According to different production tools, forging technology can be divided into free forging, module forging, grinding ring and special forging.
Free forging: it refers to forging methods that use simple universal tools, or directly apply external force between the upper and lower anvils of forging equipment to the blank, so as to deform the blank and obtain the required geometry and internal quality of the forging.
Die forging: refers to the forging of a metal blank obtained by pressing and deforming in a certain shape of forging die bore. Die forging can be divided into hot die forging, warm forging and cold forging. Warm forging and cold forging are the future development direction of die forging, and also represent the level of forging technology.
Grinding ring: it refers to the ring-shaped parts with different diameters produced by special equipment grinding ring machine and also used to produce wheel-shaped parts such as automobile wheel hub and train wheel.
Special forging: including roll forging, cross wedge rolling, radial forging, liquid forging and other forging methods, which are more suitable for the production of parts with special shapes.
For example, roll forging can be used as an effective preforming process to greatly reduce the subsequent forming pressure; cross wedge rolling can produce steel ball, transmission shaft and other parts; radial forging can produce large-scale barrel, step shaft and other forgings.
According to forging temperature, forging technology can be divided into hot forging, warm forging and cold forging.
The initial recrystallization temperature of steel is about 727 ℃, but 800 ℃ is generally used as the dividing line, and hot forging is used when the temperature is higher than 800 ℃; warm forging or semi-hot forging is used when the temperature is between 300-800 ℃, and cold forging is used when forging at room temperature. The forgings used in most industries are hot forging. Warm forging and cold forging are mainly used in the forging of an automobile, general machinery and other parts. Warm forging and cold forging can effectively save materials.
According to the motion mode of forging die, forging can be divided into rotary forging, rotary forging, roll forging, cross wedge rolling, ring rolling and cross rolling.