Planetary Reducer Heat Treatment Method

- Oct 17, 2019-

The planetary reducer is a device that is often selected in mechanical equipment. The choice of a good planetary reducer material is beneficial to improve the bearing capacity and service life of the gear reducer.

For the structural characteristics of precision reducers and the load characteristics of gears, hard-toothed gears should be widely used. There are many ways to obtain heat treatment for hardened gears. Such as surface quenching, integral quenching, carburizing and quenching, nitriding, etc., which should be selected according to the characteristics of the gear reducer.

1.surface quenching

Common surface quenching methods are high frequency quenching (for small size gears) and flame hardening (for large size gears). The hardened layer of surface quenching including the bottom of the root, which works best. The hardness of the tooth surface can reach 45-55HRC.


The use of nitriding ensures that the gears achieve high tooth surface hardness and wear resistance under the conditions of minimum deformation, and the best finishing is not performed after heat treatment, which improves the bearing capacity.

3.carburizing and quenching

The carburized and quenched gear has a relatively large bearing capacity, but a finishing process (grinding) must be used to eliminate the heat treatment deformation to ensure accuracy.

Carburizing and quenching gears are commonly used in alloy steels with a carbon content of 0.2%-0.3% before carburizing. The hardness of the tooth surface is usually in the range of 58-62HRC. If it is lower than 57HRC, the hardness of the hard surface is significantly decreased, and the brittleness is higher than 62HR. increase. The hardness of the carburized and quenched gear is gradually reduced from the gear surface to the deep layer, and the effective carburizing depth is defined as the depth from the surface to a hardness of 5.25 HRC.

The role of carburizing and quenching in the bending fatigue strength of the gear is not only the improvement of the core hardness but also the residual compressive stress of the surface. It reduces the stress in the region of maximum compressive stress, so the root portion cannot be ground during grinding.