Analysis on surface crack of 20CrMnMo carburized heavy-duty gear steel

The reason of cracking on surface of 20CrMnMo carburized heavy-duty gear was analyzed by SEM and optical metalloscope.The failure mechanism was also discussed.The results show that the microstructure of the quenched steel is coarse acicular martensite,which resulted in brittle fracture of the gear with intergranular cracking.