Device and method for the autofrettage of a workpiece

A method of autofrettage comprising:

• positioning a workpiece between a first securing means and a second securing means;
• applying fluid to an internal volume of the workpiece formed between the first securing means and the second securing means;
• driving a die into the internal volume through an opening in the first securing means;
• and
• by movement of the die, generating a fluid pressure in the internal volume and mechanically autofrettaging the workpiece,
• wherein a pressure-induced widening of the workpiece that results from the movement of the die depends on a size of the die, wherein the pressure-induced widening of the workpiece is independent of a rate at which the die is driven.

An autofrettage tool apparatus for autofrettage of a workpiece, the autofrettage tool apparatus comprising:

• a first securing means that includes an opening;
• a second securing means, wherein an internal volume of the workpiece is positionable between the first securing means and the second securing means, wherein the internal volume of the workpiece is configured to receive fluid;
• and
• a die configured for mechanical autofrettage of the workpiece, wherein the die is configured to be positioned in the opening of the first securing means,
• wherein the autofrettage tool apparatus is configured for hydromechanical autofrettage of the workpiece by way of fluid and the die,
• wherein at least one of:
• a head is detachably fastened on the die or is mounted on an end side in front of the die;
• or
• a head of the die comprises a front-side chamfer and a rear-side chamfer, wherein between the front-side chamfer and the rear-side chamfer a lateral surface that is cylindrical or becomes conically wider toward the rear-side chamfer is formed.