Nickel alloy composition having molten salt corrosion resistance, nickel alloy comprising same, and preparation method thereof

Abstract

The present invention relates to a nickel alloy composition having molten salt corrosion resistance, a nickel alloy comprising same, and a preparation method thereof. More specifically, the present invention relates to: a nickel alloy composition having molten salt corrosion resistance and containing, on the basis of the total alloy weight, 10-14 wt% of chromium (Cr), 3-14 wt% of molybdenum (Mo), and 4-15 wt% of tungsten (W), with the remainder comprising nickel; a nickel alloy having molten salt corrosion resistance and comprising the nickel alloy composition; and a method for preparing the nickel alloy having molten salt corrosion resistance. The method comprises the steps of: melting a nickel alloy composition to produce an ingot; hot rolling the ingot at 1150-1250°C; performing water cooling; performing a solution heat treatment at 1050-1250°C for 30 minutes to 4 hours; and performing air cooling or furnace cooling.

Description

Nickel alloy composition having molten salt corrosion resistance, nickel alloy including the same, and method for manufacturing the same

[0001] The present invention relates to a nickel alloy composition having molten salt corrosion resistance, a nickel alloy containing the same, and a method for manufacturing the same. More specifically, the invention relates to a composition capable of producing a nickel alloy with improved corrosion resistance, a nickel alloy containing the same, and a method for manufacturing the same capable of securing improved physical properties.

[0002] Molten salt reactors operate in highly corrosive high-temperature environments. Recently, the development of molten salt reactors using molten chloride as both coolant and nuclear fuel has been pursued in countries including Korea, the United States, and Denmark. Most commercial high-temperature structural materials currently in use suffer severe damage due to corrosion; consequently, lowering operating temperatures to mitigate this damage risks reducing the efficiency and economic viability of the molten salt reactor. Most commercial high-temperature materials corrode severely in high-temperature molten salt environments, causing structural problems such as reduced strength and internal porosity, which can threaten the safety of the reactor. Since the interior of equipment for molten salt reactors, such as reactor vessels and piping, is exposed to the molten salt environment while the exterior is exposed to the atmosphere, excellent resistance to atmospheric corrosion is also a required property for high-temperature structural materials used in molten salt reactors. However, molten salt corrosion and atmospheric corrosion exhibit a trade-off relationship depending on the Cr content, requiring the determination of an optimal composition suitable for use in both distinct environments.

[0003] Meanwhile, since the corrosion rate of structural materials is generally known to be faster in chlorides, it is necessary to develop innovative materials with significantly improved corrosion resistance in atmospheric and molten salt environments to use them for a long period without replacement in chloride-based molten salt reactors. Although nickel alloys are known to have excellent corrosion resistance in the molten salt atmosphere of chloride-molten salt reactors, commercial nickel alloys used as high-temperature structural materials contain more than 20 wt% Cr content to ensure corrosion resistance in atmospheric environments and mechanical strength at high temperatures.

[0004] For example, Korean Patent Application No. 10-2020-7022700 discloses an austenitic heat-resistant alloy, but high-temperature brittleness may increase if the Cr content is 20 wt% or more. Furthermore, due to such a high Cr content, the corrosion rate in a molten salt environment is very high, making it difficult to apply such an alloy to environments such as molten salt reactors. In other words, nickel alloys containing such a high Cr content exhibit reduced corrosion resistance due to the leaching of Cr in a molten salt atmosphere.

[0005] In addition, molten salt reactors currently under development overseas often consider fluoride-based molten salt, so there are currently no verified materials for chloride-based molten salt reactors being developed domestically. While the optimal Cr content in fluoride molten salt is known to be around 7 wt%, the optimal Cr content in chloride molten salt has not been studied in detail, and in particular, results regarding the ratio of Mo, W, and Cr that can improve corrosion resistance in nickel alloys have not been reported. Since these components have advantageous or disadvantageous effects on various properties, such as improved alloy strength, reduced ductility, decreased manufacturability, and adverse effects on strength, there is a problem in determining the appropriate amount for high-temperature long-term mechanical properties.

[0006] Therefore, if a nickel alloy with excellent corrosion resistance in a molten chloride environment and superior high-temperature mechanical properties is developed, it is expected to be widely applied in related fields.

[0007] Accordingly, one aspect of the present invention is to provide a nickel alloy composition that exhibits excellent corrosion resistance in a molten chloride environment and excellent high-temperature mechanical properties.

[0008] Another aspect of the present invention is to provide a nickel alloy comprising a nickel alloy composition having molten salt corrosion resistance according to the present invention.

[0009] Another aspect of the present invention is to provide a method for manufacturing a nickel alloy having excellent high-temperature mechanical properties and molten salt corrosion resistance using the nickel alloy composition of the present invention.

[0010] According to one aspect of the present invention, a nickel alloy composition having molten salt corrosion resistance is provided, comprising, based on the total weight of the alloy, 10 to 14 weight% of chromium (Cr); 3 to 14 weight% of molybdenum (Mo); 4 to 15 weight% of tungsten (W); and the remainder being nickel.

[0011] According to another aspect of the present invention, a nickel alloy having molten salt corrosion resistance comprising the nickel alloy composition of the present invention is provided.

[0012] According to another aspect of the present invention, a method for manufacturing a nickel alloy having molten salt corrosion resistance is provided, comprising the steps of: melting the nickel alloy composition of the present invention to produce an ingot; hot rolling the ingot at 1150 to 1250°C; water cooling; solution heat treatment at 1050°C to 1250°C for 30 minutes to 4 hours; and cooling by air cooling or furnace cooling.

[0013] According to the present invention, a nickel-based alloy comprising specific amounts of Cr, Mo, and W is provided, and based on the composition of the present invention, it exhibits excellent corrosion resistance in molten chloride corrosion and can also improve high-temperature mechanical properties.

[0014] Figure 1 shows the results of equilibrium phase calculations (Thermocalc) according to the ratio of Mo and W in a nickel-based alloy containing 12 wt% Cr, where Figure 1(a) is the case containing 4 wt% Mo and 12 wt% W, Figure 1(b) is the case containing 7 wt% Mo and 10 wt% W, and Figure 1(c) is the case containing 12 wt% Mo and 4 wt% W.

[0015] Figure 2 is a photograph showing the surface microstructure of the nickel alloys of the examples and comparative examples.

[0016] Figure 3 is a photograph showing the cross-sectional microstructure of the nickel alloys of the example and comparative example after NaCl-MgCl2 molten salt corrosion at 700°C for 200 hours.

[0017] Figure 4 shows the high-temperature tensile properties at 700°C of the nickel alloys of the examples and comparative examples manufactured by air cooling.

[0018] Figure 5 shows the high-temperature tensile properties at 700°C of nickel alloys of the examples and comparative examples prepared by furnace cooling. Compared to the air-cooled specimen, the furnace-cooled specimen shows a significant increase in elongation.

[0019] Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

[0020] According to the present invention, a nickel-based alloy containing specific amounts of chromium (Cr), molybdenum (Mo), and tungsten (W) is provided, and based on the composition of the present invention, excellent corrosion resistance in molten chloride salt corrosion and can also improve high-temperature mechanical properties.

[0021] More specifically, the nickel alloy composition having molten salt corrosion resistance according to the present invention comprises, based on the total weight of the alloy, 10 to 14 weight% of chromium (Cr); 3 to 14 weight% of molybdenum (Mo); 4 to 15 weight% of tungsten (W); and the remainder being nickel.

[0022] Meanwhile, the nickel alloy composition of the present invention may contain impurities that are inevitably included during the manufacturing process.

[0023] In the nickel alloy composition of the present invention, chromium (Cr) may be included in an amount of 10 to 14 weight%, for example, 11 to 13 weight%, and if it is less than 10 weight%, atmospheric corrosion tends to increase, and if it exceeds 14 weight%, resistance to molten chloride corrosion may decrease.

[0024] In the nickel alloy composition of the present invention, molybdenum (Mo) may be included in an amount of 3 to 14 weight%, for example, 4 to 13 weight%, and if it is less than 3 weight% or more than 14 weight%, the resistance to molten chloride corrosion tends to be insufficient.

[0025] In the nickel alloy composition of the present invention, tungsten (W) may be included in an amount of 4 to 15 weight%, for example, 7 to 14 weight%, and when less than 4 weight% and more than 15 weight%, the resistance to molten chloride corrosion tends to be insufficient.

[0026] Furthermore, in the nickel alloy composition of the present invention, the ratio of chromium (Cr), molybdenum (Mo), and tungsten (W) also influences the improvement of resistance to molten chloride salt corrosion.

[0027] In the nickel alloy composition of the present invention, the weight ratio of tungsten (W) to molybdenum (Mo) may be 0.5 to 4, for example, 0.5 to 3, or 0.8 to 2.5.

[0028] Meanwhile, the weight ratio of chromium (Cr) to tungsten (W) may be 1.0 to 2.5, for example, 1.0 to 2, or 1.0 to 1.5.

[0029] In addition, the weight ratio of chromium (Cr) to molybdenum (Mo) may be 1 to 3.5, for example, 1.0 to 3.

[0030] Furthermore, the nickel alloy composition having molten salt corrosion resistance according to the present invention may additionally include at least one of aluminum (Al), titanium (Ti), hafnium (Hf), niobium (Nb), tantalum (Ta), manganese (Mn), carbon (C), and iron (Fe).

[0031] For example, the nickel alloy composition having molten salt corrosion resistance of the present invention may comprise 0.1 to 1 weight% aluminum (Al), 0.1 to 3 weight% titanium (Ti), 0.05 to 1 weight% hafnium (Hf), 0.05 to 1 weight% niobium (Nb), tantalum (Ta), or a combination thereof, 0.1 to 1 weight% manganese (Mn), 0.01 to 0.1 weight% carbon (C), and 0 to 1 weight% iron (Fe).

[0032] According to another aspect of the present invention, a nickel alloy having molten salt corrosion resistance comprising the nickel alloy composition of the present invention is provided, and, for example, a nickel alloy made of the nickel alloy composition of the present invention is provided.

[0033] At this time, the use of the nickel alloy is not particularly limited, but, for example, it may be for structural materials of a molten salt reactor, and the nickel alloy may be for manufacturing a reactor vessel that contains molten salt for melting nuclear fuel. In this case, the molten salt reactor, which is the reactor vessel containing molten salt, may be a type of reactor that replaces conventional solid nuclear fuel by melting nuclear fuel in molten chloride, which is a form of salt melted at high temperatures, and utilizing it as fuel and coolant for the reactor.

[0034] According to another aspect of the present invention, a method for manufacturing a nickel alloy with excellent high-temperature mechanical properties using the nickel alloy composition of the present invention is provided.

[0035] More specifically, the method for manufacturing a nickel alloy having molten salt corrosion resistance according to the present invention may comprise the steps of: melting a nickel alloy composition to produce an ingot; hot rolling the ingot at 1150 to 1250°C; water cooling; solution heat treatment at 1050°C to 1250°C for 30 minutes to 4 hours; and cooling by air cooling or furnace cooling.

[0036] However, the method for manufacturing the nickel alloy of the present invention does not exclude the performance of any additional steps between each step.

[0037] First, in the step of manufacturing an ingot by melting a nickel alloy composition, the composition related to the nickel alloy composition is as described above, and the ingot can be manufactured using a vacuum induction melting (VIM) method.

[0038] Specifically, the dissolution chamber is under high vacuum (1×10 -5In an atmosphere of 0.5 torr, an induced current is applied to primarily melt the alloying elements, and then a deoxidizing agent such as aluminum or silicon is added. Trace elements, particularly nitrogen, are added to the molten metal when melting is almost complete, and a sample for compositional analysis is taken. Once melting is complete, the molten metal is poured into a rectangular mold at 1500°C and tapped, and the oxide layer on the surface is mechanically processed to produce an ingot.

[0039] Next, the step of hot rolling the ingot manufactured in the step of manufacturing the ingot above is performed.

[0040] In the present invention, hot rolling is preferably performed at a temperature of 1150 to 1250°C for 0.5 to 2 hours. If the temperature is outside the above range, that is, below 1150°C, the purpose of solution annealing cannot be sufficiently achieved, and if the temperature exceeds 1250°C, the size of the prior-γ phase crystal grains increases too much, which may cause problems that degrade the mechanical properties of the final product.

[0041] After hot rolling, a water quenching step is performed to improve mechanical properties and stabilize the microstructure.

[0042] Next, a solution treatment step is performed. More specifically, the solution treatment step is performed by solution treatment at 1050°C to 1250°C for 30 minutes to 4 hours.

[0043] If the above solution treatment is performed at a temperature below 1050°C, the diffusion rate is slow, so the solution treatment may not be completed completely; if it is performed at a temperature above 1250°C, the grain size may increase too much, causing a problem that degrades the mechanical properties of the final product. In addition, if the above solution treatment is performed for less than 30 minutes, there is a problem that there is not enough time for the solution treatment, and if it is performed for more than 4 hours, a problem of grain growth may occur.

[0044] Subsequently, a cooling step by air cooling or furnace cooling is performed on the solution-treated alloy. Preferably, in the present invention, when furnace cooling is performed, the elongation can be improved without reducing the tensile strength at high temperatures.

[0045] The present invention will be explained in more detail below through specific embodiments. The following embodiments are merely examples to aid in understanding the present invention and do not limit the scope of the present invention.

[0046] Examples

[0047] 1. Derivation of a composition for improving the corrosion resistance of nickel alloys

[0048] In order to develop a Ni alloy with excellent corrosion resistance and structural integrity in molten chloride salts, the first step was to determine an appropriate Cr content within the Ni alloy that exhibits excellent corrosion resistance in a molten chloride salt environment. Since corrosion resistance in molten chloride salts tends to decrease when the Cr content is 20 wt% or more based on the total weight of the Ni alloy, the Cr concentration in the Ni alloy was considered to be 16 wt% or less in this embodiment. 'Ni alloy' and 'nickel alloy' can be used interchangeably, and 'nickel-based alloy' refers to an alloy in which nickel serves as the matrix, but can also be used interchangeably.

[0049] To evaluate the combination of Cr, Mo, and W that can secure molten salt corrosion resistance in Ni alloys, Ni model alloys were prepared by adding 10 wt% of each element based on the total weight of the alloy, and the molten salt corrosion resistance was evaluated.

[0050] 200g of Ni model alloy was melted and manufactured using VAR (Vacuum Arc Melting), and subsequently, a portion of the melted specimen was cold-rolled and heat-treated at 1200℃ followed by water cooling to produce a specimen of size 20 × 300 × 1.5t (width 20mm, length 300mm, thickness 1.5mm).

[0051] Each Ni model alloy was evaluated for corrosion at 700°C for 200 hours in a molten NaCl-MgCl2 chloride atmosphere, and HASTELLOY® N (Haynes International) alloy was evaluated for comparison.

[0052] Table 1 below shows the composition of the Ni model alloy and the weight change after molten salt corrosion. In Table 1 and the following examples, “Bal.” refers to the amount of balance that makes the total composition 100 wt%.

[0053] [Table 1] Composition of Nickel Model Alloy and Weight Change After Molten Salt Corrosion Evaluation

[0054]

[0055] * Unit: Weight %

[0056] As a result, as can be seen in Table 1 above, molten salt corrosion resistance was significantly reduced in specimens with 10 wt% Cr added to Ni, whereas it was improved in specimens with 10 wt% Mo and W added, respectively. In particular, specimens with 10 wt% Mo and W added to Ni-Cr (10 wt%) showed a significant increase in molten salt corrosion resistance compared to Ni-Cr (10 wt%) specimens. Microstructural analysis of the cross-sections of the specimens after molten salt corrosion confirmed that Mo and W exhibit different mechanisms of corrosion resistance within the specimens. Mo significantly reduced the depth of uniform Cr depletion in the Ni alloy, but some corrosion of Ni particles occurred; in contrast, W showed uniform Cr depletion thickness in the Ni alloy, but almost no corrosion of Ni particles occurred. Based on this, it is expected that molten salt corrosion resistance can be improved in Ni-Cr alloy systems mixed with appropriate amounts of Mo and W.

[0057] 2. Manufacture of nickel alloys

[0058] Nickel alloys are manufactured by mixing each alloy composition element, melting it to produce an ingot, and then hot-rolling and water-cooling the produced ingot. Through solution heat treatment of the hot-rolled alloy, nickel-based alloys exhibiting excellent molten salt corrosion resistance can be produced.

[0059] More specifically, the alloy composition elements of the nickel alloy consisted of nickel as the base, carbon, chromium, molybdenum, tungsten, manganese, aluminum, titanium, hafnium, niobium, and tantalum, and vacuum induction melting (VIM) was used for the manufacture of the ingots. The melted ingots were then produced through hot rolling. Hot rolling was performed at a temperature of 1200°C. At 1200°C, hot-rolled materials with a cumulative decomposition rate of 80% or more could be obtained from all alloy ingots. Meanwhile, it was confirmed that at temperatures above 1250°C, the grain size increased excessively, which could cause problems that degrade the mechanical properties of the final product. The solution treatment was carried out at a temperature between 1100°C and 1200°C. The solution treatment was performed for one hour to ensure sufficient time to redissolve any unwanted precipitates formed in the hot-worked product.

[0060] Meanwhile, the cooling rate was carried out under two conditions: air cooling and furnace cooling without heating in the heat treatment furnace. Specimens with dimensions of 70 × 300 × 5.2t (width 70 mm, length 300 mm, thickness 5.2 mm) were prepared.

[0061] [Table 2] Alloy composition of nickel-based alloy examples

[0062]

[0063] * Unit: Weight %

[0064] Since Nb and Ta have the same effect within the Ni alloy, it is calculated as the sum of Nb and Ta.

[0065] In selecting the above nickel alloy composition, the Cr content was selected to be 7 wt% or more of Hastelloy N of Comparative Example 4 to increase atmospheric oxidation resistance. In addition, the Cr content was selected to be 15 wt% or less to consider resistance to molten chloride corrosion.

[0066] Based on the fact that the nickel model alloy with a Cr content of 10 wt% applied in the preliminary experiment 1 above exhibited chloride molten salt corrosion resistance similar to or better than Hastelloy N, 12 wt% was selected as an exemplary Cr content. In designing the composition of the nickel-based alloy resistant to chloride molten salt corrosion, the mixing and ratio of Mo and W are key, and through thermodynamic equilibrium calculations, the composition was designed to exhibit structural integrity at 700°C, the operating temperature of the molten salt reactor.

[0067] According to thermodynamic calculation results using ThermoCalc software (Thermo-Calc Software AB), nickel alloys containing 12 wt% Cr and 3 to 14 wt% Mo and W basically contain M6C as a precipitate. The thermodynamic calculation results for a representative alloy composition are shown in Figure 1. For solution heat treatment, the contents of Mo and W were designed within a range where the formation temperature of M6C does not significantly exceed 1200°C. In addition, the design was based on verifying the stable temperatures and fractions of the Sigma and Mu phases, which are known to affect high-temperature properties. Since the fraction of the Sigma or Mu phase becomes very high when the amount of Mo increases significantly, it was designed to a maximum of 14 wt%.

[0068] Figure 2 shows the low-magnification (× 200) microstructure of each alloy after hot rolling and final heat treatment, confirmed using a scanning electron microscope (SEM). The alloys of Comparative Examples 1 and 2 exhibited a large microstructure with a grain size of approximately 100 μm, while the remaining nickel alloys exhibited a microstructure with a grain size of several tens of μm. The generated carbides were mostly molybdenum carbides of the M6C type, and some chromium carbides were observed along the grain boundaries and some titanium carbides were observed within the grains.

[0069] 3. Corrosion Assessment

[0070] To confirm the corrosion resistance of each nickel alloy specimen prepared in Section 2 above, a corrosion evaluation was performed in a molten chloride environment with a NaCl-MgCl2 eutectic composition. The corrosion evaluation was conducted in the high-temperature molten chloride by attaching a high-temperature furnace capable of conducting corrosion evaluations at high temperatures inside an environmentally controlled glove box. The conditions for the molten chloride corrosion evaluation were maintained at 700°C, with oxygen levels of 40 ppm or less and moisture levels of 4 ppm or less during the evaluation period. A NaCl-MgCl2 eutectic composition of 57 mol% NaCl and 43 mol% MgCl2 was used. Both thermal and chemical purification were applied to the molten chloride; the molten salt used for the corrosion evaluation was subjected to thermal purification through heat treatment at 300°C for 24 hours and chemical purification at 550°C for 48 hours after the addition of magnesium pellets.

[0071] For the corrosion evaluation of specimens in a high-temperature molten salt environment, one alumina crucible was used per specimen of each type, and the surface area of ​​the specimen per unit volume of molten salt was maintained constant in each test. All corrosion tests were performed under identical conditions, and commercial Hastelloy N specimens were evaluated alongside the standard specimens during the tests. After the molten salt corrosion evaluation at 700°C for 200 hours, the specimens were ultrasonically cleaned in water for 24 hours, and the weight change was measured after acid treatment using a 10% hydrochloric acid solution.

[0072] The chloride molten salt corrosion evaluation of each nickel alloy material prepared in this manner was analyzed through weight change and cross-sectional microstructure. The weight change and maximum Cr depletion depth of the specimens after molten salt corrosion at 700°C for 200 hours are shown in Table 3, and the cross-sectional microstructure after corrosion was confirmed using an electron microscope and is shown in Figure 3.

[0073] At this time, the weight change was calculated by the following equation (1), and the Cr deficiency depth was confirmed using electron microscope elemental analysis (SEM EDS, SEM Energy Dispersive Spectroscopy) images. The maximum Cr deficiency depth was measured in the part where the deepest Cr deficiency occurred in 10 cross-sectional microstructure electron microscope images.

[0074] [Table 3] Weight change of alloy and maximum Cr deficiency depth after 200 hours of NaCl-MgCl2 molten salt corrosion at 700℃

[0075]

[0076] As can be seen in Table 3 above, for all alloys of the embodiments of the present invention, the weight loss after molten salt corrosion is -0.9 mg / cm² 2 Excellent results were observed with a maximum Cr deficiency depth of less than 35㎛, and all showed excellent results. In particular, in the case of Comparative Example 2, the nickel alloy surface was corroded and could not maintain the original surface in part.

[0077] When Mo and W elements are appropriately included in a nickel alloy, they can be dissolved in nickel in a molten salt corrosion environment to improve the corrosion resistance of the nickel alloy structural material; however, if Mo and W components are included in excessive amounts beyond the scope of the present invention, it tends to weaken the corrosion resistance of the nickel alloy particles and reduce corrosion resistance in a molten salt corrosion environment.

[0078] Therefore, the ratio of Mo and W additions within nickel alloys is crucial for nickel alloys with molten salt corrosion resistance. This can be confirmed by the molten salt corrosion results of the nickel model alloys introduced earlier; in Ni-W and Ni-Cr-Mo model alloys, the weight loss was similar to or lower than that of the reference Hastelloy N, but the surface could not be maintained after corrosion, resulting in the corrosion of nickel particles.

[0079] 4. Tensile test

[0080] Tensile tests were performed on the alloys of the examples and comparative examples at 700°C, and the results are summarized in Table 4 below. The tensile test curves were then divided into Figure 4 (air cooling) and Figure 5 (furnace cooling).

[0081] At this time, the tensile strength test was performed according to the ASTM E8 SUB standard, and both yield strength and elongation were measured according to ASTM standards.

[0082] [Table 4]

[0083]

[0084] It was confirmed that specimens of each hot-rolled nickel alloy, furnace-cooled after solution heat treatment, tended to show improved yield strength and elongation compared to air-cooled specimens. As such, the nickel alloy of the present invention can improve elongation without decreasing tensile strength at high temperatures, depending on the heat treatment conditions, at the same alloy composition.

[0085] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and it will be obvious to those skilled in the art that various modifications and variations are possible within the scope of the technical concept of the present invention as described in the claims.

Claims

1. A nickel alloy composition having molten salt corrosion resistance, comprising, based on the total weight of the alloy, 10 to 14 weight% chromium (Cr); 3 to 14 weight% molybdenum (Mo); 4 to 15 weight% tungsten (W); and the remainder nickel.

2. A nickel alloy composition having molten salt corrosion resistance according to claim 1, wherein the weight ratio of tungsten (W) to molybdenum (Mo) is 0.5 to 4.

3. A nickel alloy composition having molten salt corrosion resistance according to claim 1, wherein the weight ratio of chromium (Cr) to tungsten (W) is 1.0 to 2.

5.

4. A nickel alloy composition having molten salt corrosion resistance according to claim 1, wherein the weight ratio of chromium (Cr) to molybdenum (Mo) is 1 to 3.

5.

5. A nickel alloy composition having molten salt corrosion resistance according to claim 1, further comprising at least one of aluminum (Al), titanium (Ti), hafnium (Hf), niobium (Nb), tantalum (Ta), manganese (Mn), carbon (C), and iron (Fe).

6. A nickel alloy composition having molten salt corrosion resistance according to claim 5, comprising 0.1 to 1 weight% aluminum (Al), 0.1 to 3 weight% titanium (Ti), 0.05 to 1 weight% hafnium (Hf), 0.05 to 1 weight% niobium (Nb), tantalum (Ta) or a combination thereof, 0.1 to 1 weight% manganese (Mn), 0.01 to 0.1 weight% carbon (C), and 0 to 1 weight% iron (Fe).

7. A nickel alloy having molten salt corrosion resistance comprising a nickel alloy composition of any one of claims 1 to 6.

8. In claim 7, the nickel alloy is a nickel alloy having molten salt corrosion resistance, suitable for use as a structural material for molten salt reactors.

9. In claim 7, the nickel alloy is a nickel alloy having molten salt corrosion resistance, for manufacturing a reactor vessel that accommodates molten salt for melting nuclear fuel.

10. A step of manufacturing an ingot by melting the nickel alloy composition of any one of claims 1 to 6; A step of hot rolling the ingot at 1150 to 1250℃; Water cooling step; A step of solution heat treatment at 1050℃ to 1250℃ for 30 minutes to 4 hours; and Cooling stage by air cooling or furnace cooling; A method for manufacturing a nickel alloy having molten salt corrosion resistance, comprising

Images