Abstract
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With the development of light-weighting vehicles, AA5754 sheets are widely utilized as automotive structure material. Its strength and formability are greatly related to the recrystallization process. The recrystallization behavior of AA5754 sheets at high temperature in short time (in minutes) was rarely reported. In present work AA5754 sheets with cold rolling reduction from 58 to 75% was annealed in short time (max 6 min) at 310 and 320°C. Its recrystallization behavior was studied by means of microstructure observation and tensile testing. Microstructure shows that the incubation time varies in the range of 30-120 seconds with cold rolling reduction. The incubation time becomes shorter with the higher cold rolling reduction. According to the tensile strength, the recrystallization kinetics was expressed with JMAK equation. The JMAK equation fitted with recrystallization time gives a better agreement with experimental results than that fitted with annealing time. The calculated apparent activation energy for recrystallization decreases with the increasing cold rolling reduction, indicating that the recrystallization occurred much easier in AA5754 sheet with higher cold rolling reduction.