Shape Memory Properties of Ultrafine-Grained Austenitic Stainless Steel

Abstract

In this work the effect of grain refinement on the shape memory properties of a Fe-Mn-Si-Cr-Ni-Co-Ti alloy was evaluated using compression tests. In order to refine the microstructure, the samples were heavily deformed by equal channel angular extrusion (ECAE) and then annealed at different temperatures ranging from 450°C to 1050°C. These treatments resulted in the formation of intermetallic precipitates and strengthening of austenitic matrix. The results of compression testes show that the higher degrees of shape recovery (56 % for 4% strain) were achieved by the samples with smaller grain size (12 µm).