DIECKERS GMBH & CO. KG

Autofrettage

Autofrettage is a process used to increase the load-bearing capacity of components subjected to internal pressure that can significantly increase their service life. The effect of autofrettage is based on the deliberate inducing of residual compressive stresses, which counteract the tensile stresses in the application.
By loading the component just once with a very high internal pressure that is significantly higher than the operating pressure required later, various deformation zones occur (see figure). When this pressure is relieved, the elastically deformed area returns to its original state and presses against the plastically deformed area on the inside. This results in the desired residual stresses.

Possible applications:

• High-pressure lines and fittings
• Components for common rail diesel injection
• Valve and manifold blocks