Computation of parent austenite grain orientation from product grain orientations upon displacive phase transformations

A reverse computation procedure is proposed for calculating parent austenite orientations, which are experimentally challenging to obtain, based on the final texture after austenite-to-bainite and austenite-to-martensite phase transformations. Specifically, post-transformation electron backscatter diffraction scans of bainite and martensite were carried out in order to identify the product crystal orientations within a single former austenite grain. Subsequently, the Kurdjumov–Sachs relationship was utilized to compute the parent austenite crystal orientation based on these data. The proposed method provided a unique solution for the initial austenite grain orientation in most of the cases. Overall, the proposed computational procedure constitutes a means of understanding the factors influencing microstructural evolution in displacive phase transformations. (paper)