effects of martensite reversion parameters on the formation of nano/ultrafine grain structure in aisi 304l stainless steel

Formation of nano/ultrafine grain structure in atst 304l austenitic stainless steel through the martensite reversion treatment was studied. the solution annealed specimens were cold rolled up to 95 % thickness reduction at -15 °c. the cold-rolled specimens were subjected to reversion annealing treatment at the temperature range of 700- 1000 °c for 10–150 min. microstructural evolutions were analyzed using ferritscopy, x-ray diffraction, and field emission scanning electron microscopy techniques, whereas mechanical properties were determined by the hardness test. the saturation strain during cold rolling was about 56 % reduction. the mean austenite grain size of 135 nm was obtained by 95 % cold reduction and annealing at 700 °c for 10 min. it was found that increasing cold reduction resulted in grain refinement at the same condition of reversion annealing and higher hardness.