GB2626730A - Oxidation resistant Nickel (Ni) base superalloy, powder, components and methods - Google Patents

Abstract

A nickel-based alloy which comprises (by weight): 6.0-10.0 % cobalt, 6.0-10.0 % iron, 12.0-16.0 % chromium, 4.2-5.4 % aluminium, 4.0-8.0 % tantalum, 0.05-1.5 % hafnium, 0.005-0.1 % silicon, 0.01-0.3 % total of rare earths, actinides and/or lanthanides, 0.01-0.3 % carbon, 0.005-0.3 % zirconium, optionally 0.5-6.0 % molybdenum, optionally 0.5-6.0 % tungsten, optionally 0.3-6.0 % rhenium, optionally 0.0015-0.3 % boron, with the balance being nickel (Ni). The alloy can be used to make powder which can be combined with a binder for binder jet printing or combined with abrasive to form seals. It can be used for making components by additive manufacturing or by casting.

Description

Oxidation resistant Nickel (Ni) base superallov, powderCOM.-ponents and methods The esent in-,ition relates to a nlskelebase gamma prim strengthened superalloy, a powder, combonents and methods to produce components. 1.0

fur relates to its use for Liquid Metal Deposition (IND) of components such as; but not restricted to, blades, vanes, heat shields, sealings and combustor parts in turbines or gas turbines. it further relates to its use for powder bed.

processes such as, but not restricted to, Laser Powder Bed. Fusion (LPEF) of components such as, but not restricted to, blades, vanes, heat shields, sealings and combustor parts in turbines or gas turbines. It further relates to its use for casting of components such as, but not restricted. to, vanes, heat shields, sealings and combustor parts in turbines or as turbines. !t furtiher reiates to Its use for hot components which need tc resist metal dust-bcg.

Blade alloys are. es sen.iab for critical components in aero 25 and. land-based gas turbines; but are used also la other applications.

The di fference. between blade alloys depend on the level of knowledge and production. technology available at the time they were developed, and, on different relative emphasis on properties such as hot corrosion resistance, oxidation resistance, weldability, phase stability and creep strength-AM proccssability is linked to weldability since they are to a large extent welding processes.

Blade alloys are used in mwmocrystailiee (SF), directionally solidified, columnar (DS) or eqpiaxed (CC) microstructure, Each draAn is a crystal mainly conbisiing of a matrix of the gamma phase, which is essentialty Nickel (Ni) with elements like Cobalt (Co), Iron (Fe), ChroHum (Cr), Molybdenum (Mb), Tungsten (W) and/or Rhenium. (1..e.') in solid. solution, and par-ticles of the gamma prime phase, which is essentially Nik3A1 with elements like Ti, Ta and. Nb in scwid. solution. Each grain is a two-chase crystal in which the gamma matrix and the gamma prime particles share the same crystal orientation and the boundaries between the mairii, and. the particles are coherent. Crain. boundaries, if present, are usually decorated by carbides and/or borides which provide cohesive strength. Zirconium (Zr) also contributes to grain boundary cohesion.

Creep strength is provided by elements like Molybdenm Tungsten (.1.:4) and/or Rhenium (Re) which. provide solution strengthening of ifv2. gamma matrix, and, Titanium (Tl), Tantalum (Ta) and/or Niobium (Columbium, Nb), which provide solution. strengtheining of the gamma prime particles. Aluminum (Al) provides creep strength as it increases the amount of gamma prime particles, and, as the presence of gamma prime particles concentrates the levels of Molybdenum (Ma), Tungsten (W) and/or Rhenium (Re) in the matrix. The creep resistance is enhanced by a coarse-grained structure as obtained by polycrystalline casting or directionally solidifi-cation casting, or, even more efficiently, the absence of grain boundaries as. in monocrystailine casting.

AM processes such as LM.11) or LPBE tend to result in a fine-grained structure. The resulting reduction in creep strength

FS

can, depending on the component to be designed, be compensated for by the design possibilities provided by AM processes, Blade alloys get t.-fr.-2ir protection against oxidation and con -iosion through formation. of a protective, i.e., colltimious and. adherent, Cr y03 layer and/or a protective, 1.e., c(untinuous and adherent, Aine-layer, in the oxide scale.

It is generally accepted that protective Cr2C., formation reqfllre at. least 12,0wt% Chromium (Cr). Cr203 layers, if the can be formed, typically stay long term T.irctective up to temperatures in the order of 1173K in the flowing hot gas environment in the gas turbine hot path.

Continuous P.120:: lavers, if they can be formed, typically. only form_ above temperatures in the order. -F 1123K. As the temperature decrease the Aluminum (-A1) 'sctivity also decreases and eventually protective Alf,a:j can. no longer form.

Corrosive agents such as the alkali. salts occurring in gas turbines are generally taken to be especially active in the 973K to 1123K range where they can occur as molten deposits, Since this is a tempature range in which protect, Cr20., can form if fl-,e Chromlum (Cr) content is at least 12.0wt%, the general rule of thumb is that resistance to hot corrosion, which is the label used for corrosion due to alkali salts, is compromised if the Chromium ((17r) content is below 12,0wt%. Molybdenum (Mo) in the alloy will be present In the spinel's above the protective layer and can react with and exacerbate corrosive deposits. Hence to much Molybdenum (Yin) is detrimental to the hot corrosion resistance.

it is known hot corrosion r of the 1 romium. (Cr) aero alloys CKSX.-.4 and mrcsx. is significantly nferior to that of the alloys 111792 and TNII3SLC. which have more than 12.0wt% Chromium (Cr) at. 1123K.

D. Goldschmidt teaches In "Single-Crystal:Modest' In Proc. from. Materials for Advanced. Power Engineering 1994, Part T, p.661-674 that the hot corrosion resistance of the blade al--by SC16 with 16.0wt.% Chromium (Cr) and 3.0wt I Molybdenum.

(Mo) Is gnificantly inferior to that of the blade alloy.

TN738AC with 16.0wt% Chromium (Cr) and 1.8wt% Molybdenum (1,4o), It has recently been shown that hot corrosion can be an issue also as temperatures. down to at least 773K.

It is known that the hot norrosion stress corrosion cracking resistance of the New ICT alloys SCAL153K and STAL125Cci having > 12.0wt% Chromium (Cr:) is significantly superior to the low Chromium (Cr) Aero alloys cJv5247CC and CMSX.-4.

If the amount of alloy elements is too high, unwanted phases CUP) such as Sigma and Laves phases will form in service.

Therefore, an increased of alloy elements other than ahromium (Cr) must be accompanted by a reduction in Chromium (Cr) if too IT,,CM UP formation is to be avoided, implying a conflict between corrosion resistance and other properties. One particular effect of UP precipitation is a reduction to creep strength, Another effect is embrittlement of the blade alloy. Another effect is reduction of oxidation and corrosion resistance if Chromium(Cr) is tied up in Chromium (Cr) rich UP, In the context of high firing temperature pas tuxbines, it is ge.neraliv accepted that high oxidation. resistance implies the abill 5Y to form protective A120.., layer,as needed towithhtand metal temperatures on or exceeding the 1273K level. Further:-more, the oxide scale spallation caused by the always present. sulfur cflhrami_natton must be suppressed. Furthermore, there must be a margin auainst loss of the ability to reform protective alumina since each reformation implies a loss of Aluminum (Al), Furthermore, the use of alloy elements such as Titanium (Ti) will cause contamination. of the Al2Ch layer as Titanium (Ti) partially substitutes for Aluminum (sql) in. said layer, rendering the layer less protective. Furthermore, it is beneficial to enable fast selective oxidation of Al--CA, as this will reduce the thickness of the oxide scale and make it less prone to spallatlon The ability for formation of protective A1202, and the margin against loss of Aluminum. (Al) via scale 5-palliation, is a complex function of the Aluminum. (Al) content and the combina-tion of other alloy elements which, acting in synergy, enhance or reduce this ability. In CAT.PHAT) terms this ability is associated with the predicted Aluminum (Al) activity. In the context of blade alloys CALTHAD means use of thermodynamic software such as Thermocalc for prediction of entities such as partitHoniug of alloy elements between gamma and gamma prime.; iiquidus, solidus and gamma prime solvus temperatures; gamma prime content; risk for precipitation of U2; Aluminum. (Al) activity. An increased Aluminum (Al) activity also implies faster selective oxidation o5 protective The following observations on alloy element additions for improved oxidation resistance can be found in the literature: C.A. Barrett: Statls of Frievated Temperature Gravimetric Cyclic Oxid.atb on Data of 36 Ni-and. Cobalt (Co)-base Superallovs based on an Oxidation Attack Parameter NASA. TM 105934 teaches that the ability to form protective AM.C..

is provided. by Aluminum (A1), enhanced by Chromium (Cr) and. Tantalum (Ta), somewraL reduced by Molybdenum (ME) and Tungsten (W), and significantly reduced. by Tltanium (Ti) and Niobium. (Nb). This was based on a large correlation study on commercial as well as exmerimental blade alloys. This implies that less Aluminum (Al) is needed no form a protective A1203 laver if the levels of Chromium. (Cr) and. Tantalum. (Ta) are increased, or, the levels of Titanium (Ti) and Niobium (Mb) are reduced.

Sarioqin, et al. : The Control of Sulfur Content in Nick- el-Base Single Crystal Superallovs and its Effect on. Cyclic Oxidation Resistance Proceedings 'Superalloys 1996' teaches that. the scale adherence is severely reduced by tramp elements such as Sulfur (S), but, tliat this effect can be neu-tralized by a combination of clean casting and addition of small, measu d levels of reactive elements (RE). Withal.: RE additions, it is necessary to be well below-lppm Sulfur (5) to avoid a detrimental effect on the scale adherence.

B.R. Pirt at a]: Effect. of Cycle Frequency on High.- Temperature Oxidation Behavior of Alumina-and ChromiaForming Alloys Oxidation of Metals, 50 (1/2), 3-101 (2002) underlines the importance of 5, and further teaches the bene-fbi ci RE effects when small levels of Hafnium LH and the rare earth Yttrium (Y) are combined.

Caron et al.: Improvement of the Cyclic Oxidation Behaviour of Uncoated Nickel Based Single Crystal Superallovs Materials Proceedings 'Materials for Advanced Power Engineering 1994' teaches the beneficial RE effects when small levels of Hafnium (BIC and Silicon (Si) are combined.

B.A.. Pint et al. : The use of Two Reactive Elements to Opti-mdze Oxidation Performance of Alumina-Forming Alloys Materials at High Temperature 20(3) 375-386, 2003 teaches that signitBcant RE effects can be obtained when a. multiple RE recipe is i.used, one example being the excellent cyclic oxidation sistance seen. in bebts on Haynes-214 which contained small levels of Zirconigm (Zr), Silicon (Si) and Yttrium (1) It is generally accepted that the risk for hot tearing during P,B1 processes such as LMD or LP2F, and strain age cracking duirino a subsequent solubiohing, increase with increasing nominal gamma prime content., taken as the egullibrHum content at 1123KCiarbon (Cif and the gamma prime solvus temperature. Our in-house experience is that 111939, having a gamma prime content of about 35mol and a Solvus of about 1353K can be readily processed while I11738LC, having a nominal gamma primR content of 44moLP and a solvus of about 1433K, can be handled lf with more qualltloatHn efforts and stricter requirements on the levels of grain boundary elements like Boron (R) and Zirconium (Zr) as well as on the allowable level of Silicon. (Si), Higher gamma prime contents tend to require even more efforts, including more el=Thorate and costly 2414 production.

processes and even more qualification efforts. It is thus useful to keep the gamma prime content on at most the 111738.L.fl level, and preferably on the 1N939 level.

Most blade alloys can be characterized as Classical industrial Gas Turbine (IGT) alloys, Aero alloys or New 1ST alloys.

These alloys have > 12.0wt% Chromium (Cr) for formation of protective Cr.j.)3, see figure. The classical PflT blade alloys do not have ability to form protecni although SC/u425 4.0wtil Aluminum (Al) supported by 16.0wtii Chromi-um. (Cr) is border. line. In house oxidation testing. at 1273K has shown that 5CA425 will form a continuous layer of Al8CA on most hut unfortunately not all of its surface. Its Alumi -nbm (Al) activity at 1273K is 3.1e-6 based on owl Lb TTN18 as data base. The C8assjcal TOT alloys do not fulfil our object:hie since they are not able to form protective I 0 The class of Aero alloys include the 01-1247CC, used for CC and DS casting, and CMSX-4 and Rene N5, used for SX casting, see Table. Their hot corrosion resistance is poor due to their low Chromium (Cr) levsls. Most of them can form protective 15AeitC18 thanks to high levels of Aluminum (Al) and la, and, despite low levels of Chromium (Cr), The Aero alloys do not fulfil our objective since their corrosion resistance is poor, Furthermore, their high gamma prime contents, tycdoall in the 60m0I% to 70mb:185 range, imply that they are difficult to process by AM processes such as LMD or The class of New ICJ' alloys include th-TX alloy STAL15SX, the CC alloys =AL125CC1 and SMI(15CC, and the LiMB alloy STAL13SiLaL see Table. These alloys have ificient Chromium (Cr) for formation of protective Cr-808i at low and hitermedi-ate temperatures, typically up to about 1173K. Furthermore, they form protective A1/38 at high temperature, typically above about 1123H, thanks to moderate to high levels of Alu.-minum (Al) supported by significant revels of Chromium (Cr) and Tantalum (Ta).

It is therefore aim of the invention to overcome these problems The problem is solved by an alloy, a. powder, components and methods according to the independent claims.

In the dependent claims further advantages are listed which 5 can. he arbitrarily combined with each other to yield further advantages, An objective of this invention to provide a blend of good hot cortosion resistance, excellent oxidation resistance, good processahility for AM processes such as EMD and 0113E., nigh phase slabliity, and a good creep resistance by AM standards. Alternatively, it is an obi ective of this invention to provide a blend of high hot corrosion resistance, excellent oxidation. resistance, high AM processahility, high phase 5tabil-ity, and a moderate creep resistance by h.M. standards. Within the present inve:ntion creep strength can accordingly to some extent be traded for increased hot corrosion resistance.

These blends are useful for repair of oxidation damage components such as, but not limited to, blades, vanes, heat shields, seaiings and combustor parts in turbines or in gas turbines, usin,.j AM processes such as, but not restricted to, LMD and..r.TBF. They are furthermore useful for cladding of components such as, but not restricted to, blades, vanes, heat shields, seal logs and combustor parts nrr turbines or in gas turbines, using AM processes such as, but not restricted to, LED or 02011 to preempt oxidation damage in service. They are furthermore useful for fabrication, of highly oxidation. resistant components such as, but not restricted to, vanes, heat shields, sea-lines and combustor parts in turbines or in gas turbines, using AM processes such as, but not restricted to, TED or IPPF. They are furthermore useful for precision casting of compone:nts such as, but not restricted to, vanes, heat shields, sealings and combustor parts in turbines or in gas turbines. They are furthermore useful when corrosive fuels are used, one example being corrosive biofaels. They are furthermore useful to manage corrosive agents such as sea salt in the inlet air. They are furthermore useful for alter-native applications such as managing of hot flowing hydrocarbons which provide a corrosive a:I-Ad carbonising environment with a low partial pressure of oxygen (02).

As one possible area of application: Efficient internal cool ing of edge iod tips on not bace gas turbine parts is difficulj to achieve, hence a significant amount of the cooming air used in a cats turbine is spent on dilution air which is mixed with the hot gas stream in the vicinity of tips and edges to locally reduce the temperature of said hot as stream in order to avoid too much oxidation damage. Any improvement in metal temperature tolerance can therefore be translated into reduced dilution air usage resulting in improved gas turbine thermal efficjency and consegueutly in red=ed. CO? emissions.

The class of Classical IGT alloys include the polycrystalline 1N939, TN738Lnarben (C) and TN792 (see table) 1N93 IN738LC IN792 515CC 5125CC E125 E15rvi E15W E14 CM247C 9 1 0

BB BB

Cr 22.0 16.0 12.5 15.0 123 12.5 15.0 15.0 14.0 8.0 Fe 8.0 8.0 8.0 6.0 Co 19.0 8.5 9.0 5.0 5.0 8.0 8.0 8.0 9.5 Mo 1;8 1.8 1;0 1.5 1..0 1.5 1.0 0.6 2.0 2;6 4.0 3;7 3.5 3.7 2.5 3.7 2.0 9.5 Al 1.9 3.5 3.4 5.1 5.5 5.1 4.5 43 6.5 5.6 Ti 3.7 3.5 4.0 0.7 Ta 1;4 1.3 4.0 8.0 8.0 6.5 5.0 5.0 3.2 3.2 Nb 0.9 0.9 Hf 0.5 0.1 0.5 0.1 0.1 0.1 1.5 1.4 0.15 0.07 0.07 0.07 0.07 0.05 0.05 0.05 0.05 0.07 Zr 0.1 0.03 0.02.015.015 0.01 0.01 0.01 0.01 0.01 0.01.015.015.015.015 0.01 0.01 0.01 0.01 0.01 Si 0.01 0.01 0.01 0.01 0.01 0.02 Other 0.05Y 0.05Y 0.05Y 0.05Y [MON1 35 44 52 52 59 44 32 34 48 65 Al act. 42 4.4 8.4 7.6 8.0 7.6 n.a.

Table: _Element.drlitons in 114.Tt%J. STALd5C2 is abbreviated as Si 520, Edgei2D) abbreviated as 2125 etc. Aluminum activity values are relative values at 1273K, v" is the equiMibrium rr, content at 1123K.

S1A1125CC1 is taken as the norm for good hot corrosion resistance thanks to having 12.5wt% Chromium (Cr) and < 2.0wt5 Mo I ybd e num (Mc smAT15.85 is taker as the norm for high hot corrosion resistance thanks to having 15.0wt% Chromium (Cr) and < 2,9wt% Molybdenum (Mo) CM247CC, as fabricated by a low sulfur process with <5ppm Sulfur (5), is taken as the norm for high oxidation resistance thanks to its ability to form protective alumina ana efficiently suppress the oxide spallaUo5 caused by sin-fur. It is a commonly chosen blade alloy when a high oxida-tion resistance is needed. Excellent oxidation resistance is taken as the ability of an alloy to be essentially unharmed in severe cyclic oxidation tests in which CM247CC is essentially destroyed.

The norm for hiah AM processability is taken as a combination of high 'MD and LPHE processalMlity. The norm for High. LMD processailitv is takan as the ability to perform crack free LMD using weloi seams in the order of 0.5mm to lam in wHdth and height, with no subsequmnt strain age cracking, for a range of high strength blade alloy substrates. The norm for iPBF processacili 7 i,s taken as the ability to print the dog hone and cruciform geometries, two established. crack provocation tests, crack free and wlth re: sLbsequent strain age cracking.

High phase s Labi I. it.y is taken as phase stability, as calculated using ThermoCalc with TTNi8 as thermodyaTHfl database, on the same level as the New IndusLtiei Gas Turbine (IGI) alloys STA-LISSY_ and. STAL125C.Ci, which show no precipitation of unwanted phases (UP), such as haves or Sigma, in creep tests with rupture times exceeding 10kh in the 923K to 1123K range and do not form J? in service.

Moderate creep resisuahce is taken as creep resistance on the revel of fine grained 1M939 as e.g., obtained by LPBF or IN939Good creep resistance is taken as creep resistance on the level of fine grained IN738LC as e.g., obtained by LPE,F of IN738LC, In the present invention, a judicious combination of Iron (Fe) and Cobalt is used to improve the oxidation fl77-sistaoce and AM processdblitv significantly relative to STAI.15CC., When iron (Fe) and Cobalt (Co) are added, the partitiondnq Of Aluminum (Al) is altered and, as a result, the gamma prime content is reduced such that:he 73,M processability is increased. When Aluminum (Al) is forced into the gamma prime matrix, the oxidation resistance is increased.

The alloy COMpriSAS between 6.0wt% Cnbalt, (Co), between 6.0wt% and 10.0wt% Iron (Fe), between 12.0wt% and 16.0wft Chromium (Cr), between 4.2wt,?; and 5.4wt% Aluminum (Al), between. 4.0wt% and 0.0wthis Tantalum (Tha), at least 0.01wt% Carbon. (C), at. least 0.005wt IZI,rconium (Z,r), between 0.05wt% and 1.5wt% Hafnium (Hf), between 0.005wt?. and 0.1wtc% Silicon (Si), between. 0.01wt%, especially 0.02wt%, and 0.3wt% of the sum of rare earths such. as Scandium (So) Yttrium (Z), the actinides and the lanthanides, optionally at least 0.5wt% Molybdenum (-.1.4.(p) or at least 0.5wt% Tug.sten Cl) or at least 0.3wt,% Rhenium (Re) or at least 0.0013,wt I -Boron (3)..

Especially betwuen 3.Owt7i.. and 6.0wt. of Molybdenum (WY) Tungsten (W) and/or Rhenium (Re), at most 2.0wt% Molybdenum (Mo) are comprised by this alloy.

Further advantages are yieldpd with 0.02wt% and 0,3wt% of Carbon (C) + Zirconium (Zr) Boron (E).

The function of the following alloying elements are valid.

separately for all inventive alloys: Chromium (Cr) is used at at least 12.0wt% to enable formation of protective Crga, and thus enable good hot corrosion resistance. The Chromium (Cr:) content is limited to 16.0wt% to avoid the risk for too much UP precipitation. Chromium (Cr) also contributes to the T\luminum (A.l) acXivity.

Optionally. Molybdenum (M.o) is used at at least C -5w1:i to provide strength to the gamma matrix hut is preferably limited 25 to at most.3,0wt% to avoid a detrimental effect on the hot corrosion resistance.

Optionally. Tungsten XI tensed at at least 0.5wt%, more preferably at at least 2.0wtS to provide strength to the gam-30 ma matrix but is preferably limited to at most 4.5wt% to avoid the risk for too much UT.

Rheniun (TiRo) can be used preferaoly up to 1.0wf%. 11-\,t higher levels its effect on the phase stabili ty rr.c:.qr.Lt be too dotrimental.

Aluminum (Al) is used at at least 4,2wt? )1e a high Aluminum activity. Tho upper imi t js set at 5.4wt. I to avoid. too much gamma. prime formation and an associated loss or AM processability.

Tantalum (Ta) is used at at.east 4,0wis% to provide strength and contribute to the AluniniAm activity. The upper limit is set to 8.0wt% to avoid too much_ OP formation.

Hafnium. (Hf) is. usea at a small measured value, of at least 0.05wt% to provide a Sulfur gettering effect, but can be set to a. higher level to e.g., provide an increased resistance to rumpling in an applied aluminide or platinum aluminide coating. The upper limit is set at 1.5wth to avoid the risk for too mach UP formation, Carbon (C) ±5 preferably included at at least 0.01.int% to pro-. vide grain bpundary strengthening. Th2 upper limit is set preferably at 0.15wt. as higher levels might result in a too brittle behavior_ Boron (2) is included at at least 0,001.5wt% to provide grain boundary strengthening. The upper limit is set preferably to 0,03wt% since hi r levels could reduce the AM procossabil-ity too much.

Zirconium (Zr) is included at at least 0.005wt5 to provide grain. boundary strengthening and to act as a. Sulfur (5) scav-enger. The upper limit is set preferably to 0.1wt% as in I15939 since higher levels could reduce the AM processability too mach.

The 59m of Scandium (cic), Yttrium (3:), the Actinides and the Lanthanides is included at at least 0.02wt% for sulfur scavengi. ng, The upper ihmHt Is set to 0.3 wt% since higher levels fright resulL in Loo much rare earth oxide inclusions, which _Tight result in a brittle behavior.

Silicon (Si) is included, at at least 0.005wt1 to provide a beneficial9 catalytic effect on the formation. of protective A120i. The upper limit is set at G.iwt% since higher levels might result in embrittlement of the grain boundaries.

The blade alloy according. to the invention is preferably processed with a clean production process. To guarantee best re-. sults, the blade alloy should contain less than 5ppr. Sulfur, preferabdy less than ippm Sulfur (S).

The inventive idea is exemplified below: STALd5CC, see Tae ble, is a high strength, highly oxidation resistant, highly hot corrosion resistant Oiade alloy. IliowPver, with 52 molt gamma prime it. does not meet the AN processabilitv objective. Furthermore, the objective is an extreme rather than a high oxidation resistance.

In one embodiment of the present invention called Edge125, see Table, Cobalt (Co) is increased, and Iron (Fe) introduced relative to sTmascc.

This alters the partitioning of Aluminum (Al) forcing more Aluminum (Al) into the gamma matrix. Inc gamma prime content is thus reduced. Tantalum (Ta) is then subseTiently reduced to provide about the same amount Of Tantalum strengthening per mo...N gamma prime as in ST.Alii5CC and this further reduces the gamma prime content somewhat. The Chxomium (Cr) content is then reduced to maintain the good phase stability of STAT.:MCC despite more Aluminum. (Al), Iron. (Fe) and Cobalt (Co) in the gamma matrix. The result is a gamma prime, content 5 of 44mo1 as predicted with ThermoCale using TTNli8 as data base. This is the same level as in TN736LO, suggesting a. sl-mliar AM nrocessatHlity. The Chromium content in Edue125 is the same as in I51792 and Sr2A1.125CC1, and the Molybdenum (",,R content is low at 1.0wt22, suggesting a good hot corrosion. re -sistance, Edge125 contains 1,0wtc.,-; Molybdenum, 3. 7wtl Tungsten and 6.5wt% Tantalum as strengthening elements, Thls is significantly higher than in Edge14. The RE recipe in Edge125 is extended relative to STAL1i5Ce. by the addition of a small amount of Yttrium (11). b

In one embodiment called Edgel5W, see Table, the hluminum. (Al) content is reduced relative to Edge125 and the gamma prime content is thus further reduced.

Tantalum (Ta, is then further reduced to provide about the same amount of Tantalum. (Ts) strengthening per mail gamma prime as in sr:TAT:15a: and Edge125. Chromium (Cr) can nom. be HnPreased. to 15.0wt% while the phase stability seen in Edge 125 and STAL.15CC is kept, The gamma prime level is reduced to 34mo11.1, as predicted. by ThermoCalc with TTNiS as da- ta base. This is similar to 151939. The hot corrosion re-sistance is higher than in Edge125 thanks to a higher Chromium (Cr) content. Edgel5W contains 1.0wt% Molybdenum, 3.7wt% Tungsten and 5.0wt% Tantalum (5a). This is a higher level of strengthening elements, especially in the gamma matrix, than in Edge.14.

Other embodiments can be derived by those skilled in the ail, to e,g., enable better matching to specific substrates and/or coatings, and, to further enhance the Sulfur (5) gettering.

In Edgel5No, see Table, Tungsten (1(N) is partially replaced. by Molybdenum (.M.o) retat'..v.e to Fdgel',W. Similarly, Rhenium (re.) can be introduced at the expense of Molybdenum (Mc) and/or Tungsten (W) to get a better matching. to Rhenium. containing blade alloys.

The addition of Yttrium (Y) can be replaced by a combinotHon of Yttrium no and LanLhanum (La) to further. improve the RE recipe, A farther possibility is the use of mixed metal. This 1.0 is a mix of rare earths, usually dominated by a combination. of Lanthanum (La.), YLL.rHim flfl and Cerium. (Cs), and the use of mixed metal can be beneficial from a cost as well as a performance point of view.

Edge125, Edge151/2( and Edgel5Mo nave predicted Aluminum Activities of 2.4e. -S, 8.0e-8 and 7.6e-8 respectively at 1273K. These are almost twice those in e.g., STAL15CC. and STAL.125CC1, see Table, strongly suggesting an extreme oxidation resistance.

EdgeN(.(.-) has been successfully applied by INT) onto C.N.24755 (DS and CC cast), STAL125CC1 and 114792 by LMD with no cracking at the interphase, or, within the applied EdgeiSMb. Furthermore, no cracking was seen during the subsequent sal-tioning, done at tho solutioning temperatures for the substrates. This was achieved within a wide process window for weld seams of about 0.5 by 0.5rnm. Based on in-house experience this implies at least 11)939 level LMD processabiltty, Crack provocation geometries have furthermore been printed by LPBF using Edgel5Mo, and, no cracking was seen during the printing, or, during a subsequent solutioning at 1523K. The complete absence of cidiie for those geometries has not even. been seen for I,PBE of 1M939 despite lengthy process parameter optimization work.

Specimen oct51 st i.ricT of Edgel5Mo applied. an C11247CC via. LMD have been evaluated in cyclic oxidation tests. Since it was difficult to find test conditions which resulted in damage to Edgei5Mo, the test. parameters were made increasingly severe until a cyclic oxidation. test with 1000 cycles with a hold time of lh at 1523K per cycle was evehtually used. Higher temperatures could not be used as this might have caused in.-cipient meitinq in the substrate which is solutioned at about this temperature. In this test the Edgel5Mo material was stIl.1 essentially unharmed while several mm was lost in those areas of the CM24700 substrate which were not protected by the Edgei5Mo layer, or, by contact with the ceramic specimen holder. It should be added that the slightly uneven surface on Edgel5Mo is not caused by oxidation, it is slightly uneven since only polishing was done after the LMD application prior to the testing. CM247CC was used for the demonstration of the edge alloy concept in it is one of the most widely. used.

polycrystalline alloys when a high oxidation. resistance is 20 required_ It should be irentciotted. that Edgel4 has also been applied by. LMD on CM247CE1, anci such specimen have been evaluated with the sa= very severe test conditions as the CM247C(3./Ed '5Mo specimen and with almost identical results. Tn. the CM247GC/Edge.14 case this can be seen as natural given the high Aluminum content of 6.5wt% supported by 14 Owti Chromium. Edgel5Mb does however have a moderate Aluminum (Al) con-tent of 4.5wt%, but its Aluminum (Al) ac Livi is remarkably enough on the same level as that of Edge14 thanks to the combination of S. OutS Cobalt (Co) and 0.0wt% iron (Ye), and it did turn out that the Aluminum (Al) activity really is a trustworthy marker for oxidation resistance. A similar Alumi- num (Al) activity gave similar test results k'n,-the rPac-1.9 Live element recipe was also the same and. the powder was procured from the same supplier. with similar quality in terms of contaminants).

It should also be mentioned. that the omission of an Aluminum (Al) activity for 51124700 In Table Is based on the fact. ..".hal the data base TTNi8 is known to work less than well for CM247CC.

It should also be mentioned. that the oxidation. life of ap-plied. Al forming forming coatings such as aluminIdes benefit from having this edge alloy as a substrate below. The reason is that a major mode of degradation of such coatings is the loss of Aluminum from said coatings through di ft into the substrate, hence, if the Aluminum activity of the substrate is increased this loss of Aluminum (Al) via ddffosion is retarded. It should also be mentioned that aluminides and platinum aluminides can. suffer from spallation due to rumping but that this can be mitigated by having Hafnium in the sub-strafe as this will diffuse into the coating and reduce the rumpThng.

In addition. to the use of this edge alloy for local augmentation of the oxidation resistance and coating compatibility of compohe:nts cast or additively manufactred in other blade alloys, it can also be used for additive manufacturing or casting of entire components if these are at most moderately creep loaded_ This includes, but is not restricted to, sealing stractures, heat shields, moderately creep loaded. vanes and combustor parts in gas turbines.

In one embodiment called Edgel5 Tungsten ffifl, Alominom. (Al) is reduced relative to Edge125 an the gamma rime content. is thus further reduced.

Tantalum (Tai I a then further reduced to provide about the same ambunt of Tantalum. (Ta) strengthening per moil gamma prime. Chromium (Cr) can be increased to 15.0wt% while the phase stability of STALI5C.Cls kept. in Eidgel5W-the gamma prime level is reduced to about the same level as in 1N939 which is readily processed by T.M.19 and LTE7. The overall, level of strengthening of 7dgeT5W is similar to that of TN939 even if the balance between strengthening of the gamma and gamma prime is differemt. The gamma matrix in Edgel5W Ls trenqth-by lw.t% Molybdenum (1),10) 3. 7wti Tungsten. (W) while TN939 is only strengthened by 2.wt Tungsten (Tifl. The gamma prime particles in Edgel5W is strengthened by 5,0wt,i:i Tantalum (Ta), which is however still on the same level in strengthening. per molt gamma prime as in STAAJ5C.0 and at a higher level than In Rene N5, whi i.e 11)4939 is strengthened by 3.7wt% Tita-nium (Ti) 1.1nat% Tantalum (Ta) 1 0.9wteI Niobium. (Nb).

Edgel5W is thus comparable to 114939 from a strength and AM processability point of view, The Ai iminAm (Al) activities in. Edgel5W and Edgelo Molybdenum (Mc) are reduced relative to that of Edge125, but they are still significantly above that of birprLI5r. Carbon (C), see Figure.

Tt might seem surprising that Tron (Fe) an.d Molvbdenam (Mc)) can increase the Aluminum (Al) activity as much as suggested by CALPHAD. However, the oxidation resistance and the Aluminum (Al) activity are associated with the Aluminum (Al) con.tentinthe. gamma matrix, and this is comparatively. low. even.

in blade alloys capable of forming protective AlAlx since most of the Al normally partitions to the gamma prime particles. The relative increase in gamma matrix Aluminum (Al) content, as Cobalt. (Co) and Iron (Fe) force more Aluminum (Al) into said gamma matrix, is substantial.

E.dgel5Mo has been api.iiied by LMD on the Aerb alloy CM247DS, which. is the CM247GC. composition. cast by DC in order to produco specimen for oxidation testing. Since jti was djfficult to find test conditions which resulted in damage to the Edgel5Mo material, the test parameters were made increasingly severe LntL.L a. cyclic oxidation. test with 1.000 cycles with a hold time of lb per cycle was done at 15231C Higher temperatures could not be used as this would have caused incipient melting in the substrate which is solutioned at about this temberathe. In this test the Edgel5Mo material was still essentially unharmed while several mm was lost in those areas of the aP.1247C.0 substrate which were not protected by the Edge:15Mb layer ur by contact with the ceramic specimen hold- Edgel5M0 has furthermore been used to print the crack provo-cation geometries in the dog bone and crucifbrm specimen. Consistent crack free printing followed by no strain. age cracking in the subsequent selutioning was shown. This is net always seen even when 1M939 is pr.Inted and seldom seen wHen alloys with higher gamma prime contents are printed.

According to one embodiment of the invention the alloy include betweeh. -Owt% and 10.0wt% Cotxilt (Co), between 6.0wt% and 10. C.4!t.. Iron (Fe), between 12.0wt% and Owtl.

Chromium (Cr), between 3.0wt% and 6.0wL of Molybdenum (Mo) Tungsten (Zi) + (and/or) Rhenium (Re), at most 2.0wt Molybdenum (Mo), between 4.2wt% and 5.1wtS Al, between 4.0wtS and.

7.0wt Tantalum (Ta), between 0.05wt% and 0.15wt% of Carbon (C) + Zirconium (Zr) + Boron (2), at least 0.0.3wft Carbon at least. 0.01wt Zirconium (Zr), between C.05wt% and.

1.0wt% Hafnium (Hf), between 0.005wt% and 0.-Iwt Silicon (Si), and between 0. 03wt I, and 0. 3wtl of the sum of rare earths 3uch as Scandium (Sc) , Yttrium. (I), the act hnt and the lanthanides, Nickel (NCI.), especially the rest being Nickel (Ni) and unavoidable lmphr aLice.

AdditionE the alloy may include between 7 nd 9.0 wtk Cobalt (Co), between. 7.0wt% and 9.0wthl Tron ( e), between 12.0wt% and 13.Hwt% Chromium (Cr), between. 0.7wt and 1.3wt% Molybdenum (Mb), between 3.4wt))s and 4.0wt% Tungsten (W), between. 4,9wt% and 5.3wt,l') Aluminum, between 6.0wt% and 8.0wt% Tantalum (Ta), between C) -O4wt I and 0,08wt% Carbon (C.), be-tween. 0.005wt% and 0.015wt'l,), Zirconium. (Zr), between 0,005wta and 0.015wt% Boron (B), between 0,05wt% and 0.2wt% Hafnium (Hf), between 0.005wt% and 0.05wt% Silicon (Si), and between 0.03wt% and 0.2wt% of Yttrium (Y), Nickel (Ni), especially the rest being Nickel (Ni) and unavoidahae tmpuritHes.

In a preferred embodiment called Bdge125, the alloy may in-clude 8"Owtll Cobalt (Co), 8"Owt)))) iron (Fe), Chhomihm al)11-1" 1.0wtg Molybdenum (Mo), 3.7wthl: Tunmsten (W)" 5.1wt% Al, 6.5wt% Tanta l= (Ta), 0.05).,/tA Carbon (C), 0,01wt% Zirconi:ur.

(Zr), 0.1wt% Hafnium (Hf), 0.01wtcl S),licmn (5 1) and 0,05wt% IttrThr (Y), Nickel (Ni), cially the rest being Mickel (Ni) and unavoidable impurities.

Alternatively, the al Dv ma), inyiu e between 7. 0-aLl and 9.0wt% Cobalt (Co), between 7.0wt% and 9.Owt% iron (Fe), between 13.5wt% and 16.0wt% Chromium (Cr) , between 0.7wt% and 1.3wt% Molybdenum (Mc), between 3.4wt% and 4.0 wt% Tungsten. (W), between. 4,2wM% and 4.8wt% Aluminum (Al), between 4.0wt% :30 and 6.0wt% Tantalum (Pa), between 0,03wt% and 0.08wt% Carbon (C), between 0.005% and 0.015wt% ZlrcPnium, (Zr), :between 0.005wt% arid 0.ulbwt Boron between. 0.0.5wt% and 0.2wtY Hafntam. (Hf), between 0.005wt5 and 0,05w111 Silicon. (Si), and between 0.03wt,1 and 0.2w1% of Yttrtrum. (Y), Nickel (Ni), especially the rest being. Nickel (Ni) and unavoidable impurities.

In a preferred embodiment called Fdgel5W, the alloy may in-cludo 8.Cwt% Cobalt (Co), 8.0wt% iron (Fe), 15.0wt Chromium (Cr), 1.0wt% Molybdehum (Mo), 3.7wtS Tungsten (W), 4.5wt% Aluminum (Al), 5.0wt% Tantalum (Tal, 0.05wt% Carbon (c.), 0.elwt% Zirconium (Zr), 0.1wt% Hafnium (H)(1, 0.01wtJ) Silicon (Si) and 0,05wtk% Yttrium (1S), Nickel (Ni), especially the sc.,st being Nickel (Ni) and unavoidable impurities, Alternatively, the alloy may include between 7.0wtS and 9. Out): Cobalt (Co), between 7.0wt% and 9.0wt% Iron (Pe), 13.5wt% and 16.Owt% Chromium (Cr), between 1.2wt% and 1.6wt% Molybdenum (Mb), between 2.2wt% and. 2.817.(ti:): Tundste-1 (W)" be-tween 4.2wt% and 4.8wt7) Tiluminum (Al), betwpen 4.0w 1%-and 6.6wt% Tantalum (Ta), between 0.04wt% and 0.08wt% Carbon (C), be 0.005wtS and 0.015wt% Zirconium. (Zr), be 0.())05wt% and 0.015wt% Boron (B), between 0.05wt5 and 0.2wt% Hafnium. (df), between 0.005wt% and 0.05wt% Silicon. (Si), and between 0.03wt)): and 0.2wt% of Yttrium. (Y), Nickdi (1))(i), especially the rest being Nickel (Ni) and ulna-voidable impurities.

In a preferred embodiment called Edgel5W, the alloy may in-clude 8.0wt% Cobalt (Go), 8.0wt% Iron (Fe), 15.0wt% Chromium (Cr), 1.5wt, Molybdenum (Mo), 2.5wt% Tungsten (W), 4.5wt7: Al, 5.ewt% Tantalum (Ta), 0.05wt% Carbon (C), 0.01wt% Zirconium (Zr), 0.1 wt?; Hafnium (Hr.), 0,01wt% Silicon (Si) and 0..e5wtc); Yttrium (Y), Nickel (Ni) the rest being Nickel (Ni) and una-voidable impurities.

The blade alloy according to the invention is preferably processed with a clean production process. To guarantee best re-suits, tine blade alloy should contain less than 5ppm Sulfur(S), preferably less than ippm. Sulfur (S).

Alternatively, furthei embodiments can he designed to opti-mdze compatibility with specific coatings when the alloy is used as a base alloy. Alternatively, further embodiments can be designed. to optimize compatibility with specific base alloys and coatings when the alloy is used as filler alloy for cladding and weld. repair, In this case tlie inventive alloy is added to substrate, which has a different composition. 1.0

Claims (5)

1. Patent claims 1. Nickel base alloy, comprising. (in wt%i: 60% o 0.0% t 1 Cobalt (Cc), 6.011 to 10.0% Tran (Fe), 12.0% to 16.0% Chromium (Cr), 4.2% to 5.4% Aluminum (Al), 4.0% to 3,0% Tantalum. (Ta), especially 4.0% to 7.0% Ta, 0.051, to 1.5% Hafnlum 0.005% to 0.1% silicon (Si), 0.01% to 0.3%, especially 0.02% to 0,3%, of the sum of rare earths such as Scandium (Sc), Yttinum NI), the Act:Aikidos and/or the Lanthanides, wherein especially at least two rare earths are added, at least 0.01% Carbon. (C.) and especially maximum 0,15wt% Carbon (C)" at least 0.005% Zirconium (Zr) and especially maximum n lwtn zikm0mium (Zr), Nickel (Ni), especially remainder. Nickel (Ni), and unavoidable impurities, optionally at least 0.5% Molybdenum (Mc) and/or at least 0.5% Tungsten (N) and/or at least 0.3% Rhenium (Re) and/or at least 0.0015% Boron (R) and especially maximum 0,03wt% Boron (B).
2. 2. Alloy according to claim 1, comprising. (in wt 1) 3.0% to 6.0% of Molybdenum (.Yfo) and/or Tungsten (16) and/or Rhenium (Re), especially at most 2.0% Molybdenum. (-Mo) and/or especially at least 2.09 Tungsten Rfl.
3. 3. Alloy according to claim 1 or 2, comprising. (in wt,%): 0.02% to 0.3% of Carbon) and/or Zirconium (Zr) and/or Boron (B), 4. Alloy according to any of the claims 1, 2 or 3, comprising (in wt %).
4. 4 I; 7.0% to 9 fl% flob-lt (Co), 7.(3% to 9.0% Iron (Fe), 12.0% to 13.5% Chromium (Cr), 0.7% to 1.3% Molybdenum 1..Mo), 3.1% to 4.0% Tungsten (W), 1.9% to 5.3 Aluminum (Al), 6.0% to 8.0% Tantalum (Ta)" 0.04% to 0.08 Carbon (C), 0.005% to 0.015 Zirconium (Zr), 0.005% to 0.015% Boron (F), 0.05% to 0.2J':, 'Hafnium (Hf), 9.005% to 0.95% Silicon (Si), 0.03% to 0.9% of Yttrium (Y).
5. 5. .Alloy according to claim. 4, comprising (in wt.%): 8.0% Cobalt (Co), 3.0% Iron (Fe), 12.51 Chromium (Cr), 1.0% Molybdenum (Mo), 3.7% Tungsten (W), 5.1% Aluminum (Al) 6.5% Tantalum. (Ta), 0.05V.Carbon (C)" 0.01wt% Zirconium (Zr), 0.1wtB Hafnium (.Ff), (1(11 4-') Silicon (Si), 0.05wt% Yttrium 61), 5. Alloy according to any of the claims 2, 3, comprising (in wt%) 7.0% to 9.0% Cobalt (Go), 7.0% to 9.0% iron (Fe), 13.5% to 16.0% chrof)lum (Cr), to 1 20 flolybOennm 3.4% to 1.0% Tunusten (Nl" to 4.8% Aluminum (Al) 1.0% 1-fl 6j0: Tantalum (Ta), 0.03% to 0.08% Carbon (C), 0.005% to 0.015% Zirconium. (Zr), 0.0051: to 0.015% Boron (B), 0.05:1 to 0.2:1 Hafnium (Ht), 0.005% to 0.05% Silicon 0.03% to 0.2% of Yttrium (Y).7. Alloy according to claim comprising (in wt%): 8.03 Cobalt (Co), Trnn (7A), 15.0B Chromium (Cr), 1.0% Molybdenum (Mo), 3.7% Tungsten (W), Aluminum (Al) Tantalum (Ta), 0.058 Carbon. (C), 0.01% Zirconium. (Zr:) 0.18.. Hafnium (H5), 0.01% Silicon (Si), 0.05% Yttrium (Y.).8.Alloy according to Claim 6, comprising (in. wt%): 3.0% Cobalt. (Co), 1.0 8.0% iron (Fe), 15.08 Chromium (Cr), Molybdenum (Mo)" 2.5% Tungsten (W), 4.5% Aluminum (Al), 11u 5.08: Tantalum (Ta), 0.05% Carton. (C), 0.01% Zironium (Zr), 0.1% Hafium (Hf), 0.01% Silicon (Si), 0.05% Yttrium (Y).9.Alloy according to any of the claims 1, 2, 3, comprising (in. wt %); 7.0% to 9,0% Cobalt (Co), Tron (7e), 13.5% to 16.0% Chromium (Cr) 1.2% to 1.8% Molybdenum fli10), 2.2% to 2.87 Tungsten (W), 4.2% to 4.8% Aluminum (Al), 4.0% to 6.0% Tantalum (Ta), 0.04% to 0.08% Carbon (c), 0,u05% to 0.015% Zirconium (Zr), 0.005% to 0.015% Boron (B), 0.05% to 0.2% Hafnium (11f),SO0.005% to 0.05% Silicon. (Si), 0.031 to 0.2% of Yttrium (1).Alloy according to Claim 9, comprising (in. wt%): 8.0% Cobalt. (Co), 8.0%. ?ran (Fe), 1.5.0% Chromium (Cr), 1.51 Molybdenum (Mo), 2.5% Tungsten (81), 4.5% Aluminum. (Al), 5.0% Tantalum (Ta), 0.05% Carbon (C), 0.01% Zirconium (Zr), 0.1% Hat ni urn (Hf), 0.01% Silicon (Si), 0.05% Yttrium (Y), 11. Ailey according to any of the claims 1, 2, comprising (in. wt%) 7.0% to 9.0% Cobalt. (C0), 9.0% Iron (Fe.), 13.5% to 16,0% Chromium (Cr) 0.7% to 1,7% Molybdenum (Mo), 2.0% to 4.0% Tungsten. (W), 4.2% to 4.8% Aluminum (Al) 4.0% to 6.0% Tantalum (Ta), 0.03% to 0.08% Carbon (C), 0.005% LO 0.015% Zirconium (Zr), 0.005% to 0.015% Boron (B), 0.05% to 0.2% Hafnium (Hf), 0.u0.50 to 0.05% Silicon (Si) 0.01% to 0.15% of Yttrium (Y), 0.01% to 0.15% of Lanthanum (La) so 7, A:11ov according to cit-A.Hm 11, comprising. (in wt%): 8.0% Cobalt (Co), 8.0% Iron (Fe), 15.0% Chromium (Cr), 1.5% Molybdenum. (.H....))" 2.5% Tungsten (W), 4.5% Aluminum,flt,, 1.0 5.0% Tantalum (Ta)" 0.85% Carton. (CD, 0.01%. Zirconium (Zr)" 0.1% Hafnium fldf), 0.01% Silicon (Si), 0.025% Yttrium. (Y), 0.025% Lanthanum. (La).tu. Alloy according to any of the claims 1, comprising. (in wt%) 7.0% to 9.03 Cobalt (Co), 7.0% to 9.0% Iron (Fe), 13.5 to 16.0(2 Chromium 2.0% to to 1.7 Molybdenum -(MO), 4,0% Tungsten (, to 4.9% Aluminum (Al), 4.0% to 6.0% Tantalum (Ta), 0.03% to 0.03% Carbon (C), 2, 3, 0.005% to 0.015% Zirconium (Zr), 0.005(2 LO 0.015% Boron (R), 0.05% to 0.2% Hafnium (4f), 0.005% to 0.05% Silicon (Si), 0.02% to 0.2% or the sum of rare sarCbs such as Scandium (50), Yttrium (Y), the Actinides and/or the Lanthanides, Powder comprising particles made of the ai.LOy according to any or the previous claims, optionally comprising binder for binder jet printing or abrasive particles for seals.Component made of the alloy according of the previous claims I to 13, 16. Component, on which material is added by welding, printing using an alloy according * D any of the previous (HIFI-juts I to 13 or a powder according to claim 13.Component according to claim 15, which is additively manAfacturedi Comp)nemt according to claim 1H, which is casted using an alloy according to any of the previous claims I to 13, 19. Method to a component by casting us.r nc an alloy according to any of the previous claims 1 to 13.20, Method to produce a component by addi hive. manufac-turing using an. alloy according to any of. the previous claims 1 to 13.