Textural Analysis during Annealing of a Plain Low Carbon Steel Q235 Processed by Different Thermal Mechanical Processing Schedules

The growth behavior of ferrite grains under three different thermal mechanical processing schedules was investigated by SEM, EBSD (electron back scattering diffraction) and X-ray diffraction techniques. Results show that the relative contribution of recovery, recrystallization and grain growth was related with the status of second-phase particles and the orientations of ferrite grains. The ultra-fine ferrite grains produced by deformation-enhanced transformation had less driving force to recrystallize since less stored energy was left after deformation. They grow apparently because of the late precipitation of second-phase particles. Although ferrite deformed below A₁ temperature gained the highest stored energy and strongest texture, only partial recrystallization occurred in such grains because of the effective pinning of second-phase particles. The intensity of <111> fiber texture decreases more apparently than that of <100> fiber texture. When deformed at α+γ dual-phase region, the ferrite grains grew in the way of recovery. The recrystallization tendencies of grains with <111> and <100> orientations are different.