US4290805A
Expired / Lapsed
US
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Method for obtaining iron-based alloys allowing in particular their mechanical properties to be improved by the use of lanthanum, and iron-based alloys obtained by the said method
Assignee: Universelle D'acetylene et D'electro-Metallurgie Cie
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Filing: 1979-04-03
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Granted: 1981-09-22
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Expires: 1999-04-03
Abstract
Abstract This invention relates to the use of lanthanum in the production of iron-based alloys. Accordingly, is provided a method comprising adding at least 0.0001 to about 0.5 to 2 weight percent of lanthanum to said iron-based alloy during its production. Thus the solidification curve is modified, as shown in FIG. 2, thereby reducing or preventing certain defects of said alloys, such as pinholes and cavities in spheroidal graphite cast-irons, carbides in flaky graphite grey-iron; the castability, rollability and anisotropy of steels are improved.
Inventors
- 👤 Mario Gorgerino
- 👤 Daniel Videau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:49
CPC Classifications
C; C22; C22C; C22C37/00; C21; C21C; C21C1/00; C22C35/00; C22C37/04; C22C38/00; C22C38/002
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
52 words
A method for obtaining iron-based alloys substantially devoid of pinholes and cavities in spheroidal graphite cast-irons, and of carbides in flaky graphite grey-iron, while providing improved castibility, rollability, anisotropy and mechanical properties thereof, which comprises adding 0.0001 to about 2 weight percent of lanthanum to the said iron-based alloy during its production.
Claim 2
Independent Claim
52 words
A method for obtaining iron-based alloys substantially devoid of pinholes and cavities in spheroidal graphite cast-irons, and of carbides in flaky graphite grey-iron, while providing improved castibility, rollability, anisotropy and mechanical properties thereof, which comprises adding 0.0001 to about 2 weight percent of lanthanum to the said iron-based alloy during its production.
Claim 3
Dependent Claim
16 words
The method of claim 1, wherein 0.0001 to about 0.01 weight percent of lanthanum is added.
Claim 4
Dependent Claim
17 words
The method of claim 1, wherein about 0.001 to about 0.01 weight percent of lanthanum is added.
Claim 5
Dependent Claim
40 words
The method of claim 1, wherein spheroidal graphite cast-iron is prepared from a basic cast-iron having the following composition (weight percent): C=3.3 to 3.8 Si=1.8 to 3 Mn=0.1 to 0.5 P=≦0.05 S=≦0.020 Fe=the balance to which the lanthanum is added.
Claim 6
Dependent Claim
44 words
The method of claim 1, wherein the lanthanum is added in the form of alloys with a metal capable of forming with lanthanum a homogeneous compound, in a proportion of 0.01 to 90 weight percent of lanthanum, said alloy having a low cerium content.
Claim 7
Dependent Claim
25 words
The method of claim 1, wherein said lanthanum is added in the form of a compound obtained from lathanides and having a low cerium content.
Claim 8
Dependent Claim
21 words
The method of claim 5, wherein the lantahnum/rare earths weight ratio in the lanthanides compounds is at least higher than 2/1.
Claim 9
Dependent Claim
22 words
The method of claim 1, wherein the lanthanum is added in the form of metal lanthanum having a purity greater than 99%.
Claim 10
Dependent Claim
31 words
The method of claim 5, wherein the lanthanum is added in the form of an alloy based on Si-La-Al, La-Ni, La-Fe-Si, La-Fe-Mn, Si-Ca-Mg-La, La-Cr or Si-La-Mn, with iron constituting the balance.
Claim 11
Dependent Claim
28 words
The method of claim 9, wherein the lanthanum is added in the form of an alloy having the following composition (weight percent): Si=60-90 Ca=0.01-4 Al=0.1-4 La=0.01-5 Fe=the balance.
Claim 12
Dependent Claim
28 words
The method of claim 9, wherein the lanthanum is added in the form of an alloy having the following composition (weight percent): Si=45-70 Ca=0.01-4 Mg=3-30 La=0.01-5 Fe=the balance.
Claim 13
Dependent Claim
15 words
Method of claim 6, wherein said lanthanum compound is a lanthanide chloride, fluoride or oxide.
Claim 14
Dependent Claim
24 words
Method according to claim 7, wherein the ratio of lanthanum to rare earth other than lanthanum in said lanthanides compound is greater than 10/1.
Claim 15
Dependent Claim
20 words
Method according to claim 7 wherein the ratio of lanthanum to rare earths other than lanthanum is greater than 100/1.
Claim 16
Dependent Claim
20 words
Method according to claim 1 wherein the ratio of lanthanum to rare earth other than lanthanum is greater than 10/1.
Claim 17
Dependent Claim
20 words
Method according to claim 1 wherein the ratio of lanthanum to rare earth other than lanthanum is greater than 100/1.
Claim 18
Dependent Claim
22 words
The method of claim 6, wherein the lanthanum rare earths weight ratio in the lanthanides compounds is at least higher than 2/1.
References Cited (Backward Citations)
US3065070A
Cited
US3492118A
Cited
US3729309A
Cited
US3666570A
Cited
US3765875A
Cited
US3928083A
Cited
US3816103A
Cited
US3871870A
Cited
US3997338A
Cited
US4086086A
Cited
US4042381A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-21 | 1985-03-23 | 1985-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-21 | 1989-03-23 | 1989-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-21 | 1993-03-23 | 1993-09-22 | $7700.00 | Window Closed / Lapsed |