Microstructural Evolution of a Pearlitic Steel Subjected to Thermomechanical Processing

Abstract

The microstructural alterations suffered during the process of drawing deformation and subsequent annealing of pearlitic steel wires, were evaluated by scanning electron microscopy and atomic force microscopy. The deformed material showed the curling structure in cross section while, in the longitudinal section, the lamellae was aligned with the drawing direction. The microstructural characterization of deformed samples also allowed observing an interlamellar spacing reduction and the intermediate lamellae alignment process. After the heat treatment at 1000ºC for 5 min the microstructure was restored, however, few recrystallized grains were observed. The recovery was the dominant phenomenon, due to factors associated with curling structure that inhibited recrystallization.

Effect of Heat Treatment on Microstructure and Mechanical Properties of Medium-Carbon Steel Drawn Wire

“…In their batch, the difference was remarkable on the following additives: + 0.097 Cu, +0.049 Cr, +0.047 Ni. According to Ribeiro Duarte et al [14], this morphology of the pearlitic colonies " aligned with drawing direction" is due to the curling structure which was observed on the cross section of the drawing wires (0.7 wt% C, 0.489 Mn, 0.225 Si, ɛ=2.52).…”