Material and Heat Treatment of Gear

Selection of gear materials. Materials should be selected according to its working conditions, which has a direct impact on gear machining performance and service life. In general, for the force transmission gear of low speed and heavy load, the surface is easy out of shape and easily broken. So the gear’s material should be of high intensity and hardness, for example 18CrMnTi. For the power transmission gear with high linear speed, its surface can produce pitting. So the surface of gear should have enough hardness. It is recommended to use 38CrMoAlA nitriding steel. The force of gear, should be used in ductile materials, such as low carbon alloy steel 18CrMnTi. Non force transmission gear can be used without hardened steel, cast iron, fabric, nylon and other non-metallic materials. General purpose gear is made of medium carbon steel and low carbon steel such as 20Cr, 40Cr, 20CrMnTi etc.

Heat treatment of gear machining. There are two kinds of heat treatment process according to different purposes. (a) Blank heat treatment before and after the gear blank processing arrangement of pre heat treatment, normalizing and tempering. Its main purpose is to eliminate the residual forging and machining caused by stress, improving material cutting performance and the comprehensive mechanical properties. 

(b) After the treatment of the tooth surface heat treatment, carburizing, quenching, high frequency quenching, carbonitriding and nitriding treatment processes are often carried out in order to improve the hardness and wear resistance of the gear surface.

Zhejiang Hongye Agricultural Equipment Science and Technology LTD, Rotary Mower Gearbox & Agricultural Gearbox Manufacturer in China offers useful information for you.