Phonon dispersion and elastic constants in Fe-Cr-Mn-Ni austenitic steel

The lattice dynamics of Fe-18Cr-10Mn-16Ni austenitic steel was studied by inelastic neutron scattering techniques. Phonon dispersion curves were measured in the [100], [011] and [111] directions at low wavevectors. The measured dispersion curves are similar to those of the gamma -Fe and the Fe0.75Ni0.25 alloy, but do not show the anomalous concave curvature of the T-1 [001] branch at lower wave vectors as characteristic for gamma -Fe. All available data were used for the evaluation of the atomic force constants, elastic constants and engineering elastic moduli of Fe-18Cr-10Mn-16Ni steel. (C) 2001 Kluwer Academic Publishers.