Stress corrosion cracking of brass in ammonia solution

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 different potentials could be measured. At the same time, susceptibility to stress corrosion cracking(SCC) of brass in the ammonia solution under various applied potentials was measured using a single edge notched specimen. At open circuit potential, both corrosion induced tensile stress and susceptibility to SCC( I σ ) had a maximum value. Both tensile stress σ p and susceptibility I σ decreased slightly under anodic polarization, but reduced steeply with the decrease in potential of cathodic polarization. At the cathodic potential of -500 mV(vs SCE), corrosion induced stress became compressive because of copper plating layer, correspondingly, susceptibility to SCC was zero. Therefore, the variation of SCC susceptibility with potential is consistent with that of the corrosion induced additive stress. [