The secondary phase in the semi-continuous casting 3003 aluminum alloy treated by homogenization at different temperature was investigated by OM(optical microscope) and Kelvin bridges.The effects of homogenizing treatment on the corrosion resistance of 3003 aluminum alloy were investigated by means of linear polarization curve

AC impedance and circular anodic polarization curves methods with the help of electrochemical station

and the corrosion morphology was observed by SEM(scanning electron microscope).The results show that the secondary phase in the 3003 aluminum alloy exhibits a significant change after the homogenizing treatment at different temperatures.The quantity

distribution and morphology of the secondary phase have an important effect on the corrosion resistance of 3003 aluminum alloy.Corrosion resistance of the alloy is deteriorated with increasing in secondary phase

and it is improved with the improvement of secondary phase distribution.In addition

the corrosion resistance of the alloy with shperodized secondary phase is superior to that with coarse and sharp one.