Microtexture Evolution and Grain Boundary Character Distribution of Interstitial-Free Steels With Moderate Levels of Cold Rolling Reductions

High-strength interstitial-free steel sheets have very good deep drawability when processed to have{111}recrystallization texture.The microtexture evolution and grain boundary character distribution of interstitial-free steels as a function of moderate levels of cold rolling reductions were investigated by the metallographic microscopy and electron backscatter diffraction technique.The results showed that there was a close relationship between microtexture and grain boundary character distribution for interstitial-free steel,especially the distribution and features of some specific types of coincident-site lattice boundaries.In addition,α-fiber texture was weakened to vanish whileγ-fiber texture strengthened gradually as cold rolling reduction was increased from 20%to 75%for cold rolled and annealed samples.Accordingly,increasing the rolling reduction from 20%to 75%would lead to a significant increase in the proportion ofΣ3boundaries.Also,it was found that the microtexture of 20%cold rolled sample would induce a high frequency ofΣ11grain boundaries,but the microtexture of 75%cold rolled sample would produce moreΣ7andΣ17grain boundaries.It was suggested that texture played a significant role in the formation of grain boundary character distribution.