The effect of strain path reversal on high-angle boundary formation by grain subdivision in a model austenitic steel

The effects of large strain and strain path reversal on deformation microstructure development in austenite below recrystallization temperature were studied by hot torsion using an Fe-30 wt.% Ni model alloy. Results show that high-angle boundaries (HABs) can be generated by both dislocation accumulation and subgrain rotation. Multiple strain reversals lead to less well-developed HABs in the original grains compared to single reversal deformed to the same strain. This is attributed to subgrain rotation mechanism being less effective at small strains.