Screening of Salt Fog Environments for Mg Alloy SCC Susceptibility

U-bend samples of Mg alloy AZ31B were subjected to continuous near-neutral salt fog exposure to evaluate the effect of a variable salt content on stress corrosion cracking (SCC) susceptibility. Using the ASTM B117 standard environment as a baseline (5 wt% NaCl (aq) at 35°C), a two order of magnitude reduction in NaCl content coincided with a change in the dominant corrosion mode from localized filament corrosion only to transgranular SCC only. …