US3956010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dry pickling method
Assignee: United States Steel Corp
•
Filing: 1974-10-01
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Granted: 1976-05-11
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Expires: 1994-10-01
Abstract
Abstract Hot rolled steel is pickled with chlorine gas at temperatures between about 1250°to 2500°F.
Inventors
- 👤 Robert H. Kachik
- 👤 Arthur J. Pignocco
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:13
CPC Classifications
C; C23; C23G; C23G5/00; B; B21; B21B; B21B45/00; B21B45/04; B21B45/06
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
64 words
Method of pickling hot steel having an external layer of metal oxide scale comprising contacting the hot steel with chlorine gas in the substantial absence of a reducing agent, said chlorine gas being impinged against the steel surface at a rate of at least 12cc. per square inch of steel surface, to loosen scale thereon and then removing the loosened scale by mechanical action.
Claim 2
Dependent Claim
64 words
Method of pickling hot steel having an external layer of metal oxide scale comprising contacting the hot steel with chlorine gas in the substantial absence of a reducing agent, said chlorine gas being impinged against the steel surface at a rate of at least 12cc. per square inch of steel surface, to loosen scale thereon and then removing the loosened scale by mechanical action.
Claim 3
Dependent Claim
17 words
Method of claim 1 in which the scale is at least one ten-thousandth of an inch thick.
Claim 4
Dependent Claim
17 words
Method of claim 1 in which the scale is removed by the force of a water jet.
Claim 5
Dependent Claim
14 words
Method of claim 1 in which the chlorine is diluted with an inert gas.
Claim 6
Dependent Claim
18 words
Method of claim 1 in which the hot strip steel is at a temperature of at least 1250°F.
Claim 7
Dependent Claim
18 words
Method of claim 1 in which the steel is cooled prior to removing the scale by mechanical action.
Claim 8
Dependent Claim
18 words
Method of claim 1 in which the hot strip steel is at a temperature of 1400°F to 1700°F.
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) | 1979-05-11 | 1979-11-10 | 1980-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-11 | 1983-11-10 | 1984-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-11 | 1987-11-10 | 1988-05-11 | $7700.00 | Window Closed / Lapsed |