US3650848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of ferritic stainless steel with improved drawing properties
Assignee: J and L Specialty Products Corp
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Filing: 1969-06-18
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Granted: 1972-03-21
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Expires: 1989-06-18
Abstract
Abstract Ferritic stainless steel of the 430 series is produced to have improved drawing properties by procedure in which in a two-stage cold reduction of the hot-rolled band, with an intermediate anneal, the second stage effects reduction of at least about 80 percent, following at least about 30 percent reduction in the first stage. The finally annealed sheet is substantially nonearing and when the first stage reduction is at least in the vicinity of 40 percent, the sheet is also characterized by deep drawing property.
Inventors
- 👤 Stephen G Schneider
- 👤 Frank A Hultgren
- 👤 William F Barclay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:19
CPC Classifications
C; C21; C21D; C21D8/00; C21D8/02; C21D8/04
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
38 words
A method as defined in claim 1 for producing sheet having deep drawing property represented by an r value greater than 1.4, in which said first stage consists in cold reducing the steel by at least about 40%.
Claim 2
Dependent Claim
63 words
A method as defined in claim 1, in which said stainless steel contains about 16 to 17.5 percent chromium, not more than about 0.3 percent nickel and not more than about 0.12 percent carbon, and in which said first and second cold-rolling stages are respectively effected to reductions of substantially more than 35 percent and in the range of 80 percent and above.
Claim 3
Dependent Claim
15 words
A method as defined in claim 3, in which said stainless steel is type 430.
Claim 4
Dependent Claim
15 words
A method as defined in claim 3, in which said stainless steel is type 434.
Claim 5
Dependent Claim
15 words
A method as defined in claim 3, in which said stainless steel is type 436.
Claim 6
Independent Claim
94 words
A method of producing deep drawing, substantially non-earing sheet from ferritic stainless steel of the 430 series which has been hot rolled and annealed, comprising cold rolling the steel, to a reduction of more than 35 percent, then intermediate annealing, then cold rolling the steel to a further reduction of at least about 80 percent, and finally annealing the cold-reduced steel to produce the aforesaid deep drawing sheet, the cold rolling reduction of said hot rolled and annealed steel consisting of the aforesaid two stages of cold reduction interrupted only by said intermediate anneal.
Claim 7
Dependent Claim
68 words
A method as defined in claim 7, in which said stainless steel contains about 16 to 17.5 percent chromium, not more than about 0.3 percent nickel and not more than about 0.12 percent carbon, and in which said first cold-rolling stage is effected to a reduction substantially greater than 35 percent to produce a final sheet having deep drawing property represented by an r value greater than 1.4.
Claim 8
Dependent Claim
23 words
A method as defined in claim 7, in which said first cold-rolling stage is effected to a reduction of at least about 40%.
Claim 9
Dependent Claim
54 words
A method as defined in claim 7 for producing substantially non-earing sheet having deep drawing property represented by an r value of at least about 1.5, in which said first and second cold-rolling stages are respectively effected to reductions of at least about 40 percent and in the range of 80 percent and above.
Claim 10
Independent Claim
145 words
A method of producing substantially non-earing sheet from straight chromium ferritic stainless steel containing about 16 to about 18 percent chromium, comprising continuously hot rolling said steel from slab to a hot band of thickness not greater than about 0.2 inch, annealing said hot band, cold rolling said band in a first stage to a reduction of at least about 30 percent, then intermediate annealing the resulting strip, then cold rolling said strip in a second stage to a reduction in the range of about 80 percent and above to provide a value of Delta r/r of the final sheet not substantially greater than about 0.2, and finally annealing the cold-reduced steel from the second stage to produce the aforesaid substantially non-earing sheet, the cold rolling reduction of said annealed hot band consisting of said first and second stages interrupted only by said intermediate anneal.
Claim 11
Dependent Claim
45 words
A method as defined in claim 11, for producing deep drawing sheet, in which said first cold-rolling stage is effected to a reduction in the range of about 40 percent and above a value of r in the final sheet of at least about 1.5.
Claim 12
Dependent Claim
36 words
A method as defined in claim 12, in which said hot band annealing, said intermediate annealing and said final annealing are effected at temperatures in the range of at least about 1, 450* F. and above.
Claim 13
Dependent Claim
52 words
Stainless steel sheet consisting of straight chromium ferritic stainless steel containing 14 to 18 percent chromium, having deep drawability without substantial earing and having an r value of at least about 1.4 and a value of Delta r/r of substantially less than about 0.3, and produced by the method of claim 7.
Claim 14
Dependent Claim
69 words
Stainless steel sheet consisting of straight chromium ferritic stainless steel containing about 16 to about 18 percent chromium, not more than about 0.12 percent carbon and not more than about 0.3 percent nickel, having deep drawability without substantial earing and having an r value of at least about 1.5 and a value of Delta r/r not substantially greater than about 0.2 and produced by the method of claim 12.
References Cited (Backward Citations)
US2772992A
Cited
US2808353A
Cited
US3067072A
Cited
US3139358A
Cited
US3128211A
Cited
US3490956A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |