Classification of forging

    

According to different production tools, forging technology can be divided into # free forging, # module forging, # grinding ring, and # special forging.    

    

Free forging: refers to the processing method of forging that uses simple universal tools or directly applies external forces between the upper and lower anvils of the forging equipment to deform the billet and obtain the required geometric shape and internal quality.    

    

Die forging: refers to the deformation of metal billets under pressure in a forging die chamber with a certain shape to obtain forgings. Die forging can be divided into hot die forging, warm forging, and cold forging. Warm forging and cold forging are the future development directions of die forging, and also represent the level of forging technology.    

    

Ring rolling: refers to the production of circular parts with different diameters using a specialized equipment ring rolling machine, which is also used to produce wheel shaped parts such as car wheels and train wheels.    

    

Special forging: including roll forging, cross wedge rolling, radial forging, liquid die forging, and other forging methods, which are more suitable for producing certain special shaped parts. For example, roll forging can serve as an effective pre forming process, significantly reducing the subsequent forming pressure; Cross wedge rolling can produce parts such as steel balls and transmission shafts; Radial forging can produce large forgings such as gun barrels and step shafts.    

    

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 commonly used as the dividing line, and those above 800 ℃ are hot forged; Forging between 300 and 800 ℃ is called warm forging or semi hot forging, and forging at room temperature is called cold forging. Forgings used in most industries are hot forging, while warm and cold forging are mainly used for forging parts such as automobiles and general machinery. Warm and cold forging can effectively save materials.   

    

According to the movement mode of the forging die, forging can be further divided into swing forging, swing rotary forging, roll forging, cross wedge rolling, ring rolling, and oblique rolling.