Patent US3698070A successfully refreshed from Google Patents.
US3698070A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of fabricating seamless steel pipes
Assignee: Cefilac SA
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Filing: 1970-09-24
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Granted: 1972-10-17
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Expires: 1990-09-24
Abstract
Abstract A process for the manufacture of seamless steel tubing comprising continuous casting rectangular cross-section bars, cutting the bars into billets, heating the billets, upsetting and piercing the billets into hollow circular cross-sectioned blanks, hot extruding the blanks into seamless tubes and stretch reducing the seamless tubes where necessary.
Inventors
- 👤 Jacques Sejournet
- 👤 Jose Ignacio Martinez Garin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:53
CPC Classifications
B; B21; B21C; B21C23/00; B21C23/02; B21C23/04; B21C23/08; B21C23/085; Y; Y10; Y10S; Y10S29/00; Y10S29/047; Y10T; Y10T29/00; Y10T29/49; Y10T29/4998; Y10T29/49988; Y10T29/49989
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
92 words
A process for manufacturing seamless tubes in all grades of steel from cross-sectionally rectangular bars having a cast structure and not a wrought structure, which bars issue from a continuous casting installation and have not been subjected to any intermediate metalworking steps, said process comprising in sequence: A. cutting the bars into billets of a desired weight; B. heating the billets to deformation temperature; C. transforming the billets into circular cross-sectioned and clear through hollow blanks in an upsetting-piercing press; and D. hot extruding the blanks into seamless tubes of desired dimension.
Claim 2
Dependent Claim
92 words
A process for manufacturing seamless tubes in all grades of steel from cross-sectionally rectangular bars having a cast structure and not a wrought structure, which bars issue from a continuous casting installation and have not been subjected to any intermediate metalworking steps, said process comprising in sequence: A. cutting the bars into billets of a desired weight; B. heating the billets to deformation temperature; C. transforming the billets into circular cross-sectioned and clear through hollow blanks in an upsetting-piercing press; and D. hot extruding the blanks into seamless tubes of desired dimension.
Claim 3
Dependent Claim
24 words
The process of claim 1 wherein the transforming of the billet into the circular cross-sectioned and hollow blanks includes initially upsetting and then piercing.
Claim 4
Dependent Claim
41 words
The process of claim 1 including after hot extruding the steps of stretch reducing the seamless tubes on a stretch reducing mill to reduce the diameter of the tubes and adjust the wall thickness to obtain precision tolerances of the tubes.
Claim 5
Dependent Claim
40 words
The process of claim 1 wherein the cutting step A and the heating step B taken place immediately after the continuous casting operation, so that the majority of the casting heat is retained and the heating step B is minimized.
Claim 6
Dependent Claim
26 words
The process of claim 1 wherein a glass lubricant is employed in at least one of the transforming step C and the hot extruding step D.
Claim 7
Dependent Claim
16 words
The process of claim 1 including the step of heating the hollow blanks before hot extruding.
Claim 8
Dependent Claim
20 words
The process of claim 3 including the step of passing the seamless tube through a heating furnace before stretch reducing.
References Cited (Backward Citations)
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US3038250A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |