FORGING • Forging is the working into a useful shape by hammering or pressing. • A wide variety of forging machinery. • Small to large components, such as a bolt to a turbine rotor or an entire airplane wing. • Most forging operations are carried out hot.
Two major classes of equipment: a) The forging hammer or drop hammer delivers rapid impact blows to the surface of the metal. b) The forging press subject the metal to a slowspeed compressive force. Two broad categories of forging processes: i) Open-die forging ii) Closed-die forging
• Open-die forging is carried out between flat dies or dies of very simple shape. • Mostly for large objects or when the number of parts produced is small. • Often open-die forging is used to preform the workpiece for closed-die forging. In closed-die forging the work-piece is deformed between two die halves which carry the impression of the desired final shape. The work-piece is deformed under high pressure in a closed cavity, and thus precision forgings with close dimensional tolerances can be produced
Forging operations: (a,b) Edging; (c) Fullering; (d) Drawing; (e) Swaging; (f) Piercing; (g) Punching.
Schematic drawings of forging equipment.