In situ neutron diffraction experiments were used to measure the tensile deformation behavior of high-manganese austenitic steels with various Al contents (0, 1.5, 2.0, 3.0wt%). Significant variations in peak shift, broadening and asymmetry of the diffraction peaks were observed in the plastic region. Diffraction peak profile analysis was used to determine microstructural parameters such as stacking/twinning fault probabilities, dislocation density and stacking-fault energy. These parameters were quantitatively correlated with the yield strength, serrated flow and strain-hardening rate during tensile deformation. The main results showed that the twin/stacking fault probability considerably decreased, from 0.05 to 0.01, and dislocation density from 1016 to 4 x 1015/m2 as a function of Al additions. The stacking-fault energy increased from 20 to 45mJ/m2; according to stacking-fault energy = 8.84wt%Al + 19.0mJ/m2.

In situ Neutron Diffraction Study of the Microstructure and Tensile Deformation Behavior in Al-Added High Manganese Austenitic Steels. J.S.Jeong, W.Woo, K.H.Oh, S.K.Kwon, Y.M.Koo: Acta Materialia, 2012, 60[5], 2290-9