In this paper

macro and micro analysis are made on the GH4169 M60 fracture stud which is fixed bracket.Visual inspection of fracture surface shows that the feature of crack is brittle fracture

and the fracture finally occurs at the joint of the thread and nut. Penetration test finds that five continuous cracks inside the stud parallel to the thread

and SEM finds that the cracks between the threads at the fracture part show irregular sharp edges

and the fracture surface presents typical quasi-cleavage fracture characteristics. By EDS

the presence of carbide phase in the fracture is verified and the effect of carbide on brittle fracture is analyzed. The results show that the thread tends to cause stress concentration

thus enhancing the sensitivity of the stud to defects and leading to brittle fracture. Comparing the fracture surface micro-morphology of the threadless specimen

it is found that the fracture has nothing to do with the material itself

and the broken carbides are the typical characteristics of Inconel GH4169 ductile-brittle mixed fracture.