US3770512A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for surface hardening steel and cemented carbides
Assignee: Individual
•
Filing: 1971-07-26
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Granted: 1973-11-06
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Expires: 1991-07-26
Abstract
Abstract A method of surface hardening steel and cemented carbides, wherein the material to be treated is at a temperature exceeding approximately 570* C and while extensively excluding oxygen is brought into contact with a mixture containing approximately 5 70 parts by weight borium carbide, 1 - 60 parts by weight anhydrous aluminum oxide, trace amounts up to 6 parts by weight NaBF4, and trace amounts up to 10 parts by weight sodium fluoride.
Inventors
- 👤 A Bopp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:45
CPC Classifications
C; C23; C23C; C23C30/00; C23C30/005; C23C12/00; C23C12/02; C23C8/00; C23C8/60; C23C8/62; C23C8/68; C23C8/70
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
14 words
The method as defined in claim 1, further including the step of adding tetrafluoromethane.
Claim 2
Dependent Claim
19 words
The method as defined in claim 1, further including the step of adding to the mixture basic magnesium carbonate.
Claim 3
Dependent Claim
17 words
The method as defined in claim 1, further including the step of adding to the mixture carbon.
Claim 4
Dependent Claim
43 words
The method as defined in claim 1, further including the step of adding to the mixture a member selected from the grouP consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, B, or the oxides, carbides, borides, nitrides or silicides thereof.
Claim 5
Dependent Claim
43 words
The method as defined in claim 1, wherein the components of the mixture are present in a powdery form with a granulation size of approximately 180 to 320 mesh with said surface of said material to be hardened being compacted in said powder.
Claim 6
Dependent Claim
19 words
The method as defined in claim 1, further including the step of adding a liquid carrier to the mixture.
Claim 7
Dependent Claim
15 words
The method as defined in claim 1, of adding dibutyl phthalate as a liquid carrier.
Claim 8
Dependent Claim
47 words
The method as defined in claim 1, wherein the mixture provided is a powder having the following composition: B4C 50 parts by weight Industrial anhydrous aluminum oxide 43 parts by weight Carbon black 2 parts by weight NaBF4 2 parts by weight NaF 3 parts by weight
Claim 9
Dependent Claim
61 words
The method as defined in claim 7, wherein the mixture provided is a liquid form having the following composition: B4C 85 parts by weight Industrial anhydrous aluminum oxide 73 parts by weight Carbon black 3.5 parts by weight NaBF4 3.5 parts by weight NaF 5 parts by weight Basic magnesium carbonate 25 parts by weight Dibutyl phthalate 365 parts by weight
Claim 10
Dependent Claim
23 words
The method as defined in claim 1, wherein the mixture contains 1 to 10 ppm NaBF4 and 1 to 10 ppm sodium fluoride.
Claim 11
Dependent Claim
21 words
The method as defined in claim 1, including the step of carrying out treatment at a temperature up to 1,150* C.
Claim 12
Dependent Claim
20 words
The method as defined in claim 1, including the step of carrying out treatment at a temperature around 850* C.
Claim 13
Dependent Claim
27 words
The method as defined in claim 1, including the step of carrying out treatment at a temperature in the range of about 750* C to 900* C.
Claim 14
Dependent Claim
24 words
The method as defined in claim 1, wherein the initial step consists of embedding the material undergoing treatment in the mixture of powdery form.
Claim 15
Dependent Claim
28 words
The method as defined in claim 1 wherein the initial step consists of applying a dispersion of said mixture in a liquid carrier to the material undergoing treatment.
Claim 16
Dependent Claim
28 words
The method as defined in claim 16, wherein the step of applying the dispersion in the liquid carrier to the material undergoing treatment is by spraying such thereon.
Claim 17
Dependent Claim
31 words
The method as defined in claim 17, wherein the step of applying the dispersion which is in a liquid carrier to the material undergoing treatment is by immersing such material therein.
Claim 18
Dependent Claim
28 words
The method as defined in claim 16, wherein the step of applying the dispersion in a liquid carrier to the material undergoing treatment is by wiping such thereon.
Claim 19
Dependent Claim
22 words
The method as defined in claim 1, including the step of providing for the exclusion of air for carrying out the treatment.
Claim 20
Dependent Claim
59 words
A composition of matter for use in surface hardening materials, especially steel and cemented carbides, said composition of matter consisting essentially of a mixture containing approximately 5 to 70% by weight boron carbide, 1 to 60% by weight anhydrous aluminum oxide, trace amounts up to 6% by weight NaBF4, and trace amounts up to 10% by weight sodium fluoride.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |