Influence of ausforming on substructures and shape memory behavior in Fe-28Mn-6Si-5Cr alloy

The influence of ausforming (deformation of austenite at temperatures above Md) on shape memory effect(SME) and the substructures in Fe-28Mn-6Si-5Cr (wt.%) alloy were studied, intending to reveal the dominating factor for SME in terms of microstructural characteristics in comparison with the case of thermo-mechanical training. It was found that the SME in the studied alloy could be effectively improved by ausforming at 700 degrees C for 9% tensile strain, in the process of which the oriented stacking faults and dislocations were evolved and regularly distributed in austenite. The improvement of SME by ausforming, as well as thermo-mechanical training, is attributed to the restored substructures in austenite; while there is no closely correspondent relation between SME and the strength of austenite matrix.