Fracture failure analysis of AISI 304L stainless steel shaft

• Failure analysis of an agitator shaft was presented.
• Finite element analysis was chosen to evaluate stress analysis during operation in transient and steady state conditions.
• Microscopic fractography used by Bates–Clark equation to obtained stress intensity factor.

Fracture failure analysis of an agitator shaft in a large vessel is investigated in the present work. This analysis methodology focused on fracture surface examination and finite element method (FEM) simulation using Abaqus software for stress analysis. The results show that the steel shaft failed due to inadequate fillet radius size and more importantly marking defects originated during machining on the shaft. In addition, after visual investigation of the fracture surface, it is concluded that fracture occurred due to torsional–bending fatigue during operation.