Abstract

To understand the deformation response of a polycrystalline material, it is necessary to study the factors that govern the onset of plasticity for individual grains. This is particularly true for high-ductility structural alloys that possess a stress induced phase transformation, where the character of a grain and its neighbourhood influences its behaviour. Here, a novel complex-phase steel alloy is conceived with a deliberately unstable parent phase (austenite) that enables deformation-induced martensitic transformations (DIMT) to be explored at low levels of plastic strain. This permits the DIMT to be studied, in-situ and non-destructively, using both far-field Three-Dimensional X-Ray Diffraction (3DXRD) and Electron Back-Scatter Diffraction (EBSD). Our approach uniquely tracks the martensitic transformation directly, describing the influence of grain size, orientation, and grain neighbourhood configuration with respect to the evolving per-grain stress states. In this talk, the insights will be placed in context to the future design of alloys where the deformation response can be controlled by tailoring microstructure and local or macroscopic crystal orientations.