Research on the Thermal Deformation Behavior of C630R New Martensitic Heat-resistant Rotor Steel

Thermal compression test of C630R rotor steel was carried out by Gleeble-3800 thermal simulation testing machine at temperature range of 1 000-1 200 ℃ and strain rate of 0.01-1 s-1， the thermal deformation behavior and the influence of different process parameters on the microstructure were studied， the constitutive equation and hot processing map of the C630R rotor steel at true strain of 0.8 was constructed. The experimental results indicate that the true stress of the C630R rotor steel decreases with the enhancement of deformation temperatures to 1 200 ℃ and the reduction of true strain rate to 0.01 s-1. When the deformation temperature is higher and the compression strain rate is lower， C630R rotor steel is preferred to produce dynamic recrystallization. Thermal deformation activation energy Q of the C630R rotor steel is calculated to be 530.155 kJ/mol by using the corrected flow stress curves， and the constitutive equation is ε= 5. 85 × 1018[sinh (0. 011 4σ) ]4. 852∙ exp (-530 155/RT）），the processing maps at true strain of 0.8 are plotted．The reasonable thermal processing parameters for C630R rotor steel under true strain of 0.8 is： deformation temperature of 1 075-1 200 ℃， strain rate of 0.01-0.11 s-1.