Development of recrystallization texture in IF-steel: an effort to explain developments in global texture from microtextural studies

Abstract

Development of the recrystallization texture in IF-steel was studied by global (X-ray diffraction) and local orientation measurements. While the X-ray orientation distribution functions (ODF) provided an overall picture of the textural changes, orientation imaging microscopy (OIM) results narrowed these to the respective changes in deformed and recrystallized regions. Globally, a gradual increase in the γ-fibre (ND‖〈111〉) was observed to coincide with a corresponding decrease in the α-fibre (RD‖〈110〉) until 70% recrystallization; the rates were relatively faster during 70–96% recrystallization. During recrystallization, some of the α-regions/bands were consumed, while remaining α-regions were observed to coarsen noticeably. This may reduce the rate of α-fibre decay, as consumption of some of the α-regions may get partially compensated by coarsening in others. After a certain amount of recrystallization (possibly 70% in our case), the α-regions may not coarsen any further and the decay may become faster. OIM observations also showed preferential nucleation of γ grains, although globally no growth advantage for γ was observed. An effort was made to estimate nucleation factors (defined as the number of grains of i orientation per i band, as measured/estimated along normal direction) for different orientations. Estimated nucleation factors not only provided an overall picture of the preferential nucleation, but possibly explained the slight strengthening in γ-fibre recrystallization texture with increased annealing temperature.