PLASTIC ANISOTROPY IN A SUPERPLASTIC DUPLEX STAINLESS-STEEL

Measurements of the plastic anisotropy in uniaxial tension of the dupl ex stainless steel, SAF2304, have been made at room temperature and un der conditions where the material was superplastic. There was signific ant plastic anisotropy in both types of deformation and there were som e similarities between the low and high temperature variations with te nsile axis orientation. Although it was possible to model the high tem perature anisotropy using a grain boundary sliding model, the assumed distribution of sliding boundaries was considered to be unrealistic. T his, together with aspects of microstructural and textural development , indicated that deformation was principally occurring by intragranula r slip with a significant contribution caused by mechanical inhomogene ity in the two-phase material. (C) 1997 Acta Metallurgica Inc.