Effects of Microstructure and Morphological Distribution on Hydrogen-Embrittlement Sensitivity of Ti-6al-4v Alloy Welded Joint

The effects of the organizational characteristics and morphological distribution of Ti–6Al–4V alloy welded joint on their resistance to hydrogen embrittlement were investigated. The β-phase continuity of the base material (BM) was poor, and the large volume of the striped α-phase hindered hydrogen diffusion. Consequently, the BM has low hydrogen embrittlement sensitivity. The basket-like phase distribution of the weld material (WM) had better β-phase continuity and higher phase boundary density compared with the BM, providing a more convenient channel for hydrogen diffusion and more hydrogen absorption sites. Therefore, the WM had a high hydrogen embrittlement sensitivity.