“…McEvily and Bond [25] concluded that a localized cracking process would be avoided if the film formed is nonprotective so it would per mit general corrosion to occur instead of a localized attack, or is strong enough to sustain the applied stress without rupturing. Al though the kinetics and role of tarnish formation were further studied by many authors [26][27][28][29][30][31][32][33][34][35][36], Jenkins and Durham [37] were the first to identify a more protective thin film on a-brass, by electron diffrac tion, prior to the tarnish layer formation. Leidheiser and Kissinger [38] analyzed the liquid within the propagating crack, using the tech nique developed by Brown et al [39], and observed a very high Zn content, indicating more Zn dissolution at the crack tip.…”