A high-Mn austenitic steel was deformed by cold rolling in order to study the martensitic transformation and microstructure using X-ray diffraction and electron back-scattering diffraction. Despite a heavy deformation of 70% reduction (1.2 true strain), α′-martensite could not be induced in this alloy, but about 90% of the austenite transformed to ε-martensite. A small fraction (~4%) of α′-martensite could be observed when the same alloy was subjected to low-strain compression tests in a Gleeble simulator. The stability of ε-martensite was attributed to an increase in the stacking-fault energy of the steel. This was expected to be more than 20mJ/m2, because of the increase in temperature during cold-rolling deformation.

Martensitic Transformation during Cold Rolling Deformation of an Austenitic Fe-26Mn-0.14C Alloy. P.Sahu, A.S.Hamada, T.Sahu, J.Puustinen, Y.Oittinen, L.P.Karjalainen: Metallurgical and Materials Transactions A, 2012, 43[1], 47-55