en گروه سرامیک Ceramic Materials and Engineering Research Paper Research Paper The aim of the present study is the prediction of critical conditions (including critical strain and flow stress) for the initiation of dynamic recrystallization during thermo-mechanical processing of plain carbon steels. For this propose, torsion tests were conducted at different temperature (1050, 1100 and 1150˚C) and strain rates (0.002, 0.02 and 0.2/s). All flow curves showed a peak stress indicating that dynamic recrystallization occurs during hot deformation. The critical stress and strain were then determined based on change in strain hardening rate as a function of flow stress. Finally, the effect of deformation conditions on these parameters was analyzed. Dynamic recrystallization, Critical stress, Critical strain, Low carbon steel. 52 58 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-127-76&slc_lang=en&sid=1 M. Shaban Ghazani Mehdi.mse@gmail.com 180031947532846003020 180031947532846003020 Yes A. Vajd 180031947532846003021 180031947532846003021 No B. Mosadeg 180031947532846003022 180031947532846003022 No