Patent US4995907A successfully refreshed from Google Patents.
US4995907A
Expired / Lapsed
US
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Method of deoxiding and alloying steel
Assignee: Primetals Technologies Austria GmbH
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Filing: 1990-03-22
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Granted: 1991-02-26
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Expires: 2010-03-22
Abstract
Abstract To produce deoxidized steel by the addition of deoxidizing agents to molten crude steel having an oxygen content of at least 200 ppm and the subsequent addition of alloying agents, the deoxidation is realized at least partially under the formation of liquid deoxidation products by the simultaneous addition of the two deoxidizing agents FeSi and FeMn. The method according to the invention ensures a great analytical precision of the steel and is not limited to the production of certain steels.
Inventors
- 👤 Wilfried Pirklbauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:51
CPC Classifications
C; C21; C21C; C21C7/00; C21C7/04; C21C7/06
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
62 words
In a method of deoxidizing and alloying steel by preparing molten crude steel having an oxygen content of at least 200 ppm, p1 adding deoxidizing agents to said molten crude steel, and subsequently adding alloying agents, the improvement wherein FeSi and FeMn are simultaneously added as said deoxidizing agents at a ratio that at least partially yields liquid deoxidation products during deoxidizing.
Claim 2
Dependent Claim
62 words
In a method of deoxidizing and alloying steel by preparing molten crude steel having an oxygen content of at least 200 ppm, p1 adding deoxidizing agents to said molten crude steel, and subsequently adding alloying agents, the improvement wherein FeSi and FeMn are simultaneously added as said deoxidizing agents at a ratio that at least partially yields liquid deoxidation products during deoxidizing.
Claim 3
Dependent Claim
22 words
A method as set forth in claim 1, further comprising adding at least one of C and Al as additional deoxidizing agents.
Claim 4
Dependent Claim
14 words
A method as set forth in claim 2, wherein C is added before Al.
Claim 5
Dependent Claim
25 words
The method of claim 1, wherein the ratio based upon weight of FeSi to FeMn is between 1:1.923 to 1:2.236 per ton of crude steel.
Claim 6
Dependent Claim
20 words
The method of claim 1, wherein the liquid deoxidation products comprise SiO=Hd 2, MnO and Al 2 O 3 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-02-25 | 1994-08-27 | 1995-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-25 | 1998-08-27 | 1999-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-25 | 2002-08-27 | 2003-02-26 | $7700.00 | Window Closed / Lapsed |