Forging : Hot Forging
Forging is a metalworking process in which an impact device is used to deliver compressive force to areas of the metal in order to shape it. Forging was originally done manually with a hammer and anvil, however industrial forging machines now use hydraulics, compressed air, or other methods to drive mechanical hammers, or presses, into the surface. Hot forging is the term applied when the material is heated to a temperature that exceeds the recrystallization temperature of the metal. A common guideline for this lower limit is 0.6 times the metal's melt temperature. Hot forging helps to prevent the work hardening resulting from the cold forging process.