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 723 K to 1323 K. These treatments resulted in the formation of intermetallic precipitates and strengthening of austenitic matrix. The results of compression tests show that the higher degrees of shape recovery (56 % for 4% strain) were achieved by the samples with smaller grain size (12 μm). It was also shown that the contribution of elastic shape recovery increases and the shape recovery due memory effect decreases as the austenitic matrix strengthening increases. © (2013) Trans Tech Publications, Switzerland.

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