On the relationship between the twin internal structure and the work-hardening rate of TWIP steels

Fe-Mn-C and Fe-Mn-Si-Al TWIP steels deformed under the same conditions exhibit different work-hardening rates. The present study investigates the microstructure of plastically deformed Fe-Mn-C and Fe-Mn-Si-Al samples, particularly the internal structure of the mechanically generated twins and their topology at the grain scale. Twins in the Fe-Mn-C steel are finer and full of sessile dislocations, rendering this material distinctly stronger with an improved work-hardening rate. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.