By using Gleeble-3500 thermal mechanical simulator

deformation resistance of 150 mm casting slab of 0. 47C-0. 36Si-0. 67Mn medium carbon steel with strain 0. 1 ~0. 6 and strain rate 10 ~ 20 s

-1

at 650 ~920℃ in single pass axial compression process is tested and studied

and a math model for deformation resistance of test steel at lower temperature is established. Results show that with decreasing temperature. increasing strain and strain rate

the deformation resistance of test steel increases: in deformation at less than 700℃

due to occurrence of dynamic ferrite phase transformation

as work-hardening and dynamic phase transformation softening are going to balance the maximum value of deformation resistance occurs on curves

later with increasing deformation-inducetl ferrite amount the deformation resistance decreases. The calc

ulated value conforms to measured value

the error of forecasting deformation value is ± 13. 76 MPa.