Stress corrosion cracking of α-brass in waters with and without additions

Abstract

Slow strain rate stress corrosion tests on a 0.032 pct As brass in SO2 solutions of increasing dilution eventually resulted in tests being carried out in various waters which were also found to promote cracking. A 0.002 pet As brass was also found to be susceptible to cracking in deionized water, but in brackish water or an acidified sulfate solution this brass did not display the stress corrosion cracking observed in these more aggressive solutions by the higher As brass. The addition of arsenite to distilled water or arsenate to deionized water in sufficient amounts effectively inhibited the cracking observed at controlled potentials or open circuit in these waters without the As additions. The results are interpreted as indicative of dezincification being involved in these various environments that promoted cracking, but the extent of the dezincification plays an important role in determining whether or not cracking occurs, those additions leading to rapid and massive dezincification involving redeposition of dissolved Cu not being conducive to cracking.