Patent US4079224A successfully refreshed from Google Patents.
US4079224A
Expired / Lapsed
US
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Method for preventing brittle fracture of steel pipe structures
Assignee: Nippon Steel Corp
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Filing: 1975-10-29
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Granted: 1978-03-14
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Expires: 1995-10-29
Abstract
Abstract A method of preventing brittle fracture of a pipe structure constructed by welding welded or continuous welded steel pipes, which comprise subjecting a certain length of the seamed portion adjacent to the butt welded portion of the steel pipe to an arc treatment.
Inventors
- 👤 Hiroyo Haga
- 👤 Tovoaki Bada
- 👤 Sigeo Fujimori
- 👤 Tuguro Kikuno
- 👤 Hiroshi Nozaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:58
CPC Classifications
C; C21; C21D; C21D9/00; C21D9/50
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
59 words
A method of preventing brittle fracture of a pipe structure constructed by butt welding a continuous welded steel pipe to a second member, which comprises subjecting a certain length of the portion of the continuous weld adjacent said butt weld to an arc treatment which comprises arc remelting or laying a bead of weld material over the continuous weld.
Claim 2
Independent Claim
59 words
A method of preventing brittle fracture of a pipe structure constructed by butt welding a continuous welded steel pipe to a second member, which comprises subjecting a certain length of the portion of the continuous weld adjacent said butt weld to an arc treatment which comprises arc remelting or laying a bead of weld material over the continuous weld.
Claim 3
Dependent Claim
27 words
A method according to claim 1, in which the arc treatment is done along a length ranging from 100 to 150 mm from the steel pipe end.
Claim 4
Dependent Claim
21 words
A method as in claim 2, wherein the arc treatment comprises laying a bead of weld material over the continuous weld.
Claim 5
Dependent Claim
20 words
A method according to claim 1, in which the arc treatment is done before butt welding of the steel pipes.
Claim 6
Dependent Claim
21 words
A method as in claim 4, wherein the arc treatment comprises laying a bead of weld material over the continuous weld.
Claim 7
Dependent Claim
20 words
A method according to claim 1, in which the arc treatment is done after butt welding of the steel pipes.
Claim 8
Dependent Claim
21 words
A method as in claim 6, wherein the arc treatment comprises laying a bead of weld material over the continuous weld.
Claim 9
Dependent Claim
21 words
A method as in claim 1, wherein the arc treatment comprises laying a bead of weld material over the continuous weld.
Claim 10
Independent Claim
81 words
A method of joining a tube having a welded seam and an end to another member, comprising the steps of butt welding the end of the tube to the other member and arc treating a portion of the tube along the seam adjacent the end at a time different from the butt welding step; said arc treating step including applying, along the seam, an arc producing sufficient heat to remelt the tube at the seam and allowing the seam to cool.
Claim 11
Independent Claim
81 words
A method of joining a tube having a welded seam and an end to another member, comprising the steps of butt welding the end of the tube to the other member and arc treating a portion of the tube along the seam adjacent the end at a time different from the butt welding step; said arc treating step including applying, along the seam, an arc producing sufficient heat to remelt the tube at the seam and allowing the seam to cool.
Claim 12
Dependent Claim
28 words
A method as in claim 9, wherein the arc treating step includes depositing a layer of metal on the portion of the seam by means of the arc.
Claim 13
Dependent Claim
27 words
A method as in claim 10, in which the arc treatment is done along a length ranging from 100 to 150 mm from the steel pipe end.
Claim 14
Dependent Claim
20 words
A method as in claim 10, in which the arc treatment is done before butt welding of the steel pipes.
Claim 15
Dependent Claim
20 words
A method as in claim 10, in which the arc treatment is done after butt welding of the steel pipes.
Claim 16
Independent Claim
70 words
A method of protecting a pipe, having a welded seam and an end butt welded to another structure, comprising the step of arc treating the pipe at a portion of the seam adjacent the end at a time different from the butt welding, and allowing the pipe to cool, said arc treating step including applying along the seam, an arc producing sufficient heat to remelt the tube at the seam.
Claim 17
Independent Claim
70 words
A method of protecting a pipe, having a welded seam and an end butt welded to another structure, comprising the step of arc treating the pipe at a portion of the seam adjacent the end at a time different from the butt welding, and allowing the pipe to cool, said arc treating step including applying along the seam, an arc producing sufficient heat to remelt the tube at the seam.
Claim 18
Dependent Claim
71 words
A method as in claim 14, comprising the steps of butt welding the end of the tube to the other member and arc treating a portion of the tube along the seam adjacent the end at a time different from the butt welding step; said arc treating step including applying, along the seam, an arc producing sufficient heat to remelt the tube at the seam and allowing the seam to cool.
Claim 19
Dependent Claim
27 words
A method as in claim 15, in which the arc treatment is done along a length ranging from 100 to 150 mm from the steel pipe end.
Claim 20
Dependent Claim
20 words
A method as in claim 15, in which the arc treatment is done before butt welding of the steel pipes.
Claim 21
Dependent Claim
20 words
A method as in claim 15, in which the arc treatment is done after butt welding of the steel pipes.
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) | 1981-03-13 | 1981-09-12 | 1982-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-13 | 1985-09-12 | 1986-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-13 | 1989-09-12 | 1990-03-14 | $7700.00 | Window Closed / Lapsed |