the component makes it possible to obtain a particular microstructure which is neither totally recrystallized nor restored, and which comprises a significant fraction of δ phase.

[0021] However, it makes it possible to maintain mechanical properties in the final product comparable to those of conventionally treated 718 alloys used by the nuclear industry, and which were previously thought not to contain any ô phase at all, as indicated for example in the article “The Roles of Thermal Mechanical Treatment and ô Phase in the Stress Corrosion Cracking of Alloy 718 in Primary Water” by M. Wang et al., Corrosion Science 160 (2019) 108168.

[0022] In particular examples, the manufacturing method comprises one or more of the following optional features, taken individually or in any technically possible combination:

[0023] - during the desensitization annealing step, the strip is heated from the temperature room temperature up to the annealing temperature and then maintained at the annealing temperature for the annealing time;

[0024] - the manufacturing process comprises, after the desensitization annealing step, a active cooling step of the annealed strip carried out before the shaping step, preferably at least as long as the temperature of the strip is equal to or greater than a cooling temperature, for example equal to 600°C;

[0025] - the desensitization annealing step is carried out under vacuum or under an atmosphere protective, for example a non-oxidizing atmosphere, in particular a non-oxidizing atmosphere formed of argon and / or hydrogen;

[0026] - the desensitization annealing step is carried out on the conditioned strip in the form of a coil;

[0027] - the strip has a thickness equal to or less than 0.70 mm, in particular a thickness equal to or less than 0.60 mm, preferably a thickness equal to or less than 0.30 mm;

[0028] - at the end of the desensitization annealing step, the δ phase content of the micro structure of the nickel-based alloy is equal to or greater than 0.1%, in particular equal to or greater than 1%, preferably equal to or greater than 3% and / or equal to or less than 17%, in particular equal to or less than 12%, preferably equal to or less than 8%;

[0029] - the shaping step comprises one or more sub-steps of planing, cutting, stamping, bending and / or machining

[0030] - the step of obtaining the strip comprises one or more of the following steps: obtaining an ingot made from the nickel-based alloy; carrying out a homogenization annealing of the ingot; hot transformation of the ingot to obtain a hot transformed product; cold transformation of the hot transformed product to obtain the strip, the cold transformation being carried out in a cold transformation step or a series of cold transformation sub-steps with an intermediate annealing sub-step between each cold transformation sub-step and the next; and / or an intermediate annealing step between the hot transformation step and the cold transformation step;

[0031] - the manufacturing process is carried out without annealing between the transformation step at cold and the desensitization annealing step.

[0032] - the manufacturing process comprises an aging annealing step implemented work after the desensitization annealing step, preferably carried out at a temperature equal to or greater than 500°C and / or equal to or less than 800°C and / or for a duration equal to or greater than 1 h and / or equal to or less than 100 h;

[0033] - the aging annealing step is carried out after the shaping step and / or during the formatting stage;

[0034] - the manufacturing process is carried out without annealing the nickel-based alloy between the step desensitization annealing and the aging annealing step;

[0035] - the manufacturing process is carried out without annealing without annealing of the nickel-based alloy after the desensitization annealing step;

[0036] - the component is a nuclear fuel assembly element, in particular an element of a spacer grid of a nuclear fuel assembly, an element of a mixing grid of a nuclear fuel assembly or a spring of a nuclear fuel assembly.

[0037] The invention also relates to a nickel-based alloy component of a nuclear reactor, in particular a light water reactor, produced according to a manufacturing method as defined above.

[0038] In exemplary embodiments, at the end of the desensitization annealing step, the δ phase content of the microstructure of the nickel-based alloy is equal to or greater than 0.1%, in particular equal to or greater than 1%, preferably equal to or greater than 3% and / or equal to or less than 17%, in particular equal to or less than 12%, preferably equal to or less than 8%.

[0039] The invention and its advantages will become apparent upon reading the following description, given solely as a non-limiting example, and made with reference to the appended drawings, [Fig.l] which illustrate steps of a method of manufacturing a nuclear reactor component.

[0040] As illustrated in [Fig.l], the manufacturing method aims to obtain a component C of a nuclear reactor, in particular a light water nuclear reactor, the component being made of alloy 718 and having a particular microstructure.

[0041] The manufacturing process comprises:

[0042] - a step E1 of obtaining a strip B made of alloy 718 of composition following chemical composition, expressed in weight percentages: traces < C < 0.08%; traces < Mn < 0.35%; traces < Si < 0.35%; traces < P < 0.015%; traces < S < 0.015%; 17.0% < Cr < 21.0%; traces < Co < 1.0%; 2.80 < Mo < 3.30%; 4.75% < Nb + Ta < 5.50%; 0.65% < Ti < 1.15%; 0.20% < Al < 0.80%; traces < Cu < 0.30%; 50.0% < Ni < 55.0%; traces < B < 0.006%; the remainder being Fe and impurities resulting from the elaboration; - a step E2 of carrying out an annealing of the strip B in a static furnace FS to obtain a heat-treated strip B, and - a step E3 of shaping the annealed strip B to obtain component C.

[0043] Step E1 of obtaining band B comprises for example one or more of the following steps: - a step Eli to obtain an ingot L of alloy 718; - a step E12 of carrying out a homogenization annealing of the ingot L; - a step E13 of hot transformation of the ingot L to obtain a product P hot transformed; - a step E14 of annealing after hot transformation applied to the hot transformed product P; - a step E15 of cold transformation of the hot-transformed product P and optionally annealed after hot transformation to obtain the strip B, the cold transformation step being carried out in a single cold transformation sub-step E151 or a series of cold transformation sub-steps E151, with an intermediate annealing sub-step E152 between each cold transformation sub-step E151 and the following one; and / or - a winding step E16 to condition the strip B in the form of a reel.

[0044] Preferably, step E1 of obtaining strip B comprises step E1 of obtaining an ingot, step E12 of carrying out a homogenization annealing of the ingot L, step E13 of hot transformation of the ingot L to obtain a hot transformed product P, step E14 of annealing after hot transformation and step E15 of cold transformation of the hot transformed product P.

[0045] In possible variants, the homogenization annealing step E12 is omitted, the hot transformation step E13 is omitted, the annealing step E14 after hot transformation and / or the cold transformation step E15 is omitted.

[0046] Step E1 1 of obtaining an ingot L comprises, for example, in a conventional manner, the production in the liquid state and the casting, in the form of an ingot L, of an alloy 718 of composition as mentioned above.

[0047] Typically, this elaboration is carried out by a process or a series of processes which give the alloy 718 a good purity in terms of chemical composition and inclusion cleanliness.

[0048] The production of alloy 718 in the liquid state in an induction furnace under vacuum (VIM), followed by the casting of an ingot which then undergoes remelting under electroconductive slag to improve its purity and inclusion cleanliness, is a non-limiting example of such a series of processes.

[0049] Where appropriate, step E12 of homogenization annealing of the ingot L, which is optional, is carried out for example at a homogenization temperature of between 1,000°C and 1,400°C and / or for a homogenization time of between 30 min and 24 h.

[0050] Step E12 of homogenization annealing of the ingot L is carried out in a static furnace.

[0051] Where appropriate, the hot transformation step E13 is carried out in a temperature range between 750°C and 1,200°C, for example by hot rolling and / or hot forging.

[0052] Preferably, the hot transformation step E13 is carried out with a rate of working (the ratio between the section after hot transformation and the section before hot transformation) of at least 0.5.

[0053] The hot transformation step E13 is preferably implemented so as to obtain a hot transformed product P having the shape of a strip or a plate.

[0054] When a step 14 of annealing after hot transformation is implemented, this is for example carried out at a hot transformation annealing temperature of between 750°C and 1,200°C and / or for a hot transformation annealing time of between 1 min and 5 h.

[0055] Such a step E14 of annealing after hot transformation, carried out after a hot transformation step, makes it possible to ensure that a homogeneous and reproducible microstructure is obtained regardless of the precise conditions of implementation of the hot transformation step E13.

[0056] Step E14 of annealing after hot transformation is carried out for example in a continuous furnace or a static furnace.

[0057] Cold transformation step E15 is carried out on the product P hot transformed during hot transformation step E13 and optionally annealed during annealing step E14 after hot transformation, to obtain band B.

[0058] The cold transformation step E15 is carried out by any type of cold transformation. The cold transformation step E15 comprises, for example, at least one cold rolling sub-step E151.

[0059] The cold transformation step E15 comprises, for example, a single cold rolling sub-step E151 or a series of cold rolling sub-steps E151 with an intermediate annealing sub-step El52 between each cold rolling step E151 and the next.

[0060] Each cold rolling sub-step E151 is carried out in one or more rolling passes. Each rolling pass corresponds to the passage of the product between two rollers of a rolling mill between which the thickness of the product P is reduced.

[0061] Each rolling pass has, for example, a reduction rate of at least 10%. The reduction rate is the difference between the area of ​​the section before rolling and the area of ​​the section after rolling, expressed as a percentage.

[0062] Where appropriate, each intermediate annealing sub-step 152 comprises heating the product P to a temperature equal to or greater than 940°C for a duration equal to or greater than 10 seconds.

[0063] Each intermediate annealing sub-step 152 makes it possible to restore ductility to the alloy 718 before the following cold transformation sub-step E151.

[0064] Each intermediate annealing sub-step El52 is carried out for example in a continuous furnace.

[0065] The cold transformation step E15 is for example carried out solely by cold rolling in a cold rolling sub-step E151 or a series of cold rolling sub-steps E151 alternating with intermediate annealing sub-steps E152.

[0066] Where appropriate, the winding step E16 is carried out in a winding device, for example arranged downstream of a rolling mill used during the cold transformation step E15, to recover the strip B at the outlet of this rolling mill and wind it in the form of a coil.

[0067] The strip B obtained at the end of the obtaining step E1 preferably has a thickness equal to or less than 0.70 mm, in particular a thickness equal to or less than 0.60 mm, preferably a thickness equal to or less than 0.30 mm.

[0068] The desensitization annealing step E2 is carried out on the strip B, preferably packaged in a coil, in a static furnace FS, to obtain an annealed strip B.

[0069] During the desensitization annealing step E2, the strip B is heated to an annealing temperature equal to or greater than 900°C, in particular equal to or greater than 920°C, preferably equal to or greater than 940°C and / or equal to or less than 1050°C, in particular equal to or less than 1000°C, preferably equal to or less than 980°C, and maintained at the annealing temperature for an annealing time equal to or greater than 1 min, in particular equal to or greater than 15 min, preferably equal to or greater than 30 min and / or equal to or less than 180 min.

[0070] The desensitization annealing step E2 is preferably carried out in the static furnace FS under a controlled atmosphere or under vacuum.

[0071] The controlled atmosphere is preferably a non-oxidizing atmosphere, formed for example from a neutral gas or a mixture of neutral gases such as argon (Ar), nitrogen (N2) and their mixtures, or a reducing atmosphere such as hydrogen (H2) or an Ar / H2 mixture.

[0072] The vacuum desensitization annealing is for example carried out at a pressure lower than 102 mbar.

[0073] In a variant, the desensitization annealing step E2 is carried out under an oxidizing atmosphere, provided that the desensitization annealing is followed by a pickling and / or peeling operation aimed at removing an oxidized layer which has formed on the surface of the strip during the desensitization annealing.

[0074] At the end of the desensitization annealing step E2, the δ phase content of the microstructure of the alloy 718 is equal to or greater than 0.1%, in particular equal to or greater than 1%, preferably equal to or greater than 3% and / or equal to or less than 17%, in particular equal to or less than 12%, preferably equal to or less than 8%.

[0075] Optionally, the manufacturing method comprises a step E21 of cooling- active development implemented at the end of desensitization annealing step E2.

[0076] Active cooling means that the annealed B-strip is cooled more quickly than if it were simply left in the open air, for example by forcing a heat exchanger. Active cooling of the B-strip is, for example, implemented by injecting cold neutral gas into the furnace enclosure.

[0077] The active cooling step E21 makes it possible to avoid precipitating the hardening phases in the microstructure of the alloy 718.

[0078] The active cooling step E21 is for example implemented between the desensitization annealing temperature and a cooling temperature strictly lower than the desensitization annealing temperature, and for example equal to 600°C.

[0079] Below the cooling temperature, cooling may be slower. For example, it may be carried out in ambient air.

[0080] Preferably, the active cooling step E21 is carried out under a non-oxidizing protective atmosphere, for example consisting of Ar, H2 with a dew point of -51°C or lower, or an Ar / H2 mixture.

[0081] The non-oxidizing protective atmosphere is for example removed as soon as the temperature of the strip reaches a venting temperature, for example equal to approximately 150°C.

[0082] The active cooling step E21 is preferably implemented on the strip B packaged in a reel.

[0083] After the desensitization annealing step E2, possibly followed by the active cooling step E21, the alloy 718 of the strip B is capable of undergoing shaping, in particular cold shaping.

[0084] The desensitization annealing step E2 is preferably the last annealing undergone by the alloy 718 during the manufacture of the component.

[0085] The shaping step E3 comprises, for example, cutting the strip B, stamping the strip B, folding the strip B and / or machining the strip B to form the component C. The shaping step E3 is optionally preceded by a step of planishing the strip B.

[0086] The component C is for example a spring R of a grid of a nuclear fuel assembly, or for example a plate of a grid of a nuclear fuel assembly formed of a plurality of intersecting plates delimiting cells, each cell being intended to receive a nuclear fuel rod, each plate comprising bosses D (rigid), springs R (elastic) formed in the plate and / or attached to the plate to transversely support the nuclear fuel rods and / or fins A, arranged for example on an upper edge and / or a lower edge of the plate to force a mixture of a fluid cooling flowing through the nuclear fuel assembly during nuclear reactor operation.

[0087] The component C is for example obtained by planing the strip B initially wound into a coil to obtain a flat strip B, then shaping the strip B, for example by cutting into the strip B and shaping by cutting, stamping and / or machining to form one or more springs R and / or plates comprising bosses D and / or springs R and / or fins A formed in the plate.

[0088] The manufacturing method optionally comprises an aging annealing step E4 implemented after the desensitization annealing step E2.

[0089] The aging annealing step E4 is implemented before the shaping step E3, after the shaping step E3 and / or during the shaping step E3, for example between sub-steps of the shaping step E3.

[0090] The aging annealing step E4 is carried out in one or more steps during which the 718 base alloy is maintained at an aging temperature of between 500°C and 800°C and / or for an aging time of between 1 h and 100 h.

[0091] The implementation of an aging annealing step E4 makes it possible to increase the hardness without modifying the quantity of phase δ obtained after the desensitization treatment.

[0092] Tests were carried out on metal strips made from a 718 alloy of composition, expressed in weight percentages: Cr = 19.0%; Mo = 3.0%; Nb + Ta = 5.15%, Ti = 0.90%; Al = 0.50%; Ni = 52%; the remainder being Fe and impurities resulting from the production.

[0093] Each strip was obtained by implementing a step E11 of obtaining an ingot L of alloy 718, a step E12 of carrying out a homogenization annealing of the ingot L, a step E13 of hot transformation of the ingot L to obtain a hot transformed product P, a step E14 of annealing after hot transformation applied to the hot transformed product P, a step E15 of cold transformation of the hot transformed product P and annealing after hot transformation to obtain the strip B, the cold transformation step being carried out in a single cold transformation sub-step E151 or a series of cold transformation sub-steps E151, with an intermediate annealing sub-step E152 between each cold transformation sub-step E151.

[0094] The strips then underwent different desensitization anneals (desensitization step E2), a shaping step E3 to form nuclear fuel assembly grid springs R and an aging anneal (aging step E4).

[0095] Measurements were carried out before and after aging annealing to de determine the Vickers hardness (Hv) of alloy 718 in R springs, as well as the phase volume fraction δ.

[0096] In the comparative example (not in accordance with the invention), the strip was annealed at a high temperature of 1060°C, which is higher than the solvus of the δ phase. In Examples 1 to 3 (in accordance with the invention), the strips were subjected to desensitization anneals at temperatures of 920°C, 940°C and 970°C respectively, which are lower than the solvus of the δ phase.

[0097] The results are presented in the table below.

[0098] [Tables 1] Annealing Before aging After aging Temperature Time Vickers hardness Hv Phase ô Vol. fraction Vickers hardness Hv Phase ô Vol. fraction Example without desensitization 1060°C 1 min 190 0% 470 0% Example 1 with desensitization 920°C 1 hour 340 6-8 % 470 6-8 % Example 2 with desensitization 940°C 1 hour 320 6-8 % 460 6-8 % Example 3 with desensitization 970°C 30 min 300 6-8 % 470 6-8 %

[0099] The results show a greater hardness when the strip has undergone a desensitization annealing step at a temperature between 920°C and 970°C, while retaining a significant fraction of δ phase, here between 6 and 8% in Examples 1 to 3, whereas the δ phase content is very low, and in particular practically zero, in the absence of desensitization as recommended, as illustrated by the comparative example.

[0100] The aging step makes it possible to gain in hardness without modifying the quantity of phase ô obtained after the desensitization treatment.

[0101] Thus, the desensitization annealing step, in particular in combination with the aging annealing step, makes it possible to obtain a product sufficiently provided with δ phase, while having sufficient hardness to fulfill its functions.

[0102] The fact of carrying out a desensitization annealing carried out at a relatively low desensitization annealing temperature and a desensitization annealing duration allowing a fraction of phase δ to remain in the 718 alloy, possibly subjected to partial work hardening due to the shaping carried out after Desensitization annealing is surprisingly effective in improving protection against crack initiation.

[0103] The proposed manufacturing method makes it possible to maintain a level of mechanical properties in the aged state similar to that obtained with high-temperature annealing, carried out at a temperature above 1050°C, i.e. above the solvus of the δ phase.

[0104] It goes without saying that in addition to the operations described which aim to obtain the characteristics and properties of alloy 718 aimed in particular at improving its resistance to the initiation and propagation of cracks, it is possible to carry out additional operations which are usual, such as dropping parts of the initial ingot whose properties would not be satisfactory in any case, pickling, straightening of the semi-finished products or of the final product, etc.

[0105] The main thing is that these operations do not lead to modifications of the microstructure of the alloy 718 which would go against obtaining the properties targeted by the invention on the final products.

Claims

Claims

1. A method of manufacturing a component of a nuclear reactor, in particular a light water nuclear reactor, the manufacturing method comprising the steps of: - obtaining a strip made of nickel-based alloy of chemical composition, expressed in weight percentages: traces < C < 0.08%; traces < Mn < 0.35%; traces < Si < 0.35%; traces < P < 0.015%; traces < S < 0.015%; 17.0% < Cr < 21.0%; traces < Co < 1.0%; 2.80 < Mo < 3.30%; 4.75% < Nb + Ta < 5.50%; 0.65% < Ti < 1.15%; 0.20% < Al < 0.80%; traces < Cu < 0.30%; 50.0% < Ni < 55.0%; traces < B < 0.006%; the remainder being Fe and impurities resulting from the production;- carrying out a desensitization annealing of the strip in a static furnace to obtain an annealed strip, comprising maintaining the strip at an annealing temperature equal to or greater than 900°C, in particular equal to or greater than 920°C, preferably equal to or greater than 940°C and / or equal to or less than 1050°C, in particular equal to or less than 1000°C, preferably equal to or less than 980°C, for an annealing time equal to or greater than 1 min, in particular equal to or greater than 15 min, preferably equal to or greater than 30 min and / or equal to or less than 180 min; and - shaping the annealed strip to obtain the component.;

2. The method of claim 1, wherein, in the desensitization annealing step, the strip is heated from room temperature to the annealing temperature and then maintained at the annealing temperature for the annealing time.

3. Method according to claim 1 or 2, comprising, after the desensitization annealing step, a step of active cooling of the annealed strip carried out before the shaping step, preferably at least as long as the temperature of the strip is equal to or greater than a cooling temperature, for example equal to 600°C.

4. A method according to any preceding claim, in wherein the desensitization annealing step is carried out under vacuum or under a protective atmosphere, for example a non-oxidizing atmosphere, in particular a non-oxidizing atmosphere formed of argon and / or hydrogen.

5. A method according to any preceding claim, wherein the desensitization annealing step is carried out on the strip packaged in the form of a coil.

6. A method according to any one of the preceding claims, wherein the strip has a thickness equal to or less than 0.70 mm, in particular a thickness equal to or less than 0.60 mm, preferably a thickness equal to or less than 0.30 mm.

7. Method according to any one of the preceding claims, in which, at the end of the desensitization annealing step, the δ phase content of the microstructure of the nickel-based alloy is equal to or greater than 0.1%, in particular equal to or greater than 1%, preferably equal to or greater than 3% and / or equal to or less than 17%, in particular equal to or less than 12%, preferably equal to or less than 8%.

8. A method according to any preceding claim, wherein the shaping step comprises one or more sub-steps of planing, cutting, stamping, bending and / or machining.

9. A method according to any one of the preceding claims, wherein the step of obtaining the strip comprises one or more of the following steps: - obtaining an ingot made from the nickel-based alloy; - carrying out a homogenization annealing of the ingot; - hot transformation of the ingot to obtain a hot transformed product; - cold transformation of the hot transformed product to obtain the strip, the cold transformation being carried out in one cold transformation step or a series of cold transformation sub-steps with an intermediate annealing sub-step between each cold transformation sub-step and the next; and / or - an intermediate annealing step between the hot transformation step and the cold transformation step.

10. A method according to claim 9, carried out without annealing between the step of cold transformation and the desensitization annealing step.

11. Method according to any one of the preceding claims, comprising an aging annealing step carried out after the desensitization annealing step, preferably carried out at a temperature equal to or greater than 500°C and / or equal to or less than 800°C and / or for a duration equal to or greater than 1 h and / or equal to or less than 100 h.

12. The method of claim 11, wherein the aging annealing step is performed after the shaping step and / or during the shaping step.

13. A method according to claim 11 or claim 12, without annealing the nickel-based alloy between the desensitization annealing step and the aging annealing step.

14. A method according to any preceding claim, without annealing the nickel-based alloy after the desensitization annealing step.

15. A method according to any preceding claim, wherein the component is a nuclear fuel assembly element, in particular an element of a spacer grid of a nuclear fuel assembly, an element of a mixing grid of a nuclear fuel assembly or a spring of a nuclear fuel assembly.

16. Nickel-based alloy component of a nuclear reactor, in particular a light water reactor, produced according to a manufacturing method according to any one of the preceding claims.

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