Effect of pre-immersion on the SCC of heat-treated AA7050 in an alkaline 3.5%NaCl

AA7050 heat-treated variously was pre-immersed in an alkaline 3.5%NaCl for 240 h, and the pre-immersion effect on its SCC in the same environment was of interest. This effect was investigated using slow strain rate test and electrochemical techniques. For the specimens experienced a specific heat treatment, the pre-immersed one revealed higher SCC-resistance than that without pre-immersion. Analysis of the corrosion products benefited to delineate the enhancement in SCC-resistance. The corrosion product on T6 was enriched with CuO. The presence of copper oxide in the corrosion product results in a better resistance to SCC for T6 than other specimens.