Patent ID: 8408033
Filing Date: 2013-04-02
Classification: B23P,C21D

Abstract:
1. An autofrettage process, wherein interior regions of a workpiece are permanently plastically deformed under high pressure, whereas exterior regions of the workpiece are only elastically deformed, the process comprising the steps of: placing a workpiece having an interior space and a displacement piston opening in an autofrettage apparatus, filling the interior space of the workpiece from below with a fluid through a pre-fill opening, closing the pre-fill opening with a closure piston, venting air from a region of the displacement piston opening, until the fluid flows out of the displacement piston opening of the workpiece disposed at a top of the workpiece, sealing the interior space of the workpiece by pressing a sealing sleeve surrounding the closure piston against a flange face of the workpiece so as to be pressure-tight, and advancing a displacement piston through the displacement piston opening into the interior space of the workpiece to reduce a volume available to the fluid in the interior space.