US4060407A
Expired / Lapsed
US
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Methods and apparatus for adding mischmetal to molten steel
Assignee: Reactive Metals and Alloys Corp
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Filing: 1976-11-22
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Granted: 1977-11-29
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Expires: 1996-11-22
Abstract
Abstract A method, apparatus and alloy for adding mischmetal to molten steel by filling a metal canister with a mischmetal-magnesium alloy in the range 1% to 2.5% magnesium, plunging the metal canister beneath the surface of the steel bath being treated and holding the canister submerged in the bath until the mischmetal has dissolved.
Inventors
- 👤 Joseph R. Jackman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:31
CPC Classifications
C; C21; C21C; C21C7/00; C21C7/04; C21C7/064
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
101 words
The method of adding mischmetal to steel comprising the steps of: a. forming a composite article consisting essentially of a metal canister filled with a mischmetal-magnesium alloy in which the magnesium is present in an amount sufficient to generate stirring in a molten steel bath to which it is added in the range 1% to 2.5% and the balance is mischmetal, b. plunging the metal canister containing mischmetal magnesium alloy beneath the surface of a molten steel bath being treated, and c. holding the metal canister beneath the surface of the steel bath until the canister and mischmetal-magnesium alloy is dissolved.
Claim 2
Independent Claim
101 words
The method of adding mischmetal to steel comprising the steps of: a. forming a composite article consisting essentially of a metal canister filled with a mischmetal-magnesium alloy in which the magnesium is present in an amount sufficient to generate stirring in a molten steel bath to which it is added in the range 1% to 2.5% and the balance is mischmetal, b. plunging the metal canister containing mischmetal magnesium alloy beneath the surface of a molten steel bath being treated, and c. holding the metal canister beneath the surface of the steel bath until the canister and mischmetal-magnesium alloy is dissolved.
Claim 3
Dependent Claim
29 words
A method as claimed in claim 1 wherein the canister has a central rod having radial fingers imbebbed in the mischmetal-magnesium alloy, fixing the alloy firmly within the canister.
Claim 4
Dependent Claim
29 words
A method as claimed in claim 1 wherein the molten steel bath is contained in a ladle having a ladle glaze adjusted to be high in CaO and MgO.
Claim 5
Dependent Claim
28 words
A method as claimed in claim 1 wherein the molten steel bath is contained in a ladle having a slag adjusted to a V-ratio in excess of 3.0.
Claim 6
Dependent Claim
23 words
A method as claimed in claim 1 wherein the steel bath being treated has a residual aluminum content of not less than 0.040.
Claim 7
Dependent Claim
20 words
A rare earth addition alloy consisting essentially of about 1 to 2.5% magnesium and the balance mischmetal with ordinary impurities.
Claim 8
Dependent Claim
20 words
A rare earth addition alloy consisting essentially of about 1 to 2.5% magnesium and the balance mischmetal with ordinary impurities.
Claim 9
Dependent Claim
18 words
A rare earth addition alloy as claimed in claim 6 wherein the magnesium is about 1.75% to 2%.
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) | 1980-11-28 | 1981-05-30 | 1981-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-28 | 1985-05-30 | 1985-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-28 | 1989-05-30 | 1989-11-29 | $7700.00 | Window Closed / Lapsed |