Role of hydrogen in stress corrosion cracking of low-strength Al-Mg alloys

There is continuing uncertainty regarding the relative roles of anodic dissolution and H induced crack growth in Al-Mg alloys containing discrete grain boundary beta phase (Al3Mg2) particles. Evidence exists for preferential anodic dissolution of the beta phase in Al; however, this dissolution cannot account for the total crack extension for material with discrete particles. There is also evidence for considerable H generation and uptake during corrosion of Al and A5083 but no direct evidence for H induced crack growth. The purpose of this paper is to review the data on crack growth of AA5083 and to identify the possible role of H.