Application of precision die forging technology in bevel gear machining

The general plastic precision forming process is precision die forging, which is a less cutting process gradually developed from general die forging. According to the temperature of metal forming, it can be divided into cold forging, hot forging and warm forging:

(1) Cold forging is forging at room temperature, which can obtain high surface quality and good dimensional accuracy. However, its forming ability is limited, deformation resistance is large and die life is low, so how to improve die life is a main obstacle to the research of cold forging technology.

(2) Hot forging is applicable to almost all steel grades and can produce parts of various shapes. However, strong oxidation reaction will occur during hot forging, which will reduce the surface properties of forgings, resulting in large dimensional tolerance and subsequent machining allowance.

(3) Warm forging is a relatively new process method. Its forming temperature is usually between 650-950 ° C, which combines the advantages of hot forging and cold forging. The forgings produced by this method not only have good formability of hot forgings, but also have high-quality machined surface of cold forgings, so it is a promising process method. However, there are many factors to be considered in its process, and the research on process specification is not mature. At the same time, the cost of process design and die development is relatively higher than that of hot forging and cold forging.

The more advanced and widely used gear processing technology at home and abroad is thermal precision die forging, which can improve the strength and bending fatigue performance of gears, reduce heat treatment deformation, improve product accuracy, save materials, reduce man hours and reduce production costs. However, it still has the disadvantages of the above hot forging: there are many processes, high energy consumption, the heating temperature needs to be strictly controlled, the oxide scale on the forging can not be too much, and it needs to be removed in time. It is best to use non oxidation heating.