Cold forging is of high dimensional accuracy, good surface roughness, good operating conditions and high production efficiency. Therefore cold forging can replace machining sometimes. Cold forging can build metal reinforcement, improve the strength of parts. So it is applicable to aluminum and plastic parts alloy, copper and alloys, low carbon steel, medium carbon steel, low alloy steel which the deformation resistance is small under room temperature. But when cold plasticity, metal deformation resistance is big, with poor plasticity, and contains accumulation of residual internal stress, needs to be continue deformation after intermediate annealing.
2) Warm forging: forging processed around the re-crystallization temperature.
Warm forging process is to obtain precision forgings. The warm forging can improve the precision quality of forgings, at the same time, do not have the forming force as same as cold forging. Warm forging is applicable to complicated shape of small medium carbon steel precision die forgings.
3) Hot forging: deformation temperature above the re-crystallization temperature.