An 'Expert System' is proposed in this work. to conduct computational exploration of the deformation and restoration behavior of a medium C-Mn steel under high strain rate conditions, at elevated temperatures and complex strain paths that occur in rod rolling process. The expert system computes appropriate thermomechanical parameters necessary for describing rod rolling process in detail and then utilizes these parameters in mathematical models to determine microstructure evolution during a typical industrial-scale rod rolling process. Microstructure simulation in rod rolling is a challenging problem due to the fact that several softening mechanisms may operate sequentially or concurrently during each deformation step. Different softening mechanisms have very different impact on microstructure development and therefore it is important to investigate the particular combinations of processing conditions under which transition of operating softening mechanisms occurs. In the present work, the transition from dynamic to metadynamic recrystallization is studied in detail based on the criteria of critical strain, austenite grain size and Zener-Hollomon parameter when the interpass (interdeformation) time is very short of the order of few milliseconds during the later stages of rod rolling. Computational results are subsequently validated by comparing the program output to in-plant measured microstructure data. The proposed expert system is designed as an off-line simulation toot to examine and assess the various options for thermomechanical process optimization.