The effect of free surface on strain localization is presented on the examp
le of a type 316 austenitic stainless steel deformed in two test environmen
ts lair and vacuum). Specimens strained in vacuum exhibit systematically hi
gher resistance to plastic deformation and lower strain rate sensitivity. S
uch a behavior of the material is explained in terms of free-surface soften
ing due to stress concetrations at oxide-substrate interface and oxidized g
rain boundaries in the near-surface zone.