The forging process generally consists of the following processes: blanking, heating, forming, cooling after forging, pickling heat treatment after forging. In the process of forging, if the process is improper, a series of forging defects may be produced.

The heating process includes charging temperature, heating temperature, heating speed, holding time, furnace gas composition, etc. If the heating is improper, for example, the heating temperature is too high the heating time is too long, it will cause decarburization, overheating, over burning other defects.

If the heating speed is too fast the holding time is too short, the temperature distribution will be uniform, resulting in thermal stress cracking of the forging blank.

Forging forming process includes deformation mode, deformation degree, deformation temperature, deformation speed, stress state, conditions of tools dies, lubrication conditions, etc. if the forming process is proper, coarse grains, uneven grains, various cracks, folding, flow through, eddy current as cast structure residue may be caused.

During the cooling process after forging, if the process is improper, it may cause cooling cracks, white spots, network carbides, etc.