압력용기용 Inconel 718 합금의 상온 및 고온에서의 저주기 피로특성에 관한 연구 A Study on the Low-Cycle Fatigue Properties of Inconel 718 Alloy for Pressure Vessel under Room and High Temperatures
pp.27-32
In order to investigate the low-cycle fatigue behavior of Inconel 718 alloy used for pressure vessels, the strain-controlled fatigue test was performed in the room and high temperatures of 550°C. High temperature test was done using an electric furnace attached on the hydraulic fatigue test system. Tensile strength and elastic modulus of the Inconel 718 alloy at the temperature of 550°C decreased by 8% and 10%, respectively, compared to those at the room temperature. Subjected to the repeated cyclic loading under the strain-control, the material exhibited cyclic softening behavior with decreasing yield strength at both room and high temperatures. The low-cycle fatigue properties determined in this research could be effectively used for the fatigue life estimation of high temperature components made of Inconel 718 alloy.