The Radial Piston Approach to the Explosive Autofrettage of Thickwalled Forging Dies
A new process for obtaining residual compressive hop stresses at the bore of thickwalled forging dies is presented. The process uses explosive energy in a controlled manner to produce plastic flow in the die. High residual stresses are generated as the applied pressures decay. A theoretical model of the process is developed which predicts residual stress and deformation as a function of the material properties and geometry of the system and the characteristics of the explosive. Experimental data is presented and compared with analytical results. The experiments demonstrate the validity of the analysis and the process itself. The application of explosive autofrettage to a specific production forging die is described. The process is compared with existing methods for producing residual stresses in thickwalled cylinders.
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- 1.J. Mote, L. Ching, R. Knight, R. Fay and M. Kaplan. Explosive autofrettage of cannon barrels. Army Materials and Research Centre Report — AMMRC CR 70–25, February 1971.Google Scholar
- 2.ASME steam tables, ASME, New York, 1967.Google Scholar
- 3.G. Sachs and G. Espey. A new method for determination of stress distribution in thinwalled tubing, Metals Tech., 1384, (1941).Google Scholar
- 6.T. Davidson and D. Kendall. The design of pressure vessels for very high pressure operation, Watervliet Arsenal Technical Report WVT — 6917, May 1969.Google Scholar