EP0531776B1 - Heat-resistant, hot workable austenitic steel - Google Patents

Heat-resistant, hot workable austenitic steel Download PDF

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EP0531776B1
EP0531776B1 EP92114280A EP92114280A EP0531776B1 EP 0531776 B1 EP0531776 B1 EP 0531776B1 EP 92114280 A EP92114280 A EP 92114280A EP 92114280 A EP92114280 A EP 92114280A EP 0531776 B1 EP0531776 B1 EP 0531776B1
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austenitic steel
steel according
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weight
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EP0531776A1 (en
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Ulrich Dr.-Ing. Brill
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Krupp VDM GmbH
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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

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  • the invention relates to a heat-resistant, thermoformable austenitic steel and its use as a material for heat and corrosion-resistant objects.
  • this steel is an inexpensive alternative to the high nickel-containing materials, e.g. the nickel alloy according to material no. 2,4856.
  • this austenitic steel 1.4876 shows strong carburizing phenomena under strong carburizing conditions at temperatures above 900 ° C, which is expressed in a significant weight gain through strong carbide deposits and carbon absorption. As a result, the mechanical properties, in particular the long-term strength, are additionally adversely affected. Even under oxidizing / sulfidizing conditions such as in a gas atmosphere made of nitrogen and 10% SO2 at 750 ° C, austenitic steel 1.4876 shows significant damage due to sulfur absorption.
  • an austenitic steel consisting of (details in% by weight): max. 0.10% carbon, 1 - 5% silicon, max. 3% manganese, 15 - 30% chromium, 7 - 35% nickel, max. 0.10% aluminum, calcium + rare earths in total max. 0.10% and max. 0.03% nitrogen.
  • This steel shows the material no. 1.4876 an improved resistance to oxidation under cyclic loads at temperatures up to 1100 ° C., in particular due to carbon contents which are said to be below 0.10% by weight, and by limiting the sulfur content to values less than 0.003, preferably 0.0015% by weight .
  • carbon and nitrogen contents to less than 0.10 or 0.03% by weight in favor of improved resistance to oxidation, the heat resistance of the material in the temperature interval specified for its use is insufficient.
  • the limits on carbon, nitrogen and sulfur can only be achieved with great technical effort when melting this steel.
  • an austenitic steel consisting of (data in% by weight) carbon 0.10 to 0.20 silicon 2.5 to 3.0 manganese 0.2 to 0.5 phosphorus Max. 0.015 sulfur Max. 0.005 chrome 25 to 30 nickel 30 to 35 aluminum 0.05 to 0.15 Calcium 0.001 to 0.005 Rare earth 0.05 to 0.15 nitrogen 0.05 to 0.20
  • the steel according to the invention is advantageously suitable as a material for the production of objects which have to be resistant to carburization, sulfidation and oxidation at temperatures in the range from 500 to 1000 ° C., in particular in the case of cyclic loading. It is preferably used as a material for the production of plants for thermal waste disposal or for coal gasification and parts thereof. Especially when it comes to waste disposal in incineration plants, the furnace parts are subjected to high cyclical stresses due to changing temperatures during heating and cooling as well as fluctuations in the exhaust gas composition.
  • the steel according to the invention can be used without restriction as a material for the production of thermally stressed furnace components, such as support frames for furnaces, conveyor rails and conveyor belts.
  • the carbon and nitrogen contents in solution act as very efficient solid-solution strengthening elements and thus increase the heat resistance.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
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  • Organic Chemistry (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Heat Treatment Of Steel (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)
  • Load-Engaging Elements For Cranes (AREA)
  • Treatment Of Steel In Its Molten State (AREA)

Abstract

The invention relates to a heat resistant hot formable austenitic steel consisting of (in % by weight) -carbon0.10 to0.20-silicon2.5 to3.0-manganese0.2 to0.5-phosphorusmax0.015-sulphurmax0.005-chromium25 to30-nickel30 to35-aluminium0.05 to0.15-calcium0.001 to0.005-rare earths0.05 to0.15-nitrogen0.05 to0.20- residue iron and the usual impurities due to melting.

Description

Die Erfindung betrifft einen hitzebeständigen warmverformbaren austenitischen Stahl und seine Verwendung als Werkstoff für hitze- und korrosionsbeständige Gegenstände.The invention relates to a heat-resistant, thermoformable austenitic steel and its use as a material for heat and corrosion-resistant objects.

Für Gegenstände, die im Temperaturbereich von 500 bis 1000 °C beständig sein müssen gegen Aufkohlung, Sulfidierung und Oxidation, insbesondere bei zyklischer Beanspruchung, wird vorwiegend der austenitische Stahl mit der Werkstoff-Nr. 1.4876 gemäß Stahleisen-Liste des Vereins deutscher Eisenhüttenleute eingesetzt. Er besteht aus (in Gew.-%) max. 0,12 % Kohlenstoff, max. 1,0 % Silizium, max. 2,0 % Mangan, 19 - 23 % Chrom, 30 - 34 % Nickel, 0,15 - 0,60 % Titan, 0,15 - 0,60 % Aluminium, Rest Eisen.
Für weniger scharfe Korrosionsbedingungen ist dieser Stahl eine preisgünstige Alternative zu den hoch nickelhaltigen Werkstoffen, z.B. der Nickel-Legierung gemäß Werkstoff-Nr. 2.4856.
Dieser austenitische Stahl 1.4876 zeigt jedoch unter stark aufkohlenden Bedingungen bei Temperaturen oberhalb 900 °C starke Aufkohlungserscheinungen, die sich in einer deutlichen Gewichtszunahme durch starke Karbidausscheidungen und Kohlenstoffaufnahme ausdrücken. Hierdurch werden zusätzlich die mechanischen Eigenschaften, insbesondere die Langzeitfestigkeit ungünstig beeinflußt. Auch unter oxidierend/sulfidierenden Bedingungen wie z.B. in einer Gasatmosphäre aus Stickstoff und 10 % SO₂ bei 750 °C zeigt der austenitische Stahl 1.4876 deutliche Schädigungen durch Schwefelaufnahme.For objects that have to be resistant to carburization, sulfidation and oxidation in the temperature range from 500 to 1000 ° C, especially with cyclical stress, the austenitic steel with material no. 1.4876 used according to the steel iron list of the Association of German Ironworkers. It consists of (in% by weight) max. 0.12% carbon, max. 1.0% silicon, max. 2.0% manganese, 19-23% chromium, 30-34% nickel, 0.15-0.60% titanium, 0.15-0.60% aluminum, the rest iron.
For less severe corrosion conditions, this steel is an inexpensive alternative to the high nickel-containing materials, e.g. the nickel alloy according to material no. 2,4856.
However, this austenitic steel 1.4876 shows strong carburizing phenomena under strong carburizing conditions at temperatures above 900 ° C, which is expressed in a significant weight gain through strong carbide deposits and carbon absorption. As a result, the mechanical properties, in particular the long-term strength, are additionally adversely affected. Even under oxidizing / sulfidizing conditions such as in a gas atmosphere made of nitrogen and 10% SO₂ at 750 ° C, austenitic steel 1.4876 shows significant damage due to sulfur absorption.

Der aus der EP-PS 0 135 321 bekannte austenitische Stahl (Angaben in Gew.-%) mit max. 0,03 % Kohlenstoff, 20 - 35 % Chrom, 17 - 50 % Ni sowie 2 - 6 % Silizium, ist zwar aufgrund seines hohen Si-Gehaltes beständig gegen Korrosion in stark oxidierenden Mineralsäuren, wie Salpetersäure, eignet sich aber nicht für den Einsatz bei Temperaturen oberhalb von 500 °C unter aufkohlenden, sulfidierenden und oxidierenden Bedingungen.The austenitic steel known from EP-PS 0 135 321 (data in% by weight) with max. 0.03% carbon, 20 - 35% chromium, 17 - 50% Ni and 2 - 6% silicon, is resistant to corrosion in strongly oxidizing mineral acids such as nitric acid due to its high Si content, but is not suitable for use at temperatures above 500 ° C under carburizing, sulfidizing and oxidizing conditions.

In der GB-PS 2 036 077 ist ein austenitischer Stahl beschrieben, bestehend aus (Angaben in Gew.-%): max. 0,10 % Kohlenstoff, 1 - 5 % Silizium, max. 3 % Mangan, 15 - 30 % Chrom, 7 - 35 % Nickel, max. 0,10 % Aluminium, Calcium + Seltene Erden in Summe max. 0,10 %, sowie max. 0,03 % Stickstoff.In GB-PS 2 036 077 an austenitic steel is described, consisting of (details in% by weight): max. 0.10% carbon, 1 - 5% silicon, max. 3% manganese, 15 - 30% chromium, 7 - 35% nickel, max. 0.10% aluminum, calcium + rare earths in total max. 0.10% and max. 0.03% nitrogen.

Dieser Stahl zeigt gegenüber dem eingangs genannten Stahl der Werkstoff-Nr. 1.4876 eine verbesserte Oxidationsbeständigkeit unter zyklischer Belastung bei Temperaturen bis 1100 °C, insbesondere bedingt durch Kohlenstoffgehalte, die unter 0,10 Gew.-% liegen sollen, sowie durch eine Begrenzung des Schwefelgehaltes auf Werte kleiner 0,003, vorzugsweise 0,0015 Gew.-%. Durch die Begrenzung der Kohlenstoff- und Stickstoffgehalte auf kleiner 0,10 bzw. 0,03 Gew.-% zugunsten einer verbesserten Oxidationsbeständigkeit ist jedoch die Warmfestigkeit des Werkstoffes in dem für seine Verwendung angegebenen Temperaturintervall unzureichend. Darüber hinaus sind die Begrenzungen an Kohlenstoff, Stickstoff und Schwefel bei der Erschmelzung dieses Stahls nur mit hohem technischen Aufwand erzielbar.This steel shows the material no. 1.4876 an improved resistance to oxidation under cyclic loads at temperatures up to 1100 ° C., in particular due to carbon contents which are said to be below 0.10% by weight, and by limiting the sulfur content to values less than 0.003, preferably 0.0015% by weight . However, by limiting the carbon and nitrogen contents to less than 0.10 or 0.03% by weight in favor of improved resistance to oxidation, the heat resistance of the material in the temperature interval specified for its use is insufficient. In addition, the limits on carbon, nitrogen and sulfur can only be achieved with great technical effort when melting this steel.

Es ist Aufgabe der Erfindung, einen austenitischen Stahl zu schaffen, der unter aufkohlenden, sulfidierenden und oxidierenden Bedingungen, insbesondere unter zyklischer Beanspruchung, im Temperaturbereich von 500 bis 1000 °C mit ausreichender Warmfestigkeit ohne Einschränkung einsetzbar ist.It is an object of the invention to provide an austenitic steel which can be used without restriction under carburizing, sulfidizing and oxidizing conditions, in particular under cyclic loading, in the temperature range from 500 to 1000 ° C. with sufficient heat resistance.

Gelöst wird diese Aufgabe durch einen austenitischen Stahl, bestehend aus (Angaben in Gew.-%) Kohlenstoff 0,10 bis 0,20 Silizium 2,5 bis 3,0 Mangan 0,2 bis 0,5 Phosphor max. 0,015 Schwefel max. 0,005 Chrom 25 bis 30 Nickel 30 bis 35 Aluminium 0,05 bis 0,15 Calcium 0,001 bis 0,005 Seltene Erden 0,05 bis 0,15 Stickstoff 0,05 bis 0,20 This task is solved by an austenitic steel consisting of (data in% by weight) carbon 0.10 to 0.20 silicon 2.5 to 3.0 manganese 0.2 to 0.5 phosphorus Max. 0.015 sulfur Max. 0.005 chrome 25 to 30 nickel 30 to 35 aluminum 0.05 to 0.15 Calcium 0.001 to 0.005 Rare earth 0.05 to 0.15 nitrogen 0.05 to 0.20

Rest Eisen und übliche erschmelzungsbedingte Verunreinigungen.Remainder iron and usual contamination due to melting.

Der erfindungsgemäße Stahl eignet sich vorteilhaft als Werkstoff zur Herstellung von Gegenständen, die bei Temperaturen im Bereich von 500 bis 1000 °C, insbesondere bei zyklischer Beanspruchung, beständig sein müssen gegen Aufkohlung, Sulfidierung und Oxidation. Er wird bevorzugt eingesetzt als Werkstoff zur Herstellung von Anlagen zur thermischen Müllentsorgung oder zur Kohlevergasung und Teilen davon. Insbesondere bei der Müllentsorgung in Verbrennungsanlagen werden die Ofenteile stark durch wechselnde Temperaturen beim Auf- und Abheizen sowie durch Schwankungen in der Abgaszusammensetzung zyklisch beansprucht.The steel according to the invention is advantageously suitable as a material for the production of objects which have to be resistant to carburization, sulfidation and oxidation at temperatures in the range from 500 to 1000 ° C., in particular in the case of cyclic loading. It is preferably used as a material for the production of plants for thermal waste disposal or for coal gasification and parts thereof. Especially when it comes to waste disposal in incineration plants, the furnace parts are subjected to high cyclical stresses due to changing temperatures during heating and cooling as well as fluctuations in the exhaust gas composition.

Er ist auch hervorragend geeignet als Werkstoff für Heizleiter, bei denen es in erster Linie neben einer guten Oxidationsbeständigkeit bei Temperaturen bis 1000 °C auch auf eine gute Warmfestigkeit ankommt.
Da in Öfen, wie Brennöfen, die Heizgase stark aufkohlend auf Ofeneinbauteile wirken, und außerdem je nach verwendetem Brennstoff Kontaminationen durch Schwefel auftreten können, kann der erfindungsgemäße Stahl ohne Einschränkung als Werkstoff zur Herstellung von thermisch beanspruchten Ofeneinbauteilen, wie Stützgerüste für Brennöfen, Transportschienen und Transportbänder eingesetzt werden.It is also excellently suited as a material for heating conductors, where, in addition to good oxidation resistance at temperatures up to 1000 ° C, good heat resistance is also important.
Because in stoves, such as kilns, the heating gases have a strong carburizing effect on built-in furnace parts, and also contaminations depending on the fuel used can occur due to sulfur, the steel according to the invention can be used without restriction as a material for the production of thermally stressed furnace components, such as support frames for furnaces, conveyor rails and conveyor belts.

Das vorteilhafte Korrosionsverhalten des erfindungsgemäßen Stahls wird erreicht durch:

  • Siliziumgehalte von 2,5 - 3,0 Gew.-% in Verbindung mit 25 - 30 Gew.-% Chrom wirken sich günstig auf die Sulfidierungsbeständigkeit aus. Außerdem ist bei diesen Siliziumgehalten eine noch ausreichende Warmverformbarkeit durch Walzen und Schmieden gegeben. Die gewählten Siliziumgehalte beeinträchtigen ebenfalls nicht die Schweißbarkeit des Werkstoffes.
  • Der Nickelgehalt von 30 - 35 Gew.-%, in Verbindung mit 2,5 - 3,0 Gew.-% Silizium bedingt die Beständigkeit in stark aufkohlenden Medien.
  • Die Chromgehalte von 25 - 30 Gew.-% in Verbindung mit einem Calciumgehalt von 0,001 - 0,005 Gew.-%, sowie einem Gehalt an Seltenen Erden (wie Cer, Lanthan und den anderen Elementen der Gruppe der Aktiniden und Lanthanoiden) in Höhe von insgesamt 0,05 - 0,15 Gew.-% bewirken eine ausgezeichnete Oxidationsbeständigkeit, insbesondere unter zyklisch/thermischen Betriebsbedingungen, durch den Aufbau einer dünnen, gut haftenden und schützenden Oxidschicht.
The advantageous corrosion behavior of the steel according to the invention is achieved by:
  • Silicon contents of 2.5 - 3.0% by weight in combination with 25 - 30% by weight of chromium have a favorable effect on the sulfidation resistance. In addition, with these silicon contents there is still sufficient hot formability by rolling and forging. The selected silicon contents also do not affect the weldability of the material.
  • The nickel content of 30 - 35% by weight, in combination with 2.5 - 3.0% by weight of silicon, determines the resistance in strongly carburizing media.
  • The chromium contents of 25 - 30 wt .-% in connection with a calcium content of 0.001 - 0.005 wt .-%, as well as a content of rare earths (such as cerium, lanthanum and the other elements of the group of actinides and lanthanoids) in the total amount 0.05 - 0.15% by weight result in excellent oxidation resistance, especially under cyclic / thermal operating conditions, due to the build-up of a thin, well-adhering and protective oxide layer.

In Ergänzung der für das Korrosionsverhalten wichtigen Gehaltsbereiche der vorstehend genannten Elemente ist

  • die Festlegung des Kohlenstoffgehaltes auf 0,10 - 0,20 Gew.-% in Verbindung mit Stickstoffgehalten von 0,05 - 0,20 Gew.-% ursächlich für die gute Warm- und Zeitstandfestigkeit des erfindungsgemäßen Stahls.
In addition to the content ranges of the above-mentioned elements that are important for the corrosion behavior
  • the determination of the carbon content at 0.10-0.20% by weight in connection with nitrogen contents of 0.05-0.20% by weight is the reason for the good heat and creep rupture strength of the steel according to the invention.

Die in Lösung befindlichen Gehalte an Kohlenstoff und Stickstoff sind als sehr effiziente mischkristallverfestigende und somit die Warmfestigkeit steigernde Elemente wirksam.The carbon and nitrogen contents in solution act as very efficient solid-solution strengthening elements and thus increase the heat resistance.

Darüber hinaus bewirken die Kohlenstoff- und Stickstoffgehalte in den angegebenen Gehaltsgrenzen gerade in dem für den Einsatz vorgegegebenen Temperaturintervall eine verstärkte Ausscheidung von Chromkarbiden und -karbonitriden, die ebenfalls eine Steigerung der Warmfestigkeit bewirken.In addition, the carbon and nitrogen contents within the specified content limits result in an increased excretion of chromium carbides and carbonitrides, which also likewise result in an increase in the heat resistance, especially in the temperature range specified for the use.

Im folgenden wird der erfindungsgemäße Stahl (Leg. A) im Vergleich zum bekannten Stahl 1.4876 (Leg. B) näher erläutert.The steel according to the invention (Leg. A) is explained in more detail below in comparison with the known steel 1.4876 (Leg. B).

Die Ist-Analysen der Vergleichslegierungen A und B sind in Tabelle 1 aufgeführt (Angaben in Gew.-%) Tabelle 1 Leg. A Leg. B Kohlenstoff 0,14 0,06 Silizium 2,77 0,45 Mangan 0,36 0,70 Phosphor 0,014 0,010 Schwefel 0,003 0,003 Chrom 27,75 20,50 Nickel 30,40 30,50 Aluminium 0,05 0,25 Calcium 0,002 --- Seltene Erden 0,075 --- Stickstoff 0,08 0,02 Titan --- 0,34 Eisen Rest Rest

  • Figur 1 zeigt das Aufkohlungsverhalten der Leg. A im Vergleich zu Leg. B.
    Dargestellt ist hier die spezifische Massenänderung in g/m² über der Zeit in Stunden. Das Prüfmedium war ein Gasgemisch aus CH₄/H₂ mit einer Kohlenstoffaktivität von ac = 0,8. Die Prüftemperatur betrug 1000 °C. Die Prüfung erfolgte zyklisch, d. h. bei einer Zyklus-Dauer von 24 Stunden betrug die Haltezeit auf Prüftemperatur 16 Stunden bei insgesamt 8 Stunden Auf- und Abheizen.
    Die erfindungsgemäße Leg. A zeichnet sich durch eine deutlich geringere Massenzunahme aus gegenüber der Vergleichslegierung B.
  • Figur 2
    Diese Darstellung entspricht in Ausführung und Versuchsdurchführung der Darstellung in Fig. 1. Lediglich das Versuchsmedium war in diesem Fall Stickstoff + 10 % SO₂ bei 750 °C zur Prüfung der Sulfidierungsbeständigkeit. In diesem Test ergibt sich eine Überlegenheit von Leg. A gegenüber Leg. B mit Bezug auf die Massenänderung, insbesondere nach Prüfzeiten über 800 Stunden.
  • Figur 3 beschreibt das zyklische Oxidationsverhalten der Vergleichswerkstoffe A und B in Luft bei 1000 °C. Die Versuchsbedingungen und die Darstellung der Ergebnisse entsprechen Fig. 1.
    Das deutlich verbesserte Oxidationsverhalten der erfindungsgemäßen Leg. A unter zyklischer Temperaturbeaufschlagung ist ersichtlich aus der selbst nach mehr als 1000 Stunden Prüfzeit noch gemessenen Gewichtszunahme (Massenänderung = (+)), was ein Beweis für das Vorhandensein einer gut haftenden Oxidschicht ist.
    Die Massenverluste der Vergleichslegierung B (Massenänderung = (-)) bedeuten, daß diese Legierung unter den vorliegenden oxidierenden Bedingungen starke Zunderabplatzungen aufweist, somit beim praktischen Einsatz versagt.
  • Figur 4 zeigt die Warmfestigkeit in MPa am Beispiel der 0,2 %-Dehngrenze (Rp0,2) in Abhängigkeit von der Prüftemperatur in °C.
    Die erfindungsgemäße Legierung A weist nicht nur im Temperaturbereich von 500 bis 1000 °C eine um ca. 100 MPa höhere Dehngrenze auf, sondern auch im Bereich von Raumtemperatur bis 500 °C. Dies wirkt sich besonders vorteilhaft bei Auf- und Abheizvorgängen aus, denen der Werkstoff beim praktischen Einsatz zwangsläufig unterliegt.
The actual analyzes of the comparative alloys A and B are listed in Table 1 (data in% by weight) Table 1 Leg. A Leg. B carbon 0.14 0.06 silicon 2.77 0.45 manganese 0.36 0.70 phosphorus 0.014 0.010 sulfur 0.003 0.003 chrome 27.75 20.50 nickel 30.40 30.50 aluminum 0.05 0.25 Calcium 0.002 --- Rare earth 0.075 --- nitrogen 0.08 0.02 titanium --- 0.34 iron rest rest
  • Figure 1 shows the carburizing behavior of the leg. A compared to Leg. B.
    The specific mass change in g / m² over time in hours is shown here. The test medium was a gas mixture of CH₄ / H₂ with a carbon activity of a c = 0.8. The test temperature was 1000 ° C. The test was carried out cyclically, ie with a cycle time of 24 hours, the holding time at test temperature was 16 hours with a total of 8 hours heating up and cooling down.
    The Leg according to the invention. A is characterized by a significantly smaller increase in mass compared to the comparative alloy B.
  • Figure 2
    This representation corresponds in execution and test execution of the representation in Fig. 1. Only the test medium was nitrogen + 10% SO₂ at 750 ° C in this case to test the sulfidation resistance. Leg is superior in this test. A versus Leg. B with reference to the mass change, especially after test times over 800 hours.
  • Figure 3 describes the cyclic oxidation behavior of the comparison materials A and B in air at 1000 ° C. The test conditions and the presentation of the results correspond to FIG. 1.
    The significantly improved oxidation behavior of the leg according to the invention. A under cyclical temperature exposure can be seen from the weight gain (change in mass = (+)) measured even after a test time of more than 1000 hours, which is evidence of the presence of a well adhering oxide layer.
    The mass losses of the comparative alloy B (change in mass = (-)) mean that this alloy has severe scale flaking under the oxidizing conditions present, and therefore fails in practical use.
  • Figure 4 shows the heat resistance in MPa using the example of the 0.2% proof stress (Rp 0.2 ) as a function of the test temperature in ° C.
    Alloy A according to the invention not only has an elongation limit which is approximately 100 MPa higher in the temperature range from 500 to 1000 ° C., but also in the range from room temperature to 500 ° C. This has a particularly advantageous effect on heating and cooling processes, to which the material is inevitably subject in practical use.

Claims (6)

  1. A heat resistant hot workable austenitic steel, consisting of (in % by weight) carbon 0.10 to 0.20 silicon 2.5 to 3.0 manganese 0.2 to 0.5 phosphorus max. 0.015 sulphur max. 0.005 chromium 25 to 30 nickel 30 to 35 aluminium 0.05 to 0.15 calcium 0.001 to 0.005 rare earths 0.05 to 0.15 nitrogen 0.05 to 0.20
    residue iron and the usual impurities due to melting.
  2. Use of an austenitic steel according to claim 1 as a material for the production of articles which must be resistant to carbonization, sulphidization and oxidation at temperatures in the range of 500 to 1000°C, more particularly with cyclic stressing.
  3. Use of an austenitic steel according to claim 1 as a material for the production of installations for the thermal disposal of garbage and parts of such installations.
  4. Use of an austenitic steel according to claim 1 as a material for the production of installations for coal gasification and parts of such installations.
  5. Use of an austenitic steel according to claim 1 as a material for heating conductors.
  6. Use of an austenitic steel according to claim 1 as a material for the production of furnace furniture, such as supporting frames for firing kilns, conveyor rails and belts.
EP92114280A 1991-09-11 1992-08-21 Heat-resistant, hot workable austenitic steel Expired - Lifetime EP0531776B1 (en)

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DE4130140 1991-09-11
DE4130140A DE4130140C1 (en) 1991-09-11 1991-09-11

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EP0531776B1 true EP0531776B1 (en) 1995-11-15

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US (1) US5302097A (en)
EP (1) EP0531776B1 (en)
JP (1) JPH05195167A (en)
AT (1) ATE130376T1 (en)
DE (2) DE4130140C1 (en)

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DE4130139C1 (en) * 1991-09-11 1992-08-06 Krupp-Vdm Ag, 5980 Werdohl, De
DE19524234C1 (en) * 1995-07-04 1997-08-28 Krupp Vdm Gmbh Kneadable nickel alloy
US7118636B2 (en) * 2003-04-14 2006-10-10 General Electric Company Precipitation-strengthened nickel-iron-chromium alloy

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JPS5114118A (en) * 1974-07-25 1976-02-04 Nisshin Steel Co Ltd Oosutenaitokeitainetsuko
SE419102C (en) * 1974-08-26 1985-12-05 Avesta Ab APPLICATION OF A CHROME NICKEL NUMBER WITH AUSTENITIC STRUCTURE FOR CONSTRUCTIONS REQUIRING HIGH EXTREME CRIME RESISTANCE AT CONSTANT TEMPERATURE UP TO 1200? 59C
JPS5456018A (en) * 1977-10-12 1979-05-04 Sumitomo Metal Ind Ltd Austenitic steel with superior oxidation resistance for high temperature use
JPS6033345A (en) * 1983-08-05 1985-02-20 Sumitomo Metal Ind Ltd Nitric acid resistant austenite stainless steel
US4853185A (en) * 1988-02-10 1989-08-01 Haynes International, Imc. Nitrogen strengthened Fe-Ni-Cr alloy

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JPH05195167A (en) 1993-08-03
US5302097A (en) 1994-04-12
DE4130140C1 (en) 1992-11-19
DE59204329D1 (en) 1995-12-21
ATE130376T1 (en) 1995-12-15
EP0531776A1 (en) 1993-03-17

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