Materials Science Forum, Vol.500-501, 155-162, 2005
Microstructural evolution of two medium carbon microalloyed steels during hot forging process
The main aim of the present investigation was to study the flow behaviour of two medium carbon microalloyed steels under hot forming conditions, and to analyse its microstructural evolution. The dependence of recrystallized grain size (D-rec) on the Zener-Hollomon parameter Z shows a bimodal behaviour with transition from single to cyclic dynamic recrystallization. Also we observed that the variation of D-rec normalized by Burgers vector (b) with sigma(ss) normalized by shear modulus (mu) shows the same bimodal behaviour cited above. The Derby's universal equation cited in literature for recrystallized grain sizes was not followed; it seems that the presence of fine precipitated particles has a clear effect on this disagreement.