US4906305A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a composite drawn article
Assignee: Allegheny Ludlum Corp
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Filing: 1988-08-18
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Granted: 1990-03-06
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Expires: 2008-08-18
Abstract
Abstract To obtain a composite material which has a substantially reduced incidence of defects after forming, there is made a composite having at least one layer of plain-carbon steel and, between it and a layer of stainless steel, an interleaving layer of silicon steel.
Inventors
- 👤 Ronald J. McCormick
- 👤 G. Leonard Yeager
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:49
CPC Classifications
B; B32; B32B; B32B15/00; B32B15/01; B32B15/011; B32B15/18
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
173 words
A method of making a composite drawn article comprised of at least a central stratum of plain-carbon steel and two exterior strata of stainless steel, said method comprising the steps of: forming an article which contains a central stratum of plain-carbon steel and two exterior strata of stainless steel, with interleaving strata between said exterior strata and said stratum of plain-carbon steel, said interleaving strata being of steel containing more than 0.50 and up to 4.5 weight percent silicon, and said interleaving strata having between them a thickness of less than 25 percent of that of the entire article; hot rolling said article at a temperature in excess of 1600 degrees F. so as to form a bond therebetween and thereby produce a composite; cold rolling said composite; annealing the cold-rolled composite at a temperature in excess of 1800 degrees F., said composite having a yield strength at 0.2 percent offset of under 50,000 pounds per square inch; and forming by deep drawing the annealed composite, thereby producing a composite deep drawn article.
Claim 2
Independent Claim
173 words
A method of making a composite drawn article comprised of at least a central stratum of plain-carbon steel and two exterior strata of stainless steel, said method comprising the steps of: forming an article which contains a central stratum of plain-carbon steel and two exterior strata of stainless steel, with interleaving strata between said exterior strata and said stratum of plain-carbon steel, said interleaving strata being of steel containing more than 0.50 and up to 4.5 weight percent silicon, and said interleaving strata having between them a thickness of less than 25 percent of that of the entire article; hot rolling said article at a temperature in excess of 1600 degrees F. so as to form a bond therebetween and thereby produce a composite; cold rolling said composite; annealing the cold-rolled composite at a temperature in excess of 1800 degrees F., said composite having a yield strength at 0.2 percent offset of under 50,000 pounds per square inch; and forming by deep drawing the annealed composite, thereby producing a composite deep drawn article.
Claim 3
Dependent Claim
16 words
A method as defined in claim 1, wherein said plain-carbon steel is AISI Type 1006 steel.
Claim 4
Dependent Claim
19 words
A method as defined in claim 1, wherein said stainless steel is a chromium-nickel or chromium-nickel-manganese austenitic stainless steel.
Claim 5
Dependent Claim
17 words
A method as defined in claim 3, wherein said stainless steel is AISI Type 304 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) | 1993-03-05 | 1993-09-04 | 1994-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-05 | 1997-09-04 | 1998-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-05 | 2001-09-04 | 2002-03-06 | $7700.00 | Window Closed / Lapsed |