Annealing of an Austenitic Stainless Steel Deformed Under Shear Loading

Microstructural evolution during reversion annealing of an AISI 304L stainless steel, plastically deformed under shear mode, was investigated for the first time. Shear deformation facilitated by a shear punch resulted in the formation of strain-induced martensite followed by local severe plastic defamation. Upon subsequent heating, high nucleation rate of austenite in the shear zone led to a more effective grain refinement compared to the conventional thermomechanical processing routes. The fine grain size of 265 nm was obtained for the holding time of 20 s at 850 °C at the end of the reversion process, which is almost half of the value obtained by the cold rolling and annealing treatment. Continued annealing resulted in significant grain coarsening with a grain growth exponent of ~ 2, denoting the importance of close controlling the annealing process for successful grain refinement. Finally, the effect of strain heterogeneity was also briefly discussed.