The main methods of forging are free forging and die forging.
Free forging is a simple and flexible basic forming method of metal plastic processing. It uses the upper and lower anvil blocks of forging equipment and some simple general tools to make the blank produce plastic deformation under the action of pressure. Free forging can be divided into manual forging and machine forging. With the rapid development of machine manufacturing industry, machine forging is mainly used in production. According to different types of forging equipment, machine forging can be divided into forging hammer free forging and hydraulic press free forging. The former is used to forge small and medium-sized forgings, while the latter is mainly used to forge large forgings.
Because the tools used in free forging are simple, versatile and flexible, it is suitable for the production of single piece and small batch forgings. The free forging is formed by the gradual deformation of the blank, and the tool is only in contact with the blank, so the required equipment power is much smaller than that of die forging, so the free forging is also suitable for forging large forgings. For example, the 10000 ton die forging hydraulic press can only forge forgings weighing hundreds of kilograms, while the 10000 ton free forging hydraulic press can forge large forgings weighing more than 100 tons. It can be seen that for the forging of large forgings, only free forging technology can be adopted. However, free forging depends on the operation of workers to control the shape and size of forgings, so the precision of forgings is poor, the forging productivity is low and the labor intensity is high. In view of the above shortcomings, in recent years, free forging production is constantly improving and developing in improving forging accuracy and realizing mechanization.
Die forging is the main process of forging. The equipment used mainly includes die forging hammer, anvil free hammer, crank press, screw press and high-speed hammer. Die forging has high productivity, stable forging size and high material utilization, so it is widely used in batch and mass production of small and medium-sized forgings. In automobile, tractor, aircraft, power machinery and other industries, it is estimated that the number of die forgings is large, accounting for about 90% of the total weight of forgings in these industries.
In addition to the basic methods of free forging and various die forging, there are also some other special forming methods, such as electric upsetting, cold extrusion, rotary forging, roll forging, swing rolling, multi hammer precision forging, magnetic forging, superplastic forming, hydrostatic forming and suspension forging, which have developed rapidly at home and abroad in the past 20 years. This kind of special forging technology will strongly promote the rapid development of material processing industry.
