US4414029A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Powder mixtures for wear resistant facings and products produced therefrom
Assignee: Kennametal PC Inc
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Filing: 1981-05-20
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Granted: 1983-11-08
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Expires: 2001-05-20
Abstract
Abstract This invention relates to mixtures of tungsten carbide, niobium metal, and molybdenum metal powders for use in the hardfacing of drill pipe couplings used in earth boring operations. It has been found that the addition of small amounts of niobium metal alone, or in combination with molybdenum, are effective to substantially submerge the tungsten carbide particles in the weld pool produced during hardfacing while, also, minimizing the occurrence of cracks which may be produced as the weld pool freezes.
Inventors
- 👤 Harold C. Newman
- 👤 William M. Stoll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:29
CPC Classifications
C; C23; C23C; C23C24/00; C23C24/08; C23C24/10; C23C24/103; B; B23; B23K; B23K35/00; B23K35/22; B23K35/24; B23K35/32; B23K35/327; C23C4/00; C23C4/04; C23C4/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
26 words
A mixture of hardfacing powders comprising: macrocrystalline WC particles; 0.05 to 0.5 weight percent niobium metal powder; and 0.05 to 1.0 weight percent molybdenum metal powders.
Claim 2
Dependent Claim
26 words
A mixture of hardfacing powders comprising: macrocrystalline WC particles; 0.05 to 0.5 weight percent niobium metal powder; and 0.05 to 1.0 weight percent molybdenum metal powders.
Claim 3
Dependent Claim
48 words
A mixture of hardfacing powders for feeding to a hardfacing weld pool, comprising: macrocrystalline WC; and niobium metal powder in at least a small, but effective, amount to substantially submerge said macrocrystalline tungsten carbide in the hardfacing weld pool and without significant cracking of the hardfacing weld pool.
Claim 4
Dependent Claim
48 words
A mixture of hardfacing powders for feeding to a hardfacing weld pool, comprising: macrocrystalline WC; and niobium metal powder in at least a small, but effective, amount to substantially submerge said macrocrystalline tungsten carbide in the hardfacing weld pool and without significant cracking of the hardfacing weld pool.
Claim 5
Dependent Claim
25 words
A mixture of hardfacing powders according to claims 1 or 2 wherein said macrocrystalline WC comprises particles having a size between 10 and 200 mesh.
Claim 6
Dependent Claim
28 words
A mixture of hardfacing powders consisting essentially of: tungsten carbide particles; 0.05 to 0.5 weight percent niobium metal powder; and 0.05 to 1.0 weight percent molybdenum metal powder.
Claim 7
Dependent Claim
28 words
A mixture of hardfacing powders consisting essentially of: tungsten carbide particles; 0.05 to 0.5 weight percent niobium metal powder; and 0.05 to 1.0 weight percent molybdenum metal powder.
Claim 8
Dependent Claim
35 words
A mixture of hardfacing powders according to claim 4 wherein said tungsten carbide particles are selected from the group consisting of macrocrystalline WC, cast tungsten carbide, cemented tungsten carbide, and their mixtures with each other.
Claim 9
Dependent Claim
16 words
A mixture of hardfacing powders according to claim 5 wherein said tungsten carbide is macrocrystalline WC.
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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) | 1986-11-07 | 1987-05-09 | 1987-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-07 | 1991-05-09 | 1991-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-07 | 1995-05-09 | 1995-11-08 | $7700.00 | Window Closed / Lapsed |