US3849209A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacturing method of high tension, high toughness steel
Assignee: Nippon Steel Corp
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Filing: 1973-10-11
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Granted: 1974-11-19
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Expires: 1993-10-11
Abstract
Abstract Method for obtaining a recrystallized austenite structure in steel by carrying out more than one severe reduction per pass between 1,100*C and 950*C in the hot rolling process of a steel comprising 0.005 - 0.15% C, less than 0.6% Si, 0.70 - 2.0% Mn and 0.01 - 0.15% Nb and containing other effective elements if necessary, with the remainder being essentially Fe, and then rolling the steel to obtain a high toughness, high tension steel plates and strips.
Inventors
- 👤 G Kanbayashi
- 👤 T Maruyama
- 👤 T Kawano
- 👤 H Watanabe
- 👤 H Gondo
- 👤 K Wada
- 👤 K Ishizaki
- 👤 H Sekine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:50
CPC Classifications
C; C21; C21D; C21D8/00; C21D8/02; C21D8/0221; C21D8/0226
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
163 words
A METHOD FOR MANUFACTURING A HIGH TENSION, HIGH TOUGHNESS STEEL COMPRISING HOT-ROLLING A STELL COMPOSITION COMPOSED OF: 0.005 - 0.15% C. LESS THAN 0.60% SI, 0.70 - 2.0% MN, 0.01 - 0.15% SI, O TO LESS THAN 0.20% V, O TO LESS THAN 0.08% AL, O TO LESS THAN 1.00% NI, 0 TO LESS THAN 1.00% CR, 0 TO LESS THAN 1.00% CU, 0 TO LESS THAN 0.20% TI, AND 0 TO LESS THAN 0.20% ZN, WITH THE REMAINDER BEING IRON AND UNAVOIDABLE IMPURITIES, AND WHEREIN SAID HOT ROLLING IS CARRIED OTH AFTER HEATING TO A TEMPERATURE OF HIGHER THAN 1,200*C, AND DURING SAID HOT ROLLING, AT LEAST ONE SEVERE REDUCTION AT A RATE OF MORE THAN 26 PERCENT PER PASS IS EFFECTED IN THE TEMPERATURE RANGE FROM 1,100*C TO 950*C, AND WHEREIN THE TOTAL REDUCTION BELOW 950*C, IN MORE THAN 45 PERCENT OF THE PLATE THICKNESS AT 950*, AND THEN FINISHING AT A TEMPERATURE BELOW 850:C AND ABOVE THE AR3 TRANSFORMATION POINT.
Claim 2
Independent Claim
163 words
A METHOD FOR MANUFACTURING A HIGH TENSION, HIGH TOUGHNESS STEEL COMPRISING HOT-ROLLING A STELL COMPOSITION COMPOSED OF: 0.005 - 0.15% C. LESS THAN 0.60% SI, 0.70 - 2.0% MN, 0.01 - 0.15% SI, O TO LESS THAN 0.20% V, O TO LESS THAN 0.08% AL, O TO LESS THAN 1.00% NI, 0 TO LESS THAN 1.00% CR, 0 TO LESS THAN 1.00% CU, 0 TO LESS THAN 0.20% TI, AND 0 TO LESS THAN 0.20% ZN, WITH THE REMAINDER BEING IRON AND UNAVOIDABLE IMPURITIES, AND WHEREIN SAID HOT ROLLING IS CARRIED OTH AFTER HEATING TO A TEMPERATURE OF HIGHER THAN 1,200*C, AND DURING SAID HOT ROLLING, AT LEAST ONE SEVERE REDUCTION AT A RATE OF MORE THAN 26 PERCENT PER PASS IS EFFECTED IN THE TEMPERATURE RANGE FROM 1,100*C TO 950*C, AND WHEREIN THE TOTAL REDUCTION BELOW 950*C, IN MORE THAN 45 PERCENT OF THE PLATE THICKNESS AT 950*, AND THEN FINISHING AT A TEMPERATURE BELOW 850:C AND ABOVE THE AR3 TRANSFORMATION POINT.
Claim 3
Dependent Claim
22 words
The method of claim 1, wherein the total reduction below 850*C is less than 30 percent of the plate thickness at 850*C.
Claim 4
Dependent Claim
23 words
The method of claim 1, wherein, after finishing the hot rolling, the product is coiled in the temperature range between 680*C and 500*C.
Claim 5
Dependent Claim
23 words
The method of claim 2 wherein, after finishing the hot rolling, the product is coiled in the temperature range between 680*C and 500*C.
Claim 6
Dependent Claim
21 words
The method of claim 1 wherein, after finishing the hot rolling, the product is coiled in the temperature range above 700*C.
References Cited (Backward Citations)
US3328211A
Cited
US3645801A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |