Cross-rolling mediated microstructure and texture evolution in severely cold-rolled and annealed ultrafine pearlite

Effect of cross-rolling on the evolution of microstructure and texture in pearlite was investigated in the present work. For this purpose, near pearlitic steel was cold-rolled to 95% reduction by unidirectional cold-rolling (UCR) and different cross-rolling routes. The UCR processed material showed a predominantly lamellar structure, while the microstructure development in selected cross-rolled materials was featured by the presence of profuse shear bands and severely bent lamellae. While the UCR processed materials showed the presence of the typical RD (//< 110 >) and ND (//< 111 >) fibers, the texture formation in different cross-rolled materials was featured by the strong presence of a {001}< 110 > component of the RD-fiber. The presence of the prominent {001}<110 > component could be explained by the stability of this component under cross-rolling. Recrystallization resulted in progressive spheroidization of the cementite. The pinning of the high angle boundaries by the cementite particles hindered the long-range migration of boundaries, thus inhibiting typical discontinuous recrystallization but favoring a recovery dominated softening process. The recrystallization textures in different cross-rolled materials were featured by the retention of deformation texture, namely the prominent {001}<110> component of the RD-fiber, which amply corroborated a recovery dominated mechanism. Extended annealing resulted in the onset of abnormal grain growth in selected cross-rolled materials, which appeared to affect the microtexture, while the global texture remained mostly unaffected.

Automated summary

The study found that the evolution of microstructure in pearlite is influenced by cross-rolling, resulting in differences in lamellar structure, shear bands, and bent lamellae.