Influence of phase dissolution and hydrogen absorption on the stress corrosion cracking behavior of Mg-7%Gd-5%Y-1%Nd-0.5%Zr alloy in 3.5 wt.% NaCl solution

Through investigating the influence of phase dissolution and hydrogen on the stress corrosion cracking (SCC) behavior of an as-cast Mg-7%Gd-5%Y-1%Nd-0.5%Zr alloy in 3.5 wt.% NaCl solution, it revealed that the proposed T4 treatment can improve the SCC resistance. Based on the microstructural analysis, such improvement was mainly ascribed to the complete dissolution of coarse eutectic pockets. Further analysis indicated that the SCC mechanism was associated with hydrogen embrittlement (HE). Through dissolving the eutectic pockets and alleviating the corrosion attack of Mg matrix, the influence of HE on SCC resistance of T4 samples can be weakened.