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US4613367A Expired / Lapsed US ⏱️ 0.0 years remaining

Low carbon plus nitrogen, free-machining austenitic stainless steel

Assignee: Crucible Materials Corp
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Filing: 1985-06-14
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Granted: 1986-09-23
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Expires: 2005-06-14
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Abstract

Abstract A chromium-nickel austenitic stainless steel having improved machinability resulting from low carbon and nitrogen contents, along with a high manganese to sulfur ratio. The composition of the steel consists essentially of, in weight percent, carbon plus nitrogen up to 0.060, preferably up to 0.049, and most preferred up to 0.032, chromium 16 to 30, preferred 17 to 19, nickel 5 to 26, preferred 6 to 14, sulfur 0.25 to 0.45, manganese over 2 to about 7 and at least about eight times the sulfur content, balance iron and incidental impurities.

Inventors

  • 👤 John J. Eckenrod
  • 👤 Kenneth E. Pinnow
  • 👤 Geoffrey O. Rhodes
  • 👤 William E. Royer

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 07:20
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/40; C22C38/58; C22C38/60

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 70 words
A free-machining, austentic stainless steel consisting of, in weight percent, carbon plus nitrogen both present having a total of up to 0.060 chromium 16 to 30 nickel 5 to 26 sulfur 0.25 to 0.45 manganese over 2 to about 7 and is at least about 8 times the sulfur content silicon up to about 1 phosphorous up to about 0.50 molybdenum up to about 0.60 iron balance with incidental impurities.
Claim 2
Dependent Claim 70 words
A free-machining, austentic stainless steel consisting of, in weight percent, carbon plus nitrogen both present having a total of up to 0.060 chromium 16 to 30 nickel 5 to 26 sulfur 0.25 to 0.45 manganese over 2 to about 7 and is at least about 8 times the sulfur content silicon up to about 1 phosphorous up to about 0.50 molybdenum up to about 0.60 iron balance with incidental impurities.
Claim 3
Dependent Claim 12 words
The steel of claim 1 having carbon plus nitrogen up to 0.049.
Claim 4
Dependent Claim 12 words
The steel of claim 1 having carbon plus nitrogen up to 0.032.
Claim 5
Dependent Claim 66 words
A free-machining, austentic stainless steel consisting of, in weight precent, carbon plus nitrogen both present having a total of up to 0.060 chromium 17 to 19 nickel 6 to 14 sulfur 0.25 to 0.45 silicon up to about 1 molybdenum up to about 0.60 manganese from over 2 to about 7 percent and is at least 8 times the sulfur content iron balance with incidental impurities.
Claim 6
Dependent Claim 66 words
A free-machining, austentic stainless steel consisting of, in weight precent, carbon plus nitrogen both present having a total of up to 0.060 chromium 17 to 19 nickel 6 to 14 sulfur 0.25 to 0.45 silicon up to about 1 molybdenum up to about 0.60 manganese from over 2 to about 7 percent and is at least 8 times the sulfur content iron balance with incidental impurities.
Claim 7
Dependent Claim 12 words
The steel of claim 4 having carbon plus nitrogen up to 0.049.
Claim 8
Dependent Claim 12 words
The steel of claim 4 having carbon plus nitrogen up to 0.032.
Claim 9
Dependent Claim 10 words
The steel of claim 4 having nickel 6.5 to 10.
Claim 10
Dependent Claim 12 words
The steel of claim 7 having carbon plus nitrogen up to 0.049.
Claim 11
Dependent Claim 12 words
The steel of claim 7 having carbon plus nitrogen up to 0.032.

References Cited (Backward Citations)

US3437478A Cited
US3888659A Cited
US3902898A Cited
US4444588A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-09-22 1990-03-24 1990-09-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-09-22 1994-03-24 1994-09-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-09-22 1998-03-24 1998-09-23 $7700.00 Window Closed / Lapsed

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