Effect of Stacking Fault Energy on Cryo Deformation Behavior of Austenitic Stainless Steels

Cryorolling followed by flash annealing is one of the most promising and viable methods for modifying the mechanical properties of face centered cubic alloys. Comparative mechanical property and deformation behavior of low nickel 304 stainless steel and high nickel 310 stainless steel are reported here. Microstructural analysis has been performed to investigate the strengthening mechanisms of both steels with the change in stacking fault energy (SFE). Low SFE resulted in the formation of deformation-induced martensite and high SFE resulted in the formation of nanotwins. The dislocation density changed upon rolling, which gets recovered after flash annealing. Deformation Induced martensite formed during cryorolling is partially converted to austenite upon flash annealing in 304 stainless steel. Nano grains and bimodal structure is observed in 310 stainless steel after flash annealing.

Automated summary

Cryorolling followed by flash annealing has shown great potential for modifying the mechanical properties of face centered cubic alloys. This study compares the mechanical properties and deformation behavior of low nickel 304 stainless steel and high nickel 310 stainless steel. The strengthening mechanisms vary with the change in stacking fault energy (SFE), resulting in the formation of deformation-induced martensite and nanotwins. The dislocation density changes during rolling but recovers after flash annealing. Additionally, cryorolling partially converts deformation-induced martensite to austenite in 304 stainless steel, while flash annealing produces nano grains and a bimodal structure in 310 stainless steel.