US5221321A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fe-base sintered alloy for valve seats for use in internal combustion engines
Assignee: Hyundai Motor Co
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Filing: 1991-06-18
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Granted: 1993-06-22
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Expires: 2011-06-18
Abstract
Abstract A Fe-base sintered alloy for a valve seat for use in internal combustion engines, which constitutes a chemical composition of 0.4 to 2% of C, 0.5 to 5% of Cr, 5 to 15% of Mo, 0.2 to 2% of Ni, 0.4 to 2% of Co, 8 to 20% of Cu, 0.01 to 0.5% of S, and the balance Fe, wherein percentages are by weight. The Fe-base sintered alloy possesses high strength and high rigidity, and hence exhibits excellent abrasive and corrosion wear resistance properties, as well as excellent lubricity.
Inventors
- 👤 Jong Dae Lim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:54
CPC Classifications
C; C22; C22C; C22C33/00; C22C33/02; C22C33/0257; C22C33/0278
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
62 words
A Fe-base sintered alloy for a valve seat for use in internal combustion engines, which consists essentially of 0.4 to 2% of C, 0.5 to 5% of Cr, 5 to 15% of Mo, 0.2 to 2% of Ni, 0.4 to 2% of Co, 8 to 20% of Cu, 0.01 to 0.5% of S, and the balance Fe, wherein percentages are by weight.
Claim 2
Dependent Claim
62 words
A Fe-base sintered alloy for a valve seat for use in internal combustion engines, which consists essentially of 0.4 to 2% of C, 0.5 to 5% of Cr, 5 to 15% of Mo, 0.2 to 2% of Ni, 0.4 to 2% of Co, 8 to 20% of Cu, 0.01 to 0.5% of S, and the balance Fe, wherein percentages are by weight.
Claim 3
Dependent Claim
53 words
The Fe-base sintered ally of claim 1, wherein the C is derived from natural graphite, the Cr is from Fe-Cr alloy, the Mo is from Mo powder or Fe-Mo alloy, the Ni is metallic Ni, the Co is metallic Co, the Cu is from Co-Cu powder and the S is from Fe-S alloy.
Claim 4
Dependent Claim
115 words
A process for the preparation of Fe-base sintered alloy for a valve seat for use in internal combustion engines, which comprises: mixing, by weight, powders of 0.4 to 2% of C, 0.5 to 5% of Cr, 5 to 15% of Mo, 0.2 to 2% of Ni, 0.4 to 2% of Co, 8 to 20% of Cu, 0.01 to 0.5% of S, and the balance Fe to produce a first mixture; compacting said first mixture to produce a green compact; sintering said green compact at a temperature of about 1,000° to 1,200° C.; and reheating sintered products for infiltration, cooling it in oil, heating it again and then cooling it in air to produce the alloy.
Claim 5
Dependent Claim
115 words
A process for the preparation of Fe-base sintered alloy for a valve seat for use in internal combustion engines, which comprises: mixing, by weight, powders of 0.4 to 2% of C, 0.5 to 5% of Cr, 5 to 15% of Mo, 0.2 to 2% of Ni, 0.4 to 2% of Co, 8 to 20% of Cu, 0.01 to 0.5% of S, and the balance Fe to produce a first mixture; compacting said first mixture to produce a green compact; sintering said green compact at a temperature of about 1,000° to 1,200° C.; and reheating sintered products for infiltration, cooling it in oil, heating it again and then cooling it in air to produce the alloy.
Claim 6
Dependent Claim
51 words
The process of claim 3, wherein the C is derived from natural graphite, the Cr is from Fe-Cr alloy, the Mo is from Mo powder or Fe-Mo alloy, the Ni is metallic Ni, the Co is metallic Co, the Cu is from Co-Cu powder and the S is from Fe-S alloy.
References Cited (Backward Citations)
US3856478A
Cited
US3982905A
Cited
US4632074A
Cited
US4345943A
Cited
US4348232A
Cited
JPS563654A
Cited
JPS5620143A
Cited
US4505988A
Cited
US4546737A
Cited
US4671491A
Cited
US4734968A
Cited
JPS63100206A
Cited
US4836848A
Cited
KR900006700A
Cited
KR890003408A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-06-21 | 1996-12-21 | 1997-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-21 | 2000-12-21 | 2001-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-21 | 2004-12-21 | 2005-06-22 | $7700.00 | Window Closed / Lapsed |