WO2003040419A1 - Method for developing a nickel-base super alloy - Google Patents

Method for developing a nickel-base super alloy Download PDF

Info

Publication number
WO2003040419A1
WO2003040419A1 PCT/IB2002/004619 IB0204619W WO03040419A1 WO 2003040419 A1 WO2003040419 A1 WO 2003040419A1 IB 0204619 W IB0204619 W IB 0204619W WO 03040419 A1 WO03040419 A1 WO 03040419A1
Authority
WO
WIPO (PCT)
Prior art keywords
phase
nickel
degradation
room temperature
lattice
Prior art date
Application number
PCT/IB2002/004619
Other languages
German (de)
French (fr)
Inventor
Mohamed Nazmy
Original Assignee
Alstom Technology Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alstom Technology Ltd filed Critical Alstom Technology Ltd
Priority to EP02779820A priority Critical patent/EP1451382A1/en
Publication of WO2003040419A1 publication Critical patent/WO2003040419A1/en
Priority to US10/838,353 priority patent/US20040261921A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C19/00—Alloys based on nickel or cobalt
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C1/00—Making non-ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B11/00—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10—Inorganic compounds or compositions
    • C30B29/52—Alloys

Definitions

  • the invention relates to a method for developing a nickel-based superalloy, which is used to produce a single-crystalline or directionally solidified material body.
  • a whole series of nickel-based superalloys are known from the prior art, which are used for the production of single-crystalline or directionally solidified material bodies. Such material bodies are such.
  • the material strength at high temperatures can be maximized, which in turn can increase the inlet temperature of gas turbines, which leads to an increase in the efficiency of the gas turbine.
  • Nickel-based superalloys are, for example, the alloys CMSX-2, CMSX-4, CMSX-10, Rene N5, Rene N6, PWA 1484 and PWA 1483, the composition of which, for. B. from GL Erickson: Corrosion resistant Single Crystal Superalloys for Industrial Gas Turbine Application, International Gas & Turbine Aeroengine Congress & Exhibition, Orlando, Florida, June 2-June 5, 1997. Alloys of this type are subjected to a heat treatment after the casting process, in which, in a first solution-annealing step, the ⁇ '-phase which has precipitated out unevenly during the casting process is completely or partially dissolved. In a second heat treatment step, this phase is eliminated in a controlled manner. In order to achieve optimum properties, this precipitation heat treatment is carried out in such a way that fine, uniformly distributed particles of the ⁇ '-phase are formed in the ⁇ -phase.
  • the invention tries to avoid the disadvantages of the known prior art. It is based on the task of creating a method for developing nickel-based superalloys which is based on a new, simple concept.
  • the advantages of the invention are that it is relatively easy to develop nickel-based superalloys with an optimized degradation behavior using this method.
  • a high positive lattice offset ⁇ between the ⁇ -phase and the ⁇ '-phase is selected, the degradation of the properties is less pronounced, ie the Yield loss in the degraded state compared to the non-degraded state is only slight.
  • the numbers in front of the element symbols indicate the relative atomic fractions of the respective elements in the ⁇ '-phase.
  • the yield strength ⁇ o, 2 is determined for different nickel-based superalloys at room temperature in the degraded state as a function of the degradation parameter, and those alloys are selected which have the smallest difference in the yield strengths between the initial state and the degraded state, i.e. those alloys which have the highest possible yield strength values in the degraded state.
  • Fig. 1 shows the dependence of the yield strength after degradation at room temperature on the lattice offset between the ⁇ -phase and the ⁇ '-phase for different known nickel-based superalloys and
  • Fig. 2 shows the dependence of the yield strength at room temperature on the degradation parameter for different known nickel-based superalloys.
  • the lattice offset ⁇ between the ⁇ -phase and the ⁇ '-phase at room temperature is in the range of approx. - 0.24% to + 0.58% for the alloys examined. With an increase in the positive replacement, the yield strength ⁇ o , 2 also increases after degradation at room temperature. Of the alloys examined, alloy PW1480 has the highest positive lattice offset ⁇ between the ⁇ -phase and the ⁇ '-phase and consequently also the highest yield strength ⁇ 0.2 after degradation at room temperature.
  • the lattice constants of the ⁇ -phase a ⁇ and the ⁇ '-phase a ⁇ - were known per se according to the following (see P.
  • alloying elements B, Zr and C do not play a significant role in relation to the lattice offset, especially since they are only present in small amounts as trace elements.
  • the degradation behavior of the alloy can now be optimized according to the invention by setting the highest possible positive lattice offset ⁇ between the ⁇ -phase and the ⁇ '-phase by varying the composition.
  • a degradation parameter D was introduced for the nickel-based alloys, which is determined according to the following relationship:
  • the yield strength ⁇ o, 2 is then determined at room temperature after degradation as a function of the degradation parameter. 2, these values are plotted against one another for the alloys from Table 1. In order to optimize properties, the yield point at room temperature should be as high as possible for the various degradation parameters.
  • the alloy PW1480 which has a lattice offset ⁇ between the ⁇ -phase and the ⁇ '-phase of + 0.58%, best meets this requirement.
  • the alloy CMSX4 which with a lattice shift ⁇ between the ⁇ -phase and the ⁇ '-phase of ⁇ 0.24% is the most below the requirement of the invention, has, depending on the degradation parameter D, which is at least about 5000 KhMPa, the lowest values of the yield strength. This alloy should therefore be unsuitable in terms of degradation behavior.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)

Abstract

The invention relates to a method for developing a nickel-base super alloy, consisting of a gamma phase and a gamma ' phase, for the production of monocrystalline or specifically solidified substance bodies. The invention is characterized in that the properties of nickel-base super alloys, exhibiting a volume proportion of at least 50 %, are optimized after degradation at room temperature, by selecting the composition of the alloy in such a way that a high as possible positive lattice dislocation (delta) is obtained at room temperature between the gamma phase and the gamma ' phase. As a result the apparent limit of elasticity at room temperature after degradation is relatively high and only a small difference of apparent limits of elasticity occurs between the initial state and a degraded state.

Description

Verfahren zur Entwicklung einer Nickel-Basis-Superlegierung Process for the development of a nickel-based superalloy
Technisches GebietTechnical field
Die Erfindung betrifft ein Verfahren zur Entwicklung einer Nickel-Basis- Superlegierung, welche zur Herstellung eines einkristallinen oder gerichtet erstarrten Werkstoffkörper verwendet wird.The invention relates to a method for developing a nickel-based superalloy, which is used to produce a single-crystalline or directionally solidified material body.
Stand der TechnikState of the art
Aus dem Stand der Technik sind eine ganze Reihe von Nickel-Basis- Superlegierungen bekannt, welche zur Herstellung von einkristallinen oder gerichtet erstarrten Werkstoffkörpern verwendet werden. Derartige Werkstoffkörper werden z. B. im Kraftwerksbau bei hoher Temperaturbeanspruchung eingesetzt. Mittels dieser Einkristall-Komponenten kann beispielsweise die Materialfestigkeit bei hohen Temperaturen maximiert werden, wodurch wiederum die Einlasstemperatur von Gasturbinen erhöht werden kann, was zu einer Steigerung der Effizienz der Gasturbine führt.A whole series of nickel-based superalloys are known from the prior art, which are used for the production of single-crystalline or directionally solidified material bodies. Such material bodies are such. B. used in power plant construction at high temperatures. By means of these single crystal components, for example, the material strength at high temperatures can be maximized, which in turn can increase the inlet temperature of gas turbines, which leads to an increase in the efficiency of the gas turbine.
Bisher wurden derartige Legierungen nach folgenden Konzepten entwickelt:So far, such alloys have been developed according to the following concepts:
- Erhöhung der Zeitstandfestigkeit- Increase in creep strength
- Erhöhung des Oxidations- und Korrosionswiderstandes - Erhöhung des Widerstandes gegen Risswachstum, insbesondere gegen LCF (Low Cycle Fatigue = Ermüdung bei niedrigen Lastspielzahlen)- Increased resistance to oxidation and corrosion - Increased resistance to crack growth, especially against LCF (Low Cycle Fatigue = fatigue with low number of cycles)
- Verbesserung der Giessbarkeit und der Wärmebehandlungsmöglichkeiten- Improve the pourability and the heat treatment options
- Senkung der Kosten. Bekannte Nickel-Basis-Superlegierungen sind beispielsweise die Legierungen CMSX-2, CMSX-4, CMSX-10, Rene N5, Rene N6, PWA 1484 und PWA 1483, deren Zusammensetzung z. B. aus G. L. Erickson: Corrosion resistant Single Crystal Superalloys for Industrial Gas Turbine Application, International Gas & Turbine Aeroengine Congress & Exhibition, Orlando, Florida, June 2-June 5, 1997 entnehmbar ist. Derartige Legierungen werden nach dem Giessprozess einer Wärmebehandlung unterzogen, bei der in einem ersten Lösungsglühschritt die während des Giessprozesses ungleichmässig ausgeschiedene γ'-Phase ganz oder teilweise aufgelöst wird. In einem zweiten Wärmebehandlungsschritt wird diese Phase wieder kontrolliert ausgeschieden. Um optimale Eigenschaften zu erzielen, wird diese Ausscheidungswärmebehandlung derart durchgeführt, dass feine gleichmässig verteilte Teilchen der γ'-Phase in der γ-Phase entstehen.- Lower costs. Known nickel-based superalloys are, for example, the alloys CMSX-2, CMSX-4, CMSX-10, Rene N5, Rene N6, PWA 1484 and PWA 1483, the composition of which, for. B. from GL Erickson: Corrosion resistant Single Crystal Superalloys for Industrial Gas Turbine Application, International Gas & Turbine Aeroengine Congress & Exhibition, Orlando, Florida, June 2-June 5, 1997. Alloys of this type are subjected to a heat treatment after the casting process, in which, in a first solution-annealing step, the γ'-phase which has precipitated out unevenly during the casting process is completely or partially dissolved. In a second heat treatment step, this phase is eliminated in a controlled manner. In order to achieve optimum properties, this precipitation heat treatment is carried out in such a way that fine, uniformly distributed particles of the γ'-phase are formed in the γ-phase.
Bekannt ist, dass der Gitterversatz eine entscheidende Rolle für die Zeitstandfestigkeit bei hohen Temperaturen spielen kann. Viele der bekannten Nickel-Basis-Superlegierungen weisen einen positiven oder negativen Gitterversatz zwischen der γ-Matrix und der γ'-Phase auf. Durch diese Gitterverzerrung werden Versetzungen beim Gleiten oder Schneiden von γ'- Körnern behindert, was eine Erhöhung der Kurzzeitfestigkeit bei erhöhten Temperaturen bewirkt. Während einerseits in der Literatur für Nickel-Basis- Superlegierungen bei Raumtemperatur ein negativer Gitterversatz mit möglichst hoher Amplitude gefordert wird (P. Caron: High γ' solvus new generation nickel- based superalloys for Single crystal turbine blade applications. Proceedings of the 9th international Symposium on Superalloys - SUPERALLOY 2000, p.737-746, Champion, USA, September 17-21 , 2000), werden andere Nickel-Basis- Superlegierungen (siehe beispielsweise EP 0 914 483 B1) durch eine entsprechende Wahl der Zusatzelemente so konzipiert, dass kein Gitterversatz vorhanden ist, weil festgestellt wurde, dass durch den Gitterversatz zwischen γ- und γ'-Phase beim Vorliegen einer massigen oder tiefen mechanischen Beanspruchung langfristig bei hohen Temperaturen eine gerichtete Korn- Vergröberung der γ'-Teilchen und anschliessend eine Degradation der γ'-Struktur entsteht. Darstellung der ErfindungIt is known that the lattice offset can play a decisive role in the creep rupture strength at high temperatures. Many of the known nickel-based superalloys have a positive or negative lattice offset between the γ-matrix and the γ'-phase. This lattice distortion prevents dislocations when sliding or cutting γ 'grains, which increases the short-term strength at elevated temperatures. On the one hand, in the literature for nickel-based superalloys at room temperature, a negative lattice offset with the highest possible amplitude is required (P. Caron: High γ 'solvus new generation nickel-based superalloys for Single crystal turbine blade applications. Proceedings of the 9 th international Symposium on Superalloys - SUPERALLOY 2000, p.737-746, Champion, USA, September 17-21, 2000), other nickel-based superalloys (see for example EP 0 914 483 B1) are designed by a corresponding choice of additional elements, that there is no lattice misalignment because it was determined that the lattice misalignment between the γ and γ 'phases in the presence of massive or deep mechanical stresses in the long term at high temperatures caused a directional grain coarsening of the γ' particles and subsequently a degradation of the γ 'Structure emerges. Presentation of the invention
Die Erfindung versucht, die Nachteile des bekannten Standes der Technik zu vermeiden. Ihr liegt die Aufgabe zugrunde, ein Verfahren zur Entwicklung von Nickel-Basis-Superlegierungen zu schaffen, welches auf einem neuen einfachen Konzept beruht.The invention tries to avoid the disadvantages of the known prior art. It is based on the task of creating a method for developing nickel-based superalloys which is based on a new, simple concept.
Diese Aufgabe wird erfindungsgemäss dadurch gelöst, dass die Eigenschaften von Nickel-Basis-Superlegierungen mit einem Volumenanteil an γ'-Phase von mindestens 50 % nach einer Degradierung bei Raumtemperatur optimiert werden, indem die Zusammensetzung der Legierung so gewählt wird, dass bei Raumtemperatur ein möglichst hoher positiver Gitterversatz δ zwischen der γ- Phase und der γ'-Phase vorhanden, wobei δ [%] = 2 (aγ-aγ)/(aγ'+aγ) und wobei aγ die Gitterkonstante der γ-Phase und aγ< die Gitterkonstante der γ'-Phase ist.This object is achieved according to the invention in that the properties of nickel-based superalloys with a volume fraction of γ′-phase of at least 50% are optimized after a degradation at room temperature by selecting the composition of the alloy so that at room temperature a high positive lattice offset δ between the γ phase and the γ'-phase, where δ [%] = 2 (a γ -a γ ) / (a γ '+ a γ ) and where a γ is the lattice constant of the γ phase and a γ <is the lattice constant of the γ 'phase.
Die Vorteile der Erfindung bestehen darin, dass es mit diesem Verfahren relativ einfach gelingt, Nickel-Basis-Superlegierungen mit einem optimierten Degradationsverhalten zu entwickeln.The advantages of the invention are that it is relatively easy to develop nickel-based superalloys with an optimized degradation behavior using this method.
Es wurde festgestellt, dass es beim Vorliegen einer mechanischen Belastung und einer langzeitigen Hochtemperaturbeanspruchung zu einer gerichteten Vergröberung der γ'-Teilchen, der sogenannten Flossbildung (rafting) kommt und, bei hohen γ'-Gehalten (d.h. bei einem γ'-Volumenanteil von mindestens 50%), zur Invertierung der MikroStruktur, d.h. γ' wird zur durchgehenden Phase, in der die frühere γ-Matrix eingebettet ist. Da die intermetallische γ'-Phase zur Umgebungsversprödung (environmental embrittlement) neigt, führt dies unter bestimmten Belastungsbedingungen zu massivem Abfall der mechanischen Eigenschaften, vor allem der Streckgrenze, bei Raumtemperatur. Die Umgebungsversprödung tritt insbesondere dann auf, wenn Feuchtigkeit und lange Haltezeiten unter Zugbelastung vorliegen. Wird erfindungsgemäss ein hoher positiver Gitterversatz δ zwischen der γ-Phase und der γ'-Phase gewählt, dann ist die Degradierung der Eigenschaften weniger stark ausgeprägt, d.h. der Streckgrenzenverlust im degradierten Zustand gegenüber dem nicht degradierten Zustand ist nur gering.It was found that there is a directional coarsening of the γ ' particles, the so-called rafting, when there is mechanical stress and long-term high-temperature stress, and, at high γ ' contents (i.e. with a γ ' volume fraction of at least 50%), for inverting the microstructure, ie γ ' becomes the continuous phase in which the previous γ matrix is embedded. Since the intermetallic γ ' phase tends towards environmental embrittlement, this leads to a massive drop in the mechanical properties, especially the yield strength, at room temperature under certain load conditions. Ambient embrittlement occurs particularly when there is moisture and long holding times under tensile stress. If, according to the invention, a high positive lattice offset δ between the γ-phase and the γ'-phase is selected, the degradation of the properties is less pronounced, ie the Yield loss in the degraded state compared to the non-degraded state is only slight.
Es ist vorteilhaft, wenn die Gitterkonstanten der γ-Phase aγ und der γ'-Phase av- nach folgenden an sich bekannten Gleichungen ermittelt werden:It is advantageous if the lattice constants of the γ-phase a γ and the γ'-phase a v - are determined according to the following known equations:
aγ [Ä] = 3.524 + 0,0196Co + 0.110Cr + 0.478Mo + 0.444W + 0.441 Re + 0.3125Ru + 0.179AI + 0.422Ti + 0.7Ta + 0.7Nb,a γ [Ä] = 3,524 + 0.0196Co + 0.110Cr + 0.478Mo + 0.444W + 0.441 Re + 0.3125Ru + 0.179AI + 0.422Ti + 0.7Ta + 0.7Nb,
wobei die Zahlen vor den Elementsymbolen den relativen Atomanteil (engl. atomic fractions) der jeweiligen Elemente in der γ-Phase angeben undthe numbers in front of the element symbols indicate the relative atomic fractions of the respective elements in the γ phase and
aγ- [Ä] = 3.57 - 0.004Cr + 0.208Mo + 0.194W + 0.262Re + 0.1335 Ru + 0.258Ti + 0.5Ta + 0.46Nb,a γ - [Ä] = 3.57 - 0.004Cr + 0.208Mo + 0.194W + 0.262Re + 0.1335 Ru + 0.258Ti + 0.5Ta + 0.46Nb,
wobei die Zahlen vor den Elementsymbolen den relativer Atomanteil (engl. atomic fractions) der jeweiligen Elemente in der γ'-Phase angeben.the numbers in front of the element symbols indicate the relative atomic fractions of the respective elements in the γ'-phase.
Zur Kennzeichnung des Zeitstandverhaltens von Nickel-Basis-Legierungen wird nun ein Degradations-Parameter D eingeführt wird, welcher nach folgender Beziehung ermittelt wird:To characterize the creep behavior of nickel-based alloys, a degradation parameter D is now introduced, which is determined according to the following relationship:
D = (T-800) t 1"/2 σ 1/5D = (T-800) t 1 "/ 2 σ 1/5
mit T = Temperatur in °K, t = Zeit in h und σ = Spannung in MPa. Es wird die Streckgrenze σo,2 für unterschiedliche Nickel-Basis-Superlegierungen bei Raumtemperatur im degradierten Zustand in Abhängigkeit vom Degradations- Parameter ermittelt und diejenigen Legierungen werden ausgewählt, welche die geringste Differenz der Streckgrenzen zwischen Ausgangszustand und degradiertem Zustand aufweisen, also diejenigen Legierungen, welche möglichst hohe Werte der Streckgrenze im degradierten Zustand aufweisen. Kurze Beschreibung der Zeichnungwith T = temperature in ° K, t = time in h and σ = stress in MPa. The yield strength σo, 2 is determined for different nickel-based superalloys at room temperature in the degraded state as a function of the degradation parameter, and those alloys are selected which have the smallest difference in the yield strengths between the initial state and the degraded state, i.e. those alloys which have the highest possible yield strength values in the degraded state. Brief description of the drawing
In der Zeichnung sind Ausführungsbeispiele der Erfindung dargestellt.Exemplary embodiments of the invention are shown in the drawing.
Es zeigen:Show it:
Fig. 1 die Abhängigkeit der Streckgrenze nach Degradierung bei Raumtemperatur vom Gitterversatz zwischen der γ-Phase und der γ'- Phase für unterschiedliche bekannte Nickel-Basis-Superlegierungen undFig. 1 shows the dependence of the yield strength after degradation at room temperature on the lattice offset between the γ-phase and the γ'-phase for different known nickel-based superalloys and
Fig. 2 die Abhängigkeit der Streckgrenze bei Raumtemperatur vom Degradations-Parameter für unterschiedliche bekannte Nickel-Basis- Superlegierungen.Fig. 2 shows the dependence of the yield strength at room temperature on the degradation parameter for different known nickel-based superalloys.
Es sind nur die für die Erfindung wesentlichen Merkmale dargestellt. Gleiche Elemente haben in unterschiedlichen Figuren gleiche Bezugszeichen.Only the features essential to the invention are shown. The same elements have the same reference symbols in different figures.
Wege zur Ausführung der ErfindungWays of Carrying Out the Invention
Nachfolgend wird die Erfindung anhand von Ausführungsbeispielen und der Figuren 1 und 2 näher erläutert.The invention is explained in more detail below on the basis of exemplary embodiments and FIGS. 1 and 2.
Es wurde festgestellt, dass es beim Vorliegen einer mechanischen Belastung und einer langzeitigen Hochtemperaturbeanspruchung zu einer gerichteten Vergröberung der γ'-Teilchen, der sogenannten Flossbildung (rafting) kommt und dass es beim Vorhandensein von hohen γ'-Gehalten (d.h. bei einem γ'- Volumenanteil von mindestens 50%) zur Invertierung der MikroStruktur kommt, d.h. γ' wird zur durchgehenden Phase, in der die frühere γ-Matrix eingebettet ist. Da die intermetallische γ'-Phase zur Umgebungsversprödung (engl.: environmental embrittlement) neigt, führt dies unter bestimmten Belastungsbedingungen zum massiven Abfall der mechanischen Eigenschaften, vor allem der Streckgrenze, bei Raumtemperatur. Es erfolgt somit eine Degradierung der Eigenschaften. Die Umgebungsversprödung tritt insbesondere dann auf, wenn Feuchtigkeit und lange Haltezeiten unter Zugbelastung vorliegen. Wird nun erfindungsgemäss eine Legierung mit einem hohen positiven Gitterversatz δ zwischen der γ-Phase und der γ'-Phase gewählt, dann ist die Degradierung der Eigenschaften weniger stark ausgeprägt, d.h. der Streckgrenzenverlust im degradierten Zustand gegenüber dem nicht degradierten Zustand ist nur gering.It was found that there is a directional coarsening of the γ ' particles, the so-called rafting, when there is mechanical stress and long-term high-temperature stress, and that there is high γ' content (ie with a γ'- Volume fraction of at least 50%) for the inversion of the microstructure, ie γ ' becomes the continuous phase in which the former γ matrix is embedded. Since the intermetallic γ ' phase for environmental embrittlement environmental embrittlement), this leads to a massive drop in mechanical properties, especially the yield strength, at room temperature under certain load conditions. The properties are therefore degraded. Ambient embrittlement occurs particularly when there is moisture and long holding times under tensile stress. If an alloy with a high positive lattice offset δ between the γ-phase and the γ'-phase is selected according to the invention, the degradation of the properties is less pronounced, ie the yield strength loss in the degraded state compared to the non-degraded state is only slight.
Die Fig. 1 zeigt für unterschiedliche bekannte Nickel-Basis-Superlegierungen, welche zur Herstellung eines einkristallinen oder gerichtet erstarrten Werkstoffkörper verwendet werden, die Abhängigkeit der Streckgrenze σo,2 nach Degradierung bei Raumtemperatur vom Gitterversatz δ zwischen der γ-Phase und der γ'-Phase. Der Gitterversatz δ zwischen der γ-Phase und der γ'-Phase wurde auf an sich bekannte Art und Weise folgendermassen berechnet: δ [%] = 2 (aγ-aγ)/(aγ+aγ) und wobei aγ die Gitterkonstante der γ-Phase ist und aγ- die Gitterkonstante der γ'- Phase ist.1 shows for different known nickel-based superalloys which are used to produce a single-crystalline or directionally solidified material body the dependence of the yield strength σo, 2 after degradation at room temperature on the lattice offset δ between the γ phase and the γ'- Phase. The lattice offset δ between the γ-phase and the γ'-phase was calculated in a manner known per se as follows: δ [%] = 2 (a γ -a γ ) / (a γ + a γ ) and where a γ is the lattice constant of the γ phase and a γ - is the lattice constant of the γ 'phase.
Es wurden Legierungen mit der in Tabelle 1 aufgeführten chemischen Zusammensetzung (Angaben in Gew.-%) herangezogen.Alloys with the chemical composition listed in Table 1 (data in% by weight) were used.
Der Gitterversatz δ zwischen der γ-Phase und der γ'-Phase bei Raumtemperatur liegt bei den untersuchten Legierungen im Bereich von ca. - 0.24 % bis + 0.58 %. Mit Zunahme des positiven Gitteπ/ersatzes steigt auch die Streckgrenze σo,2 nach Degradierung bei Raumtemperatur an. Von den untersuchten Legierungen hat die Legierung PW1480 den höchsten positiven Gitterversatz δ zwischen der γ-Phase und der γ'-Phase und demzufolge auch die höchste Streckgrenze σ0,2 nach Degradierung bei Raumtemperatur. Die Gitterkonstanten der γ-Phase aγ und der γ'-Phase aγ- wurden nach folgenden an sich bekannten (siehe P. Caron: High γ' solvus new generation nickel-based superalloys for Single crystal turbine blade applications. Proceedings of the 9th international Symposium on Superalloys - SUPERALLOY 2000, p.737-746, Champion, USA, September 17-21 , 2000) ermittelt:The lattice offset δ between the γ-phase and the γ'-phase at room temperature is in the range of approx. - 0.24% to + 0.58% for the alloys examined. With an increase in the positive replacement, the yield strength σo , 2 also increases after degradation at room temperature. Of the alloys examined, alloy PW1480 has the highest positive lattice offset δ between the γ-phase and the γ'-phase and consequently also the highest yield strength σ 0.2 after degradation at room temperature. The lattice constants of the γ-phase a γ and the γ'-phase a γ - were known per se according to the following (see P. Caron: High γ 'solvus new generation nickel-based superalloys for Single crystal turbine blade applications. Proceedings of the 9 th international Symposium on Superalloys - SUPERALLOY 2000, p.737-746, Champion, USA, September 17-21, 2000) determined:
aγ [A] = 3.524 + 0,0196Co + 0.110Cr + 0.478MO + 0.444W + 0.441 Re + 0.3125Ru + 0.179AI + 0.422Ti + 0.7Ta + 0.7Nb,a γ [A] = 3,524 + 0.0196Co + 0.110Cr + 0.478MO + 0.444W + 0.441 Re + 0.3125Ru + 0.179AI + 0.422Ti + 0.7Ta + 0.7Nb,
wobei die Zahlen vor den Elementsymbolen den relativen Atomanteil (engl.: atomic fractions) der jeweiligen Elemente in der γ-Phase angeben undwhere the numbers before the element symbols indicate the relative atomic fractions of the respective elements in the γ phase and
aγ [A] = 3.57 - 0.004Cr + 0.208Mo + 0.194W + 0.262Re + 0.1335 Ru + 0.258TΪ + 0.5Ta + 0.46Nb,a γ [A] = 3.57 - 0.004Cr + 0.208Mo + 0.194W + 0.262Re + 0.1335 Ru + 0.258TΪ + 0.5Ta + 0.46Nb,
wobei die Zahlen vor den Elementsymbolen den relativer Atomanteil (engl.: atomic fractions) der jeweiligen Elemente in der γ'-Phase angeben. Die Legierungselemente B, Zr und C spielen keine signifikante Rolle in Bezug auf den Gitterversatz, zumal sie auch nur als Spurenelemente in kleiner Menge vorhanden sind.where the numbers in front of the element symbols indicate the relative atomic fraction of the respective elements in the γ'-phase. The alloying elements B, Zr and C do not play a significant role in relation to the lattice offset, especially since they are only present in small amounts as trace elements.
Man kann nun das Degradationsverhalten der Legierung erfindungsgemäss optimieren, indem man durch Variation der Zusammensetzung einen möglichst hohen positiven Gitterversatz δ zwischen der γ-Phase und der γ'-Phase einstellt. Zur Kennzeichnung des Zeitstandverhaltens wurde für die Nickel-Basis- Legierungen ein Degradations-Parameter D eingeführt wird, welcher nach folgender Beziehung ermittelt wird:The degradation behavior of the alloy can now be optimized according to the invention by setting the highest possible positive lattice offset δ between the γ-phase and the γ'-phase by varying the composition. To characterize the creep behavior, a degradation parameter D was introduced for the nickel-based alloys, which is determined according to the following relationship:
D = (T-800) f 1/"2 σ 1/5D = (T-800) f 1 / "2 σ 1/5
mit T = Temperatur in °K, t = Zeit in h und σ = Spannung in MPa. Anschliessend wird die Streckgrenze σo,2 bei Raumtemperatur nach Degradierung in Abhängigkeit von dem besagten Degradations-Parameter ermittelt. In Fig. 2 sind für die Legierungen aus Tabelle 1 diese Werte gegeneinander aufgetragen. Zwecks Eigenschaftsoptimierung sollte die Streckgrenze bei Raumtemperatur für die verschiedenen Degradationsparameter möglichst hoch sein. Am besten erfüllt die Legierung PW1480, die bei Raumtemperatur einen Gitterversatz δ zwischen der γ-Phase und der γ'-Phase von + 0.58 % aufweist, diese Vorgabe. Die Legierung CMSX4, welche mit einem Gitterversatz δ zwischen der γ-Phase und der γ'-Phase von - 0.24 % am stärksten unter der Massgabe der Erfindung liegt, hat dagegen in Abhängigkeit vom Degradations-Parameter D, welcher mindestens etwa 5000 KhMPa beträgt, die geringsten Werte der Streckgrenze. Somit dürfte diese Legierung im Hinblick auf das Degradationsverhalten ungeeignet sein.with T = temperature in ° K, t = time in h and σ = stress in MPa. The yield strength σo, 2 is then determined at room temperature after degradation as a function of the degradation parameter. 2, these values are plotted against one another for the alloys from Table 1. In order to optimize properties, the yield point at room temperature should be as high as possible for the various degradation parameters. The alloy PW1480, which has a lattice offset δ between the γ-phase and the γ'-phase of + 0.58%, best meets this requirement. In contrast, the alloy CMSX4, which with a lattice shift δ between the γ-phase and the γ'-phase of −0.24% is the most below the requirement of the invention, has, depending on the degradation parameter D, which is at least about 5000 KhMPa, the lowest values of the yield strength. This alloy should therefore be unsuitable in terms of degradation behavior.
BezugszeichenlisteLIST OF REFERENCE NUMBERS
O"0,2 Streckgrenze δ GitterversatzO " 0.2 yield strength δ lattice offset
3γ Gitterkonstante der γ-Phase aγ- Gitterkonstante der γ'-Phase3γ lattice constant of the γ phase a γ - lattice constant of the γ 'phase
D Degradations-ParameterD degradation parameters
T Temperatur t Zeit T temperature t time
C
Figure imgf000011_0002
C
Figure imgf000011_0002
Tabelle 1 : Chemische Zusammensetzung der Legierungen in Gew.-%Table 1: Chemical composition of the alloys in% by weight
Figure imgf000011_0001
Figure imgf000011_0001

Claims

Patentansprüche claims
1. Verfahren zur Entwicklung einer Nickel-Basis-Superlegierung, bestehend aus γ- und γ'-Phase, zur Herstellung von einkristallinen oder gerichtet erstarrten Werkstoffkörpern, dadurch gekennzeichnet, dass die Eigenschaften von Nickel-Basis-Superlegierungen mit einem Volumenanteil an γ'-Phase von mindestens 50 % nach einer Degradierung bei Raumtemperatur optimiert werden, indem die Zusammensetzung der Legierung so gewählt wird, dass bei Raumtemperatur ein möglichst hoher positiver Gitterversatz (δ) zwischen der γ-Phase und der γ'-Phase vorhanden ist, wobei
Figure imgf000012_0001
und wobei aγ die Gitterkonstante der γ-Phase ist und aγ- die Gitterkonstante der γ'-Phase ist.1. Process for the development of a nickel-based superalloy consisting of γ- and γ'-phase, for the production of single-crystalline or directionally solidified material bodies, characterized in that the properties of nickel-based superalloys with a volume fraction of γ'- Phase of at least 50% after a degradation at room temperature can be optimized by selecting the composition of the alloy so that at room temperature there is as high a positive lattice offset (δ) as possible between the γ-phase and the γ'-phase, whereby
Figure imgf000012_0001
and where a γ is the lattice constant of the γ phase and a γ - is the lattice constant of the γ 'phase.
2. Verfahren nach Anspruch 1 , dadurch gekennzeichnet, dass die Gitterkonstante der γ-Phase (aγ) und die Gitterkonstante der γ'-Phase (aγ) nach folgenden an sich bekannten Gleichungen ermittelt werden: aγ [A] = 3.524 + 0,0196Co + 0.110Cr + 0.478Mo + 0.444W + 0.441 Re2. The method according to claim 1, characterized in that the lattice constant of the γ phase (a γ ) and the lattice constant of the γ'-phase (a γ ) are determined according to the following known equations: a γ [A] = 3,524 + 0.0196Co + 0.110Cr + 0.478Mo + 0.444W + 0.441 Re
+ 0.3125Ru + 0.179AI + 0.422Ti + 0.7Ta + 0.7Nb, wobei die Zahlen vor den Elementsymbolen den relativen Atomanteil der jeweiligen Elemente in der γ-Phase angeben und a [A] = 3.57 - 0.004Cr + 0.208Mo + 0.194W + 0.262Re + 0.1335 Ru + 0.258Ti + 0.5Ta + 0.46Nb, wobei die Zahlen vor den Elementsymbolen den relativen Atomanteil der jeweiligen Elemente in der γ'-Phase angeben. Verfahren nach Anspruch 1 , dadurch gekennzeichnet, dass zur Kennzeichnung des Zeitstandverhaltens von Nickel-Basis-Legierungen ein Degradations-Parameter (D) eingeführt wird, welcher nach folgender Beziehung ermittelt wird:+ 0.3125Ru + 0.179AI + 0.422Ti + 0.7Ta + 0.7Nb, where the numbers in front of the element symbols indicate the relative atomic proportion of the respective elements in the γ phase and a [A] = 3.57 - 0.004Cr + 0.208Mo + 0.194W + 0.262Re + 0.1335 Ru + 0.258Ti + 0.5Ta + 0.46Nb, where the numbers in front of the element symbols indicate the relative atomic proportion of the respective elements in the γ'-phase. A method according to claim 1, characterized in that a degradation parameter (D) is introduced to identify the creep behavior of nickel-based alloys, which is determined according to the following relationship:
D = (T-800) t1/2 σ1/5 mit T = Temperatur in °K, t = Zeit in h und σ = Spannung in MPa, wobei die Streckgrenze (σo,2) bei Raumtemperatur nach Degradierung in Abhängigkeit von dem besagten Degradations-Parameter (D) ermittelt wird und diese zwecks Eigenschaftsoptimierung einen möglichst hohe Werte aufweisen soll. D = (T-800) t 1/2 σ 1/5 with T = temperature in ° K, t = time in h and σ = stress in MPa, the yield strength (σo, 2 ) at room temperature after degradation depending on the degradation parameter (D) is determined and this should have the highest possible values in order to optimize properties.
PCT/IB2002/004619 2001-11-09 2002-11-05 Method for developing a nickel-base super alloy WO2003040419A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP02779820A EP1451382A1 (en) 2001-11-09 2002-11-05 Method for developing a nickel-base super alloy
US10/838,353 US20040261921A1 (en) 2001-11-09 2004-05-05 Method of developing a nickel-base superalloy

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH2059/01 2001-11-09
CH20592001 2001-11-09

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US10/838,353 Continuation US20040261921A1 (en) 2001-11-09 2004-05-05 Method of developing a nickel-base superalloy

Publications (1)

Publication Number Publication Date
WO2003040419A1 true WO2003040419A1 (en) 2003-05-15

Family

ID=4567342

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2002/004619 WO2003040419A1 (en) 2001-11-09 2002-11-05 Method for developing a nickel-base super alloy

Country Status (4)

Country Link
US (1) US20040261921A1 (en)
EP (1) EP1451382A1 (en)
CN (1) CN100345990C (en)
WO (1) WO2003040419A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113308654A (en) * 2020-02-27 2021-08-27 南京理工大学 Nickel-based alloy with nano structure and gamma' phase composite structure and preparation method thereof

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4449337B2 (en) * 2003-05-09 2010-04-14 株式会社日立製作所 High oxidation resistance Ni-base superalloy castings and gas turbine parts
DE502006003197D1 (en) * 2005-07-12 2009-04-30 Alstom Technology Ltd CERAMIC HEAT INSULATION LAYER
CN100430500C (en) * 2005-11-18 2008-11-05 中国科学院金属研究所 Third nickel-base high-temperature single crystal alloy in low cost
CN100494467C (en) * 2006-08-16 2009-06-03 中国科学院金属研究所 Directional freezing column crystal or single-crystal nickel-base high-temperature alloy repairing or coating method
CN100557092C (en) * 2007-12-17 2009-11-04 北京航空航天大学 Adopt the method for seed crystal method and spiral crystal separation method combined preparation Ni based single-crystal high-temperature alloy
US9347124B2 (en) 2011-11-07 2016-05-24 Siemens Energy, Inc. Hold and cool process for superalloy joining
GB201400352D0 (en) 2014-01-09 2014-02-26 Rolls Royce Plc A nickel based alloy composition
EP3042973B1 (en) 2015-01-07 2017-08-16 Rolls-Royce plc A nickel alloy
US9644504B2 (en) * 2015-03-17 2017-05-09 Caterpillar Inc. Single crystal engine valve
GB2539957B (en) 2015-07-03 2017-12-27 Rolls Royce Plc A nickel-base superalloy
CN112359303B (en) * 2020-11-09 2021-08-24 中南大学 Data-driven nickel-based superalloy strength evaluation method

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0218312A1 (en) * 1985-08-29 1987-04-15 Natsuo Yukawa Alloy phase stability index diagram

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1059712C (en) * 1997-09-26 2000-12-20 冶金工业部钢铁研究总院 Antioxidant nickel-base alloy

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0218312A1 (en) * 1985-08-29 1987-04-15 Natsuo Yukawa Alloy phase stability index diagram

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
DATABASE CA [online] CHEMICAL ABSTRACTS SERVICE, COLUMBUS, OHIO, US; NATHAL, MICHAEL V. ET AL: "Influence of composition on the microstructure and mechanical properties of a nickel-base superalloy single crystal", XP002194791, retrieved from STN Database accession no. 101:96062 CA *
NASA TECH. MEMO. (1984), NAS-TM-83563, E-1942, NAS 1.15:83563, 11 PP. AVAIL.: NTIS FROM: SCI. TECH. AEROSP. REP. 1984, 22(8), ABSTR. NO. N84-17354, 1984 *
SPIEKERMAN P: "Legierungen - ein besonderes patentrechtliches Problem ?", MITTEILUNGEN DER DEUTSCHEN PATENTANWALTE, HEYMANN, KOLN,, DE, 1993, pages 178 - 190, XP002184688, ISSN: 0026-6884 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113308654A (en) * 2020-02-27 2021-08-27 南京理工大学 Nickel-based alloy with nano structure and gamma' phase composite structure and preparation method thereof

Also Published As

Publication number Publication date
CN1585829A (en) 2005-02-23
EP1451382A1 (en) 2004-09-01
CN100345990C (en) 2007-10-31
US20040261921A1 (en) 2004-12-30

Similar Documents

Publication Publication Date Title
EP2402473B1 (en) Process for producing a single-crystal component made of a nickel-based superalloy
DE69903224T2 (en) Monocrystalline nickel-based superalloy with a high gamma prime phase
DE69017625T2 (en) Single-crystalline, nickel-based superalloy.
DE3023576C2 (en)
DE69017574T2 (en) High strength fatigue crack resistant alloy workpiece.
DE69330018T2 (en) HEAT TREATMENT AND METHOD FOR REPAIRING A COBALT-BASED SUPER ALLOY BODY
EP0914484B1 (en) Nickel-base superalloy
DE2749080A1 (en) NICKEL BASED SINGLE CRYSTAL SUPER-ALLOY ARTICLE AND METHOD FOR ITS MANUFACTURING
DE3030962A1 (en) SINGLE AND POLYCRYSTALLINE ALLOY ON NICKEL OR COBALT BASE.
EP2807281B1 (en) Method for producing forged components from a tial alloy and component produced thereby
DE60203562T2 (en) Monocrystalline nickel-based superalloy
EP1451382A1 (en) Method for developing a nickel-base super alloy
DE60125059T2 (en) NICKEL BASE SUPER ALLOY FOR APPLICATION IN HIGH-TEMPERATURE AND HIGH-TEMPERING AREAS
EP1900839B1 (en) Method for the heat treatment of nickel-based superalloys
DE112013003971T5 (en) Nickel-based monocrystalline superalloy
EP1359231B1 (en) Nickel-based superalloy
EP1420075B1 (en) Nickel-base superalloy
EP2196550B1 (en) High temperature and oxidation resistant material on the basis of NiAl
DE69503188T2 (en) Monocrystalline superalloy based on nickel with good corrosion resistance at high temperatures
EP2354261B1 (en) Nickel-Basis-Superalloy with improved degradation behaviour
DE3542882C2 (en)
DE69934158T2 (en) Process and preparation of a directionally solidified nickel-based cast alloy
EP2927336A1 (en) Nickel base alloy with optimised matrix properties
EP3091095A1 (en) Low density rhenium-free nickel base superalloy
EP2451986B2 (en) Nickel base superalloy

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SD SE SG SI SK SL TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LU MC NL PT SE SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2002779820

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 10838353

Country of ref document: US

WWE Wipo information: entry into national phase

Ref document number: 20028222334

Country of ref document: CN

WWP Wipo information: published in national office

Ref document number: 2002779820

Country of ref document: EP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP