DEVELOPMENT OF RECRYSTALLIZATION TEXTURE IN IF-STEEL - AN EFFORT TO EXPLAIN DEVELOPMENTS IN GLOBAL TEXTURE FROM MICROTEXTURAL STUDIES

Development of the recrystallization texture in IF-steel was studied b y global (X-ray diffraction) and local orientation measurements. While the X-ray orientation distribution functions (ODF) provided an overal l picture of the textural changes, orientation imaging microscopy (OIM ) results narrowed these to the respective changes in deformed and rec rystallized regions. Globally, a gradual increase in the gamma-fibre ( ND parallel to(111)) was observed to coincide with a corresponding dec rease in the alpha-fibre (RD parallel to(110)) until 70% recrystalliza tion; the rates were relatively faster during 70-96% recrystallization . During recrystallization, some of the alpha-regions/bands were consu med, while remaining alpha-regions were observed to coarsen noticeably . This may reduce the rate of alpha-fibre decay, as consumption of som e of the alpha-regions may get partially compensated by coarsening in others. After a certain amount of recrystallization (possibly 70% in o ur case), the alpha-regions may not coarsen any further and the decay may become faster. OIM observations also showed preferential nucleatio n of gamma grains, although globally no growth advantage for gamma was observed. An effort was made to estimate nucleation factors (defined as the number of grains of i orientation per i band, as measured/estim ated along normal direction) for different orientations. Estimated nuc leation factors not only provided an overall picture of the preferenti al nucleation, but possibly explained the slight strengthening in gamm a-fibre recrystallization texture with increased annealing temperature . (C) 1998 Acta Metallurgica Inc.