Free forging has low productivity and large machining allowance, but the tools are simple and versatile, making it widely used for forging single piece and small batch forgings with relatively simple shapes. Free forging equipment includes air hammers, steam air hammers, and hydraulic presses, which are suitable for the production of small, medium, and large forgings, respectively. Die forging has high productivity, simple operation, and is easy to achieve mechanization and automation. Die forgings have high dimensional accuracy, small machining allowance, and more reasonable fiber structure distribution, which can further improve the service life of the parts
Basic process of free forging: During free forging, the shape of the forging is gradually formed by forging the blank through some basic deformation processes. The basic processes of free forging include upsetting, elongation, punching, bending, and cutting.
Upsetting is the process of forging the original billet along the axial direction to reduce its height and increase its cross-sectional area. This process is commonly used for forging gear blanks and other disc shaped forgings. Upsetting is divided into two types: full upsetting and partial upsetting.
2. Elongation is a forging process that increases the length of the billet and reduces the cross-sectional area. It is usually used to produce shaft type blanks, such as lathe spindles, connecting rods, etc.
3. The forging process of punching through or through holes on the blank using a punch.
4. Bending is a forging process that bends the billet to a certain angle or shape.
5. Twisting is a forging process in which one part of the billet rotates at a certain angle relative to the other.