Deformation Induced Pearlite Transformation and Spheroidization: Effect of Alloying Additions
The aim of this research is to investigate the effect of Cr and Al (strong ferrite formers) on the strain-induced γ-to-pearlite transformation in eutectoid steels. The microstructure evolution during the hot deformation of three eutectoid steel grades was investigated using hot torsion testing. More specifically, the steels were deformed to strain levels varying from ε = 0,5 to ε = 1,5 at their specific Ar1 temperature. Hot deformation of the undercooled austenite leads to strain-induced γ-to-pearlite transformation and to the almost instantaneous spheroidization of the formed carbides. The corresponding microstructures consist of submicronic cementite particles and ferritic grains that are 1-5 μm in size. It is shown that 1,5% Cr addition and 0,5% Al addition increase the equilibrium transformation temperature but slower significantly the kinetics of the strain-induced transformation and consequently reduce the kinetics of cementite spheroidization and of ferrite recrystallization.
T. Chandra, M. Ionescu and D. Mantovani
M. Caruso et al., "Deformation Induced Pearlite Transformation and Spheroidization: Effect of Alloying Additions", Advanced Materials Research, Vol. 409, pp. 666-671, 2012