Tensile properties of a type 316 stainless steel strained in air and vacuum

Results on the tensile properties of a type 316 austenitic stainless steel deformed in two test environments (air and vacuum) are presented. Specimens strained in vacuum at temperatures ranging from 673 to 873 K exhibit systematically higher resistance to plastic deformation. The same applies to specimens pre-aged either in vacuum or air and strained at room temperature. The lower values of flow stress for specimens annealed/strained in air are explained in terms of free-surface softening due to stress concentrations at the oxide–substrate interface and oxidized grain boundaries in the near-surface zone.