Abstract：The causes of premature fracture of aturbine blade made of 1Cr13 steel in a certain enterprise were analyzed by using optical metallography and scanning eletron microscope.The results show that the fracture surface morphology at the crack initiation site consists of intergranular fracture and a small amount of cleavage or quasi-cleavage fracture. Considering both the medium condition and stress conditionofthe inspectionblade，it is considered that thepremature fracture of the bladeis causedby stress corrosion.After the stress corrosioncrackisformed，the crack propagates with the manner of super position of both stress corrosion and fatigue.The coarse grain size increases the sensitivity of 1Cr13 steel to stress corrosion，and decreases the fatigue performance of the material.
2019, Vol. 37 
