Novel reconstruction approaches of austenitic annealing twin boundaries and grain boundaries of ultrafine grained prior austenite

•The morphologic and crystallographic reconstruction quality of prior austenite with annealing twin boundaries are improved effectively by a physics-based method using phase field simulation.•The calculation efficiency can be improved by two orders of magnitude after modifying the XABX algorithm.•The approximate analytic determination of orientation relationship requiring only two martensitic variants is developed.•The morphologic reconstruction of ultrafine grained prior austenite with insufficient number of martensitic variants is explored by the novel Bi-Adjacent Block method successfully.