With the rapid development of the forging industry, the industry has made great contributions to China’s scientific and technological development, economic construction and social progress. Forging technology has a huge market supply and demand in China, and the supply and demand groups in China’s forging market will develop towards diversification. At present, the enterprise competition mainly lies in the competition of cost and efficiency. As the precision forgings save materials and shorten the process than ordinary die forgings, the forging industry is striving to adopt the precision forging process to realize the net forming and precision of forgings.
Precision die forging technology is a kind of pressure machining method with less cutting. The forgings produced by precision die forging process have high dimensional accuracy, up to 4-5 levels of accuracy; The dimensional tolerance is small, only 1/3 of that of ordinary die forgings, and the draft angle is small, generally 0-3 °; The surface quality of forgings is good, and the surface roughness reaches R α= 12.5-1.6 the forged gear tooth surface can be directly used with the forged surface. Generally, precision die forgings can be assembled without machining or only a small amount of subsequent machining. Compared with ordinary forgings and free forgings, the machining amount is reduced by 50%-80% or more, and the material utilization rate is increased by 60%-80%. At the same time, the internal quality of parts processed and produced by precision forging technology is good. If precision forging is used to produce large quantities of medium and small forgings, its economic benefits will be very significant. If the existing forging and processing equipment can meet the process requirements, the precision die forging technology can be used to produce more than 500 pieces in batch.
The gear precision forging technology refers to the gear manufacturing technology that the gear tooth is directly obtained from the return material through precision forging, and the tooth surface can be used without cutting or only a little precision machining. Compared with the traditional cutting process, the gear precision forging process can improve the gear structure and mechanical properties; Improve material utilization and production efficiency, and reduce production costs; Reduce the tooth profile deformation during heat treatment, improve the wear resistance and meshing stability of the teeth, and improve the service life.
In order to meet the gear precision forging process, higher requirements are put forward for the corresponding process and equipment. For example, the oxide skin on the surface of the precision forging and the material should be removed, and the thickness of the decarburization layer should be strictly controlled; High precision forging dies and friction presses are used as precision forging equipment; Strictly control the forging temperature, die temperature, lubrication and other process factors to minimize the dimensional error of forgings caused by temperature fluctuations; Improve the accuracy of blanking volume.