Antioxidant nickel-based alloys and methods

Abstract

The invention relates to a nickel-based superalloy comprising (in wt%): from 2.0% to 10.0% cobalt (Co), from 3.0% to 10.0% iron (Fe), from 14.0% to 18.0% chromium (Cr), from 4.5% to 5.3% aluminum (Al), from 3.0% to 7.0% tantalum (Ta), from 0.01% to 0.05% carbon (C), from 0.01% to 0.05% zirconium (Zr), from 0.05% to 1.0% hafnium (Hf), from 0.3% to 0.7% silicon (Si), from 0.01% to 0.3% of a total amount of rare earths, such as scandium (Sc), yttrium (Y), actinides and / or lanthanides, nickel (Ni), optionally from up to 3.0% tungsten (W), and / or from up to 2.0% molybdenum (Mo), and / or up to 2.0% rhenium (Re), and / or up to 0.05% boron (B).

Description

[0001] The present invention relates to nickel-based gamma-ray strengthened superalloys. The present invention also relates to their use in the manufacture of hot-spot components, such as, but not limited to, blades, vanes, heat shields, seals, and combustor components in gas turbines. The present invention also relates to their use as filler alloys for cladding and repairing components, such as, but not limited to, blades, vanes, heat shields, and combustor components in gas turbines. The present invention also relates to their use in single crystal form. The present invention also relates to their use in cladding single crystal substrates, such that their single crystal structure is retained within the added or clad volume.

[0002] Blade alloys are essential for critical components in aviation and land-based gas turbines, but are also used in other applications. The differences between blade alloys depend on the level of knowledge and production technology available at the time of their development, and on the relative emphasis on properties such as hot corrosion resistance, oxidation resistance, weldability, phase stability, and creep strength.

[0003] Blade alloys are used in single crystal (SX), directionally solidified (columnar, DS) or equiaxed (CC) form. Each grain is a crystal consisting primarily of a gamma phase matrix, which is essentially a solid solution of nickel (Ni) and elements such as cobalt (Co), iron (Fe), chromium (Cr), molybdenum (Mo), tungsten (W) and rhenium (Re). The particles of gamma' phase are essentially solid solutions of Ni3Al and elements such as titanium, tantalum (Ta) and niobium (Nb). Each grain is a two-phase crystal in which the gamma matrix and gamma' particles share the same crystal orientation and the boundaries between the matrix and the particles are coherent. The grain boundaries, if present, are typically modified by carbides and / or borides that provide cohesive strength. Zirconium (Zr) also contributes to grain boundary cohesion.

[0004] Creep strength is provided by elements that provide solid solution strengthening of the gamma matrix, such as molybdenum (Mo), tungsten (W), and rhenium (Re), and titanium (Ti), tantalum (Ta), and niobium (Nb), which provide solid solution strengthening of gamma particles. Aluminum (Al) provides creep strength because it increases the amount of gamma particles and because the presence of gamma particles concentrates the levels of molybdenum (Mo), tungsten (W), and rhenium (Re) in the matrix.

[0005] Effective internal cooling of the edges and tips of hot-stage gas turbine components is difficult to achieve, so a significant portion of the cooling air used in a gas turbine is consumed by dilution air, which mixes with the hot gas stream near the tips and edges to locally reduce its temperature and prevent excessive oxidation damage. Therefore, any improvement in the metal's temperature resistance translates into a reduction in dilution air usage, thereby increasing the gas turbine's thermal efficiency and, consequently, reducing CO2 emissions.

[0006] IN738LC is the standard for high hot corrosion resistance. It is the blade alloy of choice typically in gas turbines when high hot corrosion resistance is required.

[0007] CM247CC is manufactured using a low-sulfur process with sulfur (S) <5 ppm and is considered the standard for high oxidation resistance due to its ability to form protective alumina and effectively inhibit oxide flaking caused by sulfur. CM247CC is the blade alloy of choice when high oxidation resistance is required.

[0008] Edge14, manufactured using a low-sulfur process, is considered the standard for superior oxidation resistance due to its ability to form protective alumina and its ability to use a carefully crafted reactive element (rhenium (Re)) formulation based on hafnium (Hf), silicon (Si), zirconium (Zr), and yttrium (Y) to extremely effectively inhibit oxide scale flaking. Furthermore, the very high aluminum (Al) activity means a large margin for loss of the ability to reform the protective alumina. This very high Al activity also enables rapid selective oxidation of Al2O3, resulting in a thin oxide scale that better resists flaking.

[0009] STAL18SiLaY is considered the standard for high crack-free cladding capability, where the single-crystal structure is retained within the single-crystal substrate. This is provided by a moderate γ' content and a significant addition of silicon (Si), which provides good wetting between the cladding layers.

[0010] STAL18SiLaY is considered a standard for useful phase stability because no brittle phase formation was observed in service when it was used to repair oxidation-damaged single-crystal blades.

[0011] STAL18SiLaY is considered a standard for useful creep resistance because of its moderate levels of strengthening elements, 37 mol% γ′ content, the beneficial single-crystal structure achieved by cladding, and good experience when it was used to repair oxidation-damaged single-crystal blades.

[0012] Hot corrosion resistance is provided by chromium (Cr) and enhanced by silicon (Si). It is also important to allow up to moderate levels of molybdenum (Mo).

[0013] D. Goldschmidt, “Single-Crystal Blades Proc. from Materials for Advanced Power Engineering” (Part 1, 1994, pp. 661-674), teaches that the hot corrosion resistance of blade alloy SC16 having 16 wt% chromium (Cr) and 3 wt% molybdenum (Mo) is significantly lower than the hot corrosion resistance of blade alloy IN738LC having 16 wt% chromium (Cr) and 1.8 wt% molybdenum (Mo).

[0014] If the amount of alloying elements is too high, unwanted phases (UP) such as Sigma and Laves will form in service. Therefore, if excessive UP formation is to be avoided, an increase in the level of alloying elements other than chromium (Cr) must be accompanied by a reduction in chromium (Cr), which means a conflict between corrosion resistance and other properties. One specific effect of UP precipitation is a reduction in creep strength. Another effect is embrittlement of the blade alloy. Another effect is that if chromium (Cr) is trapped in chromium (Cr)-rich UP, oxidation resistance and corrosion resistance are reduced.

[0015] In the case of high-firing temperature gas turbines, it is generally accepted that high oxidation resistance means the ability to form a coherent and continuous Al2O3 layer in the oxide scale, as required to withstand metal temperatures of 1000°C or above. Furthermore, flaking of the oxide scale, caused by the ever-present sulfur contamination, must be suppressed. Furthermore, since each reformation represents a loss of aluminum (Al), a margin must be provided to prevent the loss of the ability to reform the protective aluminum oxide. Furthermore, the use of alloying elements such as titanium will lead to contamination of the Al2O3 layer, as titanium partially replaces the aluminum (Al) in the layer, making it less protective. Furthermore, the ability to rapidly and selectively oxidize the Al2O3 is advantageous, as this reduces the thickness of the oxide scale and makes it less susceptible to flaking.

[0016] The ability to form protective Al2O3 and the margin required to prevent aluminum (Al) loss due to oxide scale spalling is a complex function of the Al content and the combination of other alloying elements, which act synergistically to enhance or degrade this ability. In phase diagram calculations (CALPHAD), this ability is correlated with predicted Al activity. In the context of blade alloys, CALPHAD refers to the use of thermodynamic software (such as Thermocalc) to predict entities such as the partitioning of alloying elements between γ and γ'; liquidus, solidus, and γ' solvus temperatures; γ' content; risk of UP precipitation; and Al activity. Increased Al activity also means faster selective oxidation of the protective Al2O3.

[0017] The following observations can be found in the literature regarding the addition of alloying elements to improve oxidation resistance:

[0018] CA Barrett's "A Statistical Analysis of Elevated Temperature Gravimetric Cyclic Oxidation Data of 36 Ni- and Co-base Superalloys based on an Oxidation Attack Parameter NASA TM 105934" teaches that the ability to form a protective Al2O3 layer is provided by aluminum (Al), enhanced by chromium (Cr) and tantalum (Ta), slightly reduced by molybdenum (Mo) and tungsten (W), and significantly reduced by titanium (Ti) and niobium (Nb). This conclusion is based on extensive correlation studies of commercial and experimental blade alloys. This means that if the levels of chromium (Cr) and tantalum (Ta) are increased, or the levels of titanium (Ti) and niobium (Nb) are reduced, less aluminum (Al) is required to form the Al2O3 protective layer.

[0019] C. Sarioglu et al., "The Control of Sulfur Content in Nickel-Base Single Crystal Superalloys and its Effect on Cyclic Oxidation Resistance Proceedings," Superalloys 1996, teach that scale adhesion is severely reduced by impurity elements such as S, but that this effect can be neutralized by a combination of clean casting and the addition of a small, measured level of a reactive element, rhenium (Re). Without the addition of rhenium (Re), sulfur (S) must be well below 1 ppmw to avoid a deleterious effect on scale adhesion.

[0020] "Effect of Cycle Frequency on High-Temperature Oxidation Behavior of Alumina- and Chromia-Forming Alloys Oxidation of Metals" (58(1 / 2), 73-101(2002)) by BAPint et al. emphasizes the importance of sulfur (S) and further teaches that if a small amount of hafnium (Hf) and rare earth yttrium (Y) are combined, a beneficial rhenium (Re) effect is produced.

[0021] P. Caron et al., “Improvement of the Cyclic Oxidation Behaviour of Uncoated Nickel Based Single Crystal Superalloys Materials Proceedings” in “Materials for Advanced Power Engineering 1994”, teach that a beneficial rhenium (Re) effect occurs if a small amount of hafnium (Hf) and silicon (Si) are combined.

[0022] BAPint et al., "The use of Two Reactive Elements to Optimize Oxidation Performance of Alumina-Forming Alloys Materials" (High Temperature 20(3)375-386, 2003) teach that a significant rhenium (Re) effect can be obtained when using various rhenium (Re) formulations, an example of which is the excellent cyclic oxidation resistance seen in tests of Haynes-214 containing small amounts of zirconium (Zr), silicon (Si) and yttrium (Y).

[0023] JB Wahl, K. Harris' "Advances in Single Crystal Superalloys - Control of Critical Elements Proceedings" (7th Parsons conference, 2007) teaches that "a combination of hafnium (Hf) plus lanthanum and yttrium (Y)" rather than "hafnium (Hf) plus lanthanum or yttrium (Y)" has a beneficial effect on the cyclic oxidation resistance of CMSX-4.

[0024] It is generally accepted that the risk of hot tearing during additive manufacturing processes (such as laser cladding or powder bed fusion) and strain-age cracking during the subsequent dissolution process increases with increasing γ' content. It is also generally accepted that cladding in which a single crystal structure is maintained presents significant challenges. The cladding process itself is, in principle, capable of single crystal growth because it generates a high temperature gradient from the melt pool to the relatively cool substrate. However, in practice, it is difficult to suppress stray grain formation during the process. Furthermore, strain-age cracking is difficult to suppress for filler alloys with high γ' content, and most filler alloys with high oxidation resistance, which is related to the ability to form protective Al2O3, have high γ' content.

[0025] Most blade alloys can be characterized as classic industrial gas turbine (IGT) alloys, aerospace alloys or new IGT alloys, see Table 1.

[0026] The category of classic IGT alloys includes polycrystalline IN738LC, GTD-111, IN792 and single crystal SCA425 (Table 1).

[0027]

[0028] Table 1: Element additions in wt%, γ' content in mol% at 850°C, Al activity at 1273K (relative values). Yttrium (Y) on Cr2O3 means that protective Cr2O3 can be formed. na means not applicable.

[0029] These alloys have sufficient chromium (Cr) to form protective Cr2O3.

[0030] Blade alloys lacking this ability have relatively poor corrosion resistance. Typical IGT blade alloys lack the ability to form protective Al2O3, but SCA425, with 4 wt% aluminum (Al) supplemented with 16 wt% chromium (Cr), is borderline. In-house oxidation testing at 1273K shows that SCA425 will form a continuous layer of Al2O3 over most, but unfortunately not all, of its surface. Thermocalc, based on the TTNi8 database, has an aluminum (Al) activity of 3.1e-8 at 1273K. Classic IGT alloys are unsatisfactory for our purposes because they cannot form protective Al2O3.

[0031] Aerospace alloys include polycrystalline CM247CC for CC and DS casting, as well as single-crystal CMSX-4 and ReneN5 (see Table 1). Their low chromium (Cr) levels result in poor hot corrosion resistance. Due to their high aluminum (Al) and tantalum (Ta) levels, and despite their low chromium (Cr) levels, most can form protective Al2O3. Due to their poor corrosion resistance, aerospace alloys are unsuitable for our purposes. Furthermore, their high γ' content, typically in the 60 mol% to 70 mol% range, makes them difficult to process by laser cladding.

[0032] The new IGT alloys include polycrystalline STAL125CC1, single-crystal STAL15SX, laser-clad alloy STAL18SiLaY designed for cladding single-crystal substrates, and laser-clad alloy Edge14 designed for cladding polycrystalline and directionally solidified blade alloys, as shown in Table 1. These alloys have sufficient chromium (Cr) to form protective Cr2O3 at low and moderate temperatures (typically up to about 1173 K). In addition, they form protective Al2O3 at high temperatures (typically above about 1123 K) due to moderate to high levels of aluminum (Al) supplemented by significant levels of chromium (Cr) and tantalum (Ta).

[0033] A Cr2O3 protective layer is formed on top of the Al2O3 protective layer by STAL18SiLaY.

[0034] In STAL18SiLaY, the requirements for very high hot corrosion resistance, high oxidation resistance, good SX cladding ability, high phase stability, and at least moderate creep resistance are met by using moderate levels of aluminum (Al) and tantalum (Ta), high levels of chromium (Cr), various rhenium (Re) formulations, moderate levels of the matrix-reinforcing elements molybdenum (Mo) and tungsten (W), with specific restrictions on the Mo (Mo) level, the use of silicon (Si) to enhance corrosion and oxidation resistance, and maintaining a single-crystal structure within the cladding volume. The concept is that the moderate levels of aluminum (Al) and tantalum (Ta) are sufficient to form an adherent, continuous Al2O3 scale, thanks to support from the high levels of chromium (Cr), multiple rhenium (Re) effects, and the omission of deleterious elements such as titanium (Ti) and niobium (Nb). Consequently, the γ' content can be kept low enough to allow good weldability. Furthermore, the moderate levels of γ' and the moderate levels of matrix and γ'-reinforcing elements enable sufficient creep strength for the intended application. In addition, high levels of chromium (Cr), low levels of molybdenum (Mo) and added silicon (Si) enable very high hot corrosion resistance. In addition, from the perspective of phase stability, high levels of chromium (Cr) can be tolerated because the γ' content and the amount of matrix strengthening elements are moderate.

[0035] In STAL18SiLaY, crack-free cladding can be achieved within a surprisingly wide process window, despite the use of relatively large weld seams with widths and heights in the range of 1 mm to 2 mm. One reason for this is the moderate γ' content. Another reason, based on in-house experiments with identical process parameters involving different variants such as STAL18SiLaY with varying Si (Si) contents, is that silicon (Si) improves wetting between the layers, and this helps maintain the single-crystal structure. In the case of less Si (Si), but similar levels of γ' particles and strengthening elements, new grains and cracks are initiated in the interphase between the cladding layers, and these cracks propagate along the grain boundaries thus formed.

[0036] A recently developed new IGT cladding alloy, Edge14, was developed for excellent oxidation resistance. Relative to the new IGT alloys described above, cobalt (Co) is omitted and iron (Fe) is included. The high aluminum (Al) content in Edge14 would normally result in a high γ' content, which makes crack-free cladding very difficult. The addition of iron (Fe) affects the segregation of the aluminum (Al), resulting in more aluminum (Al) being present in the gamma matrix. This means that higher aluminum (Al) contents can be tolerated without making the γ' content so high that the alloy cannot be conveniently used for cladding. This also means that the concentration of aluminum (Al) in the gamma matrix is ​​increased. In CALPHAD terms, this translates into an increase in aluminum (Al) activity. At 1273K, the aluminum (Al) activity of Edge15 is 8.2*10 －8 In comparison, the aluminum (Al) activity of STAL18SiLaY is 4.9*10 －8 The aluminum (Al) activity of STAL15SX is 4.3*10 －8 The aluminum (Al) activity of SCA425 is 3.1*10 －8 It should be mentioned that STAL1SX showed similar oxidation resistance to CMSX-4 in laboratory testing and in use, while the grooved blade tips in CMSX-4 blades repaired with STAL18SiLaY showed less oxidation damage than the original CMSX-4 blade tips. It can be observed that the step in predicted aluminum (Al) activity from STAL18SiLaY to Edge14 is significantly higher than the significant step from STAL15SX to STAL18SLaY, and the step from borderline SCA425 to STAL15SX has high oxidation resistance confirmed in laboratory testing and in use.

[0037] Edge 14 has been successfully applied to CM247CC by cladding, and oxidation tests were conducted on samples consisting of Edge 14 blocks clad on a CM247CC substrate. It proved very difficult to induce oxidation damage in Edge 14. Finally, a 1000-hour test at 14,523 K (with a 1-hour soak) was used (higher levels would have caused incipient melting in CM247CC). Edge 15 material was still only slightly affected, while the CM247CC substrate was significantly damaged. Thus, Edge 14 offers excellent oxidation resistance. It can be observed that the excellent oxidation resistance is closely related to the very high aluminum (Al) activity.

[0038] Of these new IGT alloys, only STAL18SiLaY has a combination of at most moderate γ' content and significant silicon (Si) additions that enables high crack-free cladding capability, so that the single crystal structure in the single crystal substrate is retained in and within the cladding region. However, STAL18SiLaY does not provide aluminum (Al) activity consistent with the excellent oxidation resistance seen in Edge14.

[0039] It is therefore an object of the present invention to overcome these problems.

[0040] These problems are solved by the alloy according to claim 1 , the component according to claim 14 and the method according to claim 17 .

[0041] An object of the present invention is to provide a gamma-' reinforced nickel-base superalloy (referred to as blade alloy from here on) having a unique mixture of high hot corrosion resistance, excellent oxidation resistance, high crack-free cladding capability, useful phase stability, and useful creep resistance, wherein the single crystal structure in the substrate is retained in the crack-free cladding. This mixture can be used to repair oxidation-damaged single crystal components and, when used to prevent oxidation damage, can be used to manufacture hybrid single crystal components. The cladding region will also have high resistance to hot corrosion caused by corrosive agents (such as corrosive biofuels) or sea salt in the inlet air. In addition, the cladding region will not crack due to the formation of brittle phases. In addition, the cladding region is also able to manage the moderate creep loads typically seen in areas such as edges and tips on single crystal components where oxidation damage is prone to occur.

[0042] The present invention aims to provide a composite material with high hot corrosion resistance, excellent oxidation resistance, good crack-free coating, useful phase stability, and useful creep resistance, wherein the SX structure of the SX matrix is ​​preserved in the crack-free coating. In particular, the goal is to significantly improve oxidation resistance relative to STAL18SiLaY while maintaining the same levels of SX coating, phase stability, and creep resistance. In the present invention, a moderate reduction in hot corrosion resistance to "IN738LC levels" is acceptable.

[0043] The present invention relates to a nickel-based gamma-ray strengthened superalloy containing 2.0 wt% to 9.0 wt% of cobalt (Co), 3.0 wt% to 9.0 wt% of iron (Fe), 14.0 wt% to 18.0 wt% of chromium (Cr), 2.0 wt% to 5.0 wt% of molybdenum (Mo) + tungsten (W) + rhenium (Re), up to 2.0 wt% of molybdenum (Mo), 4.5 wt% to 5.3 wt% of aluminum (Al), 3.0 wt% to 1.0 wt% of tungsten (W) + rhenium (Re), 2.0 wt% to 5.0 wt% of chromium (Cr), 2.0 wt% to 5.0 wt% of tungsten (W) + rhenium (Re), 3.0 wt% to 1 ... 7.0wt% tantalum (Ta), between 0.02wt% and 0.3wt% carbon (C) + zirconium (Zr) + boron (B), at least 0.01wt% carbon (C), at least 0.01wt% zirconium (Zr), between 0.05wt% and 1.0wt% hafnium (Hf), between 0.3wt% and 0.7wt% silicon (Si) and between 0.05wt% and 0.3wt% total rare earths, such as Sc, yttrium (Y), actinides and lanthanides.

[0044] In the present invention, a judicious combination of iron (Fe) and cobalt (Co) is used to significantly improve oxidation resistance relative to STAL18SiLaY through a very significantly increased aluminum (Al) activity. Since the addition of iron (Fe) + cobalt (Co) affects the ability of aluminum (Al) to separate, aluminum (Al) can be increased when iron (Fe) and cobalt (Co) are added while the γ' content remains at the same level. Therefore, when forcing aluminum (Al) into the γ matrix, chromium (Cr) must be moderately reduced to avoid an increased tendency for UP formation. This is illustrated by the examples STAL17FeSiLaY, STAL16FeSiLaY and STAL15FeSiLaY in Table 1. For all clad alloys in Table 1, ThermoCalc simulations predict a γ' content of 37 mol% at an equilibrium temperature of 1123K. This is low enough to indicate good processability by cladding, but not so low as to indicate poor creep strength. In addition, the creep strength benefits from the SX structure. It should be noted that in this invention, the "Fe-substituting-Cobalt" formula used to design Edge14 has been updated to a more efficient "Cobalt-substituting-Cobalt-with-a-judicious-combination-of-Cobalt-and-Fe" formula. As the Cobalt-Fe + Iron level increases, the predicted Al activity also increases. Chromium (Cr) has been reduced relative to STAL18SiLaY. However, the Cr content is well above the classic 12.0 wt% Cr limit, as silicon (Si) has been added and molybdenum (Mo) is kept low to achieve high hot corrosion resistance.

[0045] The present invention also includes (in wt%):

[0046] 2.0% to 10.0% cobalt (Co),

[0047] 3.0% to 10.0% iron (Fe),

[0048] 14.0% to 18.0% chromium (Cr),

[0049] 4.5% to 5.3% aluminum (Al),

[0050] 3.0% to 7.0% tantalum (Ta),

[0051] 0.01% to 0.05% carbon (C),

[0052] 0.01% to 0.05% zirconium (Zr),

[0053] 0.05% to 1.0% hafnium (Hf),

[0054] 0.3% to 0.7% silicon (Si),

[0055] 0.01% to 0.3% of the total amount of rare earths, such as scandium (Sc), yttrium (Y), actinides and / or lanthanides,

[0056] Nickel (Ni),

[0057] Optionally:

[0058] Up to 3.0% tungsten (W), in particular 0.5% to 3.0% tungsten (W), and / or

[0059] Up to 2.0% molybdenum (Mo), in particular 0.4% to 2.0% molybdenum (Mo), and / or

[0060] Up to 2.0% rhenium (Re), in particular 0.3% to 2.0% rhenium (Re), and / or

[0061] Up to 0.05% boron (B), in particular 0.01 to 0.05% boron (B).

[0062] Compared to Edge 14, the single addition of yttrium (Y) has been replaced by a variety of rare earth additions. Furthermore, the silicon (Si) content has been significantly increased. Despite the lower aluminum (Al) content, the more efficient use of cobalt (Co) and iron (Fe) also results in very high aluminum (Al) activity. This reduction in Al results in a lower γ' content, which is required to facilitate cladding of the single crystal substrate, thereby creating a single crystal cladding region.

[0063] It may seem surprising that a modest increase in aluminum (Al) content can increase Al activity. However, oxidation resistance and Al activity are related to the Al content in the gamma matrix, and even in blade alloys capable of forming protective Al2O3, this is relatively low because most of the Al typically segregates into the gamma' particles. Since cobalt (Co) and iron (Fe) force more Al into the gamma matrix, the relative increase in gamma matrix Al content is significant.

[0064] According to the present invention, the alloy may include 2.0 wt% to 10.0 wt% of cobalt (Co), 3.0 wt% to 10.0 wt% of iron (Fe), 14.0 wt% to 18.0 wt% of chromium (Cr), 2.0 wt% to 5.0 wt% of molybdenum (Mo) + tungsten (W) + rhenium (Re), up to 2.0 wt% of molybdenum (Mo), 4.5 wt% to 5.3 wt% of aluminum (Al), 3.0 wt% to 7.0 wt% of tungsten (W), and 1.5 wt% of rhenium (Re). % tantalum (Ta), between 0.01wt% and 0.3wt% carbon (C) + zirconium (Zr) + boron (B), at least 0.01wt% carbon (C), at least 0.01wt% zirconium (Zr), between 0.05wt% and 1.0wt% hafnium (Hf), between 0.3wt% and 0.7wt% silicon (Si) and between 0.01wt% and 0.3wt% of the total rare earth content, such as scandium (Sc), yttrium (Y), actinides and lanthanides.

[0065] In addition, the alloy may include between 2.0wt% and 4.0wt% cobalt (Co), between 3.0wt% and 4.5wt% iron (Fe), between 16.5wt% and 18.0wt% chromium (Cr), between 0.6wt% and 1.0wt% molybdenum (Mo), between 2.0wt% and 3.0wt% tungsten (W), between 4.5wt% and 4.9wt% aluminum (Al), between 3.5wt% and 5.5wt% tantalum (Ta), between 0.01wt% and 0.05wt% carbon (C), between 0.01wt% and 0.05wt% zirconium (Zr), between 0.05wt% and 0.15wt% hafnium (Hf), between 0.3wt% and 0.7wt% silicon (Si), between 0.03wt% and 0.13wt% lanthanum (La), and between 0.03wt% and 0.13wt% yttrium (Y).

[0066] In a preferred embodiment referred to as STAL17FeSiLaY, the alloy may include 3.0wt% cobalt (Co), 4.0wt% iron (Fe), 17.0wt% chromium (Cr), 0.8wt% molybdenum (Mo), 2.5wt% tungsten (W), 4.7wt% aluminum (Al), 4.5wt% tantalum (Ta), 0.03wt% carbon (C), 0.03wt% zirconium (Zr), 0.1wt% hafnium (Hf), 0.5wt% silicon (Si), 0.1wt% lanthanum (La) and 0.1wt% yttrium (Y).

[0067] Alternatively, the alloy may include between 3.0 wt% and 5.0 wt% cobalt (Co), between 5.5 wt% and 6.5 wt% iron (Fe), between 15.5 wt% and 17.5 wt% chromium (Cr), between 0.6 wt% and 1.0 wt% molybdenum (Mo), between 2.0 wt% and 3.0 wt% tungsten (W), between 4.6 wt% and 5.1 wt% aluminum (Al), between 3.5 wt% and 5.6 wt% tungsten (W), between 1.5 wt% and 2.0 wt% tungsten (T), between 2.0 wt% and 3.0 wt% tungsten (T), between 3.5 wt% and 5.6 wt% tungsten (T), between 4.5 wt% and 5.6 wt% tungsten (T), between 5.5 wt% and 1.0 wt% tungsten (T), between 5.5 wt% and 1.0 wt% tungsten (T), between 6.5 wt% and 6.5 wt% tungsten (T), between 7.5 wt% and 8.5 wt% tungsten (T), between 8.5 wt% and 8.5 wt% tungsten (T), between 1. 0.5wt% tantalum (Ta), between 0.01wt% and 0.05wt% carbon (C), between 0.01wt% and 0.05wt% zirconium (Zr), between 0.05wt% and 0.15wt% hafnium (Hf), between 0.3wt% and 0.7wt% silicon (Si), as well as 0.03wt% and 0.13wt% lanthanum (La) and 0.03wt% and 0.13wt% yttrium (Y).

[0068] In a preferred embodiment referred to as STAL16FeSiLaY, the alloy may include 4.0wt% cobalt (Co), 6.0wt% iron (Fe), 16.0wt% chromium (Cr), 0.8wt% molybdenum (Mo), 2.5wt% tungsten (W), 4.9wt% aluminum (Al), 4.5wt% tantalum (Ta), 0.03wt% carbon (C), 0.03wt% zirconium (Zr), 0.1wt% hafnium (Hf), 0.5wt% silicon (Si), 0.1wt% lanthanum and 0.1wt% yttrium (Y).

[0069] Alternatively, the alloy may include between 6.0 wt% and 9.0 wt% cobalt (Co), between 7.5 wt% and 9.0 wt% iron (Fe), between 14.5 wt% and 15.5 wt% chromium (Cr), between 0.5 wt% and 1.0 wt% molybdenum (Mo), between 2.0 wt% and 3.0 wt% tungsten (W), between 4.8 wt% and 5.2 wt% aluminum (Al), between 3.5 wt% and 5.5 wt% tantalum (Ta), between 0.01 wt% and 0.05 wt% carbon (C), between 0.01 wt% and 0.05 wt% zirconium (Zr), between 0.05 wt% and 0.15 wt% hafnium (Hf), between 0.3 wt% and 0.7 wt% silicon (Si), and between 0.03 wt% and 0.13 wt% lanthanum (La) and 0.03 wt% and 0.13 wt% yttrium (Y).

[0070] In a preferred embodiment referred to as STAL15FeSiLaY, the alloy may include 8.0wt% cobalt (Co), 8.0wt% iron (Fe), 15.0wt% chromium (Cr), 0.8wt% molybdenum (Mo), 2.5wt% tungsten (W), 5.0wt% aluminum (Al), 4.5wt% tantalum (Ta), 0.03wt% carbon (C), 0.03wt% zirconium (Zr), 0.1wt% hafnium (Hf), 0.5wt% silicon (Si), 0.1wt% lanthanum and 0.1wt% yttrium (Y).

[0071] The blade alloy according to the invention is preferably processed using a clean production process.To ensure best results, the blade alloy should contain less than 5 ppm sulphur (S), preferably less than 1 ppm sulphur (S).

[0072] The alloy is preferably used to manufacture blades, vanes, heat shields or disks.

[0073] The alloy is suitable for casting (eg, equiaxed), and is preferably cast into a single crystal (SX) or columnar (DS) microstructure.

[0074] For the latter, a temperature gradient is used.

[0075] The alloy can be used as a powder for additive manufacturing. This can be done by welding using powder or wire made from this alloy, or by using cladding methods such as welding. Powder bed methods are also preferred.

[0076] The alloy can therefore be used to manufacture whole components or parts of components. This can preferably be used during the manufacture of new components.

[0077] Also preferred may be a method for repairing a component in which the alloy is used. In this case, the alloy is added to a substrate. The substrate may preferably have an SX or DS structure. In particular, in this case, the added material (powder bed, coating) is also accumulated in an SX or DS structure.

[0078] Alternatively, when the alloy is used as a base alloy, other embodiments may be designed to optimize compatibility with specific coatings. Alternatively, when the alloy is used as a filler alloy for cladding and weld repairs, other embodiments may be designed to optimize compatibility with specific base alloys and coatings.

Claims

1. A nickel-based superalloy comprising (in wt%): 2.0% to 10.0% cobalt (Co), 3.0% to 10.0% iron (Fe), 14.0% to 18.0% chromium (Cr), 4.5% to 5.3% aluminum (Al), 3.0% to 7.0% tantalum (Ta), 0.01% to 0.05% carbon (C), 0.01% to 0.05% zirconium (Zr), 0.05% to 1.0% hafnium (Hf), 0.3% to 0.7% silicon (Si), 0.01% to 0.3% of the total amount of rare earth elements such as scandium (Sc), yttrium (Y), actinides and / or lanthanides, Nickel (Ni), especially the balance is nickel (Ni), Optionally: Up to 3.0% tungsten (W), in particular 0.5% to 3.0% tungsten (W), and / or Up to 2.0% molybdenum (Mo), in particular 0.4% to 2.0% molybdenum (Mo), and / or Up to 2.0% rhenium (Re), in particular 0.3% to 2.0% rhenium (Re), and / or Up to 0.05% boron (B), in particular 0.01 to 0.05% boron (B).

2. The alloy according to claim 1, comprising 2.0% to 5.0% of molybdenum (Mo) and / or tungsten (W) and / or rhenium (Re), in particular comprising molybdenum (Mo) and tungsten (W) but not rhenium (Re).

3. The alloy according to claim 1 , comprising 0.02% to 0.2% of carbon (C) and / or zirconium (Zr) and / or boron (B), in particular carbon (C) and zirconium (Zr), and most particularly carbon (C), zirconium (Zr) and boron (B).

4. The alloy according to any one of claims 1, 2 or 3, comprising: 2.0% to 4.0% cobalt (Co), 3.0% to 4.5% iron (Fe), 16.5% to 18.0% chromium (Cr), 0.6% to 1.0% molybdenum (Mo), 2.0% to 3.0% tungsten (W), 4.5% to 4.9% aluminum (Al), 3.5% to 5.5% tantalum (Ta), 0.01% to 0.05% carbon (C), 0.01% to 0.05% zirconium (Zr), 0.05% to 0.15% hafnium (Hf), 0.3% to 0.7% silicon (Si), 0.03% to 0.13% lanthanum (La), and 0.03% to 0.13% yttrium (Y).

5. The alloy according to any one of claims 1, 2, 3 or 4, comprising: 3.0% cobalt (Co), 4.0% iron (Fe), 17.0% chromium (Cr), 0.8% molybdenum (Mo), 2.5% tungsten (W), 4.7% aluminum (Al), 4.5% tantalum (Ta), 0.03% carbon (C), 0.03% zirconium (Zr), 0.1% hafnium (Hf), 0.5% silicon (Si), 0.1% lanthanum (La), 0.1% yttrium (Y).

6. The alloy of claim 1, 2 or 3, comprising: 3.0% to 5.0% cobalt (Co), 5.5% to 6.5% iron (Fe), 15.5% to 17.5% chromium (Cr), 0.6% to 1.0% molybdenum (Mo), 2.0% to 3.0% tungsten (W), 4.6% to 5.1% aluminum (Al), 3.5% to 5.5% tantalum (Ta), 0.01% to 0.05% carbon (C), 0.01% to 0.05% zirconium (Zr), 0.05% to 0.15% hafnium (Hf), 0.3% to 0.7% silicon (Si), 0.03% to 0.13% lanthanum (La), and 0.03% to 0.13% yttrium (Y).

7. The alloy according to claim 1 or 6, comprising: 4.0% cobalt (Co), 6.0% iron (Fe), 16.0% chromium (Cr), 0.8% molybdenum (Mo), 2.5% tungsten (W), 4.9% aluminum (Al), 4.5% tantalum (Ta), 0.03% carbon (C), 0.03% zirconium (Zr), 0.1% hafnium (Hf), 0.5% silicon (Si), 0.1% lanthanum (La), and 0.1% yttrium (Y).

8. The alloy according to any one of claims 1, 2 or 3, comprising: 6.0% to 9.0% cobalt (Co), 7.5% to 9.0% iron (Fe), 14.5% to 15.5% chromium (Cr), 0.5% to 1.0% molybdenum (Mo), 2.0% to 3.0% tungsten (W), 4.8% to 5.2% aluminum (Al), 3.5% to 5.5% tantalum (Ta), 0.01% to 0.05% carbon (C), 0.01% to 0.05% zirconium (Zr), 0.05% to 0.15% hafnium (Hf), 0.3% to 0.7% silicon (Si), 0.03% to 0.13% lanthanum (La), and 0.03% to 0.13% yttrium (Y).

9. The alloy of any one of claims 1, 2, 3 or 8, comprising: 8.0% cobalt (Co), 8.0% iron (Fe), 15.0% chromium (Cr), 0.8% molybdenum (Mo), 2.5% tungsten (W), 5.0% aluminum (Al), 4.5% tantalum (Ta), 0.03% carbon (C), 0.03% zirconium (Zr), 0.1% hafnium (Hf), 0.5% silicon (Si), 0.1% lanthanum (La), and 0.1% yttrium (Y).

10. The alloy according to any one of claims 1, 2 and 3, comprising (in wt%): 6.0% to 9.0% cobalt (Co), 7.5% to 9.0% iron (Fe), 14.5% to 15.5% chromium (Cr), 0.6% to 1.0% molybdenum (Mo), 2.0% to 3.0% tungsten (W), 4.8% to 5.2% aluminum (Al), 3.5% to 5.5% tantalum (Ta), 0.01% to 0.05% carbon (C), 0.01% to 0.05% zirconium (Zr), 0.005% to 0.015% boron (B), 0.05% to 0.15% hafnium (Hf), 0.3% to 0.7% silicon (Si), 0.03% to 0.13% lanthanum (La), 0.03% to 0.13% yttrium (Y).

11. The alloy of claim 10, comprising (in wt%): 8.0% cobalt (Co), 8.0% iron (Fe), 15.0% chromium (Cr), 0.8% molybdenum (Mo), 2.5% tungsten (W), 5.0% aluminum (Al), 4.5% tantalum (Ta), 0.03% carbon (C), 0.03% zirconium (Zr), 0.01% boron (B), 0.1% hafnium (Hf), 0.5% silicon (Si), 0.1% lanthanum (La), 0.1% yttrium (Y).

12. The alloy according to any one of claims 1, 2 and 3, comprising (in wt%): 6.0% to 9.0% cobalt (Co), 7.5% to 9.0% iron (Fe), 14.5% to 15.5% chromium (Cr), 0.6% to 1.0% molybdenum (Mo), 2.0% to 3.0% tungsten (W), 4.65% to 5.05% aluminum (Al), 3.5% to 5.5% tantalum (Ta), 0.01% to 0.05% carbon (C), 0.01% to 0.05% zirconium (Zr), 0.35% to 0.65% hafnium (Hf), 0.3% to 0.7% silicon (Si), 0.03% to 0.13% lanthanum (La), 0.03% to 0.13% yttrium (Y).

13. The alloy of claim 12, comprising (in wt %): 8.0% cobalt (Co), 8.0% iron (Fe), 15.0% chromium (Cr), 0.8% molybdenum (Mo), 2.5% tungsten (W), 4.85% aluminum (Al), 4.5% tantalum (Ta), 0.03% carbon (C), 0.03% zirconium (Zr), 0.5% hafnium (Hf), 0.5% silicon (Si), 0.1% lanthanum (La), 0.1% yttrium (Y).

14. A component, in particular for a gas turbine, comprising an alloy according to any one of claims 1 to 13.

15. The component of claim 14, being a blade, vane, heat shield or disk.

16. The component according to claim 14 or 15, having a single crystal (SX) or columnar (DS) microstructure.

17. A method for producing a component, in particular a component according to claim 14, 15 or 16, wherein: An alloy according to any one of claims 1 to 13 is used.

18. The method according to claim 17, wherein The component is cast, in particular using a temperature gradient.

19. The method according to claim 17, wherein Using additive buildup, in particular using cladding or powder bed methods.

20. The method according to claim 17 or 19, for repairing a component, wherein: A substrate is repaired using the alloy according to any one of claims 1 to 13, said substrate in particular having an SX or DS structure, and wherein in particular an SX or DS structure is also accumulated.

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