Martensite and deformation twinning in austenitic steels

The structural changes that occur in highly-alloyed austenitic steels during plastic deformation have been studied as a function of temperature and plastic strain. Stress-assisted and strain-induced martensites can occur, but also, deformation twinning can be identified by transmission electron microscopy. In the high-Mn austenite of Hadfield steel deformation is controlled by slip and twinning over a wide temperature range. In high-Ni and more complex alloyed austenites (such as in TRIP steels) deformation involving martensite formation, both stress-assisted and strain-induced, but near room temperature and above the influence of mechanical twinning, is also apparent.