Effect of reversion annealing on the formation of nano/ultrafine grained structure in 201 austenitic stainless steel

► The secondary increase in the martensite content after reversion annealing. ► Formation of thermally induced martensite due to carbide precipitation. ► The smallest average grain size of 70 nm is achieved by annealing at 850 °C for 15 s. ► A fully austenitic structure with grain size of 100 nm and 1370 MPa yield strength.