Dynamic Accommodation of Internal Stress and Selection of Crystallographic Orientation Relationship in Pearlite

To gain a deeper understanding of the dynamic accommodation mechanism internal stress in pearlite originating from lattice misfit between ferrite and cementite phases, parameter ratios cementite, bθ/aθ cθ/aθ, were locally analyzed detail using electron backscatter diffraction (EBSD) technique. The EBSD analysis revealed that lamellae clearly differed those spheroidized particles, indicating has certain amount as long it maintains lamellar structure. gradually decreased during isothermal holding at 923 K after pearlitic transformation due to interfacial atomic diffusion Fe atoms. However, comparison with theoretical values obtained Pitsch-Petch orientation relationship large had been already accommodated by introduction dislocations structural ledges on ferrite/cementite interfaces, i.e., is dynamically reduced two different processes; built-in upon additional time-dependent relaxation transformation. On other hand, neutron results yielded intriguingly parameters various crystallographic relationships coexist pearlite. Furthermore, elastic strain energy suggests invariant-line criterion interface plays an important role for selection