Corrosion Behavior of Hot-dip Al-Si Alloy Plate

The corrosion behavior of hot-dipped Al-Si alloy plate at different stages of the dynamic damp heat test was studied. The morphology, elements and structures of the hot-dipped Al-Si alloy plate in corrosion process were analyzed by SEM and EDS. The results showed that the corrosion process of the hot-dipped Al-Si alloy plate was a whole evolution process in an orderly manner. The change rule of the surface morphology obeyed the variation of pitting corrosion-round corrosion-flake corrosion with the increase of exposure time. The longer the exposure time, the stronger the corrosion degree, and the higher the oxygen content of the corrosion products. The corrosion of the hot-dipped Al-Si alloy was initiated with rich Si point (Si>15%) and intergranular rich Al point (Si<5%).