
1. Heating: Pre-forged metal starts with metal blocks
called "ingots," which come in a variety of shapes and sizes depending
on the part or component to be produced. These ingots are heated to a
near molten state where the metal still retains its shape but can be
altered easily with force.
2. Preforming: In order to form a piece of the ingot to
be pressed between the closed dies, the heated ingot is edged and
blocked with a press or hammer. Edging is done to increase the working
cross section and blocking is implemented to refine the shape for finish
forging.
3. Finish Forging: To complete the shape, the preformed
metal is forced into an impression between two dies; this is where the
metal takes on the general shape of the end product. Simple items may
only need one press, but more complicated items may require multiple
strokes at different pressures or even different dies to design the
final product.
4. Cooling: By coordinating the cooling of the metal,
forgers can increase the strength of the final product by deforming and
optimizing the grain flow within the metal. A aspect of impression die
forging is the "flash," which is the excess metal that flows outside of
the dies. The flash cools and hardens rapidly causing it to be stronger
than the metal in the dies. This forces the metal in the dies to
completely fill any cavities.
5. Finishing: Once a forged product has gone through
the pressing process, trimming and other surface treatment operations
are performed in order to improve the dimensional accuracy of the forged
product. Surface treatment can be completed to enhance corrosion
resistance and improve the appearance of the finished forged product.