Abstract: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.

Key words: brass; corrosioninduced stress; stress corrosion cracking