Atmospheric Corrosion Behavior of Pre-strained Aluminum Alloys LY12 and LC4 in Salt Lake Environment in Western China

Atmospheric corrosion behavior of U-bended aluminum alloy plates of LY12 and LC4with/without Al cladding was investigated by field exposure in salt lake environment in Western China for 2 a. Then their surface and cross-sectional morphology was examined by metalloscope and SEM. The results showed that the corrosion behavior of the Al clad alloys LY12 and LC4 was mainly pitting corrosion within the cladding and no pits penertrating the cladding could be observed after 2 a exposure. For the bare alloys LY12 and LC4, severe stress corrosion cracking(SCC) was observed in the test. Both tensile- and compressive- stress could lead to SCC in for LY12, while only tensile stress could induce SCC for LC4 during the exposure. Exfoliation corrosion(EFC) of LY12 and LC4 occurred under compressive stress but not under tensile stress.