Investigation on the superplasticity behavior of ultrahigh carbon steel

In this study, the superplasticity behavior of grain-refinement ultrahigh carbon (UHC) steel with thermomechanical process and having an average grain size of 3 μm was investigated at the eutectoid transformation points of this material with the stepped strain rates between 2 × 10−3 and 1.6 × 10−2 s−1 test method. The results showed that the best superplasticity was obtained at 735 °C and in the deformation rate range between 3.3 × 10−3 and 4.6 × 10−3 s−1. The deformation rate sensitivity exponent, m, was calculated as 0.58 in this range.