Electrochemistry of stress corrosion cracking of brass

The stress corrosion cracking (SCC) susceptibility of pure copper and two brass (copper-zinc alloy) compositions (80/20 and 60/39) was studied in several ammoniacal and nonammoniacal aqueous solutions at open circuit potential applying a constant load technique. The SCC tests, using tensile stress and loop specimens, showed pure copper to be immune in all solutions tested, the (alpha)(beta)\u27-brass (60/39) alloy to be most susceptible to SCC, and the (80/20) alloy to have intermediate SCC susceptibility. The electrochemical tests (corrosion potential and Tafel plots) have been utilized to prove the validity of the dissolution mechanism for the SCC propagation in solutions with intermediate corrosion rates ((TURN)0.1 18% nontarnishing solutions; *DOE Report IS-T-1188. This work was performed under contract No. W-7405-Eng-82 with the U.S. Department of Energy