US4168190A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for locally solution-treating stainless material
Assignee: Dai Ichi High Frequency Co Ltd
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Filing: 1977-04-27
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Granted: 1979-09-18
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Expires: 1997-04-27
Abstract
Abstract A method and apparatus for treating stainless steel material to reduce the carbon precipitation of the grain boundaries of the material as a result of temperature elevation due to welding, mechanical bending, or the like. The treatment includes the rapid heating of the material to the temperature at which the carbon will enter into solid solution followed by a rapid quenching of the heated material. Beneficial stress modifications are also achieved.
Inventors
- 👤 Toshiyuki Eguchi
- 👤 Yoshihiro Imoto
- 👤 Kouji Kurose
- 👤 Masanori Terasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:30
CPC Classifications
C; C21; C21D; C21D6/00; C21D6/002; C21D9/00; C21D9/50
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
72 words
A method for locally solution treating austenitic stainless material which has been partially sensitized, as by a local rise in temperature, without creating a sensitized structure at the thermal boundaries between the locally treated portion and the remainder of the material, comprising the steps of: (a) rapidly heating the sensitized portions of the material to a temperature at which carbide will enter into solid solution; and (b) rapidly quenching the heated material.
Claim 2
Independent Claim
72 words
A method for locally solution treating austenitic stainless material which has been partially sensitized, as by a local rise in temperature, without creating a sensitized structure at the thermal boundaries between the locally treated portion and the remainder of the material, comprising the steps of: (a) rapidly heating the sensitized portions of the material to a temperature at which carbide will enter into solid solution; and (b) rapidly quenching the heated material.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein the total treating time is determined as a function of the carbon content of the stainless material.
Claim 4
Dependent Claim
17 words
The method of claim 1 wherein the rapid heating of the stainless material is by induction heating.
Claim 5
Dependent Claim
23 words
The method of claim 1 wherein the quenching of the stainless material is by contact of at least one surface thereof with water.
Claim 6
Dependent Claim
27 words
The method of claim 1 including the step of heat treating the stainless material to improve the structure of the material prior to steps (a) and (b).
Claim 7
Independent Claim
93 words
A method of locally solution treating austenitic stainless material previously sensitized by heating without creating a sensitized structure at the thermal boundaries between the locally treated portion and the remainder of the material, comprising the steps of: (a) induction heating the stainless material to a temperature at which carbon will enter into solid solution; (b) rapidly quenching the heated material by the application of a cooling liquid to one surface thereof; and, (c) the total time period of the treatment being variable as a function of the carbon content of the stainless material.
Claim 8
Independent Claim
93 words
A method of locally solution treating austenitic stainless material previously sensitized by heating without creating a sensitized structure at the thermal boundaries between the locally treated portion and the remainder of the material, comprising the steps of: (a) induction heating the stainless material to a temperature at which carbon will enter into solid solution; (b) rapidly quenching the heated material by the application of a cooling liquid to one surface thereof; and, (c) the total time period of the treatment being variable as a function of the carbon content of the stainless material.
References Cited (Backward Citations)
US2246445A
Cited
US2888373A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-09-17 | 1983-03-19 | 1983-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-17 | 1987-03-19 | 1987-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-17 | 1991-03-19 | 1991-09-18 | $7700.00 | Window Closed / Lapsed |