Stress corrosion cracking relation with dezincification layer-induced stress

Brass foil with a protective layer formed on one side was deflected during corrosion in an ammonia solution under various applied potentials, and then corrosion-induced stress generated at brass/dezincification layer under di fferent potentials could be measured. At the same time; susceptibility to s tress corrosion cracking (SCC) of brass in the ammonia solution under vario us applied potentials was measured by using a single-edge notched specimen. At open-circuit potential, both corrosion-induced tensile stress and susce ptibility to SCC (I-sigma) had a maximum value. Both tensile stress sigma ( p) and susceptibility I-sigma decreased slightly with decreasing potential under anodic polarization, but reduced steeply with a decrease in potential under cathodic polarization. At the cathodic potential of -500 mV(SCE), co rrosion-induced stress became compressive because of the copper-plating lay er; correspondingly, susceptibility to SCC was zero. Therefore, the variati on of SCC susceptibility with potential is consistent with that of the corr osion-induced additive stress.