Development and verification of work hardening models for X2CrNiMoN25-7-4 super duplex stainless steel after sigma phase precipitation hardening used for FEM simulations.

The aim of this study was to develop numerical work hardening models for super duplex stainless steel X2CrNiMoN25-7-4. Each model accounts for changes caused by the precipitation of a known quantity (0, 20, 35, 38%) of FeCr intermetallic phase (s). The developed models were applied in FEM simulations of tensile tests for various geometries containing the same quantity of the sigma phase. Calculations were performed for two different geometries – flat and round tensile samples. Correlations between experimental and numerically simulated tensile curves were determined using Pearson's correlation coefficient. The obtained results revealed significant correlations (above 0.9955) between numerical and experimental data.