Reverse transformation from martensite into austenite in a medium-Mn steel

The mechanism of austenite reversion from martensite in a cold rolled medium-manganese steel has been clarified. Both displacive and reconstructive transformation happens but at a specific temperature ranges. Mechanical stabilisation of martensite into austenite were observed to take place between 300 degrees C and 500 degrees C proving the transformation at this temperature range is displacive. The time-dependent characteristic and the plastic deformation stimulating austenite transformation reveal that the transformation occurs above 500 degrees C is reconstructive. A thermodynamic theory was developed to express the mechanical stabilisation phenomenon of martensite. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.