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MM: Fachverband Metall- und Materialphysik

MM 17: Poster Session

MM 17.53: Poster

Monday, March 26, 2012, 17:00–19:00, Poster B

Is the epsilon-phase in deformed autenitic steel just an accumulation of stacking faults? — •Torsten Weißbach, Sebastian Schwalbe, Jürgen Kutzner, and Jens Kortus — Institut f. Theoretische Physik, TU BergAK Freiberg, 09596 Freiberg

Highly alloyed TRIP steels consisting of metastable austenite show a transformation induced by deformation to the hexagonal lattice known from the hcp phase of iron. It has been shown by other authors that the X-ray data proving this can also be interpreted as stacking faults, because they usually occur on hexagonal planes in cubic Fe. Furthermore, the stacking fault energy in TRIP steel is low compared to other steel types.

We show density functional theory calculations on Fe to address the question under which conditions the hcp phase can be stable. Because the alloyed steel exhibits considerably strained lattice parameters, we are particularly interested in the behaviour of Fe under such conditions. The Fe phases are a complicated system for DFT; calculations are known to be very sensible to the type of exchange-correlation functional.