Effect of charging hydrogen on the tensile properties of A7N01 aluminum alloy friction stir welded joints

A7N01 aluminum alloy is widely used in rail transit industry due to its excellent comprehensive mechanical properties. However, due to its sensitivity to stress corrosion cracking (SCC), especially in hydrogen-containing moisture environment, the mechanical properties of hydrogen-charged A7N01 aluminum alloy friction stir welding (FSW) joints were tested through the tensile testing machine. The scanning electron microscopy (SEM) was used to study the tensile fracture morphology. The results indicate that the ductility and tensile strength loss of A7N01 Al alloy FSW joints are large in conditions of charging hydrogen. This is due to the embrittlement of the material caused by hydrogen infiltrating into the grain boundary of the aluminum alloy material.