EP0442545A1 - Process for producing heat treated profiles and bodies - Google Patents
Process for producing heat treated profiles and bodies Download PDFInfo
- Publication number
- EP0442545A1 EP0442545A1 EP91200063A EP91200063A EP0442545A1 EP 0442545 A1 EP0442545 A1 EP 0442545A1 EP 91200063 A EP91200063 A EP 91200063A EP 91200063 A EP91200063 A EP 91200063A EP 0442545 A1 EP0442545 A1 EP 0442545A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- profiles
- temperature
- minutes
- moldings
- heat treatment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- 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
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/10—Alloys containing non-metals
Definitions
- the invention relates to a method for producing heat-treated profiles and moldings from oxide dispersion-hardened superalloys based on nickel with a rough structure formed from stem-shaped grains.
- the prefabricated parts consisting of profiles or moldings made of oxide dispersion-hardened superalloys based on nickel, are used due to their excellent mechanical-technological properties at comparatively high temperatures in thermal mechanical engineering, in particular as a material for the blades of the rotor of thermal turbomachines.
- alloy powders with a grain size of ⁇ 0.5 mm, preferably 10 to 500 ⁇ m are produced by mechanical alloying for the production of profiles and moldings from oxide dispersion-hardened nickel-based superalloys from powder mixtures containing the alloy components. generated, then compressed by extrusion or hot pressing, such as hot isostatic pressing, hot forging or the like, under vacuum or inert gas in appropriately designed molds and then subjected to a zone annealing process at temperatures of 1150 to 1350 ° C.
- the profiles or shaped bodies are guided in the forming direction at a speed of up to 240 mm / h through the induction coil of a heating device, the axial temperature / displacement gradient being 7 to 20 ° C / mm.
- This zone annealing creates a recrystallization front that is perpendicular to the axial temperature / path gradient, behind which there are longitudinal, coarse, stem-shaped grains in the longitudinal direction, in the longitudinal direction of which the profile or shaped body has the highest mechanical strength (EP-A-0 232 477).
- zone annealing process involves considerable effort for the heating device, since certain temperature ranges and temperature gradients have to be observed. Furthermore, the production of the profiles or shaped bodies with a coarse structure formed from stem-shaped grains takes place too slowly. In addition, zone annealing is only suitable for prismatic profiles.
- the solution to this problem is that the profiles or moldings of a 5 to 90 min preheat treatment at temperatures of 950 to 1180 ° C and then an isothermal heat treatment at temperatures of> 1180 to 1300 ° C for a period of 5 to 120 min be subjected.
- the recrystallization structure produced by this heat treatment according to the invention and consisting of stem-shaped grains is very similar to the stem-shaped recrystallization structure produced by zone annealing and has similar mechanical-technological properties.
- the preheating treatment lasts 10 to 60 minutes and is preferably carried out at temperatures from 1050 to 1170 ° C., in particular at temperatures from 1085 to 1140 ° C.
- the isothermal heat treatment lasts 30 to 60 minutes and is carried out at temperatures from 1190 to 1250 ° C.
- zone annealing can also be carried out.
- the zone annealing is carried out in such a way that the profile is moved through the heating zone at a speed of 200 to 2000 mm / h and is thereby heated to a temperature of 950 to 1150 ° C., the temperature / displacement gradient in the heating zone 1 is up to 20 ° C / mm.
- the longitudinal section shown in the drawing in a magnification of 5.3 times through the profile treated according to the invention shows that the fine-grained structure of the extruded molded body has been converted into a coarse structure with elongated grains.
- a 20 mm diameter rod made of the same nickel-based superalloy was moved through a heating zone at a constant feed rate of 950 mm / h, heated to a temperature of 1095 ° C and then subjected to an isothermal heat treatment at a temperature of 1200 ° C and 60 min duration.
- the fine-grained structure of the extruded round profile is converted into a uniform coarse structure with elongated grains.
- the elongated grains have an average length of 20 mm, a width of 0.5 mm and a thickness of 0.5 mm.
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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)
- Powder Metallurgy (AREA)
Abstract
Description
Die Erfindung betrifft ein Verfahren zur Herstellung wärmebehandelter Profile und Formkörper aus oxiddispersionsgehärteten Superlegierungen auf Nickelbasis mit einem aus stengelförmigen Körnern gebildeten Grobgefüge.The invention relates to a method for producing heat-treated profiles and moldings from oxide dispersion-hardened superalloys based on nickel with a rough structure formed from stem-shaped grains.
Die aus Profilen oder Formkörpern aus oxiddispersionsgehärteten Superlegierungen auf Nickelbasis bestehenden Fertigteile werden bedingt durch ihre ausgezeichneten mechanisch-technologischen Eigenschaften bei vergleichsweise hohen Temperaturen im thermischen Maschinenbau, insbesondere als Werkstoff für die Schaufeln des Rotors thermischer Strömungsmaschinen eingesetzt.The prefabricated parts, consisting of profiles or moldings made of oxide dispersion-hardened superalloys based on nickel, are used due to their excellent mechanical-technological properties at comparatively high temperatures in thermal mechanical engineering, in particular as a material for the blades of the rotor of thermal turbomachines.
Bekanntermaßen werden zur Herstellung von Profilen und Formkörpern aus oxiddispersionsgehärteten Superlegierungen auf Nickelbasis aus die Legierungskomponenten enthaltenden Pulvergemengen durch mechanisches Legieren Legierungspulver mit einer Korngröße von < 0,5 mm, vorzugsweise 10 bis 500 µm. erzeugt, dann durch Strangpressen oder Heißpressen, wie heißisostatisches Pressen, Heißschmieden oder dergleichen, unter Vakuum oder Schutzgas in entsprechend gestalteten Formwerkzeugen verdichtet und anschließend einem Zonenglühprozeß bei Temperaturen von 1150 bis 1350°C unterzogen. Dabei werden die Profile bzw. Formkörper in Umformrichtung mit einer Geschwindigkeit von bis zu 240 mm/h durch die Induktionsspule einer Heizeinrichtung geführt, wobei der axiale Temperatur/Weg-Gradient 7 bis 20°C/mm beträgt. Durch dieses Zonenglühen entsteht eine senkrecht zum axialen Temperatur/Weg-Gradienten stehende Rekristallisationsfront, hinter der in Umformrichtung liegende längsgerichtete grobe stengelförmige Körner vorliegen, in deren Längsrichtung das Profil bzw. der Formkörper höchste mechanische Beanspruchbarkeit besitzt (EP-A-0 232 477).As is known, alloy powders with a grain size of <0.5 mm, preferably 10 to 500 μm, are produced by mechanical alloying for the production of profiles and moldings from oxide dispersion-hardened nickel-based superalloys from powder mixtures containing the alloy components. generated, then compressed by extrusion or hot pressing, such as hot isostatic pressing, hot forging or the like, under vacuum or inert gas in appropriately designed molds and then subjected to a zone annealing process at temperatures of 1150 to 1350 ° C. The profiles or shaped bodies are guided in the forming direction at a speed of up to 240 mm / h through the induction coil of a heating device, the axial temperature / displacement gradient being 7 to 20 ° C / mm. This zone annealing creates a recrystallization front that is perpendicular to the axial temperature / path gradient, behind which there are longitudinal, coarse, stem-shaped grains in the longitudinal direction, in the longitudinal direction of which the profile or shaped body has the highest mechanical strength (EP-A-0 232 477).
Allerdings ist das Zonenglühverfahren mit einem beachtlichen Aufwand für die Heizvorrichtung verbunden, da bestimmte Temperaturbereiche und Temperaturgradienten eingehalten werden müssen. Ferner erfolgt die Herstellung der Profile bzw. Formkörper mit einem aus stengelförmigen Körnern gebildeten Grobgefüge zu langsam. Darüber hinaus ist das Zonenglühen nur für prismatische Profile geeignet.However, the zone annealing process involves considerable effort for the heating device, since certain temperature ranges and temperature gradients have to be observed. Furthermore, the production of the profiles or shaped bodies with a coarse structure formed from stem-shaped grains takes place too slowly. In addition, zone annealing is only suitable for prismatic profiles.
Es ist daher die Aufgabe der vorliegenden Erfindung, die im Rahmen des eingangs beschriebenen Verfahrens durchgeführte Wärmebehandlung der verfestigten Profile bzw. Formkörper so zu gestalten, daß aus dem Feinkorn-Ausgangsgefüge des verfestigten Profils bzw. Formkörpers in relativ kurzer Zeit ein Grobkorngefüge mit in Längsrichtung orientierten stengelförmigen Körnern und einem Längen/Dicken-Verhältnis von > 15 : 1 herstellbar ist.It is therefore the object of the present invention to design the heat treatment of the solidified profiles or shaped bodies carried out in the process described at the outset in such a way that a coarse grain structure with a longitudinal orientation is obtained from the fine-grain starting structure of the solidified profile or shaped body in a relatively short time stem-shaped grains and a length / thickness ratio of> 15: 1 can be produced.
Die Lösung dieser Aufgabe besteht darin, daß die Profile bzw. Formkörper einer 5 bis 90 min dauernden Vorwärmebehandlung bei Temperaturen von 950 bis 1180°C und anschließend einer isothermen Wärmebehandlung bei Temperaturen von > 1180 bis 1300°C für die Dauer von 5 bis 120 min unterworfen werden. Das durch diese erfindungsgemäße Wärmebehandlung erzeugte, aus stengelförmigen Körnern bestehende Rekristallisationsgefüge ist dem durch Zonenglühen erzeugten stengelförmigen Rekristallisationsgefüge sehr ähnlich und besitzt ähnliche mechanisch-technologische Eigenschaften.The solution to this problem is that the profiles or moldings of a 5 to 90 min preheat treatment at temperatures of 950 to 1180 ° C and then an isothermal heat treatment at temperatures of> 1180 to 1300 ° C for a period of 5 to 120 min be subjected. The recrystallization structure produced by this heat treatment according to the invention and consisting of stem-shaped grains is very similar to the stem-shaped recrystallization structure produced by zone annealing and has similar mechanical-technological properties.
Im Rahmen der vorzugsweisen Ausgestaltung der Erfindung dauert die Vorwärmebehandlung 10 bis 60 min und wird vorzugsweise bei Temperaturen von 1050 bis 1170°C, insbesondere bei Temperaturen von 1085 bis 1140°C durchgeführt.In the preferred embodiment of the invention, the preheating treatment lasts 10 to 60 minutes and is preferably carried out at temperatures from 1050 to 1170 ° C., in particular at temperatures from 1085 to 1140 ° C.
In den meisten Fällen reicht es aus, wenn die isotherme Wärmebehandlung 30 bis 60 min dauert und bei Temperaturen von 1190 bis 1250°C durchgeführt wird.In most cases it is sufficient if the isothermal heat treatment lasts 30 to 60 minutes and is carried out at temperatures from 1190 to 1250 ° C.
Anstelle der Vorwärmebehandlung des Profils kann auch eine Zonenglühung durchgeführt werden. Die Zonenglühung wird in der Weise durchgeführt, daß das Profil mit einer Geschwindigkeit von 200 bis 2000 mm/h durch die Aufheizzone bewegt und dabei auf eine Temperatur von 950 bis 1150°C aufgeheizt wird, wobei der Temperatur/Weg-Gradient in der Aufheizzone 1 bis 20°C/mm beträgt.Instead of preheating the profile, zone annealing can also be carried out. The zone annealing is carried out in such a way that the profile is moved through the heating zone at a speed of 200 to 2000 mm / h and is thereby heated to a temperature of 950 to 1150 ° C., the temperature / displacement gradient in the heating zone 1 is up to 20 ° C / mm.
Die Erfindung ist im folgenden durch zwei Ausführungsbeispiele näher erläutert.The invention is explained in more detail below by two exemplary embodiments.
In einer Hochenergie-Kugelmühle wurde aus getrennt zugegebenen Metallpulvern durch Intensivmahlen eine pulverförmige oxiddispersionsgehärtete Superlegierung der Zusammensetzung 17,0 % Chrom, 6,0 % Aluminium, 2,0 % Molybdän, 3,5 % Wolfram, 2,0 % Tantal, 0,15 % Zirkonium, 0,01 % Bor, < 0,05 % Kohlenstoff, 1,1 % Yttriumoxid, Rest Nickel erzeugt. Das Pulver wurde anschließend zu einem zylindrischen Profil mit einer Länge von 2000 mm und einem Durchmesser von 15 mm stranggepreßt. In diesem Zustand besteht der Werkstoff aus nahezu äquiaxialen Körnern mit einem mittleren Durchmesser von 0,4 µm. Anschließend wurde das Profil einer 15 min dauernden Vorwärmebehandlung bei einer Temperatur von 1135°C und danach einer isothermen Wärmebehandlung bei einer Temperatur von 1230°C und 60 min Dauer unterworfen. Der in der Zeichnung in 5,3-facher Vergrößerung wiedergegebene Längsschnitt durch das erfindungsgemäß behandelte Profil zeigt, daß das feinkörnige Gefüge des stranggepreßten Formkörpers in ein Grobgefüge mit langgestreckten Körnern überführt worden ist.In a high-energy ball mill, separately added metal powders were intensively ground to give a powdery oxide dispersion-hardened superalloy with the composition 17.0% chromium, 6.0% aluminum, 2.0% molybdenum, 3.5% tungsten, 2.0% tantalum, 15% zirconium, 0.01% boron, <0.05% carbon, 1.1% yttrium oxide, the rest nickel produced. The powder was then extruded into a cylindrical profile with a length of 2000 mm and a diameter of 15 mm. In this state, the material consists of almost equiaxial grains with an average diameter of 0.4 µm. The profile was then subjected to a preheating treatment at a temperature of 1135 ° C. for 15 minutes and then to an isothermal heat treatment at a temperature of 1230 ° C. and a duration of 60 minutes. The longitudinal section shown in the drawing in a magnification of 5.3 times through the profile treated according to the invention shows that the fine-grained structure of the extruded molded body has been converted into a coarse structure with elongated grains.
Eine aus der gleichen Superlegierung auf Nickelbasis auf pulvermetallurgischem Wege erzeugte Stange von 20 mm Durchmesser wurde mit einer konstanten Vorschubgeschwindigkeit von 950 mm/h durch eine Aufheizzone bewegt, dabei auf eine Temperatur von 1095°C aufgeheizt und danach einer isothermen Wärmebehandlung bei einer Temperatur von 1200°C und 60 min Dauer unterzogen. Das feinkörnige Gefüge des stranggepreßten Rundprofils wird in ein gleichmäßiges Grobgefüge mit langgestreckten Körnern überführt. Die langgestreckten Körner besitzen eine durchschnittliche Länge von 20 mm, eine Breite von 0,5 mm und eine Dicke von 0,5 mm.A 20 mm diameter rod made of the same nickel-based superalloy was moved through a heating zone at a constant feed rate of 950 mm / h, heated to a temperature of 1095 ° C and then subjected to an isothermal heat treatment at a temperature of 1200 ° C and 60 min duration. The fine-grained structure of the extruded round profile is converted into a uniform coarse structure with elongated grains. The elongated grains have an average length of 20 mm, a width of 0.5 mm and a thickness of 0.5 mm.
Die mit dem erfindungsgemäßen Verfahren erzielten Vorteile bestehen darin, daß mit herkömmlichen Mitteln in relativ kurzer Zeit Profile bzw. Formkörper aus oxiddispersionsgehärteten Superlegierungen auf Nickelbasis mit in Umformrichtung langgestreckten groben Körnern herstellbar sind.The advantages achieved with the method according to the invention are that profiles or moldings can be produced in a relatively short time from oxide dispersion-hardened nickel-based superalloys with coarse grains elongated in the forming direction.
Claims (5)
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19904004471 DE4004471A1 (en) | 1990-02-14 | 1990-02-14 | Heat-treated profiles mfr. esp. for power generation industry |
| DE4004471 | 1990-02-14 | ||
| DE4037827 | 1990-11-28 | ||
| DE19904037827 DE4037827A1 (en) | 1990-02-14 | 1990-11-28 | METHOD FOR PRODUCING HEAT-TREATED PROFILES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP0442545A1 true EP0442545A1 (en) | 1991-08-21 |
Family
ID=25890088
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP91200063A Withdrawn EP0442545A1 (en) | 1990-02-14 | 1991-01-15 | Process for producing heat treated profiles and bodies |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0442545A1 (en) |
| JP (1) | JPH055167A (en) |
| DE (1) | DE4037827A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1993021357A1 (en) * | 1992-04-17 | 1993-10-28 | Owens-Corning Fiberglas Corporation | Dispersion strengthened alloys |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3746581A (en) * | 1972-01-31 | 1973-07-17 | Nat Nickel Co Inc | Zone annealing in dispersion strengthened materials |
| EP0232477A1 (en) * | 1985-12-19 | 1987-08-19 | BBC Brown Boveri AG | Process for zone-annealing of metal workpieces |
| EP0274631A1 (en) * | 1986-12-19 | 1988-07-20 | BBC Brown Boveri AG | Process for increasing the room temperature ductility of an oxide dispersion hardened nickel base superalloy article having a coarse columnar grain structure directionally oriented along the length |
| US4781772A (en) * | 1988-02-22 | 1988-11-01 | Inco Alloys International, Inc. | ODS alloy having intermediate high temperature strength |
| EP0398121A1 (en) * | 1989-05-16 | 1990-11-22 | Asea Brown Boveri Ag | Process for producing coarse columnar grains directionally oriented along their length in an oxide dispersion hardened nickel base superalloy |
-
1990
- 1990-11-28 DE DE19904037827 patent/DE4037827A1/en not_active Withdrawn
-
1991
- 1991-01-15 EP EP91200063A patent/EP0442545A1/en not_active Withdrawn
- 1991-02-14 JP JP4266191A patent/JPH055167A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3746581A (en) * | 1972-01-31 | 1973-07-17 | Nat Nickel Co Inc | Zone annealing in dispersion strengthened materials |
| EP0232477A1 (en) * | 1985-12-19 | 1987-08-19 | BBC Brown Boveri AG | Process for zone-annealing of metal workpieces |
| EP0274631A1 (en) * | 1986-12-19 | 1988-07-20 | BBC Brown Boveri AG | Process for increasing the room temperature ductility of an oxide dispersion hardened nickel base superalloy article having a coarse columnar grain structure directionally oriented along the length |
| US4781772A (en) * | 1988-02-22 | 1988-11-01 | Inco Alloys International, Inc. | ODS alloy having intermediate high temperature strength |
| EP0398121A1 (en) * | 1989-05-16 | 1990-11-22 | Asea Brown Boveri Ag | Process for producing coarse columnar grains directionally oriented along their length in an oxide dispersion hardened nickel base superalloy |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1993021357A1 (en) * | 1992-04-17 | 1993-10-28 | Owens-Corning Fiberglas Corporation | Dispersion strengthened alloys |
Also Published As
| Publication number | Publication date |
|---|---|
| DE4037827A1 (en) | 1992-06-04 |
| JPH055167A (en) | 1993-01-14 |
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