The essence of metal forging processing is to make use of the plasticity of metal and its ability to produce plastic deformation, with the help of tools or molds, under the action of external impact force or pressure, so that the blank forming, has a certain shape, size, internal organization and mechanical properties to meet the requirements of the mechanical parts or blank processing method.

Compared with metal casting, welding and cutting processing methods, forging processing has the following characteristics.

1. The organization and performance of forgings are improved. Metal after forging processing, its internal organization has significant changes, such as steelmaking production of ingot, its internal often exists loose, coarse grain, uneven organization, composition segregation and other defects, after forging and other pressure processing in the organization of loose forging, internal dense, break coarse dendrites, refine grains, improve segregation. The forgings formed by the blank forging have good shape and size stability, reasonable fiber structure, fine structure, improve the distribution of the second phase, the plasticity, impact toughness, fatigue properties of the forgings have been greatly improved, and the performance change range between the forgings is small.

2. High utilization rate of materials. Forging processing is the use of metal in the plastic state through the volume transfer to achieve forming, obtain a certain shape and size of the forging, no cutting, only a small amount of process waste, high utilization rate of materials.

3. High dimensional accuracy. The workpiece obtained by metal forging processing can achieve high dimensional accuracy, and the machining allowance of forging is small. Many forging forming methods have reached the requirement of little or no cutting. For example, precision forging bevel gear, the precision of its tooth shape part can be directly used without cutting, precision forging blade complex surface can reach the precision of grinding.

4. The forging process is flexible, which can not only produce single pieces, but also mass production, and the productivity is high. For free forging, the forging production can be carried out in small batches or single pieces. For die forging, due to the continuous development of forging processing equipment and the improvement of mechanization and automation degree, die forging production has higher production efficiency, suitable for mass production. Such as in 120000kN hot die forging press forging a car with six turns crankshaft only 40s; The stroke times of high-speed punch in forging process have reached 1500-1800 times /min; Screw forging and processing M5mm on planet thread rolling machine, production efficiency up to 12,000 pieces /min.