Twinning, dynamic recovery and recrystallization in the hot rolling process of twin-roll cast AZ31B alloy

Hot-rolling experiments with a reduction from 10% to 60% in single pass were conducted on AZ31B twin-roll cast sheets. Optical microscope (OM), electron backscattered diffraction (EBSD) tests and transmission electron microscope (TEM) were used to investigate twinning and DRV/DRX behaviors at different stage in the hot-rolling process. Two types of twinning occurred in the initial stage of hot-rolling process. DRV and discontinuous recrystallization dominated at moderate strain while continuous DRX took place homogeneously throughout original grains at the largest strains.

► Two different types of twinning, {1 0 1¯ 2} and {1 0 1¯ 1}, occurred in the rolling process, and {1 0 1¯ 1} twins tended to be preferred sites for recrystallization.
► DRV and discontinuous recrystallization dominated at moderate strain in the rolling process.
► Non-basal slip was homogeneously activated at even larger strains and continuous DRX readily took place on the basis of cellular structures.