|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Ultrafine-grained and Heterostructured Materials (UFGH XII)
||Predicting the transformation strain that controls ductility and toughness in advanced steels
||Francesco Maresca, Efthymios Polatidis, Miroslav Smid, Helena Van Swygenhoven, William Curtin
|On-Site Speaker (Planned)
Nanoscale metastable austenite can be essential for obtaining improved mechanical properties such as ductility, toughness and fatigue resistance of steels. Predicting the martensitic transformation is essential to assess TRIP and guide the design of better-performing alloys. Here, we combine HR-DIC, EBSD, neutron diffraction and TEM with a new, predictive theory of martensite crystallography to determine the full 3D transformation strain in situ (“shape deformation”) in a model Fe-20.2Ni-5.4Mn (wt%) alloy. By accounting for the contribution of the crystallographic slip, the crystallographic theory predicts within experimental accuracy the in-plane strain measurements at multiple regions and strain levels. This combined experimental-theoretical analysis reveals for the first time the full, 3D transformation strain, associated with the austenite-martensite transformation in Fe-Ni-Mn. The theory can then be used to predict new, tougher alloys. This strain is also a crucial input for micromechanics, crystal plasticity simulation of multi-phase steels and to assess their plasticity and toughness.
||Computational Materials Science & Engineering, Iron and Steel, Phase Transformations