US4042381A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control of inclusion morphology in steel
Assignee: Ltv Steel Co Inc
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Filing: 1976-07-06
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Granted: 1977-08-16
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Expires: 1996-07-06
Abstract
Abstract Effective, low cost sulfide shape control is obtained using in combination titanium and a rare earth metal, e.g., mischmetal, in steels meeting the following specifications: at least 0.020% aluminum, no more than 0.010% nitrogen, no more than 0.025% sulfur, no more than 0.70% manganese, at least 0.020% titanium, and at least 0.020% of at least one rare earth metal. The steels are characterized by sulfide inclusions having a globular and/or fine, short blocky shape.
Inventors
- 👤 Jerry D. Thomas
- 👤 William F. Hladio
- 👤 Leo V. Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:15
CPC Classifications
C; C21; C21C; C21C7/00; C22; C22C; C22C33/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
60 words
A method of producing steel characterized by shaped sulfide inclusions comprising the steps of preparing a steel melt containing in amounts by weight: at least 0.020% aluminum no more than 0.010% nitrogen no more than 0.025% sulfur no more than 0.70% manganese and incorporating in said melt from 0.020-0.080% titanium and from 0.020-0.060% of at least one rare earth metal.
Claim 2
Independent Claim
60 words
A method of producing steel characterized by shaped sulfide inclusions comprising the steps of preparing a steel melt containing in amounts by weight: at least 0.020% aluminum no more than 0.010% nitrogen no more than 0.025% sulfur no more than 0.70% manganese and incorporating in said melt from 0.020-0.080% titanium and from 0.020-0.060% of at least one rare earth metal.
Claim 3
Dependent Claim
36 words
The method as claimed in claim 1 wherein the titanium is incorporated in said melt no earlier than the aluminum, and wherein the rare earth metal is incorporated in said melt no earlier than the titanium.
Claim 4
Dependent Claim
32 words
The method as claimed in claim 1 wherein the titanium is present in a maximum amount of 0.060%, and wherein the rare earth metal is present in a maximum amount of 0.040%.
Claim 5
Dependent Claim
14 words
The method as claimed in claim 1 wherein the rare earth metal is mischmetal.
Claim 6
Independent Claim
94 words
A method of producing steel characterized by shaped sulfides comprising the steps of preparing in a furnace a steel melt containing in amounts by weight: no more than 0.010% nitrogen no more than 0.025% sulfur no more than 0.70% manganese; transferring the melt to a ladle and incorporating in the melt at least 0.020% aluminum and from 0.020-0.060% titanium, the titanium being added to the melt after the aluminum; maintaining the melt with the foregoing composition; pouring the melt into a mold; and incorporating in the melt a mold addition of from 0.020-0.040% mischmetal.
Claim 7
Independent Claim
94 words
A method of producing steel characterized by shaped sulfides comprising the steps of preparing in a furnace a steel melt containing in amounts by weight: no more than 0.010% nitrogen no more than 0.025% sulfur no more than 0.70% manganese; transferring the melt to a ladle and incorporating in the melt at least 0.020% aluminum and from 0.020-0.060% titanium, the titanium being added to the melt after the aluminum; maintaining the melt with the foregoing composition; pouring the melt into a mold; and incorporating in the melt a mold addition of from 0.020-0.040% mischmetal.
Claim 8
Independent Claim
92 words
A method of producing steel characterized by shaped sulfides comprising the steps of preparing in a furnace a steel melt containing in amounts by weight: no more than 0.010% nitrogen no more than 0.025% sulfur no more than 0.70% manganese; transferring the melt to a ladle and incorporating in the melt at least 0.020% aluminum and maintaining the melt in the foregoing composition; pouring the melt into a mold; and incorporating in the melt a mold addition of from 0.020-0.060% titanium followed or accompanied by a mold addition of from 0.020-0.040% mischmetal.
Claim 9
Independent Claim
92 words
A method of producing steel characterized by shaped sulfides comprising the steps of preparing in a furnace a steel melt containing in amounts by weight: no more than 0.010% nitrogen no more than 0.025% sulfur no more than 0.70% manganese; transferring the melt to a ladle and incorporating in the melt at least 0.020% aluminum and maintaining the melt in the foregoing composition; pouring the melt into a mold; and incorporating in the melt a mold addition of from 0.020-0.060% titanium followed or accompanied by a mold addition of from 0.020-0.040% mischmetal.
Claim 10
Dependent Claim
46 words
A steel characterized by the presence of sulfides having globular and short blocky shapes, said steel containing in amounts by weight: aluminum 0.020% minimum, nitrogen 0.010% maximum, sulfur 0.025% maximum, manganese 0.70% maximum, from 0.020-0.080% titanium, and from 0.020-0.060% of at least one rare earth metal.
Claim 11
Dependent Claim
46 words
A steel characterized by the presence of sulfides having globular and short blocky shapes, said steel containing in amounts by weight: aluminum 0.020% minimum, nitrogen 0.010% maximum, sulfur 0.025% maximum, manganese 0.70% maximum, from 0.020-0.080% titanium, and from 0.020-0.060% of at least one rare earth metal.
Claim 12
Dependent Claim
18 words
A steel as claimed in claim 7 wherein the titanium is present in a maximum amount of 0.060%.
Claim 13
Dependent Claim
20 words
A steel as claimed in claim 7 wherein the rare earth metal is present in a maximum amount of 0.040%.
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) | 1980-08-15 | 1981-02-14 | 1981-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-15 | 1985-02-14 | 1985-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-15 | 1989-02-14 | 1989-08-16 | $7700.00 | Window Closed / Lapsed |