Inspection results of gear heat treatment items

The influence of pre heat treatment on gear heat treatment deformation, and the results are analyzed according to the scheme and implementation.

The test results of isothermal annealing hardness and normalizing hardness of 9t first speed gear blank are shown in Table 1;

Pre heat treatment methodHardness of gear blank (HB)Sheet P + F levelBanded organization level
Isothermal annealing160-18011
Normalizing190-24032

The microstructure of gear blank after isothermal annealing is shown in Figure 1;

See Table 2 for gear carburizing results;

NameSurface hardnessCore hardnessCMA’FHardened layer depth HV550Conclusion
One speed gearHRC61HRC3512211.10mmQualified
spacer