Effect of hydrogen on stress corrosion cracking of magnesium alloy in 0.1 M Na2SO4 solution

The effect of hydrogen on stress corrosion cracking (SCC) of an as-cast MgAl9Zn1 magnesium alloy was investigated using slow strain rate test (SSRT). The results showed that hydrogen diffused to interior of matrix, enriched and formed hydride at β phase that caused the cracking of β phase. Micro-cracks initiated at β phase and combined into main crack. The main crack propagated by coalescence of the existing micro-cracks ahead. It was indicated that hydrogen embrittlement was the main mechanism for the SCC of MgAl9Zn1 alloy.