Numerical Analysis of Tensile Behaviour of Stainless Steel 304 Having Stochastically Distributed Pits

During pitting corrosion, pits are initiated due to localized chemical or mechanical damage of the protective oxide film. Pits are the leading cause of the initiation of the crack in many types of failure, especially in fatigue. Stainless steels are preferred in view of corrosion resistance; however, they too undergo varying degrees of corrosion and hence, it is important to study the corrosion response in sea water conditions for the better usability of structures in marine, pipping, and oil and natural gas extraction to avoid catastrophic structural failure. In this study, the stochastic pit coordinates are generated using MATLAB. These coordinates are used to generate the pits on dogbone specimen on all faces according to the ASTM G46-21 by using PYTHON scripting incorporated with the ABAQUS. Five sets and four different conditions pits are generated on a tensile specimen and numerical simulations were performed, each with a unique stochastic pit distribution. The results indicated significant variations in failure patterns, with different models failing at distinct locations and exhibiting various displacement responses. The findings highlight the importance of accounting the pit geometry and distribution. From this study, it is found that the maximum strength decreased by 13.84% in set-3 And the maximum displacement by 35.46% in set-5 and the maximum strength decreased by 30.71% in Cond-4 and the maximum displacement by 63.02% in Cond-4 compared with the without pits models. Failure paths were observed in regions with reduced cross-sectional areas and a higher pit density which are consistent with the stress concentration factor.