Effects of quenching transferring time on the intergranular corrosion resistance of aluminum alloy containing Zr or free were observed by OM （optical microscope） and SEM （scanning electronic microscope）. The results reveal that with increasing in the quenching transferring time

the intergranular corrosion depth is increased

showing the fading of intergranular corrosion resistance of alloy. However

the intergranular corrosion resistance of the alloy containing Zr is superior to that of one free Zr. The increase of quenching transferring time results in widening grain boundary precipitate free zone

which is primarily responsible for the decrease of intergranular corrosion resistance. The Zr addition can increase intergranular corrosion resistance as a result of inhibiting recrystallization.