No CrossRef data available.
Published online by Cambridge University Press: 31 January 2011
The evolution of microstructure in an Fe-0.67%C steel used for railway wheels has been investigated. To elucidate the mechanism of the ultrafine microstructure which is formed on the railway wheels tread surface, we have experimentally reproduced the same microstructure using uniaxial compressive deformation and subsequent annealing at 873 K. The deformation conditions required for ultrafine microstructure formation are the initial strain rate of 1 (=100) s-1 and total strain of 0.7. The mechanism of microstructural refinement is not the primary recrystallization but continuous recrystallization, i.e., the recovery process associated with the rearrangement of accumulated dislocations during deformation and annealing at temperatures between 773 K and 873 K. The recovery process never occurs at temperatures lower than 773 K. Primary recrystallization which involves the nucleation and growth of new ferrite grains takes place at temperatures higher than 873 K.