Process
The forging process involves heating the metal, then pressing or hammering it into shape. It starts by cutting a metal billet to the needed size. The billet is then heated in a furnace until it becomes very hot. Once it is hot, the billet is placed between two dies. A press or hammer is then used to give the metal the desired shape.
Once the part is shaped, it is allowed to cool down. Some parts may be trimmed or machined after forging. Heat treatment is often used to adjust hardness.
Classification
Forging can be classified based on two primary factors, which are temperature and the type of die used:
Based on Temperature
Hot Forging: This is when the process is done above the metal’s recrystallization point.
Cold Forging: If the process is done at room temperature, it is considered cold forging.
Warm Forging: This process is done at intermediate temperatures between hot and cold forging.
Based on the Die Used
Open-Die Forging: Here, the metal is upset between flat dies with no full enclosure.
Closed-Die Forging: In this process, the metal fills a shaped die cavity.
