Heterogeneity of deformation in duplex stainless steel subjected to hydrostatic extrusion

Duplex stainless-steel due to its chemical composition and ferritic — austenitic microstructure possess the best properties of both phases. Thanks to large plastic deformation it is possible to improve certain properties, primarily mechanical ones, as a result large grain refinement that can be obtained by severe plastic deformation (SPD). In the current experiment an hydrostatic extrusion (an SPD method) of commercial 1.4462 duplex stainless steel was carried out using two reduction stages leading to a cumulative deformation strain of 1.4, and then 3.8. The extrusion process led to a change in the mechanical properties in the sub-micro levels. The aim of this research was to analyze those changes in both present phases austenite and ferrite by using nano-hardness test and XRD strain analysis.