US4539042A
Expired / Lapsed
US
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Preventing an increase of the nitrogen content in molten steel
Assignee: FOLEY ASC Inc A MN CORP
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Filing: 1984-02-22
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Granted: 1985-09-03
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Expires: 2004-02-22
Abstract
Abstract Following the discharge of steel from a steel producing converter, the adding and inclusion of nitrogen is impeded by surrounding the stream of pouring steel with a layer of limestone at a grain size not exceeding 5 mm. Practice has shown that the nitrogen content can well remain below a content of 0.005%.
Inventors
- 👤 Hans Gruner
- 👤 Arnold Pfeiffer
- 👤 Heinrich-Wilhelm Rommerswinkel
- 👤 Rolf Vest
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:20
CPC Classifications
C; C21; C21C; C21C7/00; C21C7/0037; C21C7/0043
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
57 words
Method fo preventing the inclusion of nitrogen in molten steel which is treated following a poured discharge from a converter, comprising the steps of protectively enveloping a stream of steel as poured from the converter, with a fine grain material yielding carbon dioxide, the enveloping material reaching a vessel into which the steel is poured simultaneously therewith.
Claim 2
Dependent Claim
57 words
Method fo preventing the inclusion of nitrogen in molten steel which is treated following a poured discharge from a converter, comprising the steps of protectively enveloping a stream of steel as poured from the converter, with a fine grain material yielding carbon dioxide, the enveloping material reaching a vessel into which the steel is poured simultaneously therewith.
Claim 3
Dependent Claim
30 words
Method as in claim 1 wherein the supplemental material includes an inert carrier gas other than nitrogen and further includes a carbonate with a grain size not exceeding 5 mm.
Claim 4
Dependent Claim
28 words
Method as in claim 1 wherein the supplemental material is continuously applied to the pouring steel directly underneath a pouring opening, the application to continue throughout the discharge.
Claim 5
Dependent Claim
25 words
Method as in claim 1 wherein the supplemental is added above the surface of the molten steel in the vessel into which it is poured.
Claim 6
Dependent Claim
25 words
Method as in claim 1 wherein the adding of the supplemental material is carried out in coincidence with flushing gas treatment of the molten steel.
Claim 7
Dependent Claim
16 words
Method as in claim 5 comprising the step of adding the material above the flushing spot.
Claim 8
Dependent Claim
19 words
Method as in claim 1 wherein the material added is limestone at a grain size not exceeding 5 mm.
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) | 1988-09-02 | 1989-03-04 | 1989-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-02 | 1993-03-04 | 1993-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-02 | 1997-03-04 | 1997-09-03 | $7700.00 | Window Closed / Lapsed |