US4313771A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser hardening of steel work pieces
Assignee: Xerox Corp
•
Filing: 1980-02-29
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Granted: 1982-02-02
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Expires: 2000-02-29
Abstract
Abstract A method of hardening the surface of steel work pieces is disclosed wherein the work piece is first treated with a solution to cause the blackening thereof and subsequently subjected to a laser beam for a time sufficient to raise the surface temperature thereof into the austenitic phase.
Inventors
- 👤 Roberto Lorenzo
- 👤 Frank J. Wolf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:51
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/06; C21D1/09; B; B23; B23K; B23K2103/00; B23K2103/02; B23K2103/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
98 words
A method of heat treating the surface of carbon steel work pieces which comprises blackening the surface of the steel work piece by a blackening composition containing an alkali metal hydroxide, and an alkali metal nitrate or an alkali metal nitrite, so that at least 65% of the light emitted by a CO 2 laser is absorbed thereby, and directing a CO 2 laser beam having a power output ranging from about 450 watts to about 600 watts at the surface of the work piece for a time sufficient to raise the surface temperature into the gamma range.
Claim 2
Independent Claim
98 words
A method of heat treating the surface of carbon steel work pieces which comprises blackening the surface of the steel work piece by a blackening composition containing an alkali metal hydroxide, and an alkali metal nitrate or an alkali metal nitrite, so that at least 65% of the light emitted by a CO 2 laser is absorbed thereby, and directing a CO 2 laser beam having a power output ranging from about 450 watts to about 600 watts at the surface of the work piece for a time sufficient to raise the surface temperature into the gamma range.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein the blackening composition further containing a phenyl thiourea.
Claim 4
Dependent Claim
23 words
The method of claim 2 wherein the steel work piece has carbon content of from about 0.4 to about 1.2 percent by weight.
Claim 5
Dependent Claim
26 words
The method of claim 2 wherein the surface of the work piece is hardened to a depth of from about 0.15 millimeters to about 0.8 millimeters.
Claim 6
Dependent Claim
24 words
The method of claim 4 wherein the surface of the work piece is hardened to a depth of about 0.2 to about 0.3 millimeters.
Claim 7
Dependent Claim
24 words
The method of claim 2 wherein the CO 2 laser beam is caused to impinge upon the work piece normal to the surface thereof.
Claim 8
Dependent Claim
35 words
The method of claim 2 wherein the work piece and the laser beam is moved relatively with respect to each other at the rate of from about 10 to about 25 linear centimeters per minute.
Claim 9
Dependent Claim
35 words
The method of claim 7 wherein the work piece and the laser beam are moved relative with respect to each other at a rate of from about 15 to about 20 linear centimeters per minute.
References Cited (Backward Citations)
US3447974A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-02-01 | 1985-08-03 | 1986-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-01 | 1989-08-03 | 1990-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-01 | 1993-08-03 | 1994-02-02 | $7700.00 | Window Closed / Lapsed |