Finite element and experimental analysis of elevated-temperature fatigue behavior of IN718 alloy subjected to laser peening

摘要

Elevated-temperature fatigue life prediction method on laser peening (LP) treated IN718 alloy was proposed by using ABAQUS and MSC.Patran software. The elevated-temperature fatigue tests were subsequently performed to investigate the effects of LP on the fatigue life of specimens. Finally, the functional relationship model between fatigue life of the whole specimen and risk nodes was proposed to predict the ultimate elevated-temperature fatigue life according to experimental results and finite element analysis. The results indicated that the IN718 alloy served at 700 ℃ exhibited outstanding comprehensive mechanical properties due to strengthening phase precipitation. At elevated temperature, the relaxation degree of LP-induced residual stress and the change of mechanical properties dominated the ultimate fatigue life. The predicted fatigue life results obtained by the proposed calculated model showed an acceptable error compared with experimental results. Both simulation and experimental results indicated that LP treatment is beneficial to the improvement of the elevated-temperature fatigue properties of IN718 alloy.