EP0035369A1 - Ferritic iron-aluminium-chromium alloys - Google Patents
Ferritic iron-aluminium-chromium alloys Download PDFInfo
- Publication number
- EP0035369A1 EP0035369A1 EP81300793A EP81300793A EP0035369A1 EP 0035369 A1 EP0035369 A1 EP 0035369A1 EP 81300793 A EP81300793 A EP 81300793A EP 81300793 A EP81300793 A EP 81300793A EP 0035369 A1 EP0035369 A1 EP 0035369A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- aluminium
- chromium
- iron
- alloys
- alloy
- 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.)
- Granted
Links
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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
Definitions
- the present invention relates to ferritic alloys of iron, chromium and aluminium containing a significant amount of hafnium.
- Ferritic iron-chromium-aluminium alloys are known and are in use particularly in environment where resistance to oxidation is of importance. We have found that the oxidation resistance of these alloys and particularly their resistance to oxidation in the presence of sulphur and oxygen, as may be encountered in combustion atmospheres, can be greatly enhanced by small additions of hafnium.
- the present invention provides a ferritic alloy of iron, chromium and aluminium containing:-
- the alloys contain 15.5 to 25% chromium and 4.5 to 10% aluminium.
- the alloys contain from 15.5 to 18% chromium.
- the alloys contain from 4.5 to 6% aluminium e.g. about 5%.
- the percentage of nickel is chosen so that it is not so great within the range quoted above as to produce significant amounts of a second phase taking into account the amounts chosen for each of the other ingredients of the alloy.
- the amount of nickel does not exceed 0.5%.
- rare earth metals may be used in addition to hafnium, e.g. yttrium, zirconium in an amount up to 2% or more preferably in an amount up to 1% or the commercially available alloy known as mischmetall in an amount up to 1%.
- hafnium e.g. yttrium, zirconium
- mischmetall in an amount up to 1%
- the principal ingredients of mischmetall, cerium and lanthanum may be used individually if desired.
- the alloys may be manufactured by the processes normally used for making alloys of this general type.
- the alloys may be made by induction melting, either in air or using inert atmosphere or vacuum as appropriate, cast into ingots and subsequently forged or rolled into billet or slab prior to working down to strip, bar, wire or any other commercially saleable form.
- a charge of high purity iron and low carbon ferrochromium is melted down in a basic lined induction furnace, either in air under a basic slag, or under an inert atmosphere or in vacuo, without slag, as is appropriate.
- a basic lined induction furnace either in air under a basic slag, or under an inert atmosphere or in vacuo, without slag, as is appropriate.
- the appropriate additions of aluminium, ferrotitanium and hafnium metal are added, in that order, the metal brought to temperature and cast into an appropriate ingot mould.
- melt was 10 kg. giving a 2b" (60 mm) sq ingot. This was then heated to about 1100°C and forged under a 10 cwt hammer to produce suitable test bar.
- alloys not in accordance with the invention were prepared having the compositions shown below.
- the test was of relatively short duration but involved cycling between ambient and test temperature.
- the test chamber was an alumina tube 2" (50 mm) internal diameter in which the sample was positioned across an open ended alumina boat. Heating was by means of the concentric electric furnace, the temperature being measured by reference to a noble metal thermo-couple, the hot junction of which was immediately above the specimen.
- the test atmosphere was produced by burning natural gas using excess air over that required for combustion, the flow rates being 1.4 cubic foot and 1.14 cubic foot (0.04 and 0.4 cubic metres) per hour respectively for gas and air.
- the combustion product, a mixture of nitrogen, oxygen r carbon dioxide and steam was pre-heated to test temperature before passing through the test chamber; test temperature was established prior to inserting the sample so that heating was rapid.
- test cycle was for six hours, after which the specimens were removed from the test chamber and cooled in a closed container so that any oxide scale which became detached was collected. When cold, the specimen was weighed, together with any detached scale and then scrubbed with a stiff bristle brush to remove any loosely adhering oxide prior to re-weighing to get the starting weight for the next cycle. The whole procedure was repeated for a total of seven cycles and the total gain in weight, that is the sum of the individual gains, expressed as milligrams per square centimetre, for the 42 hour period, using the original surface area for the untested specimen, was taken as the scaling index.
- Samples A to C are in accordance with the invention but do not exemplify its most preferred embodiments. It can be seen that the scaling index of A at 1200°C is considerably improved over that of comparative Sample 1 and is still superior to that of comparative Sample 2 despite this latter containing much higher amounts of chromium and aluminium. The scaling index of Samples A to C is quite high however at 1250°C. Examples D to K which contain above 4.5% Al and 15.0% Cr show the still more superior characteristics of steels in accordance with the preferred practice of the invention and it can be seen that low scaling indexes are found even at 1250 0 C.
- titanium appears to confer a much smaller but still significant benefit in increased oxidation resistance to the steel containing hafnium. More significantly, the addition of titanium has a substantial effect in reducung the as-cast grain size of the steel and hence greatly improves its hot- working properties. In particular, it was observed that the cast structure of titanium-containing alloys such as B differed from that of alloys A and 2. It was noted that the addition of titanium appeared to have a marked effect on the crystallisation pattern, modifying the coarse columnar crystals of the normal product and giving a more uniform crystal distribution across the section.
- Suitable fields of application for steels according to the invention are those in which resistance to oxidation at high temperatures is required. Examples of such uses are in the provision of electric furnace winding material or resistance heating wire generally and in the provision of knitted wire catalyst supports e.g. for use in vehicle exhaust systems for reducing emissions. Another field in which such properties are of value is in the construction of furnaces, for instance fluid bed combustion furnaces.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Catalysts (AREA)
Abstract
- 10 to 25% chromium
- 1 to 10% aluminium
- 0 to 0.15% carbon
- 0 to 3% silicon
- 0 to 2% manganese
- 0 to 2% titanium
- 0 to 5% nickel, the nickel content not however being so great as to produce significant amounts of a second phase,
- hafnium, 0.05 to 1%
- the balance being iron and incidental amounts of the other alloying elements.
Description
- The present invention relates to ferritic alloys of iron, chromium and aluminium containing a significant amount of hafnium.
- Ferritic iron-chromium-aluminium alloys are known and are in use particularly in environment where resistance to oxidation is of importance. We have found that the oxidation resistance of these alloys and particularly their resistance to oxidation in the presence of sulphur and oxygen, as may be encountered in combustion atmospheres, can be greatly enhanced by small additions of hafnium.
- Accordingly, the present invention provides a ferritic alloy of iron, chromium and aluminium containing:-
- 10 to 25% chromium
- 1 to 10% aluminium
- 0 to 0.15% carbon
- O to 3% silicon
- O to 2% manganese
- O to 5% nickel, the nickel content not however being so great as to produce significant amounts of a second phase,
- O to 2% titanium, and from 0.5 to 1% hafnium, the balance being iron and incidental amounts of other alloying elements.
- Preferably the alloys contain 15.5 to 25% chromium and 4.5 to 10% aluminium.
- Preferably the alloys contain from 15.5 to 18% chromium.
- Preferably the alloys contain from 4.5 to 6% aluminium e.g. about 5%.
- The percentage of nickel is chosen so that it is not so great within the range quoted above as to produce significant amounts of a second phase taking into account the amounts chosen for each of the other ingredients of the alloy. Preferably, the amount of nickel does not exceed 0.5%.
- Other rare earth metals may be used in addition to hafnium, e.g. yttrium, zirconium in an amount up to 2% or more preferably in an amount up to 1% or the commercially available alloy known as mischmetall in an amount up to 1%. Naturally, the principal ingredients of mischmetall, cerium and lanthanum, may be used individually if desired.
- The presence of incidental amounts of molybdenum, copper, tungsten and cobalt above the impurity level can be tolerated provided these elements are not present in excess. Other elements such as sulphur, phosphorus and vanadium may be present as impurities but are not desirable.
- The alloys may be manufactured by the processes normally used for making alloys of this general type. For instance, the alloys may be made by induction melting, either in air or using inert atmosphere or vacuum as appropriate, cast into ingots and subsequently forged or rolled into billet or slab prior to working down to strip, bar, wire or any other commercially saleable form.
- In a typical small scale process for producing an iron-chromium-aluminium steel of the invention, a charge of high purity iron and low carbon ferrochromium is melted down in a basic lined induction furnace, either in air under a basic slag, or under an inert atmosphere or in vacuo, without slag, as is appropriate. When completely melted, the appropriate additions of aluminium, ferrotitanium and hafnium metal are added, in that order, the metal brought to temperature and cast into an appropriate ingot mould.
- The invention will be illustrated by the following examples. Alloys according to the invention were prepared having the compositions shown below by the process described above.
- The size of melt was 10 kg. giving a 2b" (60 mm) sq ingot. This was then heated to about 1100°C and forged under a 10 cwt hammer to produce suitable test bar. For the purpose of comparison, alloys not in accordance with the invention were prepared having the compositions shown below.
- The resistance of these steels to oxidation was compared by the following scaling test procedure.
- Specimens some k" (13 mm) in diameter by 14" (30 mm) long were machined from bar and ground to a 120 grit finish. They were washed and cleaned in alcohol prior to test.
- The test was of relatively short duration but involved cycling between ambient and test temperature. The test chamber was an alumina tube 2" (50 mm) internal diameter in which the sample was positioned across an open ended alumina boat. Heating was by means of the concentric electric furnace, the temperature being measured by reference to a noble metal thermo-couple, the hot junction of which was immediately above the specimen. The test atmosphere was produced by burning natural gas using excess air over that required for combustion, the flow rates being 1.4 cubic foot and 1.14 cubic foot (0.04 and 0.4 cubic metres) per hour respectively for gas and air. The combustion product, a mixture of nitrogen, oxygenrcarbon dioxide and steam was pre-heated to test temperature before passing through the test chamber; test temperature was established prior to inserting the sample so that heating was rapid. Each test cycle was for six hours, after which the specimens were removed from the test chamber and cooled in a closed container so that any oxide scale which became detached was collected. When cold, the specimen was weighed, together with any detached scale and then scrubbed with a stiff bristle brush to remove any loosely adhering oxide prior to re-weighing to get the starting weight for the next cycle. The whole procedure was repeated for a total of seven cycles and the total gain in weight, that is the sum of the individual gains, expressed as milligrams per square centimetre, for the 42 hour period, using the original surface area for the untested specimen, was taken as the scaling index.
-
- Samples A to C are in accordance with the invention but do not exemplify its most preferred embodiments. It can be seen that the scaling index of A at 1200°C is considerably improved over that of comparative Sample 1 and is still superior to that of comparative Sample 2 despite this latter containing much higher amounts of chromium and aluminium. The scaling index of Samples A to C is quite high however at 1250°C. Examples D to K which contain above 4.5% Al and 15.0% Cr show the still more superior characteristics of steels in accordance with the preferred practice of the invention and it can be seen that low scaling indexes are found even at 12500C.
- It can also be seen that the addition of titanium appears to confer a much smaller but still significant benefit in increased oxidation resistance to the steel containing hafnium. More significantly, the addition of titanium has a substantial effect in reducung the as-cast grain size of the steel and hence greatly improves its hot- working properties. In particular, it was observed that the cast structure of titanium-containing alloys such as B differed from that of alloys A and 2. It was noted that the addition of titanium appeared to have a marked effect on the crystallisation pattern, modifying the coarse columnar crystals of the normal product and giving a more uniform crystal distribution across the section.
- Ingots of the steels were hot worked and it was noted that alloys containing titanium possessed added ductility and less proneness to surface rupture. Resistance to cracking under thermal stress was enhanced.
- Suitable fields of application for steels according to the invention are those in which resistance to oxidation at high temperatures is required. Examples of such uses are in the provision of electric furnace winding material or resistance heating wire generally and in the provision of knitted wire catalyst supports e.g. for use in vehicle exhaust systems for reducing emissions. Another field in which such properties are of value is in the construction of furnaces, for instance fluid bed combustion furnaces.
Claims (7)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8006739A GB2082631A (en) | 1980-02-28 | 1980-02-28 | Ferritic iron-aluminium-chromium alloys |
GB8006739 | 1980-02-28 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0035369A1 true EP0035369A1 (en) | 1981-09-09 |
EP0035369B1 EP0035369B1 (en) | 1985-01-30 |
Family
ID=10511743
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19810300793 Expired EP0035369B1 (en) | 1980-02-28 | 1981-02-26 | Ferritic iron-aluminium-chromium alloys |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0035369B1 (en) |
DE (1) | DE3168563D1 (en) |
GB (1) | GB2082631A (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0091526A2 (en) * | 1982-04-12 | 1983-10-19 | Allegheny Ludlum Corporation | Iron-chromium-aluminium alloy and article and method therefor |
FR2565603A1 (en) * | 1984-06-08 | 1985-12-13 | Osaka Prefecture | PROTHETIC ALLOY OF THE FE-CR-AL TYPE FOR MEDICAL TREATMENT AND METHOD FOR PRODUCING THE SAME |
EP0246939A2 (en) * | 1986-04-21 | 1987-11-25 | Kawasaki Steel Corporation | Fe-Cr-Al stainless steel having high oxidation resistance and spalling resistance and Fe-Cr-Al steel foil for catalyst substrate of catalytic converter |
DE3621569A1 (en) * | 1986-06-27 | 1988-01-21 | Vacuumschmelze Gmbh | Chromium-aluminium-iron alloy thin strip mfr. - used as catalyst support material by rapidly cooling on moving surface |
DE3813685A1 (en) * | 1987-04-24 | 1988-11-03 | Nippon Steel Corp | ROLLED, STAINLESS STEEL FILM WITH A HIGH ALUMINUM CONTENT FOR USE AS A SUBSTRATE OF A CATALYST CARRIER |
GB2224288A (en) * | 1988-11-01 | 1990-05-02 | British Steel Plc | Improvements in and relating to hafnium-containing alloy steels |
EP0387670A1 (en) * | 1989-03-16 | 1990-09-19 | Krupp VDM GmbH | Ferritic-steel alloy |
DE4125212A1 (en) * | 1990-07-31 | 1992-03-19 | Matsushita Electric Works Ltd | METHOD FOR PRODUCING A FERRITIC ALLOY WITH A WEAR-RESISTANT ALUMINUM OXIDE SURFACE LAYER |
EP0497992A1 (en) * | 1989-05-16 | 1992-08-12 | Nippon Steel Corporation | Stainless steel foil for automobile exhaust gaspurifying catalyst carrier and process for preparation thereof |
EP0564665A2 (en) * | 1990-05-14 | 1993-10-13 | Kanthal AB | Cracking Furnace |
EP0625585A1 (en) * | 1993-05-20 | 1994-11-23 | Kawasaki Steel Corporation | Fe-Cr-Al alloy foil having high oxidation resistance for a substrate of a catalytic converter and method of manufacturing same |
WO2020054384A1 (en) * | 2018-09-13 | 2020-03-19 | Jfeスチール株式会社 | Ferritic stainless steel sheet, method for producing same and al plated stainless steel sheet |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3748026A4 (en) * | 2018-01-30 | 2021-01-20 | JFE Steel Corporation | Fe-cr alloy, method for producing same, and resistance heating element |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1558670A1 (en) * | 1964-04-06 | 1970-04-23 | Atomic Energy Commission | Corrosion and rust-resistant alloy |
DE1558657B2 (en) * | 1967-05-31 | 1970-06-04 | Suedwestfalen Ag Stahlwerke | Use of stainless chromium steels as a starting material for finished products with a high surface quality |
US3591365A (en) * | 1969-01-16 | 1971-07-06 | Santoku Metal Ind | Heat resisting corrosion resisting iron chromium alloy |
FR2165453A5 (en) * | 1971-12-14 | 1973-08-03 | Deutsche Edelstahlwerke Ag | |
GB1542694A (en) * | 1975-06-23 | 1979-03-21 | United Technologies Corp | Alumina forming coatings containing hafnium for high temperature applications |
GB1554293A (en) * | 1975-09-22 | 1979-10-17 | Yazaki Corp | Solar collector |
-
1980
- 1980-02-28 GB GB8006739A patent/GB2082631A/en not_active Withdrawn
-
1981
- 1981-02-26 EP EP19810300793 patent/EP0035369B1/en not_active Expired
- 1981-02-26 DE DE8181300793T patent/DE3168563D1/en not_active Expired
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1558670A1 (en) * | 1964-04-06 | 1970-04-23 | Atomic Energy Commission | Corrosion and rust-resistant alloy |
DE1558657B2 (en) * | 1967-05-31 | 1970-06-04 | Suedwestfalen Ag Stahlwerke | Use of stainless chromium steels as a starting material for finished products with a high surface quality |
US3591365A (en) * | 1969-01-16 | 1971-07-06 | Santoku Metal Ind | Heat resisting corrosion resisting iron chromium alloy |
FR2165453A5 (en) * | 1971-12-14 | 1973-08-03 | Deutsche Edelstahlwerke Ag | |
GB1542694A (en) * | 1975-06-23 | 1979-03-21 | United Technologies Corp | Alumina forming coatings containing hafnium for high temperature applications |
GB1554293A (en) * | 1975-09-22 | 1979-10-17 | Yazaki Corp | Solar collector |
Cited By (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0091526B1 (en) * | 1982-04-12 | 1987-08-12 | Allegheny Ludlum Corporation | Iron-chromium-aluminium alloy and article and method therefor |
EP0091526A2 (en) * | 1982-04-12 | 1983-10-19 | Allegheny Ludlum Corporation | Iron-chromium-aluminium alloy and article and method therefor |
FR2565603A1 (en) * | 1984-06-08 | 1985-12-13 | Osaka Prefecture | PROTHETIC ALLOY OF THE FE-CR-AL TYPE FOR MEDICAL TREATMENT AND METHOD FOR PRODUCING THE SAME |
EP0246939A2 (en) * | 1986-04-21 | 1987-11-25 | Kawasaki Steel Corporation | Fe-Cr-Al stainless steel having high oxidation resistance and spalling resistance and Fe-Cr-Al steel foil for catalyst substrate of catalytic converter |
EP0246939A3 (en) * | 1986-04-21 | 1988-10-12 | Kawasaki Steel Corporation | Fe-cr-al stainless steel having high oxidation resistance and spalling resistance and fe-cr-al steel foil for catalyst substrate of catalytic converter |
US4904540A (en) * | 1986-04-21 | 1990-02-27 | Kawasaki Steel Corp. | Fe-Cr-Al stainless steel having high oxidation resistance and spalling resistance and Fe-Cr-Al steel for catalyst substrate of catalytic converter |
DE3621569A1 (en) * | 1986-06-27 | 1988-01-21 | Vacuumschmelze Gmbh | Chromium-aluminium-iron alloy thin strip mfr. - used as catalyst support material by rapidly cooling on moving surface |
DE3813685A1 (en) * | 1987-04-24 | 1988-11-03 | Nippon Steel Corp | ROLLED, STAINLESS STEEL FILM WITH A HIGH ALUMINUM CONTENT FOR USE AS A SUBSTRATE OF A CATALYST CARRIER |
GB2224288B (en) * | 1988-11-01 | 1992-05-13 | British Steel Plc | Improvements in and relating to hafnium-containing alloy steels |
GB2224288A (en) * | 1988-11-01 | 1990-05-02 | British Steel Plc | Improvements in and relating to hafnium-containing alloy steels |
EP0370645A1 (en) * | 1988-11-01 | 1990-05-30 | Avesta Sheffield Limited | Improvements in and relating to hafnium-containing alloy steels |
EP0387670A1 (en) * | 1989-03-16 | 1990-09-19 | Krupp VDM GmbH | Ferritic-steel alloy |
EP0497992A1 (en) * | 1989-05-16 | 1992-08-12 | Nippon Steel Corporation | Stainless steel foil for automobile exhaust gaspurifying catalyst carrier and process for preparation thereof |
EP0658633A2 (en) * | 1989-05-16 | 1995-06-21 | Nippon Steel Corporation | Stainless steel foil for automobile exhaust gaspurifying catalyst carrier and process for preparation thereof |
EP0658633A3 (en) * | 1989-05-16 | 1995-10-25 | Nippon Steel Corp | Stainless steel foil for automobile exhaust gaspurifying catalyst carrier and process for preparation thereof. |
EP0564665A2 (en) * | 1990-05-14 | 1993-10-13 | Kanthal AB | Cracking Furnace |
EP0564665A3 (en) * | 1990-05-14 | 1993-12-01 | Kanthal Ab | Cracking furnace |
DE4125212A1 (en) * | 1990-07-31 | 1992-03-19 | Matsushita Electric Works Ltd | METHOD FOR PRODUCING A FERRITIC ALLOY WITH A WEAR-RESISTANT ALUMINUM OXIDE SURFACE LAYER |
EP0625585A1 (en) * | 1993-05-20 | 1994-11-23 | Kawasaki Steel Corporation | Fe-Cr-Al alloy foil having high oxidation resistance for a substrate of a catalytic converter and method of manufacturing same |
WO2020054384A1 (en) * | 2018-09-13 | 2020-03-19 | Jfeスチール株式会社 | Ferritic stainless steel sheet, method for producing same and al plated stainless steel sheet |
JP2020059927A (en) * | 2018-09-13 | 2020-04-16 | Jfeスチール株式会社 | Ferritic stainless steel sheet |
JP6687177B1 (en) * | 2018-09-13 | 2020-04-22 | Jfeスチール株式会社 | Method for producing Al-based plated stainless steel sheet and ferritic stainless steel sheet |
US11767573B2 (en) | 2018-09-13 | 2023-09-26 | Jfe Steel Corporation | Ferritic stainless steel sheet and method of producing same, and al or al alloy coated stainless steel sheet |
Also Published As
Publication number | Publication date |
---|---|
DE3168563D1 (en) | 1985-03-14 |
GB2082631A (en) | 1982-03-10 |
EP0035369B1 (en) | 1985-01-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0035369B1 (en) | Ferritic iron-aluminium-chromium alloys | |
US4789412A (en) | Cobalt-base alloy having high strength and high toughness, production process of the same, and gas turbine nozzle | |
GB2070642A (en) | Ferritic iron-aluminium- chromium alloys | |
Kawahara | Effect of additive elements on cold workability in FeCo alloys | |
CA1066922A (en) | Heat-resistant allow for welded structures | |
CH375903A (en) | Niobium alloy | |
EP0549286A1 (en) | High temperature resistant Ni-Cr alloy | |
JP3397092B2 (en) | Al-containing austenitic stainless steel with excellent hot workability | |
EP0269973A2 (en) | Carburization resistant alloy | |
WO2003029505A1 (en) | Ferritic stainless steel for use in high temperature applications and method for producing a foil of the steel | |
CA2088065C (en) | Controlled thermal expansion alloy and article made therefrom | |
US5045404A (en) | Heat-resistant stainless steel foil for catalyst-carrier of combustion exhaust gas purifiers | |
JPH0321622B2 (en) | ||
EP0374507A1 (en) | Niobium base high temperature alloy | |
US4456481A (en) | Hot workability of age hardenable nickel base alloys | |
JPH06184700A (en) | Alloy with high strength, non-magnetism, and low thermal expansion | |
US3816111A (en) | Chromium-base alloy for making a chill-mold and a process of making same | |
GB2083499A (en) | Austenitic steel | |
JPH0621303B2 (en) | Method for producing low oxygen Ti alloy | |
JPH03134144A (en) | Nickel-base alloy member and its manufacture | |
JPH04502938A (en) | Iron, nickel, chromium base alloy | |
US3202506A (en) | High-temperature oxidation-resistant cobalt base alloys | |
JPS58150119A (en) | Alloy having high magnetic permeability for magnetic recording and reproducing head and its production, and magnetic recording and reproducing head | |
JPH08311620A (en) | Stainless steel excellent in hot workability and molten salt corrosion resistance | |
JP2776593B2 (en) | Grain refinement method for titanium-aluminum intermetallic compound |
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 GB SE |
|
17P | Request for examination filed |
Effective date: 19820109 |
|
RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: SHEFFIELD FORGEMASTERS LIMITED |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Designated state(s): DE FR GB SE |
|
REF | Corresponds to: |
Ref document number: 3168563 Country of ref document: DE Date of ref document: 19850314 |
|
ET | Fr: translation filed | ||
PLBI | Opposition filed |
Free format text: ORIGINAL CODE: 0009260 |
|
26 | Opposition filed |
Opponent name: THYSSEN EDELSTAHLWERKE AG Effective date: 19851023 |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: 732 |
|
PLBM | Termination of opposition procedure: date of legal effect published |
Free format text: ORIGINAL CODE: 0009276 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: OPPOSITION PROCEDURE CLOSED |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: TP |
|
27C | Opposition proceedings terminated |
Effective date: 19860801 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Effective date: 19880227 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Effective date: 19881101 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee | ||
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: 19881118 |
|
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: 19891027 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |
|
EUG | Se: european patent has lapsed |
Ref document number: 81300793.7 Effective date: 19880927 |