EP0091279B1 - Elément de construction en alliage à base de nickel et procédé pour sa fabrication - Google Patents

Elément de construction en alliage à base de nickel et procédé pour sa fabrication Download PDF

Info

Publication number
EP0091279B1
EP0091279B1 EP83301811A EP83301811A EP0091279B1 EP 0091279 B1 EP0091279 B1 EP 0091279B1 EP 83301811 A EP83301811 A EP 83301811A EP 83301811 A EP83301811 A EP 83301811A EP 0091279 B1 EP0091279 B1 EP 0091279B1
Authority
EP
European Patent Office
Prior art keywords
alloy
subjecting
aging treatment
plastic working
temperature
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.)
Expired
Application number
EP83301811A
Other languages
German (de)
English (en)
Other versions
EP0091279A1 (fr
Inventor
Yoshinao Urayama
Shigeo Hattori
Isao Masaoka
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Publication of EP0091279A1 publication Critical patent/EP0091279A1/fr
Application granted granted Critical
Publication of EP0091279B1 publication Critical patent/EP0091279B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C19/00—Alloys based on nickel or cobalt
    • C22C19/03—Alloys based on nickel or cobalt based on nickel
    • C22C19/05—Alloys based on nickel or cobalt based on nickel with chromium
    • C22C19/058—Alloys based on nickel or cobalt based on nickel with chromium without Mo and W
    • 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 present invention relates to a member made of a Ni-base alloy, particularly a member of a Ni-base alloy in the form of a spring or bolt used in a nuclear reactor, as well as a method of producing the same.
  • springs used in nuclear reactors have been produced by a process which has the steps of forming the spring from a blank, subjecting the formed spring to a solution heat treatment, effecting a cold rolling at a working ratio of 30% and then subjecting the rolled spring to an aging treatment.
  • a process which has the steps of forming the spring from a blank, subjecting the formed spring to a solution heat treatment, effecting a cold rolling at a working ratio of 30% and then subjecting the rolled spring to an aging treatment.
  • sufficiently high mechanical strength at high temperature and a superior spring property both of which are essential requisites for the springs used in nuclear reactors, are ensured by the steps of cold working and subsequent aging treatment.
  • SCC stress corrosion cracking
  • the springs particularly springs for nuclear reactors such as the expansion spring incorporated in the control rod drives of a boiling water reactor (BWR) are often used in places where crevices exist under application of high level of stress. A countermeasure against SCC, therefore, is essential for such springs.
  • the spring blank formed from this material is subjected to a cold working at working ratio of 30 to 40% after having been subjected to a solution heat treatment, and then subjected to a direct aging treatment.
  • the cold working after the solution heat treatment is conducted to give a final shape to the spring.
  • the aging treatment following the cold working contributes to the improvement in the spring property and strength at high temperature essential for the springs used in nuclear reactors.
  • Japanese Patent Application Laid-Open No. 69517/79 mentions the intergranular corrosion in a solid solution hardening alloy but does not mention at all the SCC resistance of a precipitation hardening alloy. Unlike the solid solution hardening alloy, the precipitation hardening alloy does not exhibit any specific relationship between the crevice SCC susceptibility and the intergranular corrosion susceptibility.
  • EP-A-56480 published after the priority date claimed in the present application describes a member made of a Ni-base alloy arid for use exposed to pure water in a nuclear reactor.
  • the alloy has high resistance to stress corrosion cracking and consists of by weight 15 to 25% Cr, 1 to 8% Mo, 0.4 to 2% Al, 0.7 to 3% Ti, 0.7 to 4.5% Nb and balance Ni
  • EP-A-66361 also published after the present priority date discloses a Ni-base alloy resistant to hydrogen embrittlement and chloride stress cracking which contains 15 to 22% Cr, 10 to 28% Fe, 6 to 9% Mo, 2.5 to 5% Nb, 1 to 2%'Ti and up to 1 % Al.
  • an object of the invention is to provide an Ni-base alloy member having superior SCC resistance, as well as a method of producing the same, thereby to overcome or reduce the above-described problems of the prior art.
  • the present inventors have conducted extensive experiments in which the working ratio of the cold working executed between the solution heat treatment and the aging treatment was varied to investigate how the crevice SCC resistance is influenced by the cold working ratio.
  • the approach has been from two aspects: namely, a constant strain test with crevice in pure water of high temperature and pressure and metallographic observation of structure.
  • similar investigation was applied also to the condition of aging treatment (direct aging and two-stepped aging). As a'result, the following facts were newly found by the inventors through the experiments.
  • the alloy of the member produced preferably has a structure containing discontinuous granular precipitate of Cr carbide along the grain boundary or an apparent primary recrystallization structure which precipitates in Eta phase Widman Maschinenn form or in dendritic form.
  • the cold plastic working ratio is preferably in the range between 60 and 70% in terms of reduction of cross-sectional area.
  • the cold plastic working ratio is preferably in the range between 40 and 70% in terms of reduction of cross-sectional area. This process affords an advantage in that the working ratio can be made smaller than that in the process including direct aging.
  • the Cr content should be 14% at the smallest, but any Cr content exceeding 25% degrades the hot workability and, in addition, a noxious phase known as TCP phase is formed to deteriorate the cold workability, mechanical properties and corrosion resistance. From these points of view, the Cr content is preferably in the range between 14 and 25%, more preferably 14 and 20% and most preferably'14 and 17%... '
  • Fe is an element which is effective in stabilizing the structure of the matrix and improving the corrosion resistance.
  • a too large Fe content permits the production of noxious phase such as Laves phase and, therefore, the Fe content is preferably not greater than 30%, more preferably not greater than 10% and most preferably 5 to 9%.
  • Al, Ti and Nb contribute to the precipitation hardening due to formation of intermetallic compounds through reaction with Ni.
  • at least a combination of not smaller than 0.2% of AI and not smaller than 0.5% of Ti is essential. It is possible to obtain alloys of desired high strength by increasing the Al and Ti contents while adding Nb thereto, but the property is degraded if the Al, Ti and Nb contents are increased excessively. Therefore, AI, Ti and Nb contents are preferably 0.2 to 2% 0.5 to 3% and 0.7 to 4.5%, respectively. More preferably, the AI, Ti and Nb contents are 0.4 to 1.0%, 2 to 3% and 0.7 to 1.5%, respectively.
  • Nb has greater effect on the precipitation hardening than AI and Ti and, therefore, the addition of Nb is necessary for obtaining high hardenability required especially for the material of springs and bolts used in nuclear reactors.
  • the Nb content is preferably in the range between 0.5 and 1.5%.
  • the C content should not exceed 0.15% because C content exceeding 0.15% inconveniently lowers the cold plastic workability.
  • the content is preferably in the range between 0.02 and 0.08%.
  • the Si content and Mn content are selected to range between 0.02 and 0.5% and 0.1 and 1%, respectively.
  • the balance of the composition consists substantially of Ni.
  • the Ni content is preferably not smaller than 65%, and more preferably not smaller than 70%.
  • the direct aging treatment is conducted at a temperature in the range between 650 and 750°C.
  • the two-stepped aging treatment is conducted preferably by heating the material to and maintaining the same at 800 to 900°C for 1 to 30 hours, cooling the material and then heating to and maintaining at 600 to 750°C for 1 to 30 hours. It is also preferred that the solution heat treatment is conducted at a temperature ranging between 950 and 1150°C.
  • the members of the Ni-base alloys of the invention are described here particularly in the form of springs and bolts which are subjected to pure water of high pressure and temperature in nuclear reactors.
  • Figs. 1a to 1f illustrate shapes of various springs and bolts used in nuclear reactors. A description will be made hereinafter as to the natures of these springs and bolts, as well as the method of producing these springs and bolts.
  • Figs. 1a and 1 b illustrate an expansion spring 12 which is used for securing graphite seal segments 11 to the inner surface of an index tube 10.
  • the expansion spring 12 has the form of a web-like ring cut at a portion thereof as at 13. The breadth or axial height is 10 mm while the diameter is 60 mm.
  • This expansion ring 12 is made by a process having the steps of preparation of molten alloy material, solidification, rolling, solution heat treatment, cold rolling at a working ratio of 25% or higher, forming and two-stepped aging treatment.
  • Figs. 1c and 1d illustrate a garter spring 22 for securing graphite seal segments 21 to a piston tube 20.
  • the garter spring 22 is a coiled spring having a coil length of 166 mm and formed from a wire of 0.36 mm dia. This garter spring is produced by a process which has the steps of preparation of molten alloy material, solidification, solution heat treatment, drawing, coiling at a working ratio of 25% or higher and two-stepped aging treatment.
  • Fig. 1e shows a spring 32 which is interposed between a tie plate 30 and a channel box 31, while Fig. 1f shows a spring 41 associated with a cap screw 40.
  • These springs 32 and 41 are produced by the same process as the expansion spring shown in Figs. 1a and 1b.
  • a reference numeral 42 designates a guard.
  • the cap screw 40 is produced by a process having the steps of forging or rolling, solution heat treatment, and threading by thread rolling or machining. The aforementioned two-stepped aging treatment is conducted following the threading.
  • Inconel x750 (commercial name) consisting essentially of, by weight, 72.92% of Ni, 15.48% of Cr, 6.91 % of Fe, 0.57% of Al, 2.60% of Ti, 0.95% of Nb+Ta, 0.04% of C, 0.20% of Si and 0.23% of Mn was used as the blank.
  • Table 1 shows the result of a crevice constant strain test conducted in pure water of high temperature and pressure under the following condition.
  • Figs. 2(a) to (d) show the metallographies as obtained through a direct aging treatment when the cold working ratio is 10%, 20%, 30% and 60%, respectively, while Figs.
  • 3(a) to (d) shows those obtained through two-stepped aging treatment when the cold plastic working is conducted at working ratio of 10%, 20%, 30% and 60%, respectively.
  • the aging treatment is conducted through a direct aging, the grains become deformed as the cold working ratio is increased.
  • no specific relationship is observed between the crevice SCC susceptibility and the metallography.
  • the metallographies exhibiting large crevice SCC susceptibility show only intergranular corrosion
  • the metallographies exhibiting small crevice SCC susceptibility show a comparatively large number of apparent primary recrystallization grains, as well as intergranular corrosion.
  • Fig. 4 shows microscopic photos of metallographies of inconel x750 alloy subjected to direct aging treatment and two-stepped aging treatment, after cold plastic working at working ratio of 0%, 30%, and 60%, respectively.
  • the direct aging treatment continuous precipitate of Cr carbide is observed along the grain boundary when the cold plastic working ratio is 0% and 30%. It is, therefore, understood that the low crevice SCC resistance in the alloy cold-worked at such low working ratio is attributable to the continuous precipitate of Cr carbide in the grain boundary.
  • the cold working at a working ratio not smaller than 40% is effective in the production of springs and bolts having superior crevice SCC resistance suitable for use in nuclear reactors, when the aging is conducted through a direct aging treatment, whereas, when the aging is conducted through two-stepped aging treatment, the cold working at a working ratio not smaller than 25% is effective.
  • the crevice SCC resistance can easily be evaluated through the observation of the metallography, i.e. the state of precipitate of Cr carbide and the existence of the apparent primary recrystallization structure.

Landscapes

  • 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)
  • Heat Treatment Of Nonferrous Metals Or Alloys (AREA)

Claims (9)

1. Procédé de fabrication d'un élément constitué d'un alliage à base de nickel ayant une résistance élevée à la fissuration par corrosion sous tension comprenant les étapes consistant: à préparer un alliage constitué, en poids, de pas plus de 0,15% de C, pas plus de 1 % de Si, pas plus de 1,5% de Mn, entre 14 et 25% de Cr, pas plus de 30% de Fe, entre 0.2 et 2% de AI, entre 0,5 et 3% de Ti, entre 0,7 et 4,5% de Nb et le reste en Ni et en impuretés inévitables, la teneur en Ni étant au moins de 65%; à soumettre ledit alliage à un traitement thermique de mise en solution; à effectuer un travail de déformation plastique à froid sur ledit alliage avec une réduction de surface de la section transversale entre 50 et 70%; et à soumettre ledit alliage à un traitement de vieillissement à une température située entre 650 et 750°C.
2. Procédé de fabrication d'un élément constitué d'un alliage à base de nickel ayant une résistance élevée à la fissuration par corrosion sous tension comprenant les étapes consistant: à préparer un alliage constitué, en poids, de 0,02 à 0,08% de C, de 0,02 à 0,5% de Si, de 0,1 à 1 % de Mn, de 14 à 20% de Cr, pas plus de 10% de Fe, de 0,4 à 1 % d'AI, de 2 à 3% de Ti, de 0.7 à 1,5% de Nb et le reste en Ni et en impuretés inévitables, la teneur en Ni étant au moins de 65%; soumettre ledit alliage à un traitement thermique de mise en solution, à effectuer un travail de déformation plastique à froid sur ledit alliage avec une réduction de surface de la section transversale entre 50 et 70%; et à soumettre ledit alliage à un traitement de vieillissement à une température comprise entre 650 et 750°C.
3. Procédé de fabrication d'un élément constitué d'un alliage à base de nickel ayant une résistance élevée à la fissuration par corrosion sous tension comprenant les étapes consistant: à préparer un alliage constitué, en poids, de pas plus de 0,15% de C, pas plus de 1 % de Si, pas plus de 1,5% de Mn, de 14 à 25% de Cr, pas plus de 30% de Fe, de 0,2 à 2% d'AI, de 0,5 à 3% de Ti, de 0.7 à 4,5% de Nb et le reste en Ni et en impuretés inévitables, la teneur en Ni n'étant pas inférieure à 65%; à soumettre ledit alliage à un traitement thermique de mise en solution; à effectuer un travail de déformation plastique à froid sur ledit alliage avec une réduction de surface de la section transversale entre 30 et 70%; à soumettre ledit alliage à un traitement de vieillissement à une température comprise entre 800 et 950°C; et à soumettre ledit alliage à un autre traitement de vieillissement à une température comprise entre 600 et 750°C.
4. Procédé selon la revendication 3, dans lequel ledit travail de déformation plastique à froid est effectué avec une réduction de la surface de la section transversale comprise entre 40 et 70%
5. Procédé de fabrication d'un élément constitué d'un alliage à base de nickel ayant une résistance élevée à la fissuration par corrosion sous tension comprenant les étapes consistant à: préparer un alliage constitué, en poids, de 0,02 à 0,8% de C, 0,02 à 0,5% de Si, de 0,1 à 1 % de Mn, de 14 à 20% de Cr, pas plus de 10% de Fe, de 0,4 à 1% d'AI, de 2 à 3% de Ti, de 0.7 à 1,5% de Nb et le reste en Ni et en impuretés inévitables, la teneur en Ni étant d'au moins 65%; à soumettre ledit alliage à un traitement thermique de mise en solution; à effectuer un travail de déformation plastique à froid sur ledit alliage avec une réduction de la surface de la section transversale qui n'est pas inférieure à 25%; à soumettre ledit alliage à un traitement de vieillissement à une température comprise entre 800 et 950°C; et à soumettre ledit alliage à un autre traitement de vieillissement à une température comprise entre 600 et 750°C.
6. Procédé selon la revendication 5, dans lequel ledit travail de déformation plastique à froid est effectué avec une réduction de la surface de la section transversale comprise entre 40 et 70%.
7. Elément fabriqué en un alliage à base de nickel obtenu par un procédé selon l'une quelconque des revendications précédentes qui a une structure contenant des précipités granulaires discontinus de carbure de Cr le long des limites des grains ou une structure apparente de recristallisation primaire.
8. Utilisation d'un élément fabriqué en alliage à base de nickel obtenu par un procédé selon l'une quelconque des revendications précédentes, comme composant d'un réacteur nucléaire exposé à de l'eau pure à haute température et à haute pression.
9. Utilisation d'un élément fabriqué en alliage à base de nickel selon la revendication 8, sous forme d'un ressort ou d'un boulon exposé à de l'eau pure à haute température et à haute pression dans un réacteur nucléaire.
EP83301811A 1982-04-02 1983-03-30 Elément de construction en alliage à base de nickel et procédé pour sa fabrication Expired EP0091279B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP55780/82 1982-04-02
JP5578082A JPS58174538A (ja) 1982-04-02 1982-04-02 原子炉用隙間構造部材に用いられる耐応力腐食割れ性に優れたＮｉ基合金製部材

Publications (2)

Publication Number Publication Date
EP0091279A1 EP0091279A1 (fr) 1983-10-12
EP0091279B1 true EP0091279B1 (fr) 1986-12-10

Family

ID=13008403

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83301811A Expired EP0091279B1 (fr) 1982-04-02 1983-03-30 Elément de construction en alliage à base de nickel et procédé pour sa fabrication

Country Status (3)

Country Link
EP (1) EP0091279B1 (fr)
JP (1) JPS58174538A (fr)
DE (1) DE3368289D1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104988356A (zh) * 2015-05-27 2015-10-21 钢铁研究总院 一种高纯净度镍基合金大型锻件制备方法

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60204849A (ja) * 1984-03-28 1985-10-16 Toshiba Corp 原子力発電プラント制御棒駆動機構用シ−ルリング
US4626408A (en) * 1984-09-20 1986-12-02 Nippon Yakin Kogyo Kabushiki Kaisha Ni-based alloy excellent in intergranular corrosion resistance, stress corrosion cracking resistance and hot workability
JPH0742560B2 (ja) * 1984-12-14 1995-05-10 株式会社東芝 高温バネの製造方法
JPH0647701B2 (ja) * 1984-12-14 1994-06-22 株式会社東芝 マグネトロンのフイラメントライテイング用電気接続端子クリツプ
JPH0684535B2 (ja) * 1984-12-27 1994-10-26 株式会社東芝 ニッケル基合金の製造方法
US4761190A (en) * 1985-12-11 1988-08-02 Inco Alloys International, Inc. Method of manufacture of a heat resistant alloy useful in heat recuperator applications and product
EP0235075B1 (fr) * 1986-01-20 1992-05-06 Mitsubishi Jukogyo Kabushiki Kaisha Alliage à base de nickel et procédé pour sa fabrication
FR2596066B1 (fr) * 1986-03-18 1994-04-08 Electricite De France Alliage austenitique nickel-chrome-fer
US4793868A (en) * 1986-09-15 1988-12-27 General Electric Company Thermomechanical method of forming fatigue crack resistant nickel base superalloys and product formed
JPS63198316A (ja) * 1987-01-08 1988-08-17 インコ、アロイス、インターナショナルインコーポレーテッド シリコンウェーハ処理用トレー
US4882125A (en) * 1988-04-22 1989-11-21 Inco Alloys International, Inc. Sulfidation/oxidation resistant alloys
US4909860A (en) * 1989-02-21 1990-03-20 Inco Alloys International, Inc. Method for strengthening cold worked nickel-base alloys
US5047093A (en) * 1989-06-09 1991-09-10 The Babcock & Wilcox Company Heat treatment of Alloy 718 for improved stress corrosion cracking resistance
JP4277113B2 (ja) * 2002-02-27 2009-06-10 大同特殊鋼株式会社 耐熱ばね用Ｎｉ基合金
US8197748B2 (en) * 2008-12-18 2012-06-12 Korea Atomic Energy Research Institute Corrosion resistant structural alloy for electrolytic reduction equipment for spent nuclear fuel

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0056480A2 (fr) * 1980-12-24 1982-07-28 Hitachi, Ltd. Application d'un alliage à base de nickel, possédant une résistance élevée à la corrosion fissurante sous tension
EP0066361A2 (fr) * 1981-04-17 1982-12-08 Inco Alloys International, Inc. Alliage à base de nickel, résistant à la corrosion et possédant des caractéristiques mécaniques élevées

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3592632A (en) * 1966-07-14 1971-07-13 Int Nickel Co High temperature nickel-chromium-iron alloys particularly suitable for steam power applications
US3660177A (en) * 1970-05-18 1972-05-02 United Aircraft Corp Processing of nickel-base alloys for improved fatigue properties
FR2277901A2 (fr) * 1974-07-12 1976-02-06 Creusot Loire Perfectionnements aux alliages a base de nickel-fer-chrome, a durcissement structural obtenu par un traitement thermique approprie
US4225363A (en) * 1978-06-22 1980-09-30 The United States Of America As Represented By The United States Department Of Energy Method for heat treating iron-nickel-chromium alloy
JPS5726153A (en) * 1980-07-23 1982-02-12 Toshiba Corp Heat treatment of nickel superalloy

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0056480A2 (fr) * 1980-12-24 1982-07-28 Hitachi, Ltd. Application d'un alliage à base de nickel, possédant une résistance élevée à la corrosion fissurante sous tension
EP0066361A2 (fr) * 1981-04-17 1982-12-08 Inco Alloys International, Inc. Alliage à base de nickel, résistant à la corrosion et possédant des caractéristiques mécaniques élevées

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"Metals Handbook" 9th Ed., Vol. 3, 1980, page 211 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104988356A (zh) * 2015-05-27 2015-10-21 钢铁研究总院 一种高纯净度镍基合金大型锻件制备方法
CN104988356B (zh) * 2015-05-27 2017-03-22 钢铁研究总院 一种高纯净度镍基合金大型锻件制备方法

Also Published As

Publication number Publication date
DE3368289D1 (en) 1987-01-22
EP0091279A1 (fr) 1983-10-12
JPS6211058B2 (fr) 1987-03-10
JPS58174538A (ja) 1983-10-13

Similar Documents

Publication Publication Date Title
EP0091279B1 (fr) Elément de construction en alliage à base de nickel et procédé pour sa fabrication
DE3781798T3 (de) Ferritischer rostfreier Stahl und Verfahren zur Herstellung.
EP2199420B1 (fr) Acier inoxydable austénitique
DE69018658T2 (de) Hochfester hitzebeständiger Stahl mit verbesserter Bearbeitbarkeit.
DE60015728T2 (de) Wärmebeständiger legierungsdraht
DE69126902T2 (de) Austenitischer Stahl mit verbesserten Spannungsrisskorrosionsbeständigkeitscharakteristiken, Verfahren zu seiner Herstellung sowie dessen Verwendung
EP2855724B1 (fr) Alliage nickel-chrome avec bonne formabilité, la résistance au fluage et à la corrosion
DE3650515T2 (de) Hochfester hitzebeständiger ferritischer Stahl mit hohem Chromgehalt
EP2855723B1 (fr) Alliage nickel-chrome-aluminium avec bonne formabilité, la résistance au fluage et à la corrosion
DE69010234T2 (de) Hochfester Stahl mit hohem Chromgehalt und mit sehr guten Zähigkeits- und Oxidationsbeständigkeitseigenschaften.
DE69529829T2 (de) Ferritische wärmebeständige Stähle
EP0056480A2 (fr) Application d'un alliage à base de nickel, possédant une résistance élevée à la corrosion fissurante sous tension
DE69706224T2 (de) Wärmebeständiger Stahl und Dampfturbinenrotor
US4512820A (en) In-pile parts for nuclear reactor and method of heat treatment therefor
EP3158097A2 (fr) Alliage nickel-chrome-molybdène résistant à la corrosion, article manufacturé et procédé de fabrication de ce dernier
US4227925A (en) Heat-resistant alloy for welded structures
GB2173816A (en) Superplastic ferrous duplex-phase alloy and a hot working method therefor
DE68919199T2 (de) Flexibles rohr für den transport eines fluids.
DE2714674B2 (de) Superlegierung mit hoher Dauerfestigkeit
DE2744105A1 (de) Ferritlegierung mit hoher festigkeit
DE69106372T2 (de) Legierung mit niedrigem wärmeausdehnungskoeffizient und daraus hergestellter gegenstand.
DE3416521C2 (fr)
EP0076110B1 (fr) Superalliages, susceptibles de durcissement par vieillissement à l'état martensitique et procédés pour leur traitement thermique
DE69502609T2 (de) Kavitationsbeständige fluidumschaufelräder und verfahren zu deren herstellung
EP0398264B1 (fr) Alliage monocristallin coulé à base de nickel du type durci par précipitation

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): DE FR SE

17P Request for examination filed

Effective date: 19840224

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR SE

REF Corresponds to:

Ref document number: 3368289

Country of ref document: DE

Date of ref document: 19870122

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19940216

Year of fee payment: 12

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19940331

Year of fee payment: 12

EAL Se: european patent in force in sweden

Ref document number: 83301811.2

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19950331

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19951201

EUG Se: european patent has lapsed

Ref document number: 83301811.2

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19981215

Year of fee payment: 17

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20001130

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST