Evaluation of Stress Corrosion Cracking Susceptibility of α-Brass in Non-Ammoniac Environments

The constant potential intermediate strain rate technique (ISRT) was used to evaluate the stress corrosion cracking (SCC) susceptibility of yellow brass in sodium sulfate and sodium sulfite solutions and in a mixture of sodium sulfate plus sodium sulfide. Parallel tests were run using the slow strain rate technique (SSRT). SCC susceptibility potential ranges and crack velocities were predicted from intermediate strain rate experiments and compared with those experimentally found in slow strain rate tests. Yellow brass was found to be susceptible to SCC under anodic conditions in Na₂SO₄ + borate solutions and mixed Na₂SO₄ + Na₂S solutions. No SCC susceptibility was observed in a 1.0 M Na₂SO₃ solution in a wide range of potentials. The predictions based on the intermediate strain rate technique correlated well with the cracking behavior observed in slow strain rate experiments.