Patent US4118224A successfully refreshed from Google Patents.
US4118224A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nickel-chromium heating element alloy having improved operating life
Assignee: Wilbur B Driver Co
•
Filing: 1976-12-06
•
Granted: 1978-10-03
•
Expires: 1996-12-06
Abstract
Abstract The addition of about 0.33 weight percent of hafnium to a nickel-chromium heating element alloy having a nominal composition of 20 weight percent chromium, 1.4 weight percent silicon, balance essentially nickel, results in an improved operating life of the alloy.
Inventors
- 👤 Teh Po Wang
- 👤 Carrol Dean Starr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:50
CPC Classifications
C; C22; C22C; C22C19/00; C22C19/03; C22C19/05; C22C19/058; H; H05; H05B; H05B3/00; H05B3/10; H05B3/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
60 words
A nickel-chromium heating element alloy consisting essentially of a base composition in weight percent within the range of: 18 to 22 percent chromium, 1.0 to 1.6 weight percent silicon, balance essentially nickel, characterized in that the alloy contains from about 0.1 to 0.75 weight percent hafnium, whereby the operating life of the alloy as a resistance heating element is improved.
Claim 2
Dependent Claim
60 words
A nickel-chromium heating element alloy consisting essentially of a base composition in weight percent within the range of: 18 to 22 percent chromium, 1.0 to 1.6 weight percent silicon, balance essentially nickel, characterized in that the alloy contains from about 0.1 to 0.75 weight percent hafnium, whereby the operating life of the alloy as a resistance heating element is improved.
Claim 3
Dependent Claim
19 words
The alloy of claim 1 wherein hafnium is present in the amount from about 0.1 to 0.5 weight percent.
Claim 4
Dependent Claim
35 words
The alloy of claim 1 additionally containing up to 0.10 weight percent each of one or more elements selected from the group of deoxidizers consisting of Ca, C, Mm, Zr, Mg, Al, B and Ti.
Claim 5
Dependent Claim
28 words
The alloy of claim 1 consisting essentially of in weight percent: Cr: 20 Si: 1.4 Hf: 0.25, up to 0.5 total of Ca, Al and B, balance Ni.
Claim 6
Dependent Claim
12 words
A resistance heating element consisting essentially of the alloy of claim 1.
References Cited (Backward Citations)
US3627511A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-02 | 1982-04-03 | 1982-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-02 | 1986-04-03 | 1986-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-02 | 1990-04-03 | 1990-10-03 | $7700.00 | Window Closed / Lapsed |