Patent ID: 8056279
Filing Date: 2011-11-15
Classification: B23P,C21D,Y10T

Abstract:
1. A process for autofrettaging a gun barrel, the process comprising: providing a gun barrel having an outer surface, an inner surface, an inner diameter and an interior volume; providing an elongated elastomer or plastic expander dimensioned and shaped to be inserted within the inner diameter of the gun barrel; placing the elastomer or plastic expander within the gun barrel; placing end caps at least partially within the gun barrel so as to bound the elastomer or plastic expander within the gun barrel; providing a hydraulic compression system having at least one hydraulic cylinder; applying an axial compressive force onto the elastomer or plastic expander using the at least one hydraulic cylinder of the hydraulic compression system, the axial compressive force inducing predominantly elastic strain on the outer surface of the gun barrel and elastic plus plastic strain on the inner surface of the gun barrel such that a residual compressive stress is present at the inner surface of the gun barrel when the applied axial compressive force is removed from the opposite ends of the elastomer or plastic expander.