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US4836848A
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US
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Fe-based sintered alloy for valve seats for use in internal combustion engines
Assignee: Mitsubishi Metal Corp
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Filing: 1987-10-02
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Granted: 1989-06-06
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Expires: 2007-10-02
Abstract
Abstract An Fe-base sintered alloy for valve seats for use in internal combustion engines and a method of manufacturing the same are provided. The alloy consists essentially of 0.6 to 1.3% C, 1 to 5% Cr, 4 to 15% Mo, 0.5 to 2% Ni, 2 to 8% Co, 0.2 to 2% Nb, 0.2 to 2% at least one lubricating component selected from the group consisting of a CaF2 and BaF2 and the balance of Fe and inevitable impurities. Starting powders are blended into the same composition as above, and mixed into a mixed powder. The mixed powder is pressed into a green compact. Then, the green compact is presintered, hot forged, sintered, and, if required, further heat treated, in sequence to be formed into an Fe-base sintered alloy having a structure wherein particles of the at least one lubricating component and hard particles of other components are dispersed in a matrix formed principally of a pearlite phase. The resulting alloy possesses a density of at least 7.3 g/cm3 and Rockwell handness of 30-50 in Rockwell Scale C, and hence exhibits excellent abrasion resistance as well as excellent lubricity.
Inventors
- 👤 Osamu Mayama
- 👤 Yoshimi Ishikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:30
CPC Classifications
C; C22; C22C; C22C33/00; C22C33/02; C22C33/0257; C22C33/0278; C22C33/0207; C22C33/0228; F; F01; F01L; F01L3/00; F01L3/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
133 words
An Fe-base sintered alloy for valve seats for use in internal combustion engines, consisting essentially of the following components: 0.6 to 1.3% C; 1 to 5% Cr; 4 to 15% Mo; 0.5 to 2% Ni; 2 to 8% Co; 0.2 to 2% Nb; 0.2 to 2% at least one lubricating component selected from the group consisting of CaF 2 and BaF 2 ; and the balance of Fe and inevitable impurities; said Fe-base sintered alloy having a structure wherein (i) particles of said at least one lubricating component and (ii) hard particles formed of other of said components, are dispersed in a matrix comprising 50 to 90 volume % of a pearlite phase, and said alloy possessing a density of at least 7.3 g/cm 3 and Rockwell hardness of 30-50 in Scale C.
Claim 2
Dependent Claim
133 words
An Fe-base sintered alloy for valve seats for use in internal combustion engines, consisting essentially of the following components: 0.6 to 1.3% C; 1 to 5% Cr; 4 to 15% Mo; 0.5 to 2% Ni; 2 to 8% Co; 0.2 to 2% Nb; 0.2 to 2% at least one lubricating component selected from the group consisting of CaF 2 and BaF 2 ; and the balance of Fe and inevitable impurities; said Fe-base sintered alloy having a structure wherein (i) particles of said at least one lubricating component and (ii) hard particles formed of other of said components, are dispersed in a matrix comprising 50 to 90 volume % of a pearlite phase, and said alloy possessing a density of at least 7.3 g/cm 3 and Rockwell hardness of 30-50 in Scale C.
Claim 3
Dependent Claim
17 words
A valve seat for use in internal combustion engines comprising the Fe-base sintered alloy of claim 1.
Claim 4
Dependent Claim
61 words
The valve seat as claimed in claim 2 wherein said alloy consists essentially of 0.9 to 1.1% C; 2 to 3% Cr; 5 to 8% Mo; 0.5 to 1.5% Ni; 3 to 5% Co; 0.7 to 1.2% Nb and 0.7 to 1.3% of said at least one lubricating components; said alloy having a Rockwell hardness of 35-45 on the C scale.
Claim 5
Dependent Claim
86 words
The valve seat according to claim 3 wherein said matrix of said alloy contains at least 50 volume % said pearlite phase; and wherein said alloy consists essentially of: 2 to 20 volume % a disperse phase formed of said at least one lubricating component and said hard particles; 50 to 90 volume % said pearlite phase, 1 to 20 volume % a martensite phase, 5 volume % or less an austenite phase, and the balance of a ferrite phase, all said phases forming said matrix.
Claim 6
Dependent Claim
72 words
An Fe-base sintered alloy as claimed in claim 1, wherein said alloy consists essentially of: 2 to 20 volume % a disperse phase formed of said at least one lubricating component and said hard particles; 50 to 90 volume % said pearlite phase, 1 to 20 volume % a martensite phase, 5 volume % or less an austenite phase, and the balance of a ferrite phase, all said phases forming said matrix.
Claim 7
Dependent Claim
61 words
An Fe-base sintered alloy as claimed in claim 5, wherein said alloy consists essentially of 0.9 to 1.1%C; 2 to 3% Cr; 5 to 8% Mo; 0.5 to 1.5% Ni; 3 to 5% Co; 0.7 to 1.3% Nb and 0.7 to 1.2% of said at least one lubricating components; said alloy having a Rockwell hardness of 35-45 on the C scale.
Claim 8
Dependent Claim
62 words
An Fe-base sintered alloy as claimed in claim 1, wherein said alloy consists essentially of 0.9 to 1.1% C; 2 to 3% Cr; 5 to 8% Mo; 0.5 to 1.5% Ni; 3 to 5% Co; 0.7 to 1.3% Nb and 0.7 to 1.2% of said at least one lubricating components; said alloy having a Rockwell hardness of 35-45 on the C scale.
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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) | 1992-06-05 | 1992-12-05 | 1993-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-05 | 1996-12-05 | 1997-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-05 | 2000-12-05 | 2001-06-06 | $7700.00 | Window Closed / Lapsed |