Corrosion-fatigue crack propagation of aluminum alloys for high-speed trains

A modified single-edge notch tension (SENT) specimen exposed to saline environment was utilized to investigate the corrosion fatigue crack growth behaviors of 5083, 6005 and 7N01 aluminum alloys. The fatigue crack propagation life, corrosion fatigue crack rate (da/dN) were tested. The microstructures and fracture surfaces of specimens were examined by optical microscopy and scanning electron microscopy (SEM). The results showed that fatigue crack propagation rate of 7N01 in 3.5% NaCl was significantly higher than 6005 and 5083 alloys. The mechanisms of anodic dissolution and hydrogen embrittlement are used to explain the results.