Strengthening of stable Cr-Ni austenitic stainless steel under thermomechanical treatments

Abstract

The features of microstructure and mechanical properties of stable austenitic steel after thermomechanical treatment consisted of low-temperature deformation, deformation in the temperature range T = 273–873 K, and subsequent annealing were investigated. It is shown that under such treatment direct (γ → α′)- and reverse (α′→γ)-martensitic transformations occur in the steel. As a result of the thermomechanical treatment submicrocrystalline structural states with high density of micro- and nanotwins and localized deformation bands are formed. The strength of the steel in these structural states is several times higher than that in the initial state.