JP5791998B2 - Nickel-iron base alloy and method for forming nickel-iron base alloy - Google Patents

Description

  The present invention relates to an alloy, an article containing the alloy, and a method for producing the alloy. Specifically, the present invention relates to a nickel-iron base alloy and a method for producing a nickel-iron base alloy.

  Operating temperatures within gas turbine engines are severe both thermally and chemically. Great progress in high temperature performance has been achieved through the development of iron-based, nickel-based and cobalt-based superalloys and the use of environmental coatings that can protect the superalloys from oxidation, thermal corrosion, etc. Development of coating systems continues to improve.

  In the compressor portion of the gas turbine engine, the atmosphere is compressed to 10 to 25 times the atmospheric pressure, and in this process is adiabatically heated to 800 ° to 1250 ° F. (427 ° C. to 677 ° C.). This heated and compressed air is sent to a combustor where it is mixed with fuel. The fuel is ignited and in the course of its combustion, the gas is heated to a very high temperature exceeding 3000 ° F. (1650 ° C.). These hot gases pass through the turbine and the exhaust system. In the turbine, the airfoils fixed to the rotating turbine disk extract the energy that drives the engine fans and compressors, and in the exhaust system, the gas provides sufficient thrust to propel the aircraft. In order to improve the operating efficiency of the engine, the combustion temperature is increased. Of course, as the combustion temperature rises, measures must be taken to prevent thermal decomposition of the materials forming these hot combustion gas passages.

  The demand for improved performance continues to increase. Because of this demand for improved performance, new engines and proven design modifications are required. Such performance requirements include, among other things, improved thrust and improved fuel economy. In order to improve the performance of the engine, the combustion temperature is raised to a very high temperature. As a result, high driving force and / or excellent fuel economy can be obtained.

  The stator parts (nozzles and shrouds) are the hot gas path parts of the gas turbine. The stator component desirably has oxidation resistance, thermal-mechanical fatigue performance and high temperature creep strength. Traditionally, stator components are made of Ni-based or Co-based cast superalloys. These superalloys have the disadvantage that they can be very expensive.

  Known attempts to use various materials have been unsuccessful. For example, state-of-the-art stainless steels (eg, Alumina-Forming Austenitic (AFA) alloys developed by Oak Ridge National Laboratory) contain nanoprecipitates and oxide-forming elements and exhibit significant heat resistance. . However, these latest stainless steels have creep strengths that are inconvenient for nozzles. In particular, the creep strength of these advanced stainless steels is only about half of the design requirements for gas turbine nozzles.

  Another group of low cost materials, nickel-iron based superalloys, such as A286, INCOLOY® 901, INCOLOY® 903 and IN706, are believed to have several disadvantages. “INCOLOY” is a US registered trademark of an alloy manufactured by Inco Alloys International (Huntington, WV, USA). For example, INCOLOY® 901 lacks a γ ′ phase (resulting in low creep strength) and contains significant amounts of η, σ and Laves phases (resulting in low ductility and / or Or resulting in poor long-term mechanical properties), a wide solidification range and poor castability.

U.S. Pat. No. 7,730,616

  Nickel-iron base alloys and methods of forming nickel-iron base alloys that do not have the above disadvantages are desirable in the art.

  Nickel-iron-based alloys according to exemplary embodiments of the present disclosure can have a weight of about 0.06% to about 0.09% C, about 35% to about 37% Fe, about 12.0% to About 16.5% Cr, about 1.0% to about 2.0% Al, about 1.0% to about 3.0% Ti, about 1.5% to about 3.0% W, About 5.0% or less Mo, about 0.75% or less Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% or less B, the balance being It is substantially Ni.

  In another exemplary embodiment of the present disclosure, the nickel-iron based alloy has a solidification range of less than about 110 ° F., a γ ′ solvus greater than about 1700 ° F., a substantially zero η phase, less than about 5%. Laves phase, less than about 5% sigma phase and lacks Co.

  In yet another exemplary embodiment of the present disclosure, a method of forming a modified alloy comprises preparing a base alloy composition, confirming a plurality of predetermined properties, modifying the base alloy composition, and Forming a modified alloy composition having predetermined properties. The plurality of predetermined characteristics include having a solidification range of less than about 110 ° F., having a γ ′ solvus greater than about 1700 ° F., having substantially no η phase, and less than about 5%. Includes having a Laves phase and having a σ phase of less than about 5%. The base alloy composition is about 0.05% C, about 36% Fe, about 12.50% Cr, about 0.20% Al, about 2.80% Ti, about 0.12% or less. W, about 5.70% Mo, about 0.1% or less Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% or less B, and the balance A first composition consisting essentially of Ni, and about 0.02% C, about 37% Fe, 16.00% Cr, about 0.20% Al, about 1.75% Ti About 0.12% W, about 0.12% Mo, about 2.90% Nb, about 0.2% Mn, about 0.1% Si, about 0.006% 1 or more types of the 2nd composition which contains following B and the balance consists essentially of Ni are included.

  One advantage of embodiments of the present disclosure is a modified alloy that has the desired creep strength by forming a sufficient amount of γ ′ phase and reducing or eliminating the η phase.

  Another advantage of embodiments of the present disclosure is a modified alloy having desirable ductility and / or long-term mechanical properties.

  Yet another advantage of embodiments of the present disclosure is a modified alloy having desirable castability.

  Other features and advantages of the present invention will become apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.

  A nickel-iron base alloy having a plurality of predetermined characteristics and a method of forming a nickel-iron base alloy having a plurality of predetermined characteristics are provided.

  Embodiments of the present disclosure include a nickel-iron based alloy formed from one or more low cost alloys that were previously considered unsuitable as hot gas path components such as engine turbine stators. This nickel-iron base alloy has the desired creep strength as a result of not containing the η phase. The nickel-iron base alloy has desirable ductility and / or long-term mechanical properties. The nickel-iron base alloy also has desirable castability.

  The nickel-iron base alloy can be formed by any suitable method. In one embodiment, the nickel-iron base alloy has a creep rupture life of about 1000 hours at a load of about 25 ksi to about 30 ksi at about 1400 degrees Fahrenheit. In one embodiment, the nickel-iron based alloy is resistant to oxidation for 48000 hours. In one embodiment, the low cycle fatigue of the modified alloy is substantially the same as the FSX414 alloy.

  In one embodiment, the method includes providing a base alloy. This base alloy is one or more alloys that have previously been considered undesirable for hot gas path components. For example, in one embodiment, the base alloy is base alloy 1. As used herein, “base alloy 1” refers to about 0.05% C, about 0.20% Al, about 2.80% Ti, about 12.50% Cr, about 5 Refers to alloys having a composition of 70% Mo, about 36% Fe, and other suitable elements (throughout this disclosure, all percentages are by weight unless otherwise stated). In one embodiment, the base alloy 1 further comprises about 0.12% or less W, about 0.1% or less Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006. Including B below, the balance is substantially Ni. In an additional embodiment, the base alloy 1 does not contain Co.

  In another embodiment, the base alloy is base alloy 2. As used herein, “base alloy 2” refers to about 16.00% Cr, about 37% Fe, about 2.90% Nb, about 1.75% Ti, about 0.20. %, Al, about 0.02% C, and other suitable elemental alloys. In one embodiment, the base alloy 2 further comprises about 0.12% or less W, about 0.2% or less Mn, about 0.1% or less Si, about 0.006 or less B, with the balance being substantially Ni. In an additional embodiment, the base alloy 2 does not contain Co.

  The method then confirms a plurality of predetermined properties desired for the modified alloy. Data corresponding to a plurality of predetermined characteristics can be analyzed by a program executed by a computer, such as a computer thermodynamic modeling program. A program executed by the computer correlates data about the base alloy and generates an output of properties corresponding to the modified alloy. This generated output is based on a modification to the composition of the base alloy that forms the modified alloy. This analysis of the generated output allows identification of one or more compositions to be further analyzed.

  This property includes any suitable quantifiable property. These properties include solidification range, γ ′ solvus, η phase depletion, Laves phase percentage, σ phase percentage, Laves phase formation temperature, other suitable properties, or any combination thereof. In one embodiment, the solidification range is less than about 110 ° F. resulting in good castability. In one embodiment, the γ ′ solvus is greater than about 1700 ° F. In one embodiment, the lack of η phase includes lack of η phase. In one embodiment, the Laves σ percent is less than about 5%. In one embodiment, the formation temperature is less than about 1200 ° F.

  The relationship between the data relating to the base alloy and the output of properties corresponding to the nickel-iron base alloy can include any suitable relationship between the modification of the composition of the base alloy and the affected properties. For example, Al reduces the η phase. Inclusion of Al at a concentration greater than about 1% eliminates the η phase. Thus, the data association can produce an output indicating the absence of η phase for concentrations of Al above about 1%. Other relationships that can be related are that increasing the concentration of Mo increases the η phase, increasing the concentration of W reduces the η phase, increasing the concentration of Al reduces the solidification range, and these It is a combination. Combined associations can also be used. For example, when Al is about 0.8%, increasing the concentration of W increases solidification. However, when Al is about 1.5%, increasing the concentration of W reduces solidification. Therefore, the concentration of Al and the concentration of W can be related in this connection.

  This association can further include additional experimental data based on analysis of parts formed of nickel-iron base alloys and comparison of predetermined properties of various compositions of nickel-iron base alloys. For example, these data include specific chemical properties, scaled-up heating, long-term microstructure stability studies, long-term oxidation tests, creep tests (eg, 5000 hour creep test) and other mechanical properties. Any combination of tests may be mentioned.

  Based on this association, the base alloy used and the modified nickel-iron base alloy to be formed on the part are selected (manually or automatically). The part can be formed by any suitable technique (eg, casting, forging, heat treatment, repair welding, or any suitable combination thereof).

  In one embodiment, the nickel-iron based alloy comprises about 0.07% to about 0.09% C, about 35% to about 37% Fe, about 12.0% to about 16.5% Cr, About 1.0% to about 2.0% Al, about 2.0% to about 3.0% Ti, about 2.0% to about 3.0% W, about 3.0% to about 5 0.0% Mo, about 0.1% or less Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% B, and the balance being substantially Ni Includes composition range. In additional embodiments, the nickel-iron based alloy comprises about 0.07% to about 0.09% C, about 35% to about 37% Fe, about 12.0% to about 13.0% Cr. About 1.35% to about 1.65% Al, about 2.25% to about 2.75% Ti, about 2.3% to about 2.7% W, about 3.4% to about 3.6% Mo, about 0.1% or less Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% or less B, and the balance being substantially Ni The composition range of In additional embodiments, the nickel-iron based alloy lacks Co.

  In another embodiment, the nickel-iron based alloy comprises about 0.07% to about 0.09% C, about 35% to about 37% Fe, about 12.0% to about 16.5% Cr. About 1.0% to about 2.0% Al, about 2.0% to about 3.0% Ti, about 1.5% to about 2.5% W, about 3.0% to about 5.0% Mo, about 0.1% or less Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% or less B, and the balance being substantially Ni The composition range of In additional embodiments, the nickel-iron based alloy comprises about 0.07% to about 0.09% C, about 35% to about 37% Fe, about 13.5% to about 14.5% Cr. About 1.35% to about 1.65% Al, about 2.25% to about 2.75% Ti, about 1.8% to about 2.2% W, about 3.9% to about 4.1% Mo, about 0.1% or less Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% or less B, and the balance being substantially Ni The composition range of In additional embodiments, the nickel-iron based alloy lacks Co.

  In one embodiment, the nickel-iron based alloy comprises about 0.07% to about 0.09% C, about 35% to about 37% Fe, about 12.0% to about 16.5% Cr, About 1.0% to about 2.0% Al, about 2.0% to about 3.0% Ti, about 1.5% to about 2.5% W, about 0.5% to about 1 .5% Mo, about 0.1% or less Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% or less B, and the balance being substantially Ni Includes composition range. In additional embodiments, the nickel-iron based alloy comprises about 0.07% to about 0.09% C, about 35% to about 37% Fe, about 15.5% to about 16.5% Cr. About 1.35% to about 1.65% Al; about 2.25% to about 2.75% Ti; about 1.8% to about 2.2% W; about 0.9% to about 1.1% Mo, about 0.1% or less Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% or less B, and the balance being substantially Ni The composition range of In additional embodiments, the nickel-iron based alloy lacks Co.

  In one embodiment, the nickel-iron based alloy comprises about 0.06% to about 0.08% C, about 35% to about 37% Fe, about 12.0% to about 16.5% Cr, About 1.0% to about 2.0% Al, about 1.0% to about 2.5% Ti, about 1.5% to about 2.5% W, and about 0.25% or less Mo About 0.25% to about 0.75% Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% or less B, and the balance being substantially Ni Includes composition range. In additional embodiments, the nickel-iron based alloy comprises about 0.06% to about 0.08% C, about 35% to about 37% Fe, about 15.5% to about 16.5% Cr. About 1.35% to about 1.65% Al, about 1.5% to about 1.8% Ti, about 1.8% to about 2.2% W, about 0.12% or less Mo, about 0.4% to about 0.6% Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% or less B, and the balance being substantially Ni The composition range of In additional embodiments, the nickel-iron based alloy lacks Co.

  In one embodiment, the nickel-iron-based alloy can have a composition that is based on the composition of the base alloy 1 originally. In one embodiment, the nickel-iron based alloy comprises about 0.08% C, about 36% Fe, about 12.5% Cr, about 1.50% Al, about 2.50% Ti, About 2.50% W, about 3.50% Mo, about 0.1% or less Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% or less B and the balance substantially contain Ni. In yet another embodiment, the nickel-iron based alloy comprises about 0.08% C, about 36% Fe, about 14.0% Cr, about 1.50% Al, about 2.50%. Ti, about 2.50% W, about 4.00% Mo, about 0.1% or less Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% The following B and the balance substantially contain a composition of Ni. In yet another embodiment, the nickel-iron based alloy comprises about 0.08% C, about 36% Fe, about 16.0% Cr, about 1.50% Al, about 2.50%. Ti, about 2.50% W, about 1.00% Mo, about 0.1% or less Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% The following B and the balance substantially contain a composition of Ni.

  In one embodiment, the nickel-iron-based alloy can have a composition that is based on the composition of the base alloy 2 originally. In one embodiment, the nickel-iron based alloy comprises about 0.07% C, about 37% Fe, about 16.0% Cr, about 1.50% Al, about 1.75% Ti, About 2.00% W, about 0.12% or less Mo, about 0.50% Nb, about 0.2% or less Mn, about 0.1% or less Si, about 0.006% or less B and the balance substantially contain Ni.

  In one embodiment, the alloy composition is used in high temperature gas turbine components. For example, the alloy can be used in stator components including, but not limited to, nozzles, shrouds, other suitable parts, or combinations thereof.

  Although the present invention has been described with reference to preferred embodiments, it will be understood by those skilled in the art that various modifications can be made without departing from the scope of the present invention, and that the elements are equivalent. Can be replaced. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Accordingly, the invention is not limited to the specific embodiments disclosed as the best mode contemplated for carrying out the invention, but encompasses any embodiment falling within the scope of the claims.

Claims (10)

By weight, 0 . 06% to 0 . 09% of C, 3 of 5% ~ 3 7% Fe, 1 2.0% ~ 1 6.5% of Cr, 1. 0% to 2. 0% Al, 1 . 0% to 3 . 0% Ti, 1 . 5% -3 . 0% W, 5 . 0% or less of Mo, 0 . 75% or less Nb, 0 . 2% or less of Mn, 0 . 1% or less of Si, 0 . Wherein 006% or less of B, the nickel balance being N i - iron-base alloy. 0 . 07% to 0 . 09% C, 2 . 0% to 3 . 0% Ti, 2 . 0% to 3 . 0% W, 3 . 0% to 5 . 0% Mo and 0 . The alloy of claim 1, comprising 1% or less Nb. 0 . 07% to 0 . 09% C, 2 . 0% to 3 . 0% Ti, 1 . 5% to 2. 5% W, 3 . 0% to 5 . 0% Mo and 0 . The alloy of claim 1, comprising 1% or less Nb. 0 . 07% to 0 . 09% C, 2 . 0% to 3 . 0% Ti, 1 . 5% to 2. 5% W, 0 . 5-1. 5% Mo and 0 . The alloy of claim 1, comprising 1% or less Nb. 0 . 06% to 0 . 08% C, 1 . 0% to 2. 5% Ti, 1 . 5% to 2. 5% W, 0 . 25% or less of Mo and 0.25% to 0 . The alloy of claim 1 comprising 75% Nb. 0 . 07% to 0 . 09% C, 1 2.0% to 1 3.0% Cr, 1 . 35% to 1 . 65% Al, 2 . 25% to 2. 75% Ti, 2 . 3% to 2. 7% W, 3 . 4% -3 . 6% Mo, 0 . The alloy of claim 1, comprising 1% or less Nb. 0 . 07% to 0 . 09% C, 1 3.5% to 1 4.5% Cr, 1 . 35% to 1 . 65% Al, 2 . 25% to 2. 75% Ti, 1 . 8% to 2. 2% W, 3 . 9% to 4. 1% Mo, 0 . The alloy of claim 1, comprising 1% or less Nb. 0 . 07% to 0 . 09% of C, 1 5.5% ~ 1 6.5 % of Cr, 1. 35% to 1 . 65% Al, 2 . 25% to 2. 75% Ti, 1 . 8% to 2. 2% W, 0 . 9% to 1 . 1% Mo, 0 . The alloy of claim 1, comprising 1% or less Nb. 0 . 06% to 0 . 08% of C, 1 5.5% ~ 1 6.5 % of Cr, 1. 35% to 1 . 65% Al, 1 . 5% to 1 . 8% Ti, 1 . 8% to 2. 2% W, 0 . 12% or less of Mo, 0 . 4% to 0 . The alloy of claim 1 comprising 6% Nb. Alloy, solidification range of less than 110 ° F (43.3 ℃), 1 700 ° F (927 ℃) more than gamma 'solvus, and have a Laves phase and less than 5% of the σ phase less than 5%, The alloy according to claim 1 , which does not contain a η phase .