Recrystallization in AISI 304 austenitic stainless steel during and after hot deformation
Recovery and recrystallization were studied in a Fe-22% Cr-3% Ni ferritic stainless steel processed by bar rolling/swaging at an ambient temperature. The annealing behaviour significantly depended on the preceding cold strain. The samples processed to relatively small strain of 2.0 did not show remarkable softening upon annealing at temperatures below 600C (0.5Tm), while the heating to higher temperatures resulted in the development of conventional primary (discontinuous) recrystallization leading to a rapid annealing softening. On the other hand, the annealing behaviour of the samples processed to strain of 4.4 was characterised by a continuous recrystallization involving a rapid polygonization followed by a normal grain growth that resulted in a gradual softening upon annealing at temperatures above 400C (0.38Tm). The continuously recrystallized microstructures consisted of much finer grains than those resulted from the discontinuous recrystallization.