US4454740A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for simultaneous peening and smoothing
Assignee: RTX Corp
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Filing: 1981-09-10
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Granted: 1984-06-19
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Expires: 2001-09-10
Abstract
Abstract A method for simultaneously shot peening and smoothing includes use of relatively large, smooth, hard, spherical steel shot having a substantially uniform diameter in the range 1-2.5 mm. Titanium workpieces are provided in one step with a compressive stress layer of the order of 0.13 mm and a surface finish of better than 15×10 -6 inch AA, compared to conventional peened finishes of the order of 40×10 -6 inch AA. Surface finish and peening intensity are inter-related and dependent on shot diameter, mass, velocity, and energy within relatively small limits. The shot diameter is uniform within ±0.05 mm; the shot impact velocity is uniform within ±4 percent or less, in the range 1.4-12 m/s.
Inventors
- 👤 James W. Neal
- 👤 Joseph F. Loersch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:20
CPC Classifications
C; C21; C21D; C21D7/00; C21D7/02; C21D7/04; C21D7/06; C22; C22F; C22F1/00; C23; C23C; C23C24/00; C23C24/02; C23C24/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
79 words
The method of surface treating a workpiece, to provide residual compressive stresses corresponding to a peening intensity of at least 0.1 mm N and a surface finish smoother than 40 microinch AA, characterized by impacting the workpiece surface with spherical shot particles, the shot particles being infrangible, having a hardness greater than the workpiece, a surface finish better than 30 microinch AA, and diameters lying in the range 1-2.5 mm which are substantially uniform to within at least ±5%.
Claim 2
Independent Claim
79 words
The method of surface treating a workpiece, to provide residual compressive stresses corresponding to a peening intensity of at least 0.1 mm N and a surface finish smoother than 40 microinch AA, characterized by impacting the workpiece surface with spherical shot particles, the shot particles being infrangible, having a hardness greater than the workpiece, a surface finish better than 30 microinch AA, and diameters lying in the range 1-2.5 mm which are substantially uniform to within at least ±5%.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein the shot particle masses are uniform within ±16%.
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein the shot particles have a velocity in the range 1.4-12 meters per second, uniform within ±4%.
Claim 5
Dependent Claim
14 words
The method of claim 3 wherein the velocity is in the range 2.5-7.8 m/sec.
Claim 6
Dependent Claim
16 words
The method of claim 1 wherein the shot particle diameters are in the range 1.5-2 mm.
Claim 7
Independent Claim
28 words
The method of claims 1, 2, 3, 4 or 5 wherein the peening intensity is in the range of 0.1-1.0 mm N as measured by the Almen method.
Claim 8
Dependent Claim
21 words
The method of claim 6 wherein the shot particles have unit energies in the range 0.2×10 -4 to 12×10 -4 J.
Claim 9
Dependent Claim
18 words
The methods of claim 6 wherein the shot particles are accelerated by gravity over a ,distance 0.3-6 m.
Claim 10
Dependent Claim
56 words
The method of claim 5 further characterized by the shot mass and velocity being selected to provide a peening intensity in the range 0.20-0.50 mm N and a surface finish of at least 15 microinch AA in a titanium alloy workpiece, the mean shot unit energy lying in the range 0.6×10 -4 to 3×10 -4 J.
Claim 11
Dependent Claim
13 words
The method of claim 9 further characterized by the shot being hardened steel.
Claim 12
Dependent Claim
38 words
The method of claim 1 further characterized by finishing the workpiece to a surface finish of less than 40 microinch AA prior to peening, to provide a surface finish of at least about 15 microinch AA after peening.
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) | 1987-06-19 | 1987-12-19 | 1988-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-19 | 1991-12-19 | 1992-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-19 | 1995-12-19 | 1996-06-19 | $7700.00 | Window Closed / Lapsed |