What is auotforettaged?

Question

This term used for mechanical parts

Answer 1

Autofrettage:

metal fabrication technique used to strengthen pressure vessels and gun barrels

Answer 2

Autofrettage is used to introduce advantageous residual stresses intopressure vessels and to enhance their fatigue lifetimes. The Bauschinger effect serves to reduce the yield strength in compression as a result of prior tensile plastic overload and can produce lower compressive residual hoop stresses near the bore than are predicted by ideal' autofrettage solutions (elastic/perfectly plastic without Bauschinger effect). A procedure encompasses representation of elastic-plastic uniaxial loading material behavior and of reverse-loading material behavior as a function of plastic strain during loading. Such data are then combined with some yield criterion to accurately predict elastic-plastic residual stress fields within an autofrettaged thick cylinder. Pressure for subsequent re-yielding of the tube iscalculated. The numerical procedure is further used to determine residual stressfields after removal of material from inside diameter (ID) and/or outside diameter (OD), including the effects of any further plasticity.