Abstract: A certain 30CrMnSiA component was stored in a warehouse in Southwest China.During the process of being taken out from the warehouse,it suddenly fractured.In order to analyze the failure of this fracture,various methods such as macroscopic observation,fracture surface morphology analysis,chemical composition analysis,and microscopic structure analysis were employed.The results indicate that the corrosion gap width of the component is approximately 0.089mm,with a large area of dark brown deposits adhering to the gap surface.Energy-dispersive X-ray spectroscopy(EDS)reveals the presence of corrosive media Cl and F near the fracture surface,and X-ray diffraction(XRD)phase analysis indicates the presence of NaCl and Fe3O4.The analysis suggests that the failure is attributed to the coupled effect of gap corrosion and stress.