Production of nano/submicron grained AISI 304L stainless steel through the martensite reversion process

▶ At least 50% reduction is necessary to complete the transformation of austenite to martensite at 0 °C. ▶ The parameters of Olsen-Cohen model were found as n = 4.5, α = 3.257 and β = 3.573. ▶ The appropriate grain refining zone for annealing treatment was determined. ▶ A diagram showing different zones for each level of grain sizes via annealing conditions is presented. ▶ The hardness improves 2.5 times higher after the thermo-mechanical process. ▶ Final structure exhibits not only high strength (above 1 GPa) but also good elongation (∼40%).