US4485148A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chromium boron surfaced nickel-iron base alloys
Assignee: RTX Corp
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Filing: 1983-07-08
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Granted: 1984-11-27
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Expires: 2003-07-08
Abstract
Abstract Chromium boron diffusion coatings on nickel iron alloys uniquely provide them with improvement in high cycle fatigue strength (up to 30%) and erosion resistance (up to 15 times), compared to uncoated alloy. The diffused chromium layer extends in two essential concentration zones to a total depth of about 40×10 -6 m, while the succeeding boron layer is limited to 50-90% of the depth of the richest Cr layer nearest the surface. Both coatings are applied using conventional pack diffusion processes.
Inventors
- 👤 James M. Rashid
- 👤 Leonard A. Friedrich
- 👤 Melvin Freling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:32
CPC Classifications
C; C23; C23C; C23C12/00; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12458; Y10T428/12493; Y10T428/12771; Y10T428/12778; Y10T428/12806; Y10T428/12826; Y10T428/12847; Y10T428/12854
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
92 words
A wear resistant article comprised of a nicle-iron base substrate containing by weight percent 25-45 Ni, 30-50 Fe, at least 10 Cr, an other elements, wherein Co may be substituted for a portion of the Ni, having a diffusion coating of chromium and boron, the coating comprising a chromium layer having a first super-enriched Cr portion near the article surface and a second enriched Cr portion adjacent thereto, the second portion having a lesser concentration of chromium than the first portion, wherein boron is detectable only in the first chromium layer portion.
Claim 2
Dependent Claim
92 words
A wear resistant article comprised of a nicle-iron base substrate containing by weight percent 25-45 Ni, 30-50 Fe, at least 10 Cr, an other elements, wherein Co may be substituted for a portion of the Ni, having a diffusion coating of chromium and boron, the coating comprising a chromium layer having a first super-enriched Cr portion near the article surface and a second enriched Cr portion adjacent thereto, the second portion having a lesser concentration of chromium than the first portion, wherein boron is detectable only in the first chromium layer portion.
Claim 3
Dependent Claim
44 words
The article of claim 1 having a resistance to particulate erosion which is at least five times better than the erosion resistance of an uncoated article and having a fatigue resistance which is at least equal to the fatigue resistance of an uncoated article.
Claim 4
Dependent Claim
23 words
The articel of claim: 1 wherein the boron is present to 50-90 percent of the depth of the first portion of the layer.
Claim 5
Dependent Claim
53 words
A wear resistant article comprised of a nickel iron base substrate consisting essentially by weight percent of 11-14 Cr, 40-45 Ni, 5-6.5 Mo, 2.6-3.1 Ti, 0.01-0.02 B, 0.02-0.08 C., balance Fe, wherein Co may be substituted for a portion of the Ni, having on its surface a diffusion coating of chromium and boron.
Claim 6
Dependent Claim
53 words
A wear resistant article comprised of a nickel iron base substrate consisting essentially by weight percent of 11-14 Cr, 40-45 Ni, 5-6.5 Mo, 2.6-3.1 Ti, 0.01-0.02 B, 0.02-0.08 C., balance Fe, wherein Co may be substituted for a portion of the Ni, having on its surface a diffusion coating of chromium and boron.
Claim 7
Dependent Claim
26 words
The article of claim 4 wherein the material has a high cycle fatigue strength at 10 7 cycles of at least about 340 MPa (˜50 ksi).
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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) | 1987-11-27 | 1988-05-28 | 1988-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-27 | 1992-05-28 | 1992-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-27 | 1996-05-28 | 1996-11-27 | $7700.00 | Window Closed / Lapsed |