Contribution of shear banding to origin of Goss texture in silicon iron

Abstract

A number of experiments involving cold rolling and annealing have been carried out on polycrystalline and single crystal silicon iron. It is shown that the microstructural state just beneath the surface of the sheet before cold rolling is an important factor in the successful development of Goss texture during simulated processing. A coarse grained surface zone encourages formation of shear bands during rolling and these become preferential sites for nucleation during primary recrystallization. Nucleation of secondary grains, which also occurs just beneath the sheet surface, appears to be dependent on the prior existence of the shear band structure. Single crystals with the orientation (111)[112] are prone to shear banding during cold rolling especially when strain aging conditions are established. During subsequent annealing the shear bands recrystallize first, producing new grains which have the Goss orientation. The texture after complete recrystallization is the same as that of the shear band nuclei. The tendency for shear banding in these crystals and the reorientations that occur during deformation and recrystallization can be understood on the basis of a crystal deformation model of shear banding.