Plastic anisotropy in a superplastic duplex stainless steel

Measurements of the plastic anisotropy in uniaxial tension of the duplex stainless steel, SAF2304, have been made at room temperature and under conditions where the material was superplastic. There was significant plastic anisotropy in both types of deformation and there were some similarities between the low and high temperature variations with tensile axis orientation. Although it was possible to model the high temperature anisotropy using a grain boundary sliding model, the assumed distribution of sliding boundaries was considered to be unrealistic. This, together with aspects of microstructural and textural development, indicated that deformation was principally occurring by intragranular slip with a significant contribution caused by mechanical inhomogeneity in the two-phase material. (C) 1997 Acta Metallurgica Inc.