EP0087609A1 - Heat resisting nickel-iron alloys for castings with a highly stable structure - Google Patents

Heat resisting nickel-iron alloys for castings with a highly stable structure Download PDF

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EP0087609A1
EP0087609A1 EP83101057A EP83101057A EP0087609A1 EP 0087609 A1 EP0087609 A1 EP 0087609A1 EP 83101057 A EP83101057 A EP 83101057A EP 83101057 A EP83101057 A EP 83101057A EP 0087609 A1 EP0087609 A1 EP 0087609A1
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alloy according
alloy
resistance
castings
nickel
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French (fr)
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EP0087609B1 (en
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Helmut Dr.-Ing. Brandis
Wolfgang Dr.-Ing. Spyra
Josef Reismann
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Thyssen Stahl AG
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Thyssen Edelstahlwerke AG
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C30/00—Alloys containing less than 50% by weight of each constituent
    • 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
    • C22C19/03—Alloys based on nickel or cobalt based on nickel
    • C22C19/05—Alloys based on nickel or cobalt based on nickel with chromium
    • C22C19/051—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W
    • C22C19/055—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W with the maximum Cr content being at least 20% but less than 30%
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S376/00—Induced nuclear reactions: processes, systems, and elements
    • Y10S376/90—Particular material or material shapes for fission reactors

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  • the invention relates to a high-temperature, cobalt-free nickel-iron casting alloy which is insensitive to temperature changes and has great thermodynamic stability of the structural components, which also has high thermal hardness, excellent resistance to oxidation, corrosion and wear, and good welding properties and is particularly suitable as a material for nuclear reactor components.
  • alloys that can be used for example, in the flange area of nuclear reactors, the following limit values are required for certain accompanying elements: Co ⁇ 0.1%, B ⁇ 0.01%, Ta ⁇ 0.002%.
  • Iron-based alloys can generally only be used to a limited extent due to their low heat resistance and lack of corrosion resistance.
  • Nickel-chromium-boron-silicon alloys cannot be considered due to their insufficient toughness and corrosion resistance, so that their advantages, such as a low melting temperature range, cannot be exploited.
  • From DE-PS 27 14 674 is a suitable nickel-based alloy for nuclear reactor components with 0.2 to 1.9% C, 18 to 32% Cr, 1.5 to 8% W, 6 to 12% Mo and optional additives of up to 2% Si, each up to 3% Mn, Nb / Ta, Zr, V and up to 0.9% B, rest 15 to 40% Ni with good cold and warm hardness, good corrosion resistance and friction properties as well as weldability and high fatigue strength .
  • the object of the invention is to propose a structurally stable, heat-resistant nickel-iron cast alloy which, with otherwise the same good properties as that of the aforementioned alloy according to DE-PS 27 14 674, has better scale resistance similar to that of cobalt alloys.
  • the invention differs in a lack of tungsten content and an increased molybdenum content. Tungsten is comparatively more expensive and more uncertainly available than molybdenum. Furthermore, the known alloy can be iron-free or have a maximum content of 59.3% Fe, while in the alloy according to the invention the iron content is narrowly limited at 18 to 26% with a view to achieving the required properties. The same applies to the chromium content, which must be present in amounts of 22 to 26%. Chromium dissolved in the mixed crystal primarily ensures great resistance to oxidation and corrosion, while the chromium bonded in the carbide also determines the wear resistance. For reasons of toughness, the formation of coarse primary carbides was counteracted by the upper limit of the chromium content. Higher chromium levels also deteriorate welding behavior in an unacceptable manner.
  • Molybdenum in amounts of 12.5 to 14.5% in the alloy according to the invention when it is dissolved in the mixed crystal, improves the heat resistance and corrosion resistance and, in the carbide, the wear resistance.
  • DE-PS 27 14 674 does not reveal the knowledge on which the invention is based, that by carefully limiting the mutually influencing elements nickel, iron, chromium and molybdenum, the catastrophic oxidation otherwise frequently observed on materials containing high molybdenum due to the formation of volatile oxides is omitted. It was therefore not foreseeable that by exceeding the maximum content for molybdenum of 12% specified in DE-PS 27 14 674, not only the same but also significantly improved scale resistance can be achieved.
  • the carbon required for carbide formation has to meet a minimum value to achieve good perspiration properties and is limited to a maximum value of 1.6% in order to avoid the formation of coarse primary carbides and to ensure sufficient hardness.
  • the effective carbon content according to the formula is also of particular importance should be between 1.1 and 1.6.
  • the hardness reaches a maximum value with an effective carbon content of approximately 1.3% (FIG. 1).
  • Manganese serves as a deoxidizing and desulfurizing agent, but is limited to a maximum of 0.2% in order to avoid pore formation in the casting or weld metal.
  • Silicon increases the corrosion resistance in acidic reduced solutions and promotes the flow behavior in the liquid phase.
  • Niobium / tantalum is added to refine the grain.
  • the shape of the special carbides is controlled by suitable deoxidizing agents such as calcium, magnesium, aluminum, zirconium and rare earth metals.
  • the structure of the alloy according to the invention consists of primary dendrites with a structure centered on the cubic surface and residual melting neectectic, which is composed of mixed crystals and carbides of the types M 7 C 3 and M 6 C.
  • the alloy according to the invention has a surprisingly high thermodynamic stability between 350 and 600 ° C.
  • Fig. 2 shows this.
  • FIG. 2a shows the structure in 1000 times magnification for the rapidly quenched casting state
  • FIG. 2b shows the structure state after a subsequent 1000-hour annealing at 600 ° C. Changes in structure are imperceptible.
  • the composition of the alloy according to the invention used in the tests shown in FIGS. 1 to 3 (in% by weight) was as follows: The structural stability is confirmed by hardness measurements.
  • the hardness of cast and TIG weld metal was determined between staggered annealing between 350 and 600 ° C. 3 shows the relatively narrow scatter band of hardness with values between 45 and 48 HRC for annealing times up to 1000 h.
  • the hardness is accordingly determined by the primary structure of the alloy according to the invention. Aging processes do not show up to 600 ° C in the course of hardness.
  • the alloy according to the invention was tested with the commercially available cobalt-based alloy, material no. 3177.0 compared.
  • the materials examined had the following composition:
  • FIG. 4 shows that the alloy according to the invention has a superior warm hardness up to at least 900 ° C. compared to the known cobalt alloy.
  • the comparatively large resistance to deformation at high temperature is characteristic of the heat resistance of the alloy according to the invention.
  • the resistance to temperature changes is favorably influenced by a large modulus of elasticity and a small coefficient of expansion (Fig. 5).
  • the nickel alloy according to the invention has a smaller coefficient of expansion and a greater modulus of elasticity than the known cobalt alloy used for comparison.
  • the resistance of the claimed nickel alloy to oxidation is high, as shown in FIG. 6.
  • the oxidation behavior of the new alloy up to 900 ° C is the same as that of the cobalt alloy.
  • the commercially available alloy according to DE-PS 27 14 674 has a tendency to catastrophic oxidation, as can be seen from the sharp increase in oxidation above 800 ° C.
  • a comparison of corrosion values can be found in the following table.
  • the test results show that the nickel alloy according to the invention is superior to the cobalt comparison alloy in terms of resistance to sulfuric acid and hydrochloric acid.
  • the alloy according to the invention is particularly well suited for nuclear reactor components and for armoring valves.

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  • Engineering & Computer Science (AREA)
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Abstract

Die Erfindung betrifft eine hochwarmfeste gegen Temperaturwechsel unempfindliche kobaltfreie Nickel-Eisen-Gußlegierung mit großer thermodynamischer Stabilität der Gefügebestandteile. Sie weist hohe Warmhärte, hervorragende Beständigkeit gegen Oxidation, Korrosion und Verschleiß sowie gute Schweißeigenschaften auf. Die insbesondere als Werkstoff für Kernreaktorbauteile geeignete Legierung besteht aus 1,1 bis 1,6 % C 0,5 bis 1,5 % Si 0,01 bis 0,2 % Mn 22 bis 26 % Cr 12,5 bis 14,5 % Mo 0,2 bis 0,8 % Nb 35 bis 40 % Ni 18 bis 26 % Fe als Ergänzung zu 100 % 0,1 % Co 0,01 % B 0,002 % TaThe invention relates to a heat-resistant cobalt-free nickel-iron cast alloy which is insensitive to temperature changes and has great thermodynamic stability of the structural components. It has high warm hardness, excellent resistance to oxidation, corrosion and wear as well as good welding properties. The alloy, which is particularly suitable as a material for nuclear reactor components, consists of 1.1 to 1.6% C 0.5 to 1.5% Si 0.01 to 0.2% Mn 22 to 26% Cr 12.5 to 14.5% Mo 0.2 to 0.8% Nb 35 to 40% Ni 18 to 26% Fe as a supplement to 100% 0.1% Co 0.01% B 0.002% Ta

Description

Die Erfindung betrifft eine hochwarmfeste, gegen Temperaturwechsel unempfindliche, kobaltfreie Nickel-Eisen-Gußlegierung mit großer thermodynamischer Stabilität der Gefügebestandteile, die zudem hohe Wärmehärte, hervorragende Beständigkeit gegen Oxidation, Korrosion und Verschleiß sowie gute Schweißeigenschaften aufweist und sich insbesondere als Werkstoff für Kernreaktorbauteile eignet.The invention relates to a high-temperature, cobalt-free nickel-iron casting alloy which is insensitive to temperature changes and has great thermodynamic stability of the structural components, which also has high thermal hardness, excellent resistance to oxidation, corrosion and wear, and good welding properties and is particularly suitable as a material for nuclear reactor components.

An Legierungen, die beispielsweise im Flanschbereich von Kernreaktoren einsetzbar sind, werden für bestimmte Begleitelemente folgende Grenzwerte gefordert: Co < 0,1%, B < 0,01%, Ta < 0,002%.For alloys that can be used, for example, in the flange area of nuclear reactors, the following limit values are required for certain accompanying elements: Co <0.1%, B <0.01%, Ta <0.002%.

Eisenbasislegierungen sind in der Regel wegen geringer Warmfestigkeit und mangelnder Korrosionsbeständigkeit nur bedingt verwendbar.Iron-based alloys can generally only be used to a limited extent due to their low heat resistance and lack of corrosion resistance.

Nickel-Chrom-Bor-Silizium-Legierungen kommen wegen ungenügender Zähigkeit und Korrosionsbeständigkeit nicht in Betracht, so daß deren Vorteile, wie niedriger Schmelztemperaturbereich, nicht ausgenutzt werden können.Nickel-chromium-boron-silicon alloys cannot be considered due to their insufficient toughness and corrosion resistance, so that their advantages, such as a low melting temperature range, cannot be exploited.

Aus der DE-PS 27 14 674 ist eine für Kernreaktor-Bauteile geeignete Legierung auf Nickelbasis mit 0,2 bis 1,9% C, 18 bis 32% Cr, 1,5 bis 8% W, 6 bis 12% Mo und Fakultativzusätzen von bis 2% Si, je bis 3% Mn, Nb/Ta, Zr, V und bis 0,9% B, Rest 15 bis 40% Ni mit guter Kalt- und Warmhärte, guter Korrosionsbeständigkeit und Reibeigenschaft sowie Schweißbarkeit und hoher Dauerfestigkeit bekannt.From DE-PS 27 14 674 is a suitable nickel-based alloy for nuclear reactor components with 0.2 to 1.9% C, 18 to 32% Cr, 1.5 to 8% W, 6 to 12% Mo and optional additives of up to 2% Si, each up to 3% Mn, Nb / Ta, Zr, V and up to 0.9% B, rest 15 to 40% Ni with good cold and warm hardness, good corrosion resistance and friction properties as well as weldability and high fatigue strength .

Aufgabe der Erfindung ist es, eine gefügestabile hochwarmfeste Nickel-Eisen-Gußlegierung vorzuschlagen, die bei sonst gleichen guten Eigenschaften wie die der vorerwähnten Legierung gemäß DE-PS 27 14 674 bessere Zunderbeständigkeit ähnlich der von Kobaltlegierungen hat.The object of the invention is to propose a structurally stable, heat-resistant nickel-iron cast alloy which, with otherwise the same good properties as that of the aforementioned alloy according to DE-PS 27 14 674, has better scale resistance similar to that of cobalt alloys.

Zur Lösung dieser Aufgabe wird erfindungsgemäß eine Legierung der in den Ansprüchen gekennzeichneten Zusammensetzung vorgeschlagen. Vorteilhafte Ausgestaltungen sind in den Unteransprüchen gekennzeichnet.To achieve this object, an alloy of the composition characterized in the claims is proposed. Advantageous refinements are characterized in the subclaims.

Von der bekannten Legierung gemäß DE-PS 27 14 674 unterscheidet sich die erfindungsgemäße in einem fehlenden Gehalt an Wolfram und einem erhöhten Gehalt an Molybdän. Wolfram ist vergleichsweise kostenaufwendiger und zudem unsicherer verfügbar als Molybdän. Ferner kann die bekannte Legierung eisenfrei sein bzw. einen Maximalgehalt von 59, 3 % Fe aufweisen, während bei der erfindungsgemäßen Legierung der Eisengehalt mit 18 bis 26 % im Hinblick auf die Erzielung der geforderten Eigenschaften eng begrenzt ist. Das gleiche gilt für den Gehalt an Chrom, das in Mengen von 22 bis 26 % vorzuliegen hat. Im Mischkristall gelöstes Chrom sorgt vornehmlich für große Oxidations- und Korrosionsbeständigkeit , während das im Karbid abgebundene Chrom zusätzlich den Verschleißwiderstand bestimmt. Der Bildung grober Primärkarbide wurde aus Zähigkeitsgründen durch die obere Grenze des Chromgehalts entgegengewirkt. Höhere Chromgehalte verschlechtern außerdem in nicht tragbarer Weise das Schweißverhalten.From the known alloy according to DE-PS 27 14 674, the invention differs in a lack of tungsten content and an increased molybdenum content. Tungsten is comparatively more expensive and more uncertainly available than molybdenum. Furthermore, the known alloy can be iron-free or have a maximum content of 59.3% Fe, while in the alloy according to the invention the iron content is narrowly limited at 18 to 26% with a view to achieving the required properties. The same applies to the chromium content, which must be present in amounts of 22 to 26%. Chromium dissolved in the mixed crystal primarily ensures great resistance to oxidation and corrosion, while the chromium bonded in the carbide also determines the wear resistance. For reasons of toughness, the formation of coarse primary carbides was counteracted by the upper limit of the chromium content. Higher chromium levels also deteriorate welding behavior in an unacceptable manner.

Molybdän in Mengen von 12, 5 bis 14, 5 % verbessert in der erfindungsgemäßen Legierung, wenn es im Mischkristall gelöst ist, die Warmfestigkeit und Korrosionsbeständigkeit und, im Karbid abgebunden, den Verschleißwiderstand. Einen Ersatz des Bildners von Karbid und intermetallischer Phasen Wolfram durch den Bildner nicht unbedingt gleicher Phasen Molybdän lehrt die'DE-PS 27 14 674 nicht, vielmehr geht die bekannte Lehre dahin, einen Mindestgehalt von 1, 5 % Wolfram vorzusehen. Es war auch nicht vorherzusehen, daß bei einem Fehlen von Wolfram in der Legierung die nachfolgend noch näher zu schildernde beträchtliche Verbesserung der Zunderbeständigkeit eintreten würde. Darüber hinaus ist der DE-PS 27 14 674 die der Erfindung zugrunde liegende Erkenntnis nicht zu entnehmen, daß durch sorgfältige Begrenzung der sich gegenseitig beeinflussenden Elemente Nickel, Eisen, Chrom und Molybdän die an hochmolybdänhaltigen Werkstoffen sonst häufig zu beobachtende katastrophale Oxidation durch Entstehen flüchtiger Oxide unterbleibt. Es war also nicht vorherzusehen, daß durch das Überschreiten des in der DE-PS 27 14 674 angegebenen Maximalgehalts für Molybdän von 12 % nicht nur gleiche, sondern wesentlich verbesserte Zunderbeständigkeit erzielt werden kann.Molybdenum in amounts of 12.5 to 14.5% in the alloy according to the invention, when it is dissolved in the mixed crystal, improves the heat resistance and corrosion resistance and, in the carbide, the wear resistance. A replacement of the carbide and intermetallic tungsten phases by the molybdenum, which does not necessarily have the same phases, is not taught by DE-PS 27 14 674, but the known teaching is to provide a minimum content of 1.5% tungsten. It was also not foreseeable that the absence of tungsten in the alloy would result in the considerable improvement in scale resistance, which will be described in more detail below. In addition, DE-PS 27 14 674 does not reveal the knowledge on which the invention is based, that by carefully limiting the mutually influencing elements nickel, iron, chromium and molybdenum, the catastrophic oxidation otherwise frequently observed on materials containing high molybdenum due to the formation of volatile oxides is omitted. It was therefore not foreseeable that by exceeding the maximum content for molybdenum of 12% specified in DE-PS 27 14 674, not only the same but also significantly improved scale resistance can be achieved.

Der zur Karbidbildung benötigte Kohlenstoff hat einem Mindestwert zur Erzielung guter Schweißeigenschaft zu genügen und ist auf einen Höchstwert von 1,6 % begrenzt, um die Bildung grober Primärbcarbide zu vermeiden und um ausreichende Härte zu gewährleisten.The carbon required for carbide formation has to meet a minimum value to achieve good perspiration properties and is limited to a maximum value of 1.6% in order to avoid the formation of coarse primary carbides and to ensure sufficient hardness.

Von besonderer Bedeutung ist auch der effektive Kohlenstoffgehalt, der nach der Formel

Figure imgb0001
zwischen 1,1 und 1,6 liegen soll. Dabei erreicht die Härte bei einem effektiven Kohlenstoffgehalt von etwa 1,3% einen Größtwert (Fig. 1).The effective carbon content according to the formula is also of particular importance
Figure imgb0001
 should be between 1.1 and 1.6. The hardness reaches a maximum value with an effective carbon content of approximately 1.3% (FIG. 1).

Mangan dient als Desoxidations- und Entschwefelungsmittel, ist jedoch begrenzt auf maximal 0, 2 %,um Porenbildung im Guß oder Schweißgut zu vermeiden.Manganese serves as a deoxidizing and desulfurizing agent, but is limited to a maximum of 0.2% in order to avoid pore formation in the casting or weld metal.

Silizium erhöht die Korrosionsbeständigkeit in sauren reduzierten Lösungen und begünstigt das Fließverhalten in flüssiger Phase.Silicon increases the corrosion resistance in acidic reduced solutions and promotes the flow behavior in the liquid phase.

Niob/Tantal wird zur Kornverfeinerung zugesetzt.Niobium / tantalum is added to refine the grain.

Durch geeignete Desoxidationsmittel wie Kalzium, Magnesium, Aluminium, Zirkonium und seltene Erdmetalle wird die Form der Sonderkarbide gesteuert.The shape of the special carbides is controlled by suitable deoxidizing agents such as calcium, magnesium, aluminum, zirconium and rare earth metals.

Das Gefüge der erfindungsgemäßen Legierung besteht nach metallografischer und röntgenografischer Untersuchung aus Primärdendriten mit kubischflächenzentrierter Struktur und Restschmelzneutektikum, das sich aus Mischkristall und Karbiden vom Typ M7C3 sowie M6C zusammensetzt..According to metallographic and X-ray examination, the structure of the alloy according to the invention consists of primary dendrites with a structure centered on the cubic surface and residual melting neectectic, which is composed of mixed crystals and carbides of the types M 7 C 3 and M 6 C.

Zwischen 350 und 600° C weist die erfindungsgemäße Legierung eine überraschend hohe thermodynamische Stabilität auf. Fig. 2 belegt dies. Fig. 2a zeigt das Gefüge in 1000-facher Vergrößerung für den schnell abgeschreckten Gußzustand, während Fig. 2b den Gefügezustand nach eine anschließenden 1000h-Glühung bei 600° C zeigt. Gefügeänderungen sind nicht wahrnehmbar. Die Zusammensetzung der bei den in den Figuren 1 bis 3 wiedergegebenen Versuchen eingesetzten erfindungsgemäßen Legierung (in Gew.-%) war wie folgt:

Figure imgb0002
Die Gefügestabilität wird durch Härtemessungen bestätigt. Da im Flanschbereich von Kernreaktoren die Anwendungstemperaturen bei 350° C und im Störfalle zeitweise sogar bei 500° C liegen, wurde die Härte an Guß- und WIG-Schweißgut nach zeitlich gestaffelten Glühungen zwischen 350 und 600° C ermittelt. Fig. 3 zeigt das relativ schmale Streuband der Härte mit Werten zwischen 45 und 48 HRC für Glühzeiten bis 1000 h. Die Härte wird demnach durch das Primärgefüge der erfindungsgemäßen Legierung bestimmt. Überalterungsvorgänge deuten sich bis 600° C im Härteverlauf nicht an.The alloy according to the invention has a surprisingly high thermodynamic stability between 350 and 600 ° C. Fig. 2 shows this. FIG. 2a shows the structure in 1000 times magnification for the rapidly quenched casting state, while FIG. 2b shows the structure state after a subsequent 1000-hour annealing at 600 ° C. Changes in structure are imperceptible. The composition of the alloy according to the invention used in the tests shown in FIGS. 1 to 3 (in% by weight) was as follows:
Figure imgb0002
 The structural stability is confirmed by hardness measurements. Since the application temperatures in the flange area of nuclear reactors are 350 ° C and sometimes even 500 ° C in the event of a malfunction, the hardness of cast and TIG weld metal was determined between staggered annealing between 350 and 600 ° C. 3 shows the relatively narrow scatter band of hardness with values between 45 and 48 HRC for annealing times up to 1000 h. The hardness is accordingly determined by the primary structure of the alloy according to the invention. Aging processes do not show up to 600 ° C in the course of hardness.

In weiteren Untersuchungen wurde die erfindungsgemäße Legierung mit der handelsüblichen Kobaltbasislegierung, Werkstoff-Nr. 3177.0 verglichen. Die untersuchten Werkstoffe hatten folgende Zusammensetzung:

Figure imgb0003
In further investigations, the alloy according to the invention was tested with the commercially available cobalt-based alloy, material no. 3177.0 compared. The materials examined had the following composition:
Figure imgb0003

Fig. 4 zeigt, daß die erfindungsgemäße Legierung gegenüber der bekannten Kobaltlegierung bis mindestens 900°C eine überlegene Warmhärte aufweist. Der vergleichsweise große Formänderungswiderstand bei hoher Temperatur ist kennzeichnend für die Warmfestigkeit der erfindungsgemäßen Legierung.FIG. 4 shows that the alloy according to the invention has a superior warm hardness up to at least 900 ° C. compared to the known cobalt alloy. The comparatively large resistance to deformation at high temperature is characteristic of the heat resistance of the alloy according to the invention.

Die Temperaturwechselbeständigkeit wird günstig beeinflußt durch großen Elastizitätsmodul und kleinen Ausdehnungskoeffizienten (Fig. 5), Im gesamten untersuchten Temperaturbereich bis 900°C weist die erfindungsgemäße Nickellegierung einen kleineren Ausdehnungskoeffizienten und einen größeren Elastizitätsmodul auf als die zum Vergleich herangezogene bekannte.Kobaltlegierung.The resistance to temperature changes is favorably influenced by a large modulus of elasticity and a small coefficient of expansion (Fig. 5). In the entire temperature range examined up to 900 ° C, the nickel alloy according to the invention has a smaller coefficient of expansion and a greater modulus of elasticity than the known cobalt alloy used for comparison.

Der Widerstand der beanspruchten Nickellegierung gegenüber Oxidation (Zunderbeständigkeit) ist gemäß Fig. 6 groß. Das Oxidationsverhalten der neuen Legierung bis 900°C ist mit dem der Kobaltlegierung gleich. Demgegenüber weist die handelsübliche Legierung gemäß DE-PS 27 14 674 Neigung zur katastrophal Oxidation auf, wie aus dem starken Anstieg der Oxidation oberhalb von 800°C hervorgeht.The resistance of the claimed nickel alloy to oxidation (scale resistance) is high, as shown in FIG. 6. The oxidation behavior of the new alloy up to 900 ° C is the same as that of the cobalt alloy. In contrast, the commercially available alloy according to DE-PS 27 14 674 has a tendency to catastrophic oxidation, as can be seen from the sharp increase in oxidation above 800 ° C.

Eine Gegenüberstellung von Korrosionswerten ist der folgenden Tabelle zu entnehmen. Die Prüfergebnisse zeigen, daß die erfindungsgemäße Nickellegierung der Kobalt-Vergleichslegierung überlegen ist im Widerstand gegenüber Schwefelsäure und Salzsäure.

Figure imgb0004
A comparison of corrosion values can be found in the following table. The test results show that the nickel alloy according to the invention is superior to the cobalt comparison alloy in terms of resistance to sulfuric acid and hydrochloric acid.
Figure imgb0004

Aufgrund ihrer Eigenschaftskombination, insbesondere von Warmhärte, Korrosions- und Zunderbeständigkeit eignet sich die erfindungsgemäße Legierung besonders gut für Kernreaktorbauteile und zum Panzern von Ventilen.Due to its combination of properties, in particular of warm hardness, corrosion and scale resistance, the alloy according to the invention is particularly well suited for nuclear reactor components and for armoring valves.

Claims (6)

1.Hochwarmfeste gegen Temperaturwechsel unempfindliche kobaltfreie Nickel-Eisen-Gußlegierung mit großer thermodynamischer Stabilität der Gefügebestandteile, die zudem hohe Warmehärte, hervorragende Beständigkeit gegen Oxidation, Korrosion und Verschleiß sowie gute Schweißeigenschaften aufweist und sich insbesondere als Werkstoff für Kernreaktorbauteile eignet, bestehend aus 1, 1 bis 1,6 %C 0,5 bis 1,5 % Si 0,01 bis 0,2 % Mn 22 bis 26 % Cr 12,5 bis 14,5 % Mo 0,2 bis 0,8 %Nb 35 bis 40 % Ni 18 bis 26 % Fe 0, 1 % Co 0,01 % B 0,002 % Ta. 1.High-temperature resistant cobalt-free nickel-iron casting alloy insensitive to temperature changes with great thermodynamic stability of the structural components, which also has high heat hardness, excellent resistance to oxidation, corrosion and wear as well as good welding properties and is particularly suitable as a material for nuclear reactor components consisting of 1.1 to 1.6% C 0.5 to 1.5% Si 0.01 to 0.2% Mn 22 to 26% Cr 12.5 to 14.5% Mo 0.2 to 0.8% Nb 35 to 40% Ni 18 to 26% Fe 0.1% Co 0.01% B 0.002% Ta. 2. Legierung nach Anspruch 1 gekennzeichnet durch 1,25 bis 1, 55 % C 0,8 bis 1,30 % Si 0,02 bis 0, 15 % Mn 24 bis 26 % Cr 12,5 bis 13,5 % Mo 0, 3 bis 0, 7 % Nb 35 bis 37,5 % Ni 19 bis 26 % Fe < 0, % Co 0,01 % B 0,002 % Ta 2. Alloy according to claim 1 characterized by 1.25 to 1.55% C 0.8 to 1.30% Si 0.02 to 0.15% Mn 24 to 26% Cr 12.5 to 13.5% Mo 0.3 to 0.7% Nb 35 to 37.5% Ni 19 to 26% Fe <0.% Co 0.01% B 0.002% Ta 3. Legierung nach Anspruch 1 mit der Maßgabe, daß
Figure imgb0005
 für % Ceff = % C + 0, 86 · %N + 1,11 % B ist. 3. Alloy according to claim 1 with the proviso that
Figure imgb0005
 for% C eff =% C + 0.86% N + 1.11% B. 4. Legierung nach Anspruch 2 mit der Maßgabe, daß
Figure imgb0006
für % Ceff = %C + 0,86 ˙ % N + 1,11 ˙ %B ist.4. Alloy according to claim 2 with the proviso that
Figure imgb0006
 for% C eff =% C + 0.86 ˙% N + 1.11 ˙% B. 5. Verwendung der Legierung nach Ansprüchen 1 bis 4 als Werkstoff fürKernreaktor-BauteileUse of the alloy according to claims 1 to 4 as a material for nuclear reactor components 6. Verwendung der Legierung nach Ansprüchen 1 bis 4 als Werkstoff zum Panzern von Verschleißteilen, wie Ventilen, Heißdampfarmaturen, Kettensägen.6. Use of the alloy according to claims 1 to 4 as a material for armoring wearing parts, such as valves, superheated steam fittings, chainsaws.
EP83101057A 1982-02-27 1983-02-04 Heat resisting nickel-iron alloys for castings with a highly stable structure Expired EP0087609B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3207162A DE3207162C1 (en) 1982-02-27 1982-02-27 Highly heat-resistant cast nickel-iron alloy with great structural stability
DE3207162 1982-02-27

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EP0087609A1 true EP0087609A1 (en) 1983-09-07
EP0087609B1 EP0087609B1 (en) 1985-09-25

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EP (1) EP0087609B1 (en)
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US8297046B2 (en) 2003-01-02 2012-10-30 Daimler Ag Exhaust gas aftertreatment installation and method

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Publication number Priority date Publication date Assignee Title
US4547338A (en) * 1984-12-14 1985-10-15 Amax Inc. Fe-Ni-Cr corrosion resistant alloy
US8613886B2 (en) * 2006-06-29 2013-12-24 L. E. Jones Company Nickel-rich wear resistant alloy and method of making and use thereof

Citations (4)

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Publication number Priority date Publication date Assignee Title
GB647701A (en) * 1944-02-24 1950-12-20 William Jessop And Sons Ltd Improvements in and relating to nickel chromium steels
GB670555A (en) * 1946-04-12 1952-04-23 Jessop William & Sons Ltd Improvements in or relating to nickel-chromium steels
FR2129518A5 (en) * 1971-03-09 1972-10-27 Kobe Steel Ltd
FR2346462A1 (en) * 1976-04-02 1977-10-28 Commissariat Energie Atomique HIGH ENDURANCE SUPER ALLOY WITHOUT COBALT APPLICABLE ESPECIALLY IN THE NUCLEAR INDUSTRY

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JPS5517403A (en) * 1978-07-24 1980-02-06 Hitachi Ltd Sliding mechanism for control rod

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Publication number Priority date Publication date Assignee Title
GB647701A (en) * 1944-02-24 1950-12-20 William Jessop And Sons Ltd Improvements in and relating to nickel chromium steels
GB670555A (en) * 1946-04-12 1952-04-23 Jessop William & Sons Ltd Improvements in or relating to nickel-chromium steels
FR2129518A5 (en) * 1971-03-09 1972-10-27 Kobe Steel Ltd
FR2346462A1 (en) * 1976-04-02 1977-10-28 Commissariat Energie Atomique HIGH ENDURANCE SUPER ALLOY WITHOUT COBALT APPLICABLE ESPECIALLY IN THE NUCLEAR INDUSTRY

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8297046B2 (en) 2003-01-02 2012-10-30 Daimler Ag Exhaust gas aftertreatment installation and method
US9057307B2 (en) 2003-01-02 2015-06-16 Daimler Ag Exhaust gas aftertreatment installation and method

Also Published As

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US4464335A (en) 1984-08-07
EP0087609B1 (en) 1985-09-25
DE3207162C1 (en) 1983-10-06
CA1208043A (en) 1986-07-22

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