Influence of the Crystallographic Orientation on the Yield Strength and Deformation Mechanisms of Austenitic Grains in Metastable Stainless Steels Investigated by Spherical Nanoindentation

[EN] The mechanical behavior of a metastable stainless steel is studied by 8 spherical nanoindentation, as a function of crystallographic orientation 9 of its austenitic grains. The residual imprints are analyzed by electron 10 backscattered diffraction (inverse pole figure, phase and geometrically 11 necessary dislocation maps) and atomic force microscopy. Results showed 12 that austenite grains with the most common crystallographic orientations 13 display similar elasto-to-plastic transition, being the dislocation activity by the 14 Frank-Read source the main deformation mechanism. However, the amount 15 of dislocations generated during indentation testing strongly depends on the 16 crystallographic orientation. No evidence of stress-induced phase transforma- 17 tion is observed.