Prediction of σ Phase Formation in Fe–Cr–Ni–Mo–N Alloys

The formation of σ phase was investigated in Fe–Cr–Ni–Mo alloys with high nitrogen content. The amounts of the σ phase are correlated with the calculated δ-Fe values. The Md-PHACOMP (Phase Computation) method, which takes into consideration the effect of nitrogen and carbon content as well as microsegregation at the interdendritic region, can predict the σ precipitations. The numerical methodology for a multi-phase-field model can be also applied to σ phase formation by δ to (γ+σ) transformation.