Influence of Heat Deformation on Dynamic Recrystallization and Microstructure of Corrosion Resistant Rail Steel

High stress corrosion resistance heavy rail U68CuCr is a kind of new rail steel,the true stress and strain curve of the heavy rail under different deformation temperature,different deformation,different deformation speed were measured by one-pass compression tests with Gleeble-1500.The influences of heat deformation parameters on the dynamic recrystallization of the rail steel were analyzed.Air cooling pearlite microstructure after deformation was observed by OM and SEM,the pearlite nodule size and interlamella spacing were also measured to analyze the influence rule of heat deformation parameters on the microstructure of the rail steel.The results show that the dynamic recrystallization of U68CuCr mainly happens at higher deformed temperature,lower deformed speed and heavier deformation.With the certain deformed temperature and deformation,the dynamic recrystallzation can happen with more possibility when the deformation speed gets lower,the stress peak as well as critical strain reduces.When austenitic grain is obtained after dynamic recrystallzation,the pearlite nodule size and interlamella spacing is smaller than the one unrecrystallzation.