EP0366655B1 - Compositions d'alliages a base de fer resistantes a l'oxydation - Google Patents

Compositions d'alliages a base de fer resistantes a l'oxydation Download PDF

Info

Publication number
EP0366655B1
EP0366655B1 EP88903643A EP88903643A EP0366655B1 EP 0366655 B1 EP0366655 B1 EP 0366655B1 EP 88903643 A EP88903643 A EP 88903643A EP 88903643 A EP88903643 A EP 88903643A EP 0366655 B1 EP0366655 B1 EP 0366655B1
Authority
EP
European Patent Office
Prior art keywords
alloy
weight
alloys
elements
nickel
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 - Lifetime
Application number
EP88903643A
Other languages
German (de)
English (en)
Other versions
EP0366655A4 (en
EP0366655A1 (fr
Inventor
John M. Corwin
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.)
Chrysler Motors Corp
Original Assignee
Chrysler Motors Corp
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 Chrysler Motors Corp filed Critical Chrysler Motors Corp
Publication of EP0366655A1 publication Critical patent/EP0366655A1/fr
Publication of EP0366655A4 publication Critical patent/EP0366655A4/en
Application granted granted Critical
Publication of EP0366655B1 publication Critical patent/EP0366655B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • C22C38/00—Ferrous alloys, e.g. steel alloys

Definitions

  • This invention relates to iron-base alloy compositions.
  • the compositions relate to nickel containing austenitic ferrous alloy compositions, especially low nickel compositions.
  • this invention relates to dopants added to low nickel austenitic alloys as a means of improving the elevated temperature oxidation resistance. This invention may be extended to apply to cast alloys.
  • sheet metal automotive exhaust system parts would offer the advantages of both lighter weight and reduced thermal mass.
  • the metal thickness of wrought automotive engine parts such as thermal reactors and turbocharger housings, should be minimized. This can be accomplished by constructing the engine parts from stainless steels, austenitic where hot strength is required, and with alloying suitable for resistance to deterioration by engine exhaust gases on the inside surface of the engine parts and atmospheric air on the outside surface of the engine parts where the surface operating temperature is at a maximum.
  • Such a construction is not cost effective because the resistance to oxidation of the lower cost stainless steel sheet metal alloys at elevated temperatures of 815.6°C to 1204.4°C (1,500 degrees F to 2,200 degrees F)is not sufficient to allow their use in applications where the alloy is exposed to the combustion products normally formed by gasoline fueled internal combustion engines. Because the presently available low-cost alloys do not resist oxidation in elevated temperature combustion environments, it is necessary to use a more expensive alloy with a higher nickel and/or chromium content in automotive emission control devices such as thermal reactors. Therefore, the limitation to using currently available, adequate alloy content stainless steels is the high cost and excessive strategic element content.
  • Degradation of alloy materials, such as stainless steels, at elevated temperatures is largely dependent on the protective capacity of surface oxide films formed from the alloy during exposure to heat in oxygen containing atmospheres.
  • the SU-A-553 304 teaches an iron-base alloy composition containing Ca, Mg and Y wherein the amounts of Ca and Mg are in the ranges of 0.001-0.08 and 0.001-0.05 % by weight, respectively. Y added as a dopant element is used in amounts of 0.001-0.1 % by weight.
  • the object of the invention is to provide an iron-base alloy composition which has especially good and significant and reproducible characteristics with regard to one or more oxidation resistant properties of the final composition.
  • compositions of the present invention relate to the discovery that certain elements can be added to iron-base alloy materials to dramatically improve their resistance to oxidation. More particularly, the invention relates to the discovery that the addition of these elements (referred to herein as "dopants") yields lower cost materials suitable for use in heretofore impractical environments.
  • the compositions of the present invention comprise iron-base alloy compositions exhibiting improved resistance to oxidation comprising the components according to patent claim 1.
  • alloy materials such as low nickel austenitic (LNA) stainless steel alloys containing chromium and ferritic stainless steel alloys containing medium to high levels of chromium with the additions of the dopants or doping elements or alloys disclosed herein.
  • Alloy compositions of the present invention would be made in a conventional manner, i.e., typical of the alloy content without the dopant of the present invention, but with provision for the addition of dopant elements, in the melt process or later, in later alloy processing, or by surface treatment.
  • compositions disclosed herein contain small quantities of elements (appearing for the most part in Groups LA, ILA, and IIB of the Periodic Table of Elements) to the base alloy composition. These elements, as ions, enter into the protective oxide scale and modify predominantly anion and to a lesser extent cation transport through the oxide scale, greatly reducing the amount of oxidation observed due to elevated temperature exposure.
  • Austenite Stabilizers Alloys of this invention are designed to maintain a stable austenitic matrix at use temperatures up to 1204°C (2200 degrees F). Elements identified as promoting this austenite stability are Mn, Co, Ni, Cu, C, Sn, Sb, Bi and N. Throughout the course of this alloy development, it was necessary to periodically adjust the choice and quantity of austenite stabilizer elements to balance the counteracting effects of La-Ce, Ti, Zr, V, Cr, Al and Si as these elements were introduced or changed in concentration as part of the effort to determine their effect on oxidation resistance.
  • An object of this invention is to improve the protective nature of surface oxides formed during exposure to elevated temperatures and, therefore, a stable surface oxide is required.
  • Elements identified as significant contributors to stable surface oxide formation on these iron base alloys are: Cr, Co, Ni, Al and Si.
  • the elements Cr, Co and Ni were, individually or in combination, part of the base composition, Table II, and therefore not subject to evaluation during the fractional factorial phase of this investigation.
  • Al and Si were incorporated into the initial experimental design (Table I) and were determined to contribute to improved oxidation resistance through interaction with dopant elements. This interaction is interpreted to be due to the contribution of Al and Si in formation of stable surface oxides.
  • Dopants are elements found to have a major effect on the protective nature of the host oxide. Typically, they are found in groups IA, IIA and IIIB of the Periodic Table of Elements and include, without limitation, those described herein, as well as mixtures of these materials. Their function in improving oxidation resistance is judged to be due to their effect on predominantly anion and to a lesser extent cation transport through the surface oxide film.
  • compositions according to the present invention demonstrate many advantages over art-disclosed compositions including, without limitation, excellent strength; amenability to mass production techniques such as forming, joining and the like; and excellent resistance to oxidation under extreme conditions such as high temperatures.
  • compositions of the present invention relate to the discovery that certain elements can be added to iron-base alloy materials to dramatically improve their resistance to oxidation. More particularly, the invention relates to the discovery that the addition of these elements (referred to herein as "dopants") yields materials suitable for use in heretofore impractical environments thereby avoiding the use of expensive, higher alloy-content materials.
  • iron-base is meant that iron is the predominate alloy element present, by weight of the final composition.
  • iron may be present at a level greater than any other single element by weight.
  • Iron need not comprise 50 percent of the composition; by way of illustration (without limitation), a composition comprising 30 percent iron, by weight, and 29 percent nickel by weight, as well as other elements each being less than 30 percent by weight, but in aggregate totaling more than 50 percent by weight (including the nickel), would be iron-base as defined herein.
  • Preferred alloy elements include those selected from the group consisting of silicon, nickel, chromium, cobalt, manganese, nitrogen, and mixtures thereof. Silicon, nickel, and chromium are particularly preferred.
  • Iron as well as the alloy elements described above, can be employed at levels generally known in the art.
  • the dopants of the present invention may be employed in AISI types 201, 202, 301, 302, 302B, 303, 303Se, 304, 304L, 305, 308, 309, 309S, 310, 315, 316, 316L, 317, 321, 347, 348, 384 and 385 austentic stainless steels.
  • Employing the dopants of the present invention, in addition to the elements at levels conventionally employed (except for small modifications to maintain matrix stability, if needed) in such AISI materials produces materials which can then be employed in heretofore impossible or impractical environments or applications.
  • compositions according to the present invention can also employ lower levels of strategic or expensive elements than generally disclosed in the art, but at the same time demonstrating equivalent or improved oxidation resistant properties.
  • Stainless steel (RA 333) and non-stainless steel (INCO 330) may also employ the dopants of the present invention.
  • Preferred compositions include those where nickel is present at a level of about 5 to about 15 percent, and where chromium is present at a level of about 10 to about 30 percent, by weight of the final composition.
  • aluminum can play many roles in the compositions of the present invention. It can be used as an effective dopant when emploved a: levels below that at which it acts as a bulk oxide former.
  • an alloy of this invention would be made with about 20 to 30 percent by weight chromium, about 0.1 to 1.5 percent by weight carbon, about 3 to 4 percent by weight manganese, about 0 to 12 percent by weight cobalt, about 5 to 15 percent by weight nickel and about 0.5 to 2 percent by weight dopant, with the balance being iron and normal residual impurities.
  • the alloys of this invention can be described as oxidation resistance steels having iron as the base material with the addition of chromium and other alloying elements to increase oxidation resistance.
  • the preferred alloys of this invention have a stable austenitic structure with the further feature that they contain minor quantities of dopant elements.
  • Nickel, cobalt, nitrogen, carbon and manganese are strong austenite stabilizers in ferrous alloys and the concentration of one or more of these elements in the alloy should be maintained at a level high enough to ensure that the alloy's structure remains austenitic over the temperature range normally encountered by parts formed from the alloy.
  • Alloying element ranges of 3 to 4 percent by weight, manganese; 5 to 15 percent by weight, nickel; 0 to 12 percent by weight, cobalt; 0.1 to 0.5 percent by weight, nitrogen; and 0.5 to 1.5 percent by weight, carbon provide good austenite stabilizing levels in normal ferrous alloys.
  • Heat sizes were either 2500 or 5000 grams with resulting ingots weighing approximately 1800 grams. These ingots were hot forged and/or hot rolled into slabs with sufficient thermal-mechanical working to destroy the original cast microstructure. Hot and cold rolling, with inter-stage annealing was employed to produce final strip form, typically 0.030" thick. Special melting procedures were employed for the addition of Mg wherein Mg metal or NiMg was encased in iron foil and plunged into the melt to facilitate high recovery levels of Mg. For convenience, halogen salts of Li, Na, K, Mg, Ca were often employed for small quantity (less than 1 percent) additions of these elements.
  • the magnesium dopant modified silicon-containing alloys show an average oxidation resistance improvement at 1204°C (2,200 degrees F) of 24 percent compared to the undoped base composition. Further addition of calcium dopant yields a 36 percent improvement compared to the undoped base composition.
  • Introduction of Sodium, lithium, potassium, dopants, in addition to magnesium and calcium results in an average oxidation resistance improvement at 1204°C (2,200 degrees F) of 78 percent compared to the undoped base composition.
  • Procedures used to evaluate experimental and commercial alloys range from simple still air cyclic oxidation tests with small coupons in laboratory furnaces, to vehicle tests with full size components.
  • several of the following tests were performed: still-air cyclic oxidation in laboratory furnaces; cyclic endurance tests on engines loaded by dynamometers; controlled exhaust environment tests in tube furnaces; component endurance tests on engines loaded by dynamometers; and on-vehicle tests at the proving grounds for durability.
  • Weight change data by itself can be quite misleading when comparing several different alloys if the mode of corrosive attack is not similar in each case.
  • Metallography was used in most cases to supplement weight change data. Photomicrographs, therefore, are required to illustrate the point.
  • Fig. 1 shown are graphs of the still-air cyclic oxidation resistance of LNA with other commercial high-temperature alloys at 1204°C (2200 degrees F),
  • the LNA alloy outperforms the stainless steel (RA 333) and non-stainless steel (INCO 330) samples (commercial high nickel alloys marketed by Rolled Alloys and International Nickel, respectively) in exhibiting the least weight change over the cycles of testing.
  • alloy test rings were utilized in various segments of an engine/dynamometer installation. Also employed were experimental alloy liners on exhaust manifolds of the engine driving the dynamometer.
  • Fig. 3 is a schematic drawing of the alloy test ring pipe arrangement. The test conditions were controlled readily by injecting air at strategic points in the manifold, and adjusting carburetor jets to produce desired carbon monoxide levels and robot control of engine speed, load, spark and air injection.
  • Mg, Ca, Li, Na and K are the active ingredients in this dopant concept
  • other elements sucn as Y, Si and Al have shown second order interaction benefits with the dopants. While not intending to be bound by theory, this is thought to be due to their contribution to the formation of a stable host oxide along with the other active oxide formers such as chromium, nickel and iron.
  • Both Al and Si are strong ferrite formers and their presence required the further addition of nitrogen as an austenitic stabilizer to maintain the required austenitic microstructure. Accordingly, aluminum can be effective as a dopant when employed at levels below those typically taught in the art and necessary to employ it as an oxide former.
  • Fig. 7 illustrates the progressive improvement in cyclic oxidation resistance of the alloys of this invention as additional dopant elements were introduced.
  • the final low nickel austenitic alloy, with oxidation resistance superior to commercial RA333 contained dopants from the group of elements Li, Na, K, Mg, Ca, Ba and La, all of which are found in Groups IA, IIA or IIIB of the Periodic Table of Elements.
  • Fig. 7 summarizes the experimental-design development of these alloys.
  • oxidation resistance is generally characterized by weight loss per unit area of a 0.030" thick test panel shown as the ordinate.
  • the band “RA333” represents a common commercial oxidation resistant austenitic alloy used as the standard of reference in all oxidation tests.
  • Tabulated along the abscissa are two rows of element designations.
  • the "investigated” row identifies those elements selected by the fractional factorial experiment to be of potential interest and worthy of incorporation into detailed full factorial experimental schemes.
  • the "accepted” row identifies those elements which were found to offer significant improvements in oxidation resistance following detailed analysis of full factorial experiments. Moving from left to right on Fig.

Abstract

La présente invention se rapporte à des compositions d'alliages à base de fer, à une composition d'alliage ferreux osténitique contenant du nickel (en particulier des compositions à faible teneur en nickel) et à des dopants ajoutés à des alliages osténitiques à faible teneur en nickel comme moyens d'améliorer la résistance à l'oxydation à température élevée du matériau qui en résulte. L'oxydation cyclique en air tranquille d'une telle composition d'alliage et une comparaison d'un tel alliage avec deux alliages de la technique antérieure sont représentées sur le graphique.

Claims (4)

  1. Une composition d'alliage à base de fer présentant une résistance améliorée à l'oxydation, comprenant
    (i) du fer ;
    (ii) au moins un élément d'alliage choisi dans le groupe formé par le nickel, le chrome, le molybdène, le manganèse, le silicium, le carbone, le vanadium, le cobalt, le cuivre, l'azote, l'aluminium, le titane, le zirconium et les mélanges de ces éléments ;
    (iii) du magnésium présent en tant qu'élément dopant en une proportion de 0,1 à 1,5 % en poids de la composition finale ;
    (iv) du calcium présent en tant qu'élément dopant en une proportion de 0,1 à 1,5 % en poids de la composition finale ;
    (v) du lithium présent en tant qu'élément dopant en une proportion de 0,1 à O,5 % en poids de la composition finale ;
    (vi) du sodium présent en tant qu'élément dopant en une proportion de 0,1 à 0,5 % en poids de la composition finale ; et
    (vii) du potassium présent en tant qu'élément dopant en une proportion de 0,5 à 1,0 % en poids de la composition finale.
  2. La composition selon la revendication 1 dans laquelle l'élément d'alliage est choisi dans le groupe formé par le silicium, le nickel, le chrome, le cobalt, le manganèse, l'azote et les mélanges de ces éléments.
  3. La composition selon la revendication 2 dans laquelle le nickel est présent en une proportion de 5 à 15 % en poids de la composition finale.
  4. La composition selon la revendication 2 dans laquelle du chrome est présent en une proportion de 10 à 30 % en poids de la composition finale.
EP88903643A 1988-04-04 1988-04-04 Compositions d'alliages a base de fer resistantes a l'oxydation Expired - Lifetime EP0366655B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
PCT/US1988/000982 WO1989009843A1 (fr) 1988-04-04 1988-04-04 Compositions d'alliages a base de fer resistantes a l'oxydation
CA000563292A CA1340700C (fr) 1988-04-04 1988-04-05 Compositions d'alliages a base de fer, resistant a l'oxydation

Publications (3)

Publication Number Publication Date
EP0366655A1 EP0366655A1 (fr) 1990-05-09
EP0366655A4 EP0366655A4 (en) 1991-07-24
EP0366655B1 true EP0366655B1 (fr) 1996-02-28

Family

ID=33565659

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88903643A Expired - Lifetime EP0366655B1 (fr) 1988-04-04 1988-04-04 Compositions d'alliages a base de fer resistantes a l'oxydation

Country Status (4)

Country Link
EP (1) EP0366655B1 (fr)
CA (1) CA1340700C (fr)
DE (1) DE3855047T2 (fr)
WO (1) WO1989009843A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107326293A (zh) * 2017-06-02 2017-11-07 太仓市龙华塑胶有限公司 一种耐磨五金件

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE516583C2 (sv) * 1997-12-05 2002-01-29 Sandvik Ab Austenitiskt rostfritt stål med god oxidationsbeständighet
AUPP042597A0 (en) * 1997-11-17 1997-12-11 Ceramic Fuel Cells Limited A heat resistant steel
DE102008005803A1 (de) * 2008-01-17 2009-07-23 Technische Universität Bergakademie Freiberg Bauteil aus höher kohlnstoffhaltigem austenitischem Stahlformguss, Verfahren zu deren Herstellung und deren Verwendung
CN104032220B (zh) * 2014-05-09 2016-05-25 无锡市华尔泰机械制造有限公司 一种高压临氢工况用法兰
US10316694B2 (en) 2014-07-31 2019-06-11 Garrett Transportation I Inc. Stainless steel alloys, turbocharger turbine housings formed from the stainless steel alloys, and methods for manufacturing the same
US9534281B2 (en) 2014-07-31 2017-01-03 Honeywell International Inc. Turbocharger turbine housings formed from the stainless steel alloys, and methods for manufacturing the same
US9896752B2 (en) 2014-07-31 2018-02-20 Honeywell International Inc. Stainless steel alloys, turbocharger turbine housings formed from the stainless steel alloys, and methods for manufacturing the same
DE102016005531A1 (de) * 2016-05-02 2017-11-02 Vladimir Volchkov Niedriggekohlter Stahl

Family Cites Families (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US648428A (en) * 1898-10-01 1900-05-01 Joseph Patrick Alloy.
US1653630A (en) * 1922-02-25 1927-12-27 Matthew G Collins Alloy
GB629859A (en) * 1940-12-03 1949-09-29 Egon Herbert Schwarz Heat and acid resisting iron alloy
GB803942A (en) * 1956-05-04 1958-11-05 Consett Iron Company Ltd Improvements in or relating to mild steel
US3017265A (en) * 1959-09-25 1962-01-16 Gen Electric Oxidation resistant iron-chromium alloy
SU212541A1 (ru) * 1966-09-05 1968-02-29 А. Л. Сотниченко , В. С. Ярковой Коррозионностойкая сталь
US3591371A (en) * 1968-11-04 1971-07-06 Cabot Corp Cobalt base oxidation resistant alloy
US3730779A (en) * 1970-08-25 1973-05-01 E Caule Oxidation resistant iron base alloy
US3676085A (en) * 1971-02-18 1972-07-11 United Aircraft Corp Cobalt base coating for the superalloys
BE787254A (fr) * 1971-08-06 1973-02-05 Wiggin & Co Ltd Henry Alliages de nickel-chrome
DE2161954A1 (de) * 1971-12-14 1973-06-20 Deutsche Edelstahlwerke Gmbh Ferritischer hitzebestaendiger stahl
JPS5631345B2 (fr) * 1972-01-27 1981-07-21
SU430186A1 (ru) * 1972-11-29 1974-05-30 М. Д. Цкитишвили , Ф. Н. Тавадзе Институт металлургии Грузинской ССР Коррозионностойкая сталь
SU441343A1 (ru) * 1973-02-07 1974-08-30 Центральный Научно-Исследовательский Институт Технологии Машиностроения Жаростойка сталь
SU475414A1 (ru) * 1973-12-06 1975-06-30 Центральный Научно-Исследовательский Институт Технологии Машиностроения Нержавеюща сталь
SU494429A1 (ru) * 1974-04-17 1975-12-05 Научно-Исследовательский И Опытноконструкторский Институт Автоматизации Черной Металлургии Жаростойка сталь
US4022587A (en) * 1974-04-24 1977-05-10 Cabot Corporation Protective nickel base alloy coatings
SU500288A1 (ru) * 1974-07-23 1976-01-25 Запорожский машиностроительный институт им.В.Я.Чубаря Коррозионностойка сталь
US4053308A (en) * 1974-12-24 1977-10-11 Howmedica, Inc. Nonprecious alloy for fusion to porcelain
SU589281A1 (ru) * 1975-03-27 1978-01-25 Центральный Научно-Исследовательский Институт Технологии Машиностроения Жаростойка сталь
SU553304A1 (ru) * 1975-07-11 1977-04-05 Институт Проблем Литья Ан Украинской Сср Сплав на основе железа
SU567769A1 (ru) * 1976-04-19 1977-08-05 Предприятие П/Я А-7476 Сталь
US4157923A (en) * 1976-09-13 1979-06-12 Ford Motor Company Surface alloying and heat treating processes
USRE31339E (en) * 1977-08-03 1983-08-09 Howmet Turbine Components Corporation Process for producing elevated temperature corrosion resistant metal articles
US4159908A (en) * 1978-08-14 1979-07-03 N L Industries, Inc. Alkali metal containing battery grid lead alloy
GB2036793B (en) * 1978-12-02 1983-11-16 Pells A Nickl or nickelcobalt base alloys with corrosion resistance
US4388125A (en) * 1981-01-13 1983-06-14 The International Nickel Company, Inc. Carburization resistant high temperature alloy
US4400211A (en) * 1981-06-10 1983-08-23 Sumitomo Metal Industries, Ltd. Alloy for making high strength deep well casing and tubing having improved resistance to stress-corrosion cracking
US4400209A (en) * 1981-06-10 1983-08-23 Sumitomo Metal Industries, Ltd. Alloy for making high strength deep well casing and tubing having improved resistance to stress-corrosion cracking
EP0107334B1 (fr) * 1982-10-05 1986-12-03 The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Alliages d'aluminium
US4572750A (en) * 1983-07-21 1986-02-25 The Foundation: The Research Institute Of Electric And Magnetic Alloys Magnetic alloy for magnetic recording-reproducing head
US4600556A (en) * 1983-08-08 1986-07-15 Inco Alloys International, Inc. Dispersion strengthened mechanically alloyed Al-Mg-Li
ATE56475T1 (de) * 1984-11-05 1990-09-15 Extramet Sa Verfahren zum behandeln, insbesondere zum feinen von metallen und legierungen.
US4612166A (en) * 1985-10-15 1986-09-16 Olin Corporation Copper-silicon-tin alloys having improved cleanability

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107326293A (zh) * 2017-06-02 2017-11-07 太仓市龙华塑胶有限公司 一种耐磨五金件

Also Published As

Publication number Publication date
CA1340700C (fr) 1999-08-10
WO1989009843A1 (fr) 1989-10-19
DE3855047T2 (de) 1996-09-12
DE3855047D1 (de) 1996-04-04
EP0366655A4 (en) 1991-07-24
EP0366655A1 (fr) 1990-05-09

Similar Documents

Publication Publication Date Title
EP0478790B1 (fr) Acier inoxydable ferritique thermo-resistant presentant d'excellentes proprietes de tenacite a basse temperature, de soudabilite et de thermo-resistance
JP5600012B2 (ja) 耐酸化性及び耐二次加工脆性に優れたフェライト系ステンレス鋼、並びに鋼材及び二次加工品
EP0376943B1 (fr) Procede de preparation de compositions d'alliages a base de fer resistantes a l'oxydation
EP0366655B1 (fr) Compositions d'alliages a base de fer resistantes a l'oxydation
US20210115536A1 (en) Use of a nickel-chromium-iron-aluminum alloy
US4224062A (en) High temperature creep resistant structural steel
US4999158A (en) Oxidation resistant iron base alloy compositions
GB2158460A (en) Alloys for exhaust valves
US5130085A (en) High al austenitic heat-resistant steel superior in hot workability
US4102225A (en) Low chromium oxidation resistant austenitic stainless steel
EP0678587A1 (fr) Acier ferritique laminé à chaud pour un dispositif d'échappement d'un véhicule à moteur
EP0956372B1 (fr) Acier austenitique inoxydable et utilisation de cet acier
US5427634A (en) Ferrite system stainless steel having excellent nacl-induced hot corrosion resistance and high temperature strength
EP0359085A1 (fr) Aciers de coulée, résistant aux températures élevées
US4141724A (en) Low-cost, high temperature oxidation-resistant steel
US3459538A (en) Corrosion resistant low-alloy steel
US20230002861A1 (en) Nickel-chromium-iron-aluminum alloy having good processability, creep resistance and corrosion resistance, and use thereof
Mayuzumi et al. Corrosion behavior of high-purity Fe-Cr-Ni alloys in the transpassive condition
Sikka Intermetallic-based high-temperature materials
KR100188555B1 (ko) 니켈 합금
CA1326141C (fr) Alliage resistant a la sulfuration
US11667995B2 (en) Cast iron alloy for automotive engine applications with superior high temperature oxidation properties
JP2820255B2 (ja) 熱間加工性の優れた高ａ１オーステナイト系耐熱鋼
SU836195A1 (ru) Сталь
JP3381457B2 (ja) 溶接性に優れた高温用オーステナイト系ステンレス鋼

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

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

17P Request for examination filed

Effective date: 19900326

A4 Supplementary search report drawn up and despatched

Effective date: 19910606

AK Designated contracting states

Kind code of ref document: A4

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

RBV Designated contracting states (corrected)

Designated state(s): DE FR GB SE

17Q First examination report despatched

Effective date: 19920904

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB SE

REF Corresponds to:

Ref document number: 3855047

Country of ref document: DE

Date of ref document: 19960404

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: GB

Payment date: 20010315

Year of fee payment: 14

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

Ref country code: FR

Payment date: 20010328

Year of fee payment: 14

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

Ref country code: SE

Payment date: 20010402

Year of fee payment: 14

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

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

Ref country code: GB

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

Effective date: 20020404

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

Ref country code: SE

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

Effective date: 20020405

EUG Se: european patent has lapsed

Ref document number: 88903643.0

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20020404

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: 20021231

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

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

Ref country code: DE

Payment date: 20030321

Year of fee payment: 16

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

Ref country code: DE

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

Effective date: 20041103