Development of Σ3 n CSL boundaries in austenitic stainless steels subjected to large strain deformation and annealing

The development of annealing twins was studied in chromium–nickel austenitic stainless steels subjected to cold or warm working. The annealing behavior can be characterized by an austenite reversal, recrystallization, and grain growth, depending on the deformation microstructures. The grain coarsening during recrystallization followed by a grain growth was accompanied by the development of twin-related Σ3 n CSL boundaries. The fraction of Σ3 n CSL boundaries and their density are defined by a unique parameter that is a relative change in the grain size, i.e., a ratio of the annealed grain size to that one evolved by preceding plastic working (D/D 0). The fraction of Σ3 n CSL boundaries rapidly increased at early stage of recrystallization and grain growth while the ratio of D/D 0 attained 5. Then, the rate of increase in the fraction of Σ3 n CSL boundaries slowed down significantly during further grain coarsening. On the other hand, the density of Σ3 n CSL boundaries increased to its maximum at a ratio of D/D 0 about 2.5 followed by a gradual decrease during subsequent grain growth.