Microstructural evolution of pure iron during hot rolling

Abstract

AbstractThe microstructural evolution of commercially pure iron has been investigated via hot rolling. Results from optical microscopy, transmission electron microscopy, and microdiffraction show that, at the initial stage of deformation, equiaxed subgrains form at the original grain boundaries. Long layered substructures composed of parallel dense dislocation walls form within grains, and in some cases microbands are also observed. With the increase of strain, the dense dislocation walls persist and their misorientations increase. At the same time, new subboundaries with smaller misorientations form between the dense dislocation walls, and eventually fully equiaxed subgrains develop throughout the specimen. The development of the microstructures and the formation mechanism of micro bands are discussed.MST/1740