Fatigue Behavior of Titanium Alloy Ti-4Al-2V under High Cycle Loading at Elevated Temperature

The high cycle fatigue behavior of titanium alloy Ti-4Al-2V rods with near α phase at elevated temperature（350℃） was evaluated.The traditional high cycle fatigue（HCF） tests with groupspecimen as well as the up-and-down tests were performed under bending and rotating loadings at 350℃ in air atmosphere.The experimental data were analyzed and the theoretical S-N curve,the P-S-N curve and the S-N curve for nuclear design were processed,and the fracture morphology was analyzed by SEM.The results indicate that Ti-4Al-2V rods have good resistance to high cycle fatigue and the value is 339 MPa which is slightly higher than the calculated value from the corresponding equation,and elevated temperature accelerated the oxidation of the specimen which decreased the fatigue duration when compared with the result obtained at low temperature which is around 394 MPa.