Effects of Nb, V and Ti on the evolution of structure in medium carbon steels during various hot forging steps

Microalloying of medium carbon steels by Nb, V and Ti is applied for obtaining desired properties without additional heat treatment of forgings. Hot forging of long products is confined by heating the blank and hot deformation followed by air or controlled cooling. Additions of microalloying elements affect the rate of grain growth during heating blanks, recrystallization parameters of deformed austenite, temperature of gamma-alpha transformation at cooling as well as contribute to precipitation hardening of the ferrite constituent. There are numerous publications on this subject; however there are not many systematical investigations that compare the effects of Nb, V and Ti quantitatively. The current presentation is aimed at summarizing the effects of Nb, V and Ti on processes of structure evolution, parameters of final ferrite-pearlite structure as well as on the mechanical properties of medium carbon steel containing manganese and chromium. (AU) © TMS