Micro-structural study of high-Mn TWIP steels using diffraction profile analysis

We have investigated micro-structural parameters, twin and stacking fault probabilities and dislocation density, of twinning induced plasticity (TWIP) steels by using neutron diffraction profile analysis. It is observed that the addition of 1.4 wt.% Al in Fe-18Mn-0.6C steel leads to lower tensile strength and higher elongation, reducing twin formation rate. In other words, Al addition weakens the tendency of twin and stacking faults evolution under applied strain in the range of epsilon = 0.0-0.4, while the screw component of dislocations is increased. It is also confirmed that enlarged austenite grain size in TWIP steels disfavors twin and stacking fault formation. (C) 2011 Elsevier B.V. All rights reserved.