EP0410979B1 - Hardenable nickel alloy - Google Patents

Hardenable nickel alloy Download PDF

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Publication number
EP0410979B1
EP0410979B1 EP89903692A EP89903692A EP0410979B1 EP 0410979 B1 EP0410979 B1 EP 0410979B1 EP 89903692 A EP89903692 A EP 89903692A EP 89903692 A EP89903692 A EP 89903692A EP 0410979 B1 EP0410979 B1 EP 0410979B1
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EP
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Prior art keywords
nickel
components
alloy
quenched
bis
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German (de)
French (fr)
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EP0410979A1 (en
Inventor
Ulrich Heubner
Michael KÖHLER
Gregory B. Chitwood
Jon R. Bryant
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Krupp VDM GmbH
Otis Engineering Corp
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VDM Nickel Technologie AG
Krupp VDM GmbH
Otis Engineering Corp
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    • 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%
    • 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
    • C22C19/056—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W with the maximum Cr content being at least 10% but less than 20%
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/10—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of nickel or cobalt or alloys based thereon

Definitions

  • the invention relates to the use of a hardenable nickel alloy with a 0.2% proof stress of at least 500 N / mm 2 and very good corrosion resistance under acid gas conditions and to a method for producing such components.
  • Very good corrosion resistance means that the alloy and parts made from it can be exposed at temperatures between room temperature and 350 ° C and pressures between 10 and 100 bar solutions containing C0 2 , H 2 S, chlorides and free sulfur.
  • J.A. Harris, T.F. Lemke, D.F. Smith and R.H. Moeller presented a hardenable nickel-based material with (% by weight) 42 nickel, 21 chromium, 3 molybdenum, 2.2 copper, 2.1 titanium, 0.3 aluminum, 0.02 carbon, the rest iron (The Development of a Corrosion Resistant Alloy for Sour Gas Service, CORROSION 84, Paper No.216, National Association of Corrosion Engineers, Houston, Texas, 1984), which is said to be stable under sour gas conditions. The results reported, however, show that under extreme corrosion conditions, such as those that can occur at greater depths, the material presented is destroyed by stress corrosion cracking.
  • the nickel alloy is particularly suitable as a material for the production of components that are to be used under very aggressive sour gas conditions.
  • Cast blocks were made, the cast blocks were homogenized at 1220 ° C and then thermoformed above 1000 ° C and the parts obtained were quenched in water, and the thermoformed and quenched parts were cured at 650 to 750 ° C for 4 to 16 hours and then subjected to air cooling.
  • the mechanical-technological properties can be further improved by additional curing steps.
  • the thermoformed and quenched parts are first annealed for 4 to 10 hours at 700 ° C to 750 ° C, then cooled in an oven at 5 to 25 ° C per hour by 150 ° C and then placed in air.
  • the components can also be kept between 730 ° C to 750 ° C for 30 minutes, then cooled in an oven at 5 to 25 ° C per hour to 700 ° C and then at 2 to 15 ° C per hour to 580 ° C. Finally, the components are placed in air.
  • thermoformed parts are subjected to solution annealing at 1150 to 1190 ° C. before quenching in water.
  • thermoformed, solution-annealed and water-quenched parts can also be kept at 700 to 750 ° C for 4 to 10 hours, then in the furnace at 5 to 25 ° C per hour by 150 ° C and finally further cooled in air.
  • Table 1 shows the chemical composition of 7 alloys, which - after different heat treatment - have been examined for their mechanical properties at room temperature (RT) and at 260 ° C. The results are summarized in Tables 2 to 7.
  • results show that the required minimum mechanical properties were achieved in all cases and in some cases considerably exceeded. Furthermore, it can be seen from the results as a whole that different values of the mechanical properties can be achieved with the different variants of the heat treatment, which can be advantageous for the adjustment to special requirement profiles. In favor of higher elongation at break values, for example, maximum strength values can be dispensed with and vice versa. Apart from this general tendency, it can also be seen that the highest strength values are achieved if the thermoformed parts are not solution annealed again, but are directly quenched in water and that the maximum achievable strength depends on the total aluminum plus titanium content.
  • the aluminum and titanium contents cannot be increased arbitrarily, because disadvantageous precipitation phases then occur which cannot be avoided or compensated for even with complex heat treatment.
  • the numerous alternatives in the heat treatment it is always possible to achieve optimum strength values in each case without having to put up with disadvantageous microstructures.
  • the more complex three-stage curing treatment will be indicated when it comes to avoiding a decrease in the impact strength when setting the highest possible strength values.
  • the alloy according to the invention accordingly shows in a novel way a combination of high strength not yet achieved with curable materials and at the same time excellent resistance in very aggressive sour gas media.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Manufacture And Refinement Of Metals (AREA)
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  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

A hardenable nickel alloy has a yield strength of at least 500 N/mm2 and a high corrosion resistance in very aggressive acid gas media. The alloy consists of 43 to 51 % nickel, 19 to 24 % chromium, 4.5 to 7.5 % molybdenum, 0.4 to 2.5 % copper, 0.3 to 1.8 % aluminium and 0.9 to 2.2 % titanium, the remainder being iron. Also described are processes for heat-treatment of the alloy which ensure high strength together with good ductility.

Description

Die Erfindung bezieht sich auf die Verwendung einer aushärtbaren Nickellegierung mit einer 0,2 %-Dehngrenze von mindestens 500 N/mm2 und unter Sauergas-Bedingungen sehr guter Korrosionsbeständigkeit und auf ein Verfahren zur Herstellung solcher Bauteile.The invention relates to the use of a hardenable nickel alloy with a 0.2% proof stress of at least 500 N / mm 2 and very good corrosion resistance under acid gas conditions and to a method for producing such components.

Sehr gute Korrosionsbeständigkeit bedeutet, daß die Legierung und daraus hergestellte Teile bei Temperaturen zwischen Raumtemperatur und 350 ° C und Drücken zwischen 10 und 100 bar Lösungen ausgesetzt werden können, die C02, H2S, Chloride und freien Schwefel enthalten.Very good corrosion resistance means that the alloy and parts made from it can be exposed at temperatures between room temperature and 350 ° C and pressures between 10 and 100 bar solutions containing C0 2 , H 2 S, chlorides and free sulfur.

Solche Bedingungen sind typisch für die Erdöl- und Erdgas-Suche und -Förderung. Zur Herstellung von Bauteilen, die diesen Bedingungen genügen, sind bisher hoch mit Chrom und Molybdän legierte Nickelbasiswerkstoffe verwendet worden, obwohl deren 0,2 %-Dehngrenze nur bei 310 bis 345 N/mm2 liegt. Durch Kaltumformen kann deren Festigkeit erhöht werden, wobei aber gleichzeitig eine Verringerung der Duktilität toleriert werden muß. Außerdem ist eine Kaltverfestigung bei größeren Querschnitten im allgemeinen nicht mehr anwendbar, so daß in solchen Fällen auf aushärtbare Werkstoffe zurückgegriffen werden muß. Werkstoffe, bei denen durch Aushärten höhere Festigkeiten erzielt werden können, besitzen unter sehr aggressiven Sauergas-Bedingungen aber keine ausreichende Korrosionsbeständigkeit, oder sie enthalten Niob als wesentliches zur Aushärtung erforderliches Legierungselement.Such conditions are typical of oil and gas exploration and production. To date, nickel-base materials with a high chromium and molybdenum alloy have been used to produce components that meet these conditions, although their 0.2% proof stress is only between 310 and 345 N / mm 2 . Cold forming can increase their strength, but a reduction in ductility must be tolerated at the same time. In addition, strain hardening is generally no longer applicable for larger cross sections, so that in such cases it is necessary to use curable materials. However, materials in which higher strengths can be achieved by hardening do not have sufficient corrosion resistance under very aggressive sour gas conditions, or they contain niobium as an essential alloying element required for hardening.

Beispielsweise wurde von J.A. Harris, T.F. Lemke, D.F. Smith und R.H. Moeller ein aushärtbarer Nickelbasiswerkstoff mit (Gew.-%) 42 Nickel, 21 Chrom, 3 Molybdän, 2,2 Kupfer, 2,1 Titan, 0,3 Aluminium, 0,02 Kohlenstoff, Rest Eisen vorgestellt (The Development of a Corrosion Resistant Alloy for Sour Gas Service, CORROSION 84, Paper No.216, National Association of Corrosion Engineers, Houston, Texas, 1984), der unter Sauergas-Bedingungen beständig sein soll. Die mitgeteilten Ergebnisse zeigen jedoch, daß unter extremen Korrosionsbedingungen, wie sie in größeren Tiefen herrschen können, der vorgestellte Werkstoff durch Spannungsrißkorrosion zerstört wird.For example, J.A. Harris, T.F. Lemke, D.F. Smith and R.H. Moeller presented a hardenable nickel-based material with (% by weight) 42 nickel, 21 chromium, 3 molybdenum, 2.2 copper, 2.1 titanium, 0.3 aluminum, 0.02 carbon, the rest iron (The Development of a Corrosion Resistant Alloy for Sour Gas Service, CORROSION 84, Paper No.216, National Association of Corrosion Engineers, Houston, Texas, 1984), which is said to be stable under sour gas conditions. The results reported, however, show that under extreme corrosion conditions, such as those that can occur at greater depths, the material presented is destroyed by stress corrosion cracking.

Ein anderer Legierungsvorschlag ist mit der European Patent Specification 0 066 361 vorgestellt worden. Dieser Legierungsvorschlag mit (Gew.%) 45 bis 55 Nickel, 15 bis 22 Chrom, 6 bis 9 Molybdän, 2,5 bis 5,5 Niob, 1 bis 2 Titan, bis zu 1 Aluminium, bis zu 0,35 Kohlenstoff und 10 bis 28 Eisen sowie weiteren Begleitelementen enthält Niob als eine für die Aushärtung wesentliche Legierungskomponente. Niobhaltige Legierungen sind für eine großtechnische Herstellung und Verarbeitung aber weitaus weniger gut geeignet als niobfreie, da niobhaltige Schrotte und Fabrikationsabfälle zum Wiedereinschmelzen einen Vakuuminduktionsofen erforderlich machen, wenn beträchtliche Verluste dieses teuren Legierungselements durch Abbrand vermieden werden sollen. Außerdem schränken höhere Niobgehalte, wie sie hier vorgeschlagen sind, die Warmformgebungsmöglichkeiten sehr deutlich ein. Solche Nachteile treffen auch zu auf die von R.B. Frank und T.A. DeBold vorgestellte Legierung mit (Gew.%) 59 bis 63 Nickel, 19 bis 22 Chrom, 7 bis 9,5 Molybdän, 2,75 bis 4 Niob, 1 bis 1,6 Titan, max. 0,35 Aluminium, max. 0,03 Kohlenstoff, Rest Eisen (Properties of an Age-Hardenable, Corrosion-Resistant, Nickel-Base Alloy, CORROSION 88, Paper No.75, National Association of Corrosion Engineers, Houston, Texas, 1988). Von dieser Legierung ist darüber hinaus infolge ihres hohen Nickelgehaltes, eine ausgeprägte Neigung zur Wasserstoffversprödung unter Sauergasbedingungen im Temperaturbereich unter etwa 100°C zu erwarten, und in dieser Hinsicht demgemäß eine eingeschränkte Verwendungsfähigkeit.Another alloy proposal has been presented with European Patent Specification 0 066 361. This alloy proposal with (% by weight) 45 to 55 nickel, 15 to 22 chromium, 6 to 9 molybdenum, 2.5 to 5.5 niobium, 1 to 2 titanium, up to 1 aluminum, up to 0.35 carbon and 10 Up to 28 irons and other accompanying elements contain niobium as an alloy component essential for hardening. However, niobium-containing alloys are much less suitable for large-scale production and processing than niobium-free ones, since niobium-containing scrap and manufacturing waste require a vacuum induction furnace for remelting if considerable losses of this expensive alloying element are to be avoided by burning. In addition, higher levels of niobium, as proposed here, restrict the thermoforming options very clearly. Such disadvantages also apply to the alloy presented by RB Frank and TA DeBold with (% by weight) 59 to 63 nickel, 19 to 22 chromium, 7 to 9.5 molybdenum, 2.75 to 4 niobium, 1 to 1.6 Titanium, max. 0.35 aluminum, max. 0.03 carbon, balance iron (Properties of an Age-Hardenable, Corrosion-Resistant, Nickel-Base Alloy, CORROSION 88, Paper No.75, National Association of Corrosion Engineers, Houston, Texas, 1988). In addition, due to its high nickel content, this alloy can be expected to have a pronounced tendency towards hydrogen embrittlement under sour gas conditions in the temperature range below approximately 100 ° C., and is therefore of limited use in this regard.

Die aus der GB-A-531466 bekannte Stahllegierung mit 25 bis 50 % Nickel, wobei Nickel ganz oder teilweise durch Kobalt ersetzt sein kann, 15 bis 30 % Chrom, 2,5 bis 5 % Molybdän, bis 2 % Kupfer, bis 2 % Mangan, bis 2 % Silizium, bis 0,3 % Kohlenstoff, bis 2 % Aluminium, bis 2 % Vanadium, bis 1 % Uran, 0,1 bis 1,5 % Titan, Rest Eisen ist in ihrer Zusammensetzung so ausgelegt, daß gute Warmfestigkeitseigenschaften erreicht werden und eine ausreichende Beständigkeit gegen Lochfraßkorrosion gegeben ist.The steel alloy known from GB-A-531466 with 25 to 50% nickel, where nickel can be replaced in whole or in part by cobalt, 15 to 30% chromium, 2.5 to 5% molybdenum, up to 2% copper, up to 2% Manganese, up to 2% silicon, up to 0.3% carbon, up to 2% aluminum, up to 2% vanadium, up to 1% uranium, 0.1 to 1.5% titanium, the rest of iron is designed in such a way that good Heat resistance properties are achieved and there is sufficient resistance to pitting corrosion.

Es besteht somit die Aufgabe, einen aushärtbaren Werkstoff vorzuschlagen, der allen genannten Bedingungen entspricht, d.h., der die geforderten Festigkeitswerte besitzt, unter sehr aggressiven Sauergas- Bedingungen eine ausreichende Korrosionsbeständigkeit aufweist und der kein Niob zur Aushärtung benötigt.It is therefore the task to propose a curable material that meets all the conditions mentioned, i.e. that has the required strength values, has sufficient corrosion resistance under very aggressive sour gas conditions and that does not require niobium for curing.

Zur Lösung diesr Aufgabe wird die Verwendung einer aushärtbaren Nickellegierung vorgeschlagen, die gekennzeichnet ist durch

  • 43 bis 51 % Nickel
  • 19 bis 24 % Chrom
  • 5 bis 7,5 % Molybdän
  • 0,4 bis 2,5 % Kupfer
  • bis 1 % Mangan
  • bis 0,5 % Silizium
  • bis 0,02 % Kohlenstoff
  • bis 2 % Kobalt
  • 0,3 bis 1,8 % Aluminium
  • 0,9 bis 2,2 % Titan
    • Rest Eisen, einschl. unvermeidbarer,
    • herstellungsbedingter Verunreinigungen

Die erfindungsgemäße Nickellegierung ist geeignet als Werkstoff zur Herstellung von Bauteilen, die eine 0,2 %-Dehngrenze von mindestens 500 N/mm2, eine Gleichmaßdehnung A5 von mindestens 20 %, eine Brucheinschnürung von mindestens 25 % und bei Raumtemperatur eine Kerbschlagarbeit von mindestens 54 J entsprechend mindestens 40 ft Ibs an ISO-V-Proben aufweisen müssen.To solve this problem, the use of a hardenable nickel alloy, which is characterized by
  • 43 to 51% nickel
  • 19 to 24% chromium
  • 5 to 7.5% molybdenum
  • 0.4 to 2.5% copper
  • up to 1% manganese
  • up to 0.5% silicon
  • up to 0.02% carbon
  • up to 2% cobalt
  • 0.3 to 1.8% aluminum
  • 0.9 to 2.2% titanium
    • Rest of iron, including inevitable
    • manufacturing-related impurities

The nickel alloy according to the invention is suitable as a material for the production of components which have a 0.2% proof stress of at least 500 N / mm 2 , a uniform elongation A 5 of at least 20%, a constriction of fracture of at least 25% and a notch impact energy of at least at room temperature 54 J must have at least 40 ft Ibs of ISO-V samples.

Eine eingeschränkte Zusammensetzung, die sich durch besonders gute Verarbeitungseigenschaften auszeichnet, ist gekennzeichnet durch

  • 46 bis 51 % Nickel,
  • 20 bis 23,5 % Chrom,
  • 5 bis 7 % Molybdän,
  • 1,5 bis 2,2 % Kupfer,
  • bis 0,8 % Mangan,
  • bis 0,1 % Silizium,
  • bis 0,015% Kohlenstoff,
  • bis 2 % Kobalt
  • 0,4 bis 0,9 % Aluminium,
  • 1,5 bis 2,1 % Titan,
    • Rest Eisen, einschließlich unvermeidbarer,
    • herstellungsbedingter Verunreinigungen.
A restricted composition, which is characterized by particularly good processing properties, is characterized by
  • 46 to 51% nickel,
  • 20 to 23.5% chromium,
  • 5 to 7% molybdenum,
  • 1.5 to 2.2% copper,
  • up to 0.8% manganese,
  • up to 0.1% silicon,
  • up to 0.015% carbon,
  • up to 2% cobalt
  • 0.4 to 0.9% aluminum,
  • 1.5 to 2.1% titanium,
    • Rest of iron, including unavoidable,
    • manufacturing-related impurities.

Diese kann verwendet werden, wenn eine 0,2 %-Dehngrenze von mindestens 750 N/mm2 gefordert wird, sowie eine Gleichmaßdehnung A5 von mindestens 20 %, eine Brucheinschnürung von mindestens 25 % und bei Raumtemperatur eine Kerbschlagarbeit von mindestens 54 J entsprechend mindestens 40 ft Ibs an ISO-V-Proben.This can be used if a 0.2% proof stress of at least 750 N / mm 2 is required, as well as a uniform elongation A 5 of at least 20%, a constriction of fracture of at least 25% and a notch impact energy of at least 54 J at room temperature 40 ft Ibs of ISO V samples.

Die Nickellegierung ist insbesondere geeignet als Werkstoff zur Herstellung von Bauteilen, die unter sehr aggressiven Sauergas-Bedingungen eingesetzt werden sollen.The nickel alloy is particularly suitable as a material for the production of components that are to be used under very aggressive sour gas conditions.

Bei der Herstellung von Bauteilen, die eine ausreichende Korrosionsbeständigkeit unter sehr aggressiven Sauergas-Bedingungen und eine 0,2 %-Dehngrenze von mindestens 500 N/mm2 aufweisen müssen, geht man zweckmäßigerweise so vor, daß aus einer Legierung mit

  • 43 bis 51 % Nickel
  • 19 bis 24 % Chrom
  • 5 bis 7,5 % Molybdän
  • 0,4 bis 2,5 % Kupfer
  • bis 1 % Mangan
  • bis 0,5 % Silizium
  • bis 0,02 % Kohlenstoff
  • bis 2 % Kobalt
  • 0,3 bis 1,8 % Aluminium
  • 0,9 bis 2,2 % Titan
    • Rest Eisen, einschl. unvermeidbarer,
    • herstellungsbedingter Verunreinigungen
In the manufacture of components which must have sufficient corrosion resistance under very aggressive sour gas conditions and a 0.2% proof stress of at least 500 N / mm 2 , it is expedient to proceed in such a way that an alloy with
  • 43 to 51% nickel
  • 19 to 24% chromium
  • 5 to 7.5% molybdenum
  • 0.4 to 2.5% copper
  • up to 1% manganese
  • up to 0.5% silicon
  • up to 0.02% carbon
  • up to 2% cobalt
  • 0.3 to 1.8% aluminum
  • 0.9 to 2.2% titanium
    • Rest of iron, including inevitable
    • manufacturing-related impurities

Gußblöcke gefertigt, die Gußblöcke bei 1220° C homogenisiert und danach oberhalb von 1000 °C warmverformt und die erhaltenen Teile in Wasser abgeschreckt, sowie die warmgeformten und abgeschreckten Teile 4 bis 16 Stunden bei 650 bis 750 °C ausgehärtet und danach einer Luftabkühlung unterworfen werden.Cast blocks were made, the cast blocks were homogenized at 1220 ° C and then thermoformed above 1000 ° C and the parts obtained were quenched in water, and the thermoformed and quenched parts were cured at 650 to 750 ° C for 4 to 16 hours and then subjected to air cooling.

Für Gußblöcke, die besonders gute Verarbeitungseigenschaften besitzen sollen, wird vorzugsweise die folgende Legierung mit

  • 46 bis 51 % Nickel,
  • 20 bis 23,5 % Chrom,
  • 5 bis 7 % Molybdän,
  • 1,5 bis 2,2 % Kupfer,
  • bis 0,8 % Mangan,
  • bis 0,1 % Silizium,
  • bis 0,015% Kohlenstoff,
  • bis 2 % Kobalt
  • 0,4 bis 0,9 % Aluminium,
  • 1,5 bis 2,1 % Titan,
    • Rest Eisen, einschließlich unvermeidbarer,
    • herstellungsbedingter Verunreinigungen verwendet.
The following alloy is preferably used for casting blocks which are said to have particularly good processing properties
  • 46 to 51% nickel,
  • 20 to 23.5% chromium,
  • 5 to 7% molybdenum,
  • 1.5 to 2.2% copper,
  • up to 0.8% manganese,
  • up to 0.1% silicon,
  • up to 0.015% carbon,
  • up to 2% cobalt
  • 0.4 to 0.9% aluminum,
  • 1.5 to 2.1% titanium,
    • Rest of iron, including unavoidable,
    • manufacturing-related impurities used.

Neben der erwähnten einstufigen Wärmbehandlung lassen sich durch zusätzliche Aushärtungsschritte die mechanisch-technologischen Eigenschaften weiter verbessern. In diesem Fall werden die warmgeformten und abgeschreckten Teile zunächst 4 bis 10 Stunden bei 700 °C bis 750 °C geglüht, danach im Ofen mit 5 bis 25 °C pro Stunde um 150 °C kontrolliert abgekühlt und anschließend an Luft abgelegt. Alternativ können die Bauteile auch 30 min zwischen 730 °C bis 750 °C gehalten, danach im Ofen mit 5 bis 25 °C pro Stunde auf 700 °C und anschließend mit 2 bis 15 °C pro Stunde auf 580 °C kontrolliert abgekühlt werden. Zuletzt werden die Bauteile an Luft abgelegt.In addition to the single-stage heat treatment mentioned, the mechanical-technological properties can be further improved by additional curing steps. In this case, the thermoformed and quenched parts are first annealed for 4 to 10 hours at 700 ° C to 750 ° C, then cooled in an oven at 5 to 25 ° C per hour by 150 ° C and then placed in air. Alternatively, the components can also be kept between 730 ° C to 750 ° C for 30 minutes, then cooled in an oven at 5 to 25 ° C per hour to 700 ° C and then at 2 to 15 ° C per hour to 580 ° C. Finally, the components are placed in air.

Nach einer weiteren Abwandlung des Herstellungsverfahrens ist vorgesehen, daß die warmgeformten Teile vor dem Abschrecken in Wasser einer Lösungsglühung bei 1150 bis 1190°C unterworfen werden. Schließlich kann man die warmgeformten, lösungsgeglühten und in Wasser abgeschreckten Teile auch 4 bis 10 Stunden bei 700 bis 750 °C halten, danach im Ofen mit 5 bis 25 °C pro Stunde um 150°C und schließlich weiter an Luft abkühlen.According to a further modification of the production process, the thermoformed parts are subjected to solution annealing at 1150 to 1190 ° C. before quenching in water. Finally, the thermoformed, solution-annealed and water-quenched parts can also be kept at 700 to 750 ° C for 4 to 10 hours, then in the furnace at 5 to 25 ° C per hour by 150 ° C and finally further cooled in air.

Weitere Einzelheiten und Vorteile des Erfindungsgedankens werden anhand der nachfolgenden Versuchsergebnisse näher erläutert.Further details and advantages of the inventive concept are explained in more detail on the basis of the following test results.

In Tabelle 1 ist die chemische Zusammensetzung von 7 Legierungen angegeben, die - nach unterschiedlicher Wärmebehandlung - auf ihre mechanischen Eigenschaften bei Raumtemperatur (RT) und bei 260 °C untersucht worden sind. Die Ergebnisse sind in den Tabellen 2 bis 7 zusammengestellt.Table 1 shows the chemical composition of 7 alloys, which - after different heat treatment - have been examined for their mechanical properties at room temperature (RT) and at 260 ° C. The results are summarized in Tables 2 to 7.

Aus etwa 45 Kg schweren Gußblöcken wurden nach dem Lösungsglühen bei 1220°C Stangen mit einem Durchmesser von etwa 18 mm warmgeschmiedet und zwar bei Temperaturen oberhalb 1000°C. Danach wurden die Stangen entweder direkt in Wasser abgeschreckt oder nochmals lösungsgeglüht und dann in Wasser abgeschreckt. Anschließend wurden die so vorbereiteten Proben einer ein- bis dreistufigen Aushärtungsbehandlung unterworfen. In der ersten Stufe wurden Glühtemperaturen von 730 oder 750 °C und Glühzeiten von 8, 4 oder 0,5 Stunden angewandt. Beim zweistufigen Verfahren schloß sich hieran eine gesteuerte Abkühlung mit 15°C/h auf 600 oder 580 °C an, während beim dreistufigen Verfahren zunächst eine gesteuerte Abkühlung mit 5°C/h auf 700 °C und dann eine weitere gesteuerte Abkühlung mit 15°C/h auf 580 °C vorgenommen wurde, bevor die Proben der unbeeinflußten weiteren Abkühlung an Luft ausgesetzt wurden.After solution annealing at 1220 ° C., rods with a diameter of approximately 18 mm were hot forged from cast blocks weighing approximately 45 kg and at temperatures above 1000 ° C. The bars were then either directly quenched in water or solution annealed again and then quenched in water. The samples prepared in this way were then subjected to a one to three-stage curing treatment. In the first stage, annealing temperatures of 730 or 750 ° C and annealing times of 8, 4 or 0.5 hours were used. In the two-stage process, this was followed by controlled cooling at 15 ° C / h to 600 or 580 ° C, while in the three-stage process, first a controlled cooling at 5 ° C / h to 700 ° C and then a further controlled cooling at 15 ° C / h was carried out to 580 ° C before the samples were exposed to the unaffected further cooling in air.

Die Ergebnisse zeigen, daß die geforderten Mindestwerte der mechanischen Eigenschaften in allen Fällen erreicht und zum Teil erheblich übertroffen wurden. Ferner ist aus den Ergebnissen insgesamt zu ersehen, daß mit den verschiedenen Varianten der Wärmebehandlung unterschiedliche Werte der mechanischen Eigenschaften erreicht werden können, was für die Einstellung auf spezielle Anforderungsprofile vorteilhaft sein kann. Zugunsten höherer Bruchdehnungswerte kann man beispielsweise auf maximale Festigkeitswerte verzichten und umgekehrt. Abgesehen von dieser allgemeinen Tendenz, erkennt man aber auch, daß die höchsten Festigkeitswerte erreicht werden, wenn die warmgeformten Teile nicht noch einmal lösungsgeglüht, sondern direkt in Wasser abgeschreckt werden und daß die maximal erreichbare Festigkeit vom Summengehalt Aluminium plus Titan abhängig ist.The results show that the required minimum mechanical properties were achieved in all cases and in some cases considerably exceeded. Furthermore, it can be seen from the results as a whole that different values of the mechanical properties can be achieved with the different variants of the heat treatment, which can be advantageous for the adjustment to special requirement profiles. In favor of higher elongation at break values, for example, maximum strength values can be dispensed with and vice versa. Apart from this general tendency, it can also be seen that the highest strength values are achieved if the thermoformed parts are not solution annealed again, but are directly quenched in water and that the maximum achievable strength depends on the total aluminum plus titanium content.

Die Aluminium- und Titangehalte können aber nicht beliebig erhöht werden, weil dann nachteilige Ausscheidungsphasen auftreten, die selbst bei aufwendiger Wärmebehandlung nicht zu vermeiden bzw. zu kompensieren sind. Andererseits ist das im Rahmen der erfindungsgemäßen Zusammensetzung wegen der zahlreichen Alternativen bei der Wärmebehandlung immer möglich, jeweils optimale Festigkeitswerte zu erreichen, ohne nachteilige Gefügestrukturen in Kauf nehmen zu müssen. So wird die aufwendigere dreistufige Aushärtungsbehandlung beispielsweise dann angezeigt sein, wenn es darum geht, ein Absinken der Kerbschlagzähigkeit bei der Einstellung möglichst hoher Festigkeitswerte zu vermeiden.However, the aluminum and titanium contents cannot be increased arbitrarily, because disadvantageous precipitation phases then occur which cannot be avoided or compensated for even with complex heat treatment. On the other hand, in the context of the composition according to the invention, because of the numerous alternatives in the heat treatment, it is always possible to achieve optimum strength values in each case without having to put up with disadvantageous microstructures. For example, the more complex three-stage curing treatment will be indicated when it comes to avoiding a decrease in the impact strength when setting the highest possible strength values.

Zur Überprüfung der Spannungsrißkorrosionsbeständigkeit wurden Dreipunkt-Biegeproben im Autoklaven zwei verschiedenen Korrosionsmedien ausgesetzt. Je nach vorausgegangener Wärmebehandlung wurden die Proben mit unterschiedlichen Prüfspannungen belastet, wobei als Bezugsgröße die Werte 100 % Rpo,2 sowie 120 % Rpo,2 gewählt worden sind. Die Prüftemperaturen betrugen 232 ° C und 260 ° C.To check the resistance to stress corrosion cracking, three-point bending samples were exposed to two different corrosion media in an autoclave. Depending on the previous heat treatment, the samples were loaded with different test voltages, whereby the values 100% Rp o , 2 and 120% Rp o , 2 were chosen as reference values. The test temperatures were 232 ° C and 260 ° C.

Die Lösungen A und B, mit denen die Sauergas-Bedingungen simuliert werden, enthielten:

  • Lösung A: 25 % NaCI, 10 bar H2S und 50 bar C02
  • Lösung B: 25 % NaCI, 0,5 % Essigsäure, 1 g/I Schwefel und 12 bar H2S.
Solutions A and B, which are used to simulate sour gas conditions, contained:
  • Solution A: 25% NaCI, 10 bar H 2 S and 50 bar C0 2
  • Solution B: 25% NaCI, 0.5% acetic acid, 1 g / I sulfur and 12 bar H 2 S.

Die Ergebnisse dieser Korrosionsuntersuchungen mit Angabe der Prüfbedingungen sind in den Tabellen 8 bis 13 zusammengefaßt.The results of these corrosion tests and the test conditions are summarized in Tables 8 to 13.

Man erkennt, daß nach einem Prüfzyklus, der zwischen 23 bis 26 Tagen lag, keine der Proben einen Bruch zeigt oder einen Angriff, der auf Spannungsrißkorrosion hinweist.It can be seen that after a test cycle that was between 23 and 26 days, none of the samples showed a break or an attack that indicated stress corrosion cracking.

Die erfindungsgemäße Legierung zeigt demnach in neuartiger Weise eine mit aushärtbaren Werkstoffen bisher nicht erreichte Kombination hoher Festigkeit bei zugleich ausgezeichneter Beständigkeit in sehr aggressiven Sauergas-Medien.

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 The alloy according to the invention accordingly shows in a novel way a combination of high strength not yet achieved with curable materials and at the same time excellent resistance in very aggressive sour gas media.
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Claims (10)

1. Use of a hardenable nickel alloy having (in % by weight)
43 to 51 % nickel
19 to 24 % chromium
5 to 7.5 % molybdenum
0.4 to 2.5 % copper
up to 1 % manganese
up to 0.5 % silicon
up to 0.02% carbon
up to 2 % cobalt
0.3 to 1.8 % aluminium
0.9 to 2.2 % titanium

residue iron, including unavoidable impurities due to manufacture
as a material for the production of structural components for use in sour gas conditions and having a 0.2% proof stress of at least 500 N/mm2.
2. Use of the nickel alloy according to claim 1 as a material for the production of structural components which must have a 0.2% proof stress of at least 500 N/mm2, an elongation without necking As of at least 20%, a reduction in area at fracture of at least 25% and at room temperature a notched bar impact work of at least 54 J (ISO V sample).
3. A nickel alloy according to claim 1, characterized by
46 to 51 % nickel
20 to 23.5 % chromium
5 to 7 % molybdenum
1.5 to 2.2 % copper
up to 0.8 % manganese
up to 0.1 % silicon
up to 0.015% carbon
up to 2 % cobalt
0.4 to 0.9 % aluminium
1.5 to 2.1 % titanium

residue iron, including unavoidable impurities due to manufacture.
4. Use of the nickel alloy according to claim 3 for structural components which must have a 0.2% proof stress of at least 750 N/mm2, an elongation without necking As of at least 20%, a reduction in area at fracture of at least 25% and at room temperature a notched bar impact work of at least 54 J (ISO V sample).
5. A process for the production of structural components which must have in sour gas conditions a very good corrosion resistivity and a 0.2% proof stress of at least 500 N/mm2, characterized in that ingots are prepared from
a) an alloy having
43 to 51 % nickel
19 to 24 % chromium
5 to 7.5 % molybdenum
0.4 to 2.5 % copper
up to 1 % manganese
up to 0.5 % silicon
up to 0.02% carbon
up to 2 % cobalt
0.3 to 1.8 % aluminium
0.9 to 2.2 % titanium
residue iron, including unavoidable impurities due to manufacture,
b) the ingots are homogenized at 1220°C and then hot shaped above 1000 °C, the resulting components being quenched in water, and
c) the hot shaped and quenched components are hardened for up to 16 hours at 650 to 750 °C and then subjected to air cooling.
6. A process according to claim 5, characterized in that the ingots are produced from an alloy having: 46 to 51 % nickel
20 to 23.5 % chromium
5 to 7 % molybdenum
1.5 to 2.2 % copper
up to 0.8 % manganese
up to 0.1 % silicon
up to 0.015% carbon
up to 2 % cobalt
0.4 to 0.9 % aluminium
1.5 to 2.1 % titanium
residue iron, including unavoidable impurities due to manufacture.
7. A process according to claims 5 or 6, but wherein the hot shaped and quenched components are maintained for 4 to 10 hours at 700 to 750 °C, then cooled in the furnace by 150 °C at 5 to 25 °C per hour and finally further cooled in air.
8. A process according to claims 5 or 6, but wherein the hot shaped and quenched components are maintained for 30 minutes at 730 to 750 °C, then cooled in the furnace to 700 °C at 5 to 25 °C per hour, further cooled to 580 °C at 2 to 15 °C per hour and finally further cooled in air.
9. A process according to claims 5 or 6, but wherein prior to quenching in water, the hot shaped components are subjected to a solution annealing at 1150 to 1190 °C.
10. A process according to claim 9, but wherein the hot shaped, solution annealed components quenched in water are maintained for 4 to 10 hours at 700 to 750 °C, then cooled in the furnace by 150 °C at 5 to 25 °C per hour and finally further cooled in air.
EP89903692A 1988-03-26 1989-03-23 Hardenable nickel alloy Expired - Lifetime EP0410979B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT89903692T ATE102262T1 (en) 1988-03-26 1989-03-23 HARDENABLE NICKEL ALLOY.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3810336 1988-03-26
DE3810336A DE3810336A1 (en) 1988-03-26 1988-03-26 CURABLE NICKEL ALLOY

Publications (2)

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EP0410979A1 EP0410979A1 (en) 1991-02-06
EP0410979B1 true EP0410979B1 (en) 1994-03-02

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WO (1) WO1989009292A1 (en)

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Publication number Priority date Publication date Assignee Title
DE19645186A1 (en) * 1996-11-02 1998-05-07 Asea Brown Boveri Heat treatment process for material bodies made of a highly heat-resistant iron-nickel superalloy as well as heat-treated material bodies
US7785532B2 (en) * 2006-08-09 2010-08-31 Haynes International, Inc. Hybrid corrosion-resistant nickel alloys
CN104451339B (en) * 2014-12-23 2017-12-12 重庆材料研究院有限公司 Low nickel ageing strengthening sections abros and preparation method
US10718042B2 (en) * 2017-06-28 2020-07-21 United Technologies Corporation Method for heat treating components

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE546036A (en) *
GB531466A (en) * 1939-04-06 1941-01-06 Harry Etchells Improvements in alloys
US2777766A (en) * 1952-06-04 1957-01-15 Union Carbide & Carbon Corp Corrosion resistant alloys
US2977222A (en) * 1955-08-22 1961-03-28 Int Nickel Co Heat-resisting nickel base alloys
US4358511A (en) * 1980-10-31 1982-11-09 Huntington Alloys, Inc. Tube material for sour wells of intermediate depths
JPS57207143A (en) * 1981-06-12 1982-12-18 Sumitomo Metal Ind Ltd Alloy for oil well pipe with superior stress corrosion cracking resistance and hot workability
US4421571A (en) * 1981-07-03 1983-12-20 Sumitomo Metal Industries, Ltd. Process for making high strength deep well casing and tubing having improved resistance to stress-corrosion cracking
NO831752L (en) * 1982-05-17 1983-11-18 Kobe Steel Ltd AUSTENITIC Alloys with high nickel content.
US4652315A (en) * 1983-06-20 1987-03-24 Sumitomo Metal Industries, Ltd. Precipitation-hardening nickel-base alloy and method of producing same
US4685977A (en) * 1984-12-03 1987-08-11 General Electric Company Fatigue-resistant nickel-base superalloys and method
JPS61201759A (en) * 1985-03-04 1986-09-06 Sumitomo Metal Ind Ltd High strength and toughness welded steel pipe for line pipe
JPS6223950A (en) * 1985-07-23 1987-01-31 Kubota Ltd Alloy for electrically conductive roll for electroplating
US4750950A (en) * 1986-11-19 1988-06-14 Inco Alloys International, Inc. Heat treated alloy

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DE3810336A1 (en) 1989-10-05
US5429690A (en) 1995-07-04
EP0410979A1 (en) 1991-02-06
WO1989009292A1 (en) 1989-10-05
CA1334344C (en) 1995-02-14

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