How is the surface hardening effect of gears? What is the application?

  This paper mainly introduces the effect of gear surface hardening and the application of gear surface hardening technology.

A. The tooth root is not hardened

Process method: rotary heating quenching method.

Strengthening effect: the wear resistance of the tooth surface is improved; The bending fatigue strength does not have much effect and the allowable bending stress is lower than the tempered level of the steel.

m is the gear module (mm)

B. The root of the gear is hardened

Process method: rotary heating quenching method.

Strengthening effect: the wear resistance of tooth surface and the fatigue strength of tooth root was improved. The allowable bending stress is 30%~50% higher than that of the tempered state. Partial replacement of carburized gear.

C. The root of the gear is hardened

Process method: single tooth continuous heating quenching method.

Strengthening effect: the wear resistance of the tooth surface is improved; The bending fatigue strength is affected to a certain extent (generally the hardening layer ends at a distance of 2~3mm from the tooth root); The allowable bending stress is lower than the tempered level of the steel.

D. The root of the gear is hardened

Process method: continuous quenching along the tooth groove.

Strengthening effect: the wear resistance of tooth surface and the fatigue strength of tooth root was improved. The allowable bending stress is 30%~50% higher than that of the tempered state. Partial replacement of carburized gear.

The typical processing flow of surface quenching gear: blank → forging billet normalizing (or annealing) → mechanical rough machining → tempering → mechanical semi-finishing (billet making) and gear making → surface quenching → low temperature tempering → mechanical finishing → finished product.