Mehmet ALADAĞ, Ömer EYERCİOĞLU, Gülağa TAŞ

THE EFFECTS OF PUNCH SPEED ON THE FORGING LOAD OF HOT PRECISION BEVEL GEAR FORGING

The mass production bevel gears is mainly realized by precision forging process. The process can be carried out cold, warm or hot conditions by using various forging presses (hydraulic or mechanical presses and HERF machines). The process cycle time is changing with the type of forging press (i.e. the speed of punch). During hot forging, the hot billet is in contact with the relatively colder die and heat is transferred to the environment. Therefore, the billet temperature is changing during deformation and the processing time is an effective parameter of the temperature distribution of the billet. The flow stress of the material and the forging load are increasing with reducing billet temperature. In this study, the effect of punch speed on the forging load were investigated by the finite element method. To simulate different forging presses, various punch speeds were chosen as 0.001 m/s, 0.01 m/s, 0.1 m/s, 1 m/s. and 10 m/s. In accordance with these punch speeds, the temperature distribution of the billet and the forging loads were determined. The results show that the temperature drop of the billet and the forging load are decreasing with the increasing punch speed. So that forging with HERF machines is advantageous than the hydraulic and mechanical presses in the precision hot forging process of bevel gears.

Keywords:

Bevel gear forging forging, finite element method, heat treatment,

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