Consistent Variation of Stress Corrosion Cracking Susceptibility and Passive Film-induced Stress for 7050 Aluminum Alloy with Polarization Potential

The film-induced stress and susceptibility to stress corrosion cracking (SCC) of 7050 aluminum alloy in the chloride solution at various potentials was investigated. The results show that large tensile stress is generated by the passive film during original corrosion. The passive film induced tensile stress increases obviously with an increase in potential under anodic potential; however, it decreases with an increase in potential when the potential E ≥-1100 mVSCE while it increased when E<-1100 mVSCE under cathodic potential. The variation of film-induced stress with potential is consistent with that of the susceptibility to SCC with potential.