US4125924A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing composite metal pipe
Assignee: United States Steel Corp
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Filing: 1977-04-04
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Granted: 1978-11-21
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Expires: 1997-04-04
Abstract
Abstract A composite metal pipe or tube is formed by cold sink drawing a first pipe to work-harden the walls thereof, and then telescoping a softer pipe thereover and cold sink drawing the telescoped combination to stretch and compress the outer pipe over the work-hardened inner pipe.
Inventors
- 👤 Edward S. Goetze
- 👤 Frank Kennedy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:12
CPC Classifications
B; B21; B21C; B21C1/00; B21C1/16; B21C1/22; B21C37/00; B21C37/06; B21C37/15; B21C37/154; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49544; Y10T29/49547; Y10T29/49549; Y10T29/4956; Y10T29/49563; Y10T29/49789; Y10T29/49798; Y10T29/49826; Y10T29/49908; Y10T29/49925; Y10T29/49927; Y10T29/49934
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
179 words
A method for producing a composite metal pipe consisting essentially of selecting a first pipe member made of a drawable and work-hardneable metal, cold sink drawing said first pipe member through a first die having a die angle no greater than 30° to work-harden the microstructure thereof, selecting a second pipe member made of a work-hardenable metal having a hardness which is less than the hardness of the work-hardened first pipe member and having an inside diameter larger than the outside diameter of the work-hardened first pipe member, telescoping said second pipe member over said first pipe member, and cold sink drawing the telescoped pipe members through a second die having a die angle no greater than 30° to stretch and compress said second pipe member tightly over the first pipe member to form a composite pipe thereof such that the weight per unit length of said second pipe member is reduced at least about 10% but not more than 50% and the weight per unit length of said first pipe member is reduced from about 3 to 5%.
Claim 2
Independent Claim
179 words
A method for producing a composite metal pipe consisting essentially of selecting a first pipe member made of a drawable and work-hardneable metal, cold sink drawing said first pipe member through a first die having a die angle no greater than 30° to work-harden the microstructure thereof, selecting a second pipe member made of a work-hardenable metal having a hardness which is less than the hardness of the work-hardened first pipe member and having an inside diameter larger than the outside diameter of the work-hardened first pipe member, telescoping said second pipe member over said first pipe member, and cold sink drawing the telescoped pipe members through a second die having a die angle no greater than 30° to stretch and compress said second pipe member tightly over the first pipe member to form a composite pipe thereof such that the weight per unit length of said second pipe member is reduced at least about 10% but not more than 50% and the weight per unit length of said first pipe member is reduced from about 3 to 5%.
Claim 3
Dependent Claim
25 words
A method according to claim 1 in which said first and second pipe members have a hardness of less than 95Rb prior to any work-hardening.
Claim 4
Dependent Claim
20 words
A method according to claim 1 in which said first and second dies have die angles no greater than 15°.
Claim 5
Dependent Claim
63 words
A method according to claim 1 in which said first and second pipe members have diameters greater than about 2 inches but less than about 6 inches, and when telescoped prior to sink drawing the second pipe member, the inside diameter of said second pipe member is from about 1/8 to 1/4 inch larger than the outside diameter of said first pipe member.
Claim 6
Dependent Claim
29 words
A method according to claim 1 in which said first pipe member is made of a ferrous alloy and said second pipe member is made of a non-ferrous metal.
Claim 7
Dependent Claim
29 words
A method according to claim 5 in which said first pipe member is made of a stainless steel and said second pipe member is made of commercially pure nickel.
Claim 8
Independent Claim
185 words
A method for producing a composite metal roller for a roller hearth annealing furnace consisting essentially of selecting a first pipe member made of a stainless steel suitable for service at elevated temperatures, cold sink drawing said first pipe member through a first die having a die angle no greater than 30° to work-harden the microstructure thereof, selecting a second pipe member made essentially of nickel and having an inside diameter larger than the outside diameter of the work-hardened first pipe member, telescoping said second pipe member over said first pipe member, cold sink drawing the telescoped pipe members through a second die having a die angle no greater than 30° to stretch and compress said second pipe member tightly over the first pipe member to form a composite pipe thereof such that the weight per unit length of said second pipe member is reduced at least about 10% but not more than 50% and the weight per unit length of said first pipe member is reduced from about 3 to 5%, and cutting the composite pipe to the desired length for service as rollers.
Claim 9
Independent Claim
185 words
A method for producing a composite metal roller for a roller hearth annealing furnace consisting essentially of selecting a first pipe member made of a stainless steel suitable for service at elevated temperatures, cold sink drawing said first pipe member through a first die having a die angle no greater than 30° to work-harden the microstructure thereof, selecting a second pipe member made essentially of nickel and having an inside diameter larger than the outside diameter of the work-hardened first pipe member, telescoping said second pipe member over said first pipe member, cold sink drawing the telescoped pipe members through a second die having a die angle no greater than 30° to stretch and compress said second pipe member tightly over the first pipe member to form a composite pipe thereof such that the weight per unit length of said second pipe member is reduced at least about 10% but not more than 50% and the weight per unit length of said first pipe member is reduced from about 3 to 5%, and cutting the composite pipe to the desired length for service as rollers.
Claim 10
Dependent Claim
25 words
A method according to claim 7 in which said first and second pipe members have a hardness of less than 95Rb prior to any work-hardening.
Claim 11
Dependent Claim
20 words
A method according to claim 7 in which said first and second dies have die angles of less than 15°.
Claim 12
Dependent Claim
63 words
A method according to claim 7 in which said first and second pipe members have diameters greater than about 2 inches but less than about 6 inches, and when telescoped prior to sink drawing the second pipe member, the inside diameter of said second pipe member is from about 1/8 to 1/4 inch larger than the outside diameter of said first pipe member.
Claim 13
Dependent Claim
19 words
A method according to claim 7 in which said first pipe member is made of Type 330 stainless steel.
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) | 1981-11-20 | 1982-05-22 | 1982-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-20 | 1986-05-22 | 1986-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-20 | 1990-05-22 | 1990-11-21 | $7700.00 | Window Closed / Lapsed |