Characterization on stress-strain behavior of ferrite and austenite in a 2205 duplex stainless steel based on nanoindentation and finite element method

The stress-strain behavior of ferrite and austenite in a commercial 2205 duplex stainless steel was investigated by using nanoindentation test and microstructure-based finite element method (FEM). Results showed that the optimum load range for measuring phase properties in nanoindentation test was from 3000 μN to 7000 μN. The ferrite has slightly higher average elastic modulus than austenite, while austenite has higher average nanohardness than ferrite. Representative stress-strain curves of ferrite and austenite were determined by means of the power-law hardening and empirical relationship. Based on FEM, the differences in distribution and portion of stress-strain in local phases were visualized, and the overall flow curve of the sample 2205 was extracted, which was in good agreement with the obtained results from uniaxial tensile experiment. Keywords: Nanoindentation, Duplex stainless steel, Microstructure, Stress-strain curves, FE