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 pct) alloy were studied in order to determine the dominating factor for SME in terms of microstructural characteristics in comparison with the case of thermomechanical training. It was found that the SME in the studied alloy could be effectively improved by ausforming at 700 C for 9 percent 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 thermomechanical training, is attributed to the restored substructures in austenite, while there is no closely correspondent relation between SME and the strength of the austenite matrix. (Author)