US3660629A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for welding high tensile strength steel of higher strength
Assignee: Kanadevia Corp
•
Filing: 1970-01-02
•
Granted: 1972-05-02
•
Expires: 1990-01-02
Abstract
Abstract At first to execute a welding of high tensile strength steel of more than 60 kg/mm2 an electro-slag welding technique is adapted. While said electro-slag welding being operated, deposited metal near the molten weld metal and the base metal portion near thereto in hot state are subjected to high speed cooling by liquid so that they may be quenched, thereby to transform the bond structure into a structure comprising martensite and lower bainite or preferably into a martensitic structure. And then by tempering, said structure comprising martensite and lower bainite is changed into a structure comprising tempered martensite and tempered lower bainite and said martensitic structure is changed into a tempered martensitic structure.
Inventors
- 👤 Tuneo Nakai
- 👤 Akira Ando
- 👤 Setuzi Minehisa
- 👤 Shunsuke Kaneko
- 👤 Yosinori Siraki
- 👤 Tatuo Inui
- 👤 Hiroyuki Nakazima
- 👤 Naotugu Tominaga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:12
CPC Classifications
B; B23; B23K; B23K25/00; C; C21; C21D; C21D9/00; C21D9/50; C21D9/505
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
94 words
A method of welding quenched and tempered high tensile strength steel in excess of 60 kg/mm2 to prevent upper bainite structure from forming in the bond portion comprising the steps of: A. cooling the deposited metal produced by an electro-slag welding process and the base metal near thereto at high speed by means of liquid and at such rate that B. the bonded product produced is transformed into at least one of a structure including martensite and a structure including martensite and lower bainite and not including upper bainite, and tempering the resultant structure.
Claim 2
Independent Claim
94 words
A method of welding quenched and tempered high tensile strength steel in excess of 60 kg/mm2 to prevent upper bainite structure from forming in the bond portion comprising the steps of: A. cooling the deposited metal produced by an electro-slag welding process and the base metal near thereto at high speed by means of liquid and at such rate that B. the bonded product produced is transformed into at least one of a structure including martensite and a structure including martensite and lower bainite and not including upper bainite, and tempering the resultant structure.
Claim 3
Dependent Claim
36 words
A method as claimed in claim 1 including the further step wherein the cooling is achieved by pouring liquid onto the base metal adjacent to the weld area whereupon vaporization absorbs heat from the deposited metal.
Claim 4
Dependent Claim
30 words
A method as claimed in claim 2 including the further step wherein the cooling is achieved by pouring liquid on the deposited weld metal and thereupon removing the resultant slag.
Claim 5
Dependent Claim
38 words
A method as claimed in claim 2, including the further step of preventing vapor emanating upon the pouring of the liquid oNto the base metal adjacent to the weld area from flowing onto the molten weld metal surface.
Claim 6
Dependent Claim
40 words
A method as claimed in claim 4 including the further step wherein an inert gas curtain is formed between the pouring liquid and the molten weld metal, thereby preventing the said vapor from flowing onto the molten weld metal surface.
Claim 7
Dependent Claim
32 words
A method as claimed in claim 5, including the further step wherein the inert gas is emitted to the weld metal prior to introduction of the cooling liquid to the base metal.
Claim 8
Dependent Claim
60 words
A method as claimed in claim 4, wherein the cooling liquid is applied onto the base metal from one direction with respect to the molten weld metal and the vapor created thereby is sucked away in a direction opposite thereto also with respect to the molten weld metal, thereby preventing the vapor from flowing onto the molten weld metal surface.
Claim 9
Dependent Claim
36 words
A method as claimed in claim 3, comprising the further step of preventing vapors emanating from the pouring of the liquid onto the deposited weld metal and slag from flowing onto the molten weld metal surface.
Claim 10
Dependent Claim
27 words
A method as claimed in claim 8, wherein said vapors are prevented from flowing onto the molten weld metal surface by a curtain of an inert gas.
Claim 11
Dependent Claim
48 words
A method as claimed in claim 1, wherein the cooling speed is greater than the speed represented by a cooling curve passing the intersection of the bainite transformation starting line with the level line of 500* C. shown in the continuous cooling transformation diagram for the base metal.
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) | 1975-05-02 | 1975-11-01 | 1976-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-02 | 1979-11-01 | 1980-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-02 | 1983-11-01 | 1984-05-02 | $7700.00 | Window Closed / Lapsed |