US3784374A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of improving the machinability and mechanical properties of a steel
Assignee: FRANCAISE DES ACIERS SPECIAUX Cie
•
Filing: 1971-05-07
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Granted: 1974-01-08
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Expires: 1991-05-07
Abstract
Abstract The machinability and mechanical properties of a steel are simultaneously improved by adding to the molten steel a sodium oxysulphide and one or more of selenium, tellurium and bismuth. The oxysulphide is suitably introduced into the ladle and the selenium, tellurium and bismuth into the molten steel when it is in the ingot mould.
Inventors
- 👤 E Almand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:55
CPC Classifications
C; C21; C21C; C21C7/00; C21C7/04; C21C7/076; C22; C22C; C22C38/00; C22C38/60; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
20 words
A method according to claim 1 wherein the sodium oxysulphide is selected from sodium sulphite, sodium hyposulphite and sodium metabisulphite.
Claim 2
Independent Claim
62 words
A method of making steel which consists essentially of adding to the steel, while it is molten and in the ladle, a sodium oxysulphide and adding to the molten steel in the ingot mold from 0.015 to 0.025 percent in total of at least one element selected from the group consisting of selenium, tellurium and bismuth, tellerium being not greater than 0.020%.
Claim 3
Dependent Claim
17 words
A method according to claim 3 wherein the selenium is added to the steel as sodium oxyselenide.
Claim 4
Dependent Claim
20 words
A method according to claim 3 wherein the sodium oxysulphide is selected from sodium sulphite, sodium hyposulphite and sodium metabisulphite.
Claim 5
Independent Claim
53 words
A method of improving the machinability and mechanical properties of a steel which consists essentially of incorporating in the steel, whilst it is molten, sodium sulphite in the ladle and selenium in the ingot mold, and allowing the steel to cool whereby globules of sulphides are finely and homogeneously distributed throughout the steel.
References Cited (Backward Citations)
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US2272277A
Cited
US3152889A
Cited
US3169857A
Cited
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US3152890A
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US3574606A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |