Analysis of sharp microtexture heterogeneities in a bimodal IMI 834 billet

Regions with sharp hexagonal close-packed (hcp) local textures, named macrozones, have been observed in an IMI 834 billet and analyzed in relation to the bimodal alloy microstructure. They are clearly related to regions with primary (alpha)p grains oriented around a main texture component. The resulting (alpha)p microtexture is discussed considering heterogeneous deformation and globularization of initial packets of (alpha)p lamellae. Within an hcp macrozone, several prior (beta) grain orientations were present at high temperature. The (beta) phase developed no sharp texture heterogeneities during (alpha)/(beta) working. Clusters of (beta) grains sharing close orientations and containing small grains with high angle boundaries were observed. This (beta) microtexture can result from severe (alpha)/(beta) deformation of initially large prior grains, associated with continuous dynamic recrystallization. By cooling, the (alpha)s colonies inherited from the (beta) grains and surrounding the (alpha)p grains display several texture components with the main one matching that of the (alpha)p phase. This connection seems to be due to a variant selection influenced by the presence of (alpha)p grains.