US4769213A
Expired / Lapsed
US
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Age-hardenable stainless steel having improved machinability
Assignee: Crucible Materials Corp
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Filing: 1986-08-21
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Granted: 1988-09-06
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Expires: 2006-08-21
Abstract
Abstract A chromium-nickel-copper, age-hardenable martensitic stainless steel having improved machinability in the solution-treated and also in the age-hardened condition. The steel has carbon plus nitrogen up to 0.08%, preferably 0.05 or 0.035% for purposes of improved machinability.
Inventors
- 👤 Walter T. Haswell, Jr.
- 👤 Kenneth E. Pinnow
- 👤 Geoffrey O. Rhodes
- 👤 John J. Eckenrod
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:20
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/40; C22C38/42
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
116 words
A chromium-nickel-copper, age-hardenable martensitic stainless steel characterized by having improved machinability in both the solution-treated and age-hardened conditions and stress corrosion cracking resistance after aging, said steel consisting essentially of, in weight percent: carbon plus nitrogen up to 0.05 manganese up to 8.0 phosphorus up to 0.040 sulfur up to 0.15 silicon up to 1.0 nickel 2.00 to 5.50 chromium 11.00 to 17.50 molybdenum up to 3.0 copper 2.00 to 5.00 columbium 0.19% to 15 x (C+N) aluminum up to 0.05 balance iron with incidental impurities, with the composition of said steel being balanced to have both no delta ferrite according to equation (1) and an M s temperature above 250° F. according to equation (2).
Claim 2
Dependent Claim
116 words
A chromium-nickel-copper, age-hardenable martensitic stainless steel characterized by having improved machinability in both the solution-treated and age-hardened conditions and stress corrosion cracking resistance after aging, said steel consisting essentially of, in weight percent: carbon plus nitrogen up to 0.05 manganese up to 8.0 phosphorus up to 0.040 sulfur up to 0.15 silicon up to 1.0 nickel 2.00 to 5.50 chromium 11.00 to 17.50 molybdenum up to 3.0 copper 2.00 to 5.00 columbium 0.19% to 15 x (C+N) aluminum up to 0.05 balance iron with incidental impurities, with the composition of said steel being balanced to have both no delta ferrite according to equation (1) and an M s temperature above 250° F. according to equation (2).
Claim 3
Dependent Claim
10 words
The steel of claim 1 having up to 0.030 sulfur.
Claim 4
Dependent Claim
116 words
A chromium-nickel-copper, age-hardenable martensitic stainless steel characterized by having improved machinability in both the solution-treated and age-hardened conditions and stress corrosion cracking resistance after aging, said steel consisting essentially of, in weight percent: carbon plus nitrogen up to 0.05 manganese up to 2.0 phosphorus up to 0.040 sulfur up to 0.15 silicon up to 1.0 nickel 2.00 to 5.50 chromium 11.00 to 17.50 molybdenum up to 0.50 copper 2.00 to 5.00 columbium 0.19% to 15 x (C+N) aluminum up to 0.05 balance iron with incidental impurities, with the composition of said steel being balanced to have both no delta ferrite according to equation (1) and an M s temperature above 250° F. according to equation (2).
Claim 5
Dependent Claim
116 words
A chromium-nickel-copper, age-hardenable martensitic stainless steel characterized by having improved machinability in both the solution-treated and age-hardened conditions and stress corrosion cracking resistance after aging, said steel consisting essentially of, in weight percent: carbon plus nitrogen up to 0.05 manganese up to 2.0 phosphorus up to 0.040 sulfur up to 0.15 silicon up to 1.0 nickel 2.00 to 5.50 chromium 11.00 to 17.50 molybdenum up to 0.50 copper 2.00 to 5.00 columbium 0.19% to 15 x (C+N) aluminum up to 0.05 balance iron with incidental impurities, with the composition of said steel being balanced to have both no delta ferrite according to equation (1) and an M s temperature above 250° F. according to equation (2).
Claim 6
Dependent Claim
10 words
The steel of claim 3 having up to 0.030 sulfur.
Claim 7
Dependent Claim
117 words
A chromium-nickel-copper, age-hardenable martensitic stainless steel mold characterized by having improved machinability in both the solution-treated and age-hardened conditions and stress corrosion cracking resistance after aging, said mold consisting essentially of, in weight percent: carbon plus nitrogen up to 0.05 manganese up to 8.0 phosphorus up to 0.040 sulfur up to 0.15 silicon up to 1.0 nickel 2.00 to 5.50 chromium 11.00 to 17.50 molybdenum up to 3.0 copper 2.00 to 5.00 columbium 0.19% to 15 x (C+N) aluminum up to 0.05 balance iron with incidental impurities, with the composition of said mold being balanced to have both no delta ferrite according to equation (1) and an M s temperature above 250° F. according to equation (2).
Claim 8
Dependent Claim
117 words
A chromium-nickel-copper, age-hardenable martensitic stainless steel mold characterized by having improved machinability in both the solution-treated and age-hardened conditions and stress corrosion cracking resistance after aging, said mold consisting essentially of, in weight percent: carbon plus nitrogen up to 0.05 manganese up to 8.0 phosphorus up to 0.040 sulfur up to 0.15 silicon up to 1.0 nickel 2.00 to 5.50 chromium 11.00 to 17.50 molybdenum up to 3.0 copper 2.00 to 5.00 columbium 0.19% to 15 x (C+N) aluminum up to 0.05 balance iron with incidental impurities, with the composition of said mold being balanced to have both no delta ferrite according to equation (1) and an M s temperature above 250° F. according to equation (2).
Claim 9
Dependent Claim
11 words
The steel mold of claim 5 having up to 0.030 sulfur.
Claim 10
Dependent Claim
115 words
A chromium-nickel-copper, age-hardenable martensitic stainless steel mold characterized by having improved machinability in both the solution-treated and age-hardened conditions and stress corrosion cracking resistance after aging, consisting essentially of, in weight percent: carbon plus nitrogen up to 0.05 manganese up to 2.0 phosphorus up to 0.040 sulfur up to 0.15 silicon up to 1.0 nickel 2.00 to 5.50 chromium 11.00 to 17.50 molybdenum up to 0.50 copper 2.00 to 5.00 columbium 0.19% to 15 x (C+N) aluminum up to 0.05 balance iron with incidental impurities, with the composition of said mold being balanced to have both no delta ferrite according to equation (1) and an M s temperature above 250° F. according to equation (2).
Claim 11
Dependent Claim
115 words
A chromium-nickel-copper, age-hardenable martensitic stainless steel mold characterized by having improved machinability in both the solution-treated and age-hardened conditions and stress corrosion cracking resistance after aging, consisting essentially of, in weight percent: carbon plus nitrogen up to 0.05 manganese up to 2.0 phosphorus up to 0.040 sulfur up to 0.15 silicon up to 1.0 nickel 2.00 to 5.50 chromium 11.00 to 17.50 molybdenum up to 0.50 copper 2.00 to 5.00 columbium 0.19% to 15 x (C+N) aluminum up to 0.05 balance iron with incidental impurities, with the composition of said mold being balanced to have both no delta ferrite according to equation (1) and an M s temperature above 250° F. according to equation (2).
Claim 12
Dependent Claim
11 words
The steel mold of claim 7 having up to 0.030 sulfur.
Claim 13
Dependent Claim
16 words
The steel of claims 1, or 2, or 3, or 4 having up to 0.5 beryllium.
Claim 14
Dependent Claim
17 words
The steel mold of claims 5, or 6, or 7, or 8 having up to 0.5 beryllium.
Claim 15
Dependent Claim
16 words
The steel mold of claim 7 having 2.50 to 3.50 nickel and 11.00 to 13.00 chromium.
Claim 16
Dependent Claim
11 words
The steel mold of claim 11 having up to 0.030 sulfur.
References Cited (Backward Citations)
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JPS4827569A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-06 | 1992-03-07 | 1992-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-06 | 1996-03-07 | 1996-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-06 | 2000-03-07 | 2000-09-06 | $7700.00 | Window Closed / Lapsed |